Nonlinear dynamics of tides and sandbars in tidal channels

Abstract

When tidal currents flow over the sandy bottom of a tidal channel, patterns emerge in the sand. These patterns grow into large tidal bars which are essential for plants and animals but hamper marine traffic. In this thesis we study the interaction between the tides and the bottom. The tides influence the transport of sediments and the patterns in the bottom influence the tides. First, we study the effect of tidal flats along a tidal channel on the characteristics of the tide in the channel. Subsequently, we analyze the initial formation of tidal bars. Hereby, we first solve an inconsistency in the literature about the question if the tidal bar length depends on the channel width. Secondly, we show the influence of the latitude of the channel to the initial formation of tidal bars. Lastly, we study by means of a numerical model how the initial bottom patterns evolve to matured tidal bars.