Parameters - relative density of sediment

The relative density of the bed material, s, is defined as the ratio of the sedi­ment density, r_s, to that of water, r.

When setting the value of s it is important to keep in mind that the transport formulations used by MIKE 21 ST have been developed for normal sand. MIKE 21 ST will yield results for light materials (s smaller than 2.50) and heavy sediments (s larger than 2.70), but care should be exercised in the interpretation of these results