Appraisal of suspended sediment concentration on reference level according to van Rijn's method

Abstract

Appraisal of suspended sediment concentration on reference level according to van Rijn's method Appraisal of suspended sediment concentration on reference level according to van Rijn's method. The paper presents the results of sediment concentration measurements in the River Dłubnia at differentiated discharges of 0.44 m-3·s-1, 1.96 m-3·s-1 and 7.41 m-3·s-1. The elaborated concentration profiles based on hydrometric measurements permitted determination of Ca concentration on reference level "a" above the bed. The obtained reference concentrations were compared with the values obtained from calculations by use of van Rijn's formula. It was found that the calculated Ca concentration, applying the van Rijn's formula, is over five times higher than determined from concentration profiles. In order to obtain Ca concentration values, calculated by use of the empiric formula, approximate to real values coefficient correction must be determined. The elaborated preliminary estimation of the possibility of van Rijn's formula application for determination of this concentration on the reference level "a" above the bed showed that application of this method for appraisal of Ca concentration, by use van Rijn's formula, performed in the Dłubnia river of the catchment of the Upper Vistula river may be charged by errors. A faulty calculation of suspension sediment transport applying van Rijn's method may also point to it. Adoption of this method needs further verification and adaptation.