Sand bar behavior: Observations and modelin

The relation between the number of sand bars in the nearshore zone and the forcing wave conditions was evaluated using observations and numerical modeling at Walton and Volusia Counties, in the State of Florida. The decadal behavior of the number of bars was well represented using a simple quantitative model that correlates the wave forcing and number of bars. The Dean and Profile non-dimensional parameters, used to determine the number of bars in equilibrium with the wave forcing, presented the best correlation between model and observations, indicating that wave and sediment characteristics are important to predict the number of bars in the nearshore zone. The model succeeded in representing the rapid increase in the number of bars during major storms or hurricanes and the slower decrease in number of bars during calm periods.;The breakpoint theory used in the short term model captured the relationship between the inner and outer bars, where the outer bar tends to be more linear, since only high waves are able to effectively transport sediments into greater depths. The inner bar morphology is more three dimensional where alongshore differences are more evident. The offshore migration or increase in the outer bar depth was observed to be the trigger for the inner bar formation. The short term model represented the number of sand bars when the surveys were conducted close to periods of high energy when the sand bars were formed or migrated to the position and depth according to the wave forcing that generated the system with multiple bars. It was also observed that the inner and outer bars are interconnected systems with multiple bars and the study of this system has to be conducted including all bars at the same time.