1. A short section of artificial channel constructed in a river in order to create a constriction in which critical flow will be established, allowing the discharge to be calculated from the water depth.

2. An experimental channel used for studying relationships between sediment movement and flow conditions. There are a number of different flume designs but most flumes are capable of carrying water at variable depths and velocities, either in a unidirectional flow or generating waves. Flume studies have been responsible for establishing the important relationships between the grain size (see particle size) and erosion velocities and stability fields for the various sediment bedforms.