Effects of temperature and salinity on the suspended sand transport

Abstract

PurposeThe paper aims to present a study on the effects of temperature and salinity on the vertical distribution of suspended sand concentration and transport rate on the basis of 1DV model.Design/methodology/approachThe finite difference method based on the implicit scheme of Crank‐Nicolson with an irregular grid was used for the fluid flow equation and the implicit upwind scheme with a staggered grid for the equation of concentration diffusion. The model was applied to five tests of the data sets from the Delta Flume with three different cases of temperature and salinity on the basis of parameterisation of the kinematic viscosity, the turbulence‐related sediment mixing coefficient and the concentration at the reference level.FindingsThe computed results showed that the vertical distributions of suspended sand concentration depend on salinity and specially, on temperature. When temperature increases or salinity decreases, the settling process of particles occurs considerably faster. For fine sand, the discrepancy on suspended sand transport rates due to temperature or salinity decreases with wave height. For coarse sand, the effect of temperature and salinity is not much affected by the wave height.Originality/valueThe quantitative evaluation of the roles of salinity, especially temperature once again confirmed their importance for the sediment transport and the process of coastal morphology. The further sense from this research may suggest some new ideas on the tendency of evolution of sea bed due to the warming of the earth in the future.