Hierarchical Modeling and Parameter Estimation for a Coupled Groundwater–Lake System

Abstract

In this paper, a generalized hierarchical multiscale approach for modeling coupled groundwater and surface water systems is demonstrated. Groundwater–lake interactions are simulated by coupling the groundwater equations with the lake’s continuity equation and by providing a two-way iterative feedback between models at multiple scales using specified head/flux boundary conditions. A hierarchical parameter estimation method that allows data and parameters at different scales to communicate between each other is also developed. These methods are applied to simulate a lake augmentation system for the Sister Lakes in southwest Michigan, which involves pumping a large amount of water from an irrigation well into the lakes. This problem requires resolution of time scales ranging from site-scale (hours) to local-scale (months) to watershed-scale (years) and spatial scales ranging from a few meters to a few kilometers. A hierarchical modeling framework consisting of five interlinked models was created, and model calibration was performed using drawdown data from a 72-h pumping test. The calibrated model was then used to simulate the entire lake augmentation system. The results indicate that the proposed modeling and parameter estimation approach can help improve the ability to model real-world complexities.