Error Estimate in Einstein's Suspended Sediment Load Method

Abstract

Computation of suspended sediment load in open channels relies on the integration of the product of the suspended sediment concentrations and the fluid velocity profile. Sediment in the flow, however, travels at a lower velocity than the fluid. Errors due to the relative velocity between sediment particles and fluid are evaluated based on experimental data. The procedure for calculating the errors in Einstein's method does not involve calculating the actual suspended load; instead, it relies on determining the relative error between the loads by using both the fluid velocity profile and the sediment velocity profile. Although there is an abundance of data on the velocity profiles in open channel flows, with and without sediment in the flow, data on sediment velocity profiles is scarce. The analysis of the available data indicates that Einstein's method for computing the suspended sediment load overestimates the load by about 40, in some cases. Further data collection and subsequent analysis is needed to more accurately formulate the difference in sediment loads based on Einstein's method.