Investigation And Analysis Of River Water Environment And Non-Point Source Pollution In Baimatang-Wuzhen River,the Main River Of Wuzhen Town

Wuzhen is a famous 5A tourism attraction in China,where there are many water networks and local water environment quality directly affects the development of tourism and the life of Wuzhen residents.In this study,Baimatang-Wuzhen river,the main river in Wuzhen,was selected as the research object.By means of data collection and analysis,in-situ survey,personnel interview and sampling analysis,a systematic investigation and analysis were carried out in terms of river morphology,function orientation,water system hydrology,water environment quality,main pollution sources and pollution load of main river.In accordance with the monitoring data of water quality in the past two years,the main causes of water pollution in Wuzhen are screened out in attempt to provide with the proposals for improving water quality later on.The main findings are as follows:1.Based on the limits of Class ? Water Quality Indexes under the National Environmental Quality standard of surface water,it can be seen from the analysis of the inter-annual change of pollution factors in Wuzhen River watershed:In 2017,the water quality compliance rate was 100%at each monitoring section in Wuzhen River Watershed.In 2018,the compliance rates of NH3-N and CODMn were 100%,however,that of TP was 37.5%only.2.An obvious spatial and temporal variation of concentration of NH3-N was noted following winter>spring>summer>autumn.The average concentration of each point reached the class ? water standard.The TP pollution degree of Baimatang is the highest,and the average concentration of each point in the four seasons exceeds the class ? water standard in summer and autumn.The qualified rate of CODMn concentration in four seasons was 100%.3.From the results of water quality evaluation,the overall qualified rate of single factor evaluation of three sections of Baimatang is 43%,that of Jinniutang is 72%,and that of Wuzhen river is 58%.The pass rate of the comprehensive quality assessment of the three sections of Baimatang was 57%,the pass rate of the comprehensive quality evaluation of the three sections of Jinniutang was 79%,and the pass of the comprehensive quality evaluation of the two sections of Wuzhen river was 60%.4.Although the annual average values of NH3-N,TP,and CODMn of the section of Beizha Bridge from 2017 to 2018 have reached the Class ? water standard,the single-factor analysis water quality within 5 months of 2017 is Class IV,and the single-factor analysis water quality within 7 months of 2018 is Class ?.5.Through investigation,analysis and estimation of river water quality and water environment carrying capacity of Wuzhen City,urban living pollution,rural living pollution,tourism pollution,non-point source pollution from planting and pollution from aquaculture,the main reasons for poor water quality in Wuzhen City were obtained First,the objective limitation of the carrying capacity of the river water environment in Wuzhen City,and the second is that the aquaculture industry and rural domestic sewage are the main sources of urban river pollution.