HYDRODYNAMICS AND ACOUSTICS

2021 ◊ Volume 2 (92) ◊ Issue 2 ◊ p. 191-203

B. M. Ostroverh^*, L. S. Potapenko^*

^* Institute of Hydromechanics of NAS of Ukraine, Kyiv, Ukraine

Study of the influence of wind waves on the siltation of the sea approach channel based on the results of modeling and field observation

Gidrodin. akust. 2021, 2(2):191-203

TEXT LANGUAGE: Ukrainian

ABSTRACT

The work is devoted to the study of the morphodynamics of the coastal zone of the deep water passage of the Danube~-- Black Sea to determine the effect of wind waves on the silting of the marine approach channel based on the use of a complex of numerical mathematical models and geographic information systems. The study was carried out based on the results of mathematical modeling and field observation for several years based on the joint use of computational complexes and applying a geographic information system for generating computational grids and analyzing the results. Wind waves and the flow and morphodynamics were calculated using the CMS-Wave spectral wave model and CMS-Flow shallow water model, respectively. A geographic information system was used to prepare initial data and analyze and process numerical results and field observations. Wave transformation was evaluated on the protecting dam of the sea approach channel. Zones of accumulation and erosion of the channel formed as a result of modeling 48 hours of storm wave impact were determined. To verify the obtained data a geographic information analysis was carried out based on the results of depth measurements in the channel and on its edges before and after the storm. The correspondence between the simulation results and the observed zones of accumulation and erosion is demonstrated. The zones of sediment accumulation in the channel occur at the head of the dam entering the sea approach channel. A sequence of bars of the transverse type associated with morphodynamic instability arising from the interaction of waves and currents occurs in the zone of wave destruction on the right edge of the channel. The long-term morphological changes under the action of storm waves in the zone of deep-water navigation were studied. The influence of protective structures on the silting of the canal is determined. An analysis of morphological changes in the coastal area indicates that currents gradually approach the river currents and the main zones of sediment accumulation are moving toward the entrance to the marine approach channel. These changes are caused by the construction of a protective dam, which naturally enters the structure of the left bank of the canal and bar formation on its right bank.

KEY WORDS

bottom morphodynamics, current, estuary, sea access channel, accumulation zone

REFERENCES