Numerical modelling of sediment transport in an ice covered river.

Ahmad Shakibaeinia, Shalini Kashyap, Yonas Dibike, Terry Prowse, Ian Droppo

Thursday 2 july 2015

8:30 - 8:45h at Mississippi (level 1)

Themes: (T) Sediment management and morphodynamics, (ST) Sediment transport mechanisms and modelling

Parallel session: 10A. Sediment - Transport

The transport of sediment and the associated chemical constituents originating from potential anthropogenic and natural sources are becoming an issue of increasing importance in the lower reaches of the Athabasca River ecosystem in northern Alberta, Canada. As a cold region river, the annual cycle of ice cover formation and breakup play a key role in sediment transport in this river. This numerical modelling study investigates the transport of fine cohesive sediments in the lower Athabasca River during both ice-covered and open-water periods. A one-dimensional (1D) river ice model is used to predict the ice coverage and its effect on the flow characteristics. The results of the ice model are used to investigate the effect of ice-cover on the sediment erosion, deposition and transport pattern within a ~200 km reach of the lower Athabasca River. A two-dimensional (2D) hydrodynamic/sediment transport model is also applied for more detailed simulations of lateral variations in specific regions. Results are validated and evaluated using available field measurements. Model output is discussed in relation to their utility for understanding and assessing the implication of the sediment dynamics on chemical contaminant fate. Furthermore, results help to obtain a better understanding of the important effects of ice-cover on sediment transport in cold region rivers.