статья в журнале

En

Ecological Safety of Coastal and Shelf Zones of Sea

ISSN:2413-5577

2024

OILBDL

Artificial beaches are one of the most effective methods of protecting shores and hydraulic structures under shortage of natural beach-forming material. This work investigates the influence of extreme storms on the erosion zone width of an artificial pebble beach located in front of a vertical concrete seawall in the village of Koktebel (Feodosia, Crimea). The storm power index in the central part of Koktebel Bay was calculated on the basis of wind wave reanalysis data for 1979-2020 obtained using the SWAN spectral model and ERA-Interim and ERA5 surface wind fields. We identified 146 storm situations with duration of at least 12 hours. Three most extreme storms were analysed: in terms of power index (660 m2∙h), the storm of 26-29 January 1988; in terms of mean significant wave height (3.6 m), the storm of 10-11 November 2007; and in terms of duration (95 h), the storm of 25-29 September 2017. The profile deformations of the artificial pebble beach attached to a vertical concrete seawall were calculated for the first and second storms using a one-dimensional version of the XBeach (eXtreme Beach behavior) numerical model. It was shown, that under the impact of storm waves, the coast steepness near the coastline changes gradually and material from the beach nearshore part slid down the underwater slope leading to a local depth decrease near the shore. It was found, that the underwater erosion zone width of the beach was three times greater than the surface one. The most significant deformations of the beach profile occurred during the first 6 hours of storm action, and then the rate of beach deformation decreased. It was obtained that the coastline in the area of interest could retreat up to 10 m under the impact of an extreme storm. The study revealed that ≥ 20 m wide pebble beaches (a mean particle size of 30 mm) would fully absorb the wave energy of extreme storms and provide adequate protection for the coastal zone of Koktebel Bay.

ПЛЯЖ, БЕРЕГОЗАЩИТНЫЕ СООРУЖЕНИЯ, ВЕТРОВОЕ ВОЛНЕНИЕ, ЭКСТРЕМАЛЬНЫЙ ШТОРМ, XBEACH, КРЫМ, КОКТЕБЕЛЬ, beach, coast protection structures, Crimea, extreme storm, Koktebel, wind waves, XBeach

2025-01-10 14:22:49