Thirty-five years of urban expansion and thermal transformation: Integrating LULC change climate variability and population growth

Abstract Rapid urban expansion can alter surface thermal conditions, yet these changes are often evaluated without accounting for climatic variability, demographic pressures, and uncertainty. This study investigated long-term land-use/land-cover (LULC) and thermal dynamics in Jhang District, Pakistan, for 1990, 2000, 2010, 2020, and 2025 using Landsat-based LULC classification, land surface temperature (LST), surface urban heat island (SUHI), Urban Thermal Field Variance Index (UTFVI), spectral indices, Getis–Ord Gi* hotspot analysis, Pearson correlation, and multiple linear regression (MLR). Landsat-derived LST was independently compared with MODIS, while ERA5-Land, CHIRPS, and GHS-POP were used to characterize climatic and demographic context. Urban land expanded from 62.67 km² (0.98%) to 341.36 km² (5.37%), with 219.53 km² of Vegetated Land converted to Urban land. Maximum LST increased from 49.09 °C to 55.01 °C, while 99% confidence hot spots expanded from 856.42 to 1,041.31 km². LST was negatively correlated with NDVI and NDMI and positively correlated with NDBI and NDBaI. MLR models explained 54.2–83.1% of spatial LST variability. MODIS comparison showed strong spatial correspondence (R 2 = 0.752–0.843) despite systematic absolute-temperature differences. Air temperature increased significantly by 0.199 °C decade⁻¹, while population rose from 1.58 to 3.44 million. The findings demonstrate that Jhang’s thermal evolution reflects interacting land-cover, climatic, and demographic pressures rather than urban growth alone.