Open AccessArtificial beach as a structure to defend a sea coast from the storm surge impact (based on the example of the eastern Gulf of Finland)
Author(s) -
I. O. Leont’yev,
И. О. Леонтьев
Publication year - 2019
Publication title -
okeanologiâ
Language(s) - English
Resource type - Journals
ISSN - 0030-1574
DOI - 10.31857/s0030-1574592292-301
Subject(s) - berm , storm surge , storm , beach nourishment , geology , oceanography , coastal erosion , breakwater , dredging , seabed , coastal engineering , plage , sediment , sediment transport , erosion , hydrology (agriculture) , shore , geotechnical engineering , geomorphology
The model of artificial beach to protect a sea coast subjected to erosion under impact of significant storm surge is suggested. The beach profile properties are based on the concept of equilibrium profile by Dean. It is shown that the use of coarser sand provides greater total width of beach, but requires greater volume of constructional berm. At the same time, the loss of material due to longshore sediment transport decreases. Application of the model to three segments of eroded coast in Kurortniy region of St. Petersburg (Eastern Gulf of Finland) allows recommend the medium sand 0.3–0.5 mm to construct the artificial beach. In this case, the width of dry beach section would be about 80–140 m, while the volume of constructional berm would be (1.3÷3.2)×102 m3/m depending on sediment deficit in a given coastal segment. In order to minimize the relative loss of material it is suggested to construct the beach of which the length is not less than 1 km. In this case, more than half of initial beach volume would be kept even after 30 years. Modeling of extreme storm impact leads to conclusion that the designed beach profiles are only slightly deformed and able conserve their resource over a long time.