Experimental Determination of Hydraulic Conductivity at Unsaturated Soil Column

Abstract

Hydraulic Conductivity (K) is an important hydraulic parameter as it affects the environment by controlling infiltration, irrigation rate, and consequently the water movement through the ground. In order to determine Hydraulic Conductivity in a soil column during unsaturated flow, experiments were performed in the laboratory. A sandy (S) soil sample of known Hydraulic Conductivity at saturation (KS) was placed uniformly in a transparent column. Using a pump, water was applied at the surface of the soil column in certain supplies (Qi), while soil moisture (θ) was measured using TDR probes. At the same time, soil pore pressure (h) was measured using pressure transducers. The cumulative volume of the outgoing water (V) of the column was measured. Experimental data were fitted by Van Genuhten's Hydraulic Conductivity model. The results of the above experimental procedure constitute useful tools for the simulation of water movement in unsaturated soils and can be the outset for further research.