Check 5 - Uniform flow in a confined interface aquifer with uniform recharge
Checks confined interface domain, constant head line boundary, normal flux line boundary, uniform recharge, 3D pathlines
This is the same as check 2, but with a confined interface aquifer instead of a confined one. The top of of the domain is at –
The salt water elevation is 0.0 and the ratio of salt/fresh density is 1.025 (40:1 ratio of interface depth to head height).
At the left edge of the model, the head is 3.0 and at the right edge head is 0.3 (just above 0.25, the head where the interface would intersect the top of the domain and make it have zero saturated thickness). At the left side of the domain there is no interface, the domain is confined and the domain discharge is about 0.189.
For x > 450, the domain has an interface that rises near to the top of the domain at the right side of the model. At the right side, the head is 0.30, and the interface is at –
Checks of the interface and head at other points where the interface exists show this same ratio. The recharge adds 0.50 as the pathline crosses the model from left to right, so the total discharge increases to 0.689 at the right side, as it should.
The fractional discharge above the pathline at the right side of the model is 0.5/0.689 = 0.73.
Checking the specific discharge, average linear velocity, saturated thickness, head, and interface elevation anywhere shows that Darcy’s law and the Ghyben-