关键词: 生态脆弱性, 脆弱性域图模型, 时空变化, 驱动要素

Abstract: To identify ecologically vulnerable areas within the territorial space control scope of the Wuxi section of the Grand Canal, we used the vulnerability scoping diagram (VSD) model to establish an evaluation index system with three dimensions, including exposure, sensitivity, and adaptability. Further, we analyzed the spatiotemporal variations of ecological vulnerability in the Wuxi section of the Grand Canal from 2010 to 2020. Current models could not efficiently analyze the gradient of ecological vulnerability in the monitoring district of the Wuxi section of the Grand Canal. Therefore, the principal component analysis (PCA) was implemented with 24 ecological vulnerability indicators to determine the crucial vulnerable items in the monitoring district. The results showed that the proportion of extremely vulnerable areas in the Wuxi section of the Grand Canal decreased to 18.8% from 2010 to 2020. A large proportion shifted from high vulnerability to medium vulnerability. The proportion of low vulnerability areas increased to 21.91%, with an overall decreased vulnerability. Spatially, the ecological vulnerability in the study area was mainly manifested as slight degradation in Huishan District, partial degradation in Binhu District, obvious improvement in Liangxi District and Xishan District, and basic maintenance in Xinwu District. The significant degradation areas of ecological vulnerability as shown by the VSD model were mostly located in the fringes of builtup areas. The change of ecological vulnerability in the monitoring area of Wuxi section of the Grand Canal located in the urban center was not significant, making it difficult to locate vulnerable areas. The reduction of ecosystem exposure and the improvement of maintenance capacity were the main trends in the monitoring area in the past 10 years. As the whole region was in the trend of maintaining or improving the ecological vulnerability, it is difficult for the VSD model to directly reveal the change of the internal vulnerability gradient of the region. In the monitoring district, some areas were not in line with the above-mentioned vulnerability improvement trend. By combining the spatial distribution of five adverse trends in the monitoring district, the overlapping area of the corresponding space of three or more adverse trends and the ecological control area were selected as the candidate area of the riverside ecological area in urgent need of protection. The environment analysis and satellite image interpretation of the riverside ecological area showed that rural regional governance funds were relatively scarce, and that the governance funds were mainly targeted at three major problems: industrial pollution, significant degradation of cropland, orchard and forest patches of non-controlled objects, and the reduction of specific ecological service ability. Accordingly, specific protection measures for the ecologically vulnerable areas were put forward.

Key words: ecological vulnerability, vulnerability scoping diagram (VSD) model, spatiotemporal variation, driving factor