Keywords
maximum wave run-up
flooding hazard
shoreline retreat
erosion hazard
empirical models
How to Cite
Abstract
European coasts suffer significantly from hazards caused by low-probability and high-impact hydro-meteorological events. The aim of the study is to assess in probabilistic terms the magnitude of storm†induced flooding and erosion hazards along Varna regional coast (Bulgaria, western Black Sea). 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 and extents within predefined sectors. Since total water level was the chief property considered for determination of coastal flooding hazard, the accurate calculation of maximum wave induced run-up is of utter importance. Therefore, a central part of the study is testing the applicability and validation of three empirical models - from which the Holman model was preferred to be applied on sandy beaches, as well as EurOtop formulation for artificial or rocky slopes. As for erosion hazard, the performance of the convolution model was assessed and subsequently employed for evaluation of shoreline retreat. Quantification of hazard intensities allowed hinterland extent to be roughly delineated. As a final result of the study, hazard indicators were obtained for both flooding and erosion, which were subsequently mapped and used for identification of the most susceptible sectors along the regional coast. It was found that their concentration is highest in Varna Bay.References
Battjes, J.A. 1974. Surf similarity. Proceedings of the 14th International Conference of Coastal Engineering (American Society of Civil Engineers), pp. 466-480.
Battjes, J.J.A. 1971. Runup distributions of waves breaking on slopes, Journal of the Waterways, Harbours and Coasts Engr. Div., ASCE, 97 WW1, 91-114.
Bruun, P. 1962. Sea level rise as a cause of shore erosion, Journal of Waterways and Harbors Division, 88(1), 117- 130.
Dean, R.G. and E.M Maurmeyer. 1983. Models for beach profile response. In: Komar, P. (Ed.), Handbook of Coastal Processes and Erosion. CRC Press, Boca Raton, 151- 165.
Dimitrov D., Nyagolov I., Balabanova S., Lisev N., Koshinchanov G., Korcheva A., Marinski Y., Pashova L., Grozdev D., Vasilev V., Bozhilov and N. Tsvetkova. 2013. Methods for assessment of flood hazard and flood risk, according to requirements of the EU Floods Directive 2007/60: Final Report, Black Sea Basin Directorate, Contract No D-30-62, 357 p. (In Bulgarian).
Donnelly, C. 2008. Coastal Overwash: Processes and Modelling. Ph.D. Thesis, University of Lund, 53 pp.
Douglass, S. 1992. Estimating extreme values of runup on beaches, Journal of Waterway, Port, Coastal and Ocean Engineering, 118(2): 220-224.
Edelman, T. 1972. Dune erosion during storm conditions. Proceedings of the 13th Coastal Engineering Conference, ASCE, 1305-1311.
Ferreira, O., C. Viavattene, J. Jimenes, A. Bole, T. Plomaritis, S. Costas and S. Smets. 2016. CRAF Phase 1, a framework to identify coastal hotspots to storm impacts, Proceedings of 3rd European Conference on Flood Risk Management FLOODrisk 2016, E3S Web of Conferences 7, 10002.
Garrity, N.J., R. Battalio, P.J. Hawkes and D. Roupe. 2006. Evaluation of the event and response approaches to estimate the 100†year coastal flood for Pacific coast sheltered waters, Proceeding of the 30th ICCE, ASCE, 1651†1663.
Hedges, T. and M. Reis. 1998. Random wave overtopping of simple seawalls: a new regression model. Water, Maritime and Energy Journal, 1(130), 1-10.
Holman, R.A. 1986. Extreme value statistics for wave run-up on a natural beach, Coastal Engineering, Elsevier, 9 (6), 527-544.
Hunt, I.A. 1959. Design of seawalls and breakwaters. Journal ofWaterways and Harbours Division, ASCE 85 (WW3), 123-152.
Kobayashi, N. 1987. Analytical solution for dune erosion by storms, Journal of Waterway, Port, Coastal, and Ocean Engineering, 113(4), 401-418.
Komar, P. and M. Gaughan. 1973. Airy wave theory and breaker height prediction. Proceedings of the 13th Coastal Engineering Conference, ASCE, 405-418.
Kriebel, D. and R. Dean. 1993. Convolution Method for Time†Dependent Beach†Profile Response, J. Waterway, Port, Coastal, Ocean Eng., 119(2), 204-226.
