Model Calibration Techniques for Use with the Analytic Element Method

The combination of the analytic element method and a nonlinear parameter estimation technique forges a computationally efficient, information‐rich, and cost‐effective solution to the inverse ground‐water flow problem. The recommended model calibration method uses a nonlinear least‐squares objective, as quantified by misfitting the measured and modeled heads, and a modified Levenberg‐Marquardt algorithm. As detailed and demonstrated by a steady‐state regional aquifer model of Bemidji, Minnesota, automated calibration techniques make ground‐water modeling feasible for a wider variety of projects where tight budgets and a lack of tools may have previously made such modeling inappropriate.