三峡库区县域景观生态安全格局识别与功能分区——以奉节县为例

Identification of ecological security patterns for county-level landscapes and function division of the Three Gorges Reservoir Area: A case in Fengjie

景观格局优化是景观生态学中的热点和难点问题,三峡库区作为长江中上游地区生态纽带,其生态安全问题更是成为重中之重。本文选择奉节县为研究区域,在GIS技术支持下对2012年景观类型图进行处理,选取土地利用、地形位指数及土壤侵蚀等阻力因子构建最小耗费距离模型,对研究区内景观生态安全格局进行识别并进行功能分区。本文依据最小耗费阻力面,构建生态"源"地、生态廊道和战略点等景观格局组分,加强和完善生态网络的空间连通性,以提高景观生态格局稳定性及完善生态功能分区。根据耗费阻力突变点,将研究区划分成水源涵养区、生态缓冲区、生态敏感区、生产生活区4个功能区,各区占地百分比分别为36.74%、24.16%、15.48%和23.62%,同时综合考虑自然因素和社会经济因素,模拟建设用地的扩张,为城市扩张规划提供合理依据。

Landscape pattern optimization is popular yet difficult in landscape ecology. The eco- logical safety of the three Gorges Reservoir region, which is the ecological link between the upper and middle reaches of Yangtze River, becomes a top priority. This paper selects Fengjie County as the research region and builds the least-cost distance model to study the landscape ecological security pattern and function division in the research region by considering land use, topographic index, and soil erosion as the resistance factors, with support of GIS technology to deal with land- scape map in 2012. In order to enhance the stability of landscape ecological pattern and improve the ecological functional division, this paper constructs the landscape pattern components consis- ting of ecological sources, ecological corridors and strategic points based on the least-cost resist- ance surface to strengthen and improve the spatial connectivity of ecological network. According to the cost resistance mutation point, the research region is divided into four functional areas inclu- ding water conservation area, ecological buffer area, ecological sensitive area, production and living area, and the proportions of each area are 36.74%, 24.16%, 15.48% and 23.62%, re- spectively. At the same time, the expansion of construction land is simulated by integrating the natural and social economic factors so as to provide a reasonable basis for the planning of urban expansion.