高密度建成区城市生态空间的热环境缓释效应--以广州市中心城区为例

Thermal Environment Effect of Urban Ecological Space in High Density Urban Built-up Areas:A Case Study of the Central Urban District of Guangzhou

随着全球城市化进程的推进,城市热岛效应已成为当下严重的环境问题之一,严重制约人类健康与城市的可持续发展。城市生态空间对城市热岛效应的缓解具有重大意义,而目前,从局地效应角度研究城市生态空间对热环境影响还比较缺乏,影响城市生态空间降温效应的因素还未明了。因此,本文基于多源遥感数据,对广州市中心区生态空间进行识别并反演地表温度,定量刻画城市核心区内部生态空间的降温强度,以探讨广州市生态空间斑块结构特征和空间布局对周边环境温度的影响。结果表明:⑴生态空间与地表温度的空间分布具有明显的高低值耦合分布趋势,生态空间越集中连片分布,越有利于促进局地热量扩散,以缓解城市的热岛效应;⑵生态空间对周边环境降温强度主要由其空间结构特征和空间位置共同决定,当生态空间的空间结构特性保持一定时,其所处的空间位置不同对缓解周围城市热环境的作用也有所差异。本研究揭示城市生态空间的结构特征及其周围环境对冷却效应强度的影响机制,为促进城市的可持续发展提供有益的建议。

In the global process of rapid urbanization, one of the world＇s most phenomenal environmental problems is the urban heat island （UHI） effect. This effect seriously hampers human health and the sustainable development of cities. Urban ecological space is one of sig- nificance factors to alleviate the UHI effect. Less attention, however, has been directed to the effects of urban ecological space patterns on their own thermal environment effect at patch level. Moreover, the factors that affect the cooling effect of urban ecological space are still unknown. Therefore, in this study, we focused on the effects of spatial patterns of urban ecological space on their own thermal environment effect and the cooling intensity of the ecological space in the urban core area was quantitatively described. Results indicate that： （1） The spatial distribution of ecological space and land surface temperature has an obvious trend of high and low value coupling distribution, the more concentrated distribution of ecological space, the more conducive to the promotion of local heat diffusion. （2）The cooling intensity of ecological environment to thesurrounding environment is mainly determined by its spatial patterns and spatial location. Fur- ther, when the spatial structure characteristics of the ecological space are maintained, the spatial location of the ecological environment has different effects on the mitigation of the urban thermal environment. The results of this study suggest that the spatial patterns of urban ecological space and the influence mechanism of the surrounding environment on urban ecological space cooling effect intensity, which can provide some useful suggestions for the sustainable development of the city.