Assessment Of Water Environmental Quality Based On Three Level Functional Zoning Of Water Ecology In Songhua River Basin

After years of research,thezoning studyof the water ecological environment function of the river basinhas become increasingly mature.Songhua river basin is one of the important basins in China,and thezoningofwater ecological environment function has been basically completed.Evaluation of water ecological environment quality in river basin.In addition to the current assessment criteria for hydrochemical factors,the characteristics of water ecological function zoning should also be taken into account.The system should also take into account the social and geographical factors of the river basin.In the three-level zoning of water ecological function in Songhua River basin,26 key sections dispersed in 5 zoning were selected.The monitoring indicators are hydrochemical factors,aquatic organisms and physical habitats.Combined with the research results,a comprehensive evaluation system of water environment quality was established based on the three levels of water ecological function in songhua river basin.The research also carried out a scientific and advantageous test of the method.The results of comprehensive evaluation of water ecology were compared with the evaluationresults of conventional physical-chemical index.There are slight differences in the water quality of the monitoring zoning in the two evaluation methods,but the overall changes in the Songhua River basin reflected by the two methods are basically consistent,showing a certain degree of correlation and consistency.The limit factor is discussed for different functional partition.It is concluded that the comprehensive evaluation system of water ecology established for this study can reflect the quality of water ecology environment more scientifically and accurately.A comprehensive evaluation of the 5-year water ecological environment quality of the Songhua River basin during the period from 2013 to 2017 was conducted.Based on the two dimensions of time and space,the comprehensive evaluationresults of the three-level water zoning in the Songhua River basin in recent 5 years were analyzed.In the past 5 years,the comprehensive evaluation index of water ecology in the Songhua River basin is on the rise and has significant significance.The water quality of each functional zoning in the Songhua River basin shows different trends,but most of them are good,which indicates that the quality of the water ecological environment in the Songhua River basin has gradually improved,and the quality level of water ecological environmenthas changed from mild pollution to good.However,in some areas,there is a poor condition of water ecological environment quality.Based on the results of the calculation and evaluation of each functional zoning,this paper summarizes the existing problems in the characteristics of the Songhua River basin..And the improvement measures and Suggestions are put forward for the management of water ecological environment quality in songhua river basin.