USING SHALLOW NEARSHORE BERM NOURISHMENTS TO ENHANCE BEACH WIDTH

Abstract

Nearshore berms or shoreface nourishments are sandy coastal interventions in which sediment is placed seaward of the land-water interface. These projects rely on natural forces to redistribute sediment in the nearshore zone and mitigate erosion, increase beach width or both. However, there is still limited knowledge on the connection between the morphodynamic development of the nourishment body and the changes to the beach landward to it. Several aspects make it difficult to connect the changes in the sub-aqueous and sub-aerial zones of the cross-shore profile, amongst others the lack of data and the small signal in beach changes with respect to the natural variability. We hypothesize that this obscurity also originates from the deep placement of most nearshore berms, making them mobilized very infrequently. This study examines observations of a unique shallow nearshore berm at New Smyrna (FL) where about 350,000 m3 of sediment dredged from a nearby inlet was deposited in the nearshore zone by moving the end of an outflow pipe along a 400-m section of coast.