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Please use this identifier to cite or link to this item:
http://hdl.handle.net/1834/1459
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| Title: | Sand barrier development in the bight of Benin, West Africa |
| Authors: | Blivi, A.B.
Anthony, E.J.
Oyédé, L.M. |
| ASFA Terms: | Sand banks |
| Issue Date: | 2002 |
| Publisher: | Elsevier |
| Citation: | Ocean and coastal management, 45. p. 185-200 |
| Abstract: | The morphology, sedimentary facies, stratigraphy and development history of re-entrants
and sand barriers in Togo and Benin (West Africa) have been analysed from boreholes and
field data, and available radiocarbon dates. Re-entrant deposits range from basal Late
Pleistocene fluviatile sands into Holocene estuarine and fluvio-deltaic sands. As sea level
stabilized between 6000 and 5500 B.P., the "compartmented" coast associated with these reentrants
favoured a polycellular longshore drift system. As the latter became infilled
throughout the bight of Benin between 6000 and 4000 B.P., the littoral drift system evolved
into a unicellular system fed by the Volta delta in Ghana, which has been the major sand
source for an almost 300 kin long outer harrier. In spite of the massive and consistent volume
of sand drifting eastward (1.2-1.5 x 10'6 m³/yr),progradation slowed down or ceased as
equilibrium was achieved between coastal/shoreface geometry and the hydrodynamic regime,
resulting in a balance between incoming and outgoing sand, and the downdrift migration of
the accumulation sector towards Nigeria. This situation was probably achieved around 1500
to 2500 years ago in Benin, but apparently occurred much earlier in the updrift sector in Togo.
This stability has been perturbed by the construction of deepwater ports in 1962 in Cotonon
and 1967 in Lome leading to segmentation of the unidirectional drift and spectacular
progradation and erosion, respectively, updrift and downdrift of breakwaters. |
| URI: | http://hdl.handle.net/1834/1459 |
| Related document: | http://dx.doi.org/10.1016/S0964-5691(02)00054-6 |
| ISSN: | 0964-5691 |
| Appears in Collections: | Publications et notes réunies sur l'environnement marin et cotier
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