Dec 11, 2025: AB Branch: A Millennium of Hydrological Drought Variability in the Saskatchewan River Basin
Date: Thursday, Dec 11, 2025 – 12 pm MST
Topic: A Millennium of Hydrological Drought Variability in the Saskatchewan River Basin
Speakers: David Sauchyn, University of Regina
Description:
The longest hydrometric records in the Saskatchewan River Basin, exceeding 110 years, do not capture the full range in the severity and duration of hydrological drought. Using a two-stage approach to modelling runoff from tree-ring data, we reconstructed 1000 years of annual and seasonal streamflow at multiple gauges. The two stages – single-site reconstructions and principal component analysis – leverage our network of almost 600 tree-ring chronologies to develop multiple linear regression models that account for up to 80% of the variance in naturalized streamflow. These long runoff records underscore the risks of relying solely on instrumental data to inform water resource policy, management practices, and planning. They also provide critical context for assessing uncertainty in the climate model projections used to force hydrological models for predicting hydrological drought. Research suggests that natural hydroclimatic variability, as recorded in radial tree growth, is the dominant source of uncertainty in the model projection of water balance variables.
