2026/05/01 by J. Kuttippurath, Vikas Patel · 1 voice
Environmental Science · Engineering · #Urban Heat Island Mitigation #Sustainable Building Design and Assessment #Land Use and Ecosystem Services
paper · doi:10.1016/j.cscee.2026.101387
openalex publication_date 2026/05/01 · openalex created_date 2026/05/06 · openalex updated_date 2026/07/23
The major challenges faced by large cities today are extreme heat and high levels of pollution, commonly referred to as Urban Heat Islands (UHI) and Urban Pollution Islands (UPI). These conditions make urban environments increasingly difficult places to live and thrive. Delhi, one of the largest cities in the world, experiences particularly high heat stress and severe pollution levels. In this context, we comprehensively assess the UHI and UPI effects and the sustainability of Delhi city, with new parameters and matrices related to heat and pollution. We introduce the concept of the Urban Heat and Pollution Island (UHPI) by analysing heat and air pollution indices together for Delhi, India. The Urban Pollution Island Index (UPII) developed in this study accounts for all major urban pollutants, unlike traditional indices that primarily focus on aerosols. We observe severe pollution in Delhi, particularly during the winter (December, January, and February) and post-monsoon (October and November) seasons. The UPII indicates that there are areas in Delhi where pollution is very high, even with planned urbanisation. Likewise, the UHI effect is also strong in Delhi and is stronger in spring (March, April, and May) and post-monsoon (1–3 °C). We find a synergy between UPI and UHI, and henceforth, we derive UHPI by taking into account both heat and pollution burdens in the city. Based on UHPI, we find that New Delhi (planned urban area) is exposed to a high level of pollution, even with a low heat burden. On the other hand, there are regions with high UHI and UPII (e.g. Faridabad in Delhi). These findings highlight the need for urban planning strategies that account for the present and future evolution of UHPI in cities. This study provides critical insights and introduces two important matrices that can support the planning and development of sustainable cities in India and worldwide.