Study On The Health Evaluation Of The Qiqihar Section Of The Nenjiang River Based On Basin-water-biological-social Service

The relationship between human beings and rivers has transformed in a number of ways.Primitive people rely on mountains and rivers to use water sources,but also face the risk of river flooding.With the development of human society,people constantly strengthened the control and utilization of rivers,built a large number of dams,reservoirs,hydropower stations and other water conservancy facilities,most of the rivers are polluted by industrial,agricultural and domestic sewage.Due to the changes of river environmental quality and river morphology,people have realized the importance of river protection.Based on the comprehensive investigation of the ecological environment of Qiqihar section of Nenjiang River,this paper analyzes the factors that affect the health of Qiqihar section of Nenjiang River,and constructs a comprehensive evaluation index system that includes hydrology and water resources,aquatic organisms,water quality,physical structure of river banks and social service functions.On this basis,AHP and entropy weight method are comprehensively used to calculate the subjective and objective comprehensive weights to reduce calculation errors,This comprehensive evaluation method is used to evaluate the Qiqihar section of Nenjiang River.Based on the evaluation results,the health influencing factors of the Qiqihar section of Nenjiang River are analyzed,and the corresponding governance countermeasures are proposed.This paper mainly carried out the following work:1.Established a health evaluation index system for the Qiqihar section of the Nenjiang River.Based on the natural conditions,ecosystem characteristics and social service functions of Qiqihar reach of Nenjiang River,an indicator system for ecosystem health assessment was established,including target layer,criterion layer and indicator layer.On this basis,according to the actual situation of Qiqihar section of Nenjiang River,the calculation and scoring standards of 13 evaluation indexes are formulated respectively,and the weight of each index is determined by combining the analytic hierarchy process and entropy weight method,so as to calculate and evaluate the health of Qiqihar section of Nenjiang River.2.Carried out health assessment research.According to the actual situation of Qiqihar section of Nenjiang River,the calculation and scoring standards of 13 evaluation indexes are formulated respectively,and the weight of each index is determined by combining the analytic hierarchy process and entropy weight method,so as to calculate and evaluate the health of Qiqihar section of Nenjiang River.3.Carried out health assessment research.Based on the collected data of water resources,riparian zone,vegetation,aquatic organisms,water conservancy projects and public satisfaction in Qiqihar Section of the Nenjiang River,and combined with field monitoring,a comprehensive evaluation study was conducted on the river health status of the Qiqihar section of the Nenjiang River.The comprehensive evaluation score of the Qiqihar section of the Nenjiang River was72 points,indicating that the whole section was in a sub-health state.The unhealthy characteristics of Qiqihar Section of Nenjiang River include serious soil and water loss,and the aquatic biodiversity of fish and macrobenthic invertebrates needs to be further improved.It is proposed that the main pressure of Qiqihar Section of Nenjiang River health includes the barrier of Nierji Reservoir dam,the discharge of industrial wastewater and domestic sewage,the irregular of water intake,serious soil and water loss,etc.