Modelling of sediments and morphological processes have traditionally been separated by the material characteristics such that non-cohesive sediments (sand) have been treated differently from cohesive sediments (mud).

Modelling of purely non-cohesive sediments imply an assessment of the sediment transport rates and initial rates of bed level change resulting from currents or combined wave-current flows whereas modelling of fine sediments is focussed on describing the erosion, transport and deposition of cohesive and cohesive/granular sediment mixtures under the action of currents and waves.

For detailed studies of the transport and fate of dissolved and suspended substances discharged or spilled within the water column it is possible to adopt a Lagrangian modelling approach where the particles are tracked individually.

The classic modelling approach is inherented in the sediment modules in MIKE 21 and MIKE 3 which both includes a cohesive (ST) and non-cohesive (MT) sediment module as well as a Lagrangian sediment module (PA).

Often coastaline kinetics and littoral processes can be described well and adequately using a 1D approach. In such cases the LITPACK software package is superior and very efficient.