Hydrodynamics Under Storm Conditions
Résumé
Storms usually induce a surge that causes the water level to reach a higher position
compared to normal conditions. In addition, wave energy is usually higher than normal
under storm conditions so that currents and subsequent sediment transport can
induce dramatic morphological changes, including severe erosion. This chapter aims
to present the main processes that control water level variations and hydrodynamic
circulation under storm conditions. The section following this introduction presents the
main mechanisms that control storm surges: atmospheric pressure gradients, surface
stress and short-wave dissipation. The third section presents the mechanisms that
drive the hydronamic circulation along the coast: longshore currents, bed return flows,
infragravity waves and swash dynamics. This chapter concludes with some perspectives
and challenges.