Research On Evaluation Method Of Water Quality Evaluation In Nenjiang Important Provincial Boundary Buffer

Water is a natural resource for human survival.In ancient times,water is considered to be the source of all things.But with the development of science and technology,modern people more and more use of water,water quality of the rivers and lakes of part of the decline,even a threat to people’s living area,water environment has become the object of modern people worry.Under the situation that the water environment pollution is very serious,it is very important to carry out comprehensive control of water pollution and improve water environment evaluation method.This paper mainly expounds the present water quality assessment methods,and using single factor evaluation method,grey correlation analysis,factor analysis and cluster analysis to study the buffer zone of Nenjiang important section"12th Five-Year"（2011-2015）of the water pollution situation.Buffer zone is a special form of water function area of watershed management proposed for the country,the ultimate goal of management is the goal of water quality does not affect the downstream or adjacent provinces（regions）of the water resources demand,this paper focuses on the use of a variety of evaluation methods for comprehensive analysis of provincial water quality buffer,to provide effective technical support for basin analysis assimilative capacity.The results show that the buffer zone of Nenjiang section of important chemical oxygen amount of grey correlation degree is low,the index represents the greatest impact on the buffer zone of Nenjiang basin,is the need for key control index.But as the year goes on,when the water quality of Nenjiang basin overall buffer zone was improved when the correlation of the chemical oxygen demand is also increasing.Combined with the average annual monitoring data of 2014 and 2015,it can be considered that the buffer zone of Nenjiang has begun to strengthen the supervision of the chemical oxygen demand,and take effective measures to reduce emissions of pollutants.Nenjiang section of buffer zone of water 2011-2015 years（except 2013）the comprehensive water quality overall is increasing year by year,the main influencing factors of pollutants are COD_Mn,COD,BOD₅.By cluster analysis,buffer zone of Nenjiang important section can be divided into three categories.The first section is the upstream buffer zone of the section and the national assessment section,including Jia xi village,Jinshe Wan pier and two subsidiary,the optimal water quality;Second kinds of cross section for the middle section of buffer zone,lime pit,mordin,Prosperous village,Ewenki nationality township and Mo Hu ferry;Third kinds of cross section for the downstream buffer zone section,including river,Daan,three Chahe river,the water quality is relatively weak.The buffer zone of the important section in Nenjiang’s most polluted river as an example.The main factors affecting the water quality of the river section are organic pollutants and nutrient enrichment.The cause of the serious pollution of the river section is Gannan County of Qigihar City,the river section where the county agriculture and animal husbandry,animal husbandry and winery and fertilizer plant of the county’s industrial production emissions of organic pollution factors,leading to the river water quality exceed the standard.The innovation of this paper is:The integration of a variety of methods to assess the water quality of river buffer zone,and then through the depth analysis of water quality data,optimize the combination of explicit method,the water quality evaluation results of science.