Under the pressures of climate change and intensifying human activities, coral reefs face the dual imperative of ecological restoration and enhanced resilience to wave action. While eco-friendly artificial reef structures show promise for wave attenuation and cost-effectiveness, their engineering application remains constrained by a limited systematic understanding of their effects on wave dynamics over coral reefs. This knowledge gap impedes the scientifically informed deployment of such structures. To address this, the present study investigates the hydrodynamic influence of porous hemispherical artificial reef groups (PHARG) on wave transformation over a coral reef profile using combined physical experiment and numerical simulations (OpenFOAM). Experimental results demonstrate that PHARG induce complex wave–structure interactions, leading to a measurable reduction in time-mean wave height in their vicinity. The structures also exert considerable drag on wave-induced flows, effectively attenuating wave setup and shore-directed current intensity on the reef flat. Furthermore, the presence of PHARG promotes earlier wave breaking, thereby reducing breaking wave height in most scenarios. Numerical simulations complement these findings by revealing strong upwelling around the reef units and the generation of complex vortex structures through wave–reef interaction. These hydrodynamic features are likely to create favorable micro-habitats for epibenthic organisms. This work aims to provide a scientific basis for optimizing the layout and application of artificial ecological reefs in coral reef environments.
Qu et al. (2026) studied this question.