Dolphin, T.; Lee, J.; Phillips, R.; Taylor, C.J.L., and Dyer, K., 2016. Velocity of RFID tagged gravel in a nonuniform longshore transport system. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 363–367. Coconut Creek (Florida), ISSN 0749-0208.
Radio-frequency Identification (RFID) tags were embedded into 940 native beach gravel particles and deployed at source on Benhole Beach (Somerset, UK) to develop an understanding of gravel transport along a frontage that is likely to be subjected to construction activity associated with the proposed development of the Hinkley Point C power station. The study lasted for three years, the longest of its kind to be published, and maintained high detection rates (78% on completion) typical of RFID experiments. Tracer distribution through time highlighted non-uniformity in the longshore transport system and that a single average or centroid velocity is meaningless, as it cannot account for alongshore variability – instead methods that can account for alongshore variability in the transport system were needed. Spatial patterns in the density of detected tracer revealed transport pathways. Alongshore variation in tracer velocity was linked to changes in the geomorphology: (i) tracer velocity was slowest over beaches, owing to increased surface roughness, burial and deposition at high elevations; (ii) velocity rose/fell with changes in coastline orientation and wave obliquity; and (iii) the highest velocities were found in areas of exposed smooth rock platform; however small ridges (up to 40 cm) in the rock platform and angular blocks derived from cliff and platform erosion led to significant reductions.