CRWR Online Report 00-4
Visual Floodplain Modeling with Geographic Information Systems (GIS)
by
Peter B. Andrysiak Jr.
Graduate Research Assistant
and
David Maidment, PhD.
Principal Investigator
May 2000
CENTER FOR RESEARCH IN WATER RESOURCES
Bureau of Engineering Research ? The University of Texas at Austin
J.J. Pickle Research Campus  Austin, TX 78712-4497
This document is available online via World Wide Web at
http://www.crwr.utexas.edu/online.html
ii
Visual Floodplain Modeling with Geographic Information Systems
(GIS)
by
Peter B. Andrysiak Jr.
Departmental Report
Presented to the Faculty of the Civil Engineering Department
of the University of Texas at Austin
in Partial Fulfillment
of the Requirements
for the Degree of
Master of Science in Engineering
The University of Texas at Austin
May 2000
iii
Acknowledgements
I am extremely grateful to many for being given the opportunity to attend the
University of Texas at Austin to be a part of this prestigious graduate
program. First and foremost I must thank the U.S. Army Corps of Engineers
for seeing the promise in my abilities and funding this degree for the last 18
months. To Dr. Maidment, my advisor, I owe a great deal of gratitude for
giving me a home in the department and supporting my efforts with his
precious time. His lessons and unparalleled knowledge shared will not be
soon forgotten.
I would also like to thank the Louisville Corps of Engineer District for providing
the opportunity to apply what I was studying. Glenn Beckham, Lynn Funke,
and Greg Pruitt were critical to my success through their insight, research
trips and the data provided. I would also like to thank Mike Heitz from the
Cincinnati Municipal Sewer District who took his personal time to track down
information and provide insight and data. The graduate students at the
Center for Research in Water Resources scholarly abilities and contributions
in this field will make a difference. I would like to thank my friends and peers:
Dan Snead, Esteban Azagra-Camino, Eric Tate, Kwabena Asante, Kim Davis,
and Jona Finndas Jonsdottir.
Finally, I would like to thank my parents for making all of this possible through
their support and love. They have always been there to set me on the right
path and for that I am eternally grateful. They are the reason that I have been
able to succeed.
May 19, 2000
iv
Abstract
Visual Floodplain Modeling with Geographical Information Systems
(GIS)
by
Peter B. Andrysiak Jr.
The University of Texas at Austin, 2000
Supervisor: David Maidment
This research involves the integration of the HEC Hydrologic Modeling
System (HEC-HMS) and HEC River Analysis System (HEC-RAS) with
Geographic Information Systems (GIS) to develop a regional model for
floodplain determination and representation.
The Corps of Engineers who have traditionally been the leaders in flood
studies and research, using the HEC-HMS hydrologic model and the HEC-
RAS hydraulic model developed at their Hydrologic Engineering Center
(HEC). These models perform relatively well but lack the necessary visual
representation aspect and still force many to plot computed elevations on
paper maps- a tedious and time consuming task that has the potential for
error. In addition, the data for these models requires a great deal of field
v
gathering of detailed terrain information. These shortcomings have
ramifications that affect the timing and costs of studies.
Recent developments in Geographic Information Systems (GIS)?based tools
can alleviate some of these shortcomings. Developments in GIS applications
allow it to work in conjunction with hydrologic and hydraulic models thus
reducing the need for field survey data and making the floodplain mapping
process more automated and visual.
The Center for Research in Water Resources at the University of Texas at
Austin is a leader in this area of floodplain modeling and mapping research.
This ongoing research is applied to Mill Creek, a study currently being
conducted by the Louisville Corps of Engineer District in Hamilton County in
southwestern Ohio
vi
Table of Contents
LIST OF TABLES VI
LIST OF FIGURES VII
1 INTRODUCTION ..................................................................................... 1
1.1 OBJECTIVES........................................................................................ 2
1.2 STUDY AREA....................................................................................... 4
1.3 LITERATURE REVIEW ........................................................................... 6
1.4 STRUCTURE OF REPORT...................................................................... 8
2 DATA DISCUSSION................................................................................ 9
2.1 GEOSPATIAL DATA (ARCVIEW GIS).................................................... 10
2.1.1 Vector Objects......................................................................... 10
2.1.2 Raster...................................................................................... 10
2.1.3 Raster-vector Data Model........................................................ 11
2.1.4 Georeferencing the Data ......................................................... 12
2.1.5 Preparing Files For Data Storage ............................................ 14
2.1.6 Data Available For Download .................................................. 14
2.1.7 Setting Parameters.................................................................. 17
2.2 HYDROLOGIC DATA (HEC-HMS) ....................................................... 20
2.2.1 Basin Model Data .................................................................... 20
2.2.2 Precipitation Model .................................................................. 21
2.2.3 Control Specifications.............................................................. 24
2.3 HYDRAULIC DATA (HEC-RAS)........................................................... 24
2.3.1 Geometry Data ........................................................................ 25
2.3.2 Flow Data ................................................................................ 25
vii
2.3.3 Plan Data................................................................................. 26
2.4 FLOODPLAIN VISUALIZATION DATA (ARCVIEW GIS).............................. 27
3 MODELING............................................................................................ 29
3.1 HEC-HMS ....................................................................................... 30
3.1.1 Loss Determination.................................................................. 31
3.1.2 Runoff Transformation............................................................. 31
3.1.3 Routing .................................................................................... 32
3.1.4 Parameter Optimization ........................................................... 33
3.2 HEC-RAS........................................................................................ 33
3.2.1 Steady Flow............................................................................. 33
3.2.2 Project Files............................................................................. 35
3.2.3 Results..................................................................................... 35
3.3 GIS-BASED APPLICATIONS................................................................. 37
4 WATERSHED DELINEATION WITH CRWR-PREPRO ........................ 39
4.1 STARTING ARCVIEW .......................................................................... 39
4.2 VIEWING THE DEM............................................................................ 40
4.3 SET ANALYSIS EXTENT ...................................................................... 41
4.4 PREPARING THE RIVER REACH FILES.................................................. 41
4.5 BURN IN THE STREAMS ...................................................................... 45
4.6 FILL SINKS IN THE DEM..................................................................... 46
4.7 COMPUTE THE FLOW DIRECTION GRID................................................ 46
4.8 COMPUTE THE FLOW ACCUMULATION GRID......................................... 47
4.9 DEFINE THE BASIC STREAM NETWORK................................................ 48
4.10 ADD A STREAM TO THE STREAM NETWORK ......................................... 50
4.11 SEGMENT STREAMS INTO STREAM LINKS ............................................ 51
4.12 FIND LINK OUTLETS........................................................................... 52
4.13 CREATING A POINT COVERAGE OF FLOW GAGING LOCATIONS .............. 52
viii
4.14 MANUALLY DEFINING WATERSHED OUTLETS....................................... 54
4.15 DELINEATE THE WATERSHEDS............................................................ 56
4.16 VECTORIZE THE STREAM AND WATERSHED GRIDS............................... 58
4.17 STATSGO SOILS AND LAND COVER/LAND USE DATA......................... 60
4.17.1 Working with Land Cover and Land Use Data......................... 61
4.17.2 Curve Number Calculation....................................................... 63
4.17.3 Soil Water Storage................................................................... 65
5 DEVELOPING A HYDROLOGIC MODEL............................................. 67
5.1 CALCULATING HYDROLOGIC ATTRIBUTES ............................................ 67
5.2 DETERMINING THE SCHEMATIC AND WRITING A BASIN FILE FOR HMS...... 69
6 MODELING WITH HMS......................................................................... 71
6.1 CREATING THE HMS COMPONENTS .................................................... 71
6.2 CREATING A PRECIPITATION MODEL ................................................... 73
6.3 CREATE CONTROL SPECIFICATIONS.................................................... 78
6.4 RUNNING A DESIGN STORM FOR CALIBRATION..................................... 79
7 CALIBRATION ...................................................................................... 83
7.1 THE ORIGINAL BASIN MODEL ............................................................. 84
7.2 CALIBRATION OF THE HMS BASIN MODEL........................................... 85
7.2.1 Loss Rates............................................................................... 86
7.2.2 Reach Routing......................................................................... 87
7.2.3 Transform: Soil Conservation Service (SCS)........................... 96
7.3 ADDITIONAL BASIN CHARACTERISTICS CONTRIBUTING TO HYDROGRAPH
CHANGES.................................................................................................... 96
8 HYDRAULIC MODELING WITH HEC-RAS ........................................ 110
8.1 DATA REQUIREMENTS...................................................................... 110
8.2 STARTING THE PROJECT.................................................................. 111
ix
8.3 IMPORTING AND EDITING GEOMETRIC DATA....................................... 112
8.4 IMPORTING AND EDITING FLOW DATA................................................ 117
8.5 EXECUTING THE MODEL................................................................... 125
8.6 VIEWING THE RESULTS .................................................................... 126
9 FLOODPLAIN MAPPING .................................................................... 132
9.1 DATA REQUIREMENTS...................................................................... 133
9.2 PROCEDURE ................................................................................... 133
9.3 IMPORTING HEC-RAS OUTPUT ....................................................... 135
9.4 STREAM CENTERLINE REPRESENTATION........................................... 138
9.5 CROSS-SECTION MAPPING .............................................................. 141
9.6 TERRAIN MODELING ........................................................................ 144
9.7 FLOODPLAIN DELINEATION ............................................................... 157
10 CONCLUSIONS AND RECOMMENDATIONS................................ 164
10.1 WATERSHED CHARACTERIZATION WITH CRWR-PREPRO ................... 165
10.2 MODELING WITH HEC-HMS............................................................. 165
10.3 MODELING WITH RAS...................................................................... 166
10.4 FLOODMAPPING WITH FLOODMAP ..................................................... 166
10.5 ADVANTAGES.................................................................................. 167
10.6 LIMITATIONS.................................................................................... 168
10.7 APPLICATIONS................................................................................. 168
10.8 RECOMMENDATIONS FOR FUTURE WORK .......................................... 169
x
List of Tables
Table 2-1. Frequency-based Precipitation Data........................................... 22
Table 4-1. Stream Gages Attribute Table..................................................... 53
Table 4-2. Land Use and Land Cover. ......................................................... 63
Table 5-1. Stream Parameter Table............................................................. 68
Table 7-1. Run 1 Data Versus Carthage Gage. ............................................ 85
Table 7-2 . Effect of Manning?s n on Stream Velocity................................... 92
Table 7-3. Basin Velocity Calculation........................................................... 93
Table 7-4. Impervious Cover Sensitivity Analysis......................................... 95
Table 7-5. Results of Adjusted Precipitation at 0200 hours........................ 105
Table 7-6. Results of Adjusted Precipitation at 0300 hours........................ 105
Table 7-7. Results of Adjusted Lag Time and Precipitation at 0300 hours. 107
Table 7-8. Results of Adjusted Precipitation at 0330 hours........................ 108
Table 8-1. DSS Data Records.................................................................... 119
Table 8-2. HMS Basin Links to RAS Cross Sections. ................................ 120
Table 8-3. Set Locations for DSS Connections.......................................... 122
Table 8-4. Profile Output Table. ................................................................. 131
xi
Table 9-1. HEC-RAS Imported Cross-section Table.................................. 137
Table 9-2. Cross Section Georeferencing. ................................................. 142
xii
List of Figures
Figure 1-1. Floodplain Visualization Methodology. 3
Figure 1-2. Ohio Watersheds. 4
Figure 1-3. HUC 05090203. 5
Figure 1-4. Mill Creek Location. 5
Figure 1-5. Example Of Digital Terrain Representation. 7
Figure 2-1. Flow of Data for Floodplain Mapping. 9
Figure 2-2. Hydrologic Cycle. Source
http://campus.esri.com/index.cfm?theme=usa. 11
Figure 2-3. Raster-Vector Data Model. Source:
http://campus.esri.com/index.cfm?theme=usa. 12
Figure 2-4. Mill Creek WWTP Precipitation Gage Data. 23
Figure 3-1. Floodplain Mapping Methodology. 29
Figure 3-2. Energy Equation Parameters for Gradually Varied Flow. Source:
Tate 1998. 34
Figure 4-1. Watershed Delineation with CRWR-PrePro. 39
Figure 4-2. Digital Elevation Model and Hydrologic Unit Code. 40
Figure 4-3. RF3 Shape File. 42
Figure 4-4. Map Calculator. 43
xiii
Figure 4-5. RF3 With "R", "S", and "T" Segments Selected. 43
Figure 4-6. Queried RF3 File. 44
Figure 4-7. RF3 with Edited Centerline. 45
Figure 4-8. Flow Direction Grid. 47
Figure 4-9. Stream Grid with 1000 Cell Threshold. 49
Figure 4-10. Stream Grid Over RF3 File. 49
Figure 4-11. Add Stream Segments. 50
Figure 4-12. Stream Links Grid. 51
Figure 4-13. Adding Gages as Outlets. 54
Figure 4-14. Louisville District?s Manual Delineated Watershed Coverage. 55
Figure 4-15. Refining Outlets for Watersheds. 56
Figure 4-16. Watershed Grid. 57
Figure 4-17. Vectorized Watershed. 59
Figure 4-18. Watershed Comparison. 59
Figure 4-19. STATSGO Soils Coverage. 61
Figure 4-20. STATSGO Soils Legend. 61
Figure 4-21. Land Use/Land Cover. 63
Figure 4-22. Land Use/Land Cover Legend. 63
xiv
Figure 4-23. Curve Number Grid. 64
Figure 4-24. Curve Number Legend. 64
Figure 4-25. Soil Storage Grid. 65
Figure 4-26. Soils Storage Legend. 66
Figure 5-1. Developing a Hydrolocic Model. 67
Figure 5-2. HMS Schematic. 70
Figure 6-1. Modeling with HEC-HMS. 71
Figure 6-2. HMS Basin Model. 73
Figure 6-3. Precipitation Model. 74
Figure 6-4. Hyetograph. 76
Figure 6-5. Thiessen Polygon. 78
Figure 6-6. Control Specifications Setup. 79
Figure 6-7. Carthage Gage Hydrograph (Velocity 1 m/s). 80
Figure 6-8. Carthage Gage Hydrograph (Velocity 0.5m/s). 81
Figure 6-9. Carthage Gage Hydrograph (Velocity 1.5m/s). 82
Figure 7-1. Carthage Gage Hydrograph (Velocity 1 m/s). 85
Figure 7-2. Channel Storage. Source Tate 1998. 89
Figure 7-3. Velocity Effects on Flow and Time of Peak. 90
xv
Figure 7-4. Channel Characteristics. 91
Figure 7-5. Channel Characteristics. 91
Figure 7-6. Effect of Manning?s n on Stream Velocity. 92
Figure 7-7. Velocity Profile Using Manning?s Equation. 94
Figure 7-8. Hydrograph at Carthage Gage with Adjusted Velocities. 95
Figure 7-9. CSO Locations. Source: http://www.orsanco.org/wwdemo.html.
98
Figure 7-10. CSO Schematic. Source:
http://www.orsanco.org/wwdemo.html. 99
Figure 7-11. CSO Outfall on Mill Creek. 100
Figure 7-12. Inflow/Inflitration Curve with Precipitation. 100
Figure 7-13. Mill Creek WWTP Flow Data on 15 and 16 April 1998. 103
Figure 7-14. Hydrograph with Precipitation Beginning at 0200 hours. 105
Figure 7-15. Hydrograph with Precipitation Beginning at 0300 hours. 105
Figure 7-16. Hydrograph with Precipitation Beginning at 0300 hours and
Adjusted Lag Times. 107
Figure 7-17. Hydrograph with Precipitation Beginning at 0330 hours and
Adjusted Lag Times. 108
Figure 8-1. Hydraulic Modeling with HEC-RAS. 110
Figure 8-2. RAS Program Screen. 111
xvi
Figure 8-3. New Project Window. 111
Figure 8-4. Geometric Data for Lower Portion of Mill Creek. 113
Figure 8-5. RAS Geometric Data. 114
Figure 8-6. RAS Cross Section Data. 115
Figure 8-7. RAS Cross Section. 116
Figure 8-8. Set Locations for DSS Connections. 118
Figure 8-9. DSS Plot. 119
Figure 8-10. Importing DSS Data. 123
Figure 8-11. Steady Flow Boundary Conditions. 124
Figure 8-12. Steady Flow Analysis Compute Window. 125
Figure 8-13. DOS Finished ? Steady Flow Analysis. 126
Figure 8-14. Bridge Cross-Section. 127
Figure 8-15. Water Surface Profile Plot. 128
Figure 8-16. X-Y-Z Perspective Plot. 129
Figure 8-17. Cross Section Output for Bridge Cross-Section. 130
Figure 9-1. Floodplain Mapping. 132
Figure 9-2. Report Generator. 136
Figure 9-3. Center Line Representation. 140
xvii
Figure 9-4. Stream Direction. 141
Figure 9-5. Stream Definition Points. 143
Figure 9-6. Cross Section Orientation. 144
Figure 9-7. Map Calculation to Convert Grid Elevation to Meters. 146
Figure 9-8. Cross-Section Profile. 147
Figure 9-9. Select By Theme Window. 149
Figure 9-10. Point Representation of DEM with Floodplain Points Eliminated.
150
Figure 9-11. Create New TIN Window. 151
Figure 9-12. TIN of Mill Creek 152
Figure 9-13. TIN with Buildings and Streets. 153
Figure 9-14. 3D Theme Properties. 154
Figure 9-15. 3D View of Mill Creek. 155
Figure 9-16. Representation of Mill Creek with Buildings set to 20 meter
Height. 155
Figure 9-17. 3D View with Levees Added. 156
Figure 9-18. 3D View of Ford Motor Company and its Levees for Protection.
157
Figure 9-19. 2-D TIN With Water Surface TIN. 158
xviii
Figure 9-20. TIN to Grid Conversion Extent. 160
Figure 9-21. 2-D TIN with Floodplain Grid. 161
Figure 9-22. Aerial 3-D View with Flooding Effects. 162
Figure 9-23. Close-up 3-D View of Flooding Effects. 162
Figure 9-24. 3-D View of 10-year Rain Event. 163
Figure 10-1. Modeling Procedure. 164
xix
List of Equations
Equation 4-1. Soil Storage. .......................................................................... 65
Equation 4-2. Initial Abstractions.................................................................. 66
Equation 7-1. Pure Lag. ............................................................................... 88
Equation 7-2. Muskingum Method................................................................ 88
Equation 7-3. Number of Subreaches.......................................................... 89
Equation 7-4. Mannings. .............................................................................. 91
Equation 7-5. SCS Lag-time......................................................................... 96
Equation 7-6. SCS Lag-time Using Curve Number. ................................... 106
Equation 7-7. SCS Lag. ............................................................................. 107
1
1 Introduction
?Around the world, unruly rivers have long driven a hard bargain. In exchange
for rich soil, irrigated land and convenient transportation, they have forced
floodplain dwellers to deal with an occasional washout. Engineers have
labored for thousands of years to lessen the risk, but their attempts at
managing Mother Nature have been mixed -- often resulting in as much
failure as success? (NOVA Online Adventures)
(http:www.pbs.org/wgbh/nova/flood/).
Although engineers continue to battle Mother Nature, the advance of
technology is turning the tide of the struggle. However, limitations still exist.
For example, the Corps of Engineers who have traditionally been the leaders
in flood studies and research, using the HEC Hydrologic Modeling System
(HEC-HMS) hydrologic model and the HEC River Analysis System (HEC-
RAS) hydraulic model developed at their Hydrologic Engineering Center
(HEC). These models perform relatively well but lack the necessary visual
representation aspect and still force many to plot computed elevations on
paper maps- a tedious and time consuming task that has the potential for
error. In addition, the data for these models requires a great deal of field
gathering of detailed terrain information. These shortcomings have
ramifications that affect the timing and costs of studies. The data collection
process is tedious and time consuming, while the lack of convincing visual
results often causes difficulty when trying to sell a particular project where
cost is shared 50/50 by local sponsors and the federal government.
Recent developments of Geographic Information Systems (GIS)?based tools
can alleviate some of these shortcomings. The literature review in this report
reveals how certain GIS applications can work in conjunction with hydrologic
2
and hydraulic models. This combination of GIS and modeling reduces the
need for field survey data and makes the floodplain mapping process more
automated and visual.
The Center for Research in Water Resources at the University of Texas at
Austin is a leader in this area of floodplain modeling and mapping research.
This research involves the integration of HEC-HMS and HEC-RAS with GIS
to develop a regional model for floodplain determination and representation.
This ongoing research is applied to a study currently being conducted by the
Louisville Corps of Engineer District in Hamilton County in southwestern Ohio.
1.1 Objectives
The purpose of this research is to validate existing floodplain determination
and visualization tools developed at CRWR and apply them on a project scale
in to assist the Louisville Corps of Engineer District and familiarize them with
existing and emerging technologies. To accomplish this task, several goals
must be met which include:
? Conduct Watershed Delineation Using Geographic Information
Systems (GIS).
? Prepare Basin Model for Use in the Hydrologic Modeling System
(HEC-HMS).
? Calibrate the HEC-HMS Hydrologic Model.
? Import HMS Results (Peak Discharges) into the River Analysis System
(HEC-RAS).
? Generate RAS Water Surface Profiles.
3
? Create Triangular Irregular Network (TIN)
? Develop a Visual Floodplain Representation.
The figure below illustrates the use of GIS to obtain the schematic and the
parameters required by HEC-HMS. The figure also shows how HEC-HMS
uses the information imported from ArcView and generates the flow discharge
values at time intervals that HEC-RAS needs. HEC-RAS generates water
surface profiles from the flow discharges and the geometric data. RAS
generates a file that allows the transfer of cross section data to include the
parameters that delineate the water surface profile for use in GIS. Once
imported into GIS, these profiles help define the flooded areas for floodplain
visualization.
Figure 1-1. Floodplain Visualization Methodology.
4
1.2 Study Area
The study area is located in Hamilton County in southwestern Ohio. Mill
Creek flows from the southeastern part of Butler County in a southerly
direction across Hamilton County and through the City of Cincinnati to its
confluence with the Ohio River at approximately river mile 472.5. The total
fall in elevation of the thalweg from the headwaters of Mill Creek to the mouth,
over a distance of approximately 28 stream miles, is about 250 feet, with an
average gradient of 0.18%.
Figure 1-2. Ohio Watersheds.
5
Figure 1-3. HUC 05090203.
Figure 1-4. Mill Creek Location.
6
The Mill Creek watershed is approximately 165 square miles in area. In the
upper half of the basin the valley bottom is wide, averaging 1-1/2 miles, but it
narrows in the downstream reaches, averaging only ? mile through the City
of Cincinnati. In the lower portions of the basin, valley walls are steep, rising
200 to 300 feet above the valley floor, but are much less steep in the
upstream areas. In 1996, the environmental interest group, American Rivers,
designated Mill Creek as the most threatened urban stream in North America
(Mill Creek Study, 1999).
1.3 Literature Review
Recent advances in GIS technology in the 1990s have improved the
capabilities of existing hydrologic and hydraulic models. Jenson and
Dominique (1988) and Jensen (1991) suggested an approach to delineate
watershed boundaries and stream networks using geographic information
extracted from digital elevation models (DEM). Later their work appeared in
the form of ArcView extensions Spatial Analyst and Watershed Delineator
distributed by ESRI.
Hellweger and Maidment (1997) accomplished an important advance in the
integration of hydrologic models and GIS, with the development of a GIS-
based tool named HECPrePro. HECPrePro is a compilation of Arc/Info
Language scripts (AMLs) and Avenue to pre-process and export spatial data
into HEC-HMS. Soon thereafter, Maidment, Olivera and Reed (1998)
developed CRWR-PrePro.
The linking of hydraulic models and GIS has resulted in various tools, which
allow for the display and analysis of floodplain maps in GIS. Beavers (1994)
created ARC/HEC2 to connect the HEC-2 hydraulic model with Arc/Info. This
7
interface is built on AML and C code and extracts terrain information from
contour coverages and exports the data into HEC-2. Once the HEC-2
execution is complete it prepares an Arc/Info-based floodplain representation.
Hydraulic modeling requires stream channel detail that is not found in a digital
elevation model (DEM). Although DEMs provide sufficient data for watershed
delineation purposes, they lack the accuracy required within the stream
channel. The degree of detail is available in a Triangular Irregular Network
(TIN). TINs can be generated in ArcView from a DEM but will lack the
necessary detail of the channel. Tate (1999) approached this problem by
developing a methodology that integrates the existing hydraulic model (HEC-
RAS) geometry data with GIS-based coverages to create TIN models.
The research presented in this report validates this evolution of floodplain
mapping methodology.
Figure 1-5. Example Of Digital Terrain Representation.
8
1.4 Structure of Report
The research detailed in this report documents an approach for visual
floodplain modeling. The report is divided into ten chapters. Chapter 1
provides an introduction to the study area and a review of the related
literature. Chapter 2 is a discussion of the data used for the analysis.
Chapter 3 outlines the technical capabilities of the computer programs used
during the research. Chapters 4 through 9 detail the procedure of application
of these data and programs to the study area. Chapter 10 includes a
discussion of the results and conclusions and recommendations. Appendix A
presents the Carthage USGS Gage data used for calibration of the hydrologic
model. Appendix B describes the recording precipitation gages within the
study area. Appendix C presents the stream parameter data used in
calibration of the hydrologic model. Appendix D specifies the watershed
parameters used in calibration of the hydrologic model. Appendix E details
the cross section data used to refine stream velocity in the hydrologic model.
Appendix F presents the Mill Creek Wastewater Treatment Plant flow data for
April 15 and 16
th
1998. Appendix G provides a data dictionary describing the
digital data used in the project.
9
2 Data Discussion
Data models are central to the application of information technology because
they are the means by which the real world is represented inside a computer.
The following data discussion explains how we use different types of data in a
logical sequence to replicate real world conditions as it is modeled in this
research. The figure below shows the sequence. The first section focuses
on the Geospatial Data that is used to represent the terrain and water in
ArcView GIS to build a hydrologic model for use in HEC-HMS. This
hydrologic representation imported into HMS is then combined with
precipitation data and control specifications to create flow and time series
data for use in a Hydraulic Data Model HEC-HMS. The flow and time series
data from HMS is imported into the hydraulic model HEC-RAS along with its
geometry data to develop water surface profiles. To close the loop, data is
then once again used in ArcView from HEC-RAS to create a visual model.
The use of the data presented here is described in Chapters 4 through 9.
Figure 2-1. Flow of Data for Floodplain Mapping.
10
2.1 Geospatial Data (ArcView GIS)
Geospatial data is a collection of themes that represent information about the
earth. ARC/INFO and ArcView GIS are built on a fundamental geographic
data model that links the spatial representation of the location of geographic
features with a tabular description of their attributes. The model can be
implemented in a discrete space representation using vector objects (points,
lines, and polygons), or continuous space representation as a raster grid.
2.1.1 Vector Objects
Vector objects include three types of elements: points, lines, and polygons. A
point is defined by a single set of Cartesian coordinates [easting(x),
northing(y)]. A line is defined by a string of points in which the beginning and
end points are called nodes, and intermediate points are called vertices. A
straight line consists of two nodes and no vertices whereas a curved line
consists of two nodes and a varying number of vertices. Three or more lines
that connect to form an enclosed area define a polygon.
Vector feature representation is typically used for linear feature modeling
(roads, lakes, etc.), cartographic base maps, and time-varying process
modeling (Tate, 1998).
2.1.2 Raster
The raster data structure consists of a rectangular mesh of points joined with
lines, creating a grid of uniformly sized square cells. Each cell is assigned a
numerical value that defines the condition of any desired spatially varied
quantity. Grids are the basis of analysis in raster GIS and are typically used
for steady-state spatial modeling and two-dimensional surface representation.
11
A land surface representation in the grid domain is called a digital elevation
model (DEM) (Tate, 1998).
2.1.3 Raster-vector Data Model
The easiest way to understand the close association between different kinds
of spatial objects is to use the hydrologic cycle where water moves through a
network of connected flow systems.
Figure 2-2. Hydrologic Cycle. Source http://campus.esri.com/index.cfm?theme=usa.
In this cycle, a watershed (polygon feature) has an associated stream
segment (line feature) and drains to an outlet (point feature). These features
are vector data models - establishing associations are difficult due to the
different spatial formats. To establish an association, a grid format is used in
a raster data model, which allows these objects to be overlaid cell by cell.
The raster data model allows one to visualize the spatial object relationships
and permits a cell-based calculation. Note that vector data models do have
some advantages over raster data models. Vector data models are precise,
have good analytic capability, and make storing and transferring data easier.
For complex hydrologic processes, an external hydrologic modeling system is
required for a thorough characterization. Representation of hydrologic
12
features in GIS provides the spatial data support for external hydrologic
models such as the Hydrologic Modeling System (HEC-HMS).
The relationship between raster and vector data models is extremely
important. There is a one-to-one correspondence between the raster and
vector representation of each hydrologic feature that allows users to switch
back and forth between the two formats depending on what of analysis they
want to perform. This is called a raster-vector data model which is defined as
a set of related data structures in both raster and vector formats in which
geographic features are represented for purposed of hydrologic modeling and
analysis.
Figure 2-3. Raster-Vector Data Model. Source:
http://campus.esri.com/index.cfm?theme=usa.
2.1.4 Georeferencing the Data
Raster and vector data for use in GIS is readily available in the United States
on the Internet at little or no cost to users. The data can be downloaded from
13
the USGS and EPA websites found below in section 2.1.6. The key to finding
the required data is the knowing the required hydrologic unit.
