Stormwater Management Model(SWMM):Principles,Parameters and Applications

Stormwater management model(SWMM) is a model most suitable for estimating surface runoff and its pollution load among the widely used models.SWMM has been successfully used in estimating and predicting surface runoff processes,surface runoff and pollution load during storm floods in urban areas,and planning,analyzing and designing combined and separate sewers,sewage pipes and other drainage systems.The main principles of modules of SWMM and their estimations were analyzed,and the calibration methods for main parameters and their sensitivities were summarized.It was found that the sensitive parameters in SWMM included percent of impervious area,surface infiltration capacity,width of overland flow path,depth of depression storage of impervious surface,length and internal diameter of conduit.Several existing problems in SWMM and corresponding suggestions for the future improvements were proposed.