Simons et al. (1981) basic power function method
Kodoatie et al. (1999) expanded power function method
Yang (1996) sand and gravel equations
A summary of each method is given below to aid in selecting which method to use.
Meyer-Peter and Mller Bed Load Equation
The Meyer-Peter and Mller bed load equation only calculates the bed material moving in
contact with the bed (contact load). It does not give total bed-material discharge unless there
is no bed-material in suspension. It is, therefore, best utilized for coarser bed material
streams (D50 coarser than 2.00 mm).
Colby's Curves and Method
Colby's method is only for sand size bed material (D50 from 0.6 to 2.00 mm). It is very good
method for rapid determination of total bed-material discharge. It can be used to check or
compare with the other methods. The method can be used to determine the total bed-
material transport by size fraction.
Simons et al. (1981) Power Function Relationship
The Simons et al. power relationship can be used for steep streams with sand and fine
gravel-size bed material (D50 from 0.1 to 5.0 mm) that normally exhibit critical or supercritical
flow. The relationship takes into consideration the size distribution of the bed material (Table