Evaluation and prevention countermeasures of water eutrophication of Xianxi Lake in Foshan

The water eutrophication condition of Xianxi Lake is evaluated by using the comprehensive nutrition state index.The results show that Xianxi Lake is between slight and severe eutrophic state at present.Considering water eutrophication,the water quality in the high-flow period is better than that in the mean-flow period while it is the worst in the low-flow period.The water quality of Xianxi Lake changes gradually from a better to a worse state between the upstream and the down stream.Nitrogen and phosphorus are the main factors that cause water eutrophication in Xianxi Lake.Some prevention countermeasures are suggested to solve the problem.