The development of the mechanics of transportation
of sediment by fluids has been carried on mainly in
connection with the control and development of
streams where its greatest economic importance lies.
The difficulties of controlling rivers are concerned
largely with such matters as the ability of the flow
to erode the banks and bed or the possibility of aggradation due to insufficient transporting capacity. Thus, stream control problems are to a great extent
problems in sediment transportation. Although sediment
transportation is closely identified with
streams, its application is by no means limited to
this field. It is of importance in many industrial
processes where solids are transported by liquids or
gases or where solids need to be mixed and/or separated
from fluids, and in the important field of
transportation of soil by wind.
In this paper a brief outline will be given of the
mechanics underlying this subject. No attempt will
be made to discuss the many important practical
problems which provided the incentive for developing
this special branch of fluid mechanics