Ecological Vulnerability Assessment Based On The Combination Of CRITIC And Analytic Hierarchy Process

In the protection system of our country’s natural ecosystem,nature reserves play a central role and are of great significance in maintaining the regional ecology and the sustainable development of human beings.The East Dongting Lake National Nature Reserve has extensive wetlands and good natural conditions,but it is also vulnerable to irreversible effects.Therefore,a comprehensive assessment of the ecological fragility of the reserve is of great significance to the further planning and management of the reserve.Taking the East Dongting Lake Nature Reserve as the research area,we use remote sensing image data,DEM data,meteorological data and socioeconomic data to construct an evaluation index system.At the same time,the evaluation method was improved to comprehensively evaluate and analyze the distribution and changes of ecological vulnerability in the study area from 2013 to 2017.The main results achieved are as follows:(1)The index system of ecological vulnerability assessment was established.Taking into account the natural geographical and social conditions of the reserve,we selected 18 index factors,based on the " sensitivity-resilience-pressure "(SRP)conceptual model.These factors include topography,weather,landscape,ground surface,and human activities.At the same time,we introduced objective remote sensing indexes instead of qualitative assignments to deal with soilrelated indexes.Finally,an evaluation index system for the ecological vulnerability of the East Dongting Lake Reserve was constructed,which can comprehensively evaluate the ecological vulnerability of the study area.(2)Ecological vulnerability assessment through the coupling of subjective and objective weights.In this paper,the subjective weight was obtained by the improved principal component analysis method,and the objective weight calculated by the objective CRITIC method.Then,the comprehensive weight of each index factor was obtained by coupling subjective and objective weights according to the principle of minimum discrimination.Finally,according to the index factor data and weight results,the ecological vulnerability index was calculated,and the final ecological vulnerability distribution result was obtained.It can be seen from the results of vulnerability distribution that the effects of related governance and protection measures in the protected area are relatively obvious.However,due to the social and economic development of Yueyang District,the external pressure on the ecological environment continues to increase,resulting in an increase in the ecological vulnerability index of some areas.(3)Comprehensive analysis of ecological vulnerability evaluation results.We analyzed the evaluation results quantitatively and spatially,and explored the driving forces of ecological vulnerability of the reserve based on principal component analysis.The results show that the ecological vulnerability in the study area is mainly affected by human activities,followed by the natural primitive conditions.In addition,by using the CA-Markov model,we predicted the ecological vulnerability of the study area in 2021,and the results showed that the protected area was in a relatively stable ecological state.Therefore,the zoning functional planning of the reserve needs to continue to be strictly implemented.At the same time,we need to protect the land cover of the reserve,and human activities should also be strictly controlled and rationally developed and utilized.