The winter regime of river-ice covers in high northern latitude regions is often a
determining factor in the management of water resources, conservation of aquatic ecosystems
and preservation of traditional and cultural lifestyles of local peoples. As ground-based
monitoring of river-ice regimes in high northern latitudes is expensive and restricted to a few
locations due to limited accessibility to most places along rivers from shorelines, remote
sensing techniques are a suitable approach for monitoring. This study developed a
RADARSAT-2 based method to monitor the spatio-temporal variation of ice covers, as well
as ice types during the freeze-up period, along the main channel of the Slave River Delta in
the Northwest Territories of Canada. The spatio-temporal variation of ice covers along the
river was analyzed using the backscatter-based coefficient of variation (CV) in the 2013–2014
and 2014–2015 winters. As a consequence of weather and flow conditions, the ice cover in
the 2013–2014 winter had the higher variation than the 2014–2015 winter, particularly in the
potential areas of flooded/cracked ice covers. The river sections near active channels (e.g.,
Middle Channel and Nagle Channel), Big Eddy, and Great Slave Lake also yielded higher
intra-annual variation of ice cover characteristics during the winters. With the inclusion of
backscatter and texture analysis from RADARSAT-2 data, four water and ice cover classes
consisting of open water, thermal ice, juxtaposed ice, and consolidated ice, were discriminated
in the images acquired between November and March in both the studied winters. In addition
to river geomorphology and climatic conditions such as river width, sinuosity or air temperature,
the fluctuation of water flows during the winter has a significant impact on the variation ofice cover as well as the formation of different ice types in the Slave River. The RADARSAT-2
based monitoring algorithm can also be applied to other river systems in high latitude
ecosystems to annually monitor their river-ice variation and formation during the freeze-up
and ice cover progression period.