Influence of the climatic variations in the wind waves parameters on the alongshore sediment transport

Abstract

• The purpose of this work was to analyze the climatic variability of wind waves and swell parameters in the coastal zone on the sediment transport and to assess the contribution of the swell to the formation of alongshore fluxes. • The applied method is mathematical modeling. • Over the past 39 years, the role of swell has been increasing. • Obtained results allowed us to estimate climatic changes in the surface wave structure, as well as the effect of these changes on the characteristics of the coastal sediment transport. The purpose of this work was to analyze the influence of climatic variability of wind waves and swell parameters in the coastal zone on the sediment transport and to assess the contribution of the swell to the formation of alongshore fluxes. The object of research is the Anapa bay-bar (the Black Sea). Mathematical modeling has shown that in the Anapa bay-bar area the average annual wind waves and swell powers have significant interannual variability. For the period from 1979 to 2017, in the southern part of the bay-bar, there was a statistically significant decrease in the share of swell in the alongshore transport, directed from NW to SE, in the central part – an increase in the contribution of swell to the total sediment flow from SE to NW, in the northern part – probable increase in flows to NW and decrease – to SE. Such a dynamic is consistent, in general, with experimental observations of the processes of erosion and accumulation of beach-forming material along the Anapa bay-bar coastline. A separate description of the bottom sediment fluxes under the influence of wind waves and swell made it possible to explain the fluctuations of the coastline over a climatic period.