iScience,
Год журнала:
2024,
Номер
28(1), С. 111681 - 111681
Опубликована: Дек. 25, 2024
The
construction
of
dams
to
intercept
natural
rivers
constitutes
the
most
severe
human
activity
influencing
underlying
surface.
This
study
focuses
on
four
cascade
reservoirs
Lancang
River
and
explores
their
impact
migration
organic
matter
in
sediments.
research
reveals
significant
spatial
variations
total
carbon
(TOC)
nitrogen
concentrations
sediments
reservoirs.
isotopes
indicate
that
terrigenous
is
main
source
TOC
sediments,
contributing
an
average
66.80%.
Endogenous
algal-derived
second
source,
between
14.30%
32.91%.
sources
contributed
from
upstream
are
lowest,
ranging
6.36%
15.33%.
Our
demonstrates
may
significantly
alter
processes
material
river
basin
ecosystem,
particularly
large
reservoir
which
increased
more
endogenous
matter.
Journal of Geophysical Research Oceans,
Год журнала:
2024,
Номер
129(12)
Опубликована: Дек. 1, 2024
Abstract
The
dynamic
behavior
of
particulate
organic
carbon
(POC)
is
crucial
for
understanding
biogeochemical
cycling
in
coastal
and
oceanic
environments.
However,
intense
watershed
human
activities
have
significantly
altered
the
POC
transport
burial
estuary‐coast
continuum.
Here,
we
developed
a
novel
parameterization
scheme
that
incorporates
grain‐size
constraints
to
investigate
dispersal
accumulation
processes
off
Yellow
River
mouth
during
water‐sediment
regulation
(WSRS)
using
three‐dimensional
hydrodynamic
model
(FVCOM).
result
shows
successfully
captures
offshore
sorting
POC,
which
leads
progressive
increase
content
with
dispersion
significant
variations
sediment
deposition
across
different
isobaths.
Rapid
fluctuations
river
discharge
composition
WSRS
stages
noticeable
differences
sedimentation
patterns
POC.
At
Water‐regulation
stage,
distinct
are
observed
distribution
riverine
various
In
contrast,
Sediment‐regulation
these
reduced
due
finer
sediment.
Compared
sediment‐regulation,
plays
role
enhancing
effective
Coarse‐grained
can
form
an
armored
layer
protects
OC
from
disturbance.
Additionally,
increased
runoff
this
stage
promotes
less
energetic
environment
(>10
m
depth).
This
study
provides
valuable
insights
into
dynamics
high‐turbidity
estuarine
It
underscores
importance
employing
comprehensive
modeling
approaches
elucidate
complex
processes.
iScience,
Год журнала:
2024,
Номер
28(1), С. 111681 - 111681
Опубликована: Дек. 25, 2024
The
construction
of
dams
to
intercept
natural
rivers
constitutes
the
most
severe
human
activity
influencing
underlying
surface.
This
study
focuses
on
four
cascade
reservoirs
Lancang
River
and
explores
their
impact
migration
organic
matter
in
sediments.
research
reveals
significant
spatial
variations
total
carbon
(TOC)
nitrogen
concentrations
sediments
reservoirs.
isotopes
indicate
that
terrigenous
is
main
source
TOC
sediments,
contributing
an
average
66.80%.
Endogenous
algal-derived
second
source,
between
14.30%
32.91%.
sources
contributed
from
upstream
are
lowest,
ranging
6.36%
15.33%.
Our
demonstrates
may
significantly
alter
processes
material
river
basin
ecosystem,
particularly
large
reservoir
which
increased
more
endogenous
matter.
