Hydrodynamics of the Vadose Zone of a Layered Soil Column

Abstract

Getting into the heart of the water movement into the vadose zone is essential due to the direct impact on the aquifer recharge, the flood hazards, the irrigation planning and the water resources management in general. Since soil profiles in nature appear in layers, the present study accomplishes a deep investigation of the water’s motion through soil layers with different hydraulic properties. A series of experiments were conducted in the laboratory where infiltration, tension, soil moisture and hydraulic conductivity data were collected and analyzed. In particular, a transparent column was filled with two soils (loamy sand over sand), and TDR probes, along with ceramic capsules connected to pressure transducers, were set to the column. Using the experimental data and the unsaturated zone modeling, hydraulic parameters were obtained, along with water motion simulation and prediction. An investigation into the drainage, imbibition, infiltration, soil water characteristic curves and, in general, the hydrodynamics of the vadose zone of the soil layers has been achieved. The results of the current study suggest a method to estimate the crucial hydraulic parameters that are involved in the soil-water interaction and have an impact on infiltration, runoff, aquifer horizon recharge, water management and water saving.

Keywords

• hydraulic parameters
• hydraulic diffusivity
• specific water capacity
• sorptivity
• hydraulic conductivity
• retention curve