Challenges and Opportunities in Integrated Hydrosystem Modelling: A Divide-Reduce-and-Conquer Approach to Overcome the Curse of Dimensionality
Presenter
Dr.
Young-Jin
Park
Earth
and
Environmental
Sciences
University
of
Waterloo
Astract
Integration
of
multiple
hydrologic,
geochemical,
and
ecological
processes
into
a
single
analysis
framework
is
destined
to
increase
the
dimensionality
of
the
problems
to
solve.
To
overcome
the
curse
of
dimensionality
in
integrated
hydrosystem
modelling
(IHSM),
a
divide-and-conquer
approach
is
discussed
as
a
potential
solution
strategy.
In
the
approach,
the
complex
models
are
divided
into
the
subproblems,
the
solutions
of
which
can
be
obtained
independently,
yet
interacting
with
their
neighbours.
It
is
demonstrated
that
the
efficiency
and
robustness
of
the
approach
depends
on
the
sizes
of
the
intersections
among
the
sub-problems.
The
results
suggest
that
the
optimal
design
of
sub-problems
is
a
key
for
success
in
its
applications.
The
scale
is
an
important
dimension
to
be
solved
in
IHSM.
To
simultaneously
solve
those
processes
of
different
scales,
a
divide-reduce-andconquer
approach
is
discussed.
A
necessary
and
sufficient
condition
is
derived
to
apply
the
approach
when
solving
two
interacting
sub-problems
of
different
scales.