Mitigation of Riverbank Erosion Using Controlled Wave-Energy Dissipation Mechanisms

Abstract

Riverbank erosion represents a persistent environmental and socio-economic challenge in river-dominated regions, particularly in large alluvial river systems such as those found in Bangladesh. Continuous bank retreat results in significant land loss, population displacement, and long-term degradation of agricultural productivity. Conventional erosion-control measures—including rigid embankments, revetments, and sandbag-based protection—often provide only short-term stability and are associated with high construction costs, ecological disruption, and erosion transfer to adjacent or downstream river reaches.

This study proposes a mechanically based river-wave energy dissipation framework that mitigates erosion by attenuating hydrodynamic energy within the river channel prior to bank interaction, rather than resisting erosive forces at the bank interface. The proposed system utilizes submerged, horizontally aligned cylindrical rolling mechanisms that interact with incoming surface gravity waves. Through wave–structure interaction, a portion of linear wave momentum is converted into rotational mechanical motion and subsequently dissipated via viscous friction and turbulence within the flow field.

By reducing wave height, orbital velocity, and associated momentum flux, the system effectively lowers boundary shear stress acting on riverbank materials, maintaining applied stresses below critical erosion thresholds. The framework is grounded in established principles of fluid mechanics, wave-energy theory, sediment transport, and river morphology, ensuring consistency with fundamental physical laws and conservation principles.

The proposed approach offers a passive, low-impact, and morphology-preserving alternative to conventional embankment-based erosion control. While further site-specific modeling, experimental validation, and field-scale implementation are required, the conceptual framework demonstrates strong potential for sustainable application in erosion-prone river systems.