Skip to main content

Coastal vulnerability assessment based on video wave run-up observations at a mesotidal, steep-sloped beach


Coastal imagery obtained from a coastal video monitoring station installed at Faro Beach, S. Portugal, was combined with topographic data from 40 surveys to generate a total of 456 timestack images. The timestack images were processed in an open-access, freely available graphical user interface (GUI) software, developed to extract and process time series of the cross-shore position of the swash extrema. The generated dataset of 2% wave run-up exceedence values R 2 was used to form empirical formulas, using as input typical hydrodynamic and coastal morphological parameters, generating a best-fit case RMS error of 0.39 m. The R 2 prediction capacity was improved when the shore-normal wind speed component and/or the tidal elevation η tide were included in the parameterizations, further reducing the RMS errors to 0.364 m. Introducing the tidal level appeared to allow a more accurate representation of the increased wave energy dissipation during low tides, while the negative trend between R 2 and the shore-normal wind speed component is probably related to the wind effect on wave breaking. The ratio of the infragravity-to-incident frequency energy contributions to the total swash spectra was in general lower than the ones reported in the literature E infra/E inci > 0.8, since low-frequency contributions at the steep, reflective Faro Beach become more significant mainly during storm conditions. An additional parameterization for the total run-up elevation was derived considering only 222 measurements for which η total,2 exceeded 2 m above MSL and the best-fit case resulted in RMS error of 0.41 m. The equation was applied to predict overwash along Faro Beach for four extreme storm scenarios and the predicted overwash beach sections, corresponded to a percentage of the total length ranging from 36% to 75%.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11


  • Aagaard T, Holm D (1989) Digitization of wave runup using video records. J Coast Res 5:547–551

    Google Scholar 

  • Almeida LP, Ferreira Ó, Pacheco A (2010) Thresholds for morphological changes on an exposed sandy beach as a function of wave height. Earth Surf Proc Landforms 36:523–532

    Article  Google Scholar 

  • Almeida LP, Ferreira Ó, Vousdoukas M, Dodet G (2011a) Historical variation and trends in storminess along the Portuguese south coast. Nat Hazards Earth Syst Sci. doi:10.5194/nhess-11-1-2011

  • Almeida LP, Vousdoukas MI, Ferreira ÓM, Rodrigues BA, Matias A (2011b) Thresholds for storm impacts on an exposed sandy coastal area in southern Portugal. Geomorphology. doi:10.1016/j.geomorph.2011.04.047

  • Baldock TE, Holmes P (1999) Simulation and prediction of swash oscillations on a steep beach. Coast Eng 36(3):219–242

    Article  Google Scholar 

  • Battjes JA (1974) Surf similarity. In: 14th Conference on Coastal Engineering. ASCE, pp 466–480

  • Bouguet J-Y (2007) Camera Calibration Toolbox for Matlab.

  • Briganti R, Bellotti G, Franco L, De Rouck J, Geeraerts J (2005) Field measurements of wave overtopping at the rubble mound breakwater of Rome-Ostia yacht harbour. Coast Eng 52(12):1155–1174

    Article  Google Scholar 

  • Dean RG (2001) Beach nourishment: theory and practice. Advanced series on ocean engineering. World Scientific, London

    Google Scholar 

  • Douglass SL (1990) Influence of wind on breaking waves. J Waterw Port Coast Ocean Eng 116(6):651–663

    Article  Google Scholar 

  • Douglass SL (1992) Estimating extreme values of run-up on beaches. J Waterw Port Coast Ocean Eng 118(2):220–224

    Article  Google Scholar 

  • Erikson LH, Hanes DM, Barnard PM, Gibbs AE (2006) Swash zone characteristics at Ocean Beach, San Francisco, CA. In: 30th International Conference on Coastal Engineering, Los Angeles

  • Ferreira Ó, Vousdoukas MV, Ciavola P (2009) MICORE review of climate change impacts on storm occurrence (open access, Deliverable WP1.4).

