SEA LEVEL REGIME OF THE BLACK SEA IN THE ANALYSIS OF SHORELINE DYNAMICS BASED ON REMOTE SENSING DATA: A CASE STUDY OF THE COASTAL AREA NEAR LEBEDIVKA

Problem Statement and Purpose. Under current conditions, remote sensing has become one of the few accessible sources of information for studying shoreline displacement, emphasizing the need to improve coastal monitoring methods using remote sensing data and to analyze their capabilities. This study aims to assess the role of sea level regime in the analysis of shoreline dynamics based on satellite imagery and to determine the necessity of accounting for the sea level variations in such analyses. Data & Methods. The study used satellite imagery from Sentinel-2 and WorldView-2 satellite systems, bathymetric data from the Navionics Sonar Chart (TM) map, and hydrometeorological data of the Black Sea from the State Hydrometeorological Service of Ukraine. The delineation of water and land surfaces on satellite imagery was performed using the Normalized Difference Water Index (NDWI). Statistical characteristics of shoreline displacement dynamics were calculated using the Digital Shoreline Analysis System (DSAS) module. Results. It was found that the water level of the Black Sea varies significantly with clearly defined seasonal patterns. Accordingly, the most appropriate period for analyzing shoreline dynamics based on satellite images is summer, when the amplitude of sea level fluctuations is minimal, reducing the risk of errors in the absence of sea level data. The relationship between sea level and shoreline displacement, as observed in satellite imagery, shows a moderate positive correlation: an increase in sea level corresponds to landward shoreline displacement. This confirms the influence of sea level on shoreline positioning in satellite-based analyses. A comparison of shoreline change rates in the Lebedivka area for the period 2013–2021, calculated using DSAS without sea level correction, and the adjusted results that account for sea level fluctuations, revealed a significant difference. This highlights that ignoring sea level regime in satellite-based shoreline dynamics assessments can lead to substantial errors in determining the rate of shoreline movement.