| Rivers are an important part of life on Earth and are the basis for the survival and development of human beings.However,in recent years,the rapid development of human society and the over-exploitation and over-utilization of water resources have made river health problems more and more serious,and the degradation of global river ecosystems has seriously affected the development of human society.Miyun reservoir is an important surface water source of the capital city,and its ecological health is related to the smooth operation of the city,the citizens’ peace of mind and the sustainable development of economy and society,and plays an important role in ensuring the safety of water sources.The health of the White River and Tidal River studied in this paper greatly affects the health of the Miyun reservoir.Conducting a health evaluation study of the White River and Tidal River is of great strategic importance to grasp the health of the two rivers,and then take effective restoration and management measures to ensure the water safety of the Miyun reservoir.The conclusions of this study are as follows.(1)Taking into account the ecological environment and social expectations of the existing watersheds on the Miyun Reservoir,the definition of the health of the Tidal River and White River is determined: to ensure the health of the two rivers to the greatest extent possible,so that the natural ecological functions can be well performed,to meet the needs of normal development of human society as far as possible,and to make the development and use of the rivers to form a sustainable development state.(2)A total of 16 indicators at five levels-river hydrology,water quality,river geomorphology,biological status and social service function-were selected to construct a health evaluation system for the Tidal River and White River,and to evaluate the health of the two rivers.(3)The river’s health is classified into five levels: "ideal condition","healthy","subhealth","unhealthy" and "sick",and the evaluation criteria for each evaluation index in the evaluation system are defined,and a score is assigned to each health level.(4)The improved hierarchical analysis and fuzzy comprehensive evaluation method were combined to construct the fuzzy hierarchical comprehensive evaluation model,and the MATLAB programming language was used to calculate the model.It was concluded that the White River scored 86.92 and the Tidal River scored 88.3,and the health of the cross-sections and the overall health of the White River and Tidal River were "ideal contdition",but the biological status of the two rivers and the health of the river hydrological index of the White River were lower.(5)Based on the actual conditions and evaluation results of the White and Tidal Rivers,five measures were proposed for restoration and rehabilitation. |
