Measurement of hydraulic and sediment transport variables in a small recirculating flume

An evaluation of techniques for measuring the hydraulic and sediment transport variables in a small recirculating flume showed that (1) the average depth of flow over a ripple bed could be determined adequately by measuring the difference between the water‐surface elevation and the sand‐bed elevation at a large number of positions and averaging the results; (2) the water‐surface slope could be determined easily and accurately from a series of piezometers with taps positioned at 1‐meter intervals along the flume center line; (3) the sediment transport rate was determined by passing all the water‐sediment mixture through a trap covered with screen fine enough to hold the sand. The transport rate varied considerably (10‐fold range) with respect to time. The following transport phenomena were noted: (1) there was no particle movement on the plane bed before ripple formation; (2) the mean velocity for cessation of particle movement (on the ripple bed) was about one‐half that at which first movement occurred (on the plane sand bed).