Water Resources Research,
Journal Year:
2021,
Volume and Issue:
57(7)
Published: June 14, 2021
Abstract
The
scaling
relationships
of
groundwater
contributions
have
been
examined
in
previous
studies,
but
whether
these
findings
are
site‐specific
or
applicable
to
other
watersheds
remains
unclear.
Here,
we
illustrate
how
differ
between
with
different
geology.
We
investigated
the
spatial
distributions
specific
discharge
(discharge
per
unit
drainage
area)
and
chemical
compositions
stream
spring
water
during
baseflow
periods
three
Cretaceous
Eocene
sedimentary
Neogene
volcanic
Ishikari
River
basin,
Japan.
End‐member
mixing
analysis
was
used
separate
into
shallow
deep
groundwater.
only
significantly
increased
area
for
two
study
sites.
Conversely,
ratio
both
sites,
These
indicate
that
flow
played
a
crucial
role
making
geology‐dependent
differences
relationships.
geological
effects
on
were
likely
characterized
by
distribution
highly
permeable
bedrock
layer.
This
control
provides
useful
framework
generalizing
knowledge
about
contributions.
Reviews of Geophysics,
Journal Year:
2019,
Volume and Issue:
57(3), P. 835 - 965
Published: April 30, 2019
Abstract
Groundwater
18
O/
16
O,
2
H/
1
H,
13
C/
12
C,
3
and
14
C
data
can
help
quantify
molecular
movements
chemical
reactions
governing
groundwater
recharge,
quality,
storage,
flow,
discharge.
Here,
commonly
applied
approaches
to
isotopic
analysis
are
reviewed,
involving
recharge
seasonality,
elevations,
ages,
paleoclimate
conditions,
Reviewed
works
confirm
long
held
tenets:
(i)
that
derives
disproportionately
from
wet
season
winter
precipitation;
(ii)
modern
groundwaters
comprise
little
global
groundwater;
(iii)
“fossil”
(>12,000‐year‐old)
dominate
aquifer
storage;
(iv)
fossil
capture
late‐Pleistocene
climate
conditions;
(v)
surface‐borne
contaminants
more
common
in
younger
groundwaters;
(vi)
discharges
generate
substantial
streamflow.
isotope
midlatitudes
sedimentary
basins
equipped
for
irrigated
agriculture,
but
less
plentiful
across
high
latitudes,
hyperarid
deserts,
equatorial
rainforests.
Some
of
these
underexplored
systems
may
be
suitable
targets
future
field
testing.
Ecohydrology,
Journal Year:
2018,
Volume and Issue:
11(3)
Published: Feb. 12, 2018
Abstract
The
páramo
ecosystem
provides
most
of
the
water
for
tropical
Andean
highlands
in
South
America.
Although
comprehension
this
environment
has
increased
lately,
there
remains
an
urgent
need
to
quantify
processes
involved
hydrological
cycle.
Interception
loss
(IL)
is
one
least
studied
páramo,
and
more
generally,
grasslands
globally.
main
objective
study
was
IL
at
event
scale
by
estimating
it
indirectly
from
precipitation
(P)
effective
rainfall
(ER).
Furthermore,
following
questions
were
assessed:
(a)
how
much
P
becomes
ER?
(b)
what
impact
on
calculations
using
a
rain
gauge
instead
disdrometer?
(c)
which
meteorological
variables
are
related
process?
(d)
possible
estimate
variables?
High
percentages
relation
found
(10–100%).
canopy
storage
capacity
tussock
grasses
approximately
2
mm.
disdrometer
observations
led
accurate
results
than
because
only
registers
light
precipitation,
horizontal
drizzle
that
increases
amount
P,
ER,
estimates.
Also,
we
strongly
correlated
with
P;
can
be
estimated
multiple
linear
regression
(R
=
0.9)
relative
humidity
events
where
1.7
<
8.5
These
findings
show
important
role
provide
stepping
stone
modelling
resources.
