A Lithodynamic Analysis of the Coastal Zone within the Utrish State Nature Reserve (North-Eastern Black Sea Coast)

Aim . To investigate the structure, dynamics of the coastal zone relief of the Utrish Nature Reserve, and its main types, based on the lithodynamic characteristics of the coast. Methodology . In 2023–2025, several cycles of field surveys were conducted along a 9-km coastline within the Utrish Nature Reserve. A standard complex of field studies was carried out across 90 profiles (spaced at 100-meter intervals), comprising morphometric measurements; photography (including imagery for subsequent photogrammetric processing); assessment of the composition and condition of beach deposits (including sample collection for later analysis); and descriptions of the topography and visible signs of landform-shaping processes. Laboratory processing of the collected samples was performed, followed by the synthesis and analysis of the accumulated data, archival records, and remote sensing data. Results . Based on a review of published literature and original data, it has been confirmed that the morphology of the coastal section under consideration was shaped by Holocene seismogravitational events, namely large-scale rockfalls and landslides. Due to the fragmentation of the coast by landslide bodies, which formed headlands that act as impassable barriers to sediment transport, the coastal zone functions as a system of isolated littoral cells. Marked contrasts in wave energy intensity and the distribution of sediment sources result in high variability in beach width. Across the entire section, the average beach width was 19.5 m. Slope denudation processes serve as the primary source of beach-forming material, with the beach sediments being dominated by pebbles and gravel. The study concludes that a state of dynamic equilibrium currently exists between abrasion and accumulation, with no pronounced trend of shoreline retreat. Research implications . A classification of the above-water part of the coastal zone within the Utrish Nature Reserve is proposed, and lithodynamic characteristics are summarised, serving as a basis for organising monitoring, the purpose of which is to assess the resilience of the coastal landscapes of the reserve to the impact of a number of such extreme natural phenomena as storms, heavy rains, avalanches and landslides, as well as to a gradual rise in sea level.