Identifying temperature ‘hotspots’ for increasing urban resilience to heat stress in Kolkata, West Bengal, India

Abstract. Climate change and rapid urbanization have led to increased temperatures in cities, particularly during summer. With projections indicating that over two-thirds of the global population will be urban by 2050, the disruption of biophysical processes and rising intra-urban temperatures pose serious health and environmental concerns. To monitor urban temperature distribution, researchers use ground-based meteorological stations for air temperature and satellite data for land surface temperature (LST). LST maps are especially valuable for identifying temperature “hotspots”—areas with significantly higher temperatures—which can guide targeted adaptation and mitigation strategies. This study focuses on identifying such hotspots in Kolkata district, West Bengal, using Landsat-8 satellite data. Key hotspots include Dhapa (a landfill site), Kidderpore, Chitpur, and Cossipore. Residents in slums near these hotspots face severe challenges during summer, including lack of clean drinking water and extreme heat. Women are disproportionately affected due to domestic responsibilities and social restrictions that prevent them from sleeping outdoors, unlike men.

The analysis reveals that northeastern and mid-western parts of Kolkata are warmer, while central and eastern areas are relatively cooler. This correlates with the presence of blue-green infrastructure, as indicated by NDVI (Normalized Difference Vegetation Index) calculations. To enhance urban resilience, the study recommends afforestation and development of green infrastructure in hotspot areas. Techniques like Miyawaki plantations can rapidly establish urban forests, contributing to climate adaptation and fulfilling Sustainable Development Goals (SDGs) 5 (gender equality) and 11 (sustainable cities and communities).