Sediment transport by laminar and turbulent flow are phenomena involved in the natural environment and industrial processes. In this book we present a study of sediment transport in the creeping and saltation regimes by laminar and turbulent flows. In our model the particles are supposed as hard disks in a two-dimensional domain with periodic boundary conditions in the horizontal direction. The motion of particles is calculated by the event driven molecular dynamics method. The fluid that is modeled by its velocity profile, flows over the bed, so the particles can be entrained by the fluid...