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AnAqSim (analytic aquifer simulator)


Gain more insight in less time

A quick alternative to MODFLOW and other numerical methods for modeling cases that range from simple to moderately complex.

Comprehensive capabilities

AnAqSim is sophisticated and capable analytic element software:  multi-layer 3D systems, full transient capabilities, heterogeneity, anisotropy, fresh-salt interface aquifers, and a full suite of line boundary types.

Many uses

AnAqSim has been used to simulate groundwater remediation designs, mine and construction dewatering, infiltration mounding, regional aquifer flow, capture zones, well field impacts, fresh/salt interface flow in coastal aquifers, pathlines, advective transport, and embankment seepage.


 Video overview of AnAqSim:

Features gallery (click on images to enlarge)

Heads and pathlines in 4-layer model of collector well near a river bank

3D pathlines are traced from a line, with arrows at each year of travel. All pathlines are captured by the horizontal arms of the collector well.  The collectors are in layer 3 and some extend out under a river to the right. The uppermost domain to the left is unconfined with recharge.  To the right under the river it is confined with leakage to the riverbed.

Vertical profile of pathlines and heads in 4-layer model of collector well

3D pathlines are shown for the collector well model (see plan view image to left).  Layer boundaries are shown in gray, heads in blue, and pathlines in red.  Horizontal collector well arms are in the thin 3rd layer.

Vertical profile of simulated fresh/salt interface

AnAqSim model with two aquifers separated by an aquitard.  Results are compared to SEAWAT and MODFLOW (SWI) results for the same veritcal profile.

Flexible Layering

Vertical profile through a multi-layer 3D model shows how the layering scheme can change from one area of the model to another.  In this case, the lower yellow domain connects to the two lowest green domains and the upper yellow domain connects to the upper two green domains. Discharge and heads are matched where domains connect.  This allows you to concentrate detail and computational effort in the area of interest.

Transient head profiles on a line that crosses a dewatering trench.

This transient multi-layer model simulates response to sudden dewatering to a fixed head along the trench.  AnAqSim produces such plots directly.


Head at well vs. time in transient dewatering simulation

Head declines as dewatering system lowers area heads.  AnAqSim produces such plots directly.


River reach discharge vs. time in transient dewatering simulation

Discharge to nearby river reach declines during simulation of dewatering system.  AnAqSim produces such plots directly.



Simulated heads and velocity vectors in an anisotropic model

Model is 3-layer in the central polygon area with a well screened in the bottom layer.  Aquifer is anisotropic; note that velocity vectors are not always normal to head contours.

Drain line boundary

A polyline drain that transmits water, but has user-specified conductance.  Flow along drain is proportional to gradient and the conductance.



Impermable line boundary

AnAqSim can also simulate leaky barriers.  This aquifer is anisotropic, hence the pathlines are not everywhere normal to the head contours.



Detailed check of line boundary condition

AnAqSim generates plots like this to check the accuracy of line boundary conditions along a line segment.  This shows the accuracy of head continuity along an interdomain boundary with one domain on one side and three domains (3 layers) on the other.




Check of all specified boundary conditions

AnAqSim can check every specified boundary condition and compare them to user-specified tolerances. In this case, the few conditions listed did not meet specified tolerances.

Easily view and edit input data

AnAqSim model inputs and plot inputs are accessed with intuitive data tables.

Use basemap to digitize elements

Basemap is shown in gray, but could also be shown in color.  Model elements, shown in green, have been digitized with the mouse over the basemap.

“Snap-To” digitizing using a basemap

When digitizing, you have the option of snapping to elements, other digitized features, or an imported basemap.  The yellow line is being digitized and it is snapping to an existing vertex (orange square) in the basemap.

Pop-up text boxes give details

As you hover the mouse over line boundaries, text boxes pop up to give details.  This also occurs with pathline arrows, where details are given about the elevation and elapsed time.

Learn more.

Check AnAqSim’s specifications, check articles and books on methods, read the User Guide, or watch tutorial videos.



Try it.

Download and test the free educational version AnAqSimEDU or request a 7-day trial license to check out the full version of AnAqSim.