Modelling of the initiation and development of tidal creek networks

Abstract

The physical and numerical modelling of the initiation and development process of tidal creek network in tidal environments is presented herein. An attempt was made to reproduce the developing process of tidal creeks on a small experimental flume by considering the scaling rules of flow and sediment transport associated with tidal flows between the real scale and an experimental flume. In the experiments, the initial stage of channel evolution and the complex channel network configuration were successfully modelled, and results show that the similar network geometry observed in tidal environments can be reproduced at an experimental scale. Numerical simulations of initiation and development of tidal creeks were also undertaken using a two-dimensional-based morphodynamic model. The results indicated that the proposed numerical model simulated the geometry of channel network and its development process observed in the experiment reasonably well. In addition, a sensitivity analysis of grid resolution was carried out to show how grid resolution affected the computational results. The results implied that a grid size which can resolve the finer-scale channels that form in the initial stages of network development is required to simulate the evolution of tidal creeks adequately.