基于元胞自动机模拟城市扩张下的绿色基础设施布局演变与内涝风险评估——以武汉市为例

Evolution of Green Infrastructure Layout and Waterlogging Risk Assessment Based on Cellular Automata Simulation of Urban Expansion:A Case Study of Wuhan City

武汉作为中国中部地区城镇化发展最为迅速的城市之一,提供重要生态系统服务功能的绿色基础设施面临建设用地扩张下的空间置换、总量缩减、结构破碎等问题。以武汉市绿色基础设施雨洪调蓄功能为切入点,通过遥感影像解译结合地形、土地利用等数据对武汉市域内的绿色基础设施进行空间格局及水文区位分析;通过构建模拟城市扩张的元胞自动机模型,整合城镇建设用地增长的发展引导约束条件与空间控制约束条件作为运算规则,计算转换概率来模拟城市的扩张;以此分析城市扩张所带来的不同类型绿色基础设施的格局演变与内涝风险。研究发现在城市扩张过程中武汉市水文关键区位敏感性高且易被侵占,建成区将面临雨洪调蓄功能降低所带来的内涝风险。城市扩张与用地的博弈难以避免,绿色基础设施作为发挥城市雨洪调蓄功能的天然载体,其结构完整性对于城市水文过程良性循环起本底作用。保护在城市发展过程中敏感性高、易被侵占且具有关键水文功能的区域,根据风险程度建立多级控制体系,对于武汉市绿色基础设施保护及内涝防治具有重要意义。

Wuhan is one of the cities with the fastest urbanization development progress in the middle area of China.The green infrastructure that provides important ecosystem services is facing problems such as space replacement,total reduction,and structural fragmentation under the expansion of built areas.Starting from the stormwater regulation and storage function of green infrastructure,this paper analyzes the spatial patterns and hydrological locations of green infrastructure in Wuhan with data of topography,land use type,interpreted remote sensing images,etc.To simulate urban expansion,the paper calculates the transformation probability to construct a cellular automaton model by integrating the development guidance and spatial control constraints of the growth of built areas as operating rules.The pattern evolution and waterlogging risks of various green infrastructures caused by urban expansion are analyzed.It disclosed that the key hydrological locations in Wuhan are sensitive and easily occupied in urban expansion,and the built areas face the risk of waterlogging caused by the decline of the regulation and storage function.It is hard to avoid conflicts among different land uses in urban expansion.As a natural carrier of urban stormwater regulation and storage,green infrastructure plays a structural and fundamental role in the benign cycle of the urban hydrological processes.Protecting areas that are highly sensitive,easily occupied,and have key hydrological functions in urban development and establishing a multi-level control system according to the risk level assessed is of great significance for protecting the green infrastructure and preventing waterlogging in Wuhan.