Dynamic Analysis of Water Quality in Changsha Part of Xiang River form 2000 to 2005

Objective To understand the water quality in Changsha part of Xiang River,and to provide scientific basis for controlling pollution,and constructing and developing the city.Methods Water samples were collected at three sections of clean,pollution and self-purification in wet and dry seasons to detect and evaluate water quality based on the environmental quality standards and testing requirements for surface water.Results Water quality of three sections in Changsha part of Xiang River was seriously polluted.The main pollutants were coliform,mercury,volatile phenol,cadmium,and ammonia nitrogen,etc.The pollution of ammonia nitrogen,volatile phenol,cadmium,and coliform in dry season was significantly higher than that of the wet period(P0.01～P0.05).Mercury pollution was serious in the two seasons,but the pollution in wet season was more serious than in dry season(P0.01).The exceed standard indexes of upstream monitoring points in 2000 and 2005 were higher than those of the middle and lower reaches,which suggested that pollution in the upstream cities was more serious.Conclusions Pollution of the water in Changsha part of Xiang River is serious,and a number of indicators exceed the standards of three types of surface water quality.The government and the relevant departments should pay more attention on the water quality.