Temporal variations in concentration and transport of suspended sediments in a channel-flat system in the Ems-Dollard estuary

Observations of suspended sediment concentration (SSC), currents and water levels above a tidal flat and in a nearby channel in the Dollard basin in t he Ems-Dollard estuary are used to derive general characteristics of variat ions in SSC and the transport of suspended sediments in a channel-hat syste m in the Wadden Sea. Tidal currents show a strong ebb dominance which is ca used by the large intertidal flats in the Dollard basin. Intra-tidal variat ions in SSC are limited by the availability of fine-grained sediments resul ting in similar concentrations during ebb and flood in the channel. Wind ev ents influence the SSC above the flat much more than in the channel. The ne t transport of sediments above the intertidal hat appears to be highly vari able. Under fair weather conditions there is a relatively small net transpo rt towards the higher levels of the tidal flat. When the wind speed increas es the net transport increases drastically. However, the direction of the n et transport of sediments is very variable in contrast to the net. transpor t of water. (C) 2000 Elsevier Science Ltd All rights reserved.