The measurement of sand transport by the time-integration method with radioactive tracers

Abstract

A method of measuring the transport of sand in a laboratory flume is described in which a small quantity of radioactive sand is introduced into the flow. The method is similar in principle to the time-integration method used for measuring the discharge of liquids. The mean velocity of the sand particles can be deduced directly from the measurements. The volume rate of transport can be inferred either by an independent measurement of the thickness of movement of the bed ripples, or by mixing the active sand uniformly with a strip of the bed at the start and measuring the loss of active sand during the experiment. An adequate length must be left between the point of injection and the section at which the passage of tracer is measured. This length depends on the hop lengths of the particles and not on the frequency with which hops are performed.