Effects Of Ecological Restoration On Phosphorus Concentration And Studies On Phosphorus Prediction Model Of Huizhou West Lake

In this paper,based on the monitoring before and after ecological restoration of aquatic ecosystem in Nannanhu lake,part of Huizhou West lake,has analysised the effects of ecological restoration on the water phosphorus concentration.It also biult the Phosphorus model and forecast the change of water quality before and after the ecological restoration.Fish removal experiments in Huizhou West Lake show that the concentration of total phosphorus increased significantly after fish removal.Total phosphorus was positively related to particulate phosphorus.Chl.a also increased in the concentration after fish removal.However, changes in disolved phosphorus concentration were not significant,and concentration of soluble reactive phosphorus was very low both before and after fish removal.Based on the mass balance of input and output of lakes,and the water quality investigation data from May,2007 to December,2008.the present study constructed the algae-type and macrophyte-type water quality forecasting models of Huizhou West Lake.At last,the changes of water quality of Huizhou West Lake in future decade were predicted.The forecasting results from the macrophyte-type model demonstrated that external nutrient loading and the amount of nutrient assimilated by macrophyte would be equal when the covering rate of macrophyte reached 40%or above,and then the concentration of nutrients would decend and reach to a constant,so the water quality could keep in a clear state,which revealed that macrophytes have strong effects on lake restoration.In all,this present study can provide scientific references for Huizhou West Lake to effectively avoid further deterioration of water quality,and maintain a health state of lake ecosystems.