黄土高原典型脆弱区生态安全多尺度评价

Multi-scale ecological security evaluation of typical fragile areas in Loess Plateau

区域生态安全目前受到广泛重视,生态脆弱区的生态安全评价及驱动因子研究尤为重要.以黄土高原生态脆弱区为研究对象,从市域和县域两个尺度上,分析案例区的生态安全驱动指标,评价其生态安全状况.选择了榆林市和横山县两个行政单元,针对区域特征,构建了不同尺度上的生态安全指标体系,利用层次分析法,对不同尺度上生态安全的空间分异进行了研究.结果表明,榆林市12个县的生态安全水平存在一定程度的差异,基本上是东北低,西南高.横山县总体也是北部、东北部生态安全水平低,而西南部高生态安全水平在不同尺度上存在着差异.不同尺度上气候、地貌因子所占的权重不大,而人类干扰因子所占的权重较大.

Regional ecological security has been paid more and more attention, and it＇ s of special significance to study the ecological security and its driving factors in ecological fragile areas. In this paper, the ecological security and its driving factors in typical fragile regions in Loess Plateau were analyzed at district and county scales. Yulin District and Hengshan County were taken as the cases, and ecological security index system was constructed to assess the security levels of the two regions. By using AHP method, the spatial differentiation of ecological security at different scales was studied, and the results showed that there existed differences among the twelve counties in Yulin District, with the security level being generally higher in southwest and lower in northeast. Similar tendency was observed in Hengshan County, with the security level being lower in north and northeast, and varying among different scales in southwest. Climate and topography were the weak driving forces, while human disturbances had great influence on ecological security.