Assessing & mitigating urban heat island in Colombo to achieve SDG 11 and SDG 13

Abstract

Rapid urbanization in Colombo, Sri Lanka, has intensified the Urban Heat Island (UHI) effect, raising local temperatures, increasing energy use, and stressing urban infrastructure. This study assesses spatial and temporal UHI dynamics in Colombo from 2001 to 2024 using multi-temporal satellite data, remote sensing, and GIS-based analysis. Land Surface Temperature (LST), land cover, and ecological indices (NDVI, NDBI, NBUI, UTFVI) were analyzed to identify trends and hotspots. Results show a rise in built-up areas, a decline in vegetation, and increased LST, with 39% of the city experiencing extreme heat stress, especially in dense urban cores. The study recommends increasing urban green cover, using high-albedo materials, and implementing climate-sensitive planning to align with SDGs 11 and 13. These findings provide a replicable framework for UHI mitigation and support sustainable, climate-resilient urban development in Colombo.