INFLUENCE OF DEVELOPMENTAL CONDITION OF SAND SPIT ON INTRUSION CHARACTERISTICS OF WAVES INTO AN ESTUARY

Abstract

 In this paper, the authors conducted numerical analyses of wave propagation in order to clarify the influence of the developmental condition of a sand spit on intrusion characteristics of waves into an estuary. In the numerical analyses, the opening position of river mouth, the flow depth around the opening, and the opening width were changed systematically, and the NOWT-PARI which is based on a Boussinesq equation was applied. Consequently, our analysis results showed a possibility that the wave intrusion into the deep part of the estuary is reduced because the waves entering from the opening propagates to the opposite side of the opening depending on the hydraulic conditions. Moreover, the analysis results pointed out that the cause which the waves entering from the opening deflected in the opposite direction might be the influence by the large-scale vortex formed in the estuary due to the inflow from the opening.