Đặc điểm và cơ chế hình thành các cấu trúc dòng chảy xoáy tại cửa Đề Gi, tỉnh Bình Định

Abstract

The De Gi inlet is located in Binh Dinh province, between the Nuoc Ngot lagoon and the sea, as well as the outlet of the La Tinh river basin. The De Gi inlet is frequently deposited by sand, which has had a negative impact on the operation of the fishing boat shelter inside the estuary, particularly from 2002 to the present. In 2006, a jetty was built on the estuary's southern bank to prevent sedimentation at the estuary's entrance. However, sediment continued to fill the De Gi inlet's entrance and access channel. This paper presents the simulation results of flow patterns at the De Gi inlet using the Mike 21 FM model, corresponding to simulation scenarios that are representative for wave and tidal regimes during the monsoon period. The simulation results show that the flow pattern at the De Gi inlet is driven not only by the general rules of near-shore currents on the central coast of Vietnam, but also by the formation of eddy flow structures at the estuary during the Northeast monsoon. During the ebb phase, large eddy structures form to the south of the jetty, while during the flood phase, small eddy structures form near shore. The findings also show that large eddy current structures form primarily during the ebb phase, when ebb flow from the Nuoc Ngot lagoon interacts with waves from the NE, E, and SE