Cartographie et analyse de l’ilot de chaleur par la télédétection de la température de surface du sol dans la zone littorale ouest de Mostaganem.

Abstract

Land surface temperature (LST) is an important indicator for studying climate change, heat balance, the urban environment, and hydrological and agricultural processes. LST is a key variable to be retrieved from Landsat satellite thermal images (Jimenez-Munoz et al., 2014). In our present study, we mapped the soil LST of the study area using the single-channel (or split-window ‘SW’) method applied to the thermal band (band 10) of the Landsat-8 satellite. To do this, we processed six (06) satellite images acquired between March and August 2025 by the thermal sensor (TIRS) of the Landsat-8 satellite using ENVI version 5.3 and ArcGis version 10.8 software. The ENVI software tools were used to correct the images in terms of atmospheric and radiometric conditions. The image correction methods made the images usable and exploitable. Using these corrected images, we determined the LST in degrees Celsius based on the surface emissivity contained in the pixels of the thermal images. These remote sensing methods enabled us to produce six (6) monthly maps (March to August 2025) of thermal radiation or LST for the study area. The maps show that LST varies according to season, space and time. Between March and August 2025, estimated LST values (minimum and maximum) increased to 7.72°C and 14.02°C in six months, corresponding to 1.29°C and 2.33°C/month. Spatially, the maps show that more than 80% of the total area experienced temperatures above 30°C, with 83.66% in urban areas and 83.17% in rural areas. This shows that heat islands in urban areas are higher than in rural areas. The rest of the territory, namely 16.34% of the urban total and 16.83% of the rural total, is located below temperatures of 30°C, which shows that there are also cool islands in the study area. LSTs above 30°C occupied 73% of the urban total in the municipality of Mostaganem, 18% in Mazaghrane, 5% in Stidia and 4% in Ben Abdel Malek Ramdane. The LST maps made it possible to locate heat and cool islands in the area, which managers and decision-makers will need to be alerted to in order to closely monitor and supervise agriculture, forests and the urban environment against summer heat islands.