Vertical hydraulic gradients governing the rates of infiltration and exfiltration assess the exchange of water between the surface and the subsurface. Fig. 9 presents time-series of the hydraulic gradient at several cross-shore locations for the 1.5 mm and the 8.5 mm beaches. Note that the results are given relative to time t0, which is the bore arrival time at each cross-shore location, and only while the wetting front is still moving towards the groundwater table. Positive gradients are associated with infiltration.
beach
1.5 mm and the 8.5 mm
mm