The United States is divided and sub-divided into successively smaller
hydrologic units which are classified into four levels: regions, sub-regions,
accounting units, and cataloging units. The hydrologic units are arranged
within each other, from the smallest (cataloging units) to the largest (regions).
Each hydrologic unit is identified by a unique hydrologic unit code (HUC)
consisting of two to eight digits based on the four levels of classification in the
hydrologic unit system.
The first level of classification divides the Nation into 21 major geographic
areas or regions. These geographic areas contain either the drainage area of
a major river, such as the Ohio region, or the combined drainage areas of a
series of rivers. Eighteen of the regions occupy the land area of the
conterminous United States. Alaska is region 19, the Hawaii Islands
constitute region 20, and Puerto Rico and other outlying Caribbean areas are
region 21.
The second level of classification divides the 21 regions into 222 subregions.
A subregion includes the area drained by a river system, a reach of a river
and its tributaries in that reach, a closed basin(s), or a group of streams
forming a coastal drainage area.
The third level of classification subdivides many of the subregions into
accounting units. These 352 hydrologic accounting units nest within, or are
equivalent to, the subregions.
The fourth level of classification is the cataloging unit, the smallest element in
the hierarchy of hydrologic units. A cataloging unit is a geographic area
representing part of all of a surface drainage basin, a combination of drainage
14
basins, or a distinct hydrologic feature. These units subdivide the subregions
and accounting units into smaller areas. There are 2150 Cataloging Units in
the Nation. More detals on hydrologic can be found at the followoing link
http://water.usgs.gov/GIS/huc.html. Mill Creek falls within HUC 05090203.
2.1.5 Preparing Files For Data Storage
Before beginning a download, two folders must be created. For practical
purposed, the two folders in this work were named Data and Millcreek. The
Data folder is used to store all downloaded files and .zip files. This folder
ensures that a clean copy of the data remains preserved in case it is needed
later. The Millcreek folder is the project-working directory. All necessary
project files are copied or extracted to this folder from the Data folder. Within
the Millcreek folder a tmp folder must also be created as required by CRWR-
PrePro. Once the data is downloaded in zip format to the data folder, it
should then be extracted to the project-working directory.
2.1.6 Data Available For Download
The EPS?s Better Assessment Science Integrating Point and Nonpoint
Sources (BASINS) website at http://www.epa.gov/OST/BASINS/ is mainly for
using GIS to assess point and nonpoint pollution sources, but it is a great
source of GIS data for download. At the site, go to Download/Basins GIS
Data. From the United States map, select Ohio. The next page displays the
HUCs of Ohio, where the general location of Mill Creek can be selected. The
Middle Ohio-Laughery HUC 05090203 page links to three data downloads
including:
BASINS Core Data (05090203_core)
15
The following is a list of shapefiles that come bundled in the Data file. The
files that were used have an asterisk at the end of the entry. Additional
shapefiles were received from the Louisville district that included buildings,
railroads, and levees.
? Land use/land cover*
? Urbanized areas*
? Populated place locations
? Soils (STATSGO)*
? Major roads*
? USGS hydrologic unit boundaries (accounting unit, cataloging unit) *
? Drinking water supply sites
? Dam sites*
? EPA regional, state, and county boundaries
? Federal and Indian Lands
? Ecoregions
? Environmental Monitoring Data
? Water quality monitoring station summaries
? Water quality observation data
? Bacteria monitoring station summaries
16
? Weather station sites
? USGS gaging stations*
? Fish and wildlife advisories
? National sediment inventory (NSI)
? Shellfish classified areas
? Clean Water Needs Survey
? Point Source Data
? Permit Compliance System (PCS) sites and computed loadings
? Industrial Facilities Discharge (IFD) sites
? Toxic Release Inventory (TRI) sites
? Superfund National Priority List (NPL) sites
? Resource Conservation and Recovery Act (RCRA) sites
Digital Elevation Model (DEM)( 05090203_dem)
This DEM is suitable for this work, but does not provide the most recent data.
The Louisville Corps of Engineer District provided the Digital Elevation Model
(DEM) for this project. The DEM is a 1
0
by 1
0
seamless version made up of
30 meter by 30-meter cells.
Reach File Version 3 (RF3)(05090203_rf3)
17
The Rf3 files for neighboring HUCs 05090202 and 05080002 were also
necessary for the procedure.
The Center for Research in Water Resources at the University of Texas at
Austin produces a collection of exercises, data, reports and information
designed to support the use of Geographic Information Systems in Hydrology
and Water Resources annually. The data is produced in CD form and can be
found at the following link.
http://internetcity.crwr.utexas.edu/gis/gishydro99/GisHyd99.htm
On the main page at the Watershed Characterization link, a number of
resources can be found. Essential for watershed delineation is Prepro04.apr,
which is found on this page. Prepro04.apr is an ArcView project file that
contains the Scripts, Menus and Buttons for running CRWR-Prepro.
Another project file that is critical to this research is Floodmap.apr. This
ArcView Project contains the scripts and menus needed for floodplain
mapping. It can be retrieved at Eric Tate?s website. The direct link to the file
for download is:
http://www.ce.utexas.edu/prof/maidment/grad/tate/research/Floodmap/webfile
s/floodmap.html The file to download is Floodmap1.zip. These project files
must be downloaded and placed in the data file.
2.1.7 Setting Parameters
Raster and vector data must be projected prior to being used. Raster data
requires ArcInfo to be projected while vector data can be easily projected in
ArcView using the Projector extension.
A new DEM comes projected using the Geographic Coordinate System.
Elevations were specified in meters. Chapter 6, Cartographic Guidelines, of
18
the Ohio Geographic Information Management Systems (GIMS) Program
website was accessed at the following link:
http://www.dnr.state.oh.us/odnr/occ/gims/hb_chpt6.as This chapter
recommends Projection/Coordinate Systems that are in accordance with
surveying law (ORC 157). The Ohio State Plane Coordinate System (OSPC)
was chosen for this project. The OSPC System is a planer Cartesian
coordinate system based on a Lambert Conformal Conic projection. Ohio has
been divided into two zones, north and south, to restrict distortion to no
greater than 1 in 10,000, or roughly one foot for every two miles. The input
and output parameters were specified in ArcInfo by starting the program and
specifying the working directory where the DEM is stored. The project
command was then used, which identifies the input projection found below
minus the text in parenthesis:
INPUT
PROJECTION GEOGRAPHIC
/*DATUM NAD83
ZUNITS METERS
UNITS DD
SPHEROID GRS1980
XSHIFT 0.0
YSHIFT 0.0
PARAMETERS
-85.000 (Standard Parallel 1)
19
-84.000 (Standard Parallel 2)
39.000 (Central Meridian)
40.000 (Reference Latitude)
Then inputting the following text into ArcInfo specified the output projection:
project cover <DEM file name>
At this point, ArcInfo identified the projection above and prompted for input of
the output parameters for the new file. The following text was then input
minus the text in parenthesis:
OUTPUT
PROJECTION LAMBERT
/*DATUM NAD83
ZUNITS NO
UNITS METERS
SPHEROID GRS1980
XSHIFT 0.0
YSHIFT 0.0
PARAMETERS
38.733333 (Standard Parallel 1)
40.033333 (Standard Parallel 2)
-82.5 (Central Meridian)
38.0 (Reference Latitude)
600000 (False Easting)
20
END
This completed the projection of the DEM into the Ohio State Plane
Coordinate System.
2.2 Hydrologic Data (HEC-HMS)
Each HEC-HMS project requires three data components: a Basin Model, a
Precipitation Model, and Control Specifications.
2.2.1 Basin Model Data
The basin model contains data, which represents the physical system. The
descriptive data is entered by the user or imported from GIS and can be
edited. Such data includes specification of the hydrologic elements of which
the basin model is comprised, information on how the hydrologic elements
are connected, and values of parameters for the hydrologic elements. The
capability to configure a basin model by ?dragging-and-dropping? icons on a
schematic display is provided. The element data can be edited with single-
element or global editors.
A basin model consists of hydrologic elements, of which there are seven
types: subbasin, routing reach, junction, reservoir, diversion, source, and
sink. The development of a basin model requires the specification of such
elements and data that controls their 'behavior'. Users can generally choose
from alternative computational methods (e.g., routing methods for a river
reach) to define such behavior (HEC-HMS Online Help, v 1.1).
For this research, the Basin Model was created using CRWR-PrePro.
CRWR-PrePRo generates this information in ArcView and writes a file that is
21
importable into HEC-HMS. The Basin Model was built using the following
spatial data:
? Digital Elevation Model representing terrain elevation for slope and
area.
? River Reach Files for Stream network with junctions and diversions.
? Curve Number Grid developed from soils data and land cover/land use
data for runoff determination.
? Point coverage of gage stations represented as junctions to link
calibrations hydrographs.
? Stream parameters (flow velocity and Muskingum X) transferred in
parameter tables.
2.2.2 Precipitation Model
The Precipitation Model is a set of information required to define historical or
hypothetical precipitation to be used in conjunction with a basin model. Types
of hypothetical storm include frequency-based and the Corps of Engineers?
Standard Project Storm. Frequency-based storms require that the user
provide rainfall depths for various durations.
22
Duration
Return Pd 5 min 15 min 1-hr 2-hr 3-hr 6-hr 12-hr 24-hr
5 15 20 120 180 360 720 1440
2-yr 0.34 0.77 1.34 1.66 1.83 2.14 2.49 2.86
5-yr 0.42 0.94 1.64 2.02 2.23 2.62 3.04 3.49
10-yr 0.48 1.08 1.88 2.31 2.55 2.99 3.47 3.99
25-yr 0.56 1.27 2.21 2.73 3.01 3.52 4.09 4.70
50-yr 0.64 1.44 2.50 3.09 3.40 3.99 4.63 5.33
100-yr 0.72 1.63 2.84 3.50 3.87 4.53 5.25 6.04
Source: Rainfall frequency atlas of the Midwest Climate Center, Huff and Angel 1999.
Table 2-1. Frequency-based Precipitation Data.
Several options exist for specifying historical precipitation: (1) utilize cell-
based precipitation as required for the Modified Clark method; (2) import
previously determined spatially-averaged precipitation; (3) specify gages and
their locations and weights and locations of index nodes, to be used in an
automated inverse distance-weighting; or (4) specify gages and associated
weights (e.g., from Thiessen polygons). The latter method is the method
used in this research. Below is an example of the incremental precipitation
plot that results from the input of recording gage data. The data for all 8
gages is in Appendix B.
23
Figure 2-4. Mill Creek WWTP Precipitation Gage Data.
With this option, weighting factors (Thiessen-type) are specified to be applied
to gaged precipitation to calculate spatially averaged precipitation for
subbasins. The USER-SPECIFIED GAGE WEIGHTS screen contains a
"notebook" with three tabs. The first tab, labeled Gages, provides for
specification of a gage ID, gage type, total storm depth, and index
precipitation for each precipitation gage (both recording and non-recording).
The second tab, Subbasins, provides for the addition of subbasins to the
precipitation model and allows for specification of index precipitation for each
subbasin. The optional specification of index precipitation for subbasins and
precipitation gages enables adjustment for bias in gage-precipitation values.
The third tab, Weights, specifies both the total-storm weight and temporal-
distribution weight for each gage (HEC-HMS Online Help, v 1.1). The
precipitation model is complete when the data from all 8 gages is entered in
the three tabs discussed above.
24
2.2.3 Control Specifications
Lastly, the Control Specifications define time-related information for a
simulation, including the starting and ending dates and the time interval for
computations. The function of control specifications is to set the starting and
ending dates and times and time (computation) interval (HEC-HMS Online
Help, v 1.1).
A variety of styles are available for entering starting and ending dates. The
month designation is not case sensitive. Months may be specified with the
first three characters of the month name. The following are examples of valid
entries for dates:
01MAR72
1 March 1972
March 1, 1972
Time is specified as a four-digit number representing 24-hour clock time. A
colon after the first two digits is optional. The following are examples of valid
entries for times:
0100
13:30
(HEC-HMS Online Help, v 1.1)
2.3 Hydraulic Data (HEC-RAS)
The data files for a HEC-RAS project are categorized as follows: plan data,
geometric data, steady flow data, unsteady flow data, sediment data, and
25
hydraulic design data. For the purposes of this research, only the first three
data files were used.
2.3.1 Geometry Data
Cross section data represent the geometric boundary of the stream. Cross
sections are located at relatively short intervals along the stream to
characterize the flow carrying capacity of the stream and its adjacent
floodplain. Cross sections are required at representative locations throughout
the stream and at locations where changes occur in discharge, slope, shape,
roughness; at locations where levees begin and end; and at hydraulic
structures (bridges, culverts, and weirs).
The required information for a cross section consists of: the river, reach and
river station identifiers; a description; X&Ycoordinates(stationandelevation
points); downstream reach lengths; Manning?s roughness coefficients; main
channel bank stations; and contraction and expansion coefficients. The
Louisville Corps of Engineer District provided the geometry data for this
research. The cross-section information was gathered either from a physical
survey or taken form topographic maps and then entered manually (HEC-
RAS Online Help, v 2.2).
2.3.2 Flow Data
Once the geometric data is entered, the necessary flow data can be entered.
Steady Flow Data consist of: the number of profiles to be computed; the flow
data; and the river system boundary conditions. At least one flow must be
entered for every reach within the system. Additionally, flow can be changed
at any location within the river system. Flow values must be entered for all
profiles. Flow values can be imported directly from the HEC-HMS run for
different hypothetical design storms. The HMS flow data at the junctions is
26
referenced to a corresponding cross-section in RAS and then imported (HEC-
RAS Online Help, v 2.2). The HMS flow data was used in RAS for this
research. The flows were taken at the time of peak flow for the Carthage
gage and imported into RAS.
Boundary conditions are necessary to establish the starting water surface at
the ends of the river system (upstream and downstream). A starting water
surface is necessary in order for the program to begin the calculations. In a
subcritical flow regime, boundary conditions are only necessary at the
downstream ends of the river system. If a supercritical flow regime is going to
be calculated, boundary conditions are only necessary at the upstream ends
of the river system. If a mixed flow regime calculation is going to be made,
then boundary conditions must be entered at all ends of the river system.
The boundary conditions editor contains a table listing every reach. Each
reach has an upstream and a downstream boundary condition. Connections
to junctions are considered internal boundary conditions. Internal boundary
conditions are automatically listed in the table, based on how the river system
was defined in the geometric data editor. The user is only required to enter
the necessary external boundary conditions (HEC-RAS Online Help, v 2.2).
The boundary condition used was critical depth for the downstream boundary.
This is explained in greater detail in section 4.6.4.
2.3.3 Plan Data
Usually the first step in performing a simulation is to put together a Plan. The
Plan defines which geometry and flow data are to be used, as well as provide
a description and short identifier for the run. If the geometry and flow data do
not exist, then this action is performed after their creation. Also included in
the plan information are the selected flow regime and the simulation options.
27
The user can select between subcritical, supercritical, or mixed flow regime
calculations (HEC-RAS Online Help, v 2.2).
2.4 Floodplain Visualization Data (ArcView GIS)
The determination and visualization of flooded areas in ArcView requires a
detailed representation of actual conditions to accurately identify the
structures and facilities affected by the water within a floodplain.
To replicate a detailed floodplain, a digital representation of the terrain (DEM)
is necessary to build a Triangular Irregular Network (TIN). Additionally,
feature themes such as buildings, roads, railroads, and levees help to
improve the visualization of the flooded areas. The most effective
representation is the TIN with the above features added in a 3-D perspective
view. To create a TIN with precise detail, RAS cross section data is required.
Below is a detailed description of what makes up a TIN. The actual
processing of a TIN is discussed in Chapter 4.
TIN is an efficient way for representing continuous surfaces as a series of
linked triangles. Although both grids and TINs can be used for surface
representation, TINs are especially useful for representing surface elevation,
subsurface elevation and terrain modeling, especially when the represented
surfaces are highly variable and contain discontinuities and breaklines.
TIN components are nodes, triangles and edges. Nodes are locations defined
by x, y and z values from which a TIN is constructed. Triangles are formed by
connecting each node with its neighbors according to the Delaunay criterion:
all sample points are connected with two neighbors to form triangles (by using
this method the triangles are as equi-angular as possible, any point on the
surface is as close as possible to a node, and the triangulation results are
28
independent of the order the points are processed). Edges are the sides of
triangles.
TINs are generated from points, polygons and lines. Points used in defining
the TIN are called mass points. Areas of constant elevation, such as water
surfaces, are called exclusion polygons. Finally, lines such as streams and
shorelines are called breaklines. Breaklines can be either hard or soft. Hard
breaklines are features like roads, streams, and shorelines, which indicate a
significant break in elevation. Soft breaklines are features like ridgelines on
rolling hills.
Ridges like these represent distinct breaks in slope but not elevation. But
since they separate watersheds, maintaining triangulation is recommended.
When a TIN is created, mass points become nodes of triangles, while
breaklines and exclusion polygon boundaries become triangle edges.
29
3 Modeling
This chapter discusses the modeling capabilities of the computer programs
used in the research. The analysis focuses first on the GIS-based
applications with CRWR-PrePro, then the hydrologic model HEC-HMS,
followed by the hydraulic model HEC-RAS. Finally, the analysis returns to
GIS using Floodmap to create a visual model. Below is a schematic that
shows the overall process. Chapter 4 documents the step-by-step application
of the computer models presented in this chapter using the data described in
Chapter 2.
Figure 3-1. Floodplain Mapping Methodology.
30
3.1 HEC-HMS
The Hydrologic Engineering Center's Hydrologic Modeling System (HEC-
HMS) provides a variety of options for simulating precipitation-runoff
processes. In addition to unit hydrograph and hydrologic routing options
similar to those in HEC-1, capabilities currently available include: a linear-
distributed runoff transformation that can be applied with gridded (e.g., radar)
rainfall data, a simple "moisture depletion" option that can be used for
simulations over extended time periods, and a versatile parameter
optimization option.
The basic framework for simulation of basin runoff is similar to that in HEC-1.
Hydrologic elements are arranged in a dendritic network, and computations
are performed in an upstream-to-downstream sequence.
Computations are performed with SI (Systeme International d`Unites) units.
However data can be entered and viewed with units in the U.S. Customary
system. The program is capable of convert input or results from one unit
system to the other.
The execution of a simulation, called a ?run?, requires specification of three
sets of data. The first, labeled Basin Model contains parameter and
connectivity data for hydrologic elements. Types of elements are: subbasin,
routing reach, junction, reservoir, source, sink, and diversion. The second
set, labeled Precipitation Model consists of meteorological data and
information required to process it. The model may represent historical or
hypothetical conditions. The third set, labeled Control Specifications, and
specifies time-related information for a simulation. A project is used to hold
the different data sets and can contain many of each type. A project also
contains at least one run and may contain many. HEC-HMS modeling results
31
can be used as input data for hydraulic modeling. HEC-HMS provides the
following options for simulating precipitation-runoff processes:
? Several alternatives for loss determination.
? Lumped or linear distributed-runoff transformation methods.
? Hydrologic routing options.
? A powerful parameter optimization system (HEC, 1999).
3.1.1 Loss Determination
The term ?losses? or ?abstractions? refers to the amount of rainfall lost to the
soil due to infiltration. Options for calculating losses for event simulation
include initial/constant, SCS Curve Number, gridded SCS Curve Numbers,
Green and Ampt, and no loss. For continuous simulation, a simple
deficit/constant loss function can be used where the user specifies a soil
moisture storage capacity, which must be filled before excess can occur. The
capacity is filled by rainfall and depleted during rain-free periods at a user-
specified monthly-average depletion rate. When the capacity is filled, loss
occurs at the specified constant rate. It is planned to incorporate detailed soil
moisture accounting options in future versions of HEC-HMS.
3.1.2 Runoff Transformation
Runoff transformations convert excess precipitation on a subbasin to direct
runoff at the subbasin outlet. Subbasin runoff can be computed in either a
lumped or linear-distributed mode. In a lumped mode, precipitation and
"losses" are spatially averaged over a subbasin. In the linear-distributed
mode, rainfall is specified on a gridded basis, and loss and excess are
32
tracked separately for each grid cell in a subbasin. Rainfall is transformed to
direct runoff with the Modified Clark method.
Transformation of precipitation excess to direct runoff can be achieved with
unit hydrograph or kinematic wave methods. A unit hydrograph may be
specified in tabular form or in terms of parameters defined by Clark, Snyder,
or SCS methods. The kinematic wave method permits definition of two
rectangular overland flow planes. Runoff from an overland flow plane may be
routed through one or two collector channels and a main channel with
kinematic wave or Muskingum Cunge methods.
A quasi-distributed treatment of subbasin runoff can be achieved with the
Modified Clark method, which is based on the Clark conceptual runoff model.
In the Modified Clark method, grid cells are superposed on the basin and
rainfall and losses are tracked uniquely for each cell. Rainfall excess from
each cell is lagged to the basin outlet and routed through a linear reservoir.
The outflows from the linear reservoir are summed and baseflow is added to
obtain a total-runoff hydrograph.
3.1.3 Routing
Routing techniques replicate the conveyance of the runoff from the reaches
within different subbasins to the end of the river basin. Routing options
include Muskingum, Modified Puls, Kinematic Wave, and Muskingum-Cunge
methods. The Kinematic Wave and Muskingum-Cunge methods may be
invoked with standard geometric shapes (e.g., circle, trapezoid) or with cross
sections defined with eight sets of X-Y coordinates and three Manning?s n
values. Capability is also provided for routing through an uncontrolled
reservoir, for which a relation between outflow and storage is required. If
more sophisticated routing methods are required because of complex
33
boundary conditions, hydrographs may be imported for use from software
such as UNET, which provides a numerical solution to the one-dimensional
St. Venant equations.
3.1.4 Parameter Optimization
Once set up, a hydrologic model requires a calibration process accomplished
by changing some user-defined parameters. The process can vary in difficulty
depending on the number of parameters or the complexity of the network. If
required, HEC-HMS provides the capability to enable automated estimation of
values for calibrating purposes.
3.2 HEC-RAS
HEC-RAS is an integrated package of hydraulic analysis programs in which
the user interacts with the system through the use of a Graphical User
Interface (GUI). The system is capable of performing Steady Flow water
surface profile calculations and will include Unsteady Flow, Sediment
Transport, and several hydraulic design computations in the future. The
results of the model can be applied in floodplain management and flood
insurance studies.
3.2.1 Steady Flow
Steady flow describes conditions in which depth and velocity at a given
channel location do not change with time. Gradually varied flow is
characterized by minor changes in water depth and velocity from cross-
section to cross-section. The primary procedure used by HEC-RAS to
compute water surface profiles assumes a steady, gradually varied flow
scenario and is called the direct step method. The basic computational
procedure is based on an iterative solution of the energy equation,
34
g
V
YZH
2
2
?
++=
, which states that the total energy (H) at any given
location along the stream is the sum of potential energy (Z + Y) and kinetic
energy
?
?
?
?
?
?
?
?
g
V
2
2
?
. The change in energy between two cross-sections is called
head loss (h
L
) (Tate, 1998). The energy equation parameters are illustrated
in the following graphic:
Figure 3-2. Energy Equation Parameters for Gradually Varied Flow. Source: Tate
1998.
Given the flow and water surface elevation at one cross-section, the goal of
the direct step method is to compute the water surface elevation at the
adjacent cross-section. Whether the computations proceed from upstream to
35
downstream or vice versa depends on the flow regime. The dimensionless
Froude number (Fr) =
gY
V
is used to characterize flow regime, where:
? Fr < 1 denotes subcritical flow
? Fr > 1 denotes supercritical flow
? Fr = 1 denotes critical flow
For a subcritical flow scenario, which is very common in natural and man-
made channels, direct step computations would begin at the downstream end
of the reach and progress upstream between adjacent cross-sections. For
supercritical flow, the computations begin at the upstream end of the reach
and proceed downstream (Tate, 1998).
3.2.2 Project Files
In HEC-RAS terminology, a Project is a set of data files associated with a
particular river system. The modeler can perform any or all of the various
types of analyses included in the HEC-RAS package as part of the project.
The data files for a project are categorized as follows: plan data, geometric
data, steady flow data, unsteady flow data, sediment data, and hydraulic
design data.
3.2.3 Results
Once the model has finished all of the computations, the modeler can begin
viewing the results. Several output features are available under the View
option from the main window. These options include: cross section plots;
profile plots; rating curve plots; X-Y-Z perspective plots; tabular output at
36
specific locations (Cross Section Table); tabular output for many locations
(Profile Table); and the summary of errors, warnings, and notes.
3.2.3.1 Cross Section Plots
The user can plot any cross section to include bridges and culverts by simply
selecting the appropriate River, Reach and River Station from the list boxes at
the top of the plot. The user can also step through the plots by using the up
and down arrow buttons. Several plotting features are available under the
Options menu of the Cross Section plot. These options include: zoom in;
zoom out; selecting which plans, profiles and variables to plot; and control
over the lines, symbols, labels, scaling, and grid options.
Hardcopy outputs of the graphics can be accomplished in two different ways.
Plots can be sent directly from HEC-RAS to whichever printer or plotter the
user has defined under the Windows Print Manager. Plots can also be sent
to the Windows clipboard. Once the plot is in the clipboard it can then be
pasted into other programs, such as a word processor. Both of these options
are available from the File menu on the various plot windows.
All of the options available in the cross section plot are also available in the
profile plot. Additionally, the user can select which specific reaches to plot
when a multiple-reach river system is being modeled.
3.2.3.2 X-Y-Z Perspective Plot
An X-Y-Z Perspective Plot is also available. The user has the option of
defining the starting and ending location for the extent of the plot. The plot
can be rotated left or right and up or down in order to get different
perspectives of the river reach. The computed water surface profiles can be
overlaid on top of the cross section data. The graphic can be sent to the
37
printer or plotter directly, or the plot can be sent through the Windows
Clipboard to other programs.
3.2.3.3 Tabular Output
Tabular output is available in two different formats. The first type of tabular
output provides detailed hydraulic results at a specific cross section location
(cross section table). The second type of tabular output shows a limited
number of hydraulic variables for several cross sections and multiple profiles.
There are several standard tables that are pre-defined and provided to the
user under the Tables menu from the profile output tables. Users can also
define their own tables by specifying what variables they would like to have in
a table. User specified table headings can be saved and then selected later
as one of the standard tables available to the project.
Tabular output can be sent directly to the printer or passed through the
clipboard in the same manner as the graphical output described previously.
This option is also available under the File menu on each of the table forms.
3.3 GIS-based Applications
Geographic Information Systems are computer environments where users
can create, manipulate, store, and display graphical elements with associated
data. GIS applications support engineering analysis in very different fields,
including hydrology and hydraulics. The GIS-based applications used in this
research are CRWR-PrePro and Floodmap, both working under the ArcView
GIS software.
CRWR-PrePro and Floodmap are ArcView extensions created by the Center
for Research in Water Resources, at the University of Texas at Austin.
CRWR PrePro generates the hydrologic elements required by HEC-HMS,
38
including the subbasins, reaches, sources, sinks and diversions. For more
information about CRWR-PrePro, the reader is referred to Olivera (1999).
Floodmap is a project containing the scripts and menus needed for floodplain
visualization and analysis in GIS by post-processing HEC-RAS data.
Floodmap can also develop a terrain model with a density of points in the
channel sufficient for hydraulic modeling.
(http://www.ce.utexas.edu/prof/maidment/g?research/Floodmap/webfiles/floo
dmap.htm).
39
4 Watershed Delineation with CRWR-PrePro
This chapter details the application of Watershed Delineation in ArcView with
CRWR-PrePro.
Figure 4-1. Watershed Delineation with CRWR-PrePro.
4.1 Starting ArcView
With ArcView operating, the project file prepro04.apr was opened. Two new
dropdown main menus, CRWR-Prepro and CRWR-Utility are now visible. In
addition, some new buttons are also visible; these new functions are
implemented by Avenue Scripts. Clicking on the Scripts icon in the Project
window shows the customized scripts used in this project. From the File/Set
Working Directory, the working directory was set to /Millcreek. Also under
40
File/Extensions the following were selected: 3D Analyst, Spatial Analyst,
CRWR Vector, CRWR Raster, Projector!, and Geoprocessing.
4.2 Viewing the DEM
In View1, using the Add Theme Button, Demgridp and Huc.shp were added
from the Millcreek directory. For Demgrip, the Data Source Type in the Add
Theme Dialog box must be set to Grid Data Source and for Huc.shp it must
be set to Feature Source Data.
Figure 4-2. Digital Elevation Model and Hydrologic Unit Code.
From the view above, it is apparent that the HUC only covers a small portion
of this DEM. Mill Creek is found in the upper right of the HUC so no other
DEMs are necessary. There is no need to buffer the HUC to allow for error,
the area under study is well within this HUC. It is recommended that DEMs
used in CRWR-PrePro not exceed 1,000,000 cells due to the fact that certain
procedures can take hours to process. The DEM above contains about
12,960,000 cells and must be reduced in size before continuing. Using
CRWR-Raster and the Clip Grid by Polygon function, the necessary portion of
41
the DEM that matched the HUC can be clipped out. When Demgridp is the
active theme, the Clip by Polygon function uses HUC.shp and performs the
function. The new DEM will resemble the intersection between the DEM and
polygon.
4.3 Set Analysis Extent
Before processing the DEM, the Analysis Extent must be set to tell ArcView
what part of the view is to be analyzed. From Analysis/Properties,setthe
Analysis Extent at the top of the window to Same as Demgridp, and set the
Analysis Cell Size in the middle of the window to Same as Demgridp. Setting
the analysis extent and keeping it consistent ensures that the various grids
generated in the analysis are locationally consistent with one another and
their cells are the same size.
