Controlling factors of rhythmic sedimentation processes on an intertidal estuarine mudflat — Role of the turbidity maximum in the macrotidal Seine estuary, France. Deloffre, J.; Lafite, R.; Lesueur, P.; Verney, R.; Lesourd, S.; Cuvilliez, A.; and Taylor, J. 235(1):151–164. Number: 1
Controlling factors of rhythmic sedimentation processes on an intertidal estuarine mudflat — Role of the turbidity maximum in the macrotidal Seine estuary, France [link]Paper  doi  abstract   bibtex   
The aim of this study is to analyse and to quantify the fine particles transfer (i.e.\textless63 μm) in the marine part of the man-altered macrotidal Seine estuary (France) by (i) an analysis of a two year time-series of altimeter data, which reveals the bed elevation variations on an intertidal mudflatd located at the Seine mouth and (ii) measurements of the concentration of suspended particulate matter (SPM) contained within the turbidity maximum (TM). The results of this analysis reveal that sedimentation on the mudflat is mainly controlled by the dynamics of the TM such that during the largest spring tides (i.e. tidal ranges \textgreater7.1 m). Then, deposition of SPM from the turbidity maximum becomes important, allowing fine particles to settle on the mudflat, where the current velocities are low (\textless0.4 m s−1). On tides of lower range (\textless7.1 m) bed elevation levels suggest that erosion of the mudflat surface dominates, however dewatering processes also occur in the soft mud deposits resulting in compaction. During periods of wave activity and periods of increasing river discharge, the mudflat surface experiences rapid erosion. These periods of erosion (sudden or progressive) imply a transfer of fine-grained material from the mudflat surface back into the TM. The long term (∼22 months), high frequency (1 measurement every 10 min) and high resolution (0.6 mm) dataset obtained from the altimeter allows quantification of the volume of material exchanged between the intertidal area and the estuarine standing stock of SPM. The maximum of deposition on the studied mudflat during the study was of 27 cm, with highest deposition occurring after the periods of highest river flow and implying that between 25 and 40% of the maximum estimated mass of SPM held within the estuarine TM (300,000–500,000 T) had been temporarily deposited on the mudflat. Likewise following periods of resuspension by wave activity, bed elevations reduced by an order of ∼1 cm, suggesting a release of between 1–1.5% of the TM load from the mudflat back into suspension. The study shows that lateral exchanges of sediment between the intertidal reaches of the estuary and the water column are an important part of the sediment budget, and that the supply of sediment available for deposition (i.e. the TM) has a causal relationship with sedimentation rates experienced by intertidal mudflats.
@article{deloffre_controlling_2006,
	title = {Controlling factors of rhythmic sedimentation processes on an intertidal estuarine mudflat — Role of the turbidity maximum in the macrotidal Seine estuary, France},
	volume = {235},
	issn = {0025-3227},
	url = {http://www.sciencedirect.com/science/article/pii/S0025322706002647},
	doi = {10.1016/j.margeo.2006.10.011},
	series = {Proceedings of the 6th International Congress on Tidal Sedimentology (Tidalites 2004)},
	abstract = {The aim of this study is to analyse and to quantify the fine particles transfer (i.e.{\textless}63 μm) in the marine part of the man-altered macrotidal Seine estuary (France) by (i) an analysis of a two year time-series of altimeter data, which reveals the bed elevation variations on an intertidal mudflatd located at the Seine mouth and (ii) measurements of the concentration of suspended particulate matter ({SPM}) contained within the turbidity maximum ({TM}). The results of this analysis reveal that sedimentation on the mudflat is mainly controlled by the dynamics of the {TM} such that during the largest spring tides (i.e. tidal ranges {\textgreater}7.1 m). Then, deposition of {SPM} from the turbidity maximum becomes important, allowing fine particles to settle on the mudflat, where the current velocities are low ({\textless}0.4 m s−1). On tides of lower range ({\textless}7.1 m) bed elevation levels suggest that erosion of the mudflat surface dominates, however dewatering processes also occur in the soft mud deposits resulting in compaction. During periods of wave activity and periods of increasing river discharge, the mudflat surface experiences rapid erosion. These periods of erosion (sudden or progressive) imply a transfer of fine-grained material from the mudflat surface back into the {TM}. The long term (∼22 months), high frequency (1 measurement every 10 min) and high resolution (0.6 mm) dataset obtained from the altimeter allows quantification of the volume of material exchanged between the intertidal area and the estuarine standing stock of {SPM}. The maximum of deposition on the studied mudflat during the study was of 27 cm, with highest deposition occurring after the periods of highest river flow and implying that between 25 and 40\% of the maximum estimated mass of {SPM} held within the estuarine {TM} (300,000–500,000 T) had been temporarily deposited on the mudflat. Likewise following periods of resuspension by wave activity, bed elevations reduced by an order of ∼1 cm, suggesting a release of between 1–1.5\% of the {TM} load from the mudflat back into suspension. The study shows that lateral exchanges of sediment between the intertidal reaches of the estuary and the water column are an important part of the sediment budget, and that the supply of sediment available for deposition (i.e. the {TM}) has a causal relationship with sedimentation rates experienced by intertidal mudflats.},
	pages = {151--164},
	number = {1},
	journaltitle = {Marine Geology},
	shortjournal = {Marine Geology},
	author = {Deloffre, J. and Lafite, R. and Lesueur, P. and Verney, R. and Lesourd, S. and Cuvilliez, A. and Taylor, J.},
	urldate = {2019-04-15},
	date = {2006-12-20},
	note = {Number: 1},
	keywords = {Seine estuary, intertidal mudflat, river flow, tidal cycles, turbidity maximum, waves}
}
Downloads: 0