where Vwc is the depth averaged velocity determined from the above described 

 modification to the current velocity to account for the effect of waves (ft/sec), d is the 

 mean depth of flow (ft), and v* is the shear velocity (ft/sec) which can be defined from 

 Chow (1959, p 204) as: 



V. = 



yfgV^ 



(13) 



where Cz is the Chezy coefficient. 



The third nondimensional parameter, Ggr, defines a sediment transport rate as a 

 ratio of shear forces to die immersed weight multiplied by the efficiency of transport. The 

 efficiency term is based on work needed to move the material per unit time and the total 

 fluid power. The transport rate is written as 



G = — 



'' sD 



^v. ^ 



(14) 



where X is a nondimensional sedunent transport function in the form of mass flux per 

 unit mass flow rate. The sediment transport rate Ggr can be related to the mobility 

 function Fgr through the following relationship: 



G„=C 





(15) 



Equations 14 and 15 are used to solve for X as: 



X=C 



(F. 



^-1.0 



d 



^V... ^" 



v^*; 



(16) 



A dimensional sediment load transport rate Qb, defined in cubic feet of sediment 

 (solids) per second per unit width can be written as: 



A Predictive Model for Sediment Transport at the Portland Disposal Site, Maine 



