北京市域生态敏感性综合评价

区域生态敏感性评价对于制定区域环境政策,有效进行环境管理具有重要作用.在综述当前生态敏感性评价研究的基础上,综合考虑自然和人文两大类影响因子,构建了反映对水土流失、河流水量水质、土地沙化、泥石流、采矿、路网、濒危物种不同敏感程度的7个指标,运用地理信息系统和遥感技术,综合分析和评价了北京市域生态敏感性程度及其空间分布状况.结果表明,高生态敏感区主要有两类,分别分布于北京东北-西南走向的山区-平原过渡地带和永定河、潮白河、北运河、大石河河岸带,此外,大兴南部也有集中分布.中敏感区除分布于上述高敏感区外围以外,还集中分布于怀柔中部的红螺山、云蒙山地区和门头沟妙峰山地区.不敏感区则主要集中在怀柔、延庆的北部山区,其余地区为低敏感区.敏感性程度的空间变化基本规律是:在山区,从平原-山区过渡地带沿西北方向朝低山区和中山区衰减,在平原,则沿河道两侧向外围衰减.在评价的基础上,尝试提出了环境保育和生态建设的相关对策.

Integrated assessment on ecological sensitivity for Beijing

Regional ecological sensitivity analysis is an effective tool for making regional environmental policies and environmental management. Literature review indicates that more physical-driving factors than human-driving factors are considered in ecological sensitivity assessment. Our future environment will be consisted largely of human-dominated ecosystems; human activities and anthropogenic impacts are especially important in environmental research. In order to integrate both physical and human driving factors, 7 indices, such as water-caused soil erosion, water quantity and quality of rivers, land sandification, debris flow, mining, road density, and the habitats of endangered species, are selected for ecological sensitivity assessment. Using GIS and RS techniques, the author analyzes the ecological sensitivity degrees and their spatial distributions in Beijing. The results show that high ecological sensitivity regions have two types: one is located in the transition-belt from northeastern to southwestern Beijing, which is between plain and mountain regions in Beijing; the other is distributed along the riparian zones of Yongding River, Chaobai River, North Canal, and Dashi River; and the southern parts of Daxing are also included. Moderate-ecological sensitive regions are distributed around the high sensitive regions peripherally and also distributed in mountainous regions of Hongluo, Yunmeng and Miaofeng. None ecological sensitive regions are largely distributed among the northern mountainous regions of Huairou and Yanqing Others are low ecological sensitive regions. Results also show that (1) the ecological sensitivity degrees decrease from the mountain-plain transition-belt to lower and higher mountainous regions along the northwest direction in mountainous region and, (2) decreases from the watercourses to riparian zones along lateral direction in plain. Based on these research results, some environmental conservative strategies are suggested for future ecological management.