Dynamic Monitoring of Ecological Vulnerability in the Semi-arid Desert and Steppe Ecological Zone of Northern China Based on RS and Its Driving Mechanism Analysis

Abstract:

Considering the unique geographical conditions (serious soil wind erosion, salinization, desertification and soil water erosion) and extreme climate index (extreme high/low temperature days and extreme precipitation days) in the semi-arid desert and steppe ecological zone of northern China, an evaluation system for the ecological vulnerability was established by introducing the large-scale landscape pattern indexes (Shannon uniformity index and contagion index). Then, the spatial and temporal changes in the ecological vulnerability during the last 13 years were analyzed and discussed. The results showed that the ecological vulnerability over the semi-arid desert and steppe ecological zone of northern China belonged to moderate vulnerability, and showed a decreasing trend from west to east. During 2000-2013, there was a decreasing change trend in ecological vulnerability. In the last 13 years, the temporal and spatial patterns of ecological vulnerability of the semi-arid desert and steppe ecological zone of northern China were significantly affected by GDP density, temperature, precipitation and topography factors. All of these would provide scientific supports for environmental modification and protection in the semi-arid desert and steppe ecological zone of northern China.

Key words:Ecological vulnerability;Temporal and spatial patterns;Salinization;Desertification;Driving mechanism