Characterization of unsaturated hydraulic parameters for homogeneous and heterogeneous soils

Field soils are inherently heterogeneous in their hydraulic properties, which has a large impact on flow and contaminant transport. Hence there is a need to develop techniques for developing fast and reliable techniques for estimating these properties in the form of the retention and hydraulic conductivity functions. A method was developed that combines a flowpump technique for direct measurement of the retention characteristics and an inverse technique for indirect estimation of the hydraulic conductivity function. To investigate the influence of spatial heterogeneity on flow and transport controlled experiments were carried out in laboratory tanks. The collected data were also used for evaluating the performance of effective parameters representing the integrated behaviour of the heterogeneous systems.