Janowicz, J. R.
Increasing winter baseflow conditions apparent in permafrost regions of Northwest Canada
// 16th international symposium and workshop "Northern research Basins". Petrozavodsk: KarRC RAS, 2007. Pp. 51-56
Keywords: Continuous, discontinuous, sporadic permafrost, 7-day low flow, trend analysis, Mann-Kendall
Yukon air temperature trends have been observed to change over the last several decades. Summer and winter air temperatures have increased in most regions except southeastern Yukon. The greatest changes have occurred in western, mountainous regions where both summer and winter temperatures have increased significantly. Hydrologic response was generally found to be characterized with higher year round flows. Mountainous streams were found to have the timing of the freshet advanced, with a progressive decrease in this peak flows moving from south to north. An assessment of winter low flow conditions was carried out to determine if recent changes were apparent in response to the observed temperature changes. Winter low flows are represented by the mean 7 day low flow. Winter low flows have experienced apparent changes over the last three decades. The greatest changes in winter streamflow appear to be occurring within the continuous permafrost zone, where flows from the majority of sampled streams have increased. Winter low flows trends in streams within the discontinuous permafrost zone generally exhibit positive trends, but are more variable. Winter streamflow trends within the sporadic permafrost zone are not consistent. Increasing winter streamflow trends have occurred from some mountainous regions of alpine permafrost. Other streams exhibit no discernable change, while one stream exhibits a negative change.