Wisconsin Coasts in Transition Report
Algoma Area (includes Town of Ahnapee, City of Algoma)
Examining land cover changes offers a means for understanding how a region’s
landscape is changing over time. Wisconsin’s Coasts in Transition tool uses
Coastal Change Analysis Program (C-CAP) data provided by NOAA’s Coastal
Services Center to view and analyze land cover changes. While NOAA’s C-CAP
data looks at land cover changes at the county level, Wisconsin’s Coasts in
Transition examines land cover changes at the municipal level. By grouping two
or more adjacent municipalities and considering their changing landscapes over
time, planners and managers can understand the effects of previous land use
decisions and consider implications on future land use planning in their coastal
region.
Wisconsin’s Coasts in Transition utilizes remotely sensed satellite images obtained
from NOAA to document changes in regional landscapes from 1996 to 2006. The
2006 land cover profile includes seventeen land cover categories which are found
across coastal Wisconsin.
These categories are then aggregated to simplify the report tabulation. The
following eleven land cover classes are examined in this report to indicate the
effects of development on Wisconsin’s coastal region: high/medium intensity
developed, low intensity developed, developed open space, grassland, agriculture,
forested, scrub/shrub, woody wetland, emergent wetland, barren land and open
water.
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Land Cover Change Algoma Area:
Land Cover Categories
High/Medium Intensity Developed
Low Intensity Developed
Open Space Developed
Grassland
Agriculture
Forested
Scrub/Shrub
Woody Wetland
Emergent Wetland
Barren Land
Open Water
Total
Area 1996 Area Lost
0.64
2.33
0.07
0.09
24.00
1.19
0.39
4.35
0.11
0.25
0.19
33.61
0.00
-0.01
0.00
-0.02
-0.06
-0.01
-0.03
-0.02
0.00
-0.05
-0.03
-0.21
Area
Gained
0.04
0.03
0.00
0.00
0.03
0.03
0.01
0.02
0.02
0.03
0.00
0.21
Area 2006
0.68
2.35
0.08
0.07
23.97
1.21
0.37
4.36
0.13
0.23
0.17
33.61
Net
Change
0.04
0.02
0.00
-0.02
-0.02
0.02
-0.02
0.01
0.02
-0.02
-0.02
Percent
Change
5.45%
0.90%
1.40%
-19.76%
-0.10%
2.05%
-5.34%
0.12%
13.66%
-6.42%
-12.89%
This chart indicates the change in various land cover categories between 1996 and 2006.
This chart compares the area of various land cover classes over time.
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This chart depicts the distribution of change in land cover categories over time.
How is developed land cover defined in the Wisconsin Coasts in Transition tool?
Per NOAA’s Digital Coast C-CAP information:
Developed, High Intensity – contains significant land area covered by concrete, asphalt, and other
constructed materials. Vegetation, if present, occupies less than 20 percent of the landscape. Constructed
materials account for 80 to 100 percent of the total cover. This class includes heavily built-up urban
centers and large constructed surfaces in suburban and rural areas with a variety of land uses.
Developed, Medium Intensity – contains areas with a mixture of constructed materials and
vegetation or other cover. Constructed materials account for 50 to 79 percent of total area. This class
commonly includes multi- and single-family housing areas, especially in suburban neighborhoods, but
may include all types of land use.
Developed, Low Intensity – contains areas with a mixture of constructed materials and substantial
amounts of vegetation or other cover. Constructed materials account for 21 to 49 percent of total area.
This subclass commonly includes single-family housing areas, especially in rural neighborhoods, but may
include all types of land use.
Developed, Open Space – contains areas with a mixture of some constructed materials, but mostly
managed grasses or low-lying vegetation planted in developed areas for recreation, erosion control, or
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aesthetic purposes. These areas are maintained by human activity such as fertilization and irrigation, are
distinguished by enhanced biomass productivity, and can be recognized through vegetative indices based
on spectral characteristics. Constructed surfaces account for less than 20 percent of total land cover.
Impervious Surfaces (per NOAA’s Digital Coast C-CAP information):
The impervious values were calculated based on the four classes of developed lands (we include
OSD as well). Each category of developed was assigned an average percent impervious value
based on a 2001 USGS percent impervious layer. The average values are HID = .8503, MID =
.5768, LID = .2929, and OSD = .0941. What this means is that High Intensity Developed lands
were 85.03% impervious on average.
Changes in Developed Lands Algoma Area:
When analyzing development as one of the reasons for land cover change within a geographical
area, it is interesting to explore the impacts of population changes. Within the two municipalities
comprising the Algoma study area, the population in 2000 was 4,334. The population in 2010
for this area was 4107. This represents a decrease in population of 227 persons, or -5.24
percent.
The geographical area of the Algoma study region is 33.61 square miles. In 1996, there were
approximately 3.05 square miles of developed lands within the Algoma study area. By 2006,
there were 3.10 square miles of developed lands, a net increase of .05 square miles under
development. The 2006 developed lands total represents 9.24 percent of the total study area. It is
estimated that this developed land (2006) included approximately 1.14 square miles of
impervious surfaces, or approximately 3.39 percent of the total study area.
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Algoma Area Development:
This pie chart shows a comparison of developed land categories to non-developed lands in 2006.
This chart indicates the increase of developed land by category between 1996 and 2006.
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This chart indicates which land cover categories became developed over time.
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