Urban Heat–Health Risk assessment over Ahmedabad city, India: A Hyperlocal approach using WRF Model and Satellite Data

Heat–health risk assessment forms a cornerstone of climate-resilient urban planning and is essential for advancing the United Nations Sustainable Development Goals (SDGs 3, 11, 13, and 15). In this study, a hyperlocal, high-resolution analysis was carried out for Ahmedabad—one of India’s fastest-growing metropolitan regions with a population exceeding 8.2 million. Using the Weather Research and Forecasting (WRF) model, key meteorological variables including 2-m air temperature and relative humidity were simulated at an hourly timestep and 1 km × 1 km spatial resolution for an extreme-heat episode from 18 to 25 May 2024.
The Heat Index was computed for each grid cell and subsequently integrated with population density and vegetation scarcity (derived from satellite-based greenness indicators) to develop a Heat-Health Risk Index (HHRI). The HHRI was classified into five categories—very low (0–0.1), low (0.1–0.2), moderate (0.2–0.3), high (0.3–0.4), and very high (>0.4). A unique component of this study is the computation of occurrence frequency of each HHRI class at every grid cell across all heat-wave hours, generating the first spatially continuous temporal–risk map for the city at this granularity.
Results reveal that approximately 6% of Ahmedabad experienced very-high heat-health risk during 10–40% of all heat-wave hours, while about 17% of the city encountered high risk for 30–45% of the period. At the ward level, Khokhra, Khadia, Amraiwadi, and Bhaipura-Hatkeshwar emerged as persistent heat-stress hotspots, spending nearly 15% of the time in the very-high-risk category. Fifteen additional wards faced high or very-high risk for at least one-third of the event. In contrast, peri-urban wards such as Gota, Chandlodia, Chandkheda, Thaltej, and Bodakdev exhibited very-low risk for more than 90% of the period, attributed to lower population density and higher vegetation cover.
This hyperlocal heat-health risk framework provides actionable insights for strengthening Ahmedabad's Heat Action Plan. By revealing fine-scale spatial and temporal variations in vulnerability, the study offers a robust evidence base for targeted interventions, resource prioritisation, and long-term climate and public-health planning. The approach can be replicated for other Indian and global cities seeking data-driven strategies to build resilience against intensifying heatwaves.

keywords:Heat Health Risk Assessment, Urban Heat, Ahmedabad, WRF Model, Heat Action Plan, SDGs