Research On Urban Waterlogging Based On PRS And SWMM Model

With the rapid development of global warming and urbanization,the ecological environment has been seriously damaged,which has led to a series of natural disasters.Among them,the most frequent and most serious urban waterlogging problem has seriously affected the economic development of most cities in China.Compared with other major coastal cities,the problem of waterlogging in Nanchang has not been paid enough attention.In addition,there is a wide and close relationship between disasters,and there are mutual influences and promotions.How to analyze the problem of waterlogging in Nanchang and find out its main inducing factors needs to be studied.In this chapter,we select the phase 2 images of Nanchang from Landsat 8 in2013 and 2017,extract the surface cover information by supervised classification,The surface temperature of Nanchang city is inversed by a single-window algorithm.The results of statistics and experiments show that in recent years,the precipitation in Nanchang is fluctuating and increasing,the number of rainstorms is increasing,the surface temperature is rising,the NDVI and MNDWI are decreasing,and the NDBI is rising,which increases the risk of urban waterlogging disaster.Through the Pressure State Response(PSR)model.From the statistical yearbook data of Nanchang from 2008 to 2017,the vulnerability index data of urban waterlogging in Nanchang was extracted.The Analytic Hierarchy Process(AHP)is introduced to calculate its corresponding weight,and the index of vulnerability to waterlogging in Nanchang is given,to analyze the problem of waterlogging in Nanchang.The results show that the density of drainage pipeline,green coverage,per capita road area and annual average temperature are the main factors that affect the vulnerability of the waterlogging in Nanchang,and their weight is more than 10%.Secondly,GDP per capita,construction land area,rainstorm times and annual precipitation will also have a certain impact on the problem of waterlogging in Nanchang,with a weight of 5%-10%.The influence of population,domestic sewage discharge and its treatment rate on the problem of waterlogging in Nanchang is less than 5%.Based on the field survey,existing pipe network distribution map,arcgis3 d analysis and urban rainstorm runoff model(SWMM)simulation,the direction of campus rainwater runoff are analyzed,and the rainstorm drainage with a return period of 3 years is simulated.The simulation results show that under the condition of 3-year rainfall,the branch roads of the campus department can not meet the requirements of the rainstorm drainage with a return period of 3 years,and the problem of water accumulation in the canteen area of the north area is the most serious heavy waterlogging.On this basis,according to the main indicators of waterlogging disaster vulnerability obtained in the previous chapter,two low impact development strategies(LID)are proposed for rainwater garden and sunken green space.The experimental results show that the strategy can effectively alleviate the waterlogging disaster in the campus.