2026 INTERNATIONAL JOURNAL OF LOW-CARBON TECHNOLOGIES 2026 21(卷), null(期), (null页)
In this research, the thermal behavior of shallow subsoil in Gharda & iuml;a, Algeria, is experimentally investigated, with a focus on surface geothermal energy systems. From March 2020 to November 2023, air, surface, and subsurface temperatures (0-5 m) and other parameters such as solar radiation, humidity, wind speed, precipitation, and air pressure have been monitored. It was found that soil thermal diffusivity is a decreasing function of depth, with values of 7.31 & times; 10-7 m2/s and 5.64 & times; 10-7 m2/s in the 0-1 and 4-5 m depth ranges, respectively. At depths >= 4 m, temperatures are stable and equal to 24 degrees C, showing a strong thermal damping effect and a notable phase lag. A predictive model of subsurface temperatures with an RMSE of 0.255 degrees C and R2 of 0.995 is in good agreement with measured temperatures. Future research directions include a deeper subsoil investigation and the potential of integrating geothermal energy with other renewable energy resources in arid regions.