Water Environment Comprehensive Evaluation Of Wuyi River Valley

Wuyi river, the largest tributary of Jinhua river, flows through Yongkang and Wuyi. With rapid socio-economic development in the basin, water pollution is getting serious. And It has greatly impacted not only Wuyi river water environmental and ecological security, but also Qiantang River water environmental.Based on the water quality monitoring and background analysis on the Wuyi river, this research has analyzed the spatial-temporal changes of water quality, synthetically evaluated the water quality of Wuyi river, then identified the main causes of water pollution. On this basis, thoughts and plans about water pollution control have been raised, which have important theoretical and practical significance to improve the quality of Wuyi river Basin's water environment, use water resource rationally, optimize the industrial layout, promote the socio-economic sustainable development and achieve sustainable development of water resource.(1) The research show that the water quality of different period of time changes greatly. The changes between dry season and wet period and between business downtime and operating period, has impacted water quality of the study area seriously. In general, the Pollution index values in February are at a low level. From beginning of March, the main pollution index values increase gradually, and reach their peaks in April or May.(2) The distribution of leading industries on Wuyi river valley has a great impact on the water quality of different river sections. The water quality of Shiya, Tongqin and Huchu sections in which phosphatizing enterprises are concentrated is poor. The major industrial pollution indexes, such as TP and F~- have reached their peaks at Shiya, and Tongqin sections. The water quality indexes have a different degree of improvement in the scope of Wuyi. And every water quality index has reached the normal range at Jiaoyan section.(3) With the general analysis of pollution source on different regions, different times, as well as the weights of the participating indexes, the research shows that the main cause of water pollution in Wuyi river is industrial pollution, and the major pollutant is phosphorus. This is just accord the situation of the industrial development of the study area whose major industry is phosphatizing industries.(4) Wuyi river has poor water quality in general, there are four levels in the monitoring section, including level one, two, three and five. The water quality emerges gradually good posture after bad variation from upstream to downstream: Guangyao section, as a background section, has the first-level water quality; Mingzhaoqiao section located in a tributary named Shu river of the Wuyi river has better water quality belongs to level one, before entering Wuyi; Shiya, Xijinqiao and Huchu sections have gathered plenty of phosphating enterprises, so the water quality belongs to level five; After entering Wuyi, because of phosphatization-related enterprises reducing and part of phosphorus pollution precipitating and falling down into the bottom sediments, the water quality gets better gradually, reaching level three and two. All is directly link with the main source of phosphorus pollution, its transfer formation and distribution of enterprise in the Wuyi river vally.(5) Chla is closely related to TP. Excessive TP has caused eutrophication of Wuyi river, which is also the key factor of water deterioration.(6) Aim at the characteristics of industrial phosphorus pollution, the paper has pointed that industrial pollution prevention; especially the phosphorus pollution prevention should be targeted to the first place in the research on water environment remediation such as water pollution control and management. And also attentions should be paid to the remediation of non-point source pollution and system construction in the pollution prevention and control.