HGS RESEARCH HIGHLIGHT – Estimation of groundwater contributions to Athabasca River, Alberta, Canada
Hwang, H.-T., Erler, A. R., Khader, O., Berg, S. J., Sudicky, E. A., & Jones, J. P. (2023). Estimation of groundwater contributions to Athabasca River, Alberta, Canada. In Journal of Hydrology: Regional Studies (Vol. 45, p. 101301). Elsevier BV. https://doi.org/10.1016/j.ejrh.2022.101301
Integrated surface-subsurface model for the Athabasca River Basin
This new study co-authored by Aquanty scientists evaluates the influence of surface water-groundwater interactions within the Athabasca River Basin (ARB). The study builds on earlier basin-scale integrated surface-subsurface model of the ARB by Aquanty staff. The calibrated model was paired with gridded climate data from the Climate Research Unit (CRU) dataset and utilized HGS’s built-in snow melt and accumulation features to evaluate snowmelt runoff (an extremely important hydrologic mechanism in this permafrost region). Using the calibrated model, groundwater contribution to surface flow in the Athabasca River was determined based on simulated surface water-groundwater exchange fluxes. The results showed that groundwater does have a high interaction rate with the river, 34% in high-flow seasons and 63% in low-flow seasons, averaging out to 45% over the year.
This research provides important insights for policy makers to protect ecosystems and water supplies. The ARB covers a vast part of Alberta (160,000 sqkm) and has a massive impact on a wide array of ecosystems and the local (and national) economy. Given its importance, this study demonstrates why groundwater/surface water interaction should be included in climate change and water availability analyses. The fully integrated nature of HydroGeoSphere was a key contributor to this study, as these simulations allowed for clear accounting of the interaction between groundwater and surface water, while also incorporating influential hydrologic mechanisms like snowmelt/accumulation and evapotranspiration over a very large area.
Mean net exchange fluxes based on monthly transient simulations: a) average annual, b) low flow season (May to September), and c) high flow season (October to April).
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Abstract:
Study region: The Athabasca River Basin (ARB), Canada
Study focus: This study investigates the dynamic interactions that occur between surface water and groundwater systems within the Athabasca River Basin (ARB). The integrated surface-subsurface model of the ARB was first calibrated under monthly normal transient flow conditions to observed surface water and groundwater data, after which the model was forced with monthly average transient data to evaluate model performance. From these results, groundwater contribution to the Athabasca River system was calculated using simulated surface water-groundwater exchange fluxes. These estimates are compared to those obtained from an isotope-based balance analysis which also estimated groundwater contribution to the Athabasca River.
New hydrological insights for the region: The results from this study suggest that the groundwater system in the basin has a high degree of interaction with the surface water system. Specifically, the groundwater contribution to the surface water system along the Athabasca River ranges from 34% (high flow season) to 63% (low flow season) with an overall average annual groundwater contribution of 45%. These results indicate that the groundwater system needs to be considered when analyzing potential climate change impacts on future water availability and extreme hydroclimatic events.