Constructing ecological security pattern and identifying ecological important areas are the focus of current research on regional ecological security. With Ningbo City as a case study area, we identified ecological sources by remote sensing ecological index, the ecological corridors and pinch point by circuit theory model, and the minimum spanning tree and cuts by graph theory algorithm. The results showed that there were 203 ecological sources in Ningbo, and that the main type of land cover was forest, including a small amount of paddy fields and flooded vegetation. There were 368 ecological corridors with a total length of 573.42 km, being dense in the southwest and sparse in the northeast. There were 91 ecological pinch points, which mainly distributed between coastal areas and closely related ecological sources. According to current situation, we put forward the optimization strategy with 187 primary corridors, 181 secondary corridors, 50 ecological restoration priority areas and 59 long-term ecological restoration areas. The optimization strategy combined with graph theory and circuit theory model would provide a refe-rence for the constructing of ecological security pattern.
构建生态安全格局、识别生态重要区域是目前区域生态安全研究的重点。本研究以宁波市为例,利用遥感生态指数识别生态源地,利用电路理论模型识别生态廊道和生态夹点,利用图论算法识别最小生成树和割边。结果表明: 宁波市共有生态源地203处,土地覆被类型以林地为主,也包括少量的水田和水淹植被;生态廊道共368条,总长度为573.42 km,整体呈西南密、东北疏的趋势;生态夹点91处,夹点主要分布在海涂区域和联系紧密的生态源地之间。根据现状提出优化策略,确定一级廊道187条,二级廊道181条,生态修复优先区50处,远期生态修复区 59处。结合图论与电路理论模型的优化策略为生态安全格局的构建提供了科学依据。.
Keywords: circuit theory; ecological security pattern; graph theory; remote sensing ecological index.