Abstract
A method is described for the evaluation of large scale (km) changes in the intertidal beach morphology using video images. Data is presented from an Argus station located at a strongly macrotidal beach (maximum tidal range ≈7.5 m) at Perranporth, Cornwall, UK. Shoreline positions are digitized from spatial differentials of the rectified time-exposure images recorded at equal increments in the predicted tidal height. The horizontal (x-y) coordinates of the shoreline are obtained directly from these images and the vertical coordinate (z) is taken from an accurate tidal model for the area. Corrections for the vertical offset of the video survey relative to a measured beach profile which arise due wave setup, swash and atmospheric pressure variations are removed using a small amount of ground truth survey data. Comparisons between the video and a total station survey show an excellent agreement in the estimated 3-dimensional intertidal morphology with standard errors of less than 11 cm. The method shows great promise for quantifying large scale (in this case 1000 m by 500 m), long term (weeks, months, years) changes in the intertidal beach morphology.
| Original language | English |
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| Pages (from-to) | 385-394 |
| Number of pages | 0 |
| Journal | Coastal Dynamics - Proceedings of the International Conference |
| Volume | 0 |
| Issue number | 0 |
| Publication status | Published - 1 Dec 1997 |