Effects of River Geomorphology on River Ice Freeze-up and Break-up Rates Using MODIS Imagery

Evaluating driving factors of river ice freeze-up and break-up is critical for the understanding associated with river ice processes, as well as for providing a means to predict potential natural hazards of river ice formation or deformation. Spatiotemporal changes from fifteen years (2000-2015) of MODIS reflectance band 2 images were analyzed in pixel-wise linear regressions to be used as an indicator of the rates of ice freeze-up and break-up along the Slave River (Canada). The random forest algorithm was used to model the rates using river corridor slope, effective width, shape, and sinuosity as a set of predictor variables. The results reveal that the selected predictor variables can explain about 80% and 70% of the variations in ice freeze-up and break-up rates along the Slave River respectively. The slope was the most important factor in determining both freeze-up and break-up rates, followed by shape, effective width, and sinuosity. The spatiotemporal patterns of river freeze-up and ice-cover break-up obtained from the analysis of MODIS data and geomorphological variables show strong agreement with ground observations and hydrometeorological conditions along the Slave River.