Forecast of development of sea coasts on their morphodynamicstate according to the results of space images descryption

The choice of the object of study is due to the alarming problem of the stability of its shores and, above all, the sandy beaches of the recreational and tourist complex of international importance Varadero, Ikakos peninsula. Its relief is represented by a low (on average 10 m) abrasion-accumulating plain with several remnants of indigenous carbonate rocks of calcarenites, the maximum elevation of which is 27 m. From the west, the peninsula is washed by the waters of the Strait of Florida, and from the east by the waters of a small shallow-water Cardenas Bay. In tectonic terms, the Ikakos Peninsula is represented by a fault-block structure complicating the centricline of the neotectonic trough of Remedios, bordering about Cuba island. Holocene deposits of the peninsula on the western side are represented by marine organogenic sand of beaches, limited by organogenic conglore breccia of the Seboruko terrace and cliffs of Miocene calcareous sandstones, and on the eastern side, where mangrove vegetation is widely developed, mainly by sediments of marshes and small shallow lagoons.

Based on the results of comparative interpretation of the Ikakos Peninsula satellite images from 2003 to 2013, a map of the types of its shores was compiled . Comparison of images of different times showed that most part of the western coastline is stable. For the accumulative part of it, this is obviously a consequence of artificial sanding, and for the abrasive part, it is a consequence of the expansion of benches with a boulder block. The beaches are most stable in the middle part of the peninsula, probably because migrating alongshore sediment fluxes from both the southern and northern sides of the peninsula rush here. The most mobile were the basal and distal parts of the peninsula.

In the short term, the morpholithodynamics of the coastal geosystem of the Ikakos Peninsula will be determined mainly by its latest tectonics and sea level kinematics. The western margin will be determined by sand reserves in the coastal shelf zone. If the peninsula maintains a tendency toward a weak and moderate uplift, the abrasion of the coasts formed by calcarenite will slow down. On sandy coastal areas with increased flotation of beach-forming material, the amount of material will be reduced. Therefore, to maintain the beaches, it will be necessary to carry out competent and timely sanding and provide measures to extinguish the energy of storm waves at a submerged slope. The distal part of the peninsula will increase. On low-lying mangrove shores, lagoons and bogging will shrink, and halophilic, mainly mangrove, vegetation will advance into the Gulf of Cardenas waters.

This work was supported  by the Russian Foundation for Basic Research, projects no. 18-05-34002, 20-05-00009 and by the Russian Science Foundation, project no. 20-17-00060.