Numerical Simulation of Water Transfer in Unsaturated Soils: Evaluating the Effects of Temperature and Root Activity in Water Distribution

Abstract

In a complex medium, particularly soil, understanding water movement is essential for optimizing water management in agricultural and natural ecosystems. This study presents a theoretical and numerical analysis of the influence of temperature variations and root activity on water retention and redistribution in soils with variable saturation. A finite element model was developed to simulate water flow, integrating temperature-dependent hydraulic properties and dynamic root water uptake. Simulations revealed that a 10°C increase in soil temperature can reduce water content by up to 15% in the top 20 cm of soil due to increased evapotranspiration and reduced matric potential. Root water uptake responds dynamically to thermal conditions, with uptake rates increasing by around 20% under moderate warming, particularly in the upper soil layers. These results demonstrate the strong coupling between thermal gradients, root function, and soil moisture distribution. They improve our ability to predict soil-plant-atmosphere interactions under changing climatic conditions and provide valuable information for optimizing irrigation strategies and ensuring sustainable use of water.