Hydrological Processes,
Год журнала:
2023,
Номер
37(9)
Опубликована: Авг. 31, 2023
Abstract
Excess
nitrate
and
sediment,
mobilized
by
precipitation
events
transported
into
surface
waters,
is
a
global
water
quality
challenge.
Recent
advances
in
high‐frequency
situ
monitoring
sensors
have
created
opportunities
to
investigate
constituent
concentration
dynamics
during
short‐term
hydrological
changes.
In
this
study,
we
characterized
the
event‐scale
variability
of
()
turbidity
(a
surrogate
for
sediment
transport)
two
large
agricultural
watersheds
Upper
Mississippi
River
Basin
using
hysteresis
loop
characteristics
determine
sources
dominant
transport
mechanisms.
We
then
applied
factor
analysis
detect
variable
groupings
thus
controls
on
dynamics.
observed
consistent
counterclockwise
patterns
between
watersheds.
This
was
indicative
distal
contributions
and/or
late‐event
mobilization
flushing,
which
controlled
event
hydrology
(such
as,
duration
magnitude
discharge).
However,
loops
indicated
different
delivery
behaviours
The
smaller
watershed
with
more
diverse
land
use
demonstrated
clockwise
indicating
early
flushing
or
rapidly
responding
pathways.
time
lag
discharge
peaks
identified
as
driver
site.
contrast,
larger
showed
dilution
versus
well
pathways
events.
driven
peak
range
demonstrating
an
increase
stream
power
scale
influenced
at
site
that
switched
behaviour.
result
critical
management,
especially
context
changing
climate
further
underscores
utility
data
offer
deep
insights
processes
contaminant
delivery.
PLoS ONE,
Год журнала:
2022,
Номер
17(7), С. e0271458 - e0271458
Опубликована: Июль 13, 2022
Accurate
and
sufficient
water
quality
data
is
essential
for
watershed
management
sustainability.
Machine
learning
models
have
shown
great
potentials
estimating
with
the
development
of
online
sensors.
However,
accurate
estimation
challenging
because
uncertainties
related
to
used
input.
In
this
study,
random
forest
(RF),
support
vector
machine
(SVM),
back-propagation
neural
network
(BPNN)
are
developed
three
sampling
frequency
datasets
(i.e.,
4-hourly,
daily,
weekly)
five
conventional
indicators
temperature
(WT),
hydrogen
ion
concentration
(pH),
electrical
conductivity
(EC),
dissolved
oxygen
(DO),
turbidity
(TUR))
as
surrogates
individually
estimate
riverine
total
phosphorus
(TP),
nitrogen
(TN),
ammonia
(NH
4
+
-N)
in
a
small-scale
coastal
watershed.
The
results
show
that
RF
model
outperforms
SVM
BPNN
terms
estimative
performance,
which
explains
much
variation
TP
(79
±
1.3%),
TN
(84
0.9%),
NH
-N
(75
when
using
4-hourly
dataset.
higher
would
help
obtain
significantly
better
performance
nutrient
measures
(4-hourly
>
daily
R
2
NSE
values.
WT,
EC,
TUR
were
key
input
estimations
RF.
Our
study
highlights
importance
high-frequency
development.
be
viable
watersheds
important
local
security.
Environmental Monitoring and Assessment,
Год журнала:
2024,
Номер
196(3)
Опубликована: Фев. 9, 2024
Abstract
Increases
in
fluxes
of
nitrogen
(N)
and
phosphorus
(P)
the
environment
have
led
to
negative
impacts
affecting
drinking
water,
eutrophication,
harmful
algal
blooms,
climate
change,
biodiversity
loss.
Because
importance,
scale,
complexity
these
issues,
it
may
be
useful
consider
methods
for
prioritizing
nutrient
research
representative
drainage
basins
within
a
regional
or
national
context.
Two
systematic,
quantitative
approaches
were
developed
(1)
identify
that
geospatial
data
suggest
are
most
impacted
by
nutrients
(2)
variability
factors
sources
transport
order
prioritize
studies
seek
understand
key
drivers
impacts.
The
“impact”
approach
relied
on
variables
representing
surface-water
groundwater
concentrations,
N
P,
potential
receptors
(i.e.,
ecosystems
human
health).
“variability”
nutrients,
model
accuracy,
receptor
One
hundred
sixty-three
throughout
contiguous
United
States
ranked
nationally
18
hydrologic
regions.
Nationally,
top-ranked
from
impact
concentrated
Midwest,
while
those
dispersed
across
nation.
Regionally,
basin
selected
two
differed
15
regions,
with
having
lower
minimum
concentrations
larger
ranges
than
approach.
highest
identified
using
advantages
exploring
how
landscape
affect
quality
ecosystems.
In
contrast,
prioritized
terms
development
both
surface
water
groundwater,
thereby
targeting
areas
where
actions
reduce
could
largest
effect
improving
availability
reducing
ecosystem
Hydrological Processes,
Год журнала:
2023,
Номер
37(9)
Опубликована: Авг. 31, 2023
Abstract
Excess
nitrate
and
sediment,
mobilized
by
precipitation
events
transported
into
surface
waters,
is
a
global
water
quality
challenge.
Recent
advances
in
high‐frequency
situ
monitoring
sensors
have
created
opportunities
to
investigate
constituent
concentration
dynamics
during
short‐term
hydrological
changes.
In
this
study,
we
characterized
the
event‐scale
variability
of
()
turbidity
(a
surrogate
for
sediment
transport)
two
large
agricultural
watersheds
Upper
Mississippi
River
Basin
using
hysteresis
loop
characteristics
determine
sources
dominant
transport
mechanisms.
We
then
applied
factor
analysis
detect
variable
groupings
thus
controls
on
dynamics.
observed
consistent
counterclockwise
patterns
between
watersheds.
This
was
indicative
distal
contributions
and/or
late‐event
mobilization
flushing,
which
controlled
event
hydrology
(such
as,
duration
magnitude
discharge).
However,
loops
indicated
different
delivery
behaviours
The
smaller
watershed
with
more
diverse
land
use
demonstrated
clockwise
indicating
early
flushing
or
rapidly
responding
pathways.
time
lag
discharge
peaks
identified
as
driver
site.
contrast,
larger
showed
dilution
versus
well
pathways
events.
driven
peak
range
demonstrating
an
increase
stream
power
scale
influenced
at
site
that
switched
behaviour.
result
critical
management,
especially
context
changing
climate
further
underscores
utility
data
offer
deep
insights
processes
contaminant
delivery.
