The analysis of the evolution of a sand bar and its formation in the Huangmao Bay of the Zhujiang Estuary

The DEM model is established using the bathymetric maps of years of 1977,1994,2003 and 2010,and combined with the 2D model,the evolution of a sand bar in the Huangmao Bay and its formation are studiod in recent 30 a.show that the sandtbar moves to the sea and becemes smaller,its inner slope and top are scoured and outer slope is silted.The formation of the sand bar is mainly located in the weak dynamic zone of the transitional zone between flood flow dominant and ebb flow dominant zones.The decrease of the tidal volume,the weakening of the tidal dynamics and the relative strengthening of the runoff caused by large reclamation,which result in that the ebb flow controlled zone is enlarged,the flood flow controlled zone reduces and the transitional zone moves down,are the main reasons of the sand bar evolution.The reduction of sediment transported by the runoff also contributes to the sand bar evolution.