A model of the transport of the sediments suspended by a tidal flow in the coastal zone of the sea

The aim of this study is to develop methods for predicting the vertical distribution of the discharge, concentration, and statistical characteristics of sandy and silty sediments suspended by a tidal flow averaged over intervals significantly smaller than the tidal period. We consider the sediments suspended from a bottom that is assumed to be erodible with the possible formation of ripples. The solution obtained represents a second order model with respect to that proposed by the authors earlier, where some problems posed were solved with averaging intervals that are multiples of the tidal period. Theoretical and laboratory studies of a steady flow with suspension are used to develop the solution. The concentration field of heterogeneous sediment is considered as a sum of the fields of individual homogeneous groups of particles (fractions) moving under common regulations. The tidal flow is represented by a series of consecutive steady states (steps). The solution developed was verified by the measurements in Bahia Blanca Bay in the West Atlantic. The mass of the particles that should be caught by sediment traps was calculated by the model and compared with the measured values for each fraction. The comparison results seem to be quite satisfactory.