  • Ferreira Ó, Garcia T, Matias A, Taborda R, Dias JA (2006) An integrated method for the determination of set-back lines for coastal erosion hazards on sandy shores. Cont Shelf Res 26(9):1030–1044

    Article  Google Scholar 

  • Folk RL (1980) Petrology of the sedimentary rocks. Hemphill, Austin

    Google Scholar 

  • Fredsoe JE, Deigaard R (1992) Mechanics of coastal sediment transport. Advanced series on ocean engineering. World Scientific, London

    Book  Google Scholar 

  • Hartley R, Zisserman A (2006) Multiple view geometry in computer vision. Cambridge University Press, Cambridge

    Google Scholar 

  • Holland KT, Holman RA (1991) Measuring run-up on a natural beach II. EOS Trans Am Geophys Union 72:254

    Google Scholar 

  • Holland KT, Holman RA (1993) The statistical distribution of swash maxima on natural beaches. J Geophys Res 87:10271–10278

    Article  Google Scholar 

  • Holland KT, Raubenheimer B, Guza RT, Holman RA (1995) Run-up kinematics on a natural beach. J Geophys Res 100(C3):4985–4993

    Article  Google Scholar 

  • Holman RA (1986) Extreme value statistics for wave run-up on a natural beach. Coast Eng 9:527–544

    Article  Google Scholar 

  • Holman RA, Guza RT (1984) Measuring run-up on a natural beach. Coast Eng 8:129–140

    Article  Google Scholar 

  • Holman RA, Stanley J (2007) The history and technical capabilities of Argus. Coast Eng 54(6–7):477–491

    Article  Google Scholar 

  • Hunt IA (1959) Design of seawalls and breakwaters. J Waterw Harb Div ASCE 85(WW3):123–152

    Google Scholar 

  • Iribarren CR, Nogales C (1949) Protection des Ports. In: XVIIth International Navigation Congress, Lisbon, Portugal

  • Karambas TV, Koutitas C (2002) Surf and swash zone morphology evolution induced by nonlinear waves. J Waterw Port Coast Ocean Eng 128(3)

  • Korycansky DG, Lynett PJ (2007) Run-up from impact tsunami. Geophys J Int 170:1076–1088

    Article  Google Scholar 

  • Kroon A, Davidson MA, Aarninkhof SGJ, Archetti R, Armaroli C, Gonzalez M, Medri S, Osorio A, Aagaard T, Holman RA, Spanhoff R (2007) Application of remote sensing video systems to coastline management problems. Coast Eng 54(6–7):493–505

    Article  Google Scholar 

  • Larson M, Kubota S, Erikson L (2004) Swash-zone sediment transport and foreshore evolution: field experiments and mathematical modeling. Mar Geol 212(1–4):61–79

    Article  Google Scholar 

  • Lin P, Liu PL-F (1998) A numerical study of breaking waves in the surf zone. J Fluid Mech 359:239–264

    Article  Google Scholar 

  • MacMahan JH, Thornton EB, Stanton TP, Reniers AJHM (2005) RIPEX: observations of a rip current system. Mar Geol 218(1–4):113–134. doi:10.1016/j.margeo.2005.03.019

    Article  Google Scholar 

  • MacMahan JH, Thornton EB, Reniers AJHM (2006) Rip current review. Coast Eng 53(2–3):191–208

    Article  Google Scholar 

  • Mase H (1988) Spectral characteristics of random wave run-up. Coast Eng 12:175–189

    Article  Google Scholar 

  • Masselink G (1998) The effect of sea breeze on beach morphology, surf zone hydrodynamics and sediment resuspension. Mar Geol 146(1–4):115–135

    Article  Google Scholar 

  • Mei CC (1994) The applied dynamics of ocean surface waves. In: Advanced series on ocean engineering, vol. 1. World Scientific, London

  • Munoz-Perez JJ, de San L, Roman-Blanco B, Gutierrez-Mas JM, Moreno L, Cuena GJ (2001) Cost of beach maintenance in the Gulf of Cadiz (SW Spain). Coast Eng 42(2):143–153

    Article  Google Scholar 

  • Otsu N (1979) A threshold selection method from gray-level histograms. IEEE Trans Syst Man Cybern 9:62–66