4.4 Preparing the River Reach Files
The River Reach Files must be refined before they can be used in CRWR
Pre-Pro. The RF3 files from the Mill Creek HUC and two northern most
HUCs must be added to the view. The purpose of adding the additional RF3
files is to ensure the watershed area for the Mill Creek Basin is reduced as
much as possible to the actual area. The reaches from the neighboring
HUCs must be burned in to the DEM to ensure that any runoff contributing to
those reaches runs away from the Mill Creek Basin. In the view below, HUCs
05090203 (blue) and 05080002 (green) are visible. In the view, green stream
segments can be seen running away from and to Mill Creek. If the segments
running away are not considered, the area that contributes runoff to those
segments may actually be included in the Mill Creek Watershed. Though the
contribution may seem small, the aggregation across the watershed may be
significant.
42
With the RF3 images in view, the Mill Creek segments must be inspected for
larger bodies of water that are represented by their banks and not centerlines.
The network should also be proofed for breaks in the streams. Shown below
is an example of a lake in the upper portion of the basin. If the ?Burn
Streams? function were to be applied, it would burn in the banks and create
two streams in the terrain. In CRWR Pre-Pro, the centerline must be drawn in
lieu of the banks.
Figure 4-3. RF3 Shape File.
With the 05090203.shp theme highlighted, the query tool is accessed and the
following entered. This highlights the ?R? and ?S? reaches as shown below so
they can be saved as another shapefile for editing.
43
Figure 4-4. Map Calculator.
Figure 4-5. RF3 With "R", "S", and "T" Segments Selected.
Under Theme/Convert to Shapefile, a new RF3 theme was created called
Cleanrf.shp. This theme is shown below in red on top of the original RF3 file.
This is the view that was used to create the centerline of the lake. The
original RF3 file was used as a guide to aid in drawing the centerline
44
Figure 4-6. Queried RF3 File.
With the Cleanrf.shp file active, Theme/Properties was accessed and the
Edit function was then accessed. General and interactive snapping were
selected and set to .005 miles. After selecting Theme/Start Editing, the
Cleanrf.shp file is ready for the stream centerlines to be added in those areas
where required. Using the old RF3 file as a guide the centerline was added
as shown below. Once all edits are complete, it is saved by choosing
Theme/Stop Edits.
45
Figure 4-7. RF3 with Edited Centerline.
With the Mill Creek RF3 files clean and prepared for Stream Burning, all of
the RF3 files must first be merged into one theme. After loading the
Geoprocessing Wizard extension, Edit/Geoprocessing was chosen and the
three files were merged.
4.5 Burn in the Streams
The next step is to perform ?Burning Streams.? Burning Streams entails
raising the land surface cells that are off the streams by an arbitrary elevation
amount so that the streams delineated from the DEM exactly match those in
RF3.
With both Cleanrf.shp and Demgrid themes active, CRWR-PrePro/Burn
Streams was selected. In the Elevation Rise dialog box, 1000 was chosen as
the arbitrary elevation rise. Since this is the temporary grid, it was saved in
the Millcreek\tmp directory. This allows one to rebuild the project easily
should ArcView crash. Under Theme/Save Data Set, the grid was saved as
millburn. Highlighting the Burned_Dem theme and using the Identify tool near
46
the streams, it is evident that the stream cell elevations remain as they were
on the original DEM surface but the land surface elevations have been raised
1000m higher.
4.6 Fill Sinks in the DEM
Most of the DEM data are accurate; however, aberrations do occur in the
DEM which cause pits to form in the terrain. These pits need to be filled;
otherwise, they will result in the wrong flow direction. The Fill Sinks function
raises pit cell elevations to the level of the lowest neighboring cell. Only tiny
sinks will be filled, since large sinks, such as lakes, are real sinks that we do
not want to remove from the DEM.
Under CRWR-Prepro/Fill Sinks, Burned_DEM is chosen from the prompted
dialog box as the Input Theme. Burned_Dem is automatically populated in the
Input Theme 1 field and millfill is chosen as the Output Theme 1. Once OK
is selected, a blue bar can be seen running across the bottom of the View1
window to indicate that processing is occurring. When it is completed, the
new grid millfill will be added to the View window. This process is the most
time consuming of all the functions and may take some time to execute on a
slower computer. Once the millfill theme is added, the project is saved to
preserve the project in case ArcView crashes. This periodic saving should be
common practice.
4.7 Compute the Flow Direction Grid
With the DEM grid filled, the flow direction grid can be calculated using
CRWR Pre-Pro/Flow Direction. The Input Theme1 is automatically
populated with the FilledDem (millfill). This is because the theme millfill has a
theme tag of FilledDem. The theme tag helps ArcView to recognize the
intrinsic properties of the grid, no matter what the given name of the theme.
47
All of the current theme tags by choosing menu CRWR-Utility /Display
Theme Tags.
For Output Theme 1, millfdr was chosen and given and the Flow Direction
Grid was calculated. After a short period, a flow direction grid was added to
the View. For a better view of the flow direction Grid, the legend of millfdr
was opened, and in the Legend Editor, a file titled fdr.avl was applied using
the Load button. Shown below is the new flow direction grid with a 3-D-like
appearance.
Figure 4-8. Flow Direction Grid.
4.8 Compute the Flow Accumulation Grid
From CRWR-Prepro /Flow Accumulation, the Input Theme1 is
automatically populated with the flow direction grid, in this case, MCfdr. The
Output Theme 1 is entered as Mcfag (Mill Creek Flow Accumulation Grid).
After a short period, a flow accumulation grid will be added to the View. Some
faint streams can be seen running from the upper right to lower left. The
48
change in color represents the accumulation of grid cells, where the darker
color indicates that more grid cells have drained into that particular cell.
Using the Identify tool, the concept of flow accumulation can be seen. By
clicking on the most down stream portion and working upstream, the number
of cells will decrease. This is directly associated with the change in drainage
area that is associated with the number of cells. Another location to look at is
the confluence of tributaries. By first looking at the upstream portion and then
the downstream portion, the contribution by the incoming tributary or branch
can be seen.
4.9 Define the Basic Stream Network
Before constructing the stream network, the cell threshold or minimum stream
drainage area must be designated. From CRWR-PrePro /Stream Definition
(Threshold), the Input Theme1 is automatically populated with the flow
accumulation grid (Mcfag) and MCstr (Mill Creek stream Grid) is added as the
Output Theme 1.
In the prompt dialog box, the stream threshold was changed from the default
10000 to 1000 cells (0.9 KM
2
). After a short period, the stream grid MCstr
was added to the View. The stream grid has a value of 1 in each cell with a
flow accumulation value larger than 1000 and NODATA on all other cells.
49
Figure 4-9. Stream Grid with 1000 Cell Threshold.
When viewing the Merge5.shp theme (red) just below MCstr (blue) (as shown
below), some of the streams of Merge5.shp are not covered. This occurs
because the 1000 cell threshold is too large to identify some of the smaller
streams represented by Merge5.shp. Using this threshold eliminates some of
the more insignificant sub-watersheds.
Figure 4-10. Stream Grid Over RF3 File.
50
4.10 Add a Stream to the Stream Network
Although we do not want to delineate all of the extra streams described by a
Rf3 file, there will be a few streams that need to be kept for watershed
delineation. In the view below, there is an example of a stream that must be
added to MCstr. Segment #2 is a segment identified as significant to the
watershed by the Ohio EPA. If the stream grid (MCstr) does not define these
streams, streams can be added to the MCstr grid using the Edit Stream tool.
To include these segments, the Edit Stream Tool is selected and then each of
the segments on Merge5.shp not defined by stream grid MCstr is selected.
This adds a new theme named Addlines.shp. The stream traced using the
Edit Stream Tool is added to the view.
Figure 4-11. Add Stream Segments.
The new stream Addlines.shp needs to be added into the existing grid stream
network. Using CRWR-PrePro/Add Streams, a prompt dialog box will show
with the three Input Themes already populated with the proper grids. The
Output Theme name was named MCmodstr (modified stream grid).
51
Shortly after execution, a Yes/No dialog box appears. Yes is chosen to use
traced and threshold streams. The modified stream grid MCmodstr includes
both the original stream with a cell threshold 1000 and the traced stream
added.
4.11 Segment Streams into Stream Links
The Stream Link function gives each stream segment a unique ID. From
CRWR-PrePro/Stream Segmentation (Links), a dialog box pops-up, and
ModifiedStreamGrid is chosen. The two Input Themes are automatically
populated with the flow direction grid (MCfdr) and the modified stream grid
(MCmodstr). The output grid name as MClnk. Shortly after execution, the
stream link grid MClnk will be added in the view. To better view the stream
link grid, the Legend Editor is accessed, and the Unique Value is chosen for
Legend Type and Value for Values Field. For the color scheme, Fruit &
Vegetables is chosen and applied. This will show the stream grid segmented
to stream links, with each link having its own unique color and value as shown
in the legend bar.
Figure 4-12. Stream Links Grid.
52
4.12 Find Link Outlets
An outlet cell is the cell in each link that has the largest flow accumulation
value. All of the cells upstream of the outlet cell flow into the outlet cell. From
CRWR-Prepro/Outlets from Links LinkGrid is chosen to create the outlet
grids. The two Input Themes are automatically populated with the flow
accumulation grid (MCfag) and stream links grid (MClnk) and the output grid
name is designated as MCout. After execution, the resulting grid is a
scattered set of single cells, each the farthest downstream cell of a stream
link.
For a better view of the outlets grid, access the Legend Editor. Double-click
on the first color square and choose the color black in the Color Palette.
Then, on the Legend Editor, double-click on the last color square above the
No Data square. Choose the color black once again in the Color Palette. The
Color Ramp button is then clicked resulting in all of the symbols becoming
black. A view of what the outlets look like will be shown in the next section.
4.13 Creating a Point Coverage of Flow Gaging Locations
Gage locations are necessary in HEC-HMS to calibrate the flows from design
storms. In the Basins Core Data, there is a point coverage of gage stations
with attributes. This theme should be loaded, viewed, and reviewed. Using
the gage numbers, the USGS website was accessed to verify if the gages
were still active or if any others had been added or moved. It was found that
many of the gages were not active or moved while the rest did not pertain to
the Mill Creek Watershed.
All of the current gages were downloaded and the required data was entered
into an Excel Spreadsheet and saved as gages.dbf. In the spreadsheet,
several fields were entered. First was Shape followed by No_ and Name.
53
These were followed by the fields Lo_d, Lo_m and Lo_s corresponding to
the longitude degrees, minutes and seconds; while fields La_d, La_m, and
La_s correspond to the latitude degrees, minutes, and seconds. Added next
were Longitude and Latitude in decimal degrees. The last entry was
Station_, which contained the station number. (Note that Longitude =-
Lo_d - Lo_m/60 - Lo_s/3600 (negative signs because is West longitude) and
Latitude = La_d + La_m/60 + La_s/3600 ).
Once the file is created and placed in the working directory, it is added to the
project file using the Tables icon of the Project window. When opened, the
table will look as shown below.
Table 4-1. Stream Gages Attribute Table.
To create a point coverage, a new View window must be opened. Select
View/Add Event Theme, and select Gages.dbf in the Table slot, Longitude
in the X Field slot and Latitude in the Y Field slot. After clicking OK, a point
theme called Gages.dbf is created. Before adding this to the working project,
the theme must be put into the correct projection.
First, the View2 map units must be defined by clicking on View/Properties
and selecting decimal degrees in the Map Units slot of the View Properties
window. Second, the theme needs to be added to the view and Projected
from Geographic into the Ohio State Plane Projection by clicking on CRWR-
Vector/Project. Select meters the Output Units window; then select State
54
Plane in the Category slot and Ohio South in the Type slot of the Projection
Properties window. Call the projected coverage GagesPro.shp and add it to
View1 as shown below in purple. Also shown in red are the outlets defined by
CRWR-PrePro.
Figure 4-13. Adding Gages as Outlets.
To add these gages as outlets, zoom into the Mcmodstr theme to the
individual cell level. Using the add outlets tool, click on the stream segment
nearest the gage location. (When selecting a location, verify that it is not one
of the defined outlets and not less than 2 cells from an outlet.) Once an outlet
is added, a new point theme called Addasoutlets.shp is added to the view as
shown in green.
4.14 Manually Defining Watershed Outlets
Watershed delineation can be executed with the data compiled up to this
point. CRWR PrePro will use all of the outlets found in MCout and generate
one watershed per outlet. In order to keep the project consistent with the
Louisville District, outlets must be manually defined to generate the same
55
watersheds. To do this, the outlet locations must be given. Below is a
digitized version of the watersheds that were delineated by hand at the
Louisville Corps of Engineer District.
Figure 4-14. Louisville District?s Manual Delineated Watershed Coverage.
Using this as a template, outlets were manually added in an effort to replicate
the watersheds. The outlets that were selected were added to
addasoutlets.shp with the gage locations. The following is a depiction of the
outlets that were added on to the Mcmodstr theme. The breaks in the stream
really do not exist; they are caused when adding the photo to the document.
56
Figure 4-15. Refining Outlets for Watersheds.
After adding all the proposed outlets, CRWR-Prepro/Add Outlets was
selected. ModifiedStreamGrid was chosen for outlets processing. In the
prompted dialog box, five Input Themes were automatically populated.
MCmod_out was designated as the modifiedoutletsgrid and MCmod_lnk for
the modifiedlinksgrid.
A Yes/No dialog box appears, and No was chosen to use the manually
selected outlets and PrePro-selected outlets. The modified outlets grid
MCmod_out and stream links grid MCmod_lnk are added to the view.
4.15 Delineate the Watersheds
With the links and outlets finalized, the watersheds can be delineated. From
the CRWR-PrePro / Sub-Watershed Delineation menu, select
ModifiedOutletsGrid from the prompted dialog box. In the next dialog box, the
two Input Themes are automatically populated with flow direction grid MCfdr
and modified outlets grid MC_out. MCwshd is the name given to the output
watershed grid.
57
After clicking OK, the watershed grid MCwshd is added to the view. (A sub-
watershed is a zone of cells with the same cell value as the first outlet cell
they drain through.) With Mcmodstr added to the top layer in the legend, the
correlation of the streams to the watershed can be seen. To view the
watershed in a more contrasting view, the Legend Editor is accessed and
Unique Value is chosen for Legend Type, Value for Values Field. The default
Color Schemes Bountiful Harvest is applied. Notice that each of the stream
segments has a watershed associated with it. By dragging the MC_out
theme to the top of the legend bar, an outlet at the end of each stream
segment is created. Using this process, outlets can be manually adjusted by
editing addasoutlets.shp until the desired subwaterheds are achieved as
found in the figure above submitted by the Louisville District.
Figure 4-16. Watershed Grid.
58
4.16 Vectorize the Stream and Watershed Grids
Grids have been the primary data worked with to this point in the study. Grids
are excellent for cell-based analysis; however, vector data is easier to use
and store. To convert raster data to vector format, select CRWR-Prepro
/Vectorize Streams and Watersheds. In the dialog box, the Input theme is
automatically populated with the watershed grid MCwshd, and MCwshply is
the name given as the output theme name.
In the Vectorize Streams dialog box, ModifiedlinksGrid is selected and the two
input themes are already populated. MCrvr is selected as the Output Theme
name. A Yes/No dialog box for backing up the MCwshply.shp appears ?
choose NO. A prompt will then indicate that a certain number of dangling
polygons have been merged. Due to the fact that a vector polygon does not
necessarily have a square shaped border like the grid, the conversion of the
grid to a polygon sometimes creates a dangling polygon on the edge of an
existing polygon. This dangling polygon is a tiny watershed that does not
exist, and is dissolved into the parent watershed polygon to which it belongs.
(Note that the blue running status bar will stay at 100% for quite some time
before the process is complete. This should not be taken as a problem with
the program.) Once complete, the watershed polygon MCwshply.shp and the
river line MCrvr.shp are added to the view. The vectorized watershed with its
stream segments is shown below.
59
Figure 4-17. Vectorized Watershed.
Once the outlets are refined and appear to be the same as those used by the
Louisville District then the process can continue. The series of delineations
and outlet adjustments resulted in the vectorized watershed correlating to the
Louisville District?s outlets. Below on the left is the Louisville watershed and
on the right is the final watershed developed in ArcView. The difference in
area is about three square miles. The district?s figure is 165 mi
2
and the
ArcView watershed is 168mi
2
.
Figure 4-18. Watershed Comparison.
60
4.17 STATSGO Soils and Land Cover/Land Use Data
To add soils themes to the view, select a new view and add the statsgo.shp
from the core data folder in the working directory. This view reveals a large
number of Statsgo polygons, which are needed to describe the soils of the
HUC. Highlighting statsgo.shp and using the legend editor, the field Muid is
used to label the mapunits. Muid is the mapunit identification number for each
unique combination soil components depicted in Statsgo.
From the Tables icon in the Project window, the mapunit.dbf and comp.dbf
tables are added from the working directory. Each of these tables has a
number of fields that are not necessary for the project. With the mapunit.dbf
table highlighted, use Table/Properties to click off all of the checked boxes
except for Muid and Muname In the Comp.dbf table, clicked off all fields
except for Muid, Seqnum, Compname, Comppct, Slopel, Slopeh, Surftex, and
Hydgrp. The percentage of each hydrologic soil group in each map unit is
necessary for the calculation of the curve number theme. Using CRWR
PrePro/Soil Group Percentages, along with the required responses for the
map unit (mapunit.dbf) and component tables (comp.dbf) when asked, a table
called muidjoin.dbf will be created.
To clip off the excess soils coverage, use the Geoprocessing Wizard
extension found in View. With Mcwshply as the template, a new theme as
shown below will result.
61
Figure 4-19. STATSGO Soils Coverage.
Figure 4-20. STATSGO Soils Legend.
4.17.1 Working with Land Cover and Land Use Data
Land use/land cover files use the Anderson Land Use Code classification
system, in which major land use types are broken out into 9 categories
including:
1 = urban
2 = agriculture
3 = rangeland
4=forest
62
5=water
6 = wetlands
7 = barren land
8 = tundra
9 = ice and snow.
The second number describes subcategories of these principal categories
such as:
11 = urban residential
12 = urban commercial
13 = urban industrial, etc.
This land use classification of the United States was developed in the late
1970s and land use has changed since then particularly in and around cities.
Regardless, the LU/LC files are still the standard land use classification of the
United States, but are now being replaced by MRLC.
With the theme lulc.shp added to the view, the individual land uses can be
seen by accessing the Legend Editor and changing the Legend Type to
Graduated Color and the Classification Field to lulc_code. First, on the
Classify button, the number of classes was changed to 8. Second, the Value
buttons were used to change the values of each category and the Label
buttons were used to change the labels of each category. The Fill Palette was
then used to color-code each of the symbols into land use categories as seen
below. The Geoprocessing Wizard was used to clip the theme to the Mill
Creek Basin as seen below.
63
Value Label Symbol Color
0-9 Unknown White
10-19 Urban Red
20-29 Agriculture Yellow
30-39 Range Land Green
40-49 Forest Dark Green
50-59 Water Blue
60-69 Wetlands Light Blue
70-79 Barren Grey
Table 4-2. Land Use and Land Cover.
Figure 4-21. Land Use/Land Cover.
Figure 4-22. Land Use/Land Cover Legend.
4.17.2 Curve Number Calculation
By combining the land use and soils data, a curve number grid can be
generated. Soil Conservation Service (SCS) curve numbers are parameters
64
for calculating abstractions. With the soil theme and land use theme active,
select CRWR PrePro/Curve Number Grid. When prompted for the name of
the lookup table, select rcn.txt. It may be necessary to add this table to the
working directory. It can be found on the GIS Hydro ?99 website under
Watershed Characterization. When prompted for the name of table with soil
group percentages, select muidjoin.dbf. The name given to the theme is
Curvenumber. Below is a depiction of the Curve Number Grid that is
calculated after various color schemes are selected.
Figure 4-23. Curve Number Grid.
Figure 4-24. Curve Number Legend.
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4.17.3 Soil Water Storage
Using the Curve Number coverage found above, the SCS equation for Soil
Water Storage (S) is applied. The value (S) for soil storage is calculated in
inches. Once the soil water storage coverage is found, the SCS equation for
initial abstractions (I
a
) can be applied and the theme statistics accessed to
find the mean across the watershed. The equations are found below.
10
1000
?=
CN
S
Equation 4-1. Soil Storage.
Figure 4-25. Soil Storage Grid.
66
Figure 4-26. Soils Storage Legend.
SI
a
2.0=
Equation 4-2. Initial Abstractions.
The mean was converted to (mm) which is the required units for HEC-HMS.
A value of 6 mm was found to be the mean across the basin. This differs
from the 12.7 mm used by the Louisville District.
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5 Developing A Hydrologic Model
This chapter details the application of Developing a Hydrologic Model.
Figure 5-1. Developing a Hydrologic Model.
5.1 Calculating Hydrologic Attributes
To calculate the attributes, use CRWR-PrePro/DEM Based Parameters.
From the Choose an Outlets Grid window, select ModifiedOutletsGrid. In the
DEM Pre-processing: Calc. Watershed and Stream Parameters window, fill
the blanks with the following theme names: Demgridp, MCfdr, MCout,
MCWshd, MCwshply.shp, MCrvr.shp and LFP. In the first Calculation Method
window, SCS is selected for the abstractions method, and in the second
68
Calculation Method window, SCS is selected for the lag-time method. Yes is
selected in both Input Warning windows. The Curve Number theme is
selected for the Curve Number Grid.
In the Time-Step window, 1-30 minutes is selected and in the Time-Step
[minutes] window, 15 is selected. For Select Stream Input File (Grid_code)
window, select StreamP.txt from the working directory. This table can be
found on the GIS Hydro ?99 Website under Watershed Characterization. This
table will require modification for each project. This particular one was
developed for the Guadalupe basin in Texas. The main field that must be
adjusted is Grid-code. Using the vectorized stream theme for the watershed,
access the attributes table to view the Grid-code numbers assigned. These
numbers must be the same ones used for the StreamP.txt. A sample table is
shown below with the stream parameters: flow velocity = 1 m/s and
Muskingum X = 0.2.
Table 5-1. Stream Parameter Table.
69
This process has added fields to the attribute tables of MCwshply and MCrvr
and populated them with values that represent the hydrologic parameters of
the feature elements.
The fields added to the MCwshply table are: LngFlwPth (length of longest
flow-path), Slope (slope of longest flow-path), Baseflow (baseflow method),
Transform (unit hydrograph model), LossRate (loss rate method), CurveNum
(average curve number), InitLoss (initial loss for the initial plus constant rate
loss method), CLossRate (constant rate loss for the initial plus constant rate
loss method), WVel (average velocity of longest flow-path), and LagTime (lag
time for the SCS unit hydrograph). The fields added to the MCrvr table are:
StreamVel (flow velocity), MuskX (Muskingum X), Route (flow routing
method), MuskK (Muskingum K), NumReachN (number of subreaches for
Muskingum flow routing method),and LagTime (lag time for pure lag flow
routing method).
5.2 Determining the schematic and writing a basin file for HMS
The HMS schematic is a conceptual model that captures the connectivity
between the different elements of the hydrologic system. The HMS basin file
is an ASCII file, readable by HMS, which includes all the information stored in
the schematic.
To transfer the hydrologic attributes calculated in 4.3.2 to the schematic and
basin file, it is necessary to add to the project the following tables from the
working directory: hecsub.dbf, hecjunct.dbf, hecreach.dbf, hecres.dbf,
hecsink.dbf, hecsource.dbf and hecdiv.dbf. This is done in the project
window under Tables/Add.
To determine the schematic and write the basin file for HMS, the
AddAsOutlets.shp, MCwshply.shp and MCrvr.shp themes must be active prior
70
to using CRWR-PrePro/HMS Schematic. In the HECPREPRO window fill the
six blanks with the following strings or values: yes, default, 23, 2,
MCBasinSCSv1 and Mill Creek BasinSCSv1. The Hydrol#.shp and
Hydrop#.shp as well as Syml#.shp and Symp#.shp store all the relevant
information of the hydrologic system necessary for HMS. Additionally,
Syml#.shp and Symp#.shp are the stick diagrams of the system. A text file
called MCbasinSCSv1.basin has also been created in the process, which is
the basin file for HMS. Below is the view that will be generated in the
process.
Figure 5-2. HMS Schematic.
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6 Modeling with HMS
This chapter details the application of Modeling with HMS.
Figure 6-1. Modeling with HEC-HMS.
6.1 Creating the HMS components
When HMS 1.1 is opened, a HMS Project Definition window will appear. A
new HMS project is created using File/New Project. In the HMS * NEW
PROJECT window, enter a name in the Project slot such as Mill Creek Basin.
To import the MCbasinSCSv1.basin file created in GIS, Edit/Basin
Model/Import is accessed. In the HMS Basin Model * IMPORT BASIN
72
MODEL window, basin file is selected from the working directory under tmp.
The file description Mill Creek BasinSCSv1 will appear but not the file name.
With the basin Model opened, some editing is required. Earlier in the project
lakes were taken out of the river reach file and replaced by centerlines.
These lakes were manmade and created by dams. In HMS, dams are
replicated by reservoirs. This is made easy in HMS by simply adding the new
element. In this case, outlets were used where the dams were located earlier
in the project so they only need to be replaced. Outlets become junctions in
HMS. Find the junction that corresponds to the dam location, and replace
using Edit/Delete Element(s). Then using Edit/New Element/Reservoir a
reservoir is added to the view.
The new element must be moved into place then connected to its respective
neighboring elements. To do this, the up stream basin is connected by right
clicking and selecting Connect Down Stream. Using the cross hair, the
reservoir is selected and connected. The same process is used to connect
the reservoir to the downstream reach. This process is done for West Fork
Mill Creek Lake (Reservoir-1) and Sharon Lake (Reservoir-2) as shown
below. After opening the Reservoir icon, parameters must be entered for its
use. In both reservoirs, a storage/discharge relationship was used with a
given initial discharge. The Louisville District provided the values used in the
model. The other parameter that must be added to the basin file is the initial
losses for each basin. Double-click on each basin to add the initial losses.
The value of 6mm was used on each basin; this was calculated using the soil
storage grid developed above.
73
Figure 6-2. HMS Basin Model.
6.2 Creating a Precipitation Model
To create a precipitation model, click on Edit/Precipitation Model/New, and
then write Thiessen8 in the Precipitation Model and Description slots and click
OK. The next view is the HMS Precipitation Model - Method Select Window,
select User Specified Gage Weighting.
With this option, you specify weighting factors (Thiessen-type) to be applied
to gaged precipitation to calculate spatially averaged precipitation for
subbasins. The User-Specified Gage Weights Screen contains a "notebook"
with three tabbed sections as shown below. The first, labeled Gages,
provides for specification of a gage ID, gage type, total storm depth, and
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index precipitation for each precipitation gage (both recording and non-
recording). The second section, Subbasins, provides for the addition of
subbasins to the precipitation model, and allows for specification of index
precipitation for each subbasin. The optional specification of index
precipitation for subbasins and precipitation gages enables adjustment for
bias in gage-precipitation values. The third section, Weights, specifies both
the total-storm weight and temporal-distribution weight for each gage.
Figure 6-3. Precipitation Model.
The first tab is Gages. On this sheet, you specify the gages that are to be
used for the design storm. Two gage types can be used with the method -
recording and non-recording gages.
75
Gages for total storm precipitation (i.e., non-recording gages) can be entered
in the Gages section by using Edit/Gage Data/Precipitation and selecting
the Add Total-Storm (NR) Gage button and entering a gage name and
appropriate storm depth. Non-Recording gages that are entered in this
manner can only be accessed by the current precipitation model. Recording
gage IDs are obtained by selecting them from the Gage Selection List, which
is accessed by clicking the Gage Select button. A total-storm depth is not
normally entered for recording gages but can optionally be added. When
total-storm depth is specified for recording gages, the individual precipitation
values will be scaled so that the total-storm rainfall will equal the specified
amount.
Recording precipitation gage data must have been previously entered before
it can be referenced from the Gage Select button. The gage type for both
recording and non-recording gages is entered automatically. Using
Edit/Gage Data/Precipitation, recording gage data for an actual storm can
be entered. The storm used for this project can be found in the Control
Specifications section. The gage data for this design storm was received from
the Cincinnati Municipal Sewer District (MSD). Mike Heitz from the MSD
provided eight recording gages located in the basin. The precipitation data is
found in Appendix B. After entering values, the gages are stored for use in
other projects as well and added to the model. Below is an example of the
incremental hyetograph associated with a gage that HMS produces once the
data is saved.
76
Figure 6-4. Hyetograph.
In the Subbasins section the subbasin names are entered and the number of
gages associated with each subbasin is shown. Subbasins are added from
the basin model by clicking the Add button. The addition of subbasins from a
basin model must be done before the subbasins can be referenced in the
Weights section. Index precipitation (e.g., normal annual) amounts can be
entered for both precipitation gages and subbasins. If such data is entered, it
will be used to apply a bias adjustment to gage precipitation.
The Weights section displays information for a single subbasin at a time. A
droplist allows selection of a subbasin that has previously been specified in
the Subbasins section. Gage ID, type, and associated weight are entered in
the table. When a gage ID field is selected, a drop list appears that shows
the gages previously entered in the Gages Section. The gage type is either
?R? for recording, or ?NR? for non-recording, and is entered automatically.
The Total Storm Gage Weight is applicable to both recording and non-
recording gages, whereas the Temporal Distribution Gage Weight applies
only to recording gages. The weights of each type are normalized to sum to 1
if the entered values do not sum to 1.
