The Mechanism of Large-Scale Flow Circulation at Asymmetric Sand Spit Inlet: A Case Study in Degi Estuary, Binh Dinh Province

Vietnam’s south central coast, from the Quang Ngai province to the Binh Thuan province, is characterized by many asymmetrical inlets with a protruding rocky headland on one side and an elongated sand spit on the other side. The rocky headlands can be located in the North, such as at De Gi inlet and the Tam Quan inlet, or in the South, such as at the My A inlet and the Da Nong inlet. Under certain hydrodynamic conditions, a large-scale flow circulation may emerge at these inlets due to the asymmetrical topography. However, the formation mechanisms and hydrodynamic parameters that drive the evolution of a large-scale flow circulation of asymmetrical sand spit inlet have not been clarified. This paper describes simulated flow patterns at De Gi inlet in the Binh Dinh province under various wave and tide conditions. The findings, based on numerical simulation results, will reveal the mechanism of large-scale flow circulations and their relationship to the physical characteristics of sand spit inlets on Vietnam's South Central Coast.