Sustainability,
Journal Year:
2023,
Volume and Issue:
15(24), P. 16591 - 16591
Published: Dec. 6, 2023
Dissolved
inorganic
nutrients
are
pivotal
in
maintaining
the
material
and
energy
balance
of
marine
ecosystems,
impacting
survival
dynamic
succession
organisms.
To
gain
a
deeper
understanding
source
sink
characteristics
dissolved
bays
affected
by
human
activities
to
elucidate
processes
involving
filter-feeding
shellfish
relation
these
nutrients,
this
study
investigated
dynamics
Dapeng
Cove
sea
area
Shenzhen.
Over
past
decade,
significant
change
N/P
ratio
within
survey
has
been
observed,
suggesting
shift
nutrient
limitation
from
nitrogen
phosphorus
or
phosphorus–silicon
limitation.
This
induced
ratio,
along
with
Si/N
Si/P
ratios,
may
facilitate
growth
cyanobacteria
and,
subsequently,
alter
proportions
diatoms,
dinoflagellates,
cyanobacteria.
Seasonal
fluctuations
disturbance
intensity
precipitation
determine
seasonal
spatial
distribution
bay,
thereby
influencing
bay
ecosystem
metabolism.
The
Land–Ocean
Interactions
Coastal
Zone
(LOICZ)
model
analysis
revealed
that
represents
major
phosphate
spring,
summer,
autumn,
while
acting
as
for
winter.
Furthermore,
rivers
groundwater
represent
primary
sources
bay.
exhibits
an
annual
net
metabolic
rate
7.06
mmol
C/m2/d,
denitrification
dominating
cycle
at
12.65
C/m2/d.
Overall,
displays
production
exceeding
respiration,
classifying
it
autotrophic
system.
Additionally,
is
predominantly
driven
denitrification.
also
impact
oyster
proliferation
on
physical
chemical
factors
surveyed
relatively
weaker
than
surface
runoff
inputs.
Water Practice & Technology,
Journal Year:
2022,
Volume and Issue:
17(5), P. 1230 - 1252
Published: May 1, 2022
Abstract
The
Krishnagiri
reservoir
is
the
main
source
of
irrigation
in
Tamil
Nadu,
India.
It
has
been
reported
to
be
hypereutrophic
for
over
a
decade
with
sediment
and
nutrient
load
sources
responsible
degradation
water
quality.
Remotely
sensed
satellite
imagery
analysis
plays
significant
role
assessing
quality
developing
management
strategy
reservoirs.
present
study
an
attempt
demonstrate
improvement
chlorophyll-a
(chl-a)
estimation
by
integrating
remote
sensing
in-situ
measurements.
Multiple
regression
equations
were
developed
reflectance
Green,
Red,
NIR
SWIR1
bands
Operational
Land
Imager
(OLI)
sensor
Landsat
8
yielded
coefficient
determination
as
0.812,
total
dissolved
solids
(TDS)
0.945
electrical
conductivity
(EC)
0.960
respectively.
model
was
further
utilised
forecast
chl-a
EC
through
seasonal
auto
regressive
integrated
moving
average
(SARIMA)
model.
found
that
prediction
showed
continued
significantly
changed
from
class
C3
(high
salinity)
C4
(very
high
salinity).
These
results
are
alarming
immediate
reduction
external
catchment
effective
watershed
programs
should
implemented.
Water,
Journal Year:
2024,
Volume and Issue:
16(21), P. 3090 - 3090
Published: Oct. 29, 2024
Predicting
the
dissolved
oxygen
concentration
and
identifying
its
driving
factors
are
essential
for
improved
prevention
management
of
anoxia
in
estuaries.
However,
complex
hydrodynamic
conditions
limitations
traditional
methods
result
challenges
identification
low
(DO)
phenomenon.
The
objective
our
study
is
to
develop
a
robust
deep
learning
model
using
four-year
situ
data
collected
from
an
automatic
water
quality
monitoring
station
(AWQMS)
estuary,
accurate
quantification
influencing
DO
levels.
Mitigations
hypoxia
were
observed
during
initial
two
years,
but
subsequent
decline
concentrations
was
witnessed
recently.
periodicity
Pearl
River
Estuary
reduced
with
increase
hypoxic
intensity.
Maximal
information
coefficient
(MIC)
extreme
gradient
boosting
(XGBoost)
employed
determine
significance
input
variables,
which
subsequently
validated
by
long-
short-term
memory
networks
(LSTMs).
contributing
problem
shown
as
temperature,
pH,
conductivity,
NH4+-N
concentrations.
Notably,
evaluation
index
values
hybrid
MAPE
=
0.0887
R2
0.9208,
have
been
compared
LSTM
about
99.34%
reduction
16.56%
improvement,
indicating
that
MixUp-LSTM
capable
effectively
capturing
nonlinear
relationships
between
other
indicators.
Based
on
existing
literature,
three
statistical
four
machine
models
also
performed
compare
proposed
model,
outperformed
terms
prediction
accuracy
robustness.
Overall,
successful
deoxygenation
phenomenon
would
important
implications
governance
regulation
Journal of Hydrology Regional Studies,
Journal Year:
2023,
Volume and Issue:
50, P. 101554 - 101554
Published: Oct. 20, 2023
Shenzhen
Bay
(SZB)
in
the
east
Pearl
River
Estuary,
China
Either
NO3−
or
NH4+
is
dominant
component
of
dissolved
inorganic
nitrogen
(DIN)
most
estuarine
waters,
but
few
studies
focused
on
mechanisms
ongoing
DIN
transformations
under
various
hydrologic
regimes.
This
analysis
spans
31
years
changes
and
involves
numerical
simulations
to
identify
roles
driving
factors
including
runoff
biogeochemical
actions.
These
new
insights
into
change
from
coupling
hydrodynamic
processes
would
help
boost
effective
mitigation
measures
deal
with
nitrate
accumulation
thereby
supporting
integrated
land-ocean
nutrient
management.
The
SZB
was
found
transition
between
1990
2020.
Particularly
-upper
bay,
there
an
unexpected
increase
mean
concentration
fraction
DIN,
rising
19.5%
(1990‐2017)
65.5%
(2018‐2020).
can
be
partially
attributed
reduced
inputs.
Both
tidal
current
transport
NO3−downstream,
high
background
levels
lower
bay
contributed
sustaining
upper
through
ebb
flow.
Biogeochemical
actions
further
strengthened
decline
rise
NO3−.
Even
scenarios
without
terrestrial
source
inputs,
simulated
continued
reduce
throughout
while
increasing
concentrations
middle
bay.
