Finite elements method based on Galerkin’s formulation for predicting the sand bars position

Abstract

The accurate knowledge of the location and movement of the sand bars is important for the coastal manager to establish correctly the coastal defence elements. This work applies a numerical model of finite elements based on Galerkin's formulation for predicting the location of the start, crest and end of the outer bar. The model that shows the best results is the one that combines the variables wave height, period and median sediment size. The mean errors are less than 10 m in the distance to the shoreline and 17 cm in the depth, while in the formulations proposed by other authors the errors are more than 100 m in the distance to the shoreline and 2 m in the depth. Thus, the proposed model significantly improves the calculation of the sand bars position. This will allow a better location of the coastal defence elements, and therefore an improvement in their effectiveness and optimisation of the materials to be used in their construction, the key to sustainable coastal management. Furthermore, although the model was developed for the area of Valencia (Spain), the model can be used in any area with similar characteristics (open sandy beach), and the methodology (variables and process) could be applied worldwide.