Decadal-scale subaerial beach and dune evolution at Duck, North Carolina

Abstract

Thirty-nine years of high-resolution data from 1981 to 2019 surveyed by the Field Research Facility (FRF) of the US Army Corps of Engineers at Duck, North Carolina, in the United States, were analyzed for temporal and spatial characteristics of beach morphology evolution employing a range of statistical methods. In the study, emphasis was put on the response of the subaerial part of the beach profile to waves and water levels at several different spatial and temporal scales, ranging from weekly to decadal response. The profile data set was analyzed to determine the subaerial beach evolution, including both the influence of cross-shore sediment transport related to storms and the longshore transport affected by the FRF research pier. The analysis showed that adjacent profile lines exhibit similar beach morphology and evolution with high correlation regarding spatial and temporal patterns. The pier has a noticeable influence on the longshore sediment transport leading to erosion downdrift and accretion updrift of the pier; the dune in the FRF region is rather stable and resistant towards storm erosion, requiring combinations of runup height and water level (i.e., runup level) that reaches the dune face; and erosion high up on the subaerial part of the beach, including the dune, occurs on average due to storms with a return period of 5 years.