Journal cover Journal topic
Natural Hazards and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Nat. Hazards Earth Syst. Sci., 16, 167-180, 2016
http://www.nat-hazards-earth-syst-sci.net/16/167/2016/
doi:10.5194/nhess-16-167-2016
© Author(s) 2016. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
19 Jan 2016
Run-up parameterization and beach vulnerability assessment on a barrier island: a downscaling approach
G. Medellín1,2, J. A. Brinkkemper3, A. Torres-Freyermuth2, C. M. Appendini2, E. T. Mendoza2, and P. Salles2 1Cátedras-CONACyT, Consejo Nacional de Ciencia y Tecnología, Ciudad de México, Mexico
2Laboratorio de Ingeniería y Procesos Costeros, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Sisal, Mexico
3Department of Geosciences, Utrecht University, Utrecht, the Netherlands
Abstract. We present a downscaling approach for the study of wave-induced extreme water levels at a location on a barrier island in Yucatán (Mexico). Wave information from a 30-year wave hindcast is validated with in situ measurements at 8 m water depth. The maximum dissimilarity algorithm is employed for the selection of 600 representative cases, encompassing different combinations of wave characteristics and tidal level. The selected cases are propagated from 8 m water depth to the shore using the coupling of a third-generation wave model and a phase-resolving non-hydrostatic nonlinear shallow-water equation model. Extreme wave run-up, R2%, is estimated for the simulated cases and can be further employed to reconstruct the 30-year time series using an interpolation algorithm. Downscaling results show run-up saturation during more energetic wave conditions and modulation owing to tides. The latter suggests that the R2% can be parameterized using a hyperbolic-like formulation with dependency on both wave height and tidal level. The new parametric formulation is in agreement with the downscaling results (r2  =  0.78), allowing a fast calculation of wave-induced extreme water levels at this location. Finally, an assessment of beach vulnerability to wave-induced extreme water levels is conducted at the study area by employing the two approaches (reconstruction/parameterization) and a storm impact scale. The 30-year extreme water level hindcast allows the calculation of beach vulnerability as a function of return periods. It is shown that the downscaling-derived parameterization provides reasonable results as compared with the numerical approach. This methodology can be extended to other locations and can be further improved by incorporating the storm surge contributions to the extreme water level.

Citation: Medellín, G., Brinkkemper, J. A., Torres-Freyermuth, A., Appendini, C. M., Mendoza, E. T., and Salles, P.: Run-up parameterization and beach vulnerability assessment on a barrier island: a downscaling approach, Nat. Hazards Earth Syst. Sci., 16, 167-180, doi:10.5194/nhess-16-167-2016, 2016.
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Short summary
This work presents a methodology to conduct a probabilistic analysis of the storm impact on a barrier island. A subset of wave conditions from a 30-year hindcast is propagated to the shore to predict the extreme run-up. Subsequently, a 30-year run-up hindcast is estimated using a multivariate interpolation technique. This information is used to derive a new run-up parameterization that predicts both the run-up saturation and its dependency on sea level as observed in the downscaling results.
This work presents a methodology to conduct a probabilistic analysis of the storm impact on a...
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