Non-continuous unsteady flow in unsaturated porous materials is defined and it is shown that time-dependent problems of this type, having varying bnoundary conditions, are represntative of many commonly occurring complex field situations. Experimental design and construction with literature review. Drainage of an initially saturated sand column to atmosphere at its base is studied from experimental and analytical viewpoint noting the hydrological characteristics of the sand fraction under dynamic conditions. Comparison of measured and computed moisture profiles. The form of the hysteresis behaviour of the sand fraction under wetting and drying is measured and the effect of pore-air compression, during rewetting under excess surface water, on both infiltration and drainage is described. A numerical approach to solve this problem is suggested.