Conceptual models

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Conceptual models

ANSDIMAT provides analytical interpretation of aquifer tests for the following hydrogeological conceptual models:


1. Confined aquifer (fully penetrating well)

2. Point source (confined aquifer: partially penetrating well)

3. Line source (confined aquifer: partially penetrating well)

4. Unconfined aquifer

5. Leaky aquifer

6. Two-layer aquifer

7. Stratified aquifer systems (pumping from one aquifer)

8. Multilayered systems (pumping from up to 5 pumping aquifers)

9. Areally heterogeneous aquifers

10. Flow test analysis for a well near the river

11. Sloping aquifer

12. Fracture-porous media


13. Horizontal or slanted pumping wells

14. Constant-head test

15. Slug test

16. Evaluation of groundwater response to stream-stage variation


Most models account for the role of lateral and profile boundaries.


The following test stages/periods can be analyzed and interpreted for all conceptual models:

1) pumping (or injection) test,

2) recovery test:

 2.1) the change in the level is counted from the beginning of the test (from the initial /static/ water level),

 2.2) the change in the level is counted from the beginning of the recovery (from the dynamic water level at the moment when the pumping /injection/ is ceased),

 2.3) recovery is analyzed similarly to pumping at a constant rate: the drawdown period is neglected,

3) analysis of the whole test period including pumping /injection/ and recovery stages (drawdown is counted from the initial /static/ water level).

The latter is an analogous to interpreting a pumping test at a variable rate, where the pumping rate during the last step is zero.

Recovery is considered most accurately for a confined aquifer conceptual models. For other conceptual models recovery interpretation is made only by fitting parameters in solving direct or inverse problem. For 2.1 for recovery calculation  function (f) is:

and for 2.2 it is:

For example