Introduction
Researchers
from the University
of Minnesota's
Water Resource Center,
and the Remote
Sensing and Geospatial
Analysis Laboratory
have been working
together since
1996, researching
and developing
satellite-based
approaches to monitor
water resources.
They have been
joined by resource
managers from
several local and
state agencies.
Together they are
committed to developing
satellite technology
as a cost effective
way to acquire
information on lakes,
streams and wetlands.
The
first research
utilizing satellite
remote sensing
for monitoring lake
water quality came
in the late 1970’s
at the University
of Minnesota by
Dr. Tom Lillesand.
Although the early
Landsat satellite
data were not
entirely
sufficient for
the operational
mapping of lake
clarity,
this work laid
the foundation
for our recent
research with
second generation
Landsat sensors.
In
1996, researchers in the Remote
Sensing Laboratory and Dr. Marvin
Bauer returned to pursue the application
of satellite imagery to water
resource monitoring. With help
from Dr. Patrick Brezonik and
the Water Resources Center, it
was determined that the satellite
data and the improvements in the
STORET water quality database
made the method not only viable,
but a cost effective way to monitor
lake-rich areas like those in
the Upper Great Lakes region.
Initial
external research interest came
from the Metropolitan Council
in 1997 and centered on the Twin
Cities Metro Area. Analysis of
twelve
dates
of imager from 1972 to 1998 established
that
given clear satellite data and
corresponding lake clarity
field data, the Landsat data could
be used to accurately classify
lake clarity data over time for
the more than 500 lakes in the
metro area.
As
part of the NASA
Upper Great
Lakes RESAC (Regional
Earth Science Applications
Center) project,
emphasis was placed
on
extending
the methodology
to the state and
regional levels.
University of Minnesota
researchers
joined
forces with Dr.
Lillesand (now
at University
of
Wisconsin- Madison)
and researchers
at Michigan State
University and
were able to successfully
create
statewide
censuses of lake
clarity information
for Minnesota,
Wisconsin and
Michigan.
The
Minnesota Department of Natural
Resources joined the effort in
2000 providing funds for determining
whether aquatic vegetation could
also be mapped using the recently
available high resolution commercial
satellite data. Several study
sites were selected and mapped
including Lake Minnetonka in Hennepin
County and Swan Lake in Nicollet
County, Minnesota.
Since
2003, the research has continued
with a project funded
by the Legislative Commission
for Minnesota Resources. Now emphasis
is being placed on creating historical
statewide censuses of lake water
clarity and analyzing the trends
and drivers of lake water clarity.
Refinements are being made to
the methodology in order to transfer
the technique to the state agencies
who steward water quality, namely
the Minnesota Pollution Control
Agency and the Minnesota Department
of Natural Resources.
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