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Evidence of dynamics reversal in tropical estuaries, geomorphological and sedimentological consequences (Salum and Casamance Rivers, Senegal)
Author(s) -
BARUSSEAU J. P.,
DIOP E. H. S.,
SAOS J. L.
Publication year - 1985
Publication title -
sedimentology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.494
H-Index - 108
eISSN - 1365-3091
pISSN - 0037-0746
DOI - 10.1111/j.1365-3091.1985.tb00469.x
Subject(s) - estuary , geology , mangrove , hydrology (agriculture) , oceanography , shoal , salinity , salt pan , tidal irrigation , geomorphology , paleontology , ecology , geotechnical engineering , biology
South Dakar Senegambian estuaries are subject to an unusual hydrodynamical regime caused by weak or absent run‐off. In the Salum delta, each distributary lacks fresh water during most of the year. Only the tidal flows are responsible for geomorphological and sedimentological effects. The current distribution shows a net discharge upstream due to the extensive evaporation and evapotranspiration in mangrove swamps and tidal flats. Consequently the salinity is always higher towards the river than near the sea. A high salinity bottom layer suggests the occurrence of a supersaline wedge of reverse sense to the salt wedge of a normal estuary. Such an inverse pattern is similarly displayed by sedimentological features (double upstream turned spits) and by the external location of the turbidity maximum. A coherent reverse estuary model is suggested from our field observations.