Wave-current interaction on morphological evolution of rip channel systems

Abstract

Current effect on waves (CEW) is examined for formation of rip channel systems with a barotropic model that consists of an Eulerian phase-averaged shallow water equation with a vortex-force formalism, WKB ray equations, and a bed evolution equation with the Soulsby-Van Rijn's total sediment flux formula. CEW acts on reducing the offshore extent of seaward rip currents through wave refraction on the currents, leading to modifying the budget of sediment flux and the associated surf-zone topography. Inclusion of CEW results in shoaling rip channels, deepening offshore mounds, and elongating alongshore spacing of rip channels with both the normal and oblique incidence of offshore waves.