77
Weights were assigned using the Thiessen diagram below. It was created in
GIS using CRWR PrePro/Precipitation Gage Weights. First, a point
coverage had to be created similar to the section on flow gages (section
4.1.13). Once created, the eight Precipitation gages were added to the view.
The ArcView script creates a Thiessen Diagram found below. This diagram
shows the sub basins with the eight gage locations and the mid point between
each of the eight points. The visible lines represent the mid-point between
two neighboring gages that are perpendicular to a line that would connect the
two gages. The lines between all neighboring gages connect to form
polygons, which represent the areas to which each rain gages contributes
precipitation. Each polygon contains a basin or a portion of the basin. Where
polygon boundaries contain an entire basin, the assigned weight is 1
representing 100% of the basin precipitation is applied by that gage. Bisected
basins are assigned weights depending on the percentage of the basin area
that each gage contributes to. Below, is the Thiessen Polygon generated in
ArcView. The values in blue were entered in the weights section in the HMS
precipitation model.
78
Figure 6-5. Thiessen Polygon.
6.3 Create Control Specifications.
To create the control specifications, the third component of HMS, click on
Edit/Control Specifications/New in the HMS * PROJECT DEFINITION
window. Write Control in the Control Specs ID and in the Description slots of
the HMS * NEW CONTROL SPECIFICATIONS window and click OK. In the
HMS CONTROL SPECIFICATIONS *SETUP window fill in the blanks as
shown in the figure below with the exception of the time interval which should
be 10 minutes. These dates correspond to the storm the Louisville District
chose to use for model calibration.
79
Figure 6-6. Control Specifications Setup.
6.4 Running a Design Storm for Calibration
To calibrate the derived model, a USGS gage is necessary. For Mill Creek, a
gage at Carthage(03259000) (junction 35 in HMS) was used. The time series
data for the gage was provided by Tim Raines, from the USGS. This data
was entered using Edit/Gage Data/Discharge. In the NEW GAGE RECORD
screen, the name Carthage was given for the gage. Selection of the data
type and units is required when the data will be entered manually. Latitude
and longitude data is not required. Select whether the data will be referenced
in an external DSS file or entered manually.
Once the data is entered for the gage, the graph can be attached to its correct
location in the basin file. At junction 35, the right-click was used and
observed flow was selected. In the next window, the Carthage Gage is
selected. When HMS is run and the results at Junction are viewed, the
observed hydrograph will be present for comparison.
80
To run the design storm for model calibration, the basin model is accessed
from the HMS - SCHEMATIC window. First, Simulate/Run Configuration
must be selected. Then, the components created above must be highlighted
and the Add button selected. In the HMS-SCHEMATIC window, clicking on
Simulate/ Compute <Run 1> will begin the simulation. Once the run is
complete, the HMS Compute window must be closed unless there is an error
? if an error occurs, view the run log. To see the hydrograph at any junction,
watershed or stream, click on the arrow located on the upper-left corner of the
HMS-Schematic window and right-click on the applicable element. In the
pop-up menu, choose View Results/Graph. The following figure is the
hydrograph for the Carthage Gage.
Figure 6-7. Carthage Gage Hydrograph (Velocity 1 m/s).
To calibrate this model, parameters must be identified and isolated. In the
initial basin model, the StreamP.txt file designated initial estimated values for
the velocity and Muskingum X of 1 m/s and 0.2 respectively. In viewing the
gage hydrograph, it is evident from the curves that the observed (red) flow
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and the model (blue) flow are not similar. Both curves indicate a steep climb
to the peak on the approach of the flood wave but the peaks and time of peak
do not correlate.
In choosing the parameters that could be adjusted in calibration, velocity and
Muskingum X were chosen arbitrarily. Muskingum X is a storage constant
and has a range of 0-0.5. It is well known that changing this value slightly has
little to no effect on the flows. The value of 0.2 is pretty common in natural
streams. The only other parameter is the velocity. By using the StreamP.txt
file and manually changing the velocities to 0.5 m/s and 1.5 m/s two more
basin files were created using CRWR PrePro. It is evident from the
hydrograph below that the desired end state is not achieved. At V = 0.5 m/s,
the peak flow drops just below the desired level, but the time of peak moves
to the right which in contrary to the desired effect. It is also apparent that the
shape of the curve is not consistent with the observed data. The rising
portion is characteristic, but the peak and falling portion are not characteristic.
Figure 6-8. Carthage Gage Hydrograph (Velocity 0.5m/s).
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In the second hydrograph, the desired end state is not achieved as well.
Using V = 1.5 m/s the peak is almost 150 cms higher than the observed peak
but the time of peak has moved to the left in the desired direction.
Figure 6-9. Carthage Gage Hydrograph (Velocity 1.5m/s).
83
7 Calibration
All models and their parameters are approximations to reality, as such there
is a general need for calibration or checking with observed data. If data are
not available at the site, this can only be accomplished using a regional
relationship between parameter values and physical characteristics. Records
at nearby basins can be used to recalibrate a relation of this type.
Where flood records are available at a site, one or more model parameters
should be adjusted to give the best possible fit of the calculated and observed
hydrographs for at least one flood. Where two or more parameters are
adjusted, interaction of the value?s frequency occurs, so that different
combinations of parameter values give very similar computed hydrographs for
an observed flood but may give quite different results with design floods of
larger magnitude. It is often desirable to select the values of all but the most
important parameter from physical considerations or by judgment and to
adjust the remaining parameter to give the best fit to the observed data.
Manual trial-and-error adjustment of parameters is often of sufficient accuracy
for practical flood estimation and allows examination of the effects of
changing parameter values. Alternatively, automatic optimization programs,
such as the one found in HEC-HMS can be used (Maidment, 1993). Common
calibration methods include judging the fit of a calculated to an observed
hydrograph and split sample testing.
Various criteria may be used for judging the fit of a calculated to an observed
hydrograph. Common measures are the differences between peak
magnitudes, a measure of overall fit (such as the sum of absolute values), or
squares of the differences between lags or other time measures. The first
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two are the most common and satisfactory. There is no one uniquely correct
criterion, and the choice must be made by judgment, taking into consideration
the objectives of the analysis, noting that use of different criteria will usually
lead to different derived parameter values. Even when a single fitting criterion
is used, parameter values derived from different floods will generally be
different as a result of the data errors and the fact that all models are only
approximations of reality. The possibility of trends in derived values should
always be examined (Maidment, 1993).
If sufficient data are available, it is desirable to use split sample testing. The
model calibrated with about two-thirds of the data is tested by its ability to
reproduce the remaining data, considering the effects of any trends. If the
test results lie within acceptable limits, the data and model are accepted, and
recalibration is carried out using all of the data. If the test results lie outside
acceptable limits, the basic assumptions and data used in the calibration
should be thoroughly checked. If the test results are still outside acceptable
limits, resort must be made to recalibrating with all of the data, but confidence
in the results is then reduced (Maidment, 1993).
7.1 The Original Basin Model
As discussed in the HEC-HMS chapter of this report, the program was run
using the basin model created with CRWR PrePro using common parameters
for watersheds. Using the Carthage USGS Gage Station identified as
(Control), the following hydrograph was generated after the run. The red
curve represents the observed data and the blue curve is the HMS generated
hydrograph. It is evident that the model requires calibration.
85
Figure 7-1. Carthage Gage Hydrograph (Velocity 1 m/s).
Method Flow (ft3/s) Time of Peak
Control 8616.7 0630
Run 1 12218.88 0930
Table 7-1. Run 1 Data Versus Carthage Gage.
7.2 Calibration of the HMS Basin Model
Within a basin model in HMS, there are three sections in which to edit
parameters or to refine the model. The method in which these variables were
defined is found in the chapter dealing with developing a hydrologic model.
The following three areas are defined in the model with the respective
parameters and are discussed below:
1. Loss Rates Soil Conservation Service (SCS) Method
2. Curve Number
3. Initial Abstractions (mm)
4. Percent Impervious Cover (%)
5. Reach Routing
6. Muskingum
7. K (hours)
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8. X-Storage Coefficient
9. n-Number of Sub-reaches
10.Lag
11.Lag time through reach (minutes)
12.Transform SCS
13.Basin Lag Time (minutes)
7.2.1 Loss Rates
Loss Rate adjustments are discussed first because there is little room for
refinement in this area. In the loss rates tab of the basin folder, the
parameters that can be adjusted include Curve Number (CN), Initial Losses,
and Percent Impervious cover. A detailed discussion of how all the Loss Rate
values were derived can be found in Chapter 4. A brief discussion of each
value and how it plays in calibration is found below.
Curve Numbers were initially derived in ArcView and CRWR PrePro using
soils and land cover/land use data. The only way to refine these values is to
use more recent land cover/land use data, which is not currently available at
this time. An initial look reveals that there would be little change because
most of the basin is urbanized and only the northern portions of the basin will
show small changes due to urban sprawl.
The parameter of initial losses was derived in ArcView using the generated
Curve Number grid. Generalized values were initially added to HMS using
transfer tables, but once the basin model was built, the values were adjusted
with the ArcView values. These values were used in Run 1 shown above.
87
Initial values for percent impervious cover were added manually based on
personal observations and Digital Ortho Photos. Throughout the basin, a
majority of the area is urbanized while the remainder is agricultural. The
urban areas were given a value of 60% and the agricultural areas were
assigned a value of 30%. All of these values are adjusted in HMS using the
Loss Rate tab of each basin folder.
7.2.2 Reach Routing
The routing parameters for the basin model were derived in CRWR PrePro
using the capabilities of ArcView and CRWR PrePro. The parameters were
added to the model using transfer tables. These transfer tables have some
parameters that are generalized due to the fact that ArcView is not capable of
generating them with precision. For reach routing, the reach length was
defined by ArcView while the stream velocity (1 m/s) and Muskingum X (0.2)
were defined in the transfer tables.
In this HMS model, the runoff is routed using one of two methods as defined
by CRWR PrePro. The routing method determines the time of travel of the
flood wave through each reach in the HMS model. The particular method to
be used is a function of the stream velocities (V) used and the length of the
flow path (L
S
). As shown below, the L
S
/V value will determine the type of
routing method to use. The term Delta t that the fraction is compared against
is the analysis time step. For this basin model the time-step is 15 minutes. If
the resulting value is less than the time step (15 min), the pure lag equation
(t
lag
) is used. This equation is typically used in shorter reaches, and the units
for the lag time are minutes.
88
Equation 7-1. Pure Lag.
When the resulting value is greater than the time step, the Muskingum
method (K) is used. The units of this equation are hours. In looking at the
two equations, it is readily apparent what variable has the greatest effect on
the outcome due to the fact that the length of flow path, which is calculated in
PrePro, is not subject to change.
Equation 7-2. Muskingum Method.
Velocity is not only important in determining the routing method used, but also
the flood wave time of travel. Knowing this, the next task is to determine the
approximate velocities of the channel in hopes of calibrating the model.
Before looking at the velocities, a more in depth look at the Muskingum
Method is necessary to eliminate two of the parameters that are used in the
method. The two parameters are the number of sub reaches (n) and
Muskingum (X).
The number of sub-reaches is just a method of solving an algorithm numerical
instability issue. The value of (n) is an integer value defined by the equation
below. As a result, this is a parameter that will not be refined for the
89
calibration. If a different time step is used, the value of n must be
recalculated to account for the change. If CRWR PrePro is not used with the
parameter tables, the values of n must be calculated manually and entered in
HEC-HMS accordingly.
1
3
+
???
=
Vt
L
n
Equation 7-3. Number of Subreaches.
The Muskingum method models the storage volume of flooding in a river
channel by a combination of wedge and prism storage. During the advance
of a flood wave, inflow exceeds outflow, producing a wedge of storage.
During the recession flow, outflow exceeds inflow, resulting in a negative
wedge. In addition to this, there is a prism of storage, which is formed by a
volume of constant cross section along the length of prismatic channel. This
is illustrated in the figure below (Maidment, 1993).
Figure 7-2. Channel Storage. Source Tate 1998.
The Muskingum X (storage constant) ranges from 0 to 0.5 with the mean near
0.2. For this model, the mean was used for calibration purposes and the
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value was not changed because results are relatively insensitive to the
changing of this value (Maidment, 1993).
To refine the routing method for calibration, the stream velocity is the only
parameter that will need to be considered. A simple sensitivity test was
conducted to see the effects of lower and higher velocities. Using two new
parameter tables with velocities of 0.5 and 1.5 m/s, the following results were
found at the Carthage gage.
Control V=0.5 m/s V=1.0 m/s V=1.5 m/s
Flow (ft3/s) 8616.8 8193.0 12218.9 13560.8
Qdelta vs. Control -423.8 3602.1 4944.1
Peak (24-hr) 6:30 11:00 9:30 9:00
TpDelta vs. Control 4:30 3:00 2:30
Velocity vs. Peak Flow and Time of Peak
0
2000
4000
6000
8000
10000
12000
14000
C o nt ro l V =0 .5 m/ s V =1 .0 m/ s V =1 .5 m/ s
Stream Velocity
F
l
o
w
(c
fs
)
0:00
1:12
2:24
3:36
4:48
6:00
7:12
8:24
9:36
10:48
12:00
Ti
m
e
(
2
4
-
hour
)
Peak Flow Time of Peak
Figure 7-3. Velocity Effects on Flow and Time of Peak.
It is apparent from the graph above, that as the stream velocity increases, the
flows increase while the time of peak decreases. This graph does show that
the flows and time of peak discharge are sensitive to the stream velocities.
In the parameter tables, the velocities are entered as constant throughout the
entire model. It is rather obvious that velocities vary in streams due to the
varying physical characteristics of the channel and floodplain. The following
photos show some of those aspects affecting stream velocity. Mill Creek has
91
sections of concrete lined channel, improved natural channel and numerous
bridges. Due to poor maintenance, sediment has deposited in these
channels as well.
Figure 7-4. Channel Characteristics.
Figure 7-5. Channel Characteristics.
All of these characteristics affect stream velocity. The easiest way to depict
this is using Manning?s equation for English units as shown below.
3
2
3
2
49.1
f
SR
n
V =
Equation 7-4. Mannings.
The variable in the equation are the Manning roughness coefficient (n),
hydraulic radius (R), and the friction slope (S
f
). When viewing the results in a
portion of a channel where the hydraulic radius and slope remain constant, it
92
is apparent that the velocity is sensitive to the roughness coefficient. This is
illustrated below using the various values for (n).
Width= 200 P= 210
Depth= 5 Slope=0.03
Roughness Velocity
Coef (ft/s)
0.012 6.09 Concrete
0.02 3.65 Gravel w/conc sides
0.033 2.21 Gravel w/riprap sides
0.03 2.44 Clean Natural
0.05 1.46 Winding w/weeds
Table 7-2 . Effect of Manning?s n on Stream Velocity.
Manning's n and Velocity
0
2
4
6
8
0 0.02 0.04 0.06
Mannings n
V
e
l
o
ci
ty
(f/
s)
Figure 7-6. Effect of Manning?s n on Stream Velocity.
Velocities vary from 1.4 f/s to 6.0 f/s depending on the channel type. This
change in velocities is indicative of the range within the Mill Creek Basin as
the flood wave passes through the different sections that are natural or
altered.
Cross section characteristics can be found in HEC-RAS when provided with a
geometry file. A table can be generated in RAS when specifying the
parameters required. In this case, all of the variables applicable to the
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Manning?s equation were generated and put into an Excel spreadsheet. This
spreadsheet can be found in Appendix E. Then the series of cross sections
that make up each reach in HMS were grouped accordingly to determine
average values for that reach. An extract of that product is shown below.
The reaches are numbered according to the HMS basin they pass through
numbered from 102 to 129. First all the variables in the Manning?s Equation
were averaged and then applied to the equation to yield an average velocity
for each reach. These values are shown below in column 1 (Velocity of
Averages). Then, Manning?s equation was applied to each cross section in
the reach and the resulting velocities were averaged. These values are
shown below in column 3 (Average of Velocities). Note the term RAS in the
source row, this means that the slopes used in the velocity determination
were derived from the generated RAS data.
Source RAS ArcView RAS ArcView
Velocity Velocity Average Average
of of ofof
Averages Averages Velocities Velocities
Basin Velocity Velocity Velocity Velocity
(HMS) (ft/s) (ft/s) (ft/s) (ft/s)
102 0.92 1.48 1.13 1.85
105 0.69 2.90 0.53 2.92
109 1.77 3.18 1.71 3.56
115 3.88 6.04 3.66 6.35
119 4.27 6.92 3.82 7.19
121 3.97 4.73 3.71 5.16
122 4.08 6.34 3.89 6.81
125 10.35 8.28 9.38 10.11
126 4.10 5.36 5.09 7.17
128 13.60 17.63 13.67 19.44
127 5.30 14.20 5.29 14.73
129 11.17 15.77 8.81 21.51
Table 7-3. Basin Velocity Calculation.
In RAS the slope (S
f
) is determined by the using the channel bottom between
adjacent cross sections. If there is a long distance between two cross
94
sections this slope may no be indicative of the actual slope. In columns 2 and
4 the same procedure of averages was used as discussed above with the
exception of the slope value. Using ArcView, reach slopes were determined
and used to see if there was any difference. The average of velocities
method (columns 3 and 4) appeared to yield data with the smallest deviation.
The slopes in ArcView also revealed more realistic velocities that would be
representative of the channel. As a result, the column 4 values were used to
compare results. The graph below shows the velocity profiles for the various
methods in the 4 columns above. There is a definite trend in the rise and fall
of the velocity as the flood wave moves down the channel.
Stream Velocities
0
5
10
15
20
25
102 105 109 115 119 121 122 125 126 128 127 129
Basins Upstream to Downstream
V
e
l
o
c
i
t
y
(f
t/
s
)
RAS Velocity of
A ver ag es V elo cit y (f t / s)
ArcView Velocity of
A ver ag es V elo cit y (f t / s)
RAS Average of
Velocities Velocity (ft/s)
ArcView Averageof
Velocities Velocity (ft/s)
RAS Generated Velocit ies
Velocity(ft/s)
Figure 7-7. Velocity Profile Using Manning?s Equation.
Geometry data was not provided for all of the tributaries contributing to Mill
Creek. Data was provided for the West Fork branch and to simplify things,
the RAS velocities were used. This average velocity of approximately 5 f/s
was used for all branches and the respective routing methods were
determined. The complete spreadsheet of routing methods can be found in
Appendix C.
The velocities in column 4 were used to attempt to calibrate the model with
the exception of the value for basin 129. The velocity used in Basin 129 was
the value in column 2. As stated above, 5 f/s was used for all tributaries and
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the HMS reach parameters were recalculated in Excel and entered in HMS.
The following is the new hydrograph produced at the Carthage Gage.
Figure 7-8. Hydrograph at Carthage Gage with Adjusted Velocities.
Method Flow (ft3/s) Time of Peak
Control 8616.7 0630
Adjusted Velocities
SCS Lag Equation
With initial Losses
Average % Impervious Cover
19785 0830
Adjusted Velocities
SCS Lag Equation
With initial Losses
0 % Impervious Cover
17902 0845
Adjusted Velocities
SCS Lag Equation
With initial Losses
75 % Impervious Cover
20503 0830
Table 7-4. Impervious Cover Sensitivity Analysis.
The resulting discharge from velocity calibration increased considerably from
the first run. These results are contrary to the desired results for calibration,
but this step is necessary and more representative of actual channel
conditions. Given the fact that the new channel velocities are not enough to
calibrate the model, other parameters must be considered. The table above
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shows the same run of the basin model changing the percent of impervious
cover. A simple tolerance test showing the effects of increased and
decreased impervious cover showed that the adjustment of this variable has
minimal effect.
7.2.3 Transform: Soil Conservation Service (SCS)
The sub-basin lag-time is calculated with the SCS formula and is given below.
In the formula, ( t
p
) is in minutes and is the basin lag time, which is measured
from the centroid of the hyetograph to the peak time of the hydrograph. Other
parameters are the longest flow path (L
w
), slope of the longest flow path (S),
and Curve Number (CN). All of these values are found in CRWR PrePro and
transferred to HMS.
[]
?
?
?
?
?
?
?
?
= t
S
CNL
p
0.8
w
t 5.3,
67.31
9)/1000(
max
5.0
7.0
Equation 7-5. SCS Lag-time.
The only parameter that can be adjusted is the CN, but as discussed above,
recent Land Cover/Land Use data is not available. In addition, due to the fact
that the basin is predominately urban, the increase will be minimal because
max development of the area has peaked.
7.3 Additional Basin Characteristics Contributing to Hydrograph
Changes
Thus far, a simplistic approach has been taken to adjust the parameters in an
attempt to calibrate the model. The main parameter was the reach velocities
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that affect the time of travel of the flood wave. The results still yield peak
flows that are too high with a time of peak that is still late.
A closer look at the basin must be taken to account for some of the oddities
that are characteristic of a heavily urbanized basin in an older city such as
Cincinnati. Below are some of the characteristics that contribute to its
complexity as found on the ORSANCO website
(http://www.orsanco.org/wwdemo/wwd_trib.html). This site is broken into two
sections, one is Land Use and the other is Combined Sewer Overflows
(CSOs). The Land Use information is to reiterate the extent to which the
basin is urbanized. The CSO facts appear to make the model calibration
difficult. A more detailed discussion of CSOs follows.
1. Land Use: Predominately urbanized (Cincinnati Municipal Sewer
District, 1994)
a. residential 46%
b. commercial 13%
c. undeveloped 12%
d. industrial 11%
e. public and recreational 10%
f. agriculture 8%
2. Two reservoirs associated with Hamilton County Park District
a. Sharon Lake: 36 acres
b. Winton Lake: 188 acres
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3. Population - 453,800 (2,130 people/sq. mile)
4. Combined Sewer Overflows (CSO): 57 on the Mill Creek; 45 on Mill
Creek tributaries. The red circles in the diagram below represent the
approximate locations of the CSO outfalls.
Figure 7-9. CSO Locations. Source: http://www.orsanco.org/wwdemo.html.
A combined sewer carries both sanitary wastewater and storm water runoff.
The characteristics of wastewater in a combined sewer will vary depending
upon dry and wet weather conditions and characteristics of surface runoff.
The impact upon wastewater treatment facilities and receiving water may be
significant during wet weather conditions (Qasim, 1999).
On normal days, the combined sewers carry all of Cincinnati's wastewater
through one of the Metropolitan Sewer District (MSD) treatment plants before
99
being released into the Ohio River or one of several creeks and rivers that
feed into the Ohio. But after heavy rains, storm water surges overwhelm the
system's treatment capacity. When flow is too strong, the plants are designed
to allow water to pass by straight into the river
(http://enquirer.com/editions/1998/08/04/loc_river04.html). The diagram
below illustrates how CSOs such as those in the Mill Creek Basin operate.
Figure 7-10. CSO Schematic. Source: http://www.orsanco.org/wwdemo.html.
In looking at the diagram above, one can see that there are two points of
discharge as a result of the CSO system. The overflow drains to the basin
during extreme wet weather conditions. During these times, storm water
runoff as well as raw sewage from the basin runoff. The facility discharges
treated wastewater to stream as well. This creates difficulties in the system
because the overflow discharge is dependent on the time of day and severity
of the storm event. Below is what a CSO outfall looks like in Mill Creek.
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Figure 7-11. CSO Outfall on Mill Creek.
The best way to illustrate what happens with CSOs when it rains is by looking
at a simple diurnal inflow/infiltration curve for a treatment plant. This curve
was taken from Qasim (1999).
CSO inflow/infiltration vs. Precipitation
0
1000
2000
3000
4000
5000
6000
7000
1345 150
0
1615 173
0
1845 200
0
2115 223
0
2345
10
0
21
5
33
0
44
5
60
0
71
5
83
0
94
5
1100 12
15
1330 1445 16
00
1715 18
30
1945 21
00
2215 23
30
Time (15-16 April 1998)
Flow
(
c
f
s
)
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
De
pt
h
(
in)
Mean Dry Weather Flow
Curve
Mean Wet Weather Flow
Curve
Precipitation Depths
Figure 7-12. Inflow/Inflitration Curve with Precipitation.
101
This sample inflow/infiltration curve shows the diurnal effects of wastewater
flows for a typical treatment plant. This is for wastewater only and does not
consider the effects of how a combined system works. Two curves depict the
dry weather flows and wet weather flows. The wet weather flows increase
into the treatment facility as a result of infiltration into the sewer lines.
Considering how a combined system works, it is likely that the wet weather
flows will increase because storm water is routed through the same
conveyance system. During dry conditions, the treatment facility flows peak
around 1000 hours as a result of the morning ?first flush? created by morning
showers and toilet usage.
Assuming the above curve represents a combined system during dry periods,
the facility probably reaches peak storage capacity at 1000 hours as a result
of diurnal flows. The wet weather curve will fluctuate as a result of
precipitation events depending on time, duration, and intensity. For an event
that began the evening before when the facility is at the lowest inflow, the
facility would capture the storm water and treat it accordingly. If the event
occurred in the early morning hours during the rise of wastewater flows, the
plant will reach peak capacity earlier than 1000 hours. When this early peak
occurs, the continuing flows of wastewater and storm water will then overflow
the combined system and discharge to the nearby stream. In this case, the
flows going to the stream can be much greater than would be expected from
the expected runoff. These two examples illustrate how the typical
rainfall/runoff values depicted in HMS may not be indicative of actual
conditions in Mill Creek.
To replicate these conditions in HMS, some simple assumptions must be
made to account for CSO effects. The assumptions are as follows:
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(1) Precipitation occurring prior to the facility reaching full capacity will
be captured.
(2) Precipitation occurring during and after the facility reaching full
capacity will overflow the combined sewer with raw wastewater.
(3) Periods of extended precipitation will cause the treatment facility to
reach capacity earlier than the diurnal dry weather flows.
These assumptions can be visualized plotting precipitation data on the
inflow/infiltration curve as seen above. The above precipitation data was
taken from one of the rain gages in the Mill Creek Basin. In this example, a
majority of the precipitation occurs during early morning hours prior to the
introduction of wastewater flows shown in the rising portion of the curve.
Theoretically, some of the precipitation would be captured by the treatment
facility and the actual peak would occur sooner than 1000 hours. These
assumptions can be validated with Figure 4-44 below.
This is the actual flow data for the Mill Creek Wastewater Treatment Plant on
the 15
th
and 16
th
of April 1998. The red squares indicate the time when the
plant reached capacity and overflow began. The time frame is 0103 hours to
1101 hours on 16 April. This is due to the rainfall that occurred in the early
evening. From 0000 hours to 0200 hours, 1.26 inches of rain fell on the basin
around the Mill Creek WWTP. Remembering how diurnal municipal wastes
flow, the plant should have been at its lowest flow period during dry weather.
The reason it peaked was the capture of the runoff from the 1.26 inches that
fell and was captured by the combined sewers. This lends validity to the
assumptions made above.
103
Mill Creek WWTP Flow 15 & 16 April 1998
04/16/1998 1:03
04/16/1998 11:01
0. 0
50. 0
100.0
150.0
200. 0
250. 0
300. 0
350. 0
400. 0
450. 0
Time (24-hour)
Fl
ow
(M
G
D
)
Figure 7-13. Mill Creek WWTP Flow Data on 15 and 16 April 1998.
During this 10-hour time frame when the plant reached capacity, the inflow
was 398 MGD. The plant design capacity is 130 MGD for the municipal flow.
The fact that the plant was able to accept 398 MGD shows that there is a
significant storage capacity in the plant. Over a 12-hour period this storage
capacity translates to 135 million gallons. In addition to this storage capacity,
there is additional storage in the interceptor pipes. Rough estimates from
Mike Heitz show that the interceptors are about 12 feet in diameter and run in
excess of 30 miles. There are two such interceptors along Mill Creek.
Keeping in mind how the combined system works, once the plant reaches
capacity, the interceptors begin to store water until a point in which it flows
over a weir and to an outfall. Calculations reveal that these interceptors with
the dimensions above can hold around an additional 266.6 million gallons.
There is another unknown amount that is stored in the lines bringing water
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and municipal waste to the interceptors. These rough estimates alone show
how a combined sewer systems affects the natural state of a basin.
To get a realistic look at how this works, some data will be necessary. The
treatment facilities in the basin would need to be identified and their location
plotted in ArcView. A coverage of the actual sewer lines and where they
drain from would form a CSO shed that would show what areas are
contributing to each treatment facility. In addition, the time that each facility
peaked during the event used for calibration yields the time that overflow
occurred.
This data is critical to another assumption, which was not considered in the
earlier parameter calibration. In this case, the precipitation model would have
to be adjusted to account for the capture of runoff that went to the treatment
facility. In simplest terms, when the plant reaches capacity, all precipitation
data prior to that time is deleted and assumed to not contribute to stream
flows. The last item needed to conduct a thorough analysis would be the
discharge locations of the plant treated discharges and CSO outfalls. In
some cases, the outfalls may be out of the basin to other water bodies such
as the Ohio River. This translates to a portion of the basin that does not
contribute to Mill Creek Flows.
To verify these assumptions, the HMS model was copied and altered to see
the effects on the hydrograph at the Carthage gage. The following are a
series of runs that were conducted in which a portion of the precipitation data
was removed replicating a time when overflow occurs.
105
Figure 7-14. Hydrograph with Precipitation Beginning at 0200 hours.
Method Flow (ft3/s) Time of Peak
Control 8616.7 0630
Precip 0200 hours 11650 0945
Table 7-5. Results of Adjusted Precipitation at 0200 hours.
Figure 7-15. Hydrograph with Precipitation Beginning at 0300 hours.
Method Flow (ft3/s) Time of Peak
Control 8616.7 0630
Precip 0300 hours 9537.9 1000
Table 7-6. Results of Adjusted Precipitation at 0300 hours.
