Ice cover influence on transverse bed slopes in a curved alluvial channel

Abstract

Abstract Presented are the results of a study to determine the influences of level ice cover presence on bathymetry, particularly transverse bed slopes, of a curved alluvial-bed channel. The study, which is of significance for under-standing flow in ice-coverred rivers, entailed conduct of a laboratory experiment using a curved a flume and adaptation, to cover-flow conditions, of prior formulation of openwater bend flow. The formulation treats bend flows as a damped, forced oscillatory system for which changing channel alignment prescribes a forcing function, and transverse bed slope is a depent variable of fluctuating magnitude. It was found that cover presences alter flow distribution, mildly diminishes transverse bed slopes, but more significantly diminishes bedload transport of sediment. Increased roughness of cover underside, water temperature, additionally reduce transverse bed slopes.