利用图论中最短路算法思想和ArcGIS的空间分析功能,对生境中动物迁徙廊道的识别与构建进行研究。通过对具有不同空间自相关特征的模拟景观进行分析,发现该方法具有较好的适应性,能识别出不同类型模拟景观的廊道。在模拟景观分析的基础上,将该算法应用于长沙市大河西先导区,计算了先导区重要栖息地之间的廊道。研究表明该计算方法提取的生态廊道具有明显的冗余性,充分反映了物种在不同栖息地之间迁徙的需求,具有一定的生态学意义。同时廊道提取结果在一定程度上反映了城市发展对生态系统尤其是生态廊道的胁迫与挤占。通过对廊道空间结构的分析还发现生态廊道存在一定的瓶颈区域,对该区域的生态恢复与重建将对物种多样性的保持起到关键作用。该方法为区域土地管理以及生态环境保护规划提供一定的科学依据。

Ecological corridor,which plays an important role in biodiversity protection,is defined as a stretch of nature mosaic that facilitates the migration of animals.Many GIS software packages use raster cost surface to identify the path of least resistance between source and destination.Limitation of these methods is that only a single path can be identified.However,ecological corridors should be more complicated and more redundant.Many alternative paths with less cost might exist in fact for animals may not choose the optimum path when moving between different habitats.In this paper,a new approach based on Spatial Analyst Tools of ArcGIS using raster data is proposed to identify the redundant routes.Firstly,the resistance cost surface moving from source to adjacent raster was defined.Secondly,the accumulated least-cost raster from both source and destination habitat to any other raster on the cost surface was evaluated.Two accumulated least-cost raster were added by raster calculation module.The value of the added raster is the accumulated least-cost which passed the current raster.Thirdly,the corridor was obtained by extracting the added raster with a certain value.Corridors of six simulated landscape patterns with different spatial autocorrelations were used to assess this procedure.The results showed that the corridors obtained by the procedure include not only the optimum path,but also some sub-optimum paths.The corridor is redundant and fit for describing the migration behavior of animals.Lastly,the identification of the ecological corridors in West Bank Pilot Planning Area of Changsha was taken as an example.The results showed that eleven key habitats existed in the study area.Corridors of twenty adjacent habitat pairs were analyzed.The results showed that all the corridors were of certain width and some of the corridors had furcation or even bypath.However,there are some bottlenecks in some corridors,which become the key zone for the ecological restoration.