深圳市城市居住单元绿化水平与空间差异研究

Research on the Greening Rate and Spatial Differences of Urban Residential Neighborhoods in Shenzhen

居住区绿地是城市居民使用最多的城市绿地类型之一。鉴于既有绿化指标无法准确衡量城市居住区绿化水平的空间差异,本文提出居住单元绿化覆盖率、绿视率、500m范围内的公园绿地率三项居住单元绿化指标,旨在探讨城市绿地服务的公平性问题。研究以2017年的深圳市建成区居住单元为例,利用土地覆被图、街景图片等建立了包含14196个居住单元的绿化数据库,并测算了每个居住单元的三项绿化指标值,衡量了居住单元绿化水平及其空间差异的影响因素。研究表明:1)三项指标均可独立反映居住单元内部或周边绿化水平;2)居住单元的绿化覆盖率、500m范围内的公园绿地率均较低,绿视率较高;3)不同居住单元内部、500m范围内的公园绿地,以及不同房屋产权类型的居住单元的绿化水平存在较大空间差异,绿地服务的公平性不足;4)居住单元绿化水平受开发强度、房屋产权类型、海拔和区位等地理空间因素影响。研究建议城市绿地布局应考虑与居住单元的空间关系,关注弱势群体的绿地服务质量,并重视居住区绿化指标的多维化,尤其可将500m范围内的公园绿地率作为现有居住区绿化指标体系的补充指标。

Residential green spaces are one of the most frequently used urban green space types.Aiming at filling a gap in the existing greening indicators with considerations on the spatial differences of residential green spaces,as well as to inform the improvement of urban green space service,three greening indicators,i.e.residential unit’s green coverage rate,green view index,and park ratio within a 500 m service radius,are proposed in this paper.This study selects 14,196 residential units in built area of Shenzhen City in 2017 to measure the greening rate and the geographic spatial factors of the units upon multi-sourced geographic databases such as land cover maps and street view images.The research reveals that:1)the three indicators can all independently measure the greening rate within or around residential units;2)the studied residential units are low in residential unit’s green coverage rate and park ratio within a 500 m service radius,but high in green view index;3)there are significant disparities of the greening rate and the surrounding parks in 500 m service radius among the studied units,and among different housing property rights,showing a disequilibrium in green space service;and 4)the greening rate of residential units is mainly impacted by factors such as development intensity,types of housing property right,altitude,and location.In conclusion,it is suggested that urban green space layout should prioritize improving the spatial distribution and layout of residential green spaces,especially for the socially vulnerable population.Finally,the study points out that the park ratio within a 500 m service radius can be adopted as a supplement to existing greening indicators for residential areas.