Performance of a Conceptual and a Physically-Based, Distributed Model in Simulating Extreme Events over a Semi-Urbanized Watershed in San Antonio, Texas
Abstract
The need for accurate hydrologic analysis and rainfall-runoff modeling tools has been rapidly increasing due to the growing complexity of operational hydrologic and hydraulic problems associated with population growth, rapid urbanization, and expansion of agricultural activities. Given the recent advances in remote sensing of physiographic features and the availability of near real-time precipitation products, rainfall-runoff models are expected to predict runoff more accurately. In this study, we compare the performance and implementation requirements of two rainfall-runoff models for a semi-urbanized watershed. One is a semi-distributed conceptual model, the Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS). The other is a physically-based, distributed-parameter hydrologic model, the Gridded Surface Subsurface Hydrologic Analysis (GSSHA). Two flood events that took place on the Culebra Creek watershed, a sub-watershed of the San Antonio River basin in Texas, were used in this study. The two models were driven by the Multi-sensor Precipitation Estimator radar products. A recent event (in 2015) was used for model validation. Simulation results generated by GSSHA on a 75-meter square grid and driven by multi-sensor rainfall estimates compared well to the observed flow over the 82 mi2 sparsely urbanized watershed. The results demonstrate the advantage of using quality controlled radar products in distributed hydrologic modeling. These products typically characterize the spatial and temporal distribution of rainfall better than do rain gauges, although the resolution of the MPE product used here is much coarser than the native resolution of the weather radar. Results of the comparison provide further evidence of using more appropriate models in representing the rainfall variability for flood generating storms.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H13J1830S
- Keywords:
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- 1821 Floods;
- HYDROLOGY;
- 1834 Human impacts;
- HYDROLOGY;
- 1847 Modeling;
- HYDROLOGY;
- 1932 High-performance computing;
- INFORMATICS