Spatio-Temporal Dynamics of Land Surface Temperature in the Theri Soil Landscape and Its Thermal Association with Surrounding Land Uses

Abstract Land surface temperature (LST) provides an important indicator of surface thermal behaviour and reveals differences in energy exchange across heterogeneous landscapes. This study investigated the spatio-temporal dynamics of LST over the Theri soil landscape of southern Tamil Nadu, India, and its thermal association with surrounding built-up, vegetation, agricultural and barren land uses across multiple spatial scales. Landsat 8 imagery from 2015–2024 was processed in Google Earth Engine to derive LST and assess thermal relationships within 0–1, 1–2 and 2–5 km zones from the Theri soil boundary. Temporal analysis, correlation matrices and pairwise scatter plots were used to evaluate thermal synchrony and spatial dependence, complemented by ground observations from representative landscape conditions. Theri soil exhibited substantial seasonal and interannual variability and generally higher LST than vegetated and agricultural surfaces. The strongest association occurred between Theri soil and built-up land at 1 km (r = 0.92), decreasing to 0.85 and 0.82 at 2 and 5 km, respectively. Vegetation and agriculture also remained strongly associated with Theri soil, whereas barren land exhibited a strong but non-monotonic relationship across spatial scales. Field observations revealed pronounced thermal contrasts, with exposed red sand reaching 57.3°C compared with substantially lower temperatures under vegetated conditions. The findings demonstrate that Theri soil forms a distinct yet thermally interconnected landscape unit and highlight the importance of spatial context, vegetation cover and surrounding land-use characteristics in understanding its thermal behaviour.