Interbedding of aquifers and semipervious layers (aquitards)
Types of aquifer
systems to be analyzed:
1) three-layer system consists
of aquifer overlain and underlain by aquitards;
2) two-layer system consists of
aquifer overlain or underlain by aquitards.
Stratified aquifer system: a – three-layer; b – two-layer.
Two sets of
solutions are considered in this section: those developed by M.S.
Hantush and those developed by A.F. Moench. Hantush’s solutions
being simple and based on well-known hydrological functions,
however have a time limitation: they can be applied only for
certain periods of time. Moench’s solutions are more universal:
time-drawdown graph is plotted for the entire time period, drawdown
is calculated for the main aquifer and for adjacent aquitards as
well, storage capacity of the pumping well and skin effect are
taken into account.
Hantush M.S. Modification of
the theory of leaky aquifers // Journal of Geophysical Research.
1960. Vol. 65, N 11. P. 3713–3725.
Moench A.F. Transient flow
to a large-diameter well in an aquifer with storative semiconfining
layers // Water Resources Research. 1985. Vol. 21, N 8.