Study on the Effect of Agricultural Non-point Source Pollution to Water Environment of the Ebinur Lake Basin during High Flow Period

Abstract

Sustainable utilization of water resources is the foundation and condition for sustainable socio-economic development.Healthy water environment and adequate pure water is an important guarantee for implementing the sustainable development strategy of China in 21 century.As a water carrier,river is an important component part of surface water resources and plays an important role in regional water environment and economic development.Agricultural non-point source pollution is a ubiquitous environment problem nowadays.It restricts directly the sustainable development of society and economy in the world and has aroused more attention.In this paper,an analytical method of comprehensive pollution index is used to evaluate the water environment quality in the Ebinur Lake Basin,and the distribution and concentrations of various forms of nitrogen and phosphorus in surface water samples collected in May 2008 are analyzed systematically.Through comparing with the standards of water quality category,the result shows that the water quality in the Ebinur Lake Basin during high flow period was polluted moderately.NO-3-N was the main pollutant in the Ebinur Lake Basin,and the concentrations of NO-3-N and TN in the Bortala River were 0.433 mg/L and 3.545 mg/L respectively,which were the highest in all the rivers.This result reveals that agricultural non-point source pollution was the main cause for the pollution of Bortala River,and this was also why the pollutants' concentrations in other rivers were lower than those in it.The concentrations of NH+4-N in the Kuytun River and Jinghe River were 0.251 mg/L and 0.249 mg/L respectively,higher than those in other rivers,which reveals that human activities played a dominant role in polluting the water environment of two rivers.In addition,the total phosphorus and nitrogen concentrations were very high at all the sampling sites,especially along the Bortala River,where the total phosphorus concentration was higher than that of water quality standard V.In conclusion,the water environment quality in the Ebinur Lake Basin has been eutrophicated on the whole.