三峡库区生态屏障区景观格局优化——以重庆市江津区为例

Landscape pattern optimization for ecological barrier in the Three Gorges Reservoir Area:A case study in Jiangjin,Chongqing

三峡库区生态屏障区是全国生态安全体系的重要组成部分,以景观格局优化为切入点构建区域生态安全格局是国内外研究热点。以江津区为例,在GIS的支持下,运用粒度反推法和最小耗费距离模型模拟生态流的空间运动,以确定对区域生态安全有关键意义的景观格局构成要素及空间分布,分别从生态源地、生态廊道和生态节点3个方面构建"点—线—面"空间生态网络,增强区域生态系统的整体性和连通性,为江津区景观格局优化及生态服务功能的提升提供参考。结果表明:(1)200 m粒度时生态源地具有最佳连通性,此时有生态源地10个,总面积约6.06×10~4hm^2,新增生态源地14个,总面积0.01×10~4hm^2。生态廊道22条,生态节点24个;(2)粒度反推法能较好地克服生态源地选择的主观性;(3)最小耗费距离模型能将生态功能和过程有机结合,克服数学模型不能将生态过程空间化表达的弱点。

Ecological barrier in the Three Gorges Reservoir Area is the most important region in national ecological security system. Building regional ecological security pattern by landscape pattern optimization is a hot topic in research worldwide. By adjusting the components of landscape pattern, landscape pattern optimization aims to build point-polyline-polygon ecological space network and enhance the integrity and connectivity of regional ecosystem. In this study, Jiangjin was chosen as a case study area for landscape pattern optimization. With the support of GIS, the map of landscape pattern was derived from the land-use map of 2014. The ecological sources were chosen by granularity inverse method. Ecological corridors and nodes were built by minimum cumulative resistance. The results showed that （1） 200 m was the best grain to connect the ecological source. There were 10 ecological sources （with a total area of 6.06×104 hm2）, 14 new ecological sources （with a total area of 0.01×104 hm2）, 22 ecological corridors and 24 ecological nodes; （2） The granularity inverse method could effectively overcome the subjectivity of choosing ecological sources; （3） minimum cumulative resistance could combine the ecological functions and processes and overcome the weakness of mathematical models that are hard to express spatial ecological processes. This study would provide scientific basis to landscape pattern optimization and the enhancement of ecological service value.