Author(s): Manzoor A. Ahanger; Girdhari L. Asawa; Mohd A. Lone
Keywords: Dimensional analysis; hysteresis; sediment rating curve; suspended load; tilting flume; unsteady flow
Abstract: The tendency for sediment concentration to have different values at identical stream discharges of the rising and the falling stages of a flood hydrograph is termed as hysteresis effect. Herein experiments were carried out on a tilting flume using two uniform sizes of sand, of diameters 0.3mmand 0.35 mm. Fourteen flow hydrographs were used, and the suspended sediment concentrations at different intervals of time measured to find out the sediment discharge. Using the technique of dimensional analysis the variables affecting the sediment transport phenomenon were grouped into four dimensionless parameters. Two separate equations, involving the four dimensionless parameters, were obtained, for the rising and falling stages, using regression analysis. The resulting values of the suspended sediment discharge obtained from these equations were validated on a fresh set of hydrographs, and found to be in good agreement with the observations.