determine the average annual sediment discharge. To determine the average annual total
bed-material discharge the computer model is used to determine the bed-material discharge
for a range of discharges to develop a sediment discharge rating curve or table. This rating
curve is used in combination with a flow duration curve or table to determine the average
annual bed-material discharge. BRI-STARS can be used for single event or long-term
sediment transport simulations, whereas HEC-6 is better suited for long-term simulations and
should be used with caution for single event simulations.
The U.S. Army Corps of Engineers SAM package (Thomas et al. 2000) includes sediment
transport calculations using a wide variety of equations. The SAM package uses normal
depth hydraulics and does not perform sediment routing. It is intended for basic sediment
transport analysis and for developing sediment rating curves as part of a sediment yield
analysis.
4.12 SOLVED PROBLEMS FOR SEDIMENT TRANSPORT (SI)
4.12.1 Introduction
The following example problems illustrate the application of concepts and equations for
sediment transport. Because several of the equations are commonly given in English units
(for example Einstein's equation) and the methodology is very complex, some of the
examples will only be given in English units. Readers who use metric units (SI) are
encouraged when encountering similar problems to convert the input variables to English
units, solve the problem, and convert the results back to SI units.
4.12.2 Problem 1 Suspended Sediment Concentration Profile
From data observed on the Missouri River, calculate the vertical suspended sediment
concentration profile for the D50 sediment size in mg/l.
Given:
y o = 4.30 m
V = 1.27 m / s
S = 0.000210
Temp = 22.5C (72.5F)
D50 = 0.000255 m
ω (D 50 ) = 0.0338 m / s
υ = 1.00 x 10 -6 m2 / s
c a = 775,000 mg / l
From Equation 4.12:
Z
y - y
a
ω
c
= o
and z =
yo - a
βκV*
ca y
4.37
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