A multivariate geostatistical framework to assess the spatio-temporal dynamics of coupled urban–thermal–ecological interactions in the western Himalaya foothills

• 1993–2024 Landsat links LULC shifts to rising LST and UHI in Doon Valley. • Mean LST +9.17°C; urban +133%, agriculture −66%, water −95% since 1993. • Built-up/bare soils hottest (34–40°C); vegetation/water coolest (26–32°C). • LST rises with NDBI/BSI/UTFVI, falls with SAVI; urban hotspots surge after 2015. Thermal stress and ecosystem degradation are being accelerated by rapid urbanization in ecologically sensitive mountain valleys. Nevertheless, there are still few integrated multi-decadal evaluations that connect coupled thermal-ecological processes with LULC transitions in Himalayan ecosystems such as Doon Valley. This paper fills this gap with a new multi-index model that examines 31 years of Landsat data (1993-2024) to measure urbanization driven LULC changes, LST warming, and UHI impacts. Based on integrated spectral indices (NDVI, SAVI, NDBI, BSI), thermal measures (LST, UTFVI, and EEI), we find: (i) urban growth of 133% mainly due to agricultural conversion; (ii) 66% agricultural loss; (iii) average LST growth of 9.17°C accelerating Constructed/bare surfaces are 34-40°C whereas vegetated are colder (26-32°C). The rigorous multi-sensor validation (OA 93-97% and Kappa 0.91-0.96) and multi-index integration give the world the new insights of spatial heterogeneity, showing the loss of impervious surfaces and blue-green infrastructure as the thermal drivers, as equal to single-factors analysis. The spatial hotspot maps and ecological vulnerability indices in this investigation give practical advice to municipal planners at the ward scale, including the need to protect riparian corridors/wetlands, increase city vegetation in the form of parks, street trees, and green roofs, rehabilitate water bodies and natural drainage, encourage compact development with mixed uses, and climate-adaptive land-use strategies with a primary focus on agricultural protection. It can be also supported by SDG 11 (sustainable cities), SDG 13 (climate action), and SDG 15 (life on land) because the replicable framework can provide evidence-based approaches to sustainable development under the conditions of thermal-hydrological-ecological challenges of rapidly urbanizing mountainous areas.