Source Identification Of Water Pollution Combined With Hydrochemistry And Socioeconomic Parameters In River Basins

Accurate identification of potential contamination sources of river water is a basis for effective pollution control and sustainable water management.Aiming at the problems of subjectivity,one sidedness and low accuracy in the identification results caused by the traditional multivariate statistical analysis technology only using hydrochemical indicators or simply combining socioeconomic parameters,this study explores the method of combining socioeconomic parameters and hydrochemical indicators to achieve a comprehensive assessment on pollution sources with accurate estimates of source identification and apportionment.Considering the availability and representativeness of the dataset,the middle section of Meishan in Min River Basin was selected as the research area of this study,and the research methods such as cluster analysis（CA）,principal component analysis（PCA）and APCS-MLR receptor model were used to comprehensively analyze the data of 11 monitoring sites,14 water quality indicators and 12 socioeconomic parameters in the study area from 2015to 2017,revealing the temporal and spatial pollution characteristics and potential pollution sources of water quality in the study area..The specific results are as follows:（1）The spatial-temporal pollution heterogeneity of water quality in the study area is obvious.The results of cluster analysis showed that the 12 months were clustered into three categories:normal water period,wet period and dry period;in space,11 monitoring points were grouped into two categories:low pollution area and high pollution area.Spatio-temporal clustering results show that the pollution difference of each water quality indicator is more significant in space,so the follow-up research is based on the spatial classification results.The correlation results showed that the organic matter indicators COD_Cr,COD_Mnand BOD₅ in the two regions showed significant positive correlation with NH₄⁺-N,TN,TP and Chl-a.DO and E.coil showed significant differences in the two areas.DO was significantly negatively correlated with most water quality indicators in the high-pollution area,while E.coil was positively correlated,indicating that the pollution in the high-pollution area was more serious.（2）The influence degree of socioeconomic parameters on water quality indicators shows that:in the low pollution area,NH₄⁺-N,TN and COD_Cr in water body were closely related to livestock and poultry breeding wastewater and domestic sewage,and TP had the highest correlation with agricultural planting pollution;in the high pollution area,NH₄⁺-N,TN and COD_Cr in water body were highly correlated with industrial wastewater,livestock and poultry breeding wastewater and domestic sewage,while TP was weakly correlated with these pollution sources.The results of the correlation degree between various socioeconomic parameters show that:the correlation between various socioeconomic parameters in the high-pollution area and the low-pollution area is roughly the same,but the difference is that the area of construction land in high-pollution areas also shows a significant positive correlation with the number of enterprises,GDP and the added value of township industries,which indicates that industrial enterprises in high-pollution areas are widely distributed and economic development is closely related to the development of construction land.（3）The results of pollution source analysis of hydrochemical indicators and socioeconomic parameters show that:in low-pollution areas,four potential pollution factors were extracted from water quality indicators,and three potential pollution factors were extracted from socioeconomic parameters,respectively.The comprehensive analysis results showed that the main pollution sources were domestic sewage,livestock wastewater,agricultural planting and phytoplankton growth,industrial wastewater,and the corresponding contribution rates were 35.48%,30.73%,17.60%and 10.88%.Four potential pollution sources were extracted from the water quality indicators and socioeconomic parameters in the highly polluted areas.Comprehensive analysis showed that the potential pollution sources were industrial wastewater,livestock wastewater,domestic sewage and phytoplankton growth,natural factors and agricultural planting,with corresponding contribution rates of 33.83%,28.57%,18.30%and 14.76%.The results show that the analysis of water pollution sources in river basins by combining hydrochemistry with socioeconomic parameters can improve the accuracy of pollution source identification results,reduce subjectivity and one-sidedness,and provide more reliable theoretical basis and guidance for water pollution control.