Ground-Water Model Instructions

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Development in progress

1 Mesh
- 1.1 Mesh generator
2 Matrix solvers
3 Groundwater model
- 3.1 Testing
  - 3.1.1 Free-surface, steady-state

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Mesh

The mesh_cx.py file contains two classes designed to create a numerical mesh based on the presence of geologic layers.

Classes:

mesh_cx: An x,z mesh
layer: A container to hold information about each layer.

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Mesh generator

The mesh generator attempts to create block centered cells with the cell boundaries at the the boundaries between layers.

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Matrix solvers

Sometimes explicit solutions are just not enough. I've created 3 simple matrix solvers (Jacobi, Gauss-Seidel, sor) written entirely in Python and not optimized.

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Groundwater model

The numerical model uses a mesh_cx class as the input for the numerical mesh and material properties.

Assumptions:

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Test of model solving for a free surface with complex stratigraphy (groundwater_fs_ss_test.py). Lowest unit has a relatively low hydraulic conductivity.

Higher resolution free-surface, complex (uniform) stratigraphy simulation. (groundwater_fs_ss_test.py). Lowest unit has a relatively low hydraulic conductivity. Base code -> groundwater_fs_ss_test.py; line 33 -> nrows = 50; line 34 -> ncols = 50

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Relative conductivity of units.

Base code: Media:Gwmodel free surface ss.tgz

Hydraulic conductivities	Giving the lowest unit a high hydraulic conductivity. Base code -> groundwater_fs_ss_test.py; line 91; layers[0].add_prop("K", 0.0025)	Giving the middle unit a high hydraulic conductivity. Base code -> groundwater_fs_ss_test.py; line 91; layers[1].add_prop("K", 0.0025)	Giving the uppermost unit a high hydraulic conductivity. Base code -> groundwater_fs_ss_test.py
Heads	Giving the lowest unit a high hydraulic conductivity.	Giving the middle unit a high hydraulic conductivity.	Giving the uppermost unit a high hydraulic conductivity.Note that too stringent of a tolerance on the solver results in the solution oscillating about this final result; tol=1e-4; dzmax=0.01. This is likely due to the fact that the watertable crosses two different hydraulic units.