Numerical Simulation of Morphological Changes of Tidal Estuary Under the Effects of Tides and Waves perpendicular to the Shore

Inlets play an important role in controlling sediment movement and its distribution in coastal areas. Therefore، recognizing effective factors in the hydro-dynamicity of inlets known as transmission process and determining the geometry and formation of inlets are of paramount importance. The undulations of water and tidal waves are among the major factors shaping an inlet. The purpose of this study is to find out how these two factors could interactively affect the sediment. To this end، a coastal basin that is connected to the open sea through a mouth is simulated in Mike 21/3 software. For this simulation، a 10*50 meter un-structured triangular flexible mesh in a finite difference model at two seconds intervals was used; undulations and tidal waves were sent to the mouth of the inlet simultaneously. By simulation، the morphology of the inlet changes in a way that with the passage of time reaches equilibrium; hence، there would be an ideal inlet. Also، by means of characteristic non-dimensionalHw/Ht، the dominant parameter in the inlet can be determined in the inlet. For calculation of morphological changes in inlet of estuary، first tidal fluctuations as a single parameter and then wave parameter separately considered، then two parameters together considered، the results show that for two cases، the morphological changes are the same