Flow and sediment transport measurements in a simulated ice-covered channel

Laboratory flume experiments conducted to illuminate flow field and sedimen t transport characteristics in ice-covered sand-bed channels are discussed. The overall purpose of the experiments was to examine how level ice covers affect flow distribution, flow turbulence characteristics, and sediment tr ansport rates. The experiments were conducted with a nonrefrigerated flume fitted with a sand bed and plywood panels used to simulate cover-floating i ce covers. A discriminator laser-doppler velocimeter was used to measure wa ter and sediment particle velocities simultaneously. The addition of a cove r and an increase in its roughness increases flow depth and decreases bulk flow velocity thereby reducing sediment transport rates compared to those i n open water flow. The Reynolds shear stress, turbulence intensities, and d istribution of sediment size over the depth also change.