These runs show how the peak discharge drops dramatically after assuming
that the precipitation in the earlier portion of the event goes straight to the
treatment facility. It appears that this assumption is correct in order to
106
calibrate the peak flows. Though this is generalized throughout the basin,
refined times of when the treatment facilities reached capacity will continue to
bring the flows into tolerance.
The next parameter that needs calibration is the time that the peak discharge
occurs. In both examples above, the flood wave is still over three hours late.
This means that the wave must hit sooner. After having adjusted all of the
possible parameters as discussed earlier another in depth look at the basin is
still required.
This urban environment in littered with conveyance systems to carry
wastewater and storm water. This forces one to look at the method in which
basin lag times were calculated. The SCS Lag equation below uses the
longest flow path of the watershed, the average watershed slope, and the
runoff curve number. The equation was adapted to small urban basins and
found to be generally good where the area is completely paved but tends to
overestimate in mixed basins (Maidment, 501). The fact that it tends to over
estimate reveals that the basin lag times are too long and thus cause the time
of peak to occur later.
[]
?
?
?
?
?
?
?
?
= t
S
CNL
p
0.8
w
t 5.3,
67.31
9)/1000(
max
5.0
7.0
Equation 7-6. SCS Lag-time Using Curve Number.
In considering the makeup of the basin and the numerous conveyance
systems, it appears that in most cases the water runs off pavement to nearby
combined sewers and flows to the treatment plant or creek by way of pipe
flow which is much quicker than the overland flow replicated in the SCS Lag
107
Equation. A more realistic representation would be the longest flow path and
average pipe flow through a combined sewer system.
t
xVx
L
Tp ?= 5.3,
67.160
Equation 7-7. SCS Lag.
Using the basin model that replicated the flows above with the adjusted
precipitation model the lag times were adjusted using the above equation.
The following hydrographs were produced at the Carthage gage.
Figure 7-16. Hydrograph with Precipitation Beginning at 0300 hours and Adjusted Lag
Times.
Method Flow (ft3/s) Time of Peak
Control 8616.7 0630
Precip 0300 hours
L/V Lag time w/ V=1.5 m/s
12,959 0715
Table 7-7. Results of Adjusted Lag Time and Precipitation at 0300 hours.
108
Figure 7-17. Hydrograph with Precipitation Beginning at 0330 hours and Adjusted Lag
Times.
Method Flow (ft3/s) Time of Peak
Control 8616.7 0630
Precip 0330 hours
L/V Lag time w/ V=1.5 m/s
10,107 0730
Table 7-8. Results of Adjusted Precipitation at 0330 hours.
The results above show how the adjusting of basin lag times brings the time
of peak within one hour of the actual time and the flows within 1500 cfs
verifying the assumptions made about the effects of the combined sewer
system. Given more detailed information about the treatments facilities within
the basin, this model can be calibrated to this particular storm event. This
requires a great deal of work due to the complexities of the basin and the
effects of wet weather on the sewer system.
The problem that arises from the calibration of this system is the calibrated
model cannot be used to replicate the frequency events necessary for
planning flood control measures. This model is calibrated to a particular
event, and the precipitation model is adjusted using assumptions about how
much runoff is actually flowing to the river and how much is captured for
109
treatment. A worst-case method will have to be established for planning
purposes in order to use this model for flood control planning.
110
8 Hydraulic Modeling with HEC-RAS
This chapter details the application of Hydraulic Modeling with HEC-RAS.
Figure 8-1. Hydraulic Modeling with HEC-RAS.
8.1 Data Requirements.
The data required for this section is the output time series data from the HMS
model in the previous section titled, MillCreek_CSO_lag2.dss. Additional
requirements are the cross section geometry data titled Mill Creek, Upstream
at Barrier Dam; Mill Creek, Middle Sections; West Fork Mill Creek; and Mill
Creek in Hamilton County. The Louisville Corps of Engineer District provided
this information. With a working directory selected, these files were
downloaded for use.
111
8.2 Starting the Project
HEC-RAS is started by clicking, Start/Programs/Hec/HEC-RAS 2.2.The
following window (Main Project Window) will subsequently appear.
Figure 8-2. RAS Program Screen.
A Project in RAS refers to all of the data sets associated with a particular river
system. To define a new project, File/New Project is selected to bring up the
main project window.
Figure 8-3. New Project Window.
The working directory in this case was set to C:\xsections where the geometry
data provided by the Louisville District was stored. The title ?Combined Cross
112
Sections? was designated in the title block and the file name was Mcomb.prj.
All project filenames for HEC-RAS are assigned the extension ".prj".
After clicking the OK button, a window opens confirming the information just
entered. Click the OK button. The project line in the main project window will
now be filled in. The Project Description line at the bottom of the main
project window allows a detailed name for the actual short Project name. If
desired, the button to the right of the Description barcanbeclickedfor
additional space to type a lengthy description.
Each HEC-RAS project requires three components - Geometry Data, Flow
Data, and Plan Data. The Geometry Data consists of a description of the size,
shape, and connectivity of stream cross-sections. The Flow Data contains
discharge rates, and the Plan Data contains information pertinent to the run
specifications of the model, including a description of the flow regime. Each
of these components is discussed in detail below.
8.3 Importing and Editing Geometric Data
The first of the components considered is channel geometry. To analyze
stream flow, HEC-RAS represents a stream channel and floodplain as a
series of cross-sections along the channel. To create a geometric model of
Mill Creek it is necessary to import the geometry files provided by the
Louisville District. In HEC-RAS main project window, select File/Import
HEC-RAS Data and the most downstream set of cross-sections
(millcrk2.g01). This HEC-RAS geometry file contains physical parameters
describing Mill Creek cross-sections. To view the data, select Edit/Geometric
Data from the project window.
113
Figure 8-4. Geometric Data for Lower Portion of Mill Creek.
To complete the main channel, the remainder of the cross-sections must be
added to the current set. Select File/Import Geometry Data/HEC-RAS
Format; then select the radio button stating add data to current geometry.
In the next view, select the geometry file for the cross-sections upstream titled
?Middle Sections; West Fork Mill Creek.? The Geometric Data View will show
the added cross-sections. The same process is used for the final set titled
?Creek in Hamilton County.? The following figure will be in the view that
contains all of the cross-sections.
114
Figure 8-5. RAS Geometric Data.
The tick marks and corresponding station numbers denote individual cross-
sections. Choices under the View menu provide for zoom and pan tools.
The six buttons on the left side of the screen are used to input and edit
geometric data. The River Reach and Junct buttons are used to create the
reach schematic. (A reach is simply a subsection of a river, and a junction
occurs at the confluence of two rivers.) Since the reach schematic is already
defined, there is no need to use these buttons.
The Cross Section, Brdg/Culv, and Incline Weir Spillway buttons are used
to input and edit geometric descriptions for cross-sections and hydraulic
structures such as bridges, culverts, and weirs. The View Picture allows
association of an image file (photograph) with a particular cross-section. Click
on the Cross Section button to open the cross-section data window.
115
Figure 8-6. RAS Cross Section Data.
The data used to describe the cross-sections include the river station/cross-
section number 236431 in the figure, lateral and elevation coordinates for
each terrain point (station and elevation columns), Manning's roughness
coefficients (n), reach lengths between adjacent cross-sections, left and right
bank station, and channel contraction and expansion coefficients. This data is
typically obtained by field surveys. The up and down arrow buttons can be
used to toggle between different cross-sections. Data is edited by double-
clicking on the field of interest and manually changing the value. When
performing this action, all of the data fields turn red and the "Apply Data"
116
button is enabled. Input data colored red indicates that the application is in
edit mode. To leave edit mode:
1.Click the Apply Data button. The data fields will turn black, indicating that
one is out of edit mode, and the data changes are applied.
2.Select Edit/Undo Editing. This allows users to leave the edit mode without
changing any of the data.
To actually see what the cross-sections look like, select the Plot/Plot Cross-
Section menu item.
Figure 8-7. RAS Cross Section.
The cross-section points appear black and bank stations are denoted with
red. Manning roughness coefficients appear across the top of the plot. The
117
up and down arrow buttons can be used to maneuver between different
cross-sections. Any solid black areas occurring in a cross-section represent
blocked obstructions. These are areas in the cross-section through which no
flow can occur. Some cross-sections contain green arrows and gray areas.
This symbolism is indicative of the presence of a bridge or culvert. Input data
and plots specifically associated with bridges and culverts can be accessed
from the main geometric data editor window by clicking on the Brdg/Culv
button.
8.4 Importing and Editing Flow Data
To enter the flow editor, Edit/Steady Flow Data is selected from the main
project window. At this point, stream flow output from the HEC-HMS model
run in the HMS section is used. The resulting flows are based on the 10-year
design storm taken from the Rainfall Frequency Atlas of the Midwest.
Output data from HEC-HMS models are stored in files with a .dss extension.
DSS stands for Data Storage System, which is essentially a database for
storing time-series information. To use these data, File/Set Locations for
DSS Connections is selected from the main flow data window. To open the
DSS file, File Folder Button is accessed and the MillCreek_CSO_lag2.dss file
is selected from the working directory. The window should now look like this.
118
Figure 8-8. Set Locations for DSS Connections.
The DSS data are stored in table records, each one representing a 24-hour
increment of time-series flow data. Each record is described by several
parameters; some are shown below.
Column Description
A ??????
B HMS hydrologic element (subbasin, junctions, etc.) identifier
C Flow Type (baseflow, floodflow)
119
DDate
E Model Time Step
FHMSRunID
Table 8-1. DSS Data Records.
HEC-RAS allows one to view the hydrograph of any DSS record. The highest
flows for this model run occur on 12 December. After selecting a record with
Column C = FLOW and Column D = 12DEC1999, Plot Selected Pathname
is selected to yield the associated hydrograph shown below.
Figure 8-9. DSS Plot.
The coordinates of the cursor (time, flow rate) are displayed in the bottom
right corner of the plot. The Options/Grid menu item can be selected to plot
gridlines.
120
ReturningtotheSet Locations for DSS Connections window, the HEC-
RAS cross-sections can be linked with their calculated DSS flows from HEC-
HMS. The following table shows the relationship between the junctions in the
HEC-HMS basin model and cross-sections in the HEC-RAS geometry file.
HEC-HMS Basin Outlet HEC-RAS Cross-Section
102 223245
105 219460
109 198820
115 183710
119 176850
121 167500
122 (Confluence with West Fork) 161750
125 154880
126 142190
128 129015
127 121130
129 (Barier Dam) 102400
Table 8-2. HMS Basin Links to RAS Cross Sections.
The procedure for linking the DSS records with their associated cross-
sections is as follows.
121
1.Choose the river station from the drop-down list
2.Click on the button "Add selected location to table"
3.Click on the DSS record in which the Part B corresponds to the
selected cross-section. Ensure that Part B column reads "FLOW" and
Part C says "12DEC1999". Click on "Select DSS Pathname" to link the
data.
4.Repeat for each of the junctions. Below is the view as one works
through the process. Once complete, select OK to save the
associated links.
122
Table 8-3. Set Locations for DSS Connections.
Once the DSS records for the 12 junctions have been set, the DSS data must
be imported. Returning to the main steady flow data window and selecting
File/DSS Import brings up the following view. The fields are filled out as
shown below.
123
Figure 8-10. Importing DSS Data.
To complete the process, the Import Data button is selected and the flows
from HEC-HMS are imported into the HEC-RAS model.
As discussed earlier, the direct step method uses a known water surface
elevation and several hydraulic parameters to calculate the water surface
elevation at an adjacent cross-section. Assuming that a subcritical flow
regime exists for this model the computations will begin downstream. As
such, the water surface elevation at the downstream boundary must be
known. To establish this value, the Reach Boundary Condition button from
the steady flow data window is selected. This allows one to set the water
surface elevation boundary condition to be set by one of four methods:
1.Known water surface - based on observed data
2.Critical depth - the program will calculate critical depth
3.Normal depth - the program will calculate normal depth
124
4.Rating curve - elevation determined from an existing stage-discharge
relationship curve
In this case, the critical depth option is selected in the Downstream column
as shown below.
Figure 8-11. Steady Flow Boundary Conditions.
Once OK is clicked, the main steady flow window will come up and each of
the junctions will have assigned peak flow values from the HMS DSS output.
For cross-sections falling between HMS junctions, the flow value of the
upstream junction is applied. Note that the most upstream cross-section has
not been assigned a flow value, which is normal. Before running the
program, a number will have to be input but its magnitude is inconsequential
because the computations will proceed from downstream to upstream as is
the case with subcritical flow. A value of 2000 was used in this case. To this
point, all of the required flow parameters are present and the model can be
run. The data is saved using File\Save Flow Data and named 10-year
flows. Finally use File/Exit Flow Data Editor to return to the HEC-RAS
project window.
125
8.5 Executing the Model
Selecting Simulate/ Steady Flow Analysis from the project window brings
up the window below. However, before running the model, a plan definition is
needed. The plan specifies the geometry (Imported Geom 01) and flow files
(10 year flows) to be used in the simulation. To define a plan, File/New Plan is
selected and a plan title and a 12 character short identifier are entered.
Figure 8-12. Steady Flow Analysis Compute Window.
To execute the model, one must ensure that the flow regime radio button is
set to Subcritical before clicking the compute button. The computations are
performed by a FORTRAN program named SNET. Clicking the compute
button starts SNET and opens a DOS window that shows the progress of the
simulation. When the computations are complete, the PROGRAM FINISHED
NORMALLY message appears as shown below.
126
Figure 8-13. DOS Finished ? Steady Flow Analysis.
8.6 Viewing the Results
There are several methods available with which to view HEC-RAS output
including: cross-section profiles, perspective plots, and data tables. From the
project window, select View/Cross-Sections.
127
Figure 8-14. Bridge Cross-Section.
The cross-section view after running the program is similar to the one shown
earlier in the document with the exception that the output view also shows the
elevation of the total energy head line (EG Peak Flows), the water surface
(WS Peak Flows), and critical depth (Crit Peak Flows). As with the cross-
section geometry editor, use the up and down arrows to scroll to other
cross-sections. For a profile of the entire reach, select View/Water Surface
Profiles from the project window.
128
Figure 8-15. Water Surface Profile Plot.
Use the Options/Zoom In menu option, to focus on a particular stretch of
reach to see how the water surface relates to structures in the channel such
as bridges. Other available options for graphical display of output data include
plots of velocity distribution (View/Cross-Sections/Options/Velocity
Distribution) and pseudo 3D plots (View/X-Y-Z Perspective Plots)as
shown below.
129
Figure 8-16. X-Y-Z Perspective Plot.
For hydraulic design, it is often useful to know the calculated values of various
hydraulic parameters. HEC-RAS offers numerous options for tabular output
data display. From the project window, select View/ Cross Section Table.
130
Figure 8-17. Cross Section Output for Bridge Cross-Section.
The resulting table includes a number of hydraulic parameters, including
water surface elevation, head losses, and cross-sectional area. At the bottom
of the window, Errors, Warnings and Notes resulting from the steady flow
computations are shown. Additional tabular output data can be viewed by
selecting View/Profile Table from the main project window. Below is an
example of the output by cross-section.
131
Table 8-4. Profile Output Table.
This data can be copied to the clipboard for use in other applications. Other
formats and data types can be viewed by selecting different tables from the
Standard Tables Menu.
132
9 Floodplain Mapping
This chapter details the application of Floodplain Representation with
Floodmap.
Figure 9-1. Floodplain Mapping.
HEC-RAS models have proven themselves floodplain analysis, but the X-Y-Z
Prospective Plots are not sufficient for floodplain visualization. The following
is a method to quickly post-process HEC-RAS output and provide an avenue
for floodplain visualization and analysis in ArcView GIS. This method can
also be used to develop a terrain model that accounts for the high density of
points that define a channel while a low density of points is used to define the
surrounding terrain. These properties make this single terrain model
applicable for both hydrologic and hydraulic modeling.
133
This section demonstrates automated floodplain mapping using HEC-RAS
and ArcView GIS using the following procedure:
1. Import HEC-RAS output into ArcView.
2. Create a digital stream representation.
3. Combine HEC-RAS and DEM data to develop a three-dimensional
terrain model.
4. Delineate and analyze the HEC-RAS floodplain.
9.1 Data Requirements
The data required for this exercise consists of a HEC-RAS output data file,
ArcView shapefiles, and the Floodmap ArcView project file (Floodmap.apr)
that can be found in Eric Tate?s website as shown in 2.4. A working directory
titles Flood was established and the appropriate files were added to this
location. The Floodmap.apr file was downloaded and the remainder of the
files was copied using the ArcView Data Source Manager.
9.2 Procedure
With ArcView running, the Floodplain Mapping Project (floodmap.apr) is
opened by selecting File/ Open New Project. The working project is now
called floodmap.apr. It is imperative that the working directory be set to the
Flood folder that was created earlier. Within this folder a Tmp folder must be
created in the same manner as earlier ArcView projects. The Flood Mapping
Project is customized with special menu options to help in the floodplain
mapping process. The primary menus of interest are the Floodmap and
Flood-Utility selections, located on the main-menu bar of ArcView.
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A summary description of the Floodmap and Flood-Utility menu items are
provided as follows.
1. Floodmap
? Import HEC-RAS Data - Translates HEC-RAS output data from
text file to ArcView format.
? Format Digital Stream - The digital stream centerline shapefile
must be formatted in order to be used in the subsequent steps.
? Map HEC-RAS Cross-Sections - Map coordinates are assigned
to HEC-RAS cross-sections.
? Resample Cross-Section Elevations - Resamples cross-section
elevations to incorporate digital elevation model (DEM)
elevations data.
? Stream Centerline and Banklines - Forms a three-dimensional
line theme of the stream centerline, right banks, and left banks.
? Convert Grid to Points - Performs a raster to vector conversion
onaDEM.
? Cross-Section Bounding Polygon - Forms a polygon
representing the outer boundary of the mapped cross-sections.
? Map Water Surface Profiles - HEC-RAS computed water
surface profile at each cross-section is assigned map
coordinates.
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? Delineate Floodplain - Areas inundated by flooding are
determined.
2. Flood-Utility
? Flip Polyline - Reverses the direction of a line theme.
? Compare Cross-Section Profiles - Creates a text file containing
cross-section coordinate data that can be used to create profile
plots.
? Clip Grid by Theme - Clips a DEM based on a given polygon
theme.
9.3 Importing HEC-RAS Output
To move into the GIS environment, the HEC-RAS output information must
first be extracted. Once a model is executed in HEC-RAS, an output text file
can be created selecting File/Generate Report from the main project
window. When the selection window comes up, Plan Data and Geometric
Data is selected as the General Input Data, Reach Lengths is selected under
the Summary Input Data, and Cross Section Table is selected under the
Specific Table (Detailed Output) option. Additionally, only one profile is
selected for the report and the modeled stream has only one branch. Only
one branch can be used due to a level of complexity that cannot be currently
handled by the ArcView scripts. If modeling more than one flow profile, the
specific profile used for the output report can be selected using the Set
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Profiles button. The Report Generator window will look somewhat like the
following graphic.
Figure 9-2. Report Generator.
Once the window looks similar to the above figure, click on the Generate
Report button. HEC-RAS will create an output file and save it in the location
designated. The resulting output file can be viewed in any text editor. The
data must then be imported into the ArcView project by selecting
Floodmap/Import HEC-RAS Data. Prior to continuing, the correct units must
be designated. The HEC-RAS model has units of feet, while the GIS data are
in units of meters. When queried by ArcView for the units, meters must be
selected.
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The time to import the data will vary depending on the file size. The progress
is shown at the bottom of the view window. When the processing is
complete, a file name and location must be selected at the prompt. In
actuality what is happening here is the data is being transformed from a text
file format into a dBase format to be read by ArcView.
To view the data in ArcView, the Tables icon must be selected in the main
project window. The table selection window should now show a Table1.
Once opened, the table should appear as below.
Table 9-1. HEC-RAS Imported Cross-section Table.
For each cross-section in the HEC-RAS output file, the following data has
been retrieved and stored.
? Station - cross-section number
? Description - description of the cross-section, if provided in HEC-RAS
? Type - type of hydraulic structure
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? FloodElev - water elevation stored in a global variable, not in the table -
the lateral and elevation coordinates of all cross-section points
? LFloodX, RfloodX - the width of the left and right floodplain as
measured from the stream centerline
? LBankX, RbankX - the distance to the bank stations as measured from
the stream centerline
? LBankZ, ChannelZ, RbankZ - the elevation of the left bank station,
stream center, and right bank station
? ChannelY - the additive reach lengths between cross-sections starting
from the upstream end
9.4 Stream Centerline Representation
The overall goal of mapping HEC-RAS output is to take cross-sectional and
water surface profile data from a one-dimensional model and transform it into
two-dimensional map coordinates. The previous step brought the model data
into ArcView, and a reference system is now needed to assign map
coordinates to these data in geographic space. This reference system is a
GIS representation of the stream centerline. There are four primary sources
from which to obtain a digital representation of the HEC-RAS stream
including:
1. Survey Data - Data representing the stream centerline may be
available from field surveys. If so, this is perhaps the quickest
way to generate a vector GIS representation of the stream.
2. Reach Files - Reach files are a series of national hydrologic
databases, which uniquely identify and interconnect the stream
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segments (reaches) that comprise the nation's surface water
drainage system. The databases include such information as
unique reach codes for each stream segment,
upstream/downstream relationships, and stream names (where
possible). The latest release, reach file 3 (RF3), consists of
attributed 1:100,000 scale digital line graph hydrography. The
data can be downloaded from the U.S. Environmental
Protection Agency (EPA) BASINS website.
3. DEM-Based - A program such as CRWR-PrePro can be used to
derive a vector stream representation using a DEM as the sole
input.
4. Digitize the Stream - Using either a digital orthophotograph or digital
raster graphic (DRG) as base map, the stream can be digitized
using tools in ArcView. DRGs are digitized and geographically
referenced topographic maps.
The RF3 file was used for Mill Creek to create the stream centerline. The
original RF3 file was added to View 1. Using the Select Feature, the main
channel was selected; selecting Theme/Convert to Shapefile created a
single line representation as shown below.
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Figure 9-3. Center Line Representation.
Regardless of the source of the stream centerline, the attribute table of the
shapefile will need to be modified to enable its use in subsequent steps of the
floodplain mapping. To modify the attribute table, the digitized line theme
must be active. Select Floodmap/Format Digital Stream and enter
Centerrf3. It is important to know the direction of the stream line theme.
Although common sense says that it should point upstream to downstream,
HEC-RAS defines streams in the opposite direction. To be consistent with
the HEC-RAS data, the digital stream should point from downstream to
upstream.
To check the direction of the line, double click on the theme in the legend bar
to bring up the legend editor. Click on the pen palette and choose an arrow
representation. In actuality, Mill Creek flows from north to south. In this case,
the digital stream is oriented correctly, from downstream to upstream. If this
wasn't the case, the direction could be reversed by making the theme active
selecting Flood-Utility/Flip Polyline.
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Figure 9-4. Stream Direction.
9.5 Cross-Section Mapping
The first step in assigning map coordinates to the cross-sections is to
compare the reach lengths according to HEC-RAS and their counterparts on
the digital stream centerline. It is possible, for example, that the digital stream
is defined to a point farther upstream than the RAS stream or vice versa.
Hence, it is necessary to delineate the upstream and downstream boundaries
of the RAS stream on the digital stream. Intermediate stream definition points
corresponding to important RAS cross-sections such as bridges or culverts
can also be defined.
To help define the upstream, downstream, and intermediate points, we'll use
a theme of roads in the point delineation process. Add the roads.shp to the
view, and activate the view and select Theme/Auto-label. In the label field,
select Street_nam. The roads theme will now be labeled with the individual
street names. Next, activate Mcwshd.shp in the legend bar, and click on the
Label Points tool. The project is now prepared to start defining points on the
digital stream. The points we will define are as follows.
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Type Station Location
Upstream boundary 231761 Tylersville Road
Intermediate point 212180 Bridge #5
Intermediate point 201935 Bridge #29
Intermediate point 195540 Bridge #25
Intermediate point 194228 Bridge #23
Intermediate point 188635 Bridge #21
Intermediate point 183540 SHARON CREEK
Intermediate point 182205 Bridge #15
Intermediate point 171035 Bridge #10
Intermediate point 164879 Bridge #5
Intermediate point 162615 Bridge #4
Intermediate point 161750 WEST FORK OF MILL CREEK
Intermediate point 156740 Bridge #3
Intermediate point 155808 Bridge #1
Intermediate point 153675 VINE STREET BRIDGE: REDONE BY
Intermediate point 148103 Bridge #10
Intermediate point 146810 Bridge #9
Intermediate point 131835 Bridge #12
Intermediate point 129860 Bridge #11
Intermediate point 122720 LUDLOW VIADUCT
Intermediate point 119235 Bridge #6
Intermediate point 114975 Bridge #5
Intermediate point 109951 Bridge #3 WESTERN HILLS VIADUC
Intermediate point 103608 Bridge #2
Downstream boundar 102618 Bridge #1
Table 9-2. Cross Section Georeferencing.
To begin the process, the intersection of Tylersville Road and Mill Creek was
found and selected. When queried for the type of boundary, Upstream
boundary was chosen. The click of the mouse causes the script attached to
the Label Points tool to determine the nearest point along the stream
centerline and snap the point onto the digital stream. Next the intersection of
Bridge #5 (Station 212180) and Mill Creek was selected and defined as an
intermediate point. The process was continued using the remainder of the
points as shown above from upstream to downstream. The view window
should look as follows.
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Figure 9-5. Stream Definition Points.
The stream definition points will form the backbone of the cross-section
georeferencing process. Using the data table resulting from the data import
step, the HEC-RAS data corresponding to the definition point locations will be
associated with these map coordinates.
To select the relevant HEC-RAS data, return to Table1. Using the Station
and Description columns as a guide, select the records for the designated
stream definition points using the shift key. All of the selected records should
be the ones shown in the table above.
When finished, the Promote tool is used to promote the highlighted records
to the top. The highlighted records should be cross-referenced to ensure that
all of the records are included. Next, select Floodmap/Map HEC-RAS
Cross-Sections in the view window. (Note: It is important that this step is
performed in the same sitting as the data import step. Otherwise, you'll
receive the error message "A(n) nil object does not recognize the request
get." This is due to that fact that many of the cross-section data is stored in
global variables, which are not saved when exiting ArcView.) When queried,
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Bounds.shp is chosen as the stream definition point theme, Centerrf3.shp as
the stream centerline theme, and Table1 as the HEC-RAS geometry table. A
prompt will query the user to choose a distance for calculation of cross-
section orientation. This input window is for a parameter that will determine
the orientation of the cross-section relative to the stream centerline. A value
of 0 will cause each cross-section to be mapped perpendicular to the stream,
at the precise cross-section location. Using a zero value could cause some
cross-sections to intersect near bends in the stream. As the orientation
parameter increases, perpendicularity is determined based on a longer
segment of the stream. For this project the default value of 5 was used.
Figure 9-6. Cross Section Orientation.
The resulting line theme of the HEC-RAS cross-sections should appear like
the graphic shown above.
9.6 Terrain Modeling
Most available digital elevation models, regardless of the resolution, do not
achieve a high level of accuracy or resolution within stream banks. This is due
to the interference of trees and water in point selection during the
photogrammetric process. HEC-RAS is a good source of elevation data
describing the channel, but typically these data do not possess map
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coordinates. Combining the DEM and HEC-RAS data to form an integrated
terrain model enables the data to be used for 3D terrain and floodplain
visualization. The triangular irregular network (TIN) data model is used to
form the integrated terrain model.
Creating a TIN terrain model from two different data sources presents its
challenges: the DEM and HEC-RAS data have different collection times,
methods, and resolutions. The point where the HEC-RAS data ends and the
DEM data begins, called the transition zone, results in elevation differences.
A method to smooth the transition zone is applied. For each cross-section,
between the stream banks and the ends, the elevations are resampled using
elevation values from the DEM. To initiate this process, the 30-meter DEM is
added to the view. Some work on the DEM is necessary because the DEM is
constructed with latitude and longitude measured in meters and elevation
measured in feet. To begin, both the Analysis Extent and Analysis Cell Size
must be set to Same as Mcgridpro using Analysis/Properties. Next the
Map Calculator must be set up selecting Analysis/Map Calculator as
follows.
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Figure 9-7. Map Calculation to Convert Grid Elevation to Meters.
Selecting Evaluate creates a new grid with the elevations in meters. To
begin terrain modeling, Floodmap/Re-Sample Cross-Section Elevations is
selected. When queried, select Terrain3d.shp and Mcgridpro1 as the inputs.
The execution takes a few minutes as the elevation of every cross-section
point outside of the main channel is being recalculated. To help visualize the
result of the cross-section resampling, a tool with which to create three
profiles of any given cross-section has been developed, based on the original
cross-section, the DEM, and the resampled cross-section. Selecting Flood-
Utility/Compare Cross-Section Profiles and the appropriate themes to
profile the cross-section (231761) for comparison. The coordinate data is
written to an ASCII text file that can be plotted using Microsoft Excel. After
saving the text file, open it in Excel with the import wizard. The data can then
be graphed on an x-y scatter plot as found below.
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15
20
25
30
35
40
45
50
55
60
0 5 10 15 20 25 30 35 40 45 50 55 60
Resampled Cross Section
DEM
Figure 9-8. Cross-Section Profile.
The figure above shows two things:
1. The resampled cross-section (in blue) is identical to the original
cross-section between the stream banks. But in the floodway, it
begins to approximate the DEM (Red) as it moves to the end of
the cross-section. This ensures a smooth transition from the
hydraulic data to the DEM data.
