基于“质量-风险-需求”框架的武汉市生态安全格局构建

生态安全格局旨在维护景观格局的整体性与生态过程的连续性,以保障城市生态安全.当前的生态源地识别方法缺乏对生态用地退化风险以及人类生态需求的考虑.本研究以武汉市为例,从生态用地质量、生态退化风险以及生态需求3方面计算生态用地的综合价值以识别生态源地,根据土地利用类型和夜间灯光数据构建基本生态阻力面,基于最小累积阻力模型识别潜在生态廊道,基于电路理论识别生态“夹点”,在此基础上构建了“四横三纵十组团”的武汉市生态安全格局.结果表明: 武汉市生态源地面积为2138.2 km²,占市域面积的24.9%,以水域和林地为主,呈组团形态集中分布在市域南北.生态廊道总长度为1222.42 km,其中,水生廊道566.75 km,陆生廊道为655.67 km,水生廊道贯穿市域呈十字型构架,陆生廊道呈环状分布在市域四周,整体上呈现出“四横三纵”的空间格局,生态廊道上共有生态“夹点”44处,以中心城区为核呈环状分布格局.现有保护空间基本落入生态源地范围,证明了识别框架的生态意义,能够为都市区域生态安全格局的构建提供一个量化框架,以指导相关的城市空间规划.

Construction of Wuhan’s ecological security pattern under the “quality-risk-requirement” framework.

The ecological security pattern aims to maintain the integrity of landscape pattern and the continuity of ecological process to ensure urban ecological security. Current ecological source identification methods lack the consideration for ecological land degradation risks and human ecological needs. Taking Wuhan City as an example, the comprehensive value of ecological land was calcula-ted from three aspects, including ecological land quality, ecological degradation risk, and ecological demand to identify ecological source areas. Basic ecological resistance surfaces were constructed based on land use types and nighttime light data. Potential ecological corridors were identified based on the minimum cumulative resistance model. Ecological “pinch points” were recognized based on circuit theory. After that, we built a “four horizontal, three vertical and ten groups” ecological safety pattern in Wuhan. The results showed that the area of ecological land in Wuhan was 2138.2 km², accounting for 24.9% of the total area of the city. These areas were primarily attributed to waters and foress, clustering in the north and south of the city. The total length of ecological corridors was 1222.42 km, with 566.75 km aquatic corridors and 655.67 km land corridors. The aquatic corridors traversed the city area to form a double cross-shaped pattern. The land corridors circularly distributed around the city. Comprehensively, the “four horizontal and three vertical” spatial pattern had appeared. There were a total of 44 ecological pinch points on the ecological corridor, distributed circularly with the central city as the kernel. The extant protection space had almost been included in the identified ecological source area, supporting the ecological significance of the identification framework. It would help to provide a quantitative framework for the construction of ecological secu-rity pattern in the metropolitan area and to guide the relevant urban spatial planning.