Comparison of two modeling approaches for groundwater–surface water interactions

• DOI: 10.1002/hyp.9323
• Publication Date: 2012-04-04T17:51:43Z
• Authors: C. Guay; M. Nastev; C. Paniconi; M. Sulis
• Keywords: Groundwater model; Infiltration (HVAC); Subsurface Flow; Groundwater discharge

Abstract An assessment of interactions between groundwater and surface water was carried out by applying two different modeling approaches to a small‐scale study area in the municipality Havelock, Quebec. The first approach involved commonly used sequential procedure that consists determining daily recharge rate using quasi 2D infiltration model (HELP), applied next step as an imposed flux 3D finite‐element flow model. calibrated under steady‐state transient conditions against measured levels. second based on recently developed physically based, fully coupled groundwater–surface (CATHY) entire domain integrated manner. Implementation, calibration, results simulations for both are presented discussed. For equal annual precipitation (1038 mm/y) evapotranspiration (556 mm/y), computed 233 mm/y (8.9% higher than approach) net upward from fractured aquifer (the predicted downward rock). simulated discharge similar (9.6% difference). Both were found be useful understanding water, although limitations apparent procedure's inability account surface–subsurface feedbacks, instance near stream reaches where is prevalent. decoupled, two‐model provides disaggregated surface, vadose, flows, simple aperçu at components total discharge. accounts continuous exchanges land subsurface, channel more complex manner, produces better match observed data. Copyright © 2012 John Wiley & Sons, Ltd.