The Research On Evaluation And Prevention Of Water Environment In Xiang River Valley

With the development of industrialization and urbanization, water pollution especially the river valley water pollution has already become a main environmental problem which restricts social economic development and urgently need to be controlled from headstream , from the programming establishment and the implement process. Therefore , It has vitally academic and realistic meaning for sustainable utilization of water resource in watershed and sustainable development of society economy that the new thoughts and methods for resolving the valley water pollution are explored.In this paper, a pilot study on the water pollution control of Xiang river valley in Hunan has been made, based on the theories and techniques of many subjects, after summing and analyzing the most researches around the foreign and domestic. The main contents and results of this paper are as follows:1) Based on the investigation of source pollution and the evaluating for the current quality of water in watershed in 2005, the main problems of water environment and the actuality of water quality are analyzed by the folded map method and the fuzzy mathematics method. The result shows, there are serious industrial and living pollution in xiang river valley, the integrative evaluating results of various statistical index are over fifths grade of water quality , and the main index are COD_cr Gr,As ,the next index are NH3-N and Cr.Concretely ,the main superscale is COD_cr in four cross sections of Greenheart harbor,Qiaokou,Jianglongtan and Xiangzikou, but heavy metal in Toushan,Ao'zhousXiawan,Yijiawan. Apparently, the river has been polluted seriously and mostly parts of the river can't satisfy corresponding function need.2)Based on analysis the social economic development with numerical model, pollutant discharge total quantity in the programming period in the Xiangjiang River basin is forecasted . At the same time , the cut quantity of pollutions is figured out according to environmental quality requirement of watershed of the eleventh five-year environmental programming .By the predictive parsing, in 2010 industrial and living pollutant discharge total quantity is 2,791,966,000 tons,thereinto ,COD discharge total quantity is 248,900 tons . There will be 43,800 tons' COD,2,200 tons' NH3-N,10.7 tons'Cr and 57.84 tons'As to be cut according to programming request.3) An excellent allotment is carried on between mentioned major sectors with the large-scale system multistage hierarchical decomposition coordinated optimization model , The calculated result indicated that COD cut quantity of each major sector in 2010 , that is , the cut quantity of chemical waste water is 2,183 tons, the cut quantity of metallurgy waste water is 4,053 tons , the cut quantity of petroleum waste water is 1.74 tons,the cut quantity of paper making waste water is 453 tons, the cut quantity of food waste water is 62.3 tons, the cut quantity of life waste water is 37097.7 tons.4)Priority project prevention measures and the integrated control measures are Proposed to solve the Xiangjiang River basin water pollution question on the basis of optimized assignment's foundation. The important environmental protection project includes: Industrial sewage processing project, sanitary sewage processing project, heavy metal pollution government project.