M. Heinen et Pac. Raats, Unconventional flow of water from dry to wet caused by hysteresis: A numerical experiment, WATER RES R, 35(8), 1999, pp. 2587-2590
We demonstrate with the help of a numerical simulation model for hysteretic
water movement that for horizontal redistribution three types of flow can
occur. Raats and Iran Duijn [1995] previously identified these types as a r
eaction to a specific analysis by Philip [1991]. Depending on the initial c
onditions in two parts of an infinitely long soil column, there can be no f
low, conventional flow from the wet part to the dry part, or unconventional
flow from the dry part to the wet part. When flow occurs, the cumulative w
etting and cumulative drying both show the expected linear relationship wit
h the square root of time. Hysteresis is described according to the modifie
d dependent domain model of Mualem [1984]. We also indicate that Kool and P
arker [1987], who used this model as well, presented a erroneous expression
for the differential moisture capacity of the scanning drying curve.