基于分形模型的城市绿地系统时空进化分析——以上海市中心城区为例

Spatial-Temporal Evolution Analysis of Urban Green Space System Based on Fractal Model:A Case Study of Downtown Shanghai

城市绿地是城市生态空间的重要组成部分,其形态特征及布局结构遵循规律性机制进行演替。基于上海市1983年、1994年和2002年城市绿地系统的规划背景、政策推进及建设成效等,结合形态维模型和聚集维模型,对中心城区绿地进化的多维特征进行定性和定量分析。结果表明:(1)规划引导是影响城市绿地时空进化的关键因素,且具有系统性、阶段性及动态性特征;(2)在发展阶段上,上海市的绿地建设经历了快速发展阶段和质量跃升阶段,趋于"量"到"质"的优化;(3)在绿地空间形态结构上,自组织及演化未达到最优化状态,但形态维数随时间的变化而逐渐降低,绿地空间形态整体趋于整合,系统性增强;(4)在绿地分布格局上,聚集维数先增强后减弱,绿地斑块由分散、割裂状态趋向环廊结合、通达性较好的网络系统结构。

Urban green space is an important part of urban ecological space,and its morphological characteristics and layout structure follow the regular mechanism for succession.Based on the planning background,policy advancement and construction achievements of urban green space system in Shanghai in 1983,1994 and 2002,combined with the morphological dimension model and the aggregate dimension model,qualitative and quantitative analysis of the multi-dimensional characteristics of the green space evolution in the central urban area was carried out.The results show that:(1) Planning guidance is the key factor affecting the spatial and temporal evolution of urban green space,and it has systematic,phased and dynamic characteristics;(2) In the development stage,Shanghai's green space construction has experienced rapid development stage and quality.During the jump phase,it tends to optimize from “quantity" to “quality";(3) Green space,sel&organization and evolution have not reached the optimal state,but the shape dimension gradually decreases with time and the whole tends to be integrated and systematically enhanced;(4) In the distribution pattern of green space,the aggregation dimension first increases and then weakens,and the green space patches are dispersed and split to the ring corridor,and the network structure is better.