The effect of sediment characteristics in littoral transport evaluation

Abstract

Numerical models are commonly used in coastal engineering studies to evaluate sediment transport along the coastline and to predict beach morphological evolution. Their application requires the knowledge of physical characteristics of sediments that, due to the cost and time involved in sampling and laboratory analysis, are often taken from literature instead of evaluated from in situ data. The variability of these input physical parameters can determinate the accuracy of sediment transport evaluations. In order to assess the uncertainty of drift numerical evaluation, sensitivity analyses of longshore sediment transport to grain size distribution and density were performed. Results show that it is particularly important to correctly specify the median diameter when simulating fine sediments dynamics. Moreover, for this grain size range, the variability in spreading and density can have an important impact in the longshore sediment results, with maximum errors of 80%.