| Water resources are one of the important resources for the survival and development of human society.With the rapid development of urban modernization and industrialization,water pollution has become an important issue in protecting environmental quality.Taking Liaocheng as the research area,this paper analyzes the overall temporal and spatial variation of water quality with the help of the multivariate statistics-based water quality analysis method,and analyzes it from another perspective by combining the methods of land use transfer matrix,non-point source pollution estimation,and equal standard pollution load.The main pollutants and pollution sources that cause water pollution are given in turn,and scientific water pollution prevention measures and suggestions are given.The following main conclusions are drawn:（1）Among the four major rivers in Liaocheng City,Wei Canal has the best overall water quality and stable water quality;the water quality along the upstream and downstream of the Majia River and the Jindi River varies greatly,and the water quality is relatively unstable;the water quality along the Tuhai River is relatively stable.The results of spatial cluster analysis show that the water quality of the four monitoring sections of Zhongzimiao,Rentangqiao,Lifengtao and Wangdikou are relatively poor,which is mainly concentrated in the southwest of Liaocheng City,showing a certain spatial aggregation.The main pollutants in the monitoring section of the Majia River’Rentangqiao are nutrients such as N and P,agricultural activities and livestock and poultry breeding have a greater impact on the water quality;the main pollutants in the monitoring section of the Jindi River’s Zhongzimiao is organic,and the water quality is affected by the point source discharge of municipal sewage;the monitoring sections of Lifengtao and Wangdikou of Tuhai River are close to each other,mainly due to organic pollution,which comes from the discharge of domestic sewage and industrial wastewater.（2）The results of the land use matrix in Liaocheng City show that the main land types are cultivated land,urban villages,industrial and mining land,and water areas.From 2000 to 2010,the areas of urban villages,industrial and mining land,grasslands,woodlands,water areas and unused land increased,the increased urban villages and industrial and mining land mainly came from cultivated land.The area of cultivated land decreased,mainly transferred to urban villages and industrial and mining land,and a small part was transferred to waters.From 2010 to 2018,the area of urban villages,industrial and mining land,forest land,and water areas increased,and the increased urban villages,industrial and mining land mainly came from cultivated land.The area of arable land,grassland and unused land decreased,among which the area of arable land decreased and was mainly transferred to urban villages,industrial and mining land and water area.In general,from 2000 to 2018,the area of grassland and cultivated land decreased,and the area of cultivated land decreased the most,mainly transferred to urban villages,industrial mining land and some water areas.（3）Among the non-point source pollution in Liaocheng City,the main wate r pollutant emissions of rural domestic sewage are as follows:COD>TN>NH3-N>TP;the main water pollutant emissions of planting industry are as follows:TN>TP>NH3-N;the main water pollutant emissions of aquaculture industry are as f ollows:COD>TN>NH3-N>TP.Among the point source pollution in Liaocheng City,the main water pollutant emissions of industrial wastewater are as follow s:COD>TN>NH3-N>TP;the main water pollutant emissions of urban domestic sewage are as follows:COD>TN>NH3-H>TP.（4）Among the pollution sources in Liaocheng,urban domestic sewage,livestock and poultry breeding industry,and rural domestic sewage have a greater impact on the water environment;among different water pollutants,TN has a greater impact on the water environment.Among the counties（urban areas）in Liaocheng,Dongchangfu District and Chiping District mainly put forward pollution prevention and control measures for urban domestic sewage and rural domestic sewage.Poultry farming and planting are the main sources of measures and suggestions;Guan County and Dong’e County are the main sources of water pollution are planting and livestock and poultry farming;Linqing City and Gaotang County focus on the management of industrial wastewater countermeasures and suggestions. |
