Thermal Dynamics of Peri-Urban Landscapes: A Paired Spatial Analysis of Brick Kilns and Bare Soil in León, Guanajuato

José Javier Gutiérrez Ramírez , Cesar Delgado Cardona, Angel Arturo Carranco, Carlos Josue González Silva, Mónica Aidee Ortiz Márquez, José Roberto Romero Soto, Erick Josué Pérez Zúñiga, Gabriela Infante Oliva

Urban expansion and industrial activities in peri-urban environments modify land cover and influence surface thermal patterns. This study examines the thermal behavior of artisanal brick kilns in León, Guanajuato, Mexico, using a paired spatial approach designed to distinguish the contribution of kiln activity from that of the surrounding landscape. Landsat 8 Collection 2 Level-2 imagery acquired during the dry seasons (March-May) of 2024-2026 was processed in Google Earth Engine. Eight active brick kiln polygons were paired with eight bare-soil control sites and evaluated within concentric buffers of 100, 500, and 1000 m. Eight spectral and thermal indices, including Land Surface Temperature (LST), NDVI, and NDMI, were calculated. Wilcoxon signed-rank and Mann-Whitney U tests indicate that bare-soil control sites consistently exhibited higher LST values than active brick kilns, with a mean difference of approximately $\Delta LST\approx-3.7^{\circ}C$. Spearman correlation showed a moderate inverse relationship between LST and NDMI $(\rho\approx-0.49)$, indicating that higher surface temperatures are associated with reduced vegetation moisture. The results indicate that, under the analyzed daytime Landsat observations, exposed bare soil exhibited higher surface temperatures than the active brick kiln polygons. This three-year assessment provides a reference for monitoring peri-urban thermal conditions and supports the use of paired multi-buffer analyses to evaluate the effects of land cover on surface temperature.