Sediment Transport Modeling in HEC RAS

Abstract

Sediment transport capabilities have been added to the Hydrologic Engineering Center's River Analysis System program (HEC-RAS). HEC RAS can perform mobile bed sediment routing computations with quasi steady (histogram) flow series data. For each flow in the time series a water surface profile is calculated. Hydraulic parameters required for sediment processes are also calculated. The model calculates sediment transport capacity by a number of available methodologies. The sediment continuity equation is then solved in conjunction with sorting and armoring algorithms to solve for the actual volume of deposition or erosion. Additionally, temporal entrainment and deposition functions similar to those employed in HEC-6 have been adapted. This paper discusses the equations and methodologies that have been added to HEC-RAS for the inclusion of sediment transport modeling. Additionally, the graphical user interface, which is used to enter sediment data and visualize results, will be shown.