Three-layer aquifer system
✓aquifer system consists of isotropic aquifer over- and underlain by aquitards;
✓main aquifer contains the pumping well;
✓adjacent aquifers occur on top (overlying) or bottom (underlying) of the aquifer system, the overlying aquifer being confined or unconfined;
✓boundary: aquifer system is of infinite lateral extent;
✓pumping well is fully penetrating located in the main aquifer;
✓drawdown is calculated at any distance from the pumping well in the main aquifer, and for Moench’s solutions – in aquitards also;
✓crossflow in aquitards is vertical;
✓storage in aquitards is included.
Three geological options are considered:
option 1: aquifer system is over- and underlain by aquifers with constant water levels (a, b);
option 2: aquifer system is over- and underlain by aquicludes (e);
option 3: aquifer system is underlain by aquiclude and overlain by aquifer with a constant water level (c, d), or by contrast, aquifer system is underlain by an aquifer with a constant water level and overlain by aquiclude (f).
Conceptual schemes of leaky aquifer system (three-layer aquifer system) with account for storage of the aquitards.
The following cases are considered depending on boundary conditions on top and bottom of the aquifer system: a, b – aquifer system is over- and underlain by aquifers with constant water levels, those aquifers being either confined (a) or unconfined(b); c, d – at the top of the aquifer system occurs an aquifer with a constant water level either confined (c) or unconfined(d), and at the bottom occurs and aquiclude; e – aquifer system is over- and underlain by aquicludes; f – aquifer system is overlain by an aquiclude and underlain by an aquifer with a constant level.
Cross section of a leaky aquifer system (three-layer aquifer system) with account for aquitard storage capacity for Moench’s solutions. All cases of aquifer/aquitard position described above are available.
One or several wells pumped at a variable rate