Zhang Jun, Zhang Huina, Qi Ruoming
College of Landscape Architecture, Northeast Forestry University, Harbin, 150040, China.
Sci Rep. 2024 Jul 13;14(1):16176. doi: 10.1038/s41598-024-67277-2.
Rapid urbanization has led to increasingly prominent urban heat island phenomena and social inequality. It is urgent to quantify the threshold area of urban parks from multiple perspectives to maximize the cooling effect and improve the equity of park cooling services. Using 33 urban parks in Harbin City as research objects, four indices, i.e., park cooling intensity (PCI), park cooling distance (PCD), park cooling area (PCA), and park cooling efficiency (PCE), were used to explore the park cooling effect and the threshold value of efficiency (TVoE) of the size. The OD (origin-destination) matrix model was constructed to assess the spatial accessibility from the community to the cooling range. The Gini coefficient was used to assess the equity of cooling range accessibility. The relative contribution of each influencing factor to the cooling indicator was quantified through regression modeling. The results showed that the average PCI was 3.27 ℃, the average PCD was 277 m, the average PCA was 115.35 ha, and the average PCE was 5.74. Gray space area was the dominant factor for PCI, PCD, and PCA (relative contributions of 100%, 31%, and 19%, respectively). Park area was the dominant factor for PCE (relative contribution of 28%). The TVoE of park sizes based on PCA and PCE were calculated as 82.37 ha and 2.56 ha, respectively. 39.2% and 94.01% of communities can reach cooling ranges within 15 min in walk mode and transit mode, respectively. Approximately 18% of neighborhood residents are experiencing severe inequities in cooling range accessibility. This study can guide park design that maximizes cooling effects, as well as inform city planners on more equitable allocation of urban park resources.
快速城市化导致城市热岛现象和社会不平等日益突出。从多个角度量化城市公园的阈值面积，以最大化降温效果并提高公园降温服务的公平性迫在眉睫。以哈尔滨市的33个城市公园为研究对象，使用公园降温强度（PCI）、公园降温距离（PCD）、公园降温面积（PCA）和公园降温效率（PCE）这四个指标来探究公园降温效果和规模效率阈值（TVoE）。构建OD（起点 - 终点）矩阵模型来评估从社区到降温范围的空间可达性。使用基尼系数评估降温范围可达性的公平性。通过回归建模量化每个影响因素对降温指标的相对贡献。结果表明，平均PCI为3.27℃，平均PCD为277米，平均PCA为115.35公顷，平均PCE为5.74。灰色空间面积是PCI、PCD和PCA的主导因素（相对贡献分别为100%、31%和19%）。公园面积是PCE的主导因素（相对贡献为28%）。基于PCA和PCE计算的公园规模TVoE分别为82.37公顷和2.56公顷。在步行模式和公交模式下，分别有39.2%和94.01%的社区能够在15分钟内到达降温范围。约18%的社区居民在降温范围可达性方面存在严重不平等。本研究可为最大化降温效果的公园设计提供指导，并为城市规划者更公平地分配城市公园资源提供参考。
