A study in the estimation and measurement of bed load discharge

Abstract

The subject of the thesis is the estimation and measurement of bed load discharge, i.e. the rate at which coarse sediment particles are transported in a flow of water, in particular in the River Tyne near Bywell. The first part of the thesis deals with the estimation of bed load discharge using empirical or theoretical formulae. A description of the collection of the necessary hydraulic and sediment data for the Bywell reach is followed by an account of the determination of the relationship between bed load discharge and river stage by several of the formulae available at present. Estimates of the average annual bed load discharge in the River Tyne at Dywell are given. In the second part of the thesis, concerning the direct measurement of bed load discharge, attempts to use a trap-type sampler from the Bywell cableway are described. An account of the development of an experimental laboratory channel for the investigation of an alternative technique, the detection of sediment movement by acoustic methods, is followed by a comparison of the observed and theoretical relationships between bed load discharge and the sound emitted by inter-particle collision of the moving sediment. An acoustic bed load detector for rivers is also described. Finally, a summary of concluSions, including recommendations for further research, is given.