|
Parameter
|
Model Layer
|
Adjusted Value
|
Source
|
|---|---|---|---|
|
Natural recharge (in/yr)
|
0.32
|
Estimated during model
calibration with parameter-estimation program.
|
|
|
Anthropogenic recharge
(in/yr)
|
0.67 - 1.8
|
Estimated during model
calibration with parameter-estimation program.
|
|
|
Altitude of starting heads
in feet
|
Layer 3
|
184 - 229
|
Estimated using September
1995 potentiometric map of Memphis aquifer (Kingsbury, 1996).
|
|
Transmissivity, in feet
squared per day
|
Layer 1:
Southwest of
erosional scarp
|
53 - 371
|
Estimated using horizontal
hydraulic conductivity of alluvial-fluvial deposits aquifer determined
by August 1995 aquifer test and thickness of alluvial-fluvial
deposits.
|
|
Northeast of
erosional scarp
|
53 - 265
|
Estimated using horizontal
hydraulic conductivity of upper sand units of Cockfield Formation determined
by specific-capacity tests and thickness of those units in stratigraphic
test holes.
|
|
|
Area of erosional
scarp
|
2
|
Estimated during model
calibration.
|
|
|
Layer 2
|
28 - 300
|
Estimated during model
calibration with parameter-estimation program.
|
|
|
Layer 3
|
not applicable
|
The transmissivity is
irrelevant because layer 3 is a specified head boundary.
|
|
|
Vertical conductance between
layers in feet per day per foot
|
Layer 1:
Buried river valleys
|
4 x 10-4
|
Estimated during model
calibration.
|
|
Fault
|
4.9 x 10-5
|
Estimated during model
calibration with parameter-estimation program.
|
|
|
Elsewhere
|
1 x 10-7
|
Calculated using vertical
hydraulic conductivity of sediment cores and unit thickness with equation
53 (McDonald and Harbaugh, 1988).
|
|
|
Layer 2: Fault
|
4.9 x 10-4
to
4.9 x 10-3
|
Estimated during model
calibration with parameter-estimation program.
|
|
|
Window in
confining unit
|
8.8 x 10-5
|
Estimated during model
calibration with parameter-estimation program.
|
|
|
Elsewhere
|
1 x 10-6
|
Calculated using vertical
hydraulic conductivity of sediment cores and unit thickness with equation
53 (McDonald and Harbaugh, 1988).
|