Coastal Degradation Induced by Anthropogenic Impacts along the North Bulgarian Black Sea Shore

The present study explores modification of 10 km long coastal section between Albena sea resort and Balchik town, North Bulgarian Black Sea coast. The coastline alterations have been caused by armouring of this section as a road connection with solid coast-protection structure of a dike type. Dikes are onshore structures with the principal functions of protecting low-lying coastal territories against flooding and they are one of the most used defence methods along the Bulgarian coast. The research focuses the attention on the assessment of human-induced degradation at the study area: coastline shifting, sand losses and interruption of sediment supply from the cliff. Data from topographic maps (1:5 000) and field surveys data were used to investigate the coastal modifications, as the analysis and accurate assessment were performed into GIS environment. Dikes provide effective wave breaking and sufficiently protect the coast against flooding. On the contrary, such structures stop the exchange between land and sea, and vice versa, disrupt sediment input from the cliff, restrict public access to the water-area and decrease coastline attractiveness. In that case, as a consequence of dike construction, the 10 km long natural coast at this section was armoured and the whole coastal ecosystem was forever destroyed.