2. By looking at the figure, it is easy to see why 30-meter DEM data is
not good enough to use as the basis for hydraulic modeling: the
representation of the stream channel provides little to no detail
when using 30 cells. This is why the DEM (Red) appears so
flat. In the area that the DEM represents, there may be two
cells that represent the channel.
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Next, data must be developed that will serve as TIN breaklines. TIN
breaklines are the three-dimensional stream centerline and banklines.
Breaklines indicate significant terrain features that represent a change in
slope and the TIN triangles do not cross these breaklines. Next
Floodmap/Stream Centerline and Banklines must be selected with
3dxsects.shp as the cross-section line theme.
To create a TIN with ArcView 3D Analyst, the input data must be either raster
or vector, but not both. As a result, a raster to vector conversion must be
conducted on the DEM. To do this, select Floodmap/Convert Grid to
Points.
The terrain TIN will basically be made up of two areas, the area within the
floodplain and the area outside the floodplain. As input for the TIN, the cross-
sections will represent areas within the floodplain, which provides greater
resolution due to channel properties. The DEM points will provide elevations
for the landscape outside the floodplain. A polygon, which bounds the cross-
sections, will be used to delineate the transition zone between the two data
sources. To build the polygon, Floodmap/Cross-Sections Bounding
Polygon is used with 3dxsects.shp as the queried line theme.
The final step before creating the TIN is to eliminate any DEM points falling
within the cross-sections bounding polygon. To identify these points, the
DEM point theme must be intersected with the bounding polygon theme. To
do this, the bounding polygon theme (Boundary.shp) is made active and
highlighted with the Select Feature tool. Next the DEM point theme
(Gridpt.shp) is made active and Theme/Select by Theme is used. The drop-
down lists should look like the following figure and the New Set button
selected.
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Figure 9-9. Select By Theme Window.
Clicking on the Open Theme Table button displays the attribute table of the
DEM point theme. In the table window, select the Promote button needs to
promote the selected DEM points within the floodplain. These points need to
be edited out of the shapefile. Select Table/Start Editing and then the
Edit/Delete Records to eliminate the points. To save the edits, select
Table/Stop Editing. In the view window, the DEM should look like the
following with the points within the floodplain eliminated.
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Figure 9-10. Point Representation of DEM with Floodplain Points Eliminated.
All of the necessary steps are complete to create the terrain TIN. The
following themes must be made active in the legend bar: Stream3D.shp,
3dxsects.shp, and Mcgridpt.shp. Then, selecting Surface/Create TIN from
Features to make the following window appear:
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Figure 9-11. Create New TIN Window.
The theme Stream3d.shp is a three-dimensional line shapefile of the stream
centerline and banklines. These data will be enforced in the TIN as
breaklines. Fill in the window as shown in the graphic. Next, select the
cross-section line theme 3dxsects.shp on the left side of the window. In the
Input as: drop down list, select Mass Points. Finally, select the DEM point
theme Gridpt.shp. Select Mass Points from the Input as: window and
Grid_code as the Height Source. Click on the OK button to create the TIN.
When ArcView has finished processing the data, the TIN theme will appear in
the legend bar. The figure below shows a zoomed in portion of the TIN. The
green portion is the channel of Mill Creek.
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Figure 9-12. TIN of Mill Creek
Notice that there is a smooth transition where the hydraulic data (cross-
sections) meets the DEM data. The Add Theme button, build.shp and
streets.shp can be added to the view to get a perspective of the 2-D
visualization. The figure below shows the same area as above with the
building and roads added.
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Figure 9-13. TIN with Buildings and Streets.
To view the TIN in 3D, View/3D Scene is selected. Prior to doing this, the
buildings and streets shape file must be converted to a 3D format. This is
done by selecting the theme and selecting Theme/Convert to 3D Shapefile.
The files will be renamed Streets3d.shp, and Buld3d.shp. Once this is
complete, View/3d Scene can be selected. The When queried to Add the
View To 3D Scene As: Themes is chosen. When ArcView opens the 3D
theme, it may take a while to present the view. To maneuver in the 3D scene,
click and hold the left mouse button while moving the mouse. The time
required to render the image will depend on the computer's processor speed,
RAM, and video card. The right mouse button can be used to zoom in and
out. The pan tool is enabled when clicking and holding both mouse buttons.
Below are a series of 3D views with the buildings and roads. Initially, the
structures will not have a 3D view. To obtain some perspective, each of the
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themes 3D properties must be adjusted. To do this, select Theme/3D
Properties as shown below.
Figure 9-14. 3D Theme Properties.
Here the building 3D shapefile is assigned a building height of 20 meters.
The reference height of the building?s base is assigned in the Extrude by:
box. Here the buildings are added to the base height of the TIN, more
commonly known as the ground surface. The same procedure is done for the
Streets3d.shp file. The only exception is setting the height to 2 meters
instead of 20-meters as was the case with the buildings. Once the OK button
is clicked, the following can be viewed after maneuvering around the 3D
View.
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Figure 9-15. 3D View of Mill Creek.
In the view above several structures can be seen. General Electric is the set
of buildings in the upper left of the view, in the center to the west of Mill Creek
is Formica Corporation. Residential areas are also shown in the view.
Figure 9-16. Representation of Mill Creek with Buildings set to 20 meter Height.
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The two views below show how other shapefiles can be added to improve the
3D visualization effect. Shown in red are the levees that many of the private
industries have constructed to protect themselves from flooding. The levees
were added in a similar manner as the buildings and roads but were given a
height of 6 meters for effect.
Figure 9-17. 3D View with Levees Added.
In the view above, Ford Motor Company is in the top right with Astro
Containers just south. As Mill Creek winds, another levee can be seen
protecting Ashland Chemical which sits right next to the creek and Sysco
which makes up the series of building to the west of Ashland Chemical.
Another levee is visible in the bottom left just below Sysco. The view below
shows a view from west to east of Ford Motor Company with its protecting
levees.
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Figure 9-18. 3D View of Ford Motor Company and its Levees for Protection.
Now a TIN is built that depicts the general landscape and has additional detail
in the stream channel and floodplain. The density of points within the channel
is sufficient for hydraulic modeling.
9.7 Floodplain Delineation
Areas inundated by flooding occur wherever the elevation of the floodwater
exceeds that of the land. To delineate these areas, we'll create surface
models of the floodwater and land surface, and then compare the elevations.
Let's start with the floodwater model. HEC-RAS represents the floodplain as
a computed water surface elevation at each cross-section. During the data
import step, these elevations were brought into ArcView, along with the
distance from the stream centerline to the left and right floodplain boundaries.
Hence, two things are known about the floodplain at each cross-section:
water surface elevation and width on each side of the centerline.
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Select Floodmap/Map Water Surface Profiles to map the water surface
info. The data inputs are the original cross-section line theme
("Terrain3d.shp") and the HEC-RAS geometry table ("Table1").
The water surface line theme can be used to create a TIN model of the
floodwater surface. Providing that the HEC-RAS model was set up correctly,
the water surface extent will not exceed the cross-section extent. As such,
the cross-section bounding polygon will serve as the outer boundary of the
water surface TIN. Activate the water surface theme ("Water3d.shp") and the
bounding polygon theme ("Boundary.shp") in the legend bar and select
Surface/Create TIN from Features. In the TIN creation window, input the
water surface theme into the TIN as hard breaklines and the bounding
polygon theme as a hard clip polygon; then click OK. The default color
scheme really doesn't look much like floodwater, so if you like, you can load
the legend named "water1.avl." When viewed in a 3D scene in conjunction
with the terrain TIN, flooded areas can be seen as below.
Figure 9-19. 2-D TIN With Water Surface TIN.
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For detailed analysis, the floodplain can be viewed from a planimetric
perspective. In order to be accurate, inundated areas should not be
delineated using the terrain TIN. The HEC-RAS water surface profiles used
to create the water surface TIN were determined using the original cross-
sections and not the resampled cross-sections. Hence, a new TIN of the
surface terrain needs to be constructed.
Activating the themes "Terrain3d.shp", "Stream3d.shp", and "Gridpt.shp" in
the legend bar, select Surface/Create TIN from Features. The parameters
are specified just as in the Terrain Modeling section. When this is complete,
click OK. At this point, delete the resampled cross-section line theme
("3dxsects.shp") and its associated terrain TIN from the view.
Now a TIN model exists for both the land surface and the floodwater.
However, the floodplain delineation is more readily performed using the raster
data model instead of TINs. Convert both TINs to grids and make the land
TIN active. Then select Theme/Convert to Grid. Select landgrid when
prompted for a grid name. In the conversion extent window, set the Output
Grid Extent to be the same as the land TIN, Output Grid Cell Size to "As
Specified Below," and input the cell size as 1 meter as shown below.
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Figure 9-20. TIN to Grid Conversion Extent.
Selecting OK will convert the TIN to a 1-meter resolution grid. The same
must be done for the water surface TIN by naming the grid watergrid and
setting the Output Grid Extent to be the same as the water surface TIN. Both
surfaces are now represented as grids. Before comparing the two grids,
define the analysis extent. Select Analysis/Properties and set the Analysis
Extent to Same as Watergrid, the Analysis Cell Size "As Specified Below" and
input it as 1 meter. Select Floodmap/Delineate Floodplain and the script
will compare the two grids and create an output grid consisting only of areas
where the floodwater elevation exceeds the land surface elevation. For the
floodplain grid, the color scheme "water2.avl" can be loaded from the legend
editor. Once the color scheme is loaded, the color ramp values may need to
be adjusted in order to get the effect.
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Figure 9-21. 2-D TIN with Floodplain Grid.
The result is a floodplain map, in which the extent of flooding can easily be
compared to structures of interest such as businesses, schools, and homes.
The query tool can be used to query the depth of flooding at any point in the
floodplain.
This floodplain can be used in a 3-D setting as well. Using the map
calculator, convert the floodplain grid to integer format. Then convert the
floodplain to a 3-D shapefile called floodplain3D.shp. Close the view and
open the 3-D Scene Viewer and add floodplain3D.shp to the view. After
setting the 3-D properties of floodplain3D.shp, the following views are
possible.
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Figure 9-22. Aerial 3-D View with Flooding Effects.
Figure 9-23. Close-up 3-D View of Flooding Effects.
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Figure 9-24. 3-D View of 10-year Rain Event.
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10 Conclusions and Recommendations
The modeling procedures began with ArcView delineating a watershed and
the calculating its hydrologic attributes for use in HEC-HMS. The
uncalibrated flows from HEC-HMS were imported into HEC-RAS for hydraulic
modeling. Finally the HEC-RAS geometry data was imported into ArcView to
create a visual floodplain model. This procedure is intended for the Louisville
Corps of Engineer District?s use as a future endeavor in flood studies. This
chapter discusses the approaches results, advantages and limitations,
potential applications, and suggestions for future research
Figure 10-1. Modeling Procedure.
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10.1 Watershed Characterization with CRWR-Prepro
The Mill Creek Watershed was delineated using the scripts available in
CRWR-PrePro. The ArcView delineated watershed was very similar to the
Louisville District?s hand delineated version in that it was less than 3 square
miles off in total drainage area. PrePro generated basin curve numbers using
Land Cover and Land Use data for use in its generation of a HEC-HMS basin
file with hydraulic attributes. The hydraulic attributes used assumed values
for stream velocities that must be refined in HEC-HMS in order to calibrate
the model correctly. CRWR-PrePro is a quick and efficient tool for
characterizing a watershed.
10.2 Modeling with HEC-HMS
HEC-HMS interfaced well in the basin file created with CRWR-PrePro. This
is attributed to the work done to refine PrePro. The three required
components for HMS were created without incident. The Precipitation Model
required some work to acquire the User Specified Gage Weights. Using
precipitation data from recording gages, ArcView generated a Thiessen
Polygon and the results were entered manually.
Calibration of the model was a lengthy process and was never completed.
Due to the difficulty of calibration, Chapter 7 was dedicated to its discussion.
Numerous attempts were made to calibrate the model against a USGS gage.
The complexity and size of the heavily urbanized basin forced all parameters
to be considered. First, the velocities were refined to replicate the varying
channel properties. The basin lag times were adjusted and curve numbers
were considered. When the hydrograph cold not be calibrated, the effects of
the basins 100 plus combined sewer outfalls were then analyzed.
Assumptions were developed regarding the amount of runoff captured by the
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combined sewer. The assumptions were supported by actual flow data
recorded during the event at the Mill Creek Wastewater Treatment Plant. The
model?s best attempt at calibration was with a combination of assumptions
about basin lag time and the combined sewer effects.
10.3 Modeling with RAS
Time spent modeling with RAS was minimal compared to the other programs.
Creating the RAS model was not a difficult task. The difficulty of the task was
alleviated with the geometry data provided by the Louisville District. The
report generator was used numerous times to extract data needed for
ArcView and HMS. When calibration was abandoned, the best HMS ?Run?
flow data was used in RAS. Once relationships were established with HMS
junctions and corresponding RAS cross-sections, transferring the flow data to
from HMS to RAS was simple. The RAS results could not be analyzed
correctly using the uncalibrated HMS flow data.
10.4 Floodmapping with Floodmap
Floodmapping with the Floodmap.apr project generated some revealing 2-D
and 3-D images. The process of generating the views was rather simple but
it did require some extensive data processing. Creating a TIN using the DEM
and RAS cross-sections resulted in a quality model. The TIN accuracy was
not validated through a spot elevations comparison. Sufficient data was not
available for this comparison. The floodplain delineation was not validated
against digital Q3 flood data that is available through FEMA. Once again, the
calibration problems in HMS do not predict accurate flows for RAS. The
floodplain delineation computation in Floodmap uses this RAS data in its
computations.
167
10.5 Advantages
The methodology used can save time and resources when conducting flood
studies. GIS data is available at numerous websites for downloading.
Providing that the user has some knowledge of GIS operation, the process
can be followed with little difficulty. The generation of this data can allow a
practicing engineer to focus on the results achieved and not the burden of
manual calculations. The procedure allows a quick generation of floodplain
maps that are typically drawn by hand. This task could easily become tedious
if the goal is to evaluate different flow scenarios.
Automated floodplain mapping processes also bring more efficient and
standardized results. Some manual tasks are subjective and the results can
vary. An example of this is the making of a floodplain map that is done by
hand. This task can be accomplished using this process in less time and with
greater accuracy. Its digital format provides for easier updating and data
sharing.
Working in the digital environment allows the user to access any information
in a quicker and more accurate manner. This digital output can usually be
used in other software applications making it versatile as well.
Communicating with individuals and organizations about flood studies can be
difficult. Often proposed projects are cost shared and require additional
support and funding. A method other than a hand generated floodplain map
is needed to communicate the effects of flooding. With the ability to produce
a digital floodplain map, this communication barrier can be alleviated. The
use of 2-D and 3-D representations can be revealing and convincing of
certain effects. Animations are possible as well for visualization purposes.
168
Through animations, time series-data effects can be replicated. Azagra
(1999) demonstrates the capabilities of animations.
10.6 Limitations
The main limitation during the course of this research was the calibration of
the hydrologic model (HEC-HMS). Complicated urban basins require detailed
research in and of themselves. The specifics are discussed in great detail in
Chapter 7.
The digital media is accurate, but the best results are achieved using a TIN
generated from aerial photography in the floodplain. Accuracy is critical to
reliable results. This accuracy is crucial to obtain reliable results; differences
of one foot in the stage height can cause the floodplain to widen. This is
especially true in areas with little relief.
The proposed methodology is still dependent on field data. In order to define
the channel, cross section data must be collected through field surveying. In
the case of this research, this was not an issue as the Louisville district
already had the data collected and in and existing model.
10.7 Applications
There are many applications for this work. Flood control studies rely heavily
on the hydrologic and hydraulic results to make decisions. Often the results
are presented in table form such as those found in RAS. RAS can even
provide an X-Y-Z Perspective Plot that reveals the extent of the floodplain
with given flow conditions. The plot does not show terrain aspects or other
structures that are in the floodplain. Visual floodplains such as those
provided in this document can alleviate some of the mystery and provide
focus for further study.
169
Floodplain modeling results can identify locations in need of remediation. The
view can give a perspective on certain problem areas not seen with other
models. The identified problem areas may help determine the location and
suitability of building certain flood control structures. The best example of this
is trying to identify an area upstream suitable for a detention basin. The
floodplain model with structures will easily assist in this process. Regardless
of the results that the user is seeking, the floodplain model provides focus on
areas that need further research.
The National Flood Insurance Program relies heavily on accurate floodplain
maps. The location of ones home in a floodplain determines the price paid for
flood insurance, especially for those structures located within Special Flood
Hazard Areas. FEMA currently has these maps available on line to assist in
this process.
As technology continues to develop, real-time flood management will be a
reality. This may be accomplished using recording precipitation and flow
gages that beam signals to a controlling station. This data will then be
processed through similar models that reveal upcoming events or effects.
This technology will save lives and allow for the implementation of control
measures.
10.8 Recommendations for Future Work
The purpose of this work was to serve two fold. First, it was to give the
Louisville Corps of Engineer District a perspective on the capabilities of the
applications in this document. This task was accomplished using Mill Creek,
which is currently under study by the Louisville District. This work resulted in
sound results through a systematic and simple process. More importantly,
the work demonstrates the visual capabilities of the applications. As this
170
technology continues to evolve, the ability to apply certain applications will
become easier and more efficient with more accurate results. The second
purpose of this work was to provide the Louisville District with a document
allowing them to capture and utilize the applications. The format of Chapter 4
will help to accomplish this task. It is recommended that the Louisville District
should carry out the procedure described in Chapter 4 and learn from the
results. This will familiarize personnel with the capabilities of the applications
and allow them to use the results to formulate plans or make decisions.
The combined sewer problem identified in Chapter 4 should be reviewed with
the Cincinnati Municipal Sewer District. The combined sewer effects
contribute a great deal to the flooding problems in the basin. A probable
solution is to use ArcView with coverages of the sewer system. This will help
to redefine the hydrologic model in HMS. The natural system has been
altered as a result of the sewer system. ArcView will help redefine the
watersheds that reflect actual conditions. The redefined watersheds and
treatment plant flow data will assist in the calibration of the HMS model. With
accurate flow data, the visual floodplain model will then be effective for
making decisions in flood studies.
171
Appendix A. USGS Gage Data
Carthage Gage
Date Flow (cfs)
04/15/1998 12:00 111
04/15/1998 12:30 111
04/15/1998 13:00 111
04/15/1998 13:30 111
04/15/1998 14:00 113
04/15/1998 14:30 116
04/15/1998 15:00 126
04/15/1998 15:30 146
04/15/1998 16:00 183
04/15/1998 16:30 198
04/15/1998 17:00 221
04/15/1998 17:30 261
04/15/1998 18:00 312
04/15/1998 18:30 312
04/15/1998 19:00 305
04/15/1998 19:30 315
172
04/15/1998 20:00 341
04/15/1998 20:30 371
04/15/1998 21:00 368
04/15/1998 21:30 354
04/15/1998 22:00 336
04/15/1998 22:30 325
04/15/1998 23:00 312
04/15/1998 23:30 300
04/16/1998 0:00 295
04/16/1998 0:30 325
04/16/1998 1:00 515
04/16/1998 1:30 1150
04/16/1998 2:00 2230
04/16/1998 2:30 3780
04/16/1998 3:00 4750
04/16/1998 3:30 5240
04/16/1998 4:00 5520
04/16/1998 4:30 5980
04/16/1998 5:00 7570
173
04/16/1998 5:30 8100
04/16/1998 6:00 8420
04/16/1998 6:30 8620
04/16/1998 7:00 8390
04/16/1998 7:30 7970
04/16/1998 8:00 7360
04/16/1998 8:30 6920
04/16/1998 9:00 6610
04/16/1998 9:30 6410
04/16/1998 10:00 6240
04/16/1998 10:30 6000
04/16/1998 11:00 5840
04/16/1998 11:30 5590
04/16/1998 12:00 5470
04/16/1998 12:30 5340
04/16/1998 13:00 5190
04/16/1998 13:30 5110
174
Carthage Flow Gage
0
2000
4000
6000
8000
10000
04/ 1 5/ 1 998
9:36
04/ 1 5/ 1 998
14:24
04/ 1 5/ 1 998
19:12
04/ 1 6/ 1 998
0:00
04/ 1 6/ 1 998
4:48
04/ 1 6/ 1 998
9:36
04/ 1 6/ 1 998
14:24
04/ 1 6/ 1 998
19:12
Date and Time Group
F
l
o
w
(c
fs
)
175
Appendix B. Recording Precipitation Gages.
Gage Location Date Time Depth (in)
Spring Grove - CWW 15-Apr-98 1345 0.04
1400 0.04
1415 0
1430 0
1445 0.04
1500 0.08
1515 0.04
1530 0
1545 0
1600 0
1615 0
1630 0.04
1645 0.04
1700 0
1715 0
1730 0
176
1745 0
1800 0
1815 0
1830 0
1845 0
1900 0
1915 0
1930 0
1945 0
2000 0
2015 0
2030 0
2045 0
2100 0
2115 0
2130 0
2145 0
2200 0
2215 0
2230 0
177
2245 0
2300 0
2315 0
2330 0
2345 0.08
00
16-Apr-98 15 0.04
30 0.12
45 0.12
100 0.2
115 0.28
130 0.08
145 0.04
200 0.12
215 0
230 0.16
245 0.16
300 0.12
315 0.08
178
330 0.04
345 0.04
400 0.08
415 0.12
430 0.43
445 0.16
500 0.04
515 0.08
530 0.04
545 0
600 0.04
615 0
630 0.04
645 0
700 0.04
715 0.04
730 0.08
745 0.04
800 0
815 0
179
830 0
845 0
900 0
915 0
930 0
945 0
1000 0
1015 0
1030 0
1045 0
1100 0
1115 0
1130 0
1145 0
1200 0
1215 0
1230 0
1245 0
1300 0
1315 0
180
1330 0
1345 0
1400 0
1415 0
1430 0
1445 0
1500 0
1515 0
1530 0
1545 0
1600 0
1615 0
1630 0
1645 0
1700 0
1715 0.04
1730 0.04
1745 0
1800 0
1815 0
181
1830 0
1845 0.04
1900 0
1915 0
1930 0
1945 0
2000 0
2015 0
2030 0
2045 0
2100 0
2115 0
2130 0
2145 0
2200 0
2215 0
2230 0
2245 0
2300 0
2315 0
182
2330 0
2345 0
Total Rainfall (inches) 2.95
183
Gage Location Date Time Depth (in)
Mt. Healthy 15-Apr-98 1445 0.04
1500 0.08
1515 0.08
1530 0
1545 0
1600 0
1615 0
1630 0
1645 0.04
1700 0.04
1715 0
1730 0
1745 0
1800 0
1815 0
1830 0
1845 0
1900 0
184
1915 0
1930 0
1945 0
2000 0
2015 0
2030 0
2045 0
2100 0
2115 0
2130 0
2145 0
2200 0
2215 0
2230 0
2245 0
2300 0
2315 0.04
2330 0
2345 0.12
2400 0.04
185
00
Mt. Healthy 16-Apr-98 15 0.04
30 0.28
45 0.16
100 0.08
115 0.12
130 0.04
145 0.04
200 0.2
215 0.08
230 0.28
245 0.16
300 0.16
315 0.12
330 0.12
345 0.24
400 0.08
415 0.04
430 0.24
186
445 0.08
500 0.04
515 0.08
530 0.04
545 0.04
600 0
615 0
630 0.04
715 0.04
730 0.04
745 0.04
800 0.04
815 0
830 0
845 0
900 0
915 0
930 0
945 0
1000 0
187
1015 0
1030 0
1045 0
1100 0
1115 0
1130 0
1145 0
1200 0
1215 0
1230 0
1245 0
1300 0
1315 0
1330 0
1345 0
1400 0
1415 0
1430 0
1445 0
1500 0
188
1515 0
1530 0
1545 0
1600 0
1615 0
1630 0
1645 0
1700 0
1715 0.04
1730 0
1745 0
1800 0
1815 0
1830 0.04
1845 0.04
Total Rainfall (in) 3.56
189
Gage Location Date Time Depth (in)
Mount Airy Water Tower 15-Apr-98 1445 0.04
1500 0.16
1515 0.04
1645 0.08
2330 0.04
2345 0.08
Mount Airy Water Tower 16-Apr-98 30 0.28
45 0.12
100 0.16
115 0.12
130 0.16
145 0.04
200 0.24
215 0.12
230 0.2
245 0.12
300 0.16
190
315 0.08
330 0.08
345 0.04
400 0.12
415 0.16
430 0.16
445 0.12
500 0.04
515 0.04
530 0.08
615 0.04
645 0.04
715 0.04
730 0.04
745 0.04
800 0.04
1715 0.08
2030 0.08
Total (in) 3.48
191
192
Gage Location Date Time Depth (in)
Brecon Water Tower 15-Apr-98 1445 0.04
1500 0.04
1515 0.08
1530 0.04
1700 0.04
1715 0.08
2345 0.04
2400 0.16
Brecon Water Tower 16-Apr-98 15 0.08
30 0.12
45 0.35
100 0.08
115 0.16
130 0.2
145 0.08
215 0.08
230 0.08
193
245 0.2
300 0.12
315 0.16
330 0.04
345 0.04
400 0.08
415 0.2
430 0.16
445 0.24
500 0.24
515 0.08
530 0.04
545 0.04
600 0.04
630 0.04
715 0.04
730 0.04
745 0.04
815 0.04
1730 0.04
194
2045 0.24
2100 0.08
2115 0.04
Total (in) 4.03
195
Gage Location Date Time Depth (in)
Mill Creek TP 15-Apr-98 2400 0.04
Mill Creek TP 16-Apr-98 30 0.24
100 0.31
115 0.63
200 0.04
230 0.12
245 0.04
330 0.04
400 0.28
415 0.12
430 0.39
445 0.12
515 0.28
530 0.08
600 0.04
615 0.04
645 0.04
196
700 0.04
715 0.04
745 0.04
800 0.04
1730 0.04
1815 0.04
2045 0.04
Total 3.13
197
Gage Location Date Time Depth (in)
Wastewater Collections 15-Apr-98 1445 0.04
1500 0.08
1515 0.08
1700 0.04
2330 0.04
2345 0.04
2400 0.04
Wastewater Collections 16-Apr-98 15 0.04
30 0.08
45 0.12
100 0.16
115 0.16
130 0.08
145 0.04
200 0.12
215 0.04
230 0.08
198
245 0.16
300 0.04
315 0.12
330 0.04
345 0.04
400 0.04
415 0.12
430 0.2
445 0.12
500 0.04
515 0.04
530 0.04
600 0.04
700 0.04
715 0.04
745 0.04
800 0.04
1715 0.04
1730 0.04
1845 0.04
199
2045 0.04
2100 0.04
Total 2.68
200
Gage Location Date Time Depth (in)
Sharonville 15-Apr-98 1445 0.04
1500 0.04
1515 0.16
1700 0.28
1715 0.04
1900 0.04
2345 0.24
2400 0.12
Sharonville 16-Apr-98 15 0.08
30 0.16
45 0.16
100 0.08
115 0.16
130 0.12
145 0.04
200 0.08
215 0.12
201
230 0.04
245 0.24
300 0.12
315 0.24
330 0.08
345 0.08
400 0.12
415 0.35
430 0.2
445 0.35
500 0.12
515 0.08
530 0.04
545 0.04
615 0.04
700 0.04
715 0.04
730 0.04
800 0.04
815 0.04
202
1745 0.04
2045 0.2
2100 0.04
Total (in) 4.58
203
Gage Location Date Time Depth (in)
Deer Park 15-Apr-98 1445 0.04
1500 0.04
1515 0.04
1700 0.04
2330 0.04
2400 0.04
Deer Park 16-Apr-98 30 0.04
100 0.16
115 0.08
130 0.16
145 0.08
200 0.04
230 0.04
315 0.12
415 0.08
430 0.08
204
445 0.16
500 0.08
530 0.04
545 0.04
630 0.04
715 0.04
730 0.04
800 0.04
1830 0.04
Total (in) 1.64
205
Appendix C. Stream Parameters
River Reach Routing Version 2
(hrs) (min)
ARCID LENGTH Vel(ft/s) Vel(m/s) L/V L/V (adj) MUSK
X
ROUTE MUSKK Subreaches LAGTIM
E
TIMESTEP
4 5926.57 1.85 0.56 98.78 175.17 0.20 Musking
um
2.92 2.00 0.00 15.00
6 104.76 2.92 0.89 1.75 1.96 0.20 Lag 1.00 1.96 15.00
9 1186.40 2.92 0.89 19.77 22.22 0.20 Musking
um
0.37 1.00 0.00 15.00
10 104.76 3.55 1.08 1.75 1.61 0.20 Lag 1.00 1.61 15.00
12 38.70 3.55 1.08 0.64 0.60 0.20 Lag 1.00 0.60 15.00
16 6440.26 3.55 1.08 107.34 99.20 0.20 Musking
um
1.65 2.00 0.00 15.00
18 93.43 6.34 1.93 1.56 0.81 0.20 Lag 1.00 0.81 15.00
21 373.71 6.34 1.93 6.23 3.22 0.20 Lag 1.00 3.22 15.00
25 663.39 6.34 1.93 11.06 5.72 0.20 Lag 1.00 5.72 15.00
28 1089.89 6.34 1.93 18.16 9.40 0.20 Lag 1.00 9.40 15.00
38 2053.48 6.34 1.93 34.22 17.71 0.20 Musking
um
0.30 1.00 0.00 15.00
41 104.76 7.18 2.19 1.75 0.80 0.20 Lag 1.00 0.80 15.00
46 797.46 7.18 2.19 13.29 6.07 0.20 Lag 1.00 6.07 15.00
51 1738.39 7.18 2.19 28.97 13.24 0.20 Lag 1.00 13.24 15.00
206
52 154.80 5.15 1.57 2.58 1.64 0.20 Lag 1.00 1.64 15.00
55 325.63 5.15 1.57 5.43 3.46 0.20 Lag 1.00 3.46 15.00
63 2214.11 5.15 1.57 36.90 23.51 0.20 Musking
um
0.39 1.00 0.00 15.00
67 1628.93 6.81 2.08 27.15 13.08 0.20 Lag 1.00 13.08 15.00
69 66.06 6.81 2.08 1.10 0.53 0.20 Lag 1.00 0.53 15.00
68 27.37 10.10 3.08 0.46 0.15 0.20 Lag 1.00 0.15 15.00
76 1795.06 10.10 3.08 29.92 9.72 0.20 Lag 1.00 9.72 15.00
75 1831.82 7.16 2.18 30.53 13.99 0.20 Lag 1.00 13.99 15.00
78 1767.70 7.16 2.18 29.46 13.50 0.20 Lag 1.00 13.50 15.00
79 772.04 7.16 2.18 12.87 5.90 0.20 Lag 1.00 5.90 15.00
81 116.10 19.43 5.92 1.93 0.33 0.20 Lag 1.00 0.33 15.00
82 77.40 19.43 5.92 1.29 0.22 0.20 Lag 1.00 0.22 15.00
85 1036.30 19.43 5.92 17.27 2.92 0.20 Lag 1.00 2.92 15.00
86 834.22 19.43 5.92 13.90 2.35 0.20 Lag 1.00 2.35 15.00
89 1355.28 19.43 5.92 22.59 3.81 0.20 Lag 1.00 3.81 15.00
92 3720.30 14.72 4.49 62.01 13.82 0.20 Lag 1.00 13.82 15.00
94 143.46 15.76 4.80 2.39 0.50 0.20 Lag 1.00 0.50 15.00
96 2837.66 15.76 4.80 47.29 9.85 0.20 Lag 1.00 9.85 15.00
98 2933.44 15.76 4.80 48.89 10.18 0.20 Lag 1.00 10.18 15.00
44353.64
27.72 Miles
207
West Fork
ARCID LENGTH Vel(ft/s) Vel(m/s) L/V L/V (adj) MUSK
X
ROUTE MUSKK Subreaches LAGTIM
E
TIMESTEP
45 2990.85 5.00 1.52 49.85 32.71 0.20 Musking
um
0.55 1.00 0.00 15.00
66 7259.25 5.00 1.52 120.99 79.39 0.20 Musking
um
1.32 1.00 0.00 15.00
South of Sharon
Lake
53 144.18 5.00 1.52 2.40 1.58 0.20 Lag 0.03 1.00 1.58 15.00
56 1646.90 5.00 1.52 27.45 18.01 0.20 Musking
um
0.30 1.00 0.00 15.00
Sharon Lake
30 2665.20 5.00 1.52 44.42 29.15 0.20 Musking
um
0.49 1.00 0.00 15.00
33 915.50 5.00 1.52 15.26 10.01 0.20 Lag 0.00 1.00 10.01 15.00
34 1084.00 5.00 1.52 18.07 11.85 0.20 Lag 0.00 1.00 11.85 15.00
35 93.42 5.00 1.52 1.56 1.02 0.20 Lag 0.00 1.00 1.02 15.00
39 1004.20 5.00 1.52 16.74 10.98 0.20 Lag 0.00 1.00 10.98 15.00
42 104.70 5.00 1.52 1.75 1.15 0.20 Lag 0.00 1.00 1.15 15.00
North of Sharon
Lake
208
20 3718.35 5.00 1.52 61.97 40.66 0.20 Musking
um
0.68 1.00 0.00 15.00
22 104.76 5.00 1.52 1.75 1.15 0.20 Lag 0.02 1.00 1.15 15.00
North Most
8 1602.37 5.00 1.52 26.71 17.52 0.20 Musk 0.29 1.00 0.00 15.00
11 82.09 5.00 1.52 1.37 0.90 0.20 Lag 0.00 1.00 0.90 15.00
209
Appendix D. Watershed Parameters.
