WANG Yong-feng, HE Cai-xia, JING Juan-li
Journal of Guilin University of Technology.
2022, 42(1):
131-140.
Drought
usually
induces
great
loss
to
ecosystem
and
social
economy.
It
is
of
great
significance
to
reveale
spatial
and
temporal
patterns
of
drought
in
preventing
drought
and
disaster
to
maintain
ecosystem
health.
Based
on
the
standardized
precipitation
evapotranspiration
index
(SPEI)
dataset
from
1902
to
2018,
the
spatiotemporal
evolution
characteristics
of
drought
were
analyzed
by
Mann-Kendall
mutation
test,
trend
analysis
and
empirical
orthogonal
function
(EOF)
analysis.
The
results
showed
that
from
the
aspect
of
temporal
variation,
there
was
no
significant
decreasing
trend
of
SPEI
at
the
interannual
and
seasonal
scales,
and
no
significant
mutation
point
was
found.
In
terms
of
spatial
changing
trend,
the
annual
and
seasonal
SPEI
showed
a
decreasing
trend,
and
the
drying
trend
was
more
significant
in
karst
areas
than
that
in
non-karst
areas.
At
seasonal
and
interannual
scales,
the
contribution
rates
of
the
first
three
cumulative
variance
of
EOF
eigenvector
decomposed
were
higher
than
75%.
EOF1
reflected
the
uniform
distribution
characteristics
in
this
district,
while
EOF2
and
EOF3
reflected
the
characteristics
of
north-south
and
east-west
reverse
distribution
respectively.
At
the
seasonal
and
interannual
scale,
the
changing
trend
of
the
corresponding
time
coefficients
were
different.
In
conclusion,
the
spatiotemporal
variation
characteristics
of
drought
were
revealed
in
the
southwest
karst
core
areas,
and
the
spatial
distribution
pattern
of
drought
was
clarified.
The
research
results
could
provide
scientific
basis
for
drought
warning
and
ecosystem
security
in
the
region.
