基于最小生态用地需求的城市景观生态安全格局研究——以深圳市为例

Based on the theoretical analysis and thus practical application for the key issue of landscape ecology, i.e. the correlation between landscape patterns and ecological processes, the construction of landscape ecological security pattern has become one of the key topics in urban landscape ecology. Taking Shenzhen City as the study case, we plan to analyze the spatial pattern change of ecological lands during 1978-2010 and associated driving forces, with the application of landscape metrics and RS and GIS technologies. Focusing on a certain ecosystem service, we will calculate the minimum requirements for urban ecological lands with different scenarios of urban development. There are two factors that will be considered in assessing the reserving value of urban ecological lands, i.e. the importance and degradation risk of ecological functions. Based on the ecological resistance surface revised by the index of Impervious Surface Area, the key ecological corridors will be identified through the accumulative minimum resistance model. In this project, considering the tradeoffs between the demands for ecological security and urban sprawl, we hope to put forward a new approach to the construction of landscape ecological security pattern, which will contain three parts, i.e. calculating the minimum requirements for urban ecological lands, assessing the reserve value of urban ecological lands, and identifying the key ecological corridors. And this approach is regarded to be more suitable for the actual demanding of sustainable urban development than the traditional ones. Considering the research results will help to enriching the methodology of landscape ecological security pattern theory, and guiding urban planning, the project is of great importance in science and practice.

景观生态安全格局构建是对景观生态学"格局-过程互馈"核心命题的理论解析与实践应用，已成为目前城市景观生态研究重点方向。本项目以快速城市化地区- - 深圳市为研究区，基于景观生态学原理与方法，综合应用野外调查、实地观测、遥感与GIS分析和模型模拟等技术手段，探讨深圳建市以来生态用地格局演变过程及其驱动力，基于特定生态系统服务测算不同社会经济发展情景下城市最小生态用地需求，综合考虑生态功能重要性及退化风险明晰生态用地保留价值，采用不透水表面指数构建生态阻力面，应用最小累积阻力模型识别关键生态廊道，探讨空间优化策略。本项目研究将综合权衡城市地域生态安全保护与建设用地扩张，探索基于"最小生态用地需求测算-现状生态用地保留价值评估-潜在关键生态廊道识别"的城市景观生态安全格局构建途径，以期更为契合当前城市可持续发展现实需求。项目成果对丰富景观生态安全格局理论方法、指导城市规划，具有重要的科学与实践意义。

生态安全格局提供了保障城市生态安全、提升城市可持续性的重要空间途径，是景观生态学格局与功能互馈研究的重点领域、城市景观生态学研究的热点方向。本研究基于遥感影像等多源数据，从城市生态用地格局演变、生态需求识别、生态源地及关键廊道识别等重点方向开展研究。主要研究成果包括：（1）明晰了城市生态用地格局演变基本特征及其人文-自然驱动力。1990-2010年深圳市生态用地数量持续减少，但减少速度放缓、单位面积生态系统服务提升，坡度、距建设用地最小距离是主要驱动力；（2）识别了水生态系统服务视角下的城市最小生态用地需求空间。珠海市2020年城市发展预期规模下生态用地需求总量占全市陆域总面积50.8%，以林地、水田、水域为主，重点分布于海拔25m以上丘陵、低山区域，40%的平原地区纳入需求范畴；（3）提出了更为契合城市发展需要的生态安全格局构建途径。针对生态源地识别单一性的问题，基于“重要性-敏感性-连通性”框架提取了云浮市生态源地；考虑到生态安全格局的构建以提升人类福祉为目标，应重视生态源地的人类需求程度差异，从生态需求角度出发识别了京津冀地区生态源地；关注城市发展过程中的生态用地占用及功能退化，基于生态功能重要性与退化风险筛选深圳市生态源地；鉴于依据地类赋值的阻力面构建会忽略地质灾害对物种迁移的影响，采用地质灾害敏感性修正基本生态阻力面，并基于最小累积阻力模型判定了玉溪市关键生态廊道；面对最小累积阻力模型廊道识别法仅能判定廊道走向的不足，基于信息素量空间格局，采用蚁群算法识别出了北京市生态廊道的宽度与范围；（4）基于生态安全格局构建划定生态红线。设置合适的阈值，基于生态功能分区修正生态安全格局，进而划定了满足相应生态需求的济宁市刚性、弹性生态红线范围。未来将进一步研究生态安全格局的重要阈值设定、有效性评价、多尺度关联与生态过程耦合等关键问题，以期为生态保护与城市发展的协同提供有效的科学指引。