Watershed Parameters 12 Mar 1300hrs CN Lag V=1
m/s
V=1.5
m/s
V=1.5m/
s
GRID
CODE
AREA(A) A(KM2) LNG
FLW
PTH
LFP Ft V(m/s
)
V(m/s
)
SLOP
E
slope
%
CN New
CN
LAGTI
ME
New
Lag
(15 m ts) Lag (l/v) LAG=L/V 15*3.5
74.00 17845118.15 17.85 10322.00 33856.15 1.00 1.50 0.01 0.62 87.89 90.00 309.32 284.46 309.21 103.01 103.01 68.68 68.68
73.00 10320979.54 10.32 4858.28 15935.16 1.00 1.50 0.02 1.78 86.68 91.00 105.00 88.12 104.49 48.49 53.00 32.32 53.00
76.00 1615203.72 1.62 2447.92 8029.18 1.00 1.50 0.01 1.44 89.39 90.00 105.00 59.03 60.51 24.43 53.00 16.29 53.00
77.00 3968743.49 3.97 5211.27 17092.97 1.00 1.50 0.01 1.33 89.60 90.00 114.32 112.42 114.28 52.01 53.00 34.67 53.00
79.00 20615750.40 20.62 10360.36 33981.99 1.00 1.50 0.01 1.08 87.68 90.00 236.90 216.17 236.82 103.40 103.40 68.93 68.93
75.00 23137025.75 23.14 10194.24 33437.10 1.00 1.50 0.01 0.83 88.87 91.00 254.84 233.48 254.75 101.74 101.74 67.83 67.83
78.00 9474813.48 9.48 5861.72 19226.43 1.00 1.50 0.01 1.22 88.05 90.00 139.33 128.96 139.28 58.50 58.50 39.00 53.00
80.00 16261364.85 16.26 8136.09 26686.37 1.00 1.50 0.01 0.75 89.58 92.00 217.52 196.37 217.44 81.20 81.20 54.13 54.13
82.00 2851504.76 2.85 3921.28 12861.80 1.00 1.50 0.00 0.21 92.13 93.00 205.86 197.82 205.79 39.13 53.00 26.09 53.00
81.00 13379907.31 13.38 8620.07 28273.83 1.00 1.50 0.01 0.96 90.00 91.00 197.98 189.83 197.91 86.03 86.03 57.35 57.35
83.00 12183293.71 12.18 5488.83 18003.36 1.00 1.50 0.01 1.41 83.60 91.00 144.29 109.16 144.24 54.78 54.78 36.52 53.00
85.00 4360376.11 4.36 4474.41 14676.07 1.00 1.50 0.02 1.89 83.47 91.00 106.30 80.07 106.26 44.65 53.00 29.77 53.00
86.00 746573.07 0.75 2282.95 7488.08 1.00 1.50 0.03 2.68 90.26 91.00 105.00 39.25 40.49 22.78 53.00 15.19 53.00
88.00 23099584.77 23.10 9763.63 32024.70 1.00 1.50 0.01 1.07 88.12 94.00 223.18 173.43 223.10 97.44 97.44 64.96 64.96
89.00 1929707.92 1.93 2321.65 7615.01 1.00 1.50 0.00 0.22 93.56 94.00 123.81 121.21 123.77 23.17 53.00 15.45 53.00
84.00 7812434.13 7.81 6479.81 21253.78 1.00 1.50 0.01 1.25 85.06 94.00 166.44 115.59 166.38 64.67 64.67 43.11 53.00
90.00 7928501.15 7.93 6488.40 21281.96 1.00 1.50 0.01 1.01 88.55 90.00 162.94 153.73 162.88 64.75 64.75 43.17 53.00
91.00 5148883.07 5.15 4850.89 15910.91 1.00 1.50 0.02 1.65 87.00 94.00 107.16 79.81 107.12 48.41 53.00 32.27 53.00
210
92.00 1406283.07 1.41 2526.48 8286.86 1.00 1.50 0.02 2.24 84.73 92.00 105.00 44.58 59.19 25.21 53.00 16.81 53.00
94.00 9687478.22 9.69 7607.63 24953.01 1.00 1.50 0.01 0.56 90.39 91.00 230.79 224.91 230.70 75.92 75.92 50.62 53.00
95.00 11039097.47 11.04 9731.90 31920.63 1.00 1.50 0.01 0.84 87.31 90.00 259.07 233.15 258.98 97.12 97.12 64.75 64.75
93.00 12893923.44 12.89 6238.24 20461.43 1.00 1.50 0.01 1.21 84.48 94.00 167.44 113.97 167.39 62.26 62.26 41.51 53.00
87.00 76821395.29 76.82 17527.32 57489.60 1.00 1.50 0.00 0.44 85.58 90.00 610.59 515.77 610.37 174.92 174.92 116.62 116.62
96.00 12280640.24 12.28 9753.75 31992.30 1.00 1.50 0.01 1.01 85.44 91.00 253.35 204.30 253.26 97.34 97.34 64.90 64.90
97.00 16901605.55 16.90 8077.79 26495.16 1.00 1.50 0.02 1.52 86.49 91.00 171.05 143.22 170.99 80.62 80.62 53.74 53.74
99.00 10751550.77 10.75 7324.51 24024.40 1.00 1.50 0.02 1.66 86.54 90.00 151.05 132.12 150.99 73.10 73.10 48.73 53.00
98.00 42500749.90 42.50 12634.24 41440.31 1.00 1.50 0.01 0.84 87.22 94.00 320.29 240.56 320.18 126.09 126.09 84.06 84.06
100.00 56999393.58 57.00 14603.36 47899.03 1.00 1.50 0.01 0.91 85.27 90.00 370.90 309.92 370.77 145.74 145.74 97.16 97.16
211
Appendix E. Cross Sections and Velocity Refinement.
Vel Vel Avgs Average
of of of of
Avgs Avgs Vel Velocitie
s
River
Sta
Mann
Wtd
Total
Hydr
Radius
Invert
Slope
Arc
View
Vel
Chnl
10.9 V
e
l
Vel Vel Vel Vel Ve
(ft) Slope (ft/s) (ft/s) Arc
View
(ft/s) Arc
View
(ft/s) ArcView
236431 0.06 2.06 0.01 0.01 11.75 3.23 3.33
235781 0.06 0.82 0.00 0.01 6.34 1.32 1.62
234741 0.06 1.59 0.00 0.01 3.67 1.91 2.70
233681 0.06 1.14 0.00 0.01 3.88 0.89 2.33
233161 0.06 0.80 0.00 0.01 3.01 1.33 1.80
232711 0.06 0.96 0.00 0.01 1.76 0.67 2.00
232011 0.05 1.83 0.00 0.01 2.97 2.26 3.50
231811 0.07 2.72 0.00 0.01 2.69 2.18 3.36
231786 Bridge 0.01
231761 0.07 2.71 0.00 0.01 2.92 2.51 3.16
212
231661 0.07 0.74 0.00 0.01 5.06 1.09 1.37
230861 0.08 0.58 0.00 0.01 5.18 0.88 1.01
230061 0.08 1.08 0.00 0.01 2.49 0.62 1.54
229421 0.08 0.84 0.00 0.01 4.46 0.65 1.37
229351 0.07 1.03 0.00 0.01 3.72 0.86 1.81
229350 0.07 1.01 0.00 0.01 3.75 0.85 1.80
229344 Bridge 0.01
229337 0.07 0.99 0.00 0.01 3.84 0.84 1.76
229237 0.07 1.00 0.00 0.01 1.16 0.84 1.78
228927 0.19 1.24 0.00 0.01 2.52 0.47 0.71
228227 0.42 1.11 0.00 0.01 7.87 0.20 0.30
228147 0.07 1.01 0.00 0.01 3.12 1.05 1.59
228131 Bridge 0.01
228115 0.07 0.55 0.00 0.01 5.20 0.66 1.11
227865 0.12 0.69 0.00 0.01 6.95 0.19 0.74
226965 0.08 1.57 0.00 0.01 1.10 0.77 2.03
224365 0.11 2.01 0.00 0.01 1.02 1.01 1.78
223245 0.11 1.94 0.00 0.01 0.88 0.90 1.63
0.09 1.28 0.00 0.01 0.92 1.48 1.13 1.85
222670 0.10 1.53 0.00 0.01 0.98 0.99 2.33
222130 0.09 1.52 0.00 0.01 1.05 0.22 2.55
213
221010 0.09 2.14 0.00 0.01 0.85 0.29 3.32
219460 0.09 2.27 0.00 0.01 1.01 0.61 3.50
0.09 1.87 0.00 0.01 0.69 2.90 0.53 2.92
218948 0.09 2.44 0.00 0.01 1.26 1.77 2.62
218048 0.08 2.10 0.00 0.01 0.90 1.78 2.65
217818 0.11 2.30 0.00 0.01 2.42 1.41 2.10
217778 Bridge 0.01
217738 0.11 2.26 0.00 0.01 2.21 0.97 1.98
216623 0.11 3.20 0.00 0.01 0.77 0.71 2.50
215323 0.14 3.59 0.00 0.01 1.25 0.64 2.25
213690 0.06 3.79 0.00 0.01 0.35 2.30 4.98
212728 0.06 3.04 0.00 0.01 0.50 1.75 4.37
212243 0.09 3.03 0.00 0.01 0.64 1.24 3.10
212193 0.12 4.26 0.00 0.01 0.32 1.15 2.88
212180 Bridge 0.01
212167 0.10 4.23 0.00 0.01 0.62 1.24 3.24
211847 0.07 4.50 0.00 0.01 0.31 1.78 4.87
211527 0.07 4.60 0.00 0.01 0.31 2.81 4.96
210827 0.10 4.15 0.00 0.01 0.44 1.37 3.43
210167 0.14 4.04 0.00 0.01 0.69 0.77 2.35
209427 0.32 3.63 0.00 0.01 2.24 0.25 0.96
214
209027 0.17 3.92 0.00 0.01 1.24 0.55 1.95
208537 0.15 4.92 0.00 0.01 0.86 0.72 2.55
207267 0.08 5.36 0.00 0.01 0.59 0.97 4.87
206919 0.06 5.16 0.00 0.01 0.45 1.35 6.75
206903 Bridge 0.01
206887 0.06 5.15 0.00 0.01 0.31 1.84 6.52
205840 0.09 4.89 0.00 0.01 0.67 1.24 4.37
204970 0.14 4.18 0.00 0.01 1.02 0.67 2.37
203450 0.06 4.05 0.00 0.01 3.69 1.57 5.56
203220 0.12 5.49 0.00 0.01 0.70 0.98 3.46
203015 Bridge 0.01
202810 0.12 5.42 0.00 0.01 0.70 1.98 3.44
202530 0.09 5.06 0.00 0.01 3.61 3.02 4.14
202140 0.10 5.59 0.00 0.01 2.06 1.71 4.11
201950 0.10 5.42 0.00 0.01 1.83 1.64 3.95
201935 Bridge 0.01
201920 0.10 5.41 0.01 0.01 1.84 3.28 3.94
201780 0.12 4.95 0.01 0.01 1.79 2.71 3.25
201680 0.12 5.08 0.00 0.01 1.49 2.41 3.08
201030 0.13 5.23 0.00 0.01 1.23 2.30 2.94
200100 0.08 4.97 0.01 0.01 5.60 6.28 4.75
200070 0.12 5.16 0.01 0.01 1.08 4.11 3.11
215
200055 Bridge 0.01
200040 0.12 5.16 0.00 0.01 1.09 1.08 3.11
199940 0.08 4.74 0.00 0.01 5.90 1.62 4.67
198820 0.14 5.79 0.00 0.01 1.27 1.06 3.06
0.11 4.38 0.00 0.01 1.77 3.18 1.71 3.56
197690 0.13 5.99 0.00 0.01 1.68 1.77 4.00
196730 0.11 6.20 0.00 0.01 2.19 2.02 4.57
196000 0.09 6.21 0.00 0.01 2.83 2.72 6.13
195920 0.06 5.13 0.00 0.01 2.64 3.34 7.53
195910 Bridge 0.01
195900 0.06 5.02 0.00 0.01 2.70 4.99 7.53
195830 0.10 5.41 0.00 0.01 2.87 3.31 5.00
195770 0.10 5.57 0.00 0.01 2.51 3.11 4.70
195710 0.06 4.34 0.00 0.01 2.56 4.85 7.32
195678 Bridge 0.01
195645 0.06 4.33 0.02 0.01 2.56 9.73 7.32
195620 0.06 4.46 0.02 0.01 2.47 9.91 7.46
195610 0.06 4.46 0.02 0.01 2.48 9.91 7.46
195580 0.06 4.46 0.02 0.01 2.48 9.91 7.46
195540 Bridge 0.01
195500 0.06 4.46 0.01 0.01 2.48 7.32 7.46
216
195400 0.06 5.94 0.01 0.01 2.70 8.00 8.15
195325 0.06 5.57 0.01 0.01 2.73 7.66 7.81
195305 Bridge 0.01
195285 0.06 5.42 0.01 0.01 2.80 5.70 7.81
195230 0.06 5.79 0.01 0.01 2.79 5.47 8.00
194865 0.08 5.35 0.00 0.01 1.95 0.79 5.75
194315 0.08 5.39 0.00 0.01 2.22 0.78 5.70
194255 0.06 5.12 0.00 0.01 2.78 0.99 7.27
194228 Bridge 0.01
194200 0.06 5.06 0.01 0.01 2.81 6.54 7.22
194040 0.08 5.69 0.01 0.01 1.95 5.79 6.39
193420 0.08 5.88 0.00 0.01 1.85 2.15 6.70
191920 0.07 5.45 0.00 0.01 1.56 2.18 7.13
191100 0.07 5.81 0.00 0.01 3.50 2.73 7.54
191030 0.08 5.60 0.00 0.01 3.11 2.34 6.47
191023 Bridge 0.01
191015 0.08 5.57 0.00 0.01 3.13 2.33 6.45
190900 0.08 5.14 0.00 0.01 2.13 1.21 5.60
189615 0.07 5.85 0.00 0.01 2.35 1.15 6.86
188750 0.08 5.39 0.00 0.01 3.79 0.94 5.63
188670 0.09 5.43 0.00 0.01 1.64 0.85 5.07
188635 Bridge 0.01
217
188600 0.09 5.41 0.00 0.01 1.65 2.72 5.05
188410 0.08 5.46 0.00 0.01 3.16 1.92 6.29
188000 0.11 6.02 0.00 0.01 2.44 1.87 4.55
187500 0.10 6.01 0.00 0.01 3.64 2.01 4.91
187340 0.06 6.14 0.00 0.01 2.44 3.72 9.06
187330 Bridge 0.01
187320 0.06 6.05 0.00 0.01 2.49 3.01 8.98
187150 0.10 5.81 0.00 0.01 3.78 2.02 4.79
185860 0.13 6.53 0.00 0.01 1.54 2.76 4.20
185270 0.10 6.28 0.00 0.01 3.22 3.58 5.46
185170 0.12 6.74 0.00 0.01 0.85 3.14 4.78
185155 Bridge 0.01
185140 0.12 6.74 0.00 0.01 0.85 1.46 4.78
185040 0.10 6.22 0.00 0.01 3.26 1.66 5.43
184540 0.09 6.28 0.00 0.01 2.02 1.87 5.59
183930 0.09 5.85 0.00 0.01 3.13 2.95 5.57
183800 0.07 5.78 0.00 0.01 2.78 3.70 6.99
183765 Bridge 0.01
183730 0.07 5.67 0.00 0.01 2.84 3.66 6.90
183710 0.08 5.74 0.00 0.01 4.09 3.15 5.94
0.08 5.59 0.00 0.01 3.88 6.04 3.66 6.35
218
183695 0.08 5.73 0.01 0.02 4.09 5.69 7.38
183680 0.06 4.10 0.01 0.02 2.93 6.62 8.60
183655 Bridge 0.02
183630 0.06 4.06 0.01 0.02 3.41 6.69 8.68
183600 0.06 4.07 0.03 0.02 3.40 11.04 8.72
183580 0.06 4.07 0.03 0.02 3.38 10.92 8.72
183555 0.08 4.54 0.03 0.02 3.01 8.76 6.99
183548 Bridge 0.02
183540 0.07 4.40 0.00 0.02 3.10 2.23 6.96
183260 0.10 5.17 0.00 0.02 3.71 1.89 5.90
182335 0.08 4.76 0.00 0.02 3.72 2.16 6.94
182230 0.06 4.39 0.00 0.02 2.93 2.75 8.84
182205 Bridge 0.02
182180 0.06 4.18 0.00 0.02 3.06 3.05 8.55
181950 0.08 5.19 0.00 0.02 3.44 1.99 7.09
180950 0.07 5.22 0.00 0.02 4.11 1.84 8.35
180320 0.12 4.57 0.00 0.02 2.04 1.58 4.54
179140 0.10 5.77 0.00 0.02 2.01 1.18 6.16
178800 0.10 5.77 0.00 0.02 2.14 1.21 6.35
178715 0.06 3.86 0.00 0.02 3.16 1.55 8.12
178700 Bridge 0.02
178685 0.06 3.29 0.01 0.02 4.31 4.44 7.42
219
178585 0.09 4.40 0.00 0.02 2.81 1.42 5.52
177845 0.08 3.27 0.00 0.02 2.57 1.46 5.40
176850 0.09 4.24 0.00 0.02 1.27 1.72 5.70
0.08 4.53 0.01 0.02 4.27 6.92 3.82 7.19
175515 0.08 4.93 0.00 0.01 1.51 2.33 3.99
175050 0.07 5.59 0.00 0.01 1.91 1.20 5.17
174740 0.05 6.31 0.00 0.01 3.56 1.69 7.31
174735 Bridge 0.01
174730 0.05 5.43 0.00 0.01 3.60 5.21 6.50
174640 0.06 5.14 0.00 0.01 2.59 4.27 5.83
173740 0.06 4.92 0.00 0.01 2.39 3.36 5.03
173620 0.06 4.93 0.00 0.01 2.34 3.48 5.22
173613 Bridge 0.01
173605 0.06 4.92 0.01 0.01 2.35 5.64 5.20
173500 0.08 4.55 0.02 0.01 1.88 6.17 3.77
173465 0.07 4.98 0.02 0.01 2.15 8.20 5.01
173458 Bridge 0.01
173450 0.07 4.97 0.00 0.01 2.16 3.34 4.99
173410 0.09 4.47 0.00 0.01 1.98 1.46 3.28
172200 0.08 5.39 0.00 0.01 1.67 1.99 4.29
171150 0.08 5.60 0.00 0.01 1.53 2.06 4.45
220
171050 0.05 5.30 0.00 0.01 2.70 2.91 6.28
171035 Bridge 0.01
171020 0.05 5.28 0.00 0.01 2.71 4.10 6.26
170940 0.08 6.01 0.00 0.01 1.22 1.99 4.49
169780 0.09 6.10 0.00 0.01 1.60 2.09 4.33
168560 0.09 5.83 0.00 0.01 1.87 1.73 4.11
168460 0.05 8.63 0.00 0.01 2.84 4.05 9.58
168410 Bridge 0.01
168360 0.05 8.62 0.01 0.01 2.84 9.39 9.56
168250 0.08 5.92 0.01 0.01 1.17 4.26 4.34
168200 0.14 5.80 0.01 0.01 2.09 3.12 2.50
168140 0.06 4.59 0.01 0.01 3.50 6.85 5.50
168115 Bridge 0.01
168090 0.05 2.88 0.01 0.01 5.41 5.50 4.42
168010 0.10 3.83 0.01 0.01 4.10 3.44 2.76
167840 0.13 4.58 0.00 0.01 3.59 1.23 2.46
167650 0.05 4.84 0.00 0.01 4.01 3.25 6.51
167575 Bridge 0.01
167500 0.05 4.84 0.00 0.01 4.01 3.25 6.51
0.07 5.35 0.00 0.01 3.97 4.73 3.71 5.16
167130 0.08 4.23 0.00 0.01 2.53 1.14 4.69
221
166770 0.15 4.11 0.00 0.01 3.60 0.93 2.28
166700 0.06 4.26 0.00 0.01 4.06 2.67 6.53
166675 Bridge 0.01
166650 0.06 4.11 0.01 0.01 4.33 6.49 6.38
166560 0.06 4.83 0.00 0.01 4.26 3.95 6.30
165760 0.06 4.86 0.00 0.01 4.31 3.49 6.53
164920 0.06 4.51 0.00 0.01 4.62 4.25 6.78
164890 0.06 4.32 0.00 0.01 4.45 4.05 6.46
164879 Bridge 0.01
164867 0.06 3.95 0.02 0.01 5.30 8.99 6.21
164800 0.05 4.80 0.00 0.01 5.54 2.88 7.32
163925 0.06 4.60 0.00 0.01 5.62 2.61 6.39
162800 0.05 5.65 0.00 0.01 6.07 2.72 8.32
162660 0.05 5.78 0.00 0.01 4.24 2.94 8.97
162615 Bridge 0.01
162570 0.05 5.71 0.01 0.01 4.26 9.35 8.89
162420 0.05 5.67 0.00 0.01 4.52 4.00 8.19
161970 0.05 5.35 0.00 0.01 5.51 3.78 7.74
161870 0.06 5.37 0.00 0.01 4.03 4.17 7.36
161750 0.06 5.34 0.00 0.01 4.01 1.59 7.31
0.06 4.86 0.00 0.01 4.08 6.34 3.89 6.81
222
161600 0.02 5.87 0.00 0.01 4.12 10.53 21.16
161400 0.04 4.36 0.00 0.01 3.98 4.34 9.52
161150 0.02 6.24 0.00 0.01 3.91 9.64 21.15
161141 0.02 6.24 0.00 0.01 3.91 9.64 21.15
161140 0.03 3.52 0.00 0.01 4.19 7.05 13.90
161091 0.03 3.52 0.00 0.01 4.20 7.02 13.84
161090 0.05 5.42 0.00 0.01 3.23 4.43 8.73
161055 0.05 5.36 0.00 0.01 3.27 4.39 8.65
160905 0.07 5.15 0.00 0.01 3.40 2.92 6.56
160405 0.08 5.11 0.00 0.01 3.45 2.64 5.93
159905 0.08 5.06 0.00 0.01 3.53 2.62 5.89
159405 0.08 5.30 0.00 0.01 3.38 2.63 5.91
159225 0.04 6.74 0.00 0.01 3.44 6.80 15.27
159217 0.04 6.75 0.00 0.01 3.44 7.75 15.27
159216 0.03 5.21 0.00 0.01 3.45 6.70 13.21
159166 0.03 5.20 0.00 0.01 3.45 6.70 13.21
159165 0.07 5.00 0.00 0.01 3.35 3.08 6.07
159140 0.07 5.01 0.00 0.01 3.34 2.27 6.09
158800 0.07 5.12 0.00 0.01 3.29 2.19 6.09
158500 0.07 5.21 0.01 0.01 3.24 4.58 6.09
158180 0.07 5.64 0.01 0.01 4.02 5.02 6.69
157080 0.10 6.12 0.01 0.01 3.81 3.78 4.95
223
156845 0.06 6.66 0.01 0.01 3.41 6.53 8.55
156795 0.05 5.77 0.01 0.01 2.65 7.68 10.05
156740 Bridge 0.01
156685 0.05 5.74 0.01 0.01 2.85 9.40 10.01
156635 0.05 5.76 0.01 0.01 3.52 10.03 10.68
156410 0.06 4.30 0.01 0.01 8.14 5.03 6.70
155990 0.04 6.38 0.04 0.01 5.57 23.27 11.98
155940 0.07 4.35 0.04 0.01 5.19 11.95 6.15
155923 Bridge 0.01
155905 0.06 3.49 0.04 0.01 5.36 10.97 5.65
155870 0.06 6.78 0.04 0.01 5.06 18.93 9.75
155835 0.03 6.49 0.04 0.01 3.65 34.90 17.97
155808 Bridge 0.01
155780 0.03 6.02 0.07 0.01 3.84 45.28 17.09
155730 0.06 4.25 0.07 0.01 8.23 17.04 6.43
154930 0.12 3.60 0.07 0.01 5.44 7.64 2.88
154880 0.08 3.85 0.07 0.01 2.26 12.35 4.66
0.05 5.29 0.02 0.01 10.35 8.28 9.38 10.11
154820 0.14 3.99 0.00 0.02 2.15 1.04 3.31
154380 0.08 3.82 0.00 0.02 2.35 1.57 5.60
154240 0.08 3.84 0.00 0.02 2.35 1.02 5.63
224
153990 0.08 3.83 0.00 0.02 2.35 2.19 5.63
153890 0.08 3.81 0.00 0.02 2.38 2.18 5.60
153825 0.05 4.70 0.00 0.02 2.39 4.03 9.74
153775 0.05 7.15 0.00 0.02 2.38 6.13 14.82
153738 Bridge 0.02
153700 0.05 7.00 0.00 0.02 2.38 5.69 14.62
153675 0.05 5.92 0.00 0.02 2.30 5.19 13.35
153635 0.04 3.31 0.00 0.02 5.24 5.09 10.46
152670 0.07 3.29 0.04 0.02 3.74 9.24 5.56
152620 0.04 7.11 0.04 0.02 2.68 28.25 16.99
152605 Bridge 0.02
152590 0.04 6.77 0.00 0.02 2.74 7.18 16.44
152540 0.07 2.54 0.00 0.02 4.10 2.26 5.18
151015 0.20 4.12 0.00 0.02 3.46 0.86 2.38
150525 0.13 3.49 0.00 0.02 3.07 0.96 3.15
150035 0.10 5.20 0.00 0.02 2.03 2.74 5.40
148580 0.10 5.57 0.00 0.02 3.22 2.95 5.83
148180 0.11 4.77 0.00 0.02 2.15 2.32 4.58
148130 0.08 4.77 0.00 0.02 1.71 3.26 6.44
148103 Bridge 0.02
148075 0.08 4.75 0.00 0.02 1.73 2.50 6.42
148025 0.14 4.35 0.00 0.02 3.24 1.36 3.49
225
146875 0.12 3.44 0.00 0.02 2.90 1.39 3.58
146825 0.09 2.79 0.00 0.02 2.42 1.63 4.18
146810 Bridge 0.02
146795 0.09 2.77 0.03 0.02 2.42 5.86 4.16
146745 0.11 2.96 0.03 0.02 2.84 4.85 3.44
145800 0.09 4.32 0.03 0.02 3.02 8.07 5.73
145750 0.08 2.58 0.03 0.02 2.84 5.87 4.16
145743 Bridge 0.02
145735 0.08 2.54 0.00 0.02 2.89 1.51 4.17
145685 0.10 1.86 0.00 0.02 3.95 1.01 2.77
144880 0.14 2.53 0.00 0.02 3.80 0.89 2.44
143470 0.15 2.78 0.01 0.02 5.32 1.39 2.39
142280 0.06 2.38 0.01 0.02 6.38 3.01 5.19
142230 0.04 4.12 0.01 0.02 6.52 6.36 10.98
142210 Bridge 0.02
142190 0.02 3.63 0.03 0.02 8.13 38.19 27.10
0.09 4.08 0.01 0.02 4.10 5.36 5.09 7.17
142140 0.02 3.38 0.00 0.01 5.64 4.11 15.36
141980 0.02 3.62 0.00 0.01 4.85 6.34 16.11
141680 0.03 3.92 0.00 0.01 4.68 4.13 10.92
141430 0.03 5.39 0.00 0.01 4.65 6.11 15.53
226
141210 0.03 5.11 0.00 0.01 4.72 6.56 15.02
141150 0.03 5.14 0.00 0.01 4.70 8.70 15.07
141115 0.03 1.62 0.00 0.01 4.86 4.03 6.98
141100 0.03 4.92 0.00 0.01 4.70 7.13 14.62
141050 0.03 1.56 0.00 0.01 4.96 3.31 6.78
141035 0.03 4.79 0.00 0.01 4.77 7.84 14.36
140995 0.03 1.53 0.00 0.01 4.98 3.67 6.73
140980 0.03 4.74 0.00 0.01 4.78 7.78 14.26
140940 0.03 1.43 0.00 0.01 4.91 3.50 6.42
140925 0.04 2.49 0.00 0.01 4.81 2.93 7.18
140830 0.03 4.82 0.00 0.01 4.77 5.67 14.41
140530 0.03 5.31 0.00 0.01 4.79 6.71 15.38
139234 0.03 6.55 0.00 0.01 4.66 7.73 17.70
139231 0.03 6.55 0.00 0.01 4.66 7.73 17.70
139230 0.03 4.85 0.00 0.01 4.65 6.53 14.52
139211 Bridge 0.01
139191 0.03 4.82 0.00 0.01 4.66 6.48 14.41
139190 0.04 2.84 0.00 0.01 4.61 3.32 7.38
139180 0.04 2.84 0.00 0.01 4.61 2.13 7.38
139030 0.03 2.86 0.00 0.01 4.64 3.94 8.07
138930 0.03 2.63 0.00 0.01 5.09 4.90 10.03
138780 0.02 2.35 0.00 0.01 7.11 4.93 12.09
227
138640 0.02 2.64 0.01 0.01 6.90 11.28 11.86
138630 0.02 2.20 0.01 0.01 6.96 11.55 12.15
138590 0.02 2.20 0.01 0.01 6.97 11.55 12.15
138580 0.02 2.13 0.00 0.01 7.13 5.04 11.93
138380 0.02 2.52 0.00 0.01 7.02 4.94 10.98
138265 0.02 2.80 0.00 0.01 6.93 7.19 15.99
138263 Bridge 0.01
138260 0.02 2.80 0.00 0.01 7.26 5.78 15.99
138060 0.01 5.80 0.00 0.01 7.27 11.40 31.51
138045 Bridge 0.01
138030 0.01 5.29 0.00 0.01 7.61 10.73 29.65
137970 0.01 4.23 0.00 0.01 7.85 13.94 25.56
137930 0.01 3.47 0.00 0.01 8.76 12.19 22.34
137928 Bridge 0.01
137925 0.01 4.19 0.00 0.01 8.26 12.98 25.36
137895 0.02 2.25 0.00 0.01 7.78 7.25 15.66
137860 0.02 2.02 0.00 0.01 7.90 6.32 13.66
137850 0.02 2.02 0.00 0.01 7.90 6.32 13.66
137845 0.02 2.01 0.00 0.01 7.94 7.57 14.48
137760 0.02 1.91 0.00 0.01 7.86 7.34 14.02
