EXPERIMENTAL FLUME SIMULATION OF SHOREFACE NOURISHMENTS UNDER STORM CONDITIONS

This study focuses on barred beach shoreface nourishments physically simulated in a wave flume. The attack of a schematic storm on three different nourishments is analysed. The apex and waning storm phases lead respectively to off-shore and on-shore sediment transport. The trough and outer bar nourishments are feeding the bar and increase wave dissipation off-shore. The bar acts as a wave filter and reduces shore erosion (lee effect). In contrast, nourishment in the inner zone leads mostly to shore feeding and beach face reconstruction (feeder effect). Along the successive nourishments, the upper beach face is clearly steepening and on-shore sediment transport is reduced during moderate wave climates. The surface sedimentological analysis reveals marked variations. Coarser sediments are sorted on the bar and the upper beach face. These locations correspond to large wave dissipation zones during the storm apex.