With MIKE 21C, each sediment fraction can have its own sediment transport modes and specified formulas. Cohesive sediment fractions are handled as suspended load with traditional erosion and deposition functions, while non-cohesive sediment fractions can have bed-load and suspended load set individually. Several non-cohesive sediment transport formulas are also available including: Engelund-Hansen, van Rijn, Engelund-Fredsøe, Meyer-Peter & Müller, Smart-Jaeggi, Yang, Wilcock & Crowe, Garcia & Parker, Parker, Ackers & White and Lane-Kalinske.
Bed-load is always considered in equilibrium and includes the effect of helical flow and bed slope.
All suspended sediment transport, including cohesive and non-cohesive sediment fractions, are also uniquely handled with Advection-Dispersion (AD) equations. These are specific for each fraction due to the individual convective fluxes associated with helical flow and non-uniform concentration profiles, as well as specific dispersion coefficients. The AD equations are solved using an implicit scheme.