literature. Semi-analytical methods are typically region specific and applied to one
lake or a few lakes. They require ground-based measurements of the IOPs of each
lake for proper model calibration. More recent “adaptable” inversion algorithms
[59, 85] are more robust and have the potential to be able to be applied for regional
assessments of hundreds to thousands of lakes [84].
4 Regional Lake Water Quality Assessment: Case Studies
4.1 Water Quality of Inland Lakes
Early studies using Landsat imagery for water quality assessment were largely
exploratory and involved only one or a few lakes [71–76]. An exception is the work
of Martin et al. [86], who used semiautomated procedures to assess the trophic
status of around 3,000 lakes in Wisconsin using Landsat Multispectral Scanner
(MSS) imagery. The first regional assessment using Landsat TM imagery was
completed in the Twin Cities Metropolitan Area (Minnesota, USA) on the water
clarity of over 500 lakes [87]. Kloiber et al. [31, 88] followed with a temporal
assessment and statistical analysis of SD in those same lakes for the 1973 to 1998
period. A decrease in imagery costs corresponding with the launch of Landsat 7 in
April 1999, and the establishment of a NASA-funded Upper Midwest Regional
Earth Science Applications Center (RESAC) also in 1999, allowed for statewide
SD assessments for Minnesota, Wisconsin, and Michigan by the University of
Minnesota, University of Wisconsin-Madison, and Michigan State University.
After RESAC funding ended in 2003, Olmanson et al. [32] continued the remote
sensing for SD in Minnesota over eight periods from 1975 to 2008. A statistical
analysis of the spatial and temporal trends was recently published [89] (see
Sect. 4.2). Minnesota lake water clarity data can be accessed in the Lake
Browser [90].
The Wisconsin Department of Natural Resources also continued statewide
Landsat water clarity assessments on approximately 8,000 Wisconsin lakes annually [81]. All available clear late summer images are being processed for water
clarity assessment on an interannual basis (S. Greb, Wisconsin Department of
Natural Resources, personal communication, 2014). Wisconsin lake water clarity
data can be accessed in the Lakes and AIS Mapping Tool [91].
Since the original water clarity assessment of Michigan lakes in 2002 [82], the
United States Geological Survey (USGS) has continued statewide water clarity
assessments for ~3,000 lakes. The 2003–2005 and 2007–2008 assessments were
documented by Fuller et al. [83]. Since then, the USGS has conducted annual
assessments of water clarity in Michigan with 2009–2010 and 2011 completed
and 2013–2014 and 2000 assessments underway. Michigan water clarity data can
be accessed in the Michigan Lake Water Clarity Interactive Map Viewer [92].
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lake or a few lakes. They require ground-based measurements of the IOPs of each
lake for proper model calibration. More recent “adaptable” inversion algorithms
[59, 85] are more robust and have the potential to be able to be applied for regional
assessments of hundreds to thousands of lakes [84].
4 Regional Lake Water Quality Assessment: Case Studies
4.1 Water Quality of Inland Lakes
Early studies using Landsat imagery for water quality assessment were largely
exploratory and involved only one or a few lakes [71–76]. An exception is the work
of Martin et al. [86], who used semiautomated procedures to assess the trophic
status of around 3,000 lakes in Wisconsin using Landsat Multispectral Scanner
(MSS) imagery. The first regional assessment using Landsat TM imagery was
completed in the Twin Cities Metropolitan Area (Minnesota, USA) on the water
clarity of over 500 lakes [87]. Kloiber et al. [31, 88] followed with a temporal
assessment and statistical analysis of SD in those same lakes for the 1973 to 1998
period. A decrease in imagery costs corresponding with the launch of Landsat 7 in
April 1999, and the establishment of a NASA-funded Upper Midwest Regional
Earth Science Applications Center (RESAC) also in 1999, allowed for statewide
SD assessments for Minnesota, Wisconsin, and Michigan by the University of
Minnesota, University of Wisconsin-Madison, and Michigan State University.
After RESAC funding ended in 2003, Olmanson et al. [32] continued the remote
sensing for SD in Minnesota over eight periods from 1975 to 2008. A statistical
analysis of the spatial and temporal trends was recently published [89] (see
Sect. 4.2). Minnesota lake water clarity data can be accessed in the Lake
Browser [90].
The Wisconsin Department of Natural Resources also continued statewide
Landsat water clarity assessments on approximately 8,000 Wisconsin lakes annually [81]. All available clear late summer images are being processed for water
clarity assessment on an interannual basis (S. Greb, Wisconsin Department of
Natural Resources, personal communication, 2014). Wisconsin lake water clarity
data can be accessed in the Lakes and AIS Mapping Tool [91].
Since the original water clarity assessment of Michigan lakes in 2002 [82], the
United States Geological Survey (USGS) has continued statewide water clarity
assessments for ~3,000 lakes. The 2003–2005 and 2007–2008 assessments were
documented by Fuller et al. [83]. Since then, the USGS has conducted annual
assessments of water clarity in Michigan with 2009–2010 and 2011 completed
and 2013–2014 and 2000 assessments underway. Michigan water clarity data can
be accessed in the Michigan Lake Water Clarity Interactive Map Viewer [92].
132
L.G. Olmanson et al.