Evaluation of Ecological Vulnerability and Analysis of Its Spatiotemporal Evolution Based on the Fuzzy Comprehensive Evaluation/Catastrophe Progression Method: A Case Study of the Danjiang River Basin (Henan Section)

In recent years, with the implementation of the South-to-North Water Diversion Project, the land use problem and its ecological effects on the Danjiang River Basin (DRB), which is a water source in the project, have become some of the focal points of current research in ecology and environmental science. Selecting the DRB (Henan section) as the study area, an ecological vulnerability evaluation model based on the fuzzy comprehensive evaluation/catastrophe progression method was constructed to evaluate the ecological vulnerability of the study area. The spatiotemporal evolution patterns of ecological vulnerability in the study area were quantitatively analyzed, and the main evolutionary drivers were identified by using GeoDetector. The results showed that: (1) the ecological vulnerability of the DRB (Henan section) was mainly moderate and mild, with areas of 2535.26 km 2 and 2717.33 km 2 , respectively, by 2020, accounting for 30.14% and 32.30%, respectively, of the total area of the basin, with an overall vulnerability distribution characteristic of “low in the north and high in the south”; (2) the ecological vulnerability indices of the DRB (Henan section) in 2000, 2010, and 2020 were 0.56, 0.61, and 0.58, indicating that the ecological quality first decreased and then increased; and (3) the influence of vegetation factors on ecological vulnerability was large, with explanatory power above 4%. The influence of economic pressures and surface factors on ecological vulnerability gradually increased. This study can provide a reference for ecological environmental protection in the water source of the middle route of the South-to-North Water Diversion Project.