Abstract
The patterns of grain-size distribution of point-bar sediments on the Usri River, India, were compared to log-normal, log-hyperbolic, and log-skew-Laplace distribution models. Sediment samples were collected from a specific size of bedform ranging in foreset thickness from 23 to 40 cm, from the source to the mouth of the river over a distance of about 90 km. The hydrodynamic parameters of the river were also measured at four point-bars.
The results indicate that (a) the log-normal distribution is the best fitted distribution model among the three distribution models, (b) after a certain distance of transport, the log-normal distribution becomes log-hyperbolic, and (c) though there is a tendency for grain size to decrease downstream within each point bar, together with improvement of sorting, this pattern is not consistent along the entire course of the Usri River from one equivalent bar position to the next, or from the source to its mouth.