权衡城市扩张与永久基本农田保护的城市增长边界划定——以武汉市为例

Determining the Urban Growth Boundary by Balancing Urban Expansion and Permanent Basic Farmland Protection:A Case Study of Wuhan

城市增长边界划定是优化城市空间结构和管理格局、增强城市综合承载力的有力手段。然而,由于城市周边的耕地质量较高,城市增长边界与永久基本农田保护在空间上存在显著的冲突。已有的城市增长边界划定研究大多忽略了城市扩张与永久基本农田保护的冲突,不利于城市周边优质耕地的保护。针对这一问题,该文利用土地系统模拟与优化模型(LANDSCAPE),以武汉市为例,开展了权衡城市扩张与永久基本农田保护的城市增长边界划定研究。结果表明:LANDSCAPE模型在城市增长边界划定过程中能够权衡城市扩张与永久基本农田保护,既能满足城市增长的需求,又有效避让了城市周边的优质耕地和重要生态用地,实现了城市扩张与永久基本农田保护的空间协调;该文提出的城市增长边界划定方法可以为快速城市化地区合理划定城市增长边界、实现区域土地资源的合理有效利用提供方法支撑。建议相关部门应同步划定城市增长边界与永久基本农田边界;同时在城市扩张与耕地保护冲突激烈区域设置耕地保护弹性区,并在该弹性区权衡城市扩张与优质耕地保护。

Demarcation of urban growth boundary(UGB) is a powerful means to optimize urban spatial structure and management pattern and enhance the urban comprehensive carrying capacity.However,due to the high quality of cultivated land around the city,there is a significant spatial conflict between the urban growth boundary and permanent basic farmland reserve.The existing delineation of the urban growth boundary mostly neglects the conflict between urban expansion and permanent basic farmland protection,which is not conducive to the protection of high-quality cultivated land around the city.In order to solve this problem,this paper uses land system cellular automata model for potential effects(LANDSCAPE) to study the demarcation of urban growth boundary,which weighs the urban expansion and permanent basic farmland protection in Wuhan.The results show that:1) The LANDSCAPE model can realize the weigh between urban expansion and permanent basic farmland protection in the process of UGB delineation;2)The UGBs demarcated by balancing urban expansion and permanent basic farmland protection can not only meet the demand of urban growth but also effectively avoid the high-quality farmland and important ecological land around the city,and realize the space coordination between urban expansion and permanent basic farmland protection.3)The method of delimiting the urban growth boundary which is proposed in this paper can provide methodological support for rationally delimiting urban growth boundary and realizing the rational and effective use of regional land resources in rapid urbanization areas.According to the result,several suggestions were put forward:First,the planning department should demarcate UGBs and permanent basic farmland boundary simultaneously.Besides,the farmland protection elastic zone should be set up inside these areas,where urban expansion and farmland protection conflicts.And the urban expansion and high-quality farmland protection should be weighed in the elastic zone.