NONLINEAR MODELING OF TIDAL SANDBANKS: WAVELENGTH EVOLUTION AND SAND EXTRACTION

摘要

A process-based morphodynamic model is developed to investigate the nonlinear dynamics of tidal sandbanks. We focus on two types of dynamics: autonomous behaviour of a patch of sandbanks and the response of such a system to a local removal of sand. Simulations for asymmetric tidal conditions indicate that sandbanks gradually attain a larger wavelength than suggested by existing linear stability models. Sandbanks are found to recover from sand extraction. We discuss the time scales associated with these processes as well as the implications for our understanding of sandbank dynamics.