A New Formula Of The Longshore Sediment Transport Rate For Predicting Long-Term Beach Evolution
A new formula of longshore sediment transport rate for predicts long-term beach evolution is proposed and compared with previous longshore sediment transport rate formulas. The new formula is developed based on interaction of the longshore current and characteristic of sediment assuming that the longshore current due to wave breaking induced the sediment migration. Besides depend on the longshore current, the migration of the sediment also depends on the characteristic of the sediment that is permeability of the sediment. Sediment with high permeability will be easier to move than sediment with low permeability. This new formula here has some clear advantages compared the Inman-Bagnold formula and the two others formula existing. This formula has the smallest error in the simulation and contains a physically based derivation of the sediment permeability dependence and indirectly through the mean longshore current velocity it includes effect of beach profile shape such as slope. In addition, the new formula can be used to estimate beach changes not only due to breaking waves, but also from currents generated by other mechanism such wind and sediment characteristic.
Keywords - Beach Evolution, Breaking Wave, Longshore Sediment Transport, Permeability And Sediment Characteristic.