Evaluation On Ecological Health Status Of Yanghe Based On Water Quantity-Water Quality-Biology

River is the cradle of human civilization,which has many functions such as regulating climate,improving the environment,providing water,keeping ecological balance and so on and has remarkably economic,social and ecological benefit.However,with the increase of human activities,the interference in the river and its damage becomes more and more intense,which results in a series of problems such as poor river connection,reduction of water quantity in river channel,deterioration of water quality,reduction of biodiversity and degradation of ecosystem.These problems are not only detrimental to the river healthy,but also affects the sustainable development of human society.At present,China government focuses on the above environment problems,strengthens the construction of ecological civilization,and restorates river eco-environment imperatively,due to the management acquirement of both the river basin and the masses.In this research,Yanghe a typical tributary of northern China was chosen as the typical research catchment.The following studies have been completed:(1)According to the present status of the social and economic development of Yanghe Basin,the serious situation and many problems of the river were analyzed.Then,the effects to Beijing on downstream were evaluated.(2)Based on the basic situation of the Yanghe Basin and the researches on river health at home and abroad,the index system of Yanghe health evaluation was constructed by evaluation indices,evaluation scale,index weight and health grade division.(3)Based on this index system,the monitoring site was setted,field sampling and monitoring scheme were designed and carried out,and data was collected.According to the evaluation standard of grade division,three dimensions(water quantity,water quality and biology)of Yanghe were analyzed.Then,the corresponding heathy scores and grades of different dimension were evaluated.The results show that the health score of water quality,water quality and biological is 2.92,78.9 and 54.2 respectively;and the whole ecological health scoreof Yanghe is 46.2,which shows an unhealthy state.Due to these evaluation results,and the main factors affecting on the river health were illuminated,and some reference suggestions were put forward.The above results can provide related information for the sustainable resources utilization of Yanghe,support for regional decision-making on river protection and ecological restoration,and some references for the river health evaluation in Haihe River Basin and even the northern region.