The Variability of the Beach Morphology and the Evolution of the Shoreline in the Strongly Anthropized Sector of Eforie North, the Romanian Coast of the Black Sea

Abstract

The Eforie Nord sector (between the southern pier of Agigea - Constanta port and the tourist port of Belona), is characterized, from a geomorphological point of view by the presence of high cliffs and narrow beaches. In the mentioned sector, a series of coastal protection works were carried out in several stages, respectively: between 1956 and 1960, 6 groins were placed to extend the perimeter beach; with the expansion of Constanța port, new coastal protection measures were imposed (1981-1986), determined by the erosion processes, made concrete by the execution of permeable submerged longitudinal dikes in addition to the transversal ones. On long term, the measurements of shore morphological parameters highlighted that the southern sector of the Romanian Black Sea coast is subject to an erosion process, due to the action of both natural and anthropogenic factors, each generating effects with different intensity, depending on local conditions. Within the project “Protection and Rehabilitation of the Southern Part of the Romanian Black Sea Coast, Phase 1” in 2014-2015 period, in the mentioned sector, extended hydrographical works were carried out, including the rehabilitation of dikes, the construction of submerged dikes and beach nourishment. The monitoring of the shore behavior at regular intervals (annual/seasonal) which is essential for an adequate management of the coastal area, highlights both cyclical/seasonal morphological changes (rapid erosion as a result of storms in the cold season and the reconstruction of the beach during summer) and progressive/multiannual changes. The monitoring of morpho dynamic changes at shore level includes the positioning of the shoreline and beach profiles in 6 locations using GPS equipment (geodetic and GIS class). The resulting spatial data were processed and included in the SANDS management system that allows comparative analysis at different time scales. The maps representations were made in the ArcGIS 10.8 system. The data analysis revealed seasonal changes of the shore morphology, both in the longitudinal profile (shoreline) and transversally (beach profiles).