Mapping reservoir water quality from Sentinel-2 satellite data based on a new approach of weighted averaging: Application of Bayesian maximum entropy
Scientific Reports,
Journal Year:
2024,
Volume and Issue:
14(1)
Published: July 16, 2024
Abstract
In
regions
like
Oman,
which
are
characterized
by
aridity,
enhancing
the
water
quality
discharged
from
reservoirs
poses
considerable
challenges.
This
predicament
is
notably
pronounced
at
Wadi
Dayqah
Dam
(WDD),
where
meeting
demand
for
ample,
superior
downstream
proves
to
be
a
formidable
task.
Thus,
accurately
estimating
and
mapping
indicators
(WQIs)
paramount
sustainable
planning
of
inland
in
study
area.
Since
traditional
procedures
collect
data
time-consuming,
labor-intensive,
costly,
resources
management
has
shifted
gathering
field
measurement
utilizing
remote
sensing
(RS)
data.
WDD
been
threatened
various
driving
forces
recent
years,
such
as
contamination
different
sources,
sedimentation,
nutrient
runoff,
salinity
intrusion,
temperature
fluctuations,
microbial
contamination.
Therefore,
this
aimed
retrieve
map
WQIs,
namely
dissolved
oxygen
(DO)
chlorophyll-a
(Chl-a)
(WDD)
reservoir
Sentinel-2
(S2)
satellite
using
new
procedure
weighted
averaging,
Bayesian
Maximum
Entropy-based
Fusion
(BMEF).
To
do
so,
outputs
four
Machine
Learning
(ML)
algorithms,
Multilayer
Regression
(MLR),
Random
Forest
(RFR),
Support
Vector
(SVRs),
XGBoost,
were
combined
approach
together,
considering
uncertainty.
Water
samples
254
systematic
plots
obtained
(T),
electrical
conductivity
(EC),
(Chl-a),
pH,
oxidation–reduction
potential
(ORP),
WDD.
The
findings
indicated
that,
throughout
both
training
testing
phases,
BMEF
model
outperformed
individual
machine
learning
models.
Considering
Chl-a,
WQI,
R-squared,
evaluation
indices,
MLR,
SVR,
RFR,
XGBoost
6%,
9%,
2%,
7%,
respectively.
Furthermore,
results
significantly
enhanced
when
best
combination
spectral
bands
was
considered
estimate
specific
WQIs
instead
all
S2
input
variables
ML
algorithms.
Language: Английский
In Situ Hyperspectral Reflectance Sensing for Mixed Water Quality Monitoring: Insights from the RUT Agricultural Irrigation District
Water,
Journal Year:
2025,
Volume and Issue:
17(9), P. 1353 - 1353
Published: April 30, 2025
Water-quality
monitoring
in
agricultural
irrigation
systems
is
challenging
due
to
the
dynamic
and
heterogeneous
nature
of
mixed
water
sources,
which
complicates
traditional
remote
sensing-based
assessment
methods.
Traditional
quality
relies
on
sampling
laboratory
analysis,
can
be
time-consuming,
labor-intensive,
spatially
limited.
In
situ
hyperspectral
reflectance
sensing
(HRS)
presents
a
promising
alternative,
offering
high-resolution,
non-invasive
capabilities.
However,
applying
HRS
mixed-water
environments—where
served-water
effluent,
precipitation,
natural
river
converge—presents
significant
challenges
variability
composition
environmental
conditions.
While
has
been
widely
explored
controlled
or
homogeneous
bodies,
its
application
highly
remains
understudied.
This
study
addresses
this
gap
by
evaluating
relationships
between
data
(450–900
nm)
key
water-quality
parameters—pH,
turbidity,
nitrates,
chlorophyll-a—across
three
campaigns
Colombian
tropical
system.
A
Pearson’s
correlation
analysis
revealed
strongest
spectral
associations
for
with
positive
correlations
at
500
nm
(r
≈
0.76)
700
0.85)
negative
near-infrared
(850
nm,
r
−0.88).
Conversely,
pH
exhibited
weak
diffuse
correlations,
maximum
0.51.
Despite
their
optical
activity,
turbidity
chlorophyll-a
showed
unexpectedly
likely
complexity
matrix.
Random
Forest
regression
identified
regions
each
parameter,
yet
model
performance
was
limited,
R2
values
ranging
from
0.51
(pH)
−1.30
(chlorophyll-a),
RMSE
0.41
1.51,
reflecting
predictive
modeling
temporally
wastewater
systems.
these
challenges,
establishes
baseline
future
applications
complex
highlights
critical
further
investigation.
To
improve
feasibility
assessments,
research
should
focus
enhancing
data-preprocessing
techniques,
integrating
complementary
modalities,
refining
models
better
account
variability.
Language: Английский