Larson, M., L. Erikson, and H. Hanson. 2004. An analytical model to predict dune erosion due to wave impact, Coastal Engineering, 51, 675-696.
Mase, H.1989. Randomwave run-up height on gentle slope. Journal of Waterway, Port, Coastal, and Ocean Engineering, 115(5), 649-661.
Nielsen, P. and D.J. Hanslow. 1991. Wave run-up distributions on natural beaches, Journal of Coastal Research, CERF. 7(4), 1139-1152.
Orton, P., S. Vinogradov, A. Blumberg and N. Georgas. 2014. Hydrodynamic mapping of future coastal flood hazards for New York City, Revised final project report, Stevens Institute of Technology, 36 pp.
Overton, M.F., J.S. Fisher and T. Fenaish. 1987. Numerical analysis of swash forces on dunes. Proceedings of Coastal Sediments '87, ASCE, 632- 641.
Overton, M.F., W.A. Pratikto, J.C. Lu and J.S. Fisher. 1994. Laboratory investigation of dune erosion as a function of sand grain size and dune density, Coastal Engineering, 23, 151- 165.
Park, H. and D. Cox. 2016. Empirical wave run-up formula for wave, storm surge and berm width, Coastal Engineering, Elsevier, 115, 67-78.
Pullen, T., N.W.H. Alsop, T. Bruce, A. Kortenhaus, H. Schuttrumpf and J.W. van der Meer. 2007. EurOtop. Wave overtopping of sea defenses and related structures: Assessment manual, Flood Risk Management: Research and Practice - Samuels et al. (eds.), Taylor & Francis Group, London, 193 pp.
Reis, M., K. Hu, T. Hedges and H. Mase. 2008. A comparison of empirical, semiempirical and numerical wave overtopping models, Journal of Coastal Research, 24, 250-262.
Ruggiero, P., P.D. Komar, W.G. McDougal, J.J. Marra, and R.A. Beach. 2001. Wave runup, extreme water levels and the erosion of properties backing beaches, Journal of Coastal Research, 17(2), 407-419.
Sallenger, A.H. 2000. Storm impact scale for barrier islands, Journal of Coastal Research, 16 (3), 890-895.
Slocum, T. A. 1999. Thematic cartography and Visualization. Upper Saddle River: Prentice Hall Inc.
Stanchev, H., R. Young and M. Stancheva. 2013. Integrating GIS and high resolution orthophoto images for the development of a geomorphic shoreline classification and risk assessment - a case study of cliff/bluff erosion along the Bulgarian coast, Journal of Coastal Conservation, 17(4), 719-728.
Stockdon, H. F., R.A. Holman, P.A. Howd and A.Jr. Sallenger. 2006. Empirical parameterization of setup, swash, and run-up, Coastal Engineering, Elsevier, 53(7), 573-588.
Trifonova E., N. Valchev N. Andreeva and P. Eftimova. 2012. Critical storm thresholds for morphological changes in the western Black Sea coastal zone, Geomorphology, Elsevier, 143-144, 81-94.
Valchev, N., E. Trifonova and N. Andreeva. 2012. Past and recent trends in the western Black Sea storminess, Nat. Hazards Earth Syst. Sci., 12, 1-17.
Valchev, N., N. Andreeva, P. Eftimova, B. Prodanov and I. Kotsev. 2016. Assessment of vulnerability to storm induced flood hazard along diverse coastline settings, Proceedings of 3rd European Conf. on Flood Risk Management, FLOODrisk 2016, E3S Web of Conferences 7 10002.
Van Dongeren, A., P. Ciavola, G. Martinez, C. Viavattene, S. DeKleermaeker, O. Ferreira, C. Costa and R. McCall. 2016. RISC-KIT: Resilience-increasing Strategies for Coasts, Proceedings of 3rd European Conf. on Flood Risk Management, FLOODrisk 2016, E3S Web of Conferences 7 17001.
Vellinga, P. 1986. Beach and dune erosion during storm surges. PhD thesis, Delft Hydraulics Communications No. 372, Delft Hydraulics Laboratory, Delft, The Netherlands.
Weggel R.J. 1972. Maximum breaker height.Journal of the Waterways, Harbors and Coastal Engineering Division, ASCE 1972, 98(4), 529-548.
Wright, L.D. and A.D. Short. 1984. Morphodynamic variability of surf zones and beaches: a synthesis. Marine Geology, Elsevier, 56, 93-118.