Presentation of problem: The movement of sediment parallel to the coast by waves and currents is known as longshore sediment transport or littoral transport. Throughout the years, researchers have found that knowledge of longshore sediment transport is important in connection with coastal engineering design, such as construction of breakwaters at harbour entrances, dredging of navigation channels, and improving beaches. During the last three decades, a number of different longshore transport formulas have been proposed. These formulas were based on different approaches, such as the energetic or energy flux approach, the shear stress or modified steady flow approach, as well as others.
Objectives: The main objectives of this study are:
(a) to develop a formula for the total longshore sediment transport
(b) to evaluate the newly developed formula for the longshore sediment transport by comparison with an extensive, highquality field and laboratory data base
(c) to determine values on the empirical coefficient appearing in the new formula.
Procedure: This study was conducted as follows:
(a) literature on longshore sediment transport was reviewed
(b) a formula for the longshore sediment transport was developed based on the formulation proposed by Larson and Bayram (2005)
(c) an extensive data base on longshore sediment transport rates was compiled from the literature, encompassing both laboratory and field data 3
(d) values on an empirical coefficient appearing in the new formula were evaluate and validated.
Conclusions: In general, based on the calculation results, the newly developed formula yielded overall good predictions. The pattern in the graph which compares measured and calculated transport rates for all data sets is similar, although a few points that are located far away from the main group of points. The calculated empirical coefficient is in the range between 0.00018 and 0.0052, whereas the calculated standard deviation ranged from 0.0001 to 0.0024. It is likely that some additional factors influence the value of the empirical coefficient and an analysis was performed to relate the coefficient value to various quantities, such as fall velocity, deep water wave height, wavelength, grain size, and wave period. In conclusion, the objectives in this repo...
