LeachMod is designed to simulate the depth of the water table and the
soil salinity in irrigated areas with a time step as selected by the user
(from 1 day to 1 year). The program uses small time steps in its
calculations anyway for a better accuracy.
In case of a leaching experiment with measured soil salinities, LeachMod
can automatically optimize the leaching efficiency by minimizing the sum
of the squares of the differences between measured and simulated
The root zone can consist of 1, 2, or 3 layers.
LeachMod allows the introduction of a subsurface drainage system in
a transition zone between root zone and aquifer, and subsequently it
determines the drain discharge.
When the irrigation/rainfall is scarce and the water table is shallow,
LeachMod will calculate the capillary rise and reduce the potential
evapotranspiration to an actual evapotranspiration, although the
reduction may be diminished by the capillary rise.
LeachMod can also take into account upward seepage from the aquifer
or downward flow into it. The latter flow is also called natural subsurface
This model is somewhat similar to SaltCalc.
On the one hand the water management options are fewer (e.g. re-use of drainage
or well water for irrigation do not feature here), but the model is more modern
in the sense that the variable input for each time step is given in a table so
that the calculations over all the time steps are done in one go. Moreover, by
inserting the observed values of soil salinity in the data table, the model
optimizes the leaching efficiency of the soil automatically.
A version with additional leaching by surface drainage can be made available on
The program starts clicking on LeachMod.Exe.
More information is given in the program itself.
(to be completed)