Category: MIGRATE Examples
Posts
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MIGRATEv10 Example 1: Modeling a RCRA Subtitle D Landfill with a Composite Liner
Introduction MIGRATEv10 Example 1 demonstrates how to model contaminant migration from a U.S. RCRA Subtitle D landfill using a composite liner system and a primary leachate collection system (PLCS). This example is foundational for understanding how engineered barriers control leakage and how contaminants move into underlying groundwater systems. The simulation focuses on a volatile organic…
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MIGRATEv10 Example 2: Composite Liner System with Primary & Secondary Leachate Collection
Introduction MIGRATEv10 Example 2 builds on the fundamentals introduced in Example 1 by incorporating a more advanced landfill design that includes: This example demonstrates how multiple engineered barriers work together to minimize contaminant migration and how MIGRATEv10 models leakage and transport through a layered system. Conceptual Model Overview The modeled landfill system includes: This multi-barrier…
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MIGRATEv10 Example 3: Pure Diffusion of a Conservative Contaminant
Introduction MIGRATEv10 Example 3 presents a simplified but highly instructive case of pure diffusion of a conservative contaminant through a porous medium. Unlike previous examples, this scenario excludes: This makes it an ideal example for understanding the fundamental physics of diffusion-controlled transport in subsurface environments. Conceptual Model Overview The modeled system consists of: Key Simplification…
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MIGRATEv10 Example 4: Finite Mass Source and Aquifer Mixing with Base Outflow
Introduction MIGRATEv10 Example 4 builds directly on Example 3 by introducing two critical real-world complexities: This example provides a more realistic representation of landfill behavior by simulating how a limited contaminant mass evolves over time and how it is diluted within a flowing aquifer. ⚠️ Important: This example highlights key hydrogeologic assumptions. Proper application requires…
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MIGRATEv10 Example 5: Understanding Integration, Accuracy, and the Role of Engineering Judgment
Introduction MIGRATEv10 Example 5 is less about a specific landfill configuration and more about how to use the model intelligently. It emphasizes two critical aspects of contaminant transport modeling: This example highlights that modeling is not just about running software—it’s about understanding when results can be trusted and when additional effort is required. Conceptual Overview…
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MIGRATEv10 Example 6: Eliminating Negative Concentrations Through Improved Integration
Introduction MIGRATEv10 Example 6 builds directly on Example 5 by addressing a common numerical issue in contaminant transport modeling: 👉 Negative concentrations and flux values These results are non-physical and indicate that numerical integration parameters need adjustment. This example demonstrates how to refine the solution by modifying key Talbot integration parameters, and optionally verifying results…
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MIGRATEv10 Example 7: Improving Accuracy with User-Selected Fourier Integration
Introduction MIGRATEv10 Example 7 continues the refinement process from Examples 5 and 6 by addressing a persistent issue: 👉 Negative concentrations in the upper 5.6 m of the model domain In this case, the focus shifts from Talbot integration to Fourier integration, specifically how user-selected Gauss integration parameters can significantly improve model accuracy. This example…
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MIGRATEv10 Example 8: Evaluating Contaminant Migration at Multiple Lateral Positions
Introduction MIGRATEv10 Example 8 introduces an important advancement in contaminant transport analysis: 👉 Evaluating concentration at multiple lateral positions Rather than focusing on a single point, this example investigates how a pollutant migrates outward from a buried landfill and how concentrations vary at different distances from the source. This approach provides a more realistic understanding…
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MIGRATEv10 Example 9: Comparison with the TDAST Analytical Solution
Introduction MIGRATEv10 Example 9 focuses on model validation by comparing numerical results from MIGRATEv10 with an established analytical solution. The benchmark used is TDAST, a program developed by Javandel et al. (1984) for solving 2-D plane dispersion in infinitely deep porous media. This example demonstrates how closely MIGRATE can reproduce analytical solutions and provides confidence…
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MIGRATEv10 Example 10: Contaminant Transport in Fractured Media with Sorption
Introduction MIGRATEv10 Example 10 introduces a more advanced and realistic scenario by incorporating: This example builds on earlier cases by modeling contaminant migration through a landfill barrier system that includes both compacted clay and a fractured till layer, while accounting for retardation due to sorption. It also serves as the 2-D extension of a similar…