Research On The Water Function Zoning Of Taihu Lake

In the 1980s, with the fast development of economy and urbanization process, water pollution has aggravated heavily, and the water pollution event has happened frequently. In 2005, there was nearly 40 percent water quality of Yellow river branch was worse then V type, and lost drinkable function basically; the Huai River which had 78.7 percent reach didn't accord for drinking water standard in the 2000 km accessed reach; the HongZe Lake local water pollution was out of standard worsely, and the eutrophication trend was obviously, and lead to the water quality fell down yearly; the outbreak of blue-green algae in MeiLiang Bay resulted in WuXi drinking water crisis in May 2007.The water pollution event reflects the ponderance of the water pollution of drinking water source and lake of water source eutrophication, and establishing the water function zoning reasonable and scientificly is the foundation work of the water resources development of using and protecting , which is the basis for the management of water resources.The paper chose Taihu Lake as the study area, on the basis of Taihu Lake environmental quality data and two-dimensional flow-pollutants model, and in combination with GIS method to research on the pollution diffuse rule of Taihu Lake inflow river, analyzed the water quality as CODMn,TP,TN,BOD₅ for water quality index from 2000 to 2006, and got the water function zoning of Taihu Lake for each year and average year ,which may contribute to the environmental regulations and general management of Taihu Lake.The main conclutions of this paper are as follows:(1) According to Environmental quality standard for surface wate, analyzing the water quality based on the water quality model and GIS method, and according to the principle of water function zoning, got the water function zoning and the compositive water function zoning for Taihu Lake from 2000 to 2006 , contrasted to present water function area in 2006, compared the water function zoning graph between years, analyzed the compositive water function zoning graph from water quality and water function area range .(2) Based on the water function area, the flux of pollutants through main inflow fiver channels of the Taihu Lake was calculated. It was get the results for reaching the water quality aim of the water function area.