Progress in scientific studies of groundwater in the hydrologic cycle in Canada, 2003-2007

Canadian Water Resources Journal, Summer, 2009 by Masaki Hayashi, Garth van der Kamp

Final Remarks

A brief survey of recent Canadian published studies of groundwater in context of the hydrologic cycle revealed some interesting trends, particularly with respect to the increasing need to integrate our understanding of subsurface hydrology with related disciplines in surface hydrology, soil science, plant physiology, and atmospheric science. Groundwater-surface water (GW SW) interaction continues to be a very active area of research, but the interests in groundwateratmosphere interaction appear to be increasing rapidly, with an emphasis on groundwater recharge and its sensitivity to climate change. Aside from the studies of specific hydrological processes (e.g., GW-SW interaction), a number of studies were conducted to characterize the regional hydrogeology of important aquifers across Canada, providing the background information for sustainable groundwater management. Hydrogeophysics is emerging as an indispensable tool for groundwater hydrology. Advances in sophisticated numerical models have expanded our capability to simulate the integrated groundwater-surface water system and complex reactive transport processes. Combined with more and more sophisticated field instrumentation, these models can potentially fulfill the blueprint for the integration of groundwatersurface water systems, laid out decades earlier by Freeze and Harlan (1969) and Freeze (1974). Despite the progress reported in this article, however, challenges still remain. These include the lack of field data to calibrate and validate models of groundwater recharge and discharge processes over a large scale and long time periods--long enough to examine the effects of land use change and climate change. The uncertainty in model parameters and boundary conditions, and their dependence on spatial and temporal scales, need to be reflected as noted by Freeze (1974, p. 634), "The ultimate modeling goal may well be conceptual models with stochastic variables that correctly reflect the data uncertainties that always exist."These challenges also present new opportunities to integrate groundwater science with other aspects of hydrology and related disciplines using new tools and technologies including advanced instruments for field monitoring, geophysical techniques, remote sensing and GIS, and numerical modelling.

Acknowledgement

We thank the colleagues who sent us their contributions in response to our requests, and Diana Allen and two anonymous reviewers for constructive comments.

Submitted June 2007; accepted February 2009. Written comments on this paper will be accepted until December 2009.

References

Al, T A., K. T. MacQuarrie, K. E. Butler, J.-C. Nadeau, M. R. Dawe, and L. Amskold. 2005. Riverconnected aquifers: Geophysics, stratigraphy, hydrogeology and geochemistry. In Lehr, J. (Ed.) Encyclopedia of Water, John Wiley & Sons, Vol. 5, pp. 677-688.

Alexander, M. D., K. T B. MacQuarrie, D. Caissie, and K. E. Butler. 2003. The thermal regime of shallow groundwater and a small Atlantic salmon stream bordering a clearcut with a forested streamside buffer. Proceedings of the Annual Conference of the Canadian Society for Civil Engineering, GCL-343, 10 pp.