River discharges derived from single velocity measurements

[摘要] ENGLISH ABSTRACT:This work investigates methods to theoretically determine the lateral velocity distributionacross a river from which factors may be derived to translate a single point velocity intoaverage velocity for the river as a whole.A wide range of field data from vanous nvers was analysed. This produced over ahundred velocity distributions with which to compare theoretical distribution results. Fourtheoretical approaches were considered: the one-dimensional method (Manning'sequation), a two-dimensional flow formula solved as an initial-value-problem, a twodimensional flow formula solved as a boundary-value-problem and an empirical methoddeveloped from energy principles.The one-dimensional and initial-value-problem approaches were unsuccessful. Theboundary-value and empirical approach did however produce promising results.Surprisingly the analysis of the field data revealed patterns of similarity which couldproduce accurate results without the need of a theoretical approach.

[发布机构] Stellenbosch University