A distinction between bed‐load and suspended load in natural streams

Abstract

Problems pertaining to the transportation of sediment by flowing water have been extensively studied by engineers and scientists during the last few years. Most of the various experiments have been concerned with either bed‐load or suspended load, but seldom have they been studied simultaneously. When bed‐load and suspended load occur simultaneously in a flume or stream a distinct difference in their mechanical composition is often observed. A curve fitted to the plotted data from a mechanical analysis of the bed‐material shows a distinct break. This break occurs most commonly in the data plotted from samples taken in mountain streams where the bed‐material is extremely coarse. For instance, in the Rhine River, Switzerland [see 5 of “References” at end of paper] the bed‐material ranges in size from pebbles 5 mm in diameter to boulders 100 mm in diameter and greater. Between boulders and in protected pools, however, sand one mm in diameter and finer is found, whereas particles ranging in size from one to five mm are not present. The explanation for this size‐distribution has been that the material greater than five mm in diameter moves as bed‐load and the material finer than one mm in diameter moves as suspended load. Particles ranging in size from one ram to five mm in diameter occur rarely for certain geologic or hydraulic reasons [3].

Modes of sediment transport in channelized water flows with ramifications to the erosion of the Martian outflow channels

“…The analysis of the wash load has proved difficult in that, unlike the bed and suspended loads, the concentration and total transport rate of the wash load do not always relate to the river-flow parameters (t~, u., discharge or flow power) (Einstein et a/., 1940: Colby, 1963: Guy, 1964. Instead, (7) the concentration depends more upon the geology of the river's drainage basin and upon the climate.…”

Assessment of spatiotemporal variations in the fluvial wash-load component in the 21st century with regard to GCM climate change scenarios

“…bed load, suspended load, wash load) and a bed function and wash load, which are independent of riverbed variation. This is a fundamental concept in the derivation of all theoretical sediment transport formulae (Einstein et al, 1940;Einstein, 1950;Bagnold, 1966Bagnold, , 1973Bagnold, , 1977Ashida and Michiue, 1972;Ackers and White, 1973;Kiat et al, 2008;Konrad, 2009;Rajaee, 2011;Xue et al, 2012;Haddadchi et al, 2013). Bed material load comprises both bed load and suspended load, which consist of grain sizes represented in the bed, and moves downstream either as bed load or as suspended material that is constantly exchanging with the bed.…”

Estimation of the Amount of Suspended Sediment in the Tigris River using Artificial Neural Networks

“…A total number of 329 data records are used in the study including monthly average rainfalls [mm], air temperature [8C], discharge [m 3 /s] and suspended-sediment [tons/year]. The first 165 of these data records are used to determine the weights of the models (training stage) and the remaining 164 are exploited for testing the models.…”

“…Since 1940, there have been a few studies including that of Einstein et al [3] for the Enoree River and Nordin and Dempster [4] for the Rio Grande, which express the view that rainfall and initial flow have a major effect on sediment load changes. Data obtained from seven rivers in the United States of America Atlantic region were analyzed, and it was found that the sediment loads are due to flow discharge, peak flow, amount of rainfall and its frequency [5].…”