<< Click to Display Table of Contents >> Navigation: ANSDIMAT+ > Aquifer tests analysis > Matching parameters (solving direct problem) > ANSDIMAT+ > Aquifer tests analysis > Matching parameters (solving direct problem) >Unsaturated zone parameters for Moench solution in unconfined aquifer |
The dialog window "Unsaturated zone parameters" is used for entering parameters of variably-saturated zone. The parameters are required for the Moench solution accounting for borehole storage and skin for an unconfined aquifer. Inclusion of unsaturated zone and capillary frindge is optional and allows simulating additional inflow from unsaturated zone during aquifer tests.
The dialog window opens by pressing the button "Parameters" from the dialog window "Matching parameters". The button "Parameters" is enabled if the option "Unsaturated zone" is checked.
Dialog window "Unsaturated zone parameters".
Explanatory table
Abbreviations in the table are the same as used in the USGS computer program that is reported in Barlow and Moench (2011)
Field "Soil-moisture retention exponent" |
Empiric parameter to calculate water saturation in Gardner's solution, 1/m. ACC in program WTAQ version 2 |
Field "Relative hydraulic conductivity exponent" |
Empiric parameter to calculate relative hydraulic conductivity in Gardner's solution, 1/m. AKK in program WTAQ version 2 |
Field "Initial unsaturated zone thickness" |
AMM in program WTAQ version 2 |
Field "Maximum unsaturated zone thickness" |
AXMM in program WTAQ version 2 |
Impact of parameters on solution
AMM >= AXMM |
Infinite thickness of unsaturated zone |
AMM < AXMM |
Finite thickness of unsaturated zone |
ACC approaches infinity |
Unsaturated zone doesn't impact drawdown |
AKK approaches 0 |
Unsaturated zone doesn't impact drawdown |
AMM approaches infinity |
Unsaturated zone doesn't impact drawdown |
ACC <= AKK |
Compulsory condition for the solution |
References:
Barlow P, Moench A.F. WTAQ version 2 - a computer program for analysis of aquifer tests in confined and water-table aquifers with alternative representations of drainage from the unsaturated zone. 2011. U.S. Geological Survey. Technique and Methods 3-B9.