Analysis and governance countermeasures study of water environment problems in typical cities around Dongting Lake in the Yangtze River Basin

Six cities were taken as the research object to analyze the water environment pollution problems of Dongting Lake and the Yangtze River Basin caused by cities in Dongting Lake region, and put forward the corresponding countermeasures. The water quality variation of the state-controlled sections, characteristics of water resources and heavy metal pollution of the six cities in the region were summarized, and the pollution load of industrial sources, urban domestic sources, and urban non-point sources were calculated. The results showed that the loading of COD, ammonia nitrogen, TN and TP discharged by the 6 cities in this region were 140 700, 12 100, 24 500 and 1 400 t/a, respectively. The main pollution sources were urban domestic sources, followed by industrial sources and urban non-point sources. The main factors affecting urban water quality in this region were ammonia nitrogen and total phosphorus. Through analyzing the urban water environment problems in this region, it was found that the imperfect construction of the pipe network was one of the important reasons for the deterioration of urban water quality, and the expansion of industrial scale and the problems left over from industrial history led to the discharge of industrial wastewater and heavy metal pollution. Based on the above analysis, the corresponding governance suggestions for urban water environment problems were put forward.