Wave attenuation characteristics of simulated heterogeneous vegetation

Abstract

Vegetated coastal ecosystems often coexist as diverse seascapes, well connected to each other by various biological, chemical and physical processes. It is of interest to study the effect of heterogeneity in vegetation using models of different combinations of submerged, emergent and compound vegetation on wave attenuation and coastal flooding. This article showcases the results of a physical model study conducted with different types of heterogeneous vegetation models in a two-dimensional wave flume, with wave height attenuation expressed in terms of percentage reduction in wave height and the subsequent extent of inundation expressed in terms of wave run-up on the beach. The test runs were carried out with monochromatic waves of height ranging from 0.08 to 0.16 m in water depths of 0.40 and 0.45 m and wave periods of 1.4–2 sec. The experimental results revealed the significant capability of vegetation in attenuating waves to the tune of 72% to 87%, and controlled flooding in terms of run-up of 0.31 to 0.76 times the wave height. However, the compound heterogeneous model proved to be the most efficient in controlling wave height and coastal flooding. © 2020