Infinite leaky aquifer
Assumptions:
üleaky
aquifer system consists of
isotropic aquifers interbedded with aquitards;
ümain
aquifer: the aquifer
that contains pumping well and where the water drawdown is
estimated;
üadjacent
aquifer (may be two
aquifers) water level drawdown is constant during the test
period;
üinitial
water levels in aquifers may
be different or coincide;
üboundary:
aquifer has infinite areal extent;
üpumping
well is fully
penetrating, located in the main aquifer, its storage capacity is
neglected;
üdrawdown
is
estimated in the main aquifer at any distance from the pumping
well;
ücrossflow
through the aquitard is
vertical;
üstorage
of the aquitards is
neglected;
üpumping well
storage capacity may be taken into account (see complementary
solutions below).
a
b
c
d
e
f
Crosssection of the leaky aquifer system with water level in
adjacent aquifers constant during the test period.
a – 3layered confined aquifer system with a leaky roof; b – the
same with a leaky bed; c – 3layered confined aquifer system with
different initial levels in aquifers; d – 3layered unconfined
leaky aquifer system; e, f – 5layered confined (e) and unconfined
(f) aquifer systems with leaky roof and bed. Arrows show flow
direction within layers.
Fundamental equation:
Besides the
fundamental equation the following complementary solutions are
applied:
1)
solution for water level drawdown in the fully penetrating
observation well in the leaky aquifer with allowance for the
pumping well storage capacity
2)
solution for water level drawdown in the pumping well in leaky
aquifer with allowance for the pumping well storage
capacity
3)
Hantush’s solution for the aquifer anisotropic on the lateral
plane
To be analyzed
are:
One well pumped at a constant
rate
Pumping
Recovery
One or several wells pumped at a
variable rate
Pumping
References
Hantush M.S. Analysis of data
from pumping tests in anisotropic aquifers // Journal of
Geophysical Research. 1966. Vol. 71, N 2.
P. 421–426.
Hantush M.S.,
Jacob C.E. Nonsteady
radial flow in an infinite leaky aquifer // Transactions, American
Geophysical Union. 1955. Vol. 36, N 1.
P. 95–100.
Hantush M.S.,
Thomas R.G. A method for
analyzing a drawdown test in anisotropic aquifers // Water
Resources Research. 1966. Vol. 2, N 2.
P. 281–285.
Jacob C.E. Radial flow in a
leaky artesian aquifer // Transactions, American Geophysical Union.
1946. Vol. 27, N 2. P. 198–205.
Lai R.Y.S.,
ChenWu Su. Nonsteady flow
to a large well in a leaky aquifer // Journal of Hydrology. 1974.
Vol. 22, N 3/4. P. 333–345.
