基于景观格局的三峡库区生态脆弱性评价

三峡库区是我国的生态环境敏感脆弱区，进行生态脆弱性评价对于掌握其生态脆弱特征和识别生态环境问题具有重要意义. 基于遥感 (RS)和地理信息系统(GIS)空间分析技术，综合考虑景观格局和区域生态2类影响因素，进行三峡库区生态脆弱性评价. 结果表明:①景观类型中，脆弱度由高到低依次为水体、林地、旱地、草地和水田. ②景观破碎度与区域生态脆弱性之间的相关性显著，反映了人类活动对三峡库区生态环境的干扰剧烈. ③三峡库区生态脆弱区可划分为——Ⅰ区(0.171 500≤EVI＜0.191 225)，Ⅱ区(0.191 225≤EVI＜0.210 950)，Ⅲ区(0.210 950≤EVI＜0.230 675)，Ⅳ区(0.230 675≤EVI≤0.250 400). 其中，Ⅲ区和Ⅳ区生态脆弱程度较高，主要分布在水域及其岸边带、高海拔区域和岩溶地貌区域. 特殊的地形地貌是三峡库区生态环境敏感脆弱的重要因素，而人类行为干扰是造成生态环境退化的决定性因子. 

Landscape Pattern-Based Eco-Environment Vulnerability Assessment of Three Gorges Reservoir Area

The Three Gorges Reservoir Area is regarded as a sensitive and vulnerable eco-environment region in China. Assessment of ecological vulnerability is significant to its eco-environmental vulnerability characteristics analysis and problems identification. Based on RS and GIS technology, with consideration of landscape pattern and regional ecology, a vulnerability assessment of the Three Gorges Reservoir Area was conducted. The results show that: ①Vulnerable of landscape types from high to lower is building land, water area, forest land, dry land, grassland and paddy field. ②Significant correlation is found between landscape fragmentation and regional eco-environment vulnerability. This indicates that human activity has produced dramatic interference with the environment. ③ The vulnerable eco-zone of the Three Gorges Reservoir Area can be divided into four subzones, namely, zone Ⅰ (0.171,500≤EVI＜0.191,225), zone Ⅱ (0.191,225≤EVI＜0.210,950), zone Ⅲ (0.210,950≤EVI＜0.230,675) and zone Ⅳ (0.230,675≤EVI≤0.250,400). Zones Ⅲ and Ⅳ, with high vulnerability, are mainly distributed in the water area and its buffer zone, high altitude and steep areas, and the Karst landscape area. Topography is identified as an important element leading to vulnerability; however, human behavior is the decisive factor causing serious degradation of ecological environment.