Non-point Source Of Rainfall And Runoff Around Fu River In Baoding City Pollution Characteristics Research

With the continuous optimization of pollution control measures in Baoding City,when the point source pollution control has achieved good results,the problem of non-point source pollution from rainfall runoff has gradually become prominent.The pollutants formed by rainfall and runoff wash away the pollutants on the surface into the receiving water bodies such as Fuhe River and make the water bodies The water quality deteriorated further,destroying the ecological balance of water bodies.The gradual improvement of people’s living standards has imposed stricter requirements on the quality of water environment.Therefore,research on non-point source pollution of rainfall runoff in Baoding City has played a certain role in promoting water environment improvement.Three monitoring sections are set up in the upper,middle and lower reaches of the selected sections of the Fuhe River.Three different underlying surfaces of roofs and green spaces,as well as different functional zones,set up monitoring points to conduct continuous sampling to study the characteristics of rainfall runoff pollutant concentrations of different underlying surfaces over time.Through the analysis of natural rainwater samples,it is found that the pollution of natural rainwater in Baoding City is relatively serious,and the temporal and spatial distribution of pollutants are quite different.Through the analysis of water quality samples of different sections of the Fuhe River,it is found that the spatial and temporal distribution characteristics of pollutant concentrations in different sections are different,and the input of nutrient pollutants in the Fuhe River water body has relatively small spatial differences.Through the comparative study of the pollutant content in different periods of Fuhe River,it is found that the content of CODcr and TP are affected by both point source and non-point source pollution,and the content of NH4+-N is largely derived from point source pollution.Through sampling and analysis of runoff from roads,roofs and green spaces,it is found that the surface runoff water is seriously polluted,and the pollution degree of the underlying surface is ranked as follows:road surface>roof surface>green space.In different functional zones,road runoff attenuation in traffic areas is not obvious,and road runoff concentration in commercial and residential areas decreases significantly.Through the analysis of the correlation of pollutants in the runoff of different underlying surfaces,it is concluded that the TSS in the runoff has a good correlation with the concentration of TP,CODcr and NH4+-N pollutants.Most of the pollutants in the runoff have an initial scour effect,and the overall performance of the initial scour is that 40%of the runoff can carry 50-60%of the pollution load.The initial erosion of road surface runoff in traffic areas in different functional areas is lower than runoff from commercial areas and residential areas.The greater the rainfall intensity,the more obvious the initial erosion effect.Using the rainfall runoff pollution load estimation model,the annual load of various runoff pollution indicators in Baoding can be estimated.The calculation results show that the annual load of road runoff pollution is higher than that of green land and roof runoff.The traffic area has the largest annual load,the commercial area is in the middle,and the residential area has the smallest annual load.