Modeling Surface Soil Erosion and Sediment Transport Processes in the Upper North Bosque River Watershed, Texas

A sediment transport module added to the Hydrologic Engineering Center's Hydrologic Modeling System (HEC-HMS) Version 4.0 computes surface erosion, reach routing, and reservoir trap efficiency. The HEC-HMS sediment transport module was applied to the Upper North Bosque River Watershed (UNBRW) in central Texas, a well-instrumented watershed with good parameterization and calibration data, to test model robustness. The UNBRW is 98% rural including rangeland, forage, and dairy waste application fields. Simulation results were compared to observed average daily total suspended solid (TSS) data at five gauge locations. The HEC-HMS results matched observed TSS across the UNBRW (<1% error at all gauges) during model calibration and maintained modest residuals (-31 to 12% error) during the validation period. The HEC-HMS also performed well compared to published results through two other commonly used models. (C) 2015 American Society of Civil Engineers.