In addition, Hurricane Dennis passed by the study area before the pre-storm survey. Thus beaches were already eroded before Floyd, making it difficult for Floyd to remove more sand. The storm wave direction and shoreline orientation play important roles in beach erosion. The protruded areas facing hurricane onshore wind suffer more erosion than other areas. This results in remarkable spatial variations in net beach volume change per unit shoreline.
All beaches show net erosion.
Furthermore, the erosion magnitude display considerable spatial changes along and across the shore. In some cases the entire beach profile exhibits erosion. Yet in other cases the backshore erosion is coincident with foreshore accretion due to the movement of beach cusps or vice versa. The ALTM technology allows us to describe storm-induced beach changes in three dimensions with great detail. This technology demonstrates the ability to measure hurricane impact on coastal areas at spatial scales of tens of kilometers in less than one hour.