Department of Geographic Information Science, Central South University of Forestry and Technology, 498 Shaoshan Nan Street, Changsha 410004, China.
Department of Ecological Landscape Architecture Design, Kangwon National University, Gangwon-Dae-Hak-Gil 1, Chuncheon 24341, Republic of Korea.
Int J Environ Res Public Health. 2023 Feb 1;20(3):2613. doi: 10.3390/ijerph20032613.
The cooling effects of blue-green spaces on the urban heat island effect are complex and different. The purpose of this study is to simulate how the cooling effect of blue-green space changes with its size and shape. The cooling effects of 53 green patches and 28 water bodies in Changsha were extracted based on Landsat images. A surface fitting model was used to quantitatively reveal the relationship between the cooling effect of blue-green space and its size and shape. The results show that the cooling effects of blue-green spaces were enhanced with the increasing size, and then would become stable after a certain range (threshold). Certain thresholds were identified between the blue and green space areas (2.98 ha and 3.15 ha, respectively) and the cooling distance, and between the blue and green space areas (4.84 ha and 4.92 ha, respectively) and the cooling magnitude. In addition, the green space with an area of 9.08 ha and landscape shape index (LSI) of 2.97 could achieve a better cooling distance (413.46 m); and the blue space with an area of 29.4 ha and LSI of 1.75 could achieve a better cooling magnitude (5.17 °C). These findings provide useful guidelines for urban planning and improving urban livability in other regions with terrain and climate conditions similar to Changsha.
蓝绿空间对城市热岛效应的冷却效果是复杂且不同的。本研究旨在模拟蓝绿空间的冷却效果随其大小和形状的变化。基于 Landsat 图像，提取了长沙 53 个绿色斑块和 28 个水体的冷却效应。采用曲面拟合模型定量揭示了蓝绿空间冷却效果与其大小和形状之间的关系。结果表明，蓝绿空间的冷却效果随其面积的增加而增强，在一定范围（阈值）后趋于稳定。在蓝绿空间面积与冷却距离之间（分别为 2.98 公顷和 3.15 公顷）以及蓝绿空间面积与冷却幅度之间（分别为 4.84 公顷和 4.92 公顷）确定了一定的阈值。此外，面积为 9.08 公顷、景观形状指数（LSI）为 2.97 的绿地可以实现更好的冷却距离（413.46 m）；面积为 29.4 公顷、LSI 为 1.75 的蓝地可以实现更好的冷却幅度（5.17°C）。这些发现为城市规划和提高其他类似长沙地形和气候条件地区的城市宜居性提供了有用的指导。