Water Resources Research,
Journal Year:
2018,
Volume and Issue:
54(3), P. 1812 - 1830
Published: Feb. 26, 2018
Abstract
Land
use
change
alters
nitrate
(NO
3
‐N)
dynamics
in
stream
water
by
changing
nitrogen
cycling,
nutrient
inputs,
uptake
and
hydrological
flow
paths.
There
is
little
empirical
evidence
of
these
processes
for
East
Africa.
We
collected
a
unique
2
year
high‐resolution
data
set
to
assess
the
effects
land
(i.e.,
natural
forest,
smallholder
agriculture
commercial
tea
plantations)
on
NO
‐N
three
subcatchments
within
headwater
catchment
Mau
Forest
Complex,
Kenya's
largest
tropical
montane
forest.
The
forest
subcatchment
had
lowest
concentrations
(0.44
±
0.043
mg
N
L
−1
)
with
no
seasonal
variation.
(1.09
0.11
plantation
(2.13
0.19
closely
followed
discharge
patterns,
indicating
mobilization
during
rainy
seasons.
Hysteresis
patterns
rainfall
events
indicate
shift
from
subsurface
surface
runoff
agricultural
subcatchments.
Distinct
peaks
were
observed
after
longer
dry
period
enabled
us
identify
differences
transport
catchments
under
different
use,
such
as
enhanced
inputs
season
higher
annual
export
(4.9
0.3
12.0
0.8
kg
ha
yr
than
(2.6
0.2
).
This
emphasizes
usefulness
our
monitoring
approach
improve
understanding
riverine
exports
landscapes,
but
also
need
apply
methods
other
regions.
Hydrology and earth system sciences,
Journal Year:
2018,
Volume and Issue:
22(9), P. 4981 - 5000
Published: Sept. 27, 2018
Abstract.
Conversion
of
natural
forest
(NF)
to
other
land
uses
could
lead
significant
changes
in
catchment
hydrology,
but
the
nature
these
has
been
insufficiently
investigated
tropical
montane
catchments,
especially
Africa.
To
address
this
knowledge
gap,
we
aimed
identify
stream
water
(RV)
sources
and
flow
paths
three
sub-catchments
(27–36
km2)
with
different
use
(natural
forest,
NF;
smallholder
agriculture,
SHA;
commercial
tea
tree
plantations,
TTP)
within
a
1021
km2
Mau
Forest
complex,
Kenya.
Weekly
samples
were
collected
from
water,
precipitation
(PC)
mobile
soil
for
75
weeks
analysed
stable
isotopes
(δ2H
δ18O)
mean
transit
time
(MTT)
estimation
two
lumped
parameter
models
(gamma
model,
GM;
exponential
piston
EPM)
calculation
young
fraction.
potential
endmembers
over
period
55
Li,
Na,
Mg,
K,
Rb,
Sr
Ba
endmember
mixing
analysis
(EMMA).
Solute
concentrations
lower
than
all
catchments
(p
<
0.05),
whereas
springs,
shallow
wells
wetlands
generally
more
similar
water.
The
isotope
signal
was
considerably
damped
compared
precipitation.
Mean
suggested
long
times
(up
4
years)
sub-catchments,
model
efficiencies
very
low.
fraction
ranged
13
%
agriculture
sub-catchment
15
plantation
sub-catchment.
3.2–3.3
soils
4.5–7.9
pasture
at
cm
depth
10.4–10.8
50
depth.
contribution
springs
discharge
increased
median
16.5
(95
confidence
interval:
11.3–22.9),
2.1
(−3.0–24.2)
50.2
(30.5–65.5)
during
low
20.7
(15.2–34.7),
53.0
(23.0–91.3)
69.4
(43.0–123.9)
high
respectively.
Our
results
indicate
that
groundwater
is
an
important
component
irrespective
use.
further
suggest
selected
tracers
might
not
be
appropriate
highly
signatures.
A
in-depth
investigation
dependence
using
tracers,
such
as
tritium,
therefore
shed
light
on
effects
hydrological
behaviour
catchments.
