Evaluation And Correlation Analysis Of Temporal And Spatial Changes Of Ecological Vulnerability Based On VSD Modeland Analytic-Hierarchy Process-Entropy Method

This paper describes the current situation and progress of ecological vulnerability research,ecological vulnerability research models and methods.Using geographic information system and remote sensing technology to establish an ecological vulnerability evaluation index system based on VSD model combined with hierarchical analysis method and entropy weight method to make a comprehensive evaluation and analysis of ecological vulnerability in the study area.The following results are obtained from the investigation and analysis of the results of this paper:(1)Based on the high-resolution multi-temporal and multi-wavelength remote sensing satellite images,this paper establishes a comprehensive ecological vulnerability evaluation index system,which can evaluate the ecological vulnerability of Suzhou section of the Grand Canal of China and related analysis more scientifically on the basis of multiple data analysis,ensure the timeliness and reliability of the results,and provide a more reliable basis for The evaluation of the ecological vulnerability of the Suzhou section of the China Grand Canal is based on multiple data analysis.(2)In the comprehensive evaluation of the ecological and environmental vulnerability of the Suzhou section of the Grand Canal,the potentially vulnerable and slightly vulnerable areas together accounted for 62.63% of the total area in 2008,and gradually increased with time to 68.80% in 2018,mainly in the middle and lower reaches of the Suzhou section;the very vulnerable and extremely vulnerable areas were less distributed,and their population and industries gradually shifted to the slightly vulnerable areas.The distribution of very vulnerable areas and extremely vulnerable areas is relatively small,and their population and industries are gradually shifting to the slightly vulnerable areas,with the total proportion decreasing from22.11% in 2008 to 15.61% in 2018,and the main distribution area shifting from the upper reaches of the Suzhou section to the middle reaches;the fluctuation of the generally vulnerable areas is less obvious,with the proportion increasing from14.91% in 2008 to 15.60% in 2018,and the overall ecological vulnerability has experienced a trend of first decreasing and then rebounding.(3)The overall ecological vulnerability of the Suzhou section of the China Grand Canal has improved during 2008-2018.The pattern of ecological vulnerability shows that the downstream is better than the midstream is better than the upstream.The improvement of ecological fragility in the Suzhou section of the China Canal is relatively good,with an improvement rate of 37.09%,37.93% and 24.89% in the ecologically fragile and degraded areas.The ecological improvement zone is mainly the Grade I improvement zone,accounting for 13.31% of the total area of the study area,while the ecological degradation zone is mainly the Grade I and Grade II degradation zone,accounting for 9.26% and 9.54% of the total area of the study area respectively.The upstream area of the Suzhou section of the China Grand Canal region is a key area for future ecological vulnerability planning and management.