基于MCR的建设用地扩展边界划定研究

在生态文明建设背景下，科学划定建设用地扩展边界是提高城镇化质量、协调人地关系、改善城市生态环境的关键。基于最小累计阻力模型(MCR)，将建成区和生态保护用地作为两类扩展源，通过构建自然、区位、环境和政策4个阻力因子体系，采用层次分析法(AHP)获取各个因子阻力系数，得到两类用地扩展的最小累计阻力值，根据阻力差值划分适宜性分区，并利用Hydrology扩展模块确定建设用地适宜扩展路径和隔离带。结果表明：(1) 越靠近扩展源，其阻力值越小，建设用地源与生态用地源由于空间分布不一致，各阻力值之间差异较大；(2) 基于MCR模型对两类用地扩展的阻力面差值进行建设用地适宜性划分，可分为重点建设区(65 771.64 km²)、优化建设区(51 103.28 km²)、限制建设区(21 001.54 km²)、禁止建设区(17 150.01 km²)和生态恢复区(11 894.70 km²)，不同适宜性分区对土地开发建设的要求不一样；(3) 应用Hydrology扩展模块得到的“谷线”可引导建设用地优化开发，避免盲目的“摊大饼”式蔓延格局； “脊线”可控制建设用地扩展的隔离带，从而打破适宜性区域集中连片的扩展态势。研究结果可为建设用地的科学规划和合理布局提供建议，促进城市建设和环境保护的协同发展。

Study of Extended Boundary Division of Construction Land Based on MCR

Under the background of ecological civilization construction, delimiting the boundary of construction land scientifically is the key to enhance the quality of urbanization, coordinate the relationship between people and land, and improve the urban ecological environment. This paper takes the built-up areas and ecological protection lands as two types of expansion sources based on the MCR model, constructing four resistance factor systems of nature, location, environment and policy, applying AHP to calculate the resistance coefficient of each factor, then dividing the appropriate partition of construction land according to the minimum resistance difference which obtained by the two types land expansion, and using Hydrology expansion module to determine the appropriate expansion path and isolation zone for construction land. The results showed that: (1) The closer to the extended source, the smaller the resistance valueis. The difference between the resistance values is large due to the inconsistent spatial distribution of the construction land and ecological land source. （2) The suitability of construction land for the resistance difference of the two types land expansion based on MCR model can be divided into key construction area (65 771.64 km²), optimization construction area (51 103.28 km²), restricted construction area (21 001.54 km²), and prohibited construction area (17 150.01 km²) and ecological restoration area (11 894.70 km²), different suitability divisions have different requirements for land development and construction respectively. (3) The “valley line” obtained by the Hydrology guides the optimization of development of construction land, avoids the blind “spreading pie” type of spread pattern, and the “ridge line” obtained by the Hydrology controls the expansion of the construction land, breaking the concentration of contiguous areas of suitability. The results can provide suggestions for the scientific planning and rational layout of construction land, and promote the coordinated development of urban development and environmental protection.