Research Square (Research Square),
Journal Year:
2024,
Volume and Issue:
unknown
Published: Sept. 11, 2024
Abstract
The
quantitative
identification
of
nitrate
sources
is
great
significance
for
water
resources
management.
Stable
isotopes
combined
with
Bayesian
isotope
mixing
model
(SIAR)
were
widely
used
to
identify
nitrogen
sources.
However,
few
researchers
focus
on
the
influence
variations
source
isotopic
composition
contributions.
Here,
δ15N-NO3−
and
δ18O-NO3−
isotopes,
SIAR
model,
uncertainty
sensitivity
analysis
quantify
contributions
uncertainties
in
Huashan
watershed.
60
surface
samples
82
groundwater
collected
from
November
2021
October
2022,
atmospheric
deposition
(AD),
chemical
fertilizer
(NF),
soil
(SN),
manure
sewage
(M&S)
determined
as
potential
Source
by
indicated
that
M&S
was
main
contributor
water,
while
NF
groundwater.
In
April
contributed
most
mainly
originated
SN
MS.
variation
between
winter
spring
due
fertilization
rainfall.
showed
greatest
NF.
Sensitivity
changes
had
effect
results
δ15N,
whereas
only
mean
values
oxygen
AD
a
greater
δ18O.
Fertilizer
application
fertility
agricultural
rotations
cropping
practices
are
intrinsic
high
level
SN.
magnitude
end-member
standard
deviations
directly
affects
outcomes
analysis.
We
recommend
prioritizing
determination
feature
sensitive
end-members
during
sampling.
contribution
highlighting
need
optimize
irrigation
strategies
enhance
utilization
efficiency.
