| abstracts | Numerous measurements imply that longshore sediment transport varies in temporal scales of not only seconds, minutes or even hours, but also days and months, up to years. Such situations stimulate one to analyse and estimate the rate and variability of longshore sediment transport in meso- and long-term time scales.The present analysis evaluates the annual longshore sediment transport in the multibar surf zone. On the basis of field investigations and some assumptions, a simple relationship for the global daily longshore sediment transport as a function of mean wave height was derived. The mean wave height (H) input can be estimated either by computations from daily wind parameters and cross-shore profile shape or directly by measurements.The accuracy of estimation or prediction of daily longshore sediment transport by the proposed method depends on the degree of stationarity of wind field. Given rates and distributions of longshore sediment transport correspond to definite hydrologic-morphodynamic conditions of the coastal zone. The latter encompass the dominance of oblique approach of waves to the shore, multiple breaking of waves, a multi-bar, mildly sloped (β ≈ 1.5%) shore and grain characteristics (D50 ≈ 0.022 cm, (ρs ≈ 2.65 g/cm3) etc.The intensity of sediment movement resulting from the applied procedure can, in some cases, be underestimated with respect to the total real sediment transport rate. This results from the use of empirical relationships derived on the basis of tracer measurements of sediment movement. The bedload is mainly taken into account in such methods. |