基于空间效率与游憩需求匹配的城市小微绿地布局优化研究——以十堰市主城区为例

Research on Layout Optimization of Urban Micro Green Space Based on the Matching of Space Ef ciency and Recreational Demand:A Case Study on the Main Urban Area of Shiyan City

当下以扩张为主要形式的城市化进程加剧了人地矛盾,这一问题在建设用地困难的城市中尤为突出,小微绿地可以在有限建设面积下填补服务盲点,提供高效的游憩服务。十堰市作为南水北调中线上重要的山地城市,绿地建设受诸多因素限制。本研究从场地可达性、空间服务效率与空间使用效率三个维度构建小微绿地空间效率测度体系,以地块为研究单元,对十堰市小微绿地空间效率进行测度。基于空间效率与游憩需求的匹配结果识别需求点,从碎片化的绿斑与“退二进三”的工业用地中选取潜在小微绿地建设点,以实现最大覆盖范围为目标,综合运用K-Means模型与LA位置分配模型,针对现状“低效率—高需求”地块进行小微绿地选址与布局优化。研究结果表明:(1)在十堰市现状有限小微绿地的覆盖范围下,低效率与较低效率地块数量分别占总数的19.1%与20.2%,大量的服务盲区更是造成了绿地的供需失调;(2)63.45%的地块处于低效率与高需求的矛盾状态,居民的游憩需求无法得到满足。研究通过模型优化,在保持现有绿地布局的基础上,新增113处小微绿地,实现最大范围覆盖城市需求点。对比优化前后的结果表明:(1)空间效率方面,低空间效率地块由46块减少至29块,较高空间效率地块由59块增至138块,高空间效率地块由31块增至101块;(2)空间效率与游憩需求匹配方面,低效率—高需求地块的数量占比由63.45%减少至17.73%,达到预设目标,优化后的布局提升了居民享有小微绿地游憩服务的机会。

Urban sprawl is now paving out the land,which leads to the contradiction between land and man.This problem is particularly prominent in cities where construction land is rugged.Microgreen spaces can reduce unserved zones under limited construction areas and provide effcient recreational services.Shiyan City,a signifcant mountainous city on the middle line of the south-tonorth water diversion project,is restricted by various factors in planning its green spaces.This research establishes evaluation methods for microgreen spaces and takes the block as the research unit to measure the space effciency of microgreen spaces in Shiyan City.Then based on the matching results of space effciency and recreational demand,the demand points are identifed.The potential microgreen space construction points have been selected from the fragmented green spaces and the industries that will suppress from the second industry to the third industry.The k-means and LA location-allocation models are comprehensively operated to optimize the site selection and layout of small and microgreen space for the current“low effciency-high demand”plot to achieve maximum coverage.The research results show that:(1)Under the current limited range of miniature and microgreen spaces in Shiyan City,the number of low-effciency and low-effciency plots accounted for 19.1%and 20.2%of the total,respectively,and a large number of service blind spots caused the supply and demand of green space.(2)63.45%of the plots are in a contradiction between low effciency and high demand,but residents’recreational needs rarely are met.Through model optimization,the study added 113 small and microgreen spaces based on maintaining the existing green space layout to achieve maximum coverage of urban demand points.Comparing the results before and after optimization shows that:(1)In terms of space effciency,the low space effciency plots decreased from 46 to 29,the high space effciency plots increased from 59 to 138,and the high space effciency plots increased from 31 plots.(2)Regarding space effciency and recreational demand matching,the proportion of low effciency-high demand land plots has been reduced from 63.45%to 17.73%,reaching the preset target.The optimized layout improves residents’enjoyment of small and microgreen spaces opportunities for recreational services.