Build your first model

• Open Anaqsim on your computer
• Go to File > Save As
• Give your new model a name

This is where you’ll create the foundation of our model

• Go to the Model Input menu > Domains > Confined/Unconfined
• Fill in the input boxes as below
• Click Save (File > Save)

Now you have a 23m thick unconfined aquifer. Don’t worry about the “average head” value – It’s just a starting point that you can easily change

Now we will define the aquifer’s shape – which is simply the classic box for this model.

Defining head-specified boundaries (east and west boundaries)

• Go to Model Input > Line Boundaries > Head Specified
• Add two boundaries by copying the details below (to copy the co-ordinates to your clipboard, click the relevant link). All other boxes can be left as default values
• Click Save (File > Save)

Copy co-ordinates for upstream boundary

Copy co-ordinates for downstream boundary

Defining no-flow boundaries (north and south boundaries)

• Go to Model Input > Line Boundaries > Normal Flux Specified
• Repeat the process of copying and pasting co-ordinates and other boundary details
• Click Save

Copy co-ordinates for northern no-flow boundary

Copy co-ordinates for southern no-flow boundary

Adding wells

Let’s add some action to our model!

• Go to Model Input > Pumping Wells > Discharge-Specified
• Add two wells: one injection well and one production well
• Copy the details from the image below (not positive and negative signs)
• Click Save

For the classic box model, precipitation recharge is usually ignored. So we will not add recharge, but go through the steps and add zero recharge so you get familiar with the process.

• Go to Model Input > Area Source/Sink > Uniform, Domain

You have built your first model. Now for the exciting part!

• Click Solve on the main menu bar

Anaqsim will run the simulation instantly. Look at the run log to see the simulation documented. That’s it – the model is complete!

This is where you get to see your model come to life!

• Anaqsim’s Plot view starts with a blank slate, so let’s tell it what to display. Go to Plot Input > What to Plot and check the boxes for ‘Contours’ and ‘Vectors’
• Click Make Plot > All Selected Features Same Level / Time

You should now see the simulated interaction between the injection and production wells within the groundwater flow field you defined