  An experimental device has been built to measure velocity profiles and
friction laws in channeled snow flows. The measurements show that the velocity
depends linearly on the vertical position in the flow and that the friction
coefficient is a first-order polynomial in velocity (u) and thickness (h) of
the flow. In all flows, oscillations on the surface of the flow were observed
throughout the channel and measured at the location of the probes. The
experimental results are confronted with a shallow water approach. Using a
Saint-Venant modeling, we show that the flow is effectively uniform in the
streamwise direction at the measurement location. We show that the surface
oscillations produced by the Archimedes's screw at the top of the channel
persist throughout the whole length of the channel and are the source of the
measured oscillations. This last result provides good validation of the
description of such channeled snow flows by a Saint-Venant modeling.
