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distributary infill
distributary infill
t
0
MWL
t
3
delta front deposition
t
12
delta front deposition
t
23
t
34
y
1
y
2
t
45
infill proximal delta
y
2
y
1
water level
set-up
former distributary
former distributary
vol. %
sand
1
0.8
.1 m
50 m
0.6
model sediment
layer resolution
0.4
t
45
z
1 m
t
0
0.2
t
0
Fig. 5.
Morphodynamics and associated stratal response of a cross-section in the proximal delta (see Fig. 2 for location)
under sole wave forcing (Base case scenario). Subscripts of t refer to simulated number of months. The red arrow indicates
the direction of the waves. The cross section inset shows in detail the deposition at a main distributary channel (location
indicated at t
45
cross-section to the left).
(Fig. 3). Suspended load transport is much higher
than bed load transport for both sediment frac-
tions. The bed load transport consists mainly of
sand but sand transport along the delta front is
only marginal. Fig. 5 shows the morphologic and
stratigraphic adjustment in time (t
0
to t
45
) of a cross
section in detail illustrating both the significant
sand deposition along the flank of the delta as well
as the infill of distributary channels by silt. Note
the large-scale lateral coarsening associated with
the retrograding delta front and the infill of delta
plain distributaries by fines. After the final time
step, even the most proximal distributary is filled
with fines by waning wave-induced currents.
Consequently, some distributaries that were formerly
incised into the substrate are preserved.
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