Over the past century, human activities have greatly altered the geomorphology of the multi-outlet system at the Pearl River Estuary bayhead. Combining sediment cores, seismic data, bathymetric records and morphodynamic simulations, this paper explores sedimentary and geomorphic variations of the Hongqili subaqueous delta under intensive human interference. Grain-size analysis via K-means clustering distinguishes three sedimentary facies, consistent with distributions of residual currents and suspended sediments. Driven by converging currents from adjacent outlets, its deposits appear asymmetric and elongated, differing from those of single-outlet deltas, with the delta front offshore boundary at the ~5 m isobath. A three-stage evolution model is established considering anthropogenic impacts: natural southward progradation in Stage I, eastward shift of currents, sediment transport and depocenter due to channel incision and reclamation in Stage II, and dominant eastward migration of the depocenter in Stage III. This reveals that coastal reclamation profoundly reshapes estuarine delta sediment dispersal, and the model can be adapted for similar multi-outlet tidal deltas.
 

暂无