An Urban Heat Island Study of the Colombo Metropolitan Area, Sri Lanka, Based on Landsat Data (1997-2017)
An Urban Heat Island Study of the Colombo Metropolitan Area, Sri Lanka, Based on Landsat Data (1997-2017)
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DOI：
10.3390/ijgi6070189
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发表时间：
2017-07-01
影响因子：
3.4
通讯作者：
Murayama, Yuji
中科院分区：
文献类型：
--
作者：
Ranagalage, Manjula;Estoque, Ronald C.;Murayama, Yuji
与无计划的城市快速增长相关的主要影响之一是城市植被的减少，这些植被通常被建筑物、停车场、道路和人行道等不透水的表面所取代。因此，随着不透水地表的比例继续增加，以植被覆盖为代价，地表城市热岛（SUHI）形成并变得更加强烈。斯里兰卡科伦坡大都市区（CMA）是南亚快速城市化的大都市区之一。在此研究中，我们利用Landsat数据研究了SUHI现象背景下CMA的地表温度（LST）的时空变化。在1997年、2007年和2017年三个时间点，研究了地表温度与归一化植被指数（NDVI）和归一化建筑指数（NDBI）的关系。此外，我们还基于LST和NDVI确定了环境关键区域。我们发现，在所有三个时间点上，LST与NDVI（负）和NDBI（正）显著相关（p < 0.001）。大多数环境关键区域位于中央商务区（CBD）、港口附近、沿海地带和主要交通网络沿线。我们建议在未来的城市规划和城市景观发展中考虑那些已确定的环境关键地区。绿色空间有助于提高CMA的环境可持续性。
One of the major impacts associated with unplanned rapid urban growth is the decrease of urban vegetation, which is often replaced with impervious surfaces such as buildings, parking lots, roads, and pavements. Consequently, as the percentage of impervious surfaces continues to increase at the expense of vegetation cover, surface urban heat island (SUHI) forms and becomes more intense. The Colombo Metropolitan Area (CMA), Sri Lanka, is one of the rapidly urbanizing metropolitan regions in South Asia. In this study, we examined the spatiotemporal variations of land surface temperature (LST) in the CMA in the context of the SUHI phenomenon using Landsat data. More specifically, we examined the relationship of LST with the normalized difference vegetation index (NDVI) and the normalized difference built-up index (NDBI) at three time points (1997, 2007 and 2017). In addition, we also identified environmentally critical areas based on LST and NDVI. We found significant correlations of LST with NDVI (negative) and NDBI (positive) (p < 0.001) across all three time points. Most of the environmentally critical areas are located in the central business district (CBD), near the harbor, across the coastal belt, and along the main transportation network. We recommend that those identified environmentally critical areas be considered in the future urban planning and landscape development of the city. Green spaces can help improve the environmental sustainability of the CMA.