A GIS-based Subcatchments Division Approach for SWMM

Abstract

Storm Water Management Model (SWMM) is a digital hydrological model which is widely used for the simulation of rainfall-runoff processes in urban catchment. SWMM is a distributed model, which means a study urban catchment needs to be divided into several irregular subcatchments first before simulation. However, most of the existing subcatchments division approaches for the SWMM are not able to capture the characteristics of the spatial variability in topography and hydro information of urban catchment. In this paper, a new subcatchment-division approach for SWMM is proposed. Two existing division method are combined together in this approach by using Geographic Information System (GIS), which can make the subcatchments fully reflect the hydrological features of the urban catchment, thus further improve the simulation results of SWMM. The actual application results show that the SWMM using the subcatchment dividing by the approach in this paper is more reliable than other existing SWMM in urban region.