User's guide of Proceessing Modflow 5.0

Processing Modflow 259
6.2.8 Simulation of Lakes
Folder: \pm5\examples\basic\basic8\
Overview of the Problem
Fig. 6.32 shows an unconfined aquifer with the boundary conditions and the location of a
planned open-cast mining site. The aquifer is bounded by a no-flow zone to the north and to the
south. To the west and east exist fixed-head boundaries with the hydraulic heads h = 100 m and
50 m; the elevations of the aquifer top and bottom are 100 and 0 m, respectively.
The aquifer is homogeneous and isotropic with a measured horizontal hydraulic
conductivity of 0.0001 m/s and vertical hydraulic conductivity of 0.00001 m/s. The specific
yield and effective porosity are assumed to be 0.25. The specific storage coefficient S = 0.0001.
s
In the final mining phase, the hydraulic head within the mining site must be drawn down at
the level of h = 21 m. Afterwards, the mining site will be filled with water to form an artificial
lake. Your task is to
1. construct a steady-state flow model and calculate the necessary abstraction rate (= inflow
into the mining site) for holding the head at 21 m, and
2. use the calculated steady-state head as the initial hydraulic head and calculate the temporoal
development curve of the water level (head vs. time) in the artificial lake for the case that
the abstraction within the mining site is turned off.
Fig. 6.32 Plan view of the model area
6.2.8 Simulation of Lakes