The Biscayne aquifer is one of the most permeable aquifers in the world and consists principally of two layers: the Miami Limestone formation and the Fort Thomson formation. In one particular area, the Miami Limestone formation extends from ground surface at 2.44 m NGVD to -3.00m NGVD, and the Fort Thomson formation extends from -3.00 m NGVD to -15.24 m NGVD. The hydraulic conductivity of the Mimai Limestone formation can be taken as 1,500 m/day, and the hydraulic conductivity of the Fort Thomson formation can be taken as 12,000 m/d.
Objectives:
- Calculate the shape of the phreatic surface and the flow between two fully penetrating canals 1 km apart, when the water elevations in the two canals are 1.07 m NGVD and 1.00 m NGVD.
- Solve the problem using MAGNET-IGW
- Solver the problem using MAGNET-MODFLOW
- Solve the problem analytically.
- Compare the results and explain the difference, if any.
MAGNET/Modeling Hints:
- Use ‘Synthetic mode’ in MAGNET to create a model domain.
- Make a 2-layer aquifer model to represent the two formations. Make sure to assign appropriate aquifer elevations and hydraulic conductivity to the different layers.
- Add prescribed head line or zone features along the left and right edges to represent the canals. Note that the canals are fully connected to both layers (they should exist in both model layers).
- Analyze the results in cross-section view ( 'Analysis Tools' > 'Analysis' > 'Display Charts') to visualize the shape of the water table.