Study on the Spatial-temporal Differentiation and Driving Mechanism of Ecological Vulnerability in Zhangye City

Abstract

Based on the “Sensitivity-Pressure-Resilience” evaluation model, combined with the spatial principal component (SPA) analysis method of GIS, we evaluated the ecological vulnerability of Zhangye City in 2000, 2005 and 2010, then we used geographical detector model to analyse the main driving factors of the ecological vulnerability. The results showed that: 1. The ecological vulnerability of Zhangye City was higher in the West and lower in the East. The average value of ecological vulnerability index was 0.45, which was mild fragile, ecological vulnerability index was the highest in Linze county, and the lowest in Minle county. 2. The overall ecological vulnerability showed a trend of improvement from 2000 to 2010, due to the increase of precipitation in 2005, the ecological vulnerability index was higher than that of 2000 and 2010. 3. Geographical detector results showed that six factors could explain the ecological vulnerability, which ranked as: rainfall in flood season (0.1138) > temperature in high temperature season (0.1116) > elevation (0.0581) > vegetation coverage (0.0532) > topographic relief (0.0411) > biological abundance index (0.0384), and the interaction of the 6 factors had a stronger explanatory power to the ecological vulnerability.