Storms are one of the most important phenomena producing coastal hazards and endangering human life and activities. In recent decades storm climate has become a subject of increased public awareness and knowledge of this issue can help the society to meet future challenges related to extreme storm manifestation. Therefore, the goal of this study is to assess trends in past and recent storminess in the western Black Sea. The analysis of storm climate is based on a continuous hindcast dataset covering a substantial historical time-span of 63 yr (1948–2010). It was used to create a storm population and to estimate properties describing storminess (proxies). This was done by introduction of criteria allowing separation of events with low probability of occurrence and at the same time keeping the information on their pattern, i.e. properties of storm phases. Eleven storminess proxies were analysed and the most indicative appeared to be storm duration; integral, mean and specific storm wave energy; and wind velocity and direction, which were obtained for each storm season. While experiencing significant variability on a quasi-decadal scale, no significant upward or downward trends in storminess were detected. For almost all proxies, an increasing trend until the 1980s or the 1990s and a return to average or even calm conditions in the late 2000s are traceable. On this background, a steady although not significant increase of wind velocity was detected. Results also indicate an alteration of storm pattern, manifested as shortening of storm duration due to a shift of the prevailing direction of storm forcing winds to the north. Nevertheless, incident wave energy in the storms' most intense phase remains significant. The obtained results are discussed with regard to the influence of the North Atlantic Oscillation on the hydrometeorological pattern of the Black Sea region as a part of the European-Atlantic area, in particular with respect to the cyclonic activity.

European coasts suffer notably from hazards caused by low-probability and high-impact hydrometeorological events. The aim of the study is to assess in probabilistic terms the magnitude of storm‐induced flooding hazard along Varna regional coast (Bulgaria, western Black Sea) and to identify susceptible coastal sectors (hotspots). The study is performed employing the Coastal Risk Assessment Framework (CRAF) developed within EU FP7 RISC-KIT project. It constitutes a screening process that allows estimation of relevant hazard intensities, extents and potential receptors’ exposure vulnerability within predefined sectors. Total water level was the chief property considered for calculation of coastal flooding hazard. It was estimated using Holman model (for sandy beaches) and EurOtop formulation (for artificial or rocky slopes). Resulting values were subjected to Extreme Value Analysis to establish that the best fitting distribution corresponds to Generalized Extreme Value distribution. Furthermore, hazard extents were modelled by means of bathtubbing or overwash estimation in order to form the flooding hazard indicator. Land use, social vulnerability, transport systems, utilities and business settings were considered as exposure indicators. Finally, potential risk was assessed by coastal indices following an index-based methodology, which combines hazard and exposure indicators into a single index, thereby providing base for comparison of coastal sectors’ vulnerability. The study found that the concentration of hotspots is highest in Varna Bay.

The study investigates cross-shore outer sand bar dynamics in an open-coast non-tidal beach at the Bulgarian Black Sea due to wave climate. On seasonal to short-term (1–2 years) time scale, monthly field measurements of the outer bar profiles were related to respective modeled nearshore wave data. Hereby, seaward-shoreward bar migration was examined depending on the wave forcing, wave non-linearity, wave transformation scenarios, storms and direction of wave incidence. Analysis revealed that intra-annually highly non-linear waves were responsible for outer bar displacement, while the direction of migration depended on wave period, duration of conditions with wave steepness >0.04, angle of approach and total duration of storms. Short-term bar evolution was mainly governed by wave height and storms’ parameters as the angle of approach and duration. The correlation between the outer bar location and wave height annual variations initiated the first for the explored Black Sea region examination of possible connection between wave height’s temporal fluctuations and the variability of climatic indices the North Atlantic Oscillation (NAO), the Atlantic Multi-decadal Oscillation (AMO), the East Atlantic Oscillation (EA), the Arctic Oscillation (AO), the East Atlantic-Western Russia (EA/WR) and the Scandinavian (SCAND) patterns. According to the results the inter-annual outer bar location may vary depending on periods of maximum annual wave fluctuations, which in turn predominantly depend on indices the EA (4–5, 10–11, 20–30 years), the EA/WR (2–4, 9–13 years) and the NAO (15 years).