FN Archimer Export Format
PT J
TI Modelling Fine Sediment Dynamics: Towards a Common Erosion Law for Fine Sand, Mud and Mixtures
BT 
AF MENGUAL, Baptiste
   LE HIR, Pierre
   CAYOCCA, Florence
   GARLAN, Thierry
AS 1:1;2:1;3:2;4:3;
FF 1:PDG-ODE-DYNECO-DHYSED;2:PDG-ODE-DYNECO-DHYSED;3:PDG-ODE;4:;
C1 Ctr Bretagne, IFREMER DYNECO DHYSED, ZI Pointe Diable CS 10070, F-29280 Plouzane, France.
   AAMP, 16 Quai Douane, F-29200 Brest, France.
   SHOM DOPS HOM Sedimentol, 13 Rue Chatellier CS 92803, F-29228 Brest, France.
C2 IFREMER, FRANCE
   AGENCE AIRES MARINES PROTEGEES, FRANCE
   SHOM, FRANCE
SI BREST
SE PDG-ODE-DYNECO-DHYSED
   PDG-ODE
IN WOS Ifremer jusqu'en 2018
   DOAJ
   copubli-france
IF 2.069
TC 28
UR https://archimer.ifremer.fr/doc/00394/50588/51280.pdf
LA English
DT Article
DE ;sand-mud mixture erosion;numerical modelling;non-cohesive to cohesive transition
AB This study describes the building of a common erosion law for fine sand and mud, mixed or not, in the case of a typical continental shelf environment, the Bay of Biscay shelf, characterized by slightly energetic conditions and a seabed mainly composed of fine sand and muddy sediments. A 3D realistic hydro-sedimentary model was used to assess the influence of the erosion law setting on sediment dynamics (turbidity, seabed evolution). A pure sand erosion law was applied when the mud fraction in the surficial sediment was lower than a first critical value, and a pure mud erosion law above a second critical value. Both sand and mud erosion laws are formulated similarly, with different parameters (erodibility parameter, critical shear stress and power of the excess shear stress). Several transition trends (linear or exponential) describing variations in these erosion-related parameters between the two critical mud fractions were tested. Suspended sediment concentrations obtained from simulations were compared to measurements taken on the Bay of Biscay shelf with an acoustic profiler over the entire water column. On the one hand, results show that defining an abrupt exponential transition improves model results regarding measurements. On the other hand, they underline the need to define a first critical mud fraction of 10 to 20%, corresponding to a critical clay content of 3–6%, below which pure sand erosion should be prescribed. Both conclusions agree with results of experimental studies reported in the literature mentioning a drastic change in erosion mode above a critical clay content of 2–10% in the mixture. Results also provide evidence for the importance of considering advection in this kind of validation with in situ observations, which is likely to considerably influence both water column and seabed sediment dynamics. 
PY 2017
PD AUG
SO Water
SN 2073-4441
PU Mdpi Ag
VL 9
IS 8
UT 000408729200011
DI 10.3390/w9080564
ID 50588
ER

EF