Research Of Water Quality Prediction And Self-purification Water Demand Of Fenhe River

The severity of the rivers water pollution has aroused widespread attention from all sectors of society.The degree of water quality pollution is not only related to pollutants,but also connected with the transformation of pollutants migration and river water self-purification function.Setting Fenhe River as an example,this paper analyze and evaluate the Fenhe River water quality present situation and influencing factors,and then predict the water quality at time and space scales,the final calculate the demand of self-purification water for each control section,the specific research contents and results are as follows:1.According to the water quality monitoring data among 2004-2013 of two hydro logical stations in the Fenhe River,used the comprehensive index method and Nemerow index method to evaluate the status of the Fenhe River water quality.Results show that the two methods are successfully used to evaluate water quality in Fen River flow stream,theevaluated results of the two methods are showed that Fenhe River water quality is In the stage of a serious pollution,improvement and management water quality in Fenhe River is completely necessary.2.This paper used gray correlation theory to rank the key factors of the cause of the Fenhe River water quality change(the meteorological factors: temperature,relative humidity,rainfall,the non-meteorological factors: runoff,industrial sewage emissions,residents living water).The results showed that:industrial(0.739)> residents(0.710)> temperature(0.705)> runoff(0.688)relative humidity(0.681)>the rainfall(0.641).3.This paper used one dimensional water quality prediction model and GM(1,1)gray prediction model to predict the variations between spatial and temporal in river water quality.Compared with the measured results,prediction model can reflect the Fenhe River section of the spatial and temporal variations of river water quality well.4.Based on water balance method and the flow regulation method,to calculate the different river sections(ErBa,YiTang)self-purification water demand.The results show that :the first approach water requirement for self-purging water of Yi Tang section is 17.54 m~3/s and ErBa is 9.41 m~3/s,and the calculation results accord with the reality;Yi Tang section what meets the ? class water by using flow control method require the flow rate of 42.23 m~3/s,estimated the result has a certain practical reference value.