SEABED MORPHOLOGY OF THE VARNA BAY COASTAL ZONE, BULGARIAN BLACK SEA

Shallow coastal bedforms are formed in a highly dynamic environment due to natural and anthropogenic factors. The combined action of climate, waves, river inputs, tidal currents, sea level rise, and coastal geology shapes their morphology at different temporal and spatial scales. Integration of various data sets collected by different survey methods like multi-beam sonar system, single-beam echo sounder, orthophoto imaging, and complemented by data from seafloor sediment sampling, allowed for the compilation of an extensive geo-database and subsequent analysis of the coastal geomorphology (processes and bedforms) of Varna Bay in a GIS environment. As a result, a comprehensive seafloor geomorphological map of Varna Bay was created. The coastal zone, with respect to local hydrodynamics, is divided into the following subzones: active subzone, steady subzone, non-active subzone and anthropogcnic subzone. The conducted detailed morphometric analysis and study of the coastal zone tectonics, geo- and morphodynamics gave us reasoning to localize specific bedforms of a depositional, erosional, landslide, structural (rocky) and anthropogenic nature.