IMPACT ASSESSMENT OF THE NEW FISHING PORT ON THE HYDRO AND MORPHODYNAMIC REGIME IN CHERNOMORETS BAY.

Since putting in operation of Chernomorets fishing port (Sozopol municipality, southern Bulgarian Black Sea coast) in January 2016, a number of negative effects have been observed in the area. The disturbance in the existing hydrodynamic balance led to intense coastal erosion and unwanted sand accumulation in the wave shadow area. Additionally, the coastal water quality has deteriorated in the port area. In order to undertake measures to mitigate the observed adverse effects, it is necessary to assess in detail the impact of the new facility on the hydrodynamic and morphodynamic regime in Chernomorets Bay. The assessment was done through geospatial morphological analysis based on satellite images, historical and present field observations, on one hand, and hydrodynamic and morphodynamic modelling, on the other one, which took into account the setting before and after the port construction. Typical seasonal wave conditions, related sea level variations, and a real storm situation based on field measurements during a storm surge event were simulated. The geospatial morphological analysis shows that there was a balance in the distribution of sandy material along the beach before the port construction. After the construction, a fast modification of the beach and bottom slope morphology has taken place resulting in ever increasing erosion in the north-western and western part of the bay and accumulation in the central and south-eastern one, accompanied by slope flattening. The modelling showed that the effect of the new port on the sediment dynamics is significant and completely irreversible in natural manner. This is due to the severely reduced natural system control on sediment fluxes balance. The presently observed beach erosion and coastal abrasion are expected to pursue, thus expanding the affected by both erosion and unwanted accumulation areas. [ABSTRACT FROM AUTHOR]