Hydrodynamic performance of riprap structures in reef lagoon under extreme wave loading: Insights from porous media simulations.

This article focuses on the numerical modeling of wave propagation and breaking over coral reef topography with artificial riprap structures, using the volume averaged Reynolds averaged Navier–Stokes (VARANS) equations. The study investigates how the location, height, and permeability of riprap affect wave attenuation and water levels in reef flats and lagoons under various wave and tidal conditions. Results indicate that riprap structures reduce wave heights by inducing earlier wave breaking, with higher riprap increasing wave reflection but potentially raising water levels in front of the reef; permeable riprap performs better at low tide and small waves but offers less protection against solitary waves compared to impermeable riprap. The findings provide guidance for optimizing riprap design to balance effective wave dissipation with ecological considerations in coral reef and lagoon coastal protection.