Simulation Evaluation Of Low Impact Development(LID)Design Of Shenyang Agricultural University Based On Swmm

At present,the traditional city parks or residential area planning and design,are to pay attention to the form,a large number of gray pavement,high price allows natural ecology into artificial ecology,such function degradation,ignoring the inherent power of ecological regulation and storage of rainwater can.This paper first introduces the concept of the development of low impact,and then summarizes the current low impact development technology.Relying on Shenyang Agricultural University,according to the basic information of the research area,the landscape of the LID transformation layout program.The SWMM model established in the study area based on the principle of operation and briefly introduce the SWMM software model,based on regional division in the catchment area,on the basis of the literature,combined with the corresponding campus situation,determine the hydrological parameters required for calculus.Based on the Shenyang rainstorm intensity formula,the rainfall process of the 2h in 2,5,and three years of rainfall was simulated to simulate the rainfall correlation in the study area.The results showed that:in the 2,5,and 20 years of reproduction period,the reduction rate of LID measures on runoff was 88.31%,79.02%,and 66.81%,respectively.Thus,the use of LID measures to reduce the amount of runoff,with the increase of the recurrence period,runoff reduction rate gradually reduced.The flood peak reduction rate is 76.41%,70.46%,and 58.50%,respectively.It can be seen that the LID measure has a great effect on the reduction of the peak period of rainfall,with the gradual increase of the return period,the ability of LID to reduce the peak value gradually decreases.Changes of water quality in the discharge system are as follows:in 2,5,20 year return period,LID measures the total load of COD reduction efficiency were 80.32%,73.33%,62.84%;the total load on the TSS reduction efficiency were 80.32%,73.31%,62.81%;the total load on the TP reduction efficiency were 80.23%,73.19%,62.50%.The total load reduction rate of TN was 80.31%,73.31%and 62.79%,respectively.The total load reduction rate of ammonia nitrogen was about 80.31%,73.33%,and 62.81%,respectively.To conclude,LID measures for total suspended particles(TSS),chemical oxygen demand(COD),total nitrogen(TN),total phosphorus(TP)and ammonia nitrogen removal effect is very good,their removal effect is not the same,The removal of LID was increased with the removal rate of five kinds of pollutants.The design can reduce the runoff reduction rate to 88.4%in the recurrence period of the study area,reduce the peak flow by 76.41%,and purify the water by more than 62%.The rational use of LID measures can effectively improve the ability of regional drainage system to cope with heavy rainfall,so as to control and reduce rainwater storage from the source.At the same time,it also has a certain demonstration significance to other campus rainwater management planning and design projects.Especially for China,a country with extreme shortage of water resources,it has more important significance.