Abstract
Laboratory experiments using a container filled with glass beads were conducted to investigate the influence of soil water hysteresis on a saturated-unsaturated flow. Water levels of constant head tanks at the right and left boundary of the container were shifted downward first and then upward while the difference of the water levels of the tanks were kept constant. Tracer was injected at several points in the container to monitor saturated and unsaturated flow after steady states were reached at each stage. These experiments showed clear difference in the pattern of tracer trajectories governed by the soil water hysteresis. Numerical simulations including the effect of the hysteresis were also conducted to evaluate the influence of hysteresis on saturated-unsaturated flow. The simulated results matched quite well with the experiments and further were used to calculate velocity vectors and draw pathlines.
