CHARACTERISTICS AND TRANSPORT TREND OF SURFACE SEDIMENTS IN INNER LINGDINGYANG FIRTH OF THE PEARL RIVER ESTUARY

The characteristics of surface sediments are studied with the 158 bottom samples taken from the inner Lingdingyang Firth of the Pearl River Estuary.Sediment transport trends are identified by the GSTA model.The results indicate that there are six types of bed deposits in the inner Lingdingyang Firth,with clayey silt being the dominant.The sediment transport pattern in the inner Lingdingyang Firth is complex.Regarding the sediment migration trend,the firth could be divided into three subareas.In the subarea I,or in the east part of the firth,sediments move from the east to the west.In the subarea II,sediments move in a pattern from northeast to southwest due to the effect of strong reciprocating flow and deep brine water wedge caused by the Coriolis force.In the subarea III from the Hengmen Gate to the Jinxinmen Gate,sediment move from distributaries to the costal beaches.Around the Qiaodao Isle,however,sediments move in a clockwise pattern driven by the local circulation.