Table B.4. Summary of Applicability of Selected Sediment Transport Relations

(Kodoatie et al. 1999).

Med Very

Very Fine to

Small

Intermed

Large

Method

Gravel

Coarse Sand

Fine Sand

Silt

Rivers

Rivers

Rivers

1

Ackers and White

X

X

2

Bagnold

X

X

X

X

3

Brownlie

X

X

X

X

4

Einstein

X

X

5

Karim

X

X

X

6

Karim and Kennedy

X

X

X

7

Laursen

X

X

X

X

8

Shen and Hung

X

X

X

9

Toffaletti

X

X

X

X

10

Yang '73 and `84

X

X

X

Power relationships empirically relate sediment transport with hydraulic conditions and

sediment characteristics. They can be developed by fitting the coefficients to computed

sediment transport from more sophisticated equations or to measured data. Their utility is in

their ease of use and, when developed from measured data, their site-specific accuracy.

In 1981, Simons et al. proposed an efficient method of evaluating sediment discharge. The

method is based on variables flow depth, velocity, and particle diameter, and gradation

coefficient. It can be easily applied in steep sand and fine gravel-bed creeks and rivers that

normally exhibit critical or supercritical flow. It will also be shown that a modification of this

relationship can be applied to subcritical rivers. This is the only transport relationship

specifically developed for upper flow regime conditions. These power relationships were

developed by Simons et al., from a computer solution of the Meyer-Peter and Mller bed load

transport equation and the integration of the Einstein method for suspended bed sediment

discharge (Julien 1995) and expressed as

qs = c s1y cs2 V cs3

(B.3)

where:

= Unit sediment transport rate ft2/s (m2/s)

qs

cs2, cs3

fine gravel

= Coefficient based on mean particle diameter (note that Cs1

cs1

must be adjusted for SI units - see Section 4.8.2)

y

= Mean flow depth, ft (m)

V

= Mean velocity, ft/s (m/s)

B.15

Integrated Publishing, Inc. |