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).
program uses small time steps in its calculations
anyway for a better accuracy.
In case of a leaching experiment with measured
salinities, LeachMod can automatically optimize
the leaching efficiency by minimizing the sum of
the squares of the differences between measured
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
capillary rise and reduce the potential
evapotranspiration to an actual evapotranspiration
that, although the reduction may diminish by the
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
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
On 11 July 2015 LeachMod was updated to include
more rigorous data checks.
On 7 April 2016 the program was updated again and
the initial soil salinity can now be be introduced
for the various rootzone layers separately instead
of one value for the whole rootzone.
On 3 march 2017, the distribution of the
evaporation over the various rootzone layers was
refined, leading to a small change in the salt
distribution over these layers.
The program starts clicking on LeachMod.Exe.
More information is given in the program itself.
A description of the principles of water and salt
balances in the soil on which LeachMod is based is
to be found on this