Assessment of critical thermal characteristics and land surface dynamics of an Indian metropolitan city

Abstract

ABSTRACT Monitoring urban heat islands (UHIs) is crucial as it has become a major health hazard. This paper focuses on an empirical study analyzing causes and spatiotemporal attributes in a tropical metropolis to enrich the urban climate database. A comparative assessment of temperature patterns from Landsat and Terra satellite sensors was performed for day–night scenarios for summer and winter. Results showed that from 2003 to 2014, there was a sharp rise of about 4 °C in average daytime temperature in summer. The temporal UHI increased by 28.52% for summer and 8.37% for winter in the last two decades. The thermal hotspot development was linked to land cover dynamics using surface indices, land use land cover, and local climate zone patterns. The dense green cover was reduced by 652.69 km2, reflecting the major cause behind hotspot development. The presence of water content was reduced, as depicted by a drop in maximum NDWI values from 0.425 to 0.152. The study identified compact mid-rise building arrangements within the built area as critical for hotspot creation. Green roofing with low plants should be prioritized at such locations since it can reduce the average temperature by 2.6 °C. This thorough analysis of climate change will aid in sustainable planning for similar city regions.