Review by David Huntley
This is an important article, covering what are probably the most successful applications of the ARGUS technique to date. Some comments would benefit from a clearer explanation, particularly for the general reader, and the references could be updated and made more accessible.
In the introduction, Coastal State Indicators (CSI) are mentioned but not defined. Davidson et al. (2007) provide a definition as, “A reduced set of issue-related parameters that can simply, adequately and quantitatively describe the dynamic-state and evolutionary trends of a coastal system”. They cite examples of CSI for coastal protection, beach recreation planning and navigation, all described in more detail in the Coastview Special Issue of the journal Coastal Engineering (vol. 54, issues 6-7).
The introduction also suggests that future applications might involve monitoring visitor numbers at the beach; this has already been demonstrated by Jiménez et al. (2007). The claim that a future application of ARGUS might lead to the ‘prediction of rip currents’ is somewhat optimistic. It may be that ARGUS can help identify conditions favourable to the development of rip currents but precise prediction of their location and strength seems at best a long way off.
Under ‘Intertidal morphological changes at a nourished beach’, the sentence referring to ‘the mean vertical offset’ might require clarification for the general reader. The work described comes from Aaarninkhof et al. (2003) (not in the article reference list despite earlier citation in the text). It refers to the mean difference between image-based and DGPS surveyed shoreline elevations over the surveyed region and corresponds to a 6m mean horizontal offset.
More accessible and recent references for the measurement of surf zone bathymetry are Aarninkhof et al. (2005a and b). An appropriate reference for the Beach Wizard technique is van Dongeren et al. (2008).
It is a pity that the labels in figure 1 are hard to read. The continuous lines in figure 2 are not explained; they appear to show the accumulated change of beach volume over the period shown.
Aarninkhof, S.G.J., Turner, I.L., Dronkers, T.D.T., Caljouw, M. and Nipius, L. (2003).A video-technique for mapping intertidal beach bathymetry. Coastal Engineering, 49, 275-289.
Aarninkhof, S.G.J., Ruessink, B.G. and Roelvink, J.A. (2005a). Nearshore subtidal bathymetry from time-exposure video images. Journal of Geophysical Research, 110, C06011, doi:10.1029/2004JC002791.
Aarninkhof, S.G.A., K.M. Wijnberg, J.A. Roelvink and A.J.H.M. Reniers (2005b), 2DH-Quantication of surf zone bathymetry from video, Proc. Coastal Dynamics ’05.
Davidson, M., van Koningsveld, M., de Kruif, A., Rawson, J., Holman, R., Lamberti, A., Medina, R., Kroon, A. and Aaarninkhof, S. (2007). The CoastView project: Developing video-derived Coastal State Indicators in support of coastal zone management. Coastal Engineering, 54 (6–7), 463–475.
Jiménez, J. A.. Osorio, A. , Marino-Tapia, I., Davidson, M., Medina R., Kroon, A., Archetti, A., Ciavola, P., Aarnikhof, S.G.J. (2007). Beach recreation planning using video-derived coastal state indicators, Coastal Engineering, 54 (6-7), 507-521
van Dongeren, A. Plant, N. Cohen, A. Roelvink, D. Haller, M.C. Catalán, P.(2008). Beach Wizard: Nearshore bathymetry estimation through assimilation of model computations and remote observations. Coastal Engineering, 55 (12), 1016-1027