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Technical Service Center
Sedimentation and River Hydraulics Group

BORAMEP: Bureau of Reclamation Automated Modified Einstein Procedure

Developing a reliable and consistent method of computing total sediment discharge within a river is one of the most important practical objectives of research in fluvial processes (Burkham and Dawdy, 1980). Current techniques for suspended sediment collection do not allow sampling throughout the entire depth of flow and therefore the concentration and particle size distribution in only part of the flow can be determined from the suspended-sediment samples. The unsampled flow near the stream bed normally contains higher concentrations and coarser particle-size distributions than the flow in the sampled zone. Thus, the concentration of suspended-sediment samples is usually lower than the suspended-sediment concentration for the entire depth, and the particle sizes of the samples are usually smaller that the particle sizes for the entire depth.

In 1950, Einstein presented a procedure for computing the total discharge of sediment of sizes found in appreciable quantities in the stream bed for a long reach of a stream channel. However, acquiring the data required by Einstein’s procedure was very labor intensive and time consuming. In 1955, Colby and Hembree presented a modified version of Einstein’s procedure (MEP) that used data from a single cross section to calculate the total sediment discharge for a particular reach. The MEP is considered an improvement over the original Einstein method because it is simpler in computation and it uses parameters more readily available from actual stream measurements. The modified method, however, requires a great deal of experience and judgment to obtain reliable results and often times the results are not easily replicated by multiple users. Computations are made for several ranges of particle sizes and involve many variables resulting in a very complex process of computing total sediment load. As a result, a more simplified and automated method of computing total sediment discharge for a given reach that can be reproduced by numerous users is of great interest.

The primary objective of this program was to present a reliable and readily automated algorithm for computing total sediment load using Reclamations version of the MEP procedure as described in Reclamations 1955 and 1966 publications. The algorithm has been developed and deployed through a computer program that is applicable to a wide range of flow and sediment conditions and provides information to identify areas where additional research might be needed.

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Contact David Raff, (303) 445-2461, for more information on the BORAMEP program.