Browsing by Subject "Hydrologic models"

Now showing 1 - 7 of 7

Arc Hydro data model for Ethiopian watersheds
(2005-12-24) Asamenaw, Seyoum Ayele; McKinney, Daene C.
Ethiopia is endowed with a substantial amount of water resources. The country’s renewable surface and ground water amounts 123 and 2.6 billion cubic meters per annum, respectively, but its distribution shows high temporal and spatial variation. The Ministry of Water Resources of Ethiopia (MoWR) planned to develop a digital hydrologic data model that supports management of the country’s water resources. The purpose of this project is to use the Arc Hydro data model organize and manage water resource data in Ethiopia. To accomplish this, raw Shuttle Radar Topographic Mission (SRTM) data was processed and a 90m*90m Digital Elevation Model (DEM) was created. Second, drainage lines and watersheds were created using the Arc Hydro tools. Third, six hydro administrative regions were identified based on the flow direction of the streams. This project has shown that Arc Hydro is an effective tool for storing and analyzing hydrologic information for very large areas
Evaluating enhanced hydrological representations in Noah LSM over transition zones : an ensemble-based approach to model diagnostics
(2009-12) Rosero Ramirez, Enrique Xavier; Yang, Zong-liang
This work introduces diagnostic methods for land surface model (LSM) evaluation that enable developers to identify structural shortcomings in model parameterizations by evaluating model 'signatures' (characteristic temporal and spatial patterns of behavior) in feature, cost-function, and parameter spaces. The ensemble-based methods allow researchers to draw conclusions about hypotheses and model realism that are independent of parameter choice. I compare the performance and physical realism of three versions of Noah LSM (a benchmark standard version [STD], a dynamic-vegetation enhanced version [DV], and a groundwater-enabled one [GW]) in simulating high-frequency near-surface states and land-to-atmosphere fluxes in-situ and over a catchment at high-resolution in the U.S. Southern Great Plains, a transition zone between humid and arid climates. Only at more humid sites do the more conceptually realistic, hydrologically enhanced LSMs (DV and GW) ameliorate biases in the estimation of root-zone moisture change and evaporative fraction. Although the improved simulations support the hypothesis that groundwater and vegetation processes shape fluxes in transition zones, further assessment of the timing and partitioning of the energy and water cycles indicates improvements to the movement of water within the soil column are needed. Distributed STD and GW underestimate the contribution of baseflow and simulate too-flashy streamflow. This work challenges common practices and assumptions in LSM development and offers researchers more stringent model evaluation methods. I show that, because of equifinality, ad-hoc evaluation using single parameter sets provides insufficient information for choosing among competing parameterizations, for addressing hypotheses under uncertainty, or for guiding model development. Posterior distributions of physically meaningful parameters differ between models and sites, and relationships between parameters themselves change. 'Plug and play' of modules and partial calibration likely introduce error and should be re-examined. Even though LSMs are 'physically based,' model parameters are effective and scale-, site- and model-dependent. Parameters are not functions of soil or vegetation type alone: they likely depend in part on climate and cannot be assumed to be transferable between sites with similar physical characteristics. By helping bridge the gap between the model identification and model development, this research contributes to the continued improvement of our understanding and modeling of environmental processes.
Geographically integrated hydrologic modeling systems
(Center for Research in Water Resources, University of Texas at Austin, 2004-05) Whiteaker, Timothy Lee
GIS-based hydrologic and hydraulic modeling for floodplain delineation at highway river crossings
(Center for Research in Water Resources, University of Texas at Austin, 2000-12) Anderson, David James; Maidment, David R.
Hydrologic model for the Rio Conchos basin: calibration and validation
(Center for Research in Water Resources, University of Texas at Austin, 2009-05) Ingol-Blanco, Eusebio; McKinney, Daene C.
Hydrologic modeling of the Pecos River basin below Red Bluff Reservoir
(2011-05) Yalcinkaya, Sedat; McKinney, Daene C.; Maidment, David R.
The segment of the Pecos River that extends from Red Bluff Reservoir until it discharges to the Rio Grande/Bravo near Langtry was studied in this project. Hydrologic behavior of the basin was analyzed between 1981 and 2000, the first ten year period for calibration and the second ten year period for validation by using Water Evaluation and Planning Software (WEAP, SEI, 2006). Simulated streamflows were compared with naturalized streamflows (RJBCO, 2003) at two control points, one in the middle of the basin near Girvin and the other one is at the end of the basin near Langtry. The purpose of the project is to create a valid model for water availability simulations in the Pecos River Basin to be used for future water availability simulations considering climate change effects. The basin was divided into two parts in order to evaluate the results, the upper basin and the entire basin (below Red Bluff reservoir) according to the location of control gages. Simulated streamflows closely match the naturalized flows at the Girvin station in the upper basin. Although the results at the Langtry station for the entire basin are not as good as Girvin, the model still reproduces streamflows well enough to represent the hydrologic behavior of the basin, especially for the base flow. Considering the complex geological structure of the Pecos River Basin below Red Bluff Reservoir, the results can be considered satisfactory. The model can be used for future water availability predictions in the basin considering climate change effects.
WEAP hydrology model applied: the Rio Conchos Basin
(Center for Research in Water Resources, University of Texas at Austin, 2006-12) Amato, Charlotte C.; McKinney, Daene C.; Ingol-Blanco, Eusebio; Teasley, Rebecca Lynn