LABORATORY EXPERIMENTS ON WATER MOVEMENT IN A LAYERED SOIL SAMPLE USING TDR METHOD

摘要

There is a continuing need to study soil-water movement concepts because of its importance for agriculture considering its influence on plant growth and soil quality. The object of this paper is to study water movement into a layered soil sample packed in a transparent vertical column. The sample was subjected to a wetting from the bottom of the column and a drainage process was following. The column was instrumented with tensiometers (pressure transducers in porous plate housings) to measure pressure and matric water potential and with Time Domain Reflectometry (TDR) probes to measure the volumetric moisture content. The pressure transducers were arranged in four different locations into the column. At the same locations TDR probes of 5 cm in length were installed. Water potential and water content were varying by raising and lowering the water table in the column. Moisture and pressure profiles versus time as well as boundary characteristic curves of hysteresis loop were obtained. The last had good approximation with analytical relationships.