Simulation of Distributed Base Flow Contributions to Streamflow Using a Hillslope-Based Catchment Model Coupled to a Regional-Scale Groundwater Model

Abstract

AbstractThe estimation of base flow contributions to streamflow, and in particular the partitioning of base flow into shallow and deep aquifer components, is a challenging problem in water resources management. In this study, the newly developed hillslope-storage Boussinesq analytic-element (hsB/AE) model is applied to the Allen River headwater catchment in southern Quebec, Canada, which is a major recharge area for the transboundary Chateauguay River watershed. This first application to a real catchment serves as an illustration of the basic principles behind the coupled model and an investigation into interaquifer interactions and the origins of base flow contributions to streamflow. The hsB component of the model represents local groundwater flow in sloping, shallow Quaternary sediments, whereas the AE component represents the underlying regional bedrock aquifer. The catchment is partitioned into hillslopes of regular convergent, divergent, or combined planform shapes. Simulations are run for the summe...