    Article  Google Scholar 

  • Pearre NS, Puleo JA (2009) Quantifying seasonal shoreline variability at Rehoboth Beach, Delaware, using automated imaging techniques. J Coast Res 25(4):900–914

    Article  Google Scholar 

  • Pires HO (1998) Preliminary report on the wave climate at Faro. Project India. Instituto de Meteorologia–Instituto Superior Técnico, Portugal

    Google Scholar 

  • Raubenheimer B, Guza RT (1996) Observations and predictions of runup. J Geophys Res 101:25575–25587

    Article  Google Scholar 

  • Ruessink BK, Kleinhans MG, van den Beukel PGL (1998) Observations of swash under highly dissipative conditions. J Geophys Res 103:3111–3118

    Article  Google Scholar 

  • Ruggiero P, Komar PD, McDougal WG, Marra JJ, Beach RA (2001) Wave runup, extreme water levels and the erosion of properties backing beaches. J Coast Res 17(2):407–419

    Google Scholar 

  • Ruggiero P, Holman RA, Beach RA (2004) Wave run-up on a high-energy dissipative beach. J Geophys Res 109(C06025). doi:10.1029/2003JC002160

  • Sallenger AH (2000) Storm impact scale for barrier islands. J Coast Res 16:890–895

    Google Scholar 

  • Schaffer HA, Madsen PA, Deigaard R (1993) A Boussinesq model for waves breaking in shallow water. Coast Eng 20:185–202

    Article  Google Scholar 

  • Smith KR, Bryan KR (2007) Monitoring beach volume using a combination of intermittent profiling and video imagery. J Coast Res 23(4):892–898

    Article  Google Scholar 

  • Stockdon HF, Holman RA, Howd PA, Sallenger JAH (2006) Empirical parameterization of setup, swash, and runup. Coast Eng 53(7):573–588

    Article  Google Scholar 

  • Synolakis CE (1987) The run-up of solitary waves. J Fluid Mech 185:523–555

    Article  Google Scholar 

  • Ting FCK, Kirby JT (1995) Dynamics of surf-zone turbulence in a strong plunging breaker. Coast Eng 24(3–4):177–204

    Article  Google Scholar 

  • US Army Corps of Engineers (2002) Coastal engineering manual. Engineer manual 1110-2-1100 (in 6 volumes). US Army Corps of Engineers, Washington, DC

    Google Scholar 

  • Veeramony J, Svendsen IA (2000) The flow in surf-zone waves. Coast Eng 39(2–4):93–122

    Article  Google Scholar 

  • Velegrakis AF, Vousdoukas MI, Vagenas AM, Karambas T, Dimou K, Zarkadas T (2007) Field observations of waves generated by passing ships: a note. Coast Eng 54:369–375

    Article  Google Scholar 

  • Vousdoukas MI, Velegrakis AF, Dimou K, Zervakis V, Conley DC (2009a) Wave run-up observations in microtidal, sediment-starved pocket beaches of the Eastern Mediterranean. J Mar Syst 78(Supplement 1):S37–S47

    Article  Google Scholar 

  • Vousdoukas MI, Velegrakis AF, Karambas TV (2009b) Morphology and sedimentology of a microtidal, beachrock-infected beach: Vatera Beach, Lesvos, NE Mediterranean. Cont Shelf Res 29(16):1937–1947

    Article  Google Scholar 

  • Vousdoukas MI, Ferreira PM, Almeida LP, Dodet G, Andriolo U, Psaros F, Taborda R, Silva AN, Ruano AE, Ferreira Ó (2011) Performance of intertidal topography video monitoring of a meso-tidal reflective beach in South Portugal. Ocean Dyn. doi:10.1007/s10236-011-0440-5

  • Wright LD, Short AD (1984) Morphodynamic variability of surf zones and beaches: a synthesis. Mar Geol 56(1–4):93–118

    Article  Google Scholar 

  • Xue C (2001) Coastal erosion and management of Majuro Atoll, Marshall Islands. J Coast Res 17(4):909–918

    Google Scholar 

Download references


The authors gratefully acknowledge European Community Seventh Framework Programme funding under the research project MICORE (grant agreement No. 202798). We are also indebted to the Restaurant “Paquete” for allowing us to deploy the cameras on their rooftop and for supplying electric power and space for our equipment. We are also thankful to Dr. Oscar Ferreira for the help and support, to Dr. Rui Taborda for providing the video cameras, and to Dr. Andre Pacheco, Umberto Andriolo, and Fotis Psaros for their contributions in the fieldwork.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Michalis Ioannis Vousdoukas.

