Assessment of statistical models for indirect determination of permeability functions from soil–water characteristic curves

Water coefficients of permeability are commonly obtained for saturated soils. The water coefficient of permeability of unsaturated soil is best determined by direct measurement: for instance by means of a rigid-wall or flexible-wall permeameter. However, the test is time consuming, labour intensive and tedious. Statistical models have been shown to be the most rigorous indirect method for determining the permeability functions of unsaturated soils. The models use a statistical consideration for the distribution of pores and their interconnectivity. The input required for the models comprises the soil–water characteristic curve (SWCC) and the saturated water coefficient of permeability. Good agreement between...