Bedload Predictions by Using the Concept of Particle Velocity: Applications

Abstract

Measurement of sediment transport is necessary to determine the amount of sediment load and to establish or check analytical or empirical sediment transport equations. These measurements differ in principle according to the mode of sediment transportation, i.e., bed load and suspended load, and the type of the transported sediment, i.e., clay, sand, and gravel. The focus of the proposed investigation is found on bed load transport (i.e., rolling, sliding, or bouncing) of gravel particles. Bed load is difficult to measure for several reasons. Any mechanical device placed in the vicinity of the bed will disturb the flow and hence the rate of bed-load movement. Moreover, it is very difficult to develop a device that accurately collects all the size fractions of the bed load. Finally, it is difficult to measure bed load rates in the field due to lack of access in some areas, especially at high flows, and lack of reliable measuring devices. The objective of this research is to employ an image analysis technique to monitor bedload motion in a laboratory flume under different flow and bed roughness conditions; and obtain unique information about the velocity of individual particles.