Simulation Study On Control Of Runoff Pollution (SS) In Urban Stormwater System By LID Measures

With the continuous development of urbanization level,the proportion of hardened area on the ground is getting higher and higher,and the pollution of rainwater runoff formed by rainfall is becoming more and more serious.In order to protect the ecological environment and achieve sustainable development of urbanization,China is now promoting the use of low impact development(LID)to control storm runoff pollution.LID is an international advanced scheme for rainwater control and utilization.By means of various source control and management measures such as infiltration,filtration and detention,rainwater runoff pollution control is achieved.However,the research on LID in China started relatively late,resulting in the lack of theoretical basis and technical support for the popularization of this technology.In this paper,a certain area in Kunming is selected as the research area.SS(suspended particulate matter)is chosen as the research object of pollutants,and the SWMM software is used to model the research area.Water quality is simulated by adding different LID scheme in the study area after the analysis of control effect of these programs on surface runoff of SS,features and performance advantages to explore different LID schemes,designed to provide basis and reference for city rainwater runoff pollution control.The simulation results show that:(1)with reference to the SWMM user manual and the related literature,the parameters of SWMM are s·et,and the results of the model are quite different from the actual conditions.Before using SWMM for simulation,the sensitivity parameters of the model should be determined to ensure the accuracy of the SWMM simulation results.(2)the current situation of rainwater system in the study area can control the SS in stormwater runoff better in the case of p=0.5a,while the control effect of rainwater system on SS is worse when p=1a,2a and 5A are present,and SS will pollute the environment greatly.(3)single LID measures,on runoff SS control effect was as follows: rain garden,narrow sunken green space,permeable pavement;but LID measures not in the shortage of land under the effective control of rainwater runoff pollution,non-point source pollution in Kunming City reached(SS)reduction rate the requirements of48%.(4)LID measures,on runoff SS control effect was as follows: Rain Garden-permeable pavement combination rain garden-> special downgoinggrassland >combination of permeable pavement narrow sunken green space combination,and the rain garden-permeable pavement combination can reach Kunming city of non-point source pollution(SS 48%)reduction rate requirements.(5)considering the rationality of LID scheme,the LID scheme of SS pollution and the improvement of the effect,the total load reduction effect,the concentration peak reduction effect,determine the rain garden-permeable pavement combination for rainwater runoff pollution control plan for the best SS.