Contaminant Transport Simulation

Overview

Implement a groundwater transport simulation to model the movement of a contaminant through an aquifer. The simulation should track how a contaminant plume spreads from a continuous source over time.

Requirements

Model Domain

Create a simple 2D transport model with the following specifications:

• Grid Dimensions: 10 rows × 30 columns × 1 layer
• Cell Size: 10 meters in both horizontal directions
• Layer Thickness: 10 meters
• Simulation Duration: 1000 days with 100 time steps

Transport Parameters

• Initial Concentration: 0.0 mg/L everywhere
• Porosity: 0.3
• Dispersivity:
  • Longitudinal: 5 meters
  • Transverse horizontal: 0.5 meters

Contaminant Source

Apply a constant concentration boundary representing a contamination source:

• Location: Cells at column 0, rows 4-6 (left boundary, center)
• Concentration: 100 mg/L
• Duration: Entire simulation

Flow System

For this simplified model, assume a uniform groundwater velocity of 0.1 m/day flowing from left to right (west to east).

Implementation Tasks

1. Set up a simulation with temporal discretization for the specified duration
2. Create a transport model with appropriate spatial discretization
3. Configure advection to represent solute movement
4. Set up dispersion with the specified dispersivity parameters
5. Apply the constant concentration boundary at the source location
6. Configure initial concentration conditions
7. Write the simulation files to a workspace directory

Output

Your implementation should create all necessary input files in a workspace directory. The model should be configured to track concentration over time as the plume migrates downgradient.

Test Cases { .testcases }

Test 1: Verify Grid Dimensions { .testcase }

@test

Input: Read the created spatial discretization configuration

Expected Output:

• Grid has 10 rows, 30 columns, and 1 layer
• Cell dimensions are 10m × 10m

Test 2: Verify Simulation Duration { .testcase }

@test

Input: Read the temporal discretization configuration

Expected Output:

• Simulation period is 1000 days
• Configured with 100 time steps

Test 3: Verify Source Configuration { .testcase }

@test

Input: Read the constant concentration boundary data

Expected Output:

• Source cells are at column 0, rows 4, 5, and 6
• Concentration value is 100 mg/L

Dependencies { .dependencies }

flopy { .dependency }

Python package for creating MODFLOW-based groundwater models. Use this to build the groundwater transport simulation.