Image processing and laser measurements for determination of the erosion and deposition of fine sediments by a gravity current

This paper reports a high-resolution, non-intrusive, low-cost technique to measure volumes of erosion and deposition of fine sediments. The combination of two techniques, photography and laser scanning, gives the advantage of simultaneous quantitative estimation of erosion and deposition and visualization of deposition patterns. The use of this technique is tested for recording the geomorphological changes induced by the passage of a gravity current over a erodible bed. Good results are obtained, indicating that the combination of both methods can be considered for a range of multi-purpose applications in which the measurement of erosion and deposition is required. Finally, results for the deposition patterns, which are created by the highly turbulent flow field of the gravity currents, are discussed, showing the potential of these techniques for studying anisotropic bed structures. (paper)