Water-Resources Investigation Report 03-4232
Recalibration of a Ground-Water Flow Model
of the Mississippi River Valley Alluvial
Aquifer in Southeastern Arkansas, 1918-98, with Simulations
of Hydraulic Heads Caused by Projected Ground-Water Withdrawals
through 2049
By Gregory P. Stanton and Brian R. Clark
To evaluate the effects of projected ground water withdrawals,
three scenarios were used to simulate a range of possible withdrawals.
Five additional stress periods of 10 years each were added to the model
to facilitate predictive scenario generation. The predictive scenarios
control pumpage by either continuing 1997 pumpage into the future
(scenario 1) or by increasing water-use trends into the future
(scenario 2 and 3). The ASWCC Critical Ground Water area designation
includes a requirement that a 50-percent saturated formation thickness
be maintained. For this reason, the level of 50-percent saturated
formation thickness is used as a reference surface in the scenario
output presented. Animations of simulated heads changing through time are included on
the compact disc in the "Animations" folder. In the animations,
the level of 50 percent saturated formation thickness is indicated by
a mesh surface and the dry cells appear as voids in the model surface.