Additional information

Responsible Editor: Michel Rixen

This article is part of the Topical Collection on Maritime Rapid Environmental Assessment

Appendix: The graphical user interface timestack processing application

Appendix: The graphical user interface timestack processing application

Application window

The GUI MATLAB application is freely available from the following link:

The program is initiated by the GUI_timestack command though the MATLAB command prompt, and the main window consists of five panels, the options of which are described below:

  • Timestack panel

    The upper panel displaying the timestack, the extracted swash excursion tracks, and the individual peaks expressing the extrema points of each identified sash front

  • Additional plots panel

    Includes (a) a plot showing the beach profile, the R 2, R max, and η tide levels, as well as the limits of the profile section considered for beach-face slope estimation and (b) a plot showing the wave run-up spectra

  • General options panel

    Involves basic settings before the actual timestack processing steps:

    • “Select data path”—setting the path of the input data files

    • “Select file”—selecting a specific data file to process

    • “Start from”—selecting the number of the initial data file to process (valid for the “Select data path” option)

    • “Next”, “Previous”—allow browsing through the data files. Important: All extracted information are discarded

  • Swash tracking panel

    Gives the possibility to the user to enhance check the quality of the extracted data:

    • “Set limit”—the user can reduce the “vertical dimensions” of the active timestack area for image processing by clicking twice with the mouse. It is useful since in zooming on the image section containing the swash motions, the performance of the swash extraction algorithm increases significantly.

    • “Clear”—deletes all the swash tracking results

    • “Restart”—restarts the timestack processing procedure, deleting the existing data for the specific data file

    • “Manual mode”—allows manual corrections on the extracted swash lines; after “Clear,” it allows completely manual identification

  • Export options panel

    Involves actions following the data extraction procedure related to data export:

    • “Clean R_2”—deletes the estimated R 2 value from the data file with the final results

    • “Flag”—is an option to mark bad quality images and export them in a separate “Flagged” directory

    • “Save & continue”—exports the data output file to the “Exports” directory and initiates the processing of the following input data file

    • “Quit”—terminates the program

Import data files

In order to process timestack images using the GUI MATLAB application, the data have to be organized in separate MATLAB structure files named “stack.” Once the data path is set, the program will search and open and contained .mat files so only the timestack files should be included in the data directory. The “stack” structure should include the following variables:


the time stack image nx × nt, where nx expresses the number of grid points along the beach transect considered for timestack generation and nt the number of individual snapshots processed to generate the timestack image

x, z :

cross-shore real-world coordinates and elevation of the beach transect considered for timestack generation


corresponding significant wave height


corresponding peak wave period


corresponding wave direction


corresponding tidal elevation


corresponding date


corresponding time


corresponding MATLAB serial date (one value)


time series of MATLAB serial date corresponding to the acquisition time of the individual snapshots processed to generate the timestack image

Export data files

The data output is included in an “exprt” structure file with the following variables:


time series of the wave run-up elevation


time series of the corresponding time in seconds


estimated R 2 value


estimated R max value


frequency variable of the estimated wave run-up spectra


spectral density variable of the estimated wave run-up spectra


time series of the cross-shore swash excursion position


2% exceedence value of the cross-shore swash excursion position


maximum cross-shore swash excursion position


timestack metadata including the basic data input variables

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Vousdoukas, M.I., Wziatek, D. & Almeida, L.P. Coastal vulnerability assessment based on video wave run-up observations at a mesotidal, steep-sloped beach. Ocean Dynamics 62, 123–137 (2012).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Wave run-up
  • Beach dynamics
  • Swash zone
  • Nearshore waves
  • Video imaging of waves
  • Image processing