XPRafts provides for leakage from basins and reservoirs in addition to evaporation losses and conventional outflow. Three strata situations are presently covered. These include a Shallow Water Table, Deep Water Table and Clogged Surface Layer. The equations utilise the work of Bouwer (1978), Bear et al (1968) and Todd (1980) to define shallow water table situations. The methods prescribed are similar to those utilised by Main Roads (Western Australia) PC SUMP(C) software.
Basin Infiltration Rate
Discharge through basin floor infiltration expressed in m/hr. This value represents the hydraulic conductivity of the basin floor.
Thickness of clogged layer in metres. The Permeability value (or infiltration rate) in m/hr should now relate to this clogged layer.
Depth of water table below the invert of the basin in metres. This option is only required if the 'Shallow water table' flag is turned ON.
Shallow Water table
Select this option to model a shallow water table at the given depth. If this flag is off then a deep water table is implied with no interaction with the infiltration flow.