This
study
evaluates
the
residence
time
(RT)
and
total
phosphorus
(TP)
in
a
small
hypereutrophic
lake
city
of
Fortaleza,
Brazil.
The
results
indicate
that
RT
predicted
by
complete-mix
model
is
very
similar
(R²
=
0.83)
to
simulated
with
2-D
hydrodynamic
(CE-QUAL-W2).
Simple
power-laws
were
fitted
describe
TP
concentration
at
inlet
as
functions
inflow,
yielding
correlations
R²
0.84
0.70,
respectively.
combination
these
approach
provided
comprehensive
values
measured
outlet
reasonably
well
0.60).
In
addition,
direct
empirical
correlation
between
precipitation
was
also
obtained.
simulations
nearly
periodic
behaviour
TP,
seasonal
variations
being
much
higher
than
interannual
ones.
Finally,
an
application
showed
reduction
99%
input
load
required
reach
100%
compliance
water
quality
standards;
this
could
be
achieved
connecting
residences
sewage
network.
methodology
proposed
research
can
easily
applied
other
lakes
Brazilian
northeast
extended
tropical
regions
around
globe.
Journal of Environmental Management,
Год журнала:
2025,
Номер
384, С. 125538 - 125538
Опубликована: Май 1, 2025
Phosphorus
is
a
limiting
nutrient
for
eutrophication
in
many
lakes
and
reservoirs
across
the
world.
While
most
management
strategies
aim
at
reducing
external
(watershed)
phosphorus
sources,
internal
loading
(IPL)
often
receives
less
attention,
as
it
challenging
to
measure
or
estimate
through
modeling.
Here,
we
present
novel
approach
characterize
dynamics,
leveraging
multi-decadal
monitoring
data
mass-balance
model
developed
within
Bayesian
inference
framework.
The
performs
well
(R2
=
57
%
RMSE
0.032
mg/L
total
phosphorus)
when
applied
Jordan
Lake,
segmented
eutrophic
reservoir
North
Carolina,
USA.
Results
highlight
dominant
increasing
role
of
summers
(0.53
g/m2/month),
contributing
nearly
twice
loading.
We
also
explore
long-term
lake
warming
scenarios
that
intensify
fluxes
both
into
out
sediment
layer,
but
have
little
effect
on
water-column
concentrations.
Additionally,
investigate
dynamics
under
different
interventions.
Our
simulations
demonstrate
potential
IPL
mitigation
(e.g.,
capping,
dredging)
accelerate
sustain
water
quality
improvements,
particularly
paired
with
reductions.
modeling
transferable
similar
waterbodies,
especially
where
there
need
based
largely
data.
It
provides
computationally
efficient
framework
making
long-term,
probabilistic
forecasts
accounting
future
climate,
anthropogenic
impacts,
gradual
accumulation
(or
depletion)
layer.
Sustainability,
Год журнала:
2022,
Номер
14(21), С. 14117 - 14117
Опубликована: Окт. 29, 2022
Small
reservoirs
play
an
important
role
in
providing
water
to
rural
communities.
Increased
construction
of
small
mitigate
the
effects
droughts
leads
a
High-density
Reservoirs
Network
(HdRN)
reservoirs,
which
can
potentially
modify
streamflows
both
dry
and
wet
periods.
However,
there
is
lack
understanding
interannual
behavior
flow
retention
impact
future
increases
number
mainly
for
HdRN
dryland
catchments.
This
research
aims
determine
possible
increase
on
hydrological
networks,
evaluating
annual
flows
generated
at
outlet
watershed
scenarios
with
different
densities
(number
per
area).
The
study
area
was
Conceição
river
catchment
(3347
km2)
semiarid
Brazil.
model
developed
SWAT.
obtained
appropriate
results
daily
streamflows,
values
0.63,
0.81,
0.53%
NSE,
KGE,
PBIAS,
respectively.
current
density
region
estimated
0.068
square
kilometer
(res/km2).
