EPA and the states have a responsibility to assess the condition of the
water quality of the Nation’s lakes. According to EPA’s 2000
Water Quality Report the overall percentage of assessed lakes has not
increased in recent years and comparisons in that same report suggest
that the percentage may have decreased relative to previous assessments.
Financial resources at the federal, state and local level are insufficient
to assess lakes in a timely fashion using conventional methods.
Recent improvements in sensor design and advances in data analysis have
made the prospect of the remote sensing of lake-water quality an emerging
technology. The results from various projects that have been completed
to-date are quite promising and are now being used in some states (e.g.,
Michigan, Minnesota, Nebraska and Wisconsin) as part of their overall
lake assessment efforts. However, several questions remain concerning
the most appropriate platforms (sensors) for different applications; true
costs associated with the various platforms; availability of remote sensed
images and appropriateness of the various models for translating the images
into usable estimates of water quality; and various related details. The
North American Lake Management Society (NALMS) has recognized the role
remote sensing can play in the assessment of water quality and in this
project proposes to draw on the expertise of several universities and
states that have experience in remote sensing to answer these questions
and make these techniques more widely available for states interested
in using these technologies.
In this project we will conduct a retrospective assessment of several
different remote sensing platforms, with an emphasis on those remote sensing
methods (e.g., Landsat, MODIS and MERIS) that most likely can be used
for monitoring lakes routinely and operationally over a regional spatial
extent. This work will be conducted for various lakes across the Upper
Midwest (EPA Region 5) states. In addition in situ comparisons of the
various platforms on one or more lakes with simultaneously collected water
quality data will be done. Products anticipated from this project are:
a) A guidance document developed on effectiveness and use of remote sensing
for lake assessment; b) A prototype water clarity assessment created for
each participating state. c) A protocol using MERIS and MODIS developed
for large lakes; d) Training on the application of these technologies;
e) A dedicated issue of LakeLine Magazine, which will provide a user-friendly
format for sharing results from the project with other states, lake managers
and others who may be interested in using remote sensing to assess lake
or watershed characteristics.
In this project, NALMS and its collaborators will conduct a retrospective
assessment of several different remote sensing platforms, with an emphasis
of those remote-sensing methods (e.g., Landsat, MODIS and MERIS) that
most likely can be used for monitoring lakes routinely and operationally
over a regional spatial extent. This work will be conducted for various
lakes across the Upper Midwest states (EPA Region 5) as these states:
encompass several different ecoregions, including numerous and varied
lakes and reservoirs and have abundant data for groundtruthing from state
and volunteer monitoring programs (including numerous Secchi Dip-In participants).
In addition we will conduct an in situ comparison of the various platforms
on one or more lakes with simultaneously collected water quality data.
Each technique would be characterized in each of the following areas as
well:
| Sensor |
|
Spatial Resolution |
Spectral Resolution |
Spatial Coverage |
Notes |
| Proximal sensing |
In situ |
Very high |
High |
Low |
Selected water bodies |
Aircraft-based
Hyperspectral / Multispectral |
|
High |
High |
Low |
Selected water bodies |
Commercial High Res.
Satellite:
IKONOS & Quick Bird |
0.6 - 4.0 m |
High |
Low |
Low |
Small water bodies |
| Landsat |
30 m |
Moderate |
Moderate |
Moderate |
Archive: 1972 -present
lakes =10 acres |
| MERIS |
300 m |
Relatively Low |
High |
High |
Large water bodies |
| MODIS |
500 – 1000 m |
Low |
High |
High |
Large; daily coverage |
This effort will study watersheds that contain lakes across several size
ranges in the following states:
- Minnesota - a northern forested watershed;
- Illinois - an agricultural watershed in the Corn Belt Plains;
- Indiana - a watershed with a mix of agricultural and urban land
uses; and
- Ohio - a watershed with a mix of agricultural and urban land
uses.
This should provide coverage of several commonly encountered types of
ecoregional settings in the Upper Midwest and include a wide range of
lake types as well. The parameters and size of waterbodies that can be
assessed with each platform will be investigated. Using information from
our investigation and available waterbody GIS layers, the appropriateness
of each platform for different study areas may be determined. The states
will be responsible for gathering the ground truth data and much of this
work will be considered in-kind contributions to the overall project.
Wherever possible volunteer lake monitors will be involved in the collection
of ground truth data.
1. Boat-based remote sensing of Lake Minnetonka was completed on Monday
August 22 with the crew from U of N. Field assistance was provided by
Three Rivers Park District (John Barten, a NALMS member, is the manager
of their environmental program). MPCA will be paying for the lab analysis
of chlorophyll and TSS. We will also have an assessment of the relative
abundance of the dominant algal forms for each of the 17 sites that were
sampled. Once completed data will be forwarded to Anatoly and Don.
2. The AISA plane-based remote sensing of Minnetonka took place Tuesday
August 23, which should allow for a good comparison between boat &
plane -based platforms. Three Rivers did their routine field work on Minnetonka
on that date as well so there will be additional data available for groundtruthing
as needed.
3. MODIS - we finally got relatively clear skies over northern over the
weekend of August 6&7. Leif was insturmental in helping to track images
over these days. Groundtruth sampling was conducted several days prior
and after that date with major campaigns of Lake of the Woods and Rainy
Lake that were led by NALMS members Jesse Anderson (MPCA) and Bev Clark
(Ontario Ministry of Environment). Citizen volunteers on these lakes and
several lakes in western MN were prominent in this effort. Sampling was
conducted as well by Tim James and Jeff Hrubes of MPCA. Red Lake and Mille
Lacs Bands also assisted with sampling. I have mailed several thank you
letters to the groups who assisted with this effort. This data is now
being compiled and will be shared with collaborators. Jonathan (U of W)
will have primary responsibility for developing MODIS regressions.
4. Leif Olmanson has started Landsat work for Ohio. Dr. Bob Carlson has
provided some groundtruth data for this effort.