Australian Research Council Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, Australia.
School of Built Environment, University of New South Wales, Sydney, Australia.
Sci Rep. 2022 Sep 14;12(1):15433. doi: 10.1038/s41598-022-19431-x.
Cities with different background climates experience different thermal environments. Many studies have investigated land cover effects on surface urban heat in individual cities. However, a quantitative understanding of how background climates modify the thermal impact of urban land covers remains elusive. Here, we characterise land cover and their impacts on land surface temperature (LST) for 54 highly populated cities using Landsat-8 imagery. Results show that urban surface characteristics and their thermal response are distinctly different across various climate regimes, with the largest difference for cities in arid climates. Cold cities show the largest seasonal variability, with the least seasonality in tropical and arid cities. In tropical, temperate, and cold climates, normalised difference built-up index (NDBI) is the strongest contributor to LST variability during warm months followed by normalised difference vegetation index (NDVI), while normalised difference bareness index (NDBaI) is the most important factor in arid climates. These findings provide a climate-sensitive basis for future land cover planning oriented at mitigating local surface warming.
具有不同背景气候的城市经历着不同的热环境。许多研究已经调查了土地覆盖对单个城市表面城市热的影响。然而，对于背景气候如何改变城市土地覆盖物的热影响，定量的理解仍然难以捉摸。在这里，我们使用 Landsat-8 图像描述了 54 个人口稠密城市的土地覆盖及其对地表温度（LST）的影响。结果表明，城市表面特征及其热响应在不同的气候区系中明显不同，干旱气候下的城市差异最大。寒冷的城市表现出最大的季节性变化，而热带和干旱的城市则季节性最小。在热带、温带和寒冷气候下，在温暖的月份，归一化差异建筑指数（NDBI）是 LST 变化的最强贡献者，其次是归一化差异植被指数（NDVI），而在干旱气候下，归一化差异光秃指数（NDBaI）是最重要的因素。这些发现为未来以缓解局部地面变暖为目标的土地覆盖规划提供了一个气候敏感的基础。
