Soil drying and heat–moisture dynamics under simulated solar radiation using infrared energy

Abstract

The soil’s water and energy balance play a fundamental role in regulating the hydrological cycle and near-surface climatic conditions. Previous studies have demonstrated that coupled heat and moisture transport processes strongly affect soil evaporation and temperature dynamics. Building on this foundation, our study investigated the drying behaviour of soil columns exposed to infrared radiation simulating solar energy, with particular focus on heat and mass transfer at the soil-air interface. Laboratory experiments were performed on soil samples of different initial moisture conditions, including natural, water-saturated, and frozen states. Each experiment involved 12 hours of infrared exposure followed by 12 hours without irradiation, forming a 48-hour day–night cycle. Temperature and moisture content were measured at three depths, while surface temperature patterns and airflow dynamics were monitored with an infrared camera. Results showed pronounced temperature fluctuations and moisture loss in the upper soil layers. Infrared imagery clearly revealed convective airflows forming above the soil columns during heating. The experimental setup proved effective for analysing coupled heat and moisture transport. These findings enhance understanding of soil evaporation mechanisms and contribute to the development of sustainable soil–water management strategies.