Assistant Professor University of Texas at Arlington
The use of widely available coupling frameworks that integrate hydrodynamic and hydrologic models is one approach to generate flood inundation maps; however, most of them have significant computing complexity and costs. Recent advances in hydrogeomorphic, topography-based inundation mapping approaches can offer cost-efficient solutions to these computational constraints, making them ideal for scenarios demanding quick decision making and situational evaluation. Research into integrating these topography-based techniques with a hydrologic model to simulate streamflow and flood inundation extents over large river networks is still in its early stages. We aimed to bridge this gap in this study by integrating a topography-based approach Height Above the Nearest Drainage (HAND) with a globally used hydrologic model Soil and Water Assessment Tool (SWAT). This integration was facilitated via a semi-automatic workflow with potential for immediate operationalization. We evaluated our models over the Texas Gulf region of the United States involving 15,000 distinct stream segments and a total drainage area of roughly 415,000 km2. Since SWAT is among the few globally applicable models capable of simulating hydrological and ecological processes, our efforts to integrate SWAT with a flood mapping tool will assist studies beyond traditional flood management and risk mapping by increasing the efficiency of floodplain ecology, water quality, and habitat research over large river network scales.
