Infiltration describes the flow of water from the free surface zone to the infiltration zone below the ground level.
This effect may be a relevant factor in flood modelling where even a small precipitation can invoke flow on a dry surface. The effect of infiltration is included by subtracting the net infiltration volume from the volume of water in the individual grid cell. This is similar to a sink effect in the spatial domain however the effect will not affect the overall flow. The resulting water depth can be expressed by
(6.12)
where Vinfiltration is the net infiltrated volume in the grid cell.
