Author(s): Randula Senarathbandara; Shawn Clark; Karen Dow; Kevin Lees
Linked Author(s): Shawn Clark
Keywords: River Ice; Advances in Ice Numerical Modelling
Abstract: Under cover ice transport processes play an important role in hanging dam formation and evolution during the freeze-up and ice-on periods. In the literature, a hanging dam is defined as a thick accumulation of frazil ice underneath an existing ice cover. Along with field and laboratory studies, numerical modeling is an effective way of investigating under cover ice transport processes and hanging dam formation under different hydraulic conditions. Comprehensive river ice simulation program (CRISSP2D) is a depth-averaged, two-dimensional numerical model that is capable of simulating various river ice processes. In this study, under cover ice transport processes in CRISSP2D were first evaluated in a rectangular ideal channel. Transport rates from the numerical modeling results which were based on Shen and Wang cover load transport formula were compared to the transport rates calculated from the Bagnold low density sediment transport formula. Model results were also compared to laboratory experiments conducted in a rectangular channel with a variable slope using simulated frazil ice and a simulated ice cover. The frazil ice deposition and erosion processes in CRISSP2D were then evaluated underneath an ice cover of the rectangular channel with a sudden drop in channel bed elevation. Under cover ice deposition in the numerical model was simulated using a range of hydraulic conditions. Depth-averaged velocity of the numerical model was compared to the under cover velocity measurements estimated from the laboratory experiments in the rectangular flume with a variable slope. This study is a preliminary step that will contribute towards assessing the existing numerical simulations of CRISSP2D model and comparing the model results to data obtained using laboratory experiments. This will provide an evaluation of the ability in the existing numerical simulations to predict the complex river ice processes.
Year: 2022