FLUORESCENT SANDS FOR MEASUREMENTS OF LONGSHORE TRANSPORT RATES - A CASE-STUDY FROM PRAIA DE FARO IN SOUTHERN PORTUGAL

A field experiment was carried out on a meso-tidal reflective beach to relate longshore sand transport rates to wave measurements in medium- energy conditions (H-rms = 0.6 m; T-m = 6.5 sec; alpha = 20 degrees). Dispersion of fluorescent sand tracers was analyzed using the spatial integration method (SIM). The measured sand transport rate was three t imes larger than the prediction computed using the longshore wave powe r approach, while the K factor was determined empirically as 2.32. The study concluded that there is a need to calibrate bulk longshore tran sport predictors before applying them to steep gradient slopes under p lunging waves.