Eutrophication Evaluation and Nutrients Changes Trend Forecast of Wanfu Lake in Anhui Province

Utilizing the monitoring data of Wanfu Lake from 2001 to 2007 in Anhui Province,adopting synthetic evaluation(TLI) method to evaluate eutrophication and based on the grey system theory of constructing three gray dynamic model groups composed of GM(1,1) to forecast the nutrient salt changing tendency of Wanfu Lake,the results indicate that the comprehensive nutrition condition indexes of Wanfu Lake in 2007 is 33.537,which lies in the nutritional level,the eutrophication degree is influenced by water period slightly,and shows that by the means of the grey system theory the density of TN increases dramatically while the density of TP decreases remarkably.The gray dynamic model group method,which uses statistical average of model groups as the final prediction and avoids the instability of only one gray model method,can make full use of recent water quality data to forecast the changing trend.And prediction result is greatly meaningful for protecting the local drinking water and sustainable developing fresh water resource.