Analysis Of Water Ecological Environment Characteristics And Evaluation Of Water Ecological Health In Beijing-Tianjin-Hebei Section Of Yongding River

The Yongding River is the largest tributary of the Haihe River Basin,flows through the Beijing-Tianjin-Hebei core area,it plays an important role in the sustainable development of Beijing-Tianjin-Hebei province.At present,there are a series of environmental problems in Yongding River,such as excessive human disturbance,river channel disconnection and ecological environment degradation,It is urgent to study the water ecological health status of Beijing-Tianjin-Hebei section of Yongding River Basin.This study is based on physical,chemical and biological survey data of Beijing-Tianjin-Hebei region in Yongding River Basin,analysis and investigation of regional water environment and water ecology characteristics,identification of key factors affecting water ecology,and take into account the social and human factors,To selected the core indexes by the range test,discriminant ability analysis and correlation analysis of candidate parameters,to build Benthos Biological Integrity System in May2018 level Period,September 2019 wet season(F1)and wet season(F2)by specific value method.Assessment of the region’s water ecological health;To verify the accuracy of the evaluation results,using IEI methods during water level in level Period.The main conclusions are as follows:(1)The identification of key factors in water environment indicates that,TN are the main causes of water pollution.Identification results of key factors of water ecology,The main environmental factors affecting aquatic organisms are TDS、conductivity、redox potential、ammonia nitrogen、TDP and dissolved oxygen.(2)The Yongding River has poor biological integrity compared with the region,The largest proportion of total species was gastropods in three-time benthic sampling,followed by insect or oligo;The diversity and richness of benthos community are superior to other points in Guanting Gorge section.(3)The applicability verification analysis shows that,the evaluation system constructed in this study can accurately reflect the health status of water ecological environment in Yongding River Basin,results of B-IBI health evaluation and IEI health evaluation in level period show that,the trend of the two evaluations is roughly the same,the results of health evaluation in Guanting mountain gorge section are better than those in Yanghe section,the B-IBI evaluation system constructed in this study can effectively reflect the water ecological health of Beijing-Tianjin-Hebei in YongdingRiver.(4)B-IBI evaluation results indicate,the health of the Yongding River basin is poor,there is a high similarity between the evaluation results of level period、wet period(F1)and wet period(F2),the proportion of "healthy" and "better" was less than 50%,In space,it shows that the health condition of Guanting Gorge and Sanggan river is better,and the overall health condition of Yanghe,Yongding Xinhe and Binhai sections is worse,River management and ecological restoration are needed desiderately.