基于景观分析的西安市生态网络构建与优化

生态网络能够连接破碎的生境斑块、增加景观之间的连接性,对应对城市化引发的景观和生态问题具有重要作用。本研究以西安市为例,运用景观格局指数和形态学空间分析等方法在景观格局现状分析的基础上构建了生态网络,并利用重力模型评估了网络结构,最后提出优化策略。结果表明: 西安市景观丰富度较高,但景观状况南北区域差异明显;生态源地主要分布在南部和东部,北部和中部综合阻力值高、连接度较低;生态廊道分布不均,基于水文分析得到的辐射道可以对生态廊道起到补充作用;通过新增生态源地、补设踏脚石及修复断裂点对生态网络进行优化,可改善生态源地分布不均、部分区域生态廊道过长及道路网阻隔等问题,提出的优化策略可为西安市城市规划提供参考。

Construction and optimization of ecological network in Xi'an based on landscape analysis

Ecological network can connect fragmented habitat patches to increase the connectivity among landscapes, which plays an important role to landscapes and ecological problems caused by urbanization. In this study, the ecological networks of Xi'an City were constructed using landscape pattern index and morphological spatial pattern analysis to reveal landscape pattern features. The performance of the network was evaluated with the gravity model to provide an optimization strategy. The landscape richness index was relatively high, with significant differences of landscape patterns between north and south parts. The ecological sources were predominated in the south and east areas, while a higher comprehensive resistance with low connectivity was found in the north and central areas. The ecological corridors were unevenly distributed, with the radiation channels derived from hydrological analysis providing a supplementary role. Furthermore, ecological networks could be optimized by introducing other ecological sources, supplementing stepping stones, and repairing fracture points, to reduce the problems of uneven distribution of ecological sources, the excessively long ecological corridors in local regions, and the obstruction of road networks. Our optimization method provided an optional way to assist urban planning of Xi'an City.