Eight
expansion
were
defined
between
0.1
res/km2
3.0
res/km2.
showed
that
influence
runoff
reduction
mostly
occurs
probability
exceedance
1%
10%
month
very
months
high
peaks
flow.
due
stronger
during
years
(up
30%)
than
8%),
it
tended
consecutive
rain
(from
about
7%
first
year
20%
last
worst
scenario),
may
intensify
period
extended
droughts.
provides
insights
variability
retention,
help
resources
agencies
better
prepare
hydrologic
extremes
(droughts
floods).
Remote Sensing,
Год журнала:
2024,
Номер
16(11), С. 1870 - 1870
Опубликована: Май 24, 2024
It
is
crucial
to
monitor
algal
blooms
in
freshwater
reservoirs
through
an
examination
of
chlorophyll-a
(Chla)
concentrations,
as
they
indicate
the
trophic
condition
these
waterbodies.
Traditional
monitoring
methods,
however,
are
expensive
and
time-consuming.
Addressing
this
hindrance,
we
conducted
a
comprehensive
investigation
using
several
machine
learning
models
for
Chla
modeling.
To
end,
used
situ
collected
water
sample
data
remote
sensing
from
Sentinel-2
satellite,
including
spectral
bands
indices,
large-scale
coverage.
This
approach
allowed
us
conduct
analysis
characterization
concentrations
across
149
Ceará,
semi-arid
region
Brazil.
The
implemented
included
k-nearest
neighbors,
random
forest,
extreme
gradient
boosting,
least
absolute
shrinkage,
group
method
handling
(GMDH);
particular,
GMDH
has
not
been
previously
explored
context.
forward
stepwise
was
determine
best
subset
input
parameters.
Using
70/30
split
training
testing
datasets,
best-performing
model
model,
achieving
R2
0.91,
MAPE
102.34%,
RMSE
20.4
μg/L,
which
were
values
consistent
with
ones
found
literature.
Nevertheless,
predicted
concentration
most
sensitive
red,
green,
near-infrared
bands.
Eutrophication,
a
global
concern,
impacts
water
quality,
ecosystems,
and
human
health.
It’s
crucial
to
monitor
algal
blooms
in
freshwater
reservoirs,
as
they
indicate
the
trophic
condition
of
waterbody
through
Chlorophyll-a
(Chla)
concentration.
Traditional
monitoring
methods,
however,
are
expen-sive
time-consuming.
Addressing
this
hindrance,
we
developed
models
using
remotely
sensed
data
from
Sentinel-2
satellite
for
large-scale
coverage,
including
its
bands
spectral
indexes,
estimate
Chla
concentration
on
149
reservoirs
Ceará,
Brazil.
Several
machine
learning
were
trained
tested,
k-nearest
neighbours,
random
forests,
extreme
gradient
boosting,
least
absolute
shrinkage,
group
method
handling
(GMDH),
sup-port
vector
models.
A
stepwise
approach
determined
best
subset
input
parameters.
Using
70/30
split
training
testing
datasets,
best-performing
model
was
GMDH,
achieving
an
R2
0.91,
MAPE
102.34%,
RMSE
20.38
g/L,
which
values
consistent
with
ones
found
literature.
Nevertheless,
predicted
most
sensitive
red,
green,
near
infra-red
bands.
Desalination and Water Treatment,
Год журнала:
2024,
Номер
317, С. 100200 - 100200
Опубликована: Янв. 1, 2024
The
protection
of
water
quality
in
reservoirs,
particularly
those
designated
for
supply,
has
garnered
increasing
attention
environmental
management
purposes.
In
this
paper,
the
Shuangxikou
Reservoir
Yuyao
was
chosen
as
a
case
study.
pollutant
load
at
various
points
within
reservoir
analyzed
and
its
eutrophication
level
evaluated
through
combination
site
surveys
regular
monitoring.
Additionally,
model
trial
algorithm
utilized
to
investigate
environment
capacity
concerning
key
indicators
such
COD,
NH3-N,
TN,
TP
Reservoir.
results
indicated
that
nutrient
fell
mid-trophic
range,
with
being
superior
central
region
compared
other
areas.
However,
when
target
Class
II
surface
mandated
by
functional
zoning,
current
TN
content
exceeds
acceptable
levels.
Consequently,
targeted
measures
are
imperative
enhance
reservoir.