Brass Model: Practical Aspects

Abstract

The BRASS (Basin Runoff and Streamflow Simulation) model was developed to provide flood management decision support for operation of Savannah River system projects. BRASS is an interactive hydrologic/hydraulic model which can perform rainfall‐runoff simulation for subareas, using the Soil Conservation Service curve number infiltration procedure, continuously simulate variation in curve number and baseflow for subareas using rainfall and evaporation data, perform unit hydrograph and controlled storage routing of subarea runoff, and perform dynamic streamflow routing for combining subarea outflows and determining stage, discharge, and velocity histories at points throughout a dendritic river system. The model incorporates and enhances two previously developed hydrologic models and the National Weather Service river forecast model, DWOPER, linked by a command program using “problem‐oriented language” (POL) input. Because BRASS effectively merges hydrologic and hydraulic models for watershed analysis, it has numerous applications in project operations, flood forecasting (including tidally influenced areas), and design of flood or water control structures.