Evaluation And Application Of Ecological Health Of Small Watershed Based On Entropy Catastrophe Progression Method

With the rapid development of social economy,people's development and utilization of natural resources in the river basin has been deepened.However,due to the over pursuit of economic indicators and the lack of attention to the natural environment and natural resources,the natural environment in the river basin has deteriorated,resulting in problems such as river disconnection,water pollution,water and soil erosion,etc.,and the ecological and social functions of the river cannot be played normally,which is not conducive to the river basin Sustainable development.In order to study the factors affecting the ecological health of small watershed and provide solutions for the construction of ecological health of the watershed,a comprehensive evaluation model of small watershed health evaluation system and catastrophe progression method is constructed based on the concept of watershed health.The main work and research results are as follows:(1)Based on the basic theory of watershed health,combined with the actual situation of the study area,this paper constructs a small watershed ecological health evaluation system based on the northern region from three aspects of water resources,ecological environment,society and economy,with a total of 20 indicators.(2)By comparing the advantages and disadvantages of different evaluation methods,the catastrophe progression method is selected to evaluate the health of small watershed comprehensively.Catastrophe progression method is based on catastrophe theory and fuzzy mathematics.It calculates the quantitative value of each index by normalization formula,and finally gets the total membership value of the target layer.Considering the relative importance of the index,the catastrophe series method is suitable for comprehensive evaluation of watershed health.In order to avoid the subjectivity of index ranking,entropy method is introduced to test the index ranking,which increases the scientificity of the evaluation system.(3)According to the specific situation of Xinmi City in the study area,the entropy method catastrophe progression method model is applied and analyzed.From the perspective of the overall ecological health of the basin,except for the good health in 2012 and 2015,the other years are good,and the overall trend is good.Based on the analysis of ecological health problems in Xinmi small watershed,the rationality and feasibility of entropy method catastrophe progression method evaluation system are tested,and corresponding suggestions and measures are put forward according to the results.