长春市绿地空间配置特征与降温效率的动态响应

Dynamic Response of Green Space Configuration and Cooling Efficiency in Changchun City

为应对快速城镇化过程中愈发严重的热岛效应,如何针对面积有限的绿地进行空间配置特征优化,使其降温效率最大化,亟待深入探究。以高分2号遥感影像为数据源提取长春市城市绿色空间分布格局,引入景观参数研究其分布情况;利用劈窗算法获取地表温度,研究城市绿地的降温效率及其影响因素,结果表明:1)0.5≤S<1hm^(2)的绿地,增加植被覆盖率能够显著提升其降温效率;1≤S<5hm^(2)的绿地,增加绿地面积或植被覆盖率能够提升其降温效率;5≤S<10hm^(2)的绿地,紧凑、点状的绿地的降温效率优于线状绿地;S≥10hm^(2)的绿地,其降温效果不再随面积增大而提升。2)城市绿地面积越大,降温范围越大,但是二者的相关性不明显,通常绿地的降温范围为150~400m。研究结果可以指导城市绿地布局、形状、大小等配置特征的优化,使其降温效率最大化,以达到降低温度、减缓城市热岛效应的目的。

How to optimize the spatial configuration characteristics of urban green space to maximize its cooling efficiency needs to be further explored.In this study,GF-2 remote sensing image was used as the data source to extract urban green space in Changchun and landscape parameters were introduced to study its distribution.Based on the surface temperature obtained by the split-window algorithm,the cooling efficiency of urban green space and its influencing factors were studied.The results show that 1)For 0.5≤S<1 hectares of green space,increasing vegetation coverage can significantly enhance its cooling efficiency.For 1≤S<5hectares of green space,increasing green land area or increasing vegetation coverage is more effective.For 5≤S<10 hectares of green space,the cooling efficiency of compact and point-like green space is better than that of linear green space.For S≥10 hectares of green space,the increase of green space cooling efficiency is not obvious.2)The larger the area of urban green space is,the larger the cooling range is,but the correlation between the two is not obvious.Usually,the cooling range of green space is 150-400m.The research results can guide the adjustment of the layout,shape,size,and other configuration characteristics of urban green space.To reduce the temperature and slow down the urban heat island effect,the cooling efficiency can be maximized.