River Sediment Transport and Deposition Modeling

Abstract

Sediment can be transported in several ways by the action of a river. During low transport stages, particles move by sliding and rolling over the surface of the bed. With the increase of the velocity, the sediment is entrained into suspension and travels significant distances before being deposed again. One can observe a continuous exchange between sediment at the river bed and sediment in suspension. Moreover, when the concentration of suspended sediment is elevated, the river can plunge into the ocean creating an hyperpycnal plume.All this phenomena may be modeled by means of a coupled model constituted by a hydrodynamical component, described by a Shallow water system and transport equations for sediment in suspension with erosion and deposition source terms, and a morphodynamical component, which depends on a bedload transport flux.The mathematical model proposed allows to model the phenomena previously described as well as pure bedload or suspension transport and hyperpycnal plumes.The equations are solved using path‐conservative schemes described by Parés et al..