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Performance Analysis of the χMD Matrix Solver Package for MODFLOW-USG
Motomu Ibaraki1, Yiding Zhang2, Richard G Niswonger3
1School of Earth Sciences, The Ohio State University, Columbus, OH, 43210.
Ground Water
|May 12, 2021
Summary
Optimizing the χMD matrix solver for groundwater modeling requires careful selection of preconditioning parameters. Specific incomplete lower-upper (ILU) factorization levels and drop tolerance values significantly enhance computational efficiency and robustness.
Area of Science:
- * Computational hydrogeology
- * Numerical methods in environmental modeling
Background:
- * The χMD matrix solver is integrated into U.S. Geological Survey (USGS) groundwater modeling software like MODFLOW-USG.
- * It solves matrices from groundwater flow and solute transport equations, offering improved performance over existing solvers.
Purpose of the Study:
- * To investigate the impact of preconditioning parameters on χMD solver performance.
- * To identify optimal parameters for enhanced execution speed and memory efficiency in groundwater modeling.
Main Methods:
- * Evaluated five groundwater models with varying numerical complexities using MODFLOW-USG.
- * Analyzed the effect of incomplete lower-upper (ILU) factorization levels and drop tolerance values on solver performance.
- * Tested models with 10,000 to 730,300 discretization nodes.
Main Results:
- * Preconditioning parameters significantly influence execution times and memory usage.
- * Optimal performance was observed with ILU levels between five and seven and drop tolerance values between 10⁻² and 10⁻³.
- * These parameter ranges generally led to shorter overall execution times.
Conclusions:
- * Users can achieve higher performance and robustness from the χMD solver by applying specific parameter combinations.
- * This optimization enhances the computational efficiency of solving groundwater flow and solute transport problems.
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