Analysis of limiting factor to eutrophication and its countermeasures in Shahu Lake

To determine the main limiting factor about development of water eutrophication in Shahu Lake,this paper dealt with the relation between algal chlorophyll-a(Chla) and eight environmental factors such as total phosphors(Tp),total nitrogen(TN),water temperature(T),pH,secci-depth(SD) based on the monitoring data in Shahu Lake from 2002 to 2004.The regression statistical method was used to calculate the relation between algal chlorophyll-a and these environmental factors.The results showed that water temperature,Tp and SD were the most significant related factors to algal chlorophyll-a,and water temperature and TP were the limiting factors to eutrophication in Shahu Lake.The results of eutrophication analysis show that internal pollution sources and external pollution sources are the main causes for water eutrophication in Shahu Lake.Especially the water supply from Yellow River and surface runoff are the main external pollution sources.According to the analysis,some countermeasures were given to control the water eutrophication in Shahu Lake finally.