How does sediment transfer from gravel-bed rivers to beaches affect coastal erosion and beach morphology?
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Sediment transfer from gravel-bed rivers to beaches can have significant impacts on coastal erosion and beach morphology. The addition of sand (particles < 2 mm) to a gravel bed enhances sediment dynamics, affecting the entrainment and transport rate of coarser fractions, near-bed velocities, and bed morphology . Sand infiltration into the gravel matrix is influenced by the shape of the rising limb of the hydrograph, with short time-to-peak floods favoring sand infiltration during the falling limb and long time-to-peak floods resulting in reduced sand infiltration during the rising limb . The quantification of bedload sediment transport in rivers can be predicted based on hydraulic drivers such as cumulative discharge or stream power exceeding the mobilization threshold . Changes in riverine sediment due to human activities and sea-level rise can lead to erosion of deltaic channels, impacting beach morphology and deposition-erosion processes .
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