Mathivanan Mathan, Duraisekaran Elanchezhiyan
Centre for Climate Change and Disaster Management, Anna University, Chennai, Tamil Nadu, India.
Indian Institute of Technology, Madras, Chennai, Tamil Nadu, India.
Environ Monit Assess. 2024 Dec 21;197(1):91. doi: 10.1007/s10661-024-13472-7.
Rapid urbanization has altered land use and land cover to accommodate the growing population. This shift towards urbanization has resulted in the UHI effect, where the inner urban core is notably warmer than its surroundings. Existing research on UHI has primarily focused on major cities at the regional scale, leaving a gap in addressing the effect of extreme UHI zones within a city. This study bridges the gap by developing a methodology to quantify the impact of LULC change on the localized UHI zones within the urban areas, which will assist policymakers in mitigating urban heat. LULC change matrix analysis and LST retrieval were done from the Landsat 5 and 8 images acquired between 1988 and 2023. Representative study sites that intersected with the LULC conversion from water bodies and vegetation to other LULC and which showed maximum UHI were selected. Mean LST was calculated for the proximity of 1000 m around the selected areas. The developed methodology was applied to the Chennai Metropolitan Area in Tamil Nadu, India. The conversion of Pallikaranai marshland to the Perungudi dumping ground (PDG), and the green cover to the Kodungaiyur dumping ground (KDG) has led to an average increase in UHI intensity of 0.21 °C/year and 0.15 °C/year, respectively. The UHI effect is felt at the distance of 450 m from PDG and 550 m from KDG, which have shown that the life within the proximity are expected to experience the UHI effect. Therefore, it is imperative to alleviate the rising UHI around the selected areas. This developed methodology can be applied globally to select the targeted UHI zones for sustainable urban planning to mitigate urban heat.
快速城市化改变了土地利用和土地覆盖，以容纳不断增长的人口。这种向城市化的转变导致了城市热岛效应，即城市核心区域明显比周围环境温暖。现有的关于城市热岛效应的研究主要集中在区域尺度上的大城市，在解决城市内部极端城市热岛区域的影响方面存在空白。本研究通过开发一种方法来量化土地利用和土地覆盖变化对城市局部城市热岛区域的影响，填补了这一空白，这将有助于政策制定者缓解城市热岛效应。土地利用和土地覆盖变化矩阵分析以及地表温度反演是根据1988年至2023年期间获取的陆地卫星5号和8号图像进行的。选择了与从水体和植被向其他土地利用和土地覆盖类型转变且显示出最大城市热岛效应的代表性研究地点。计算了所选区域周围1000米范围内的平均地表温度。所开发的方法应用于印度泰米尔纳德邦的金奈大都市区。帕利卡兰奈沼泽地转变为佩伦古迪垃圾场以及绿地转变为科东加伊尤尔垃圾场分别导致城市热岛强度平均每年增加0.21℃和0.15℃。在距离佩伦古迪垃圾场450米和距离科东加伊尤尔垃圾场550米的范围内能感受到城市热岛效应，这表明附近区域的居民预计会受到城市热岛效应的影响。因此，必须缓解所选区域周围不断上升的城市热岛效应。这种开发的方法可以在全球范围内应用，以选择有针对性的城市热岛区域进行可持续城市规划，以减轻城市热岛效应。