137750 0.02 2.04 0.00 0.01 7.81 7.50 13.74
137710 0.02 2.24 0.00 0.01 7.66 5.66 12.97
228
136810 0.02 2.09 0.01 0.01 7.05 12.29 13.09
136770 0.02 1.63 0.01 0.01 6.47 11.88 12.65
136740 Bridge 0.01
136710 0.02 1.63 0.00 0.01 6.84 5.31 12.56
136510 0.02 1.63 0.00 0.01 6.75 4.33 12.56
136410 0.02 1.70 0.00 0.01 6.76 3.96 9.70
135610 0.02 2.00 0.00 0.01 6.42 4.82 9.87
135410 0.03 2.43 0.00 0.01 5.51 4.64 9.51
135360 0.01 4.51 0.00 0.01 5.71 12.99 26.63
135310 0.01 4.51 0.00 0.01 5.72 14.82 26.63
135260 0.02 4.35 0.00 0.01 6.58 10.61 24.31
134710 0.02 4.49 0.00 0.01 6.18 10.81 24.76
134610 0.02 4.69 0.00 0.01 5.58 14.72 25.49
134360 0.02 4.95 0.00 0.01 5.22 15.24 26.40
134310 0.01 7.58 0.00 0.01 5.23 21.74 37.65
134300 Bridge 0.01
134290 0.02 4.83 0.00 0.01 5.38 15.03 26.04
134210 0.02 4.83 0.01 0.01 5.40 25.73 26.04
134110 0.01 4.66 0.00 0.01 6.11 9.39 27.21
133910 0.01 4.53 0.00 0.01 6.35 9.22 26.73
133710 0.02 4.57 0.00 0.01 6.22 8.64 25.04
133510 0.02 4.61 0.00 0.01 6.12 12.31 25.22
229
133310 0.02 4.60 0.00 0.01 6.18 6.15 25.22
133110 0.02 4.64 0.00 0.01 6.16 5.52 25.31
132885 0.02 4.32 0.00 0.01 6.08 5.26 24.13
132660 0.02 4.31 0.00 0.01 6.13 9.49 24.13
132435 0.02 4.44 0.00 0.01 6.02 5.36 24.58
132260 0.02 4.18 0.00 0.01 5.84 5.15 23.58
132010 0.02 6.06 0.00 0.01 5.75 12.77 30.23
131945 0.01 6.44 0.00 0.01 5.39 14.26 33.75
131935 Bridge 0.01
131925 0.01 6.14 0.04 0.01 5.48 70.59 32.68
131920 0.01 6.04 0.04 0.01 5.68 69.75 32.29
131915 0.01 6.04 0.04 0.01 5.68 69.75 32.29
131913 Bridge 0.01
131910 0.01 5.80 0.04 0.01 5.82 68.06 31.51
131890 0.01 5.87 0.04 0.01 5.73 68.69 31.80
131850 0.01 5.87 0.04 0.01 5.74 68.48 31.70
131835 Bridge 0.01
131820 0.01 5.50 0.01 0.01 5.89 30.79 30.43
131760 0.02 4.11 0.01 0.01 5.45 22.19 21.94
131560 0.02 4.21 0.01 0.01 4.78 24.04 23.76
131385 0.02 3.87 0.00 0.01 5.34 10.97 22.49
131185 0.02 3.86 0.00 0.01 5.22 10.93 22.40
230
130985 0.02 4.00 0.00 0.01 5.38 15.57 21.51
130785 0.02 3.68 0.00 0.01 5.14 13.84 19.12
130585 0.02 4.07 0.00 0.01 5.17 11.63 21.76
130410 0.02 3.81 0.00 0.01 5.19 4.85 22.21
129960 0.01 3.21 0.00 0.01 5.14 15.39 21.26
129885 0.01 6.10 0.00 0.01 4.99 23.58 32.58
129860 Bridge 0.01
129835 0.01 5.73 0.00 0.01 5.06 22.07 31.21
129785 0.02 1.64 0.00 0.01 4.98 8.95 12.65
129635 0.02 2.30 0.00 0.01 4.80 9.33 13.20
129485 0.02 3.62 0.01 0.01 4.27 24.47 21.49
129395 0.01 5.83 0.01 0.01 4.75 36.00 31.60
129365 Bridge 0.01
129335 0.01 5.52 0.00 0.01 4.95 16.93 30.43
129285 0.02 1.74 0.00 0.01 5.00 7.34 13.20
129015 0.02 2.15 0.00 0.01 4.00 6.18 12.67
0.02 3.88 0.00 0.01 13.60 17.63 13.67 19.44
128915 0.02 2.43 0.00 0.02 3.22 3.55 20.44
128715 0.04 2.89 0.00 0.02 3.04 5.26 11.13
128415 0.04 2.95 0.00 0.02 2.94 2.02 9.84
128015 0.04 2.85 0.00 0.02 2.80 1.50 9.65
231
127185 0.04 2.77 0.00 0.02 2.86 2.13 9.70
126565 0.03 2.63 0.00 0.02 2.85 2.75 11.83
126460 0.03 2.60 0.00 0.02 2.86 2.73 11.70
126450 0.04 2.52 0.00 0.02 2.86 1.88 8.07
126425 0.04 2.49 0.00 0.02 2.98 1.65 8.03
126375 0.04 2.45 0.00 0.02 3.05 3.10 9.98
126355 0.03 2.42 0.00 0.02 3.10 5.31 11.92
126335 0.03 2.06 0.00 0.02 3.97 1.61 11.96
126225 0.03 2.07 0.00 0.02 3.96 2.67 10.37
126075 0.03 2.05 0.00 0.02 3.99 2.53 10.30
125975 0.03 2.05 0.00 0.02 4.00 4.59 10.30
125875 0.03 4.02 0.00 0.02 4.17 5.00 19.43
124450 0.03 4.02 0.00 0.02 3.61 6.66 15.67
123450 0.04 4.21 0.00 0.02 2.66 5.92 13.92
123310 0.04 4.69 0.00 0.02 2.67 6.53 15.36
123260 0.03 4.69 0.00 0.02 2.68 7.62 17.92
123255 Bridge 0.02
123250 0.03 4.63 0.00 0.02 2.68 5.69 17.79
123200 0.03 4.63 0.00 0.02 2.68 5.51 17.22
122940 0.03 3.58 0.00 0.02 4.10 4.36 13.61
122770 0.03 5.77 0.00 0.02 3.81 6.92 24.73
122720 0.03 7.12 0.00 0.02 3.81 7.64 26.31
232
122685 Bridge 0.02
122650 0.03 6.37 0.00 0.02 3.82 9.30 24.46
122620 0.03 3.32 0.00 0.02 4.20 5.79 15.22
122370 0.04 4.16 0.00 0.02 3.41 2.55 12.43
121720 0.04 4.60 0.00 0.02 3.09 4.50 12.37
121220 0.04 7.07 0.01 0.02 2.73 12.53 20.18
121170 0.04 6.87 0.01 0.02 3.30 12.29 19.80
121150 Bridge 0.02
121130 0.04 6.76 0.01 0.02 3.18 17.11 19.64
0.03 3.87 0.00 0.02 5.30 14.20 5.29 14.73
121030 0.04 3.42 0.00 0.01 2.95 1.76 7.50
119800 0.04 4.94 0.00 0.01 2.32 2.16 10.30
119320 0.04 7.06 0.00 0.01 2.18 3.13 14.94
119250 0.04 7.18 0.00 0.01 2.08 3.17 15.11
119235 Bridge 0.01
119220 0.04 7.08 0.04 0.01 2.09 31.92 14.99
119160 0.04 4.62 0.00 0.01 2.31 1.58 10.64
116720 0.04 6.06 0.00 0.01 2.23 1.41 13.48
115420 0.04 6.51 0.00 0.01 2.30 8.40 14.17
115070 0.04 6.52 0.00 0.01 2.41 8.40 14.17
115000 0.04 6.96 0.00 0.01 2.41 8.77 14.78
233
114975 Bridge 0.01
114950 0.04 6.95 0.00 0.01 2.42 5.14 14.78
114775 0.03 7.38 0.00 0.01 2.18 6.94 19.95
114600 0.02 7.23 0.00 0.01 2.35 8.39 25.31
114500 0.01 7.25 0.00 0.01 2.34 10.56 38.07
114410 0.01 7.31 0.00 0.01 2.58 10.62 38.28
114360 0.01 7.32 0.00 0.01 2.58 10.62 38.28
114310 0.01 6.09 0.00 0.01 3.58 12.78 33.81
114260 0.01 6.16 0.00 0.01 3.57 8.00 34.11
113985 0.01 6.32 0.00 0.01 3.56 10.30 34.72
113860 0.01 6.35 0.00 0.01 3.55 10.33 34.82
113760 0.01 5.94 0.00 0.01 3.89 9.87 33.30
113485 0.01 5.98 0.00 0.01 3.85 10.50 33.40
113410 0.01 6.02 0.00 0.01 4.30 10.57 33.61
113310 0.01 6.21 0.00 0.01 3.66 3.60 34.32
113010 0.01 6.31 0.00 0.01 3.57 3.63 34.62
112430 0.01 6.03 0.00 0.01 3.63 3.52 33.61
112230 0.01 5.59 0.00 0.01 3.81 3.35 31.98
111510 0.01 5.45 0.00 0.01 3.78 3.30 31.47
111410 0.01 5.18 0.00 0.01 3.88 3.18 30.36
111310 0.01 5.85 0.00 0.01 3.69 5.99 33.00
111210 0.01 6.04 0.00 0.01 3.44 3.53 33.71
234
110760 0.01 6.04 0.00 0.01 3.44 3.53 33.71
110600 0.01 6.19 0.00 0.01 3.40 3.59 34.21
110595 Bridge 0.01
110590 0.01 6.10 0.00 0.01 3.40 3.55 33.91
110510 0.01 6.12 0.00 0.01 3.40 3.57 34.01
110060 0.01 5.85 0.00 0.01 3.36 3.46 33.00
110020 0.01 6.04 0.00 0.01 3.36 3.53 33.71
109981 0.01 5.82 0.00 0.01 3.36 3.45 32.89
109980 0.01 4.93 0.00 0.01 3.83 3.09 29.44
109951 Bridge 0.01
109921 0.01 4.93 0.01 0.01 3.83 37.04 29.44
109920 0.02 6.51 0.01 0.01 3.34 41.60 33.07
109880 0.02 6.51 0.01 0.01 3.34 41.60 33.07
109780 0.02 6.32 0.00 0.01 4.56 10.59 27.01
108850 0.05 6.17 0.01 0.01 4.54 10.58 10.19
108740 0.05 6.48 0.01 0.01 4.87 10.06 9.70
108395 0.05 6.42 0.01 0.01 4.96 10.01 9.64
106440 0.05 6.48 0.00 0.01 2.97 4.39 9.13
106210 0.07 5.97 0.00 0.01 2.88 3.30 6.88
106010 0.06 5.36 0.00 0.01 4.25 3.67 7.63
105960 0.06 5.36 0.00 0.01 4.27 3.73 7.77
105600 0.06 6.29 0.00 0.01 3.36 3.76 7.82
235
105200 0.06 6.23 0.00 0.01 3.46 3.72 7.75
104874 0.05 6.56 0.00 0.01 3.62 4.51 9.39
104740 0.06 6.81 0.01 0.01 3.63 6.26 8.37
103850 0.05 5.88 0.00 0.01 4.82 3.43 8.74
103780 0.05 4.43 0.00 0.01 4.71 3.01 7.68
103680 0.04 4.55 0.00 0.01 4.76 4.38 11.17
103630 0.04 6.10 0.00 0.01 4.78 5.32 13.56
103608 Bridge 0.01
103585 0.04 5.75 0.01 0.01 4.79 10.13 13.04
103525 0.04 5.04 0.01 0.01 5.24 8.33 10.71
102845 0.04 5.86 0.00 0.01 4.31 4.84 11.55
102705 0.04 6.19 0.00 0.01 4.08 5.29 12.61
102655 0.04 9.29 0.00 0.01 4.20 6.59 15.71
102618 Bridge 0.01
102580 0.04 8.90 0.03 0.01 4.37 28.29 15.28
102540 0.04 5.55 0.03 0.01 4.38 19.16 10.35
102480 0.04 5.54 0.03 0.01 4.39 19.16 10.35
102400 0.04 6.19 0.03 0.01 4.19 24.64 13.31
0.03 6.15 0.00 0.01 11.17 15.77 8.81 21.51
236
Appendix F. Mill Creek Wastewater Treatment Plant Flow Data, April 15
th
and 16
th
1998.
Date Discharge (MGD)
15-Apr-98 124.2
15-Apr-98 123.5
15-Apr-98 120.9
15-Apr-98 118.0
15-Apr-98 113.6
15-Apr-98 108.3
15-Apr-98 94.0
15-Apr-98 94.9
15-Apr-98 97.7
15-Apr-98 100.5
15-Apr-98 118.0
15-Apr-98 119.3
15-Apr-98 136.6
15-Apr-98 134.9
15-Apr-98 138.6
15-Apr-98 205.6
237
15-Apr-98 181.6
15-Apr-98 180.3
15-Apr-98 180.6
15-Apr-98 184.7
15-Apr-98 178.0
15-Apr-98 175.2
15-Apr-98 155.0
15-Apr-98 157.4
15-Apr-98 169.8
16-Apr-98 195.2
16-Apr-98 398.7
16-Apr-98 372.4
16-Apr-98 372.1
16-Apr-98 387.9
16-Apr-98 401.0
16-Apr-98 393.6
16-Apr-98 381.5
16-Apr-98 385.1
16-Apr-98 376.4
238
16-Apr-98 214.7
16-Apr-98 368.9
16-Apr-98 374.6
16-Apr-98 328.8
16-Apr-98 313.5
16-Apr-98 305.6
16-Apr-98 290.9
16-Apr-98 296.9
16-Apr-98 289.9
16-Apr-98 293.4
16-Apr-98 295.2
16-Apr-98 292.3
16-Apr-98 273.4
16-Apr-98 271.5
16-Apr-98 266.2
16-Apr-98 274.8
239
Mill Creek WWTP Flow 15 & 16 April 1998
04/16/1998 1:03
04/16/1998 11:01
0. 0
50. 0
100.0
150.0
200. 0
250. 0
300. 0
350. 0
400. 0
450. 0
Time (24-hour)
Fl
ow
(M
G
D
)
240
Appendix G: Data Dictionary
Data
Description Class
Attribute Units
05080002_rf3 River Reach File for
HUC 05080002
Polyline
05090202_rf3 River Reach File for
HUC 05090202
Polyline
05090203_dem DEM For HUC
05090203 from
Basins 2
Grid Value Feet
05090203_rf3 River Reach File for
HUC 05090203
Polyline
10.precip HEC-HMS
precipitation file for
a 10-year design
storm
Text file
3dxsects Cross section line
theme
Polyline
addAsOutlets Shapefile with the
outlets/junctions
manually added for
the analysis of Mill
Creek
Point Id
241
Data
Description Class
Attribute Units
Boundary Shapefile with the
bounding polygons
generated for the
floodplain analysis
Polygon Profile_id
bounds Stream definition
point theme of
cross section
locations
Point
Build Shapefile of Mill
Creek buildings
Polygon Elevation Feet
Burned_dem DEM raised 1000m
except in streams
Grid Value Meters
Calibration#.run HEC-HMS files with
the Simulate/Run
configurations
Text file
Calibration.contr
ol
HMS file with the
control
specifications used
for the analysis of
parameters
Centerline Shapefile of the
stream centerlines
used
PolyLine Is_outlet
Length
Reach_id
242
Data
Description Class
Attribute Units
used Stream_id
Cleanrf River Reach file
edited to exclude
lakes or banks
Polyline
Comp.dbf DBase attribute
table of Statsgo
DBF file
Curvenumber Curve Number Grid
of Mill Creek
Grid Value Curvenu
mber
Demgrid 1 degree by 1
degree seamless
DEM provided by
Louisville Corps of
Engineer District
Grid Value meters
Demgridp 1 degree by 1
degree seamless
DEM provided by
Louisville Corps of
Engineer District
Clipped to HUC
05090203 projected
into Ohio State
Plan
Grid Value meters
Fdr.avl Theme color
243
Data
Description Class
Attribute Units
scheme
Flood Shapefile
representing the
flooded areas
corrected from the
fa?? files
Polygon
Floodmap.apr ArcView project for
the Mill Creek
containing scripts
and menus needed
for floodplain
mapping
Text file
gagespro Shapefile of the Mill
Creek gages
defined in CRWR-
PrePro projected in
Ohio State Plane
Point Feet
Gridpt Shape file of DEM Point Elevation Meters
hecdiv.dbf Table for attribute
transfer from
ArcView shape
files to HMS basin
files
DBF file
244
Data
Description Class
Attribute Units
hecjunct.dbf Table for attribute
transfer from
ArcView shape
files to HMS basin
files
DBF file
hecreach.dbf Table for attribute
transfer from
ArcView shape
files to HMS basin
files
DBF file
hecres.dbf Table for attribute
transfer from
ArcView shape
files to HMS basin
files
DBF file
hecsink.dbf Table for attribute
transfer from
ArcView shape
files to HMS basin
files
DBF file
hecsourc.dbf Table for attribute
transfer from
ArcView shape
files to HMS basin
DBF file
245
Data
Description Class
Attribute Units
files
hecsub.dbf Table for attribute
transfer from
ArcView shape
files to HMS basin
files
DBF file
Huc Shapefile of HUC
05090203
Polygon Feet
Hydrol# Shape files
generated by HEC-
PrePro with
hydrologic
information
necessary for HMS
Polyline
Hydrop# Shape files
generated by HEC-
PrePro with
hydrologic
information
necessary for HMS
Point
land.avl Theme color
scheme
Levee Shapefile of Mill Polygon Feet
246
Data
Description Class
Attribute Units
Creek levees
lfp Longest flow path
calculated for each
sub-basin
Grid Value
lulc Shapefile of the Mill
Creek area land
useaccordingto
the USGS
Polygon Lucode Anderso
n?s land
use
code
MCbasinSCSv1 Basin file generated
by CRWR-PrePro
for the analysis of
Mill Creek
Text file
MCfag Flow accumulation Grid Value Drainag
earea
measure
dincells
Mcgridp DEM clipped for the
Mill Creek area
projected in Ohio
State Plane,
Grid Value Feet
MClnk Stream network
links of the Mill
Creek watershed
Grid Value
247
Data
Description Class
Attribute Units
MCmodout Outlets manually
added to create
watersheds as
described by the
Louisville District
Grid Value
MCmodstr Modified Stream
network for Mill
Creek based on a
1000-cell threshold
Grid Value
Mcout Outlets calculated
for the Mill Creek
basin considering
the junction added
manually
Grid Value
MCrvr Shapefile with the
river network
determined from
centerl_m
PolyLine Length
WshCode
StreamVel
MuskX
Route
MuskK
LagTime
TimeStep
MCstr Stream network for
Mill Creek based on
Grid Value
248
Data
Description Class
Attribute Units
a 1000-cell
threshold
MCwshd Subwatersheds
delineated for each
outlet in MCmodout
Grid Value
MCwshdply Shapefile with the
subbasins
determined from
MCwshd
Ploygon Area,
Baseflow,
Transform,
Lossrate,
CurveNum,
LagTime,
LagMethod
Merge5 Merged RF3 files
for HUCs
05090203,
05090202, and
05080002
Polyline
Mill Creek
Basin.hms
HEC-HMS project
file for Mill Creek
Text file
Mill.prj HEC-RAS project
file for Mill Creek
Text file
MCBasinSCSv1.
map
HEC-HMS map file
for the Mill Creek
Text file
249
Data
Description Class
Attribute Units
watershed
MillCreek.f01 HEC-RAS flow
profiles for the
different junctions
at different times for
the 10-year event
Text file Cubic
feet per
second
Millcrk2.g01 HEC-RAS
geometry import file
Text file Feet
Millfdr Flow direction Grid Value Arc/Info
flow
direction
code
Millfill Filled DEM based
on burned_m
Grid Value Meters
Milltin TIN terrain
representation for
the Mill Creek area
TIN Elevation Feet
prepro04.apr ArcView project for
the Mill Creek
PrePro analysis
Text file
Railroad Shapefile of Mill
Creek rail network
Polygon Feet
250
Data
Description Class
Attribute Units
Rcn.txt Lookup Table for
Curvenumber
Text file
Roads Shapefile of Mill
Creek road network
Polygon Feet
Soils Shapefile of the Mill
Creek area soils
accordingtothe
USGS
Polygon
Soilstorage Soil Storage Grid of
Mill Creek
Grid Value Inches
Stream3d 3D line shapefile of
stream centerline
and banklines
PolylineZ
streamp.txt Table with the
stream parameters
Text file Muskingu
mX
Stream
veloc.
m/s
Syml# Shape files
generated by HEC-
PrePro with
hydrologic
information
251
Data
Description Class
Attribute Units
necessary for HMS
Symp# Shape files
generated by HEC-
PrePro with
hydrologic
information
necessary for HMS
Thiessen8 Shape file
generated using
Thiessen Polygons,
with the
precipitation are
corresponding to
each of the 8 gages
in the basin
Polygon Area
Water_m Subwatersheds
delineated for each
outlet in moutlet_m
Grid Value
water1.avl Theme color
scheme
Water2.avl Theme color
scheme
watertin* TIN representing TIN
252
Data
Description Class
Attribute Units
the water surface
watpol_m Shapefile with the
subbasins
determined from
water_m
Polygon Area,
Baseflow,
Transform,
LossRate,
CuerveNu
m,
LagTime,
LagMethod
WshPar.txt Table of watershed
hydrologic
parameters
Text File
.
253
References
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Report. Center for Research in Water Resources, Austin, Texas, 1999.
(4) Azagra, Esteban. Rainfall Runoff in the Guadalupe River Basin.
Center for Research in Water Resources, Austin, Texas, 1998.
(5) Azagra, Esteban. Regional Hydraulic Model for the City of Austin.
Center for Research in Water Resources, Austin, Texas, 1999.
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Information Systems. Masters Thesis, Department of Civil Engineering,
University of Texas at Austin, Austin, TX. 1994.
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Environmental Protection Agencies BASINS Webiste.
http://www.epa.gov/OST/BASINS/
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Information Systems.2
nd
ed. Oxford University Press, Oxford, UK.
1998.
(9) Chow, V.T., Maidment, David R. and Mays, L.W. Applied Hydrology.
New York, 1998.
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Modeling. Hydrologic Processes, 5, 115-124. 1991.
254
(11) Egenhofer, M.J. and Golledge A.G. Spatial and Temporal Reasoning in
Geographic Information Systems. Oxford University Press, Oxford, UK.
1998.
(12) Federal Emergency Management Agency Website.
http://www.fema.gov
(13) Cincinatti Metropolitan Sewer District Website. http://www.msdgc.org/
(14) Hellweger, F. and Maidment, D.R. HEC-PREPRO: A GIS Preprocessor
for Lumped Parameter Hydrologic Modeling Programs, CRWR Online
Report 97-8. Center for Research in Water Resources. University of
Texas at Austin. 1997.
(15) Jenson, S.K. and Dominique, J.O. Extracting Topographic Structure
from Digital Elevation Data for Geographic Information Systems
Analysis. Photogrammetric Engineering and Remote Sensing, 54(11),
1593-1600. 1988.
(16) Maidment, D.R., Olivera, F. and Reed, S. HEC-PrePro: An ArcView
Pre-Processor for HEC's Hydrologic Modeling System. Center for
Research in Water Resources. University of Texas at Austin. 1998.
(17) Maidment, David R. Handbook of Hydrology. New York, 1993.
(18) Olivera, F. CRWR-PrePro. Center for Research in Water Resources.
Austin, TX. http://www.ce.utexas.edu/prof/olivera/prepro/prepro.htm.
1999.
(19) Quasim, Syed, R. Wastewater Treatment Plants: Planning, Design,
and Operation. Technomic Publishing Company, Inc. Lancaster, PA,
1999..
255
(20) Tate, E.C. Mapping Using HEC-RAS and ArcView GIS.Masters
Thesis, Department of Civil Engineering, University of Texas at Austin.
1998.
(21) U.S. Army Corps of Engineers, Hydrologic Engineering Center.HEC-
HMS Hydrologic Modeling System: User?s Manual. Version 1.0.
Hydrologic Engineering Center, Davis, CA, 1998.
(22) U.S. Army Corps of Engineers, Hydrologic Engineering Center.HEC-
RAS River Analysis System: User?s Manual. Hydrologic Engineering
Center, Davis, CA, 1998.