城市生态网络空间评价及其格局优化

合理的城市生态网络空间格局对于保障城市生态环境可持续发展具有重要意义。以哈尔滨中心城区为研究区,基于景观生态学"斑块-廊道-基质"理论,识别研究区生态源、生态廊道、生态节点和生态基质,分析生态网络连接度强弱的空间分布情况,运用GIS技术和CA-Marcov模型对生态网络格局进行模拟优化。研究结果表明:(1)研究区内部生态源较外部生态源与外界联系较密切;周边地区生态源或生态节点与生态廊道连接数目较少;中北部与西南部生态廊道连接度较差,东部生态廊道连接度处于中等水平,中部个别生态廊道连接度较好;转入的大型生态用地大片集中,转入的小型生态用地零星分布。(2)优化后的生态源地在东西方向与南北方向形成集中连片态势,大型生态源地间彼此连接程度较高;大型生态源之间,以及大型生态源与小型生态源之间构成大型生态廊道,是研究区内主要生态廊道网络;研究区小型生态源之间构成小型生态廊道,是研究区内次要生态廊道网络;研究区周边及研究区中心处60%的区域为生态节点盲区,应加强生态节点盲区生态建设;新增加的大部分生态用地,主要集中分布在水域生态源地周边,还有部分分布在绿地生态源地和风景区生态源地周边,其余少量新增加的生态用地零星分布在林地生态源地周边。研究成果为中心城区尺度的生态环境保护和城市规划提供科学的依据。

Analysis of urban ecological network space and optimization of ecological network pattern

An optimized urban ecological network space pattern boasts of great significance for the sustainable development of urban ecological environment. The present work selected the center of Harbin city as the research area and adopted the "patch-corridor-matrix" theory to identify the ecological source, ecological corridor, ecological node, and ecological matrix in the research area and analyze the spatial distribution as well as the strength and weakness of the ecological network connectivity. Additionally, the GIS technique and CA-Marcov model were applied to a simulation and optimization of the ecological network pattern. The research results indicated that (1) the ecological source in the research area, compared with an external counterpart, maintained a closer contact with the outside world; only a small number of ecological sources or ecological nodes in the surrounding area were connected with the ecological corridors. The connectivity of ecological corridors mid-north and southwest of the study area was poor, that in the east remained at a medium level, and connectivity of ecological corridors. in the middle was good. The distribution of transferred-in large ecological land in the study area was concentrated while the distribution of transferred-in small ecological land in the counterpart was sporadic. (2) An optimized ecological source displayed a trend of concentrated distribution in the west-east direction and the north-south direction, and the connectivity between large ecological sources was relatively high. In the research area, large ecological corridors that formed between large ecological sources and between large and small ecological sources constituted the major ecological corridor network, while small ecological corridors that formed between small ecological sources constituted the minor ecological corridor network. The area around the research area and 60% of the center of the research area was a blind zone of ecological nodes where ecological construction should be enhanced significantly. Newly increased ecological lands were distributed mainly around water bodies, secondarily around greenbelt and scenic areas, and sporadically around forests. The research results provide a scientific foundation for ecological environment protection and urban planning for the central part of the city.