THE ROLE OF VEGETATION STRUCTURE ON REDUCING DUNE EROSION AND WAVE OVERTOPPING

Dunes provided habitat for wildlife and coastal protection against high water levels during storms (Duran and Moore, 2013). The relationship between dune morphology (i.e., dune crest and toe elevation) and extreme water levels (runup and setup) allows to determine the storm impact regime on barrier islands (Sallenger, 2000). On the other hand, dune vegetation is also important for controlling the morphology and the growth rate of dunes (Ruggiero et al., 2018). Laboratory experiments have been conducted over the past decade to elucidate the role of vegetation in coastal protection. The main challenge while conducting physical model experiments is the scaling between the flow, plants, and the sediments. Laboratory experiments suggest that vegetation density reduced wave erosion (e.g., Silva et al., 2016). However, a recent study suggests that dune vegetation can accelerate foredune erosion during extreme events (Feagin et al., 2023). Here, a laboratory experiment is conducted to investigate the role of different vegetation structure, using four different species, on the reduction of dune erosion and wave overtopping.