Changing water and sediment dynamics in the Pearl River network and consequences on water and sediment regimes in the Lingdingyang estuary

A 2-dimensional model is used to simulate the hydrodynamic and sediment fields of the Lingdingyang estuary(LDYE) in flood seasons of 1978 and 1999.The results show the hydrodynamics and suspended sediment dynamics have been largely altered.The hydrodynamics of the LDYE is strengthened in flood seasons,with the alterations varying in different areas.The flood and ebb tidal velocities increase by 0.10 m/s in the west and east channels and the middle shoal.As a whole,the sediment concentration of the LDYE increases by 0.02-0.05 kg/m³.The high concentration area is enlarged,and the isocline of 0.10 kg/m³ extends from the west channel to the east channel,indicating that the influence of fluvial sediment has enhanced markedly.