Spatio-temporal dynamics of urban heat island in a coastal tropical city: A case study of Pangkal Pinang, Indonesia

Abstract Urban Heat Island (UHI) is a growing environmental issue in rapidly developing cities, including Pangkal Pinang, Indonesia. This study aims to map and analyze the spatial and temporal patterns of UHI over a 15-year period (2009–2024) using satellite-based thermal data. Landsat imagery was utilized, with Landsat 4 data applied for 2009 (Bands 3, 4, and 6) and Landsat 8 data for 2014 and 2024 (Bands 4, 5, and 10). Data collecting was conducted in Google Earth Engine while processed in arcmap 10.8, and surface temperature was derived using radiometric correction, brightness temperature calculation, NDVI-based emissivity estimation, and vegetation proportion modeling. The results show a significant increase in UHI intensity over time. In 2009, surface temperatures ranged from 15.64°C to 24.97°C, with cold spots widely distributed across forested and riparian zones. By 2014, surface temperatures ranged from 11.39°C to 28.95°C, though cold spots became more localized, primarily found in Gerunggang’s urban forest. In 2024, UHI intensified further, with temperatures reaching 32.17°C. The results of Spatio-temporal analysis (2009–2024) shows a 7.2°C temperature rise in Pangkal Pinang’s hottest areas, with heat zones shifting toward the urban core reflecting intensified UHI driven by urban growth, land cover change, and declining green infrastructure, and highlighting the city’s increasing climate vulnerability.