Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Civil Engineering

First Advisor

Alan Prasuhn


A major concern confronting hydraulic engineers is the ongoing problem of predicting and controlling sediment transport in unlined water carrying channels. The sediment load in a stream is not only indicative of channel and land erosion but also affects water quality, navigation and the useful life of a reservoir. A number of methods have been developed which compute sediment load. All of these methods depend on a number of sediment properties, the most significant being sediment size, sediment specific gravity and fall velocity. Fall velocity is considered by many to be the most fundamental of these properties. Fall velocity, which may be defined as the velocity at which a sediment particle falls through a fluid, is important for a number of reasons. It is an indicator of a particle's size and weight since the larger and heavier a particle is, the faster it falls through a fluid. In the same manner, it reflects the fluid's characteristics. Fall velocity is also useful for calculating retention times in settling basins and predicting the location of sediment deposits in a reservoir. It has also been determined that the fall velocity of a particle is directly related to the stream velocity required to move particles along a stream bed. The most important application of fall velocity is its use in the previously mentioned formulae for computing sediment transport load. This report further examines the concept of fall velocity and presents a computer program for the calculation of fall velocities which meets the following criteria: 1. The results must be accurate for a wide range of particle shapes, particle specific gravities and fluid temperatures and specific weights. 2. The method of solution must be simple and direct.

Library of Congress Subject Headings

Sediment transport -- Computer programs
Sediments (Geology)



Number of Pages



South Dakota State University


No Copyright - United State