Anal Ysis Of Characteristics Of Rainfalland Surface Runoff Pollution In Industrial Parks Of Coastal Cities And Research On Regulation Of Low-impact Development Measures

With the rapid development of urban economy and the continuous improvement of infrastructure,the characteristics of poor water permeability and wide sources of pollutants in industrial parks have made the problem of rainfall and surface runoff pollution increasingly serious.Solving the problem of rainfall and surface runoff pollution in industrial parks can not only protect the surrounding water,but also maintain sustainable economic development.This paper takes the industrial parks of coastal cities as the research object,selects three typical rainfalls in the industrial parks for sampling and detection,and uses SWMM to establish a generalized model of the rainwater pipe network of the industrial parks,compares the change trends of the instantaneous concentration of pollutants in different rainfall runoffs,and calculates the Event Mean Concentration(EMC)of runoff pollutants,carry out erosion analysis and correlation analysis of runoff pollutants,compare the simulation results and actual measurement results of some runoff pollutants,and analyze the effects of low-impact development measures on regional rainfall surface runoff and runoff pollution Regulation effect.The specific research content is as follows:Taking conventional pollutants SS,COD,TN,TP and heavy metal pollutants Cu,Zn,Pb as the detection indicators,the detection data shows that the instantaneous concentration of surface runoff pollutants reaches the maximum at the beginning of rainfall,and the instantaneous concentration of runoff pollutants from three rainfall events The trend of change is from high to low,and then gradually gradual;the calculation results of the Event Mean Concentration(EMC)of runoff pollutants show that the water quality of rainfall and surface runoff in the industrial park is poor;the cumulative erosion curve and erosion intensity curve of pollutants are drawn,and the results show: Both conventional pollutants and heavy metal pollutants have obvious initial erosion phenomena.The erosion intensity of runoff pollutants in the early stage of the industrial park is higher than that in the middle and late stages;correlation analysis shows that the runoff pollutants COD,TN,TP,Cu,Zn,Pb and suspended matter SS has a certain correlation;the simulation results of runoff pollutants SS,COD,TP,and TN have relatively small deviations from the measured results.The control effects of low-impact development measures were analyzed under the conditions of 1,2,3,5,and 10 years of return period.The results showed that the interception,retention,and infiltration of low-impact development measures themselves can reduce the regional runoff coefficient and reduce the total regional runoff.Flood peak flow,discharge outlet inflow,discharge outlet pollutant load,delay the peak time,alleviate the load phenomenon such as node water accumulation and full flow of pipes and channels,and help the stable operation of the regional drainage system;with the continuous increase of the return period,The saturation characteristics of low-impact development measures gradually weaken the regulation effect of the entire area,and the reduction rate of the load reduction of various runoff pollutants shows a downward trend.