(l) Modelling of the water balance of the unsaturated zone and (2) calculating the Darcian flux have been applied for determining groundwater recharge. Modelling was based on field and laboratory studies, including soil moisture measurements, infiltration experiments, textural analysis and retention measurements. Method (l) is not particularly sensitive to the uncertainty in the characterization of the soil properties and is dependent on reliable estimates of surface fluxes. Method (2) on the other hand is very sensitive to changes in soil physical parameters. Although it seems straightforward it gives more uncertain estimates of groundwater recharge than a simulation model of the soil water balance.
Groundwater recharge of fluvial deposits at Haslemoen, Solør, southeastern Norway