Urban heat dynamics in the tropical global south: remote sensing, modeling advances, and mitigation pathways from Southeast Asia (2019–2025)

Abstract

Rapid urban expansion across the tropical Global South has intensified urban heat island (UHI) effects, increasing climate risks and human vulnerability. This review synthesizes findings from more than 120 peer-reviewed studies (2019–2025) that apply remote sensing, spatial modeling, field observations, and policy analysis to examine UHI drivers and mitigation strategies. Evidence from rapidly growing Indonesian cities—such as Jakarta, Makassar, Denpasar, and IKN/Nusantara, alongside other Southeast Asian and global cities shows that land surface temperature (LST) rises with built-up expansion and bare soil (positively associated with NDBI), and declines with vegetation and water presence (negatively associated with NDVI and NDWI). Recent advances include cloud-gap thermal reconstruction, machine-learning projections (CA–ANN, XGBoost), and WRF–MODIS frameworks that address scale mismatches in LST estimation. Studies also identify coastal and industrial heat islands and document COVID-19-related shifts in heat exposure from commercial to residential areas. Nature-based solutions—urban forests, riparian corridors, and green roofs—demonstrate measurable cooling, complemented by high-albedo materials and improved urban form. However, governance limitations and socio-spatial inequality constrain implementation. The review outlines key metrics, uncertainties, and research priorities, including diurnal heat dynamics, industrial microclimates, mesoscale circulation, and equitable green infrastructure targets for tropical cities.