[Spatial-temporal Evolution of Ecological Vulnerability in Beijing-Tianjin-Hebei Region Based on PSRM Model]

As one of the three major urban agglomerations in China, the Beijing-Tianjin-Hebei Region has strong economic strength but its ecological fragility is very prominent. To pursue the comprehensive development of economy and ecology, it is very important to analyze the ecological environment in the Beijing-Tianjin-Hebei Region. Here, the Beijing-Tianjin-Hebei Region was selected as the research area, and 19 indicators were selected to construct an evolution system based on the PSRM model. The temporal and spatial evolution characteristics of ecological vulnerability in the Beijing-Tianjin-Hebei Region were explored by combining the order relation method, CRITIC method, Theil index, and hot spot analysis, and the influencing factors were calculated via geographic detector. The results showed that:① the ecological vulnerability first increased and then decreased in the Beijing-Tianjin-Hebei Region. The vulnerable areas showed a northeast-southwest trend, and the ecological environment in the northeast and southwest regions was better than that in the central and southern regions. The area of slight vulnerability in 2014 increased by 6803.01 km² compared with that in 2009. The area of mild vulnerability decreased by 130.41 km², and the area of moderate vulnerability decreased by 26537.31 km² compared with that in 2009. The areas of severe and extremely vulnerable status increased by 19512.9 km² and 351.81 km², respectively, compared with those in 2009. The habitat situation in the Beijing-Tianjin-Hebei Region improved significantly from 2014 to 2019. Compared with that in 2014, the areas of mild, moderate, severe, and extremely vulnerable decreased by 2248.29 km², 2220.21 km², 7988.67 km², and 55.98 km², respectively. The light area increased by 12513.15 km² compared with that in 2014. ② According to the calculation results of the Theil index, the spatial correlation degree of ecological vulnerability in the Beijing-Tianjin-Hebei Region exhibited a V-shaped fluctuation, and the spatial pattern of the cold and hot areas was predominantly consistent with that of the vulnerability. ③ Biological abundance, PM₁₀, and the human disturbance index had a significant influence on the spatial differentiation of ecological vulnerability in the Beijing-Tianjin-Hebei Region. Based on the results of ecological vulnerability analysis, some suggestions on the ecological environment and sustainable development in the Beijing-Tianjin-Hebei Region were proposed.