Based On SWMM Sponge Urban Flood Control And Drainage Effect Evaluation

With the advancement of our country urbanization, the urban impervious percentage increased dramatically, green area reducing, at the bottom of the urban river hardening. Hot climate warming, the city to the effect caused by the frequent extreme weather and sudden heavy rain. Rain, short confluence time, larger, peak time of the peak flow in advance. And most of the urban drainage pipe network in our country old, hard to meet the requirements of urban development. On the other hand most of the city there is a shortage of water resources, long-term groundwater, resulting in a decline in groundwater level. In addressing the urban rainwater management, therefore, an urgent need to an advanced management concept rain. Sponge city management idea, as a kind of advanced rainwater resources is not only beneficial to solve the urban waterlogging disasters, storm runoff pollution, and can collect rainwater use and recharge of groundwater, etc. Is of great significance for China’s ecological civilization construction of city.This article first study compared the sponge city construction in China and the developed countries of rainwater resource management concept. Collect related information, from the existing drainage, drainage partition, rainstorm characteristics, historical analysis of the current situation of dandong city flood control and drainage waterlogging and Angle. On the basis of dandong city station drainage partition is chosen as the study area. Made a study of regional urban transformation, sponge target, planning period, sponge urban renovation technology route. According to the research area of the underlying surface analysis, from the permeability function is given priority to, stored, combination way has three different kinds of sponge the urban reform scheme. Collection point in front of the drainage pipe network, DEM figure of water area, the land use data, and through the spatial analysis functions such as ArcGIS, completed the drainage pipe network generalization, the catchment area, average slope analysis, etc. Extract the relevant data, completed the station drainage partition of SWMM model.Synthetic runoff coefficient and the history of waterlogging check proof, the parameters of model calibration and verification. The present status of application of station drainage of SWMM model partition drainage pipe network capacity is analyzed. Set up three different rainfall scenarios, once every two years, once every five years, and in 2013 the typical heavy rains. Comparison of the three different retrofit scheme under the same rainfall scenarios of the differences between flood control and drainage effect. And different rainfall scenario, the same kind of sponge retrofit scheme of different city. Each kind of sponge city reconstruction scheme, in the case of a return period of small, can have very good effect on flood control and drainage. Return period, give priority to with infiltration of plan a and to store the three, to reduce the peak flow and delayed effect on flood peak moment, there is no obvious difference. But the combined function of three, flood control and drainage effect is obvious. Three kinds of scheme can effectively improve the drainage ability of drainage pipe network. Return period when the effect is more obvious, the increase of return period, because of the low impact development measures related saturated, on the improvement of the drainage pipe network co., LTD.