Численное моделирование сгонно-нагонных колебаний в заливе Донузлав (Черное море)

Abstract

Surge oscillations in the coastal zone of the seas can have a significant impact on the infrastructure and safety of navigation in bays and bays. The purpose of this work is to study the surge oscillations in the Donuzlav Bay located on the western coast of the Crimean Peninsula and connected to the sea by a narrow strait. The Advanced Circulation Model for Shelves Coasts and Estuaries (ADCIRC) is used for this. The numerical algorithm of the model is based on the finite element method using triangular elements and linear basis functions. The input data of the ADCIRC model were the surface wind velocity and atmospheric pressure fields over the Black Sea. Numerical modeling was performed on two nested unstructured grids. The first grid included the entire Black Sea, the second grid included the bay and the adjacent sea area. To graphically display the simulation results, the Generic Mapping Tools (GMT) mapping package was used. Analysis of the simulation results for different wind directions showed that when the wind acts on the water area of the Donuzlav Bay, seiche-like oscillations occur in the fields of sea level and currents. The intensity of these fluctuations is determined by how quickly the wind speed reaches its maximum value. Owing to the narrowness of the strait outside the bay, fluctuations do not appear. Modeling of an extreme storm situation that occurred in the Black Sea on November 11, 2007 was carried out. During the storm, a rapid change in wind direction from southeast to west occurred with a simultaneous increase in wind speed to 15–21 m/s. This caused a rise in sea level at the top of the bay to 0.5 m and an increase in the current velocity in the strait to 0.6 m/s.