Study On Water Environment Quality Evaluation Of Shuangxi Reservoir

It is very important for environmental protection work to protect the environment of the drinking water source region. Whether do environmental protection of the drinking water source region well or not, concerns the people's life health directly, concerns the normal and persistent developing of national economy, concerns the stability of society. Do environmental protection of the drinking water source region well is of important meaning.A case study of Shuangxi Reservoir was studied in this article.It is based on the investigating and researching on the spot,we assess the pollution source by the method of pollutant loading in equivalent standard,then the gray decision making-comprehensive index assessment method was developed after the deep analysis on the gray decision-making assessment method and comprehensive index assessment method.This developed assessment model has been used in the water environmental quality assessment in Shuangxi Reservoir,and appraise the eutrophication status.Further more,the water environmental capacity of Shuangxi Reservoir was primarily calculated,and presents the relevant countermeasures for controlling pollution in order to protect drinking water source,futher improve water quality and provide scientific foundation for optimizing water resources management.The main results were as follows:1,The point sources pollution and non-point source pollution are exist synchronously in the catchment area of Shuangxi Reservoir,the non-point source is larger than life-point source pollution in cities and towns and non-point source is main affecting factor for the water environment of Shuangxi Reservoir. TN takes the first place among the pollutants;TP takes the first place among the pollutants discharge in equivalent standard,accounting for 79.56%,so the environmental quality of the research area is controlled by TN and TP, the reason is that the non-point pollutants from the countryside contains large amount of TN and TP.2,Through comparision between the gray decision-making assessment method and the gray decision making-comprehensive index assessment method,it was found that the latter has more advantages such as its higher sensitiveness and accuracy,the assessment results reflect the dynamic change trend of water environmental quality more objectively.3,The gray decision making-comprehensive index assessment method has been used in the water environmental quality assessment in Shuangxi Reservoir. Through assessment,it can be concluded that the water quality in Shuangxi Reservoir was better, The gray decision making-comprehensive index between 1.5126 and 1.5851 in Rongxian section, The gray decision making-comprehensive index between 1.5082 and 1.7185 in Guilin qiao section; the water quality was best in low water period,slack water period next,the flush water period was worst; the water quality in Guilin qiao section is better than that in Rongxian section.4,The reservoir has a certain degree of eutrophication and the eutrophication value between 20 and 40.,belonging to moderate eutrophication. The eutrophication value in the flush water period is maximal,the slack water period next, the low water period is minimum,the reason is that large amount of Agricultural non-point pollutants enter reservoir in the flush water period, Agricultural non-point pollutants decrease in the slack water period or the low water period ,so water quality in the slack water period or the low water period is better comparatively.5,through the water environmental capacity calculation,we can see TP,TN whose receiving pollution capacities exceed their water environmental capacities so their quantity should be cut,TP's quantity should be cut the amount of 124.89 t/a, TN's quantity should be cut the amount of 565.31 t/a; COD whose receiving pollution capacity did not exceed its water environmental capacity,its saturation is 33.83%,residual receiving pollution capacities is 432.56t/a.6,we should be focus on the following points to carry out prevention and control work to solve the pollution problems in reservoir. Strengthen the manage- ment of pollution prevention and control for the drinking water sources; Pollution prevention and control measures in the reservoir area; ecological restoration measure in the reservoir area; Strengthen publicity and education, and raise the people's awareness to protect the environment.