Research On Urban Waterlogging Prevention Technology Based On Storm Water Management Model

In recent years,the national economy has been developing rapidly.To meet the needs of urbanization,it has caused a certain degree of damage to the original natural underlying surface.With the extreme weather occurred frequently,the risk of urban waterlogging disasters continues to increase.This study is based on the SWMM model(Storm Water Management Model),Simulate the waterlogging changes before and after LID(Low Impact Development)measures in the study area under rainfall in different recurrence periods.The paper mainly analyzes the effect of runoff control and the overload situation of node and pipe network.In terms of simulation construction:combining the basic data of the area to divide the sub-catchment area and generalize the rainwater pipe network;design five different rainfall scenarios with different recurrence periods according to the basic rainfall data of Beijing;design six LIDs according to the characteristics of each LID measure layout scenarios,the layout area of each scenario is 21565m~2.The simulation results show that:after six types of LID measures are arranged in the study area,they all have obvious effects on waterlogging prevention and control.In terms of peak reduction and emission reduction,scenario 1(arrangement of permeable pavement)has the best effect,and the runoff reduction ratio is 11.36%-28.57%,but scenario 4(arrangement of permeable pavement and concave green land)is not much different from it;In terms of flood peak reduction,combined LID measures are better than single LID measures during the low recurrence period,and scenario one and scenario four are slightly better than other scenario arrangements during the high recurrence period;in terms of the delay effect of runoff flood peaks,Scenario 2(with concave green land)has the best effect,and the delay time is 1-9min;each LID scenario has a certain control effect on the overload situation of nodes and pipeline networks.There hasn't node or pipe network overload occurs when P=2a,P=5a.Combined with the analysis of hydrological effect,waterlogging prevention effect and economy of each LID scenario layout,it is determined that permeated pavement-concave green land is the best waterlogging prevention measure.