Soil Heat Processes > Soil frost > Theory > Influence of ice on water flows
Water potential

The ice in the soil will affect water potential in two ways. First of all the water potential is influenced because of the freezing that will change the amount of unfrozen water. This primarily effect is governed by the switch FrostInteract. If this switch is off, the water potentials will be considered as if all water was unfrozen.

The water potential can also be affected by the load of the soil above the layer where water is located (see switch LoadPotential). When the load potential is accounted for, the water potential of the soil above a specific layer is calculated as:

                                        (1.37)

where ψ* corresponds to the water potential not affected by the load, θi is the volumetric ice content, fa is the volumetric air content (i.e. θs - θ), z is the depth of the layer and the constant 200 is assumed based on an average wet bulk density of 2 g/cm3.