Use Equation 4.19:

3/2

3/2

D90

1/ 6

Q

qB = 4.780 10.846 b

y o S f - 0.627 Dm

Q

n

b

From Equation 4.21:

2/3

5.98 .06

3/2

1 -

nb = (.04) 1 +

= 0.038

60.96 .04

From Equation 4.23:

Qb

1

= 0.84

=

1.5

Q

5.98 0.06

1+

60.96 0.038

3/2

3/2

2.8

1/ 6

(2.99) (.0005) - 0.627 (2.01)

qB = 4.780 10.846 (0.84)

0.038

qB = 5.65 metric-tons/day/m

Qs = 5.65 x 60.96 = 344 metric-tons/day

The application of the Einstein method to calculate total bed material discharge is given in

English units only. See Example Problem 4.13.4. The example is taken from Einstein's

1950 publication.

The application of Colby method to calculate total bed-material discharge is given in English

units only. See Example Problem 4.13.5. The example problem uses the hydraulic and

sediment data given by Einstein for the purpose of comparison of the two methods.

The Colby method is easy to use. Organizations using SI units are encouraged to convert the

input variables to English units, solve the problem, and convert the results back to SI units.

4.39

Integrated Publishing, Inc. |