39. Empirical estimation of beach-face slope and its use for warning of berm erosion

Hyoseob Kim1, Kevin Hall2, Jae-Youll Jin3, Gyung-Soo Park4, Jeongsoo Lee5

1, 5Kookmin University, Seoul, Korea

3Korea Institute of Ocean Science and Technology, Ansan, Korea

4POSCO E&C, Pohang, Korea

3Corresponding author

E-mail: 1hkim@kookmin.ac.kr, 2k.hall@exec.uoguelph.ca, 3jyjin@kiost.ac, 4stealth@poscoenc.com, 5dlwjdtn87@nate.com

(Received 12 December 2013; received in revised form 16 December 2013; accepted 21 December 2013)

Abstract. Typical berm erosion and accretion are closely related to the beach-face slope. Empirical equation for prediction of the beach-face slope is proposed. The beach-face slope is expressed as a function of the wave period and the bed sediment grain size. Coefficients in the equation are obtained from three sets of carefully chosen laboratory data through a multiple linear regression with two independent variables using SPSS version 22. The computed correlation coefficient is as high as 0.983, which is believed to justify the validity of the present formulation. A shore profile is split into beach-face and underwater bed profile in the surf zone, and described with two straight lines. Possibility of using the beach-face slope strategically for warning of future berm erosion at the site is proposed.

Keywords: cross-shore sediment transport, beach-face, beach-face slope, erosion, warning.

References

[1]        O’Connor B. A., Kim H., Yum K. D. Modelling siltation at Chukpyon Harbour, Korea. Computer Modelling of Seas and Coastal Regions, 1992, p. 297‑410.

[2]        Watanabe A., Riho Y., Horikawa K. Beach profiles and on-offshore sediment transport. International Conference on Coastal Engineering, 1980, p. 1106‑1121.

[3]        Kajima R., Shimizu T., Maruyama K., Saito S. Experiments on beach profile change with a large wave flume. International Conference on Coastal Enigineering, 1982, p. 1385‑1404.

[4]        Bailard J. A. Modeling on-offshore sediment transport in the surfzone. International Conference on Coastal Engineering, 1982, p. 1419‑1438.

[5]        Bruun P. Coastal erosion and the development of beach profiles. Technical Memorandum No. 44, Beach Erosion Board, Coastal Engineering Research Center, US Army Engineer Waterways Experiment Station, Vicksburg, MS, 1954.

[6]        Donnelly C., Kraus N., Larson M. State of knowledge on measurement and modeling of coastal overwash. Journal of Coastal Research, Vol. 22, 2006, p. 965‑991.

[7]        Aagaard T., Black K. P., Greenwood B. Cross-shore suspended sediment transport in the surf zone. Marine Geology, Vol. 185, 2002, p. 283‑302.

[8]        Abreu T., Sancho F., Silva P. A. Generation and evolution of longshore sandbars: model intercomparison and evaluation. Coastal Dynamics, 2013, p. 51‑62.

[9]        Dubarbier B., Castelle B., Marieu V., Michallet H., Grasso F., Ruessink G. Numerical modeling of equilibrium and evolving lightweight sediment laboratory beach profiles. Coastal Dynamics, 2013, p. 521‑530.

[10]     Doering J. C., Bowen A. J. Parametrization of orbital velocity asymmetries of shoaling and breaking waves using bispectral analysis. Coastal Engineering, Vol. 26, Issue 1‑2, 1995, p. 15‑33.

[11]     Rakha K. A., Deigaard R. Importance of wave skewness in an intra-wave cross-shore sediment transport model. International Conference on Coastal Engineering, 2000, p. 3179‑3192.

[12]     Doering J. C., Elfrink B., Hanes D. M., Ruessink G. Parameterization of velocity skewness under waves and its effect on cross-shore sediment transport. International Conference on Coastal Engineering, 2000, p. 1383‑1396.

[13]     Sancho F., Abreu T., D’Alessandro F., Tomasicchio G. R., Silva P. A. Surf hydrodynamics in front of collapsing coastal dunes. Journal of Coastal Research, Vol. 64, 2011, p. 144‑148.

[14]     Rocha M., Silva P., Michallet H., Abreu T., Moura D., Moura J. Parameterizations of wave nonlinearity from local wave parameters: a comparison with field data. Journal of Coastal Research, Vol. 65, 2013, p. 374‑379.

[15]     Grasso F., Michallet H., Barthélemy E. Sediment transport associated with morphological beach changes forced by irregular asymmetric, skewed waves. Journal of Geophysical Research, Vol. 116, 2010, p. 1‑12.

[16]     Baldock T. E., Manoonvoravong P., Pham K. S. Sediment transport and beach morphodynamics induced by free long waves, bound long waves and wave groups. Coastal Engineering, Vol. 57, 2010, p. 898‑916.

[17]     Hanson H., Kraus N. C. Genesis: generalized model for simulating shoreline change. CERC Technical Report, CERC-89-19, 1989.

[18]     Dean R. G. Equilibrium beach profiles: U.S. Atlantic and Gulf coasts. Department of Civil Engineering, Ocean Engineering Report No. 12, University of Delaware, Newark, DE, 1977.

[19]     Larson M., Kraus N. C. SBEACH: Numerical model for simulating storm-induced beach change. CERC Technical Report, CERC-89-9, 1989.

[20]     Sunamura T., Horikawa K. Two-dimensional beach transformation due to waves. Proc. 14th International Conference on Coastal Engineering, 1974, p. 920‑938.

[21]     Hoque Md. A., Asano T. Numerical study on wave-induced filtration flow across the beach face. Ocean Engineering, Vol. 34, 2007, p. 2033‑2044.

[22]     Kelly D. M., Dodd N. Beach-face evolution in the swash zone. Journal of Fluid Mechanics, Vol. 661, 2010, p. 316‑340.

[23]     Walgreen M., Swart H. E. D., Calvete D. A model for grain-size sorting over tidal sand ridges. Ocean Dynamics, Vol. 54, 2004, p. 374‑384.

[24]     Sunamura T. Quantitative predictions of beach-face slopes. Geological Society of America Bulletin, Vol. 95, Issue 2, 1984, p. 242‑245.

[25]     Anthony E. J. Sediment-wave parametric characterization of beaches. Journal of Coastal Research, Vol. 14, 1998, p. 347‑352.

[26]     Masselink G., Li L. The role of swash infiltration in determining the beachface gradient: a numerical study. Marine Geology, Vol. 176, 2001, p. 139‑156.

[27]     Reis A. H., Gama C. Sand size versus beachface slope – an explanation based on the constructal law. Geomorphology, Vol. 114, 2010, p. 276‑283.

[28]     Wise R. A., Smith S. J., Larson M. SBEACH: numerical model for simulating storm-induced beach change: Report 4 Cross-shore transport under ramdom waves and model validation with supertank and field data. Coastal Engineering Technical Report CERC-89-9, 1996.

[29]     Bejan A. Advanced engineering thermodynamics. Second ed., Wiley, New York, 1997.

[30]     Birkemeier W. Professional development programme: coastal infrastructure design, construction and maintenance: a course in coastal defense system I. Chapter 2: Cross-shore sediment processes, 2001.

[31]     Lee J. C. Development of survey system of coastal shallow bathymetry. Kiost Internal Report, 2013.

[32]     Levesque R. SPSS programming and data management: a guide for SPSS and SAS users. Fourth Edition, SPSS Inc., 2007.