FN Archimer Export Format
PT J
TI Influence of morphological changes on suspended sediment dynamics in a macrotidal estuary: diachronic analysis in the Seine Estuary (France) from 1960 to 2010
BT 
AF GRASSO, Florent
   LE HIR, Pierre
AS 1:1;2:1;
FF 1:PDG-ODE-DYNECO-DHYSED;2:PDG-ODE-DYNECO-DHYSED;
C1 IFREMER, DYNECO DHYSED, Ctr Bretagne, CS 10070, F-29280 Plouzane, France.
C2 IFREMER, FRANCE
SI BREST
SE PDG-ODE-DYNECO-DHYSED
IN WOS Ifremer UPR
IF 1.887
TC 33
UR https://archimer.ifremer.fr/doc/00479/59046/65965.pdf
LA English
DT Article
DE ;Estuary deepening and narrowing;Sediment dynamics;Turbidity maximum;Tidal asymmetry;Stratification;Numerical modelling;Morphological changes
AB Estuaries are subject to extensive morphological changes through human activities, such as deepening and narrowing via dredging and channelization. The estuary sediment load, characterised by the estuarine turbidity maximum (ETM), can severely increase in response to channel deepening, shifting the estuary from a natural to hyperturbid state. The main processes driving the estuarine circulation, hydrology and sediment dynamics are relatively well known. However, their relative influence on suspended sediment concentration (SSC), as well as their role in the transition toward hyperturbid estuaries, is still a subject of debate. Therefore, this study aims at investigating the relative contribution of key estuarine drivers (gravitational circulation and tidal pumping mechanisms) on the ETM dynamics under significant estuary morphological changes. In a 3D numerical model of the Seine Estuary (France), three bathymetries from the last 50years (1960, 1975 and 2010) were implemented, characterising the gradual estuary deepening and narrowing. The morphological changes induce an expected tidal amplification in the main channel, associated with a decrease of the tidal duration asymmetry. The salinity front slightly migrates up-estuary and the stratification strengthens, resulting in a higher and upper-estuary SSC distribution. Starting from a dominantly natural system driven by the tidal pumping mechanism in 1960, the contribution of the gravitational circulation strongly increased in the present-day anthropogenically-controlled system. Contrastingly, the maximum ETM mass barely changes with the morphological changes and dredging activities have hardly any influence. Hence, the maximum ETM mass in the Seine Estuary would principally result from the tidal forcing rather than the morphology. 
PY 2019
PD JAN
SO Ocean Dynamics
SN 1616-7341
PU Springer Heidelberg
VL 69
IS 1
UT 000455507500007
BP 83
EP 100
DI 10.1007/s10236-018-1233-x
ID 59046
ER

EF