The present paper reports the results obtained in a field experiment carried out on a medium-energy, mesotidal, reflective beach on Culatra Island (southern Portugal). Simultaneous time-series measurements of waves, currents and sediment concentration were taken during 1.5 tidal cycles using a pressure transducer, two bidirectional electromagnetic current-meters and three optical backscatter sensors. Measurements of suspended sediment transport were compared with fluorescent sand tracers. Total longshore sediment fluxes measured with optical techniques and sand tracers were found to give similar results, if their major limitations are considered. The present experiment confirms the different sedimentary behaviours of steep reflective beaches with plunging breakers, as opposed to the low-gradient beaches with spilling breakers where most previous studies have been performed, and supports the idea that one of the major limitations of longshore sediment transport models is their lack of d...
Measurements of suspended sediment transport on a reflective meso-tidal beach in southern Portugal
CIAVOLA, Paolo;
1999
Abstract
The present paper reports the results obtained in a field experiment carried out on a medium-energy, mesotidal, reflective beach on Culatra Island (southern Portugal). Simultaneous time-series measurements of waves, currents and sediment concentration were taken during 1.5 tidal cycles using a pressure transducer, two bidirectional electromagnetic current-meters and three optical backscatter sensors. Measurements of suspended sediment transport were compared with fluorescent sand tracers. Total longshore sediment fluxes measured with optical techniques and sand tracers were found to give similar results, if their major limitations are considered. The present experiment confirms the different sedimentary behaviours of steep reflective beaches with plunging breakers, as opposed to the low-gradient beaches with spilling breakers where most previous studies have been performed, and supports the idea that one of the major limitations of longshore sediment transport models is their lack of d...I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
