Research On Water Pollution Control In Erhai Basin Based On Grey Theory

Water is not only the indispensable substance for both human beings and creatures to live by, but the unsubstitutable natural resources for industrial and agricultural production, economic development, and environmental improvement. However, in the past two decades, with rapid economic development and population growth, natural resources in Lake Erhai basin were over exploited, leading to sharp ecological deterioration. Water pollution in Lake Erhai Watershed has become increasingly problematic, which restricts severely the local socio-economic sustainable development. Establishing an effective water pollution control policy is becoming the focus of socio-economic sustainable development in the watershed area. In this dissertation, based on investigation and diagnostic analysis of the water pollution status, we built a prediction model of GM (1,1) and analyzed the predicted results, providing a scientific support for the comprehensive treatment of water pollution in Lake Erhai Watershed. The scopes of this study involve the following considerations:1. Analysis on water pollution status in Lake Erhai basin.The major water pollution indexes in the watershed include concentrations of nitrogen and phosphor, and chemical oxygen demand. Water quality monitoring data indicated that water quality deteriorated day by day and was gradually changing fromâ…¡toâ…¢between 1993 and 2009. The following factors, as the unreasonable industry structure, the increased pollutants inflow and production, the undeveloped clean water recycle mechanism, the damaged water body ecology, and insufficient manpower devoted to the environmental management, were found to be attributable to the serious water pollution problem.2. Forecast and analysis on water pollution in Lake Erhai basinWater pollution in Lake Erhai Watershed directly restricted the socio-economic sustainable development. It is necessary to build the prediction model of GM (1,1) as guidance for water pollution control. Depending on the monitoring data of the three water quality indexes referred above, the modeling and analysis were carried out. Compared with the true value, the modeling precision exceeds 95%, which demonstrats that GM (1,1) model is feasible for the prediction of the Lake Erhai water pollution. The predicted results show that the trend of water pollution in the watershed is not optimistic, and the water pollution control is of great urgency. 3. Water pollution control in Lake Erhai basin.According to the analysis on water quality status and secular trend, water pollution control was put on the agenda. The water pollution control and treatment mechanism has been proposed as follows:source control in structure, pollution treatment engineering, ecological rehabilitation.