MODFLOW Model File Writer

Write a Python script that creates a simple MODFLOW 6 groundwater flow simulation and writes all necessary input files to disk. The simulation should represent a basic confined aquifer with specified boundary conditions.

Requirements

The script should:

1. Create a MODFLOW 6 simulation with a single groundwater flow model
2. Define a structured grid with the following specifications:
   • 3 layers, 20 rows, 30 columns
   • Uniform cell size: 100m x 100m
   • Layer thicknesses: 50m, 30m, 20m (top to bottom)
3. Set up temporal discretization with:
   • 2 stress periods
   • First stress period: 1 day, steady-state
   • Second stress period: 100 days, transient with 10 time steps
4. Configure hydraulic properties:
   • Hydraulic conductivity: 10.0 m/day for all layers
   • Specific storage: 0.0001 (1/m) for transient simulation
   • Specific yield: 0.2 (dimensionless) for layer 1
5. Set initial conditions:
   • Starting head: 100.0 m for all cells
6. Add boundary conditions:
   • Constant head of 100.0 m on the left boundary (column 0) for all layers
   • Constant head of 95.0 m on the right boundary (column 29) for all layers
   • Recharge of 0.001 m/day applied to the top layer for stress period 2
7. Add a solver configuration with default settings
8. Write all simulation files to a directory named model_workspace
9. The script should be executable and create all necessary MODFLOW 6 input files

Output

When executed, the script should create a model_workspace directory containing all MODFLOW 6 input files, including:

• Simulation name file
• Model name file
• Discretization files
• Initial conditions file
• Package files for hydraulic properties, boundary conditions, and solver

Tests

• The script creates a model_workspace directory @test
• The simulation name file exists in the workspace @test
• The discretization package file contains correct grid dimensions @test
• The constant head package file exists and contains boundary conditions @test

Implementation

@generates

API

def create_and_write_model() -> None:
    """Create a MODFLOW 6 simulation with specified parameters and write all files to disk"""
    ...

Dependencies { .dependencies }

flopy { .dependency }

Provides MODFLOW model creation and file writing capabilities.