Spatial Changes of Urban Heat Island Formation in the Colombo District, Sri Lanka: Implications for Sustainability Planning
Spatial Changes of Urban Heat Island Formation in the Colombo District, Sri Lanka: Implications for Sustainability Planning
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DOI：
10.3390/su10051367
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发表时间：
2018-04
期刊：
影响因子：
3.9
通讯作者：
M. Ranagalage;R. Estoque;Xinmin Zhang;Y. Murayama
中科院分区：
文献类型：
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作者：
M. Ranagalage;R. Estoque;Xinmin Zhang;Y. Murayama
城市地表热岛（SUHI）的形成会对城市地区的生活质量造成重大不利影响。监测城市热岛形成的空间模式和轨迹可能有助于城市规划者制定适当的缓解和适应措施。本研究探讨了SUHI形成在科隆博区（斯里兰卡）的空间格局，基于陆地表面温度（LST），归一化差异植被指数（NDVI），归一化差异建成指数（NDBI），和人口密度（PD）使用基于地理空间的热点和冷点分析工具。在这里，“热点”是指高变量值在空间上具有显着聚集的区域，而“冷点”是指低变量值在空间上具有显着聚集的区域。结果表明，1997年至2017年，科隆博区557个分区中有32.7%仍然是热点。这些热点的特点是由四个变量（LST，NDVI（倒置），NDBI和PD）产生的高综合指数值的显着聚类。这项研究还确定了新出现的热点，占49个部门（8.8%）。在该地区的西侧发现了两个时间点之间的大簇热点，而在该地区的东侧发现了冷点。被确定为热点的地区是该地区城市化程度较高的地区。新出现的热点位于因城市化而发生地貌变化的地区。这些地区位于持续热点（该区西部）和持续冷点（该区东部）之间。总体而言，新兴热点的空间格局遵循该地区城市化的格局，即从西向东扩展。总体而言，这项研究的结果可以作为参考的背景下，可持续景观和城市规划的科隆博区。
The formation of surface urban heat islands (SUHIs) can cause significant adverse impacts on the quality of living in urban areas. Monitoring the spatial patterns and trajectories of UHI formations could be helpful to urban planners in crafting appropriate mitigation and adaptation measures. This study examined the spatial pattern of SUHI formation in the Colombo District (Sri Lanka), based on land surface temperature (LST), a normalized difference vegetation index (NDVI), a normalized difference built-up index (NDBI), and population density (PD) using a geospatial-based hot and cold spot analysis tool. Here, ‘hot spots’ refers to areas with significant spatial clustering of high variable values, while ‘cold spots’ refers to areas with significant spatial clustering of low variable values. The results indicated that between 1997 and 2017, 32.7% of the 557 divisions in the Colombo District persisted as hot spots. These hot spots were characterized by a significant clustering of high composite index values resulting from the four variables (LST, NDVI (inverted), NDBI, and PD). This study also identified newly emerging hot spots, which accounted for 49 divisions (8.8%). Large clusters of hot spots between both time points were found on the western side of the district, while cold spots were found on the eastern side of the district. The areas identified as hot spots are the more urbanized parts of the district. The emerging hot spots were in areas that had undergone landscape changes due to urbanization. Such areas are found between the persistent hot spots (western parts of the district) and persistent cold spots (eastern parts of the district). Generally, the spatial pattern of the emerging hot spots followed the pattern of urbanization in the district, which had been expanding from west to east. Overall, the findings of this study could be used as a reference in the context of sustainable landscape and urban planning for the Colombo District.