Flow alteration impacts on Hudson Bay river discharge
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Date
2018-09-22
Authors
Dery, Stephen J.
Stadnyk, Tricia A.
MacDonald, Matthew K.
Koenig, Kristina A.
Guay, Catherine
Journal Title
Journal ISSN
Volume Title
Publisher
John Wiley and Sons, Ltd
Abstract
This study explores flow regulation controls on daily river discharge variations and
trends into Hudson Bay from four highly regulated and 17 moderately regulated/
unregulated systems over 1960–2016. These 21 rivers contribute ~70% of the total
annual riverine freshwater export to Hudson Bay, with highly regulated and moderately
regulated/unregulated rivers accounting for 47% and 53% of the discharge,
respectively. Daily observed streamflow data from the Water Survey of Canada,
Manitoba Hydro, Ontario Power Generation, and Hydro‐Québec are used. Decadal
hydrographs of the mean and coefficient of variation of daily river discharge are
developed to assess the changing hydrological regimes in both systems. Decadal spectral
analyses reveal the dominant controls on daily river discharge input to Hudson
Bay from the regulated and unregulated systems. Apart from expected peaks in
spectral power on annual timescales arising from the nival regimes in both systems,
a strong secondary peak emerges at weekly timescales from flow regulation due to
hydropower production. Hydrographs that consider the day of the week reveal
distinct weekly cycles in regulated rivers with ~10% declines in daily river discharge
during weekends and statutory holidays relative to weekday averages, demonstrating
the importance of regulation on the timing of freshwater into Hudson Bay.
Description
Keywords
Climate Change, flow regulation, Hudson Bay, James Bay, Hydropower, pan-Arctic river discharge, streamflow, water resources
Citation
Déry SJ, Stadnyk TA, MacDonald MK, Koenig KA, Guay C. Flow alteration impacts on Hudson Bay river discharge. Hydrological Processes. 2018;1–12. https://doi.org/10.1002/hyp.13285