Discharge and sand transport in the braided zone of the Zaire estuary
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, meer
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| Trefwoorden |
Motion > Water motion
Transport > Sediment transport
Water bodies > Coastal waters > Coastal landforms > Coastal inlets > Estuaries
Water discharge
Zaire, Congo River
Marien/Kust |
| Abstract |
The sedimentation zone of the maritime reach of the Zaire river located upstream of the canyon is described. The main characteristics of water and sand movements are indicated: stable regime and large discharges ranging from 23000 m3.s-1 to 80000 m3.s-1; low tides at the mouth with an average amplitude of 0.80 m, quickly damped upstream; sand of the bed with grain sizes dropping downstream from 1 mm to 0.2 mm, moving generally as dunes with a speed of 2 m to 10 m per day. The apparition during floods of different and smaller scale bedforms was observed. Measuring and calculation techniques are briefly described. Some results show the influence of geomorphological factors on sand transport phenomena, the erratic variations in time and space of sand transport rates and the influence of tidal movements on these. The role of secondary currents on the distribution of sand transport in and between channels is emphasized. Volumes of water and sand evacuated annually through the braided area are respectively estimated at 1.45 X 1012 and 50 X 106 m3. |
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