北方半干旱荒漠草原生态区生态脆弱性变化遥感监测及其驱动机制分析

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

摘要:

针对研究区的生态环境特征（风力侵蚀、沙漠化、盐渍化严重、水力侵蚀严重），引入了大尺度景观格局指数（香农均匀性指数和蔓延度指数）和极端气候指数（极端高温日数、极端低温日数和极端降雨日数），构建了北方半干旱荒漠草原生态区生态脆弱性评价体系，进而分析和探讨了该地区近13年的生态脆弱性时空变化格局和驱动机制。结果表明，北方半干旱荒漠草原生态区的生态脆弱性总体上属于中度脆弱状态，呈现自西向东递减的趋势。2000-2013年，北方半干旱荒漠草原生态区生态脆弱性呈现减小趋势。近13年北方半干旱荒漠草原生态区的生态脆弱性时空变化格局受GDP密度、气温、降水、地形等因子影响显著。这些为北方半干旱荒漠草原生态区的生态环境修复及保护提供重要的科学支撑。

关键词:生态脆弱性;时空格局;盐渍化;沙漠化;驱动机制

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