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MELCD
2004 Products
Concepts:
MELCD 2004 landcover
MELCD 2004 imperviousness
minimum mapping unit
In these next sections,
we will cover all of the products available to end-users from the
combined Maine Landcover Dataset 2004 (MELCD 2004) and National
Landcover Dataset 2001 (NLCD 2001).
The MELCD 2004 products include a 5-meter resolution landcover dataset
and a 5-meter resolution imperviousness dataset. This project was
an integrated extension of the NLCD 2001 project for Maine.
MELCD 2004 Landcover
The landcover data are based on 2004 SPOT imagery fused (pan-sharpened)
with 2001 LandSat data (5m black-and-white data were merged with 30-m
color and infrared data, then classified). The pixel resolution
is 5-meters, with a minimum mapping
unit (MMU) of .89 acres. The MMU is the smallest area that
can be accurately mapped. In practice, some areas smaller than
the MMU are mapped in this layer, but they cannot be judged at the same
level of accuracy as the rest of these data. Accuracy as a whole,
based on a sample of 1671 points, is 75% according to the accuracy
report. Maximum scale recommended for this dataset is
1:24,000; it is designed for analyses at the town or subwatershed
level. For more complete information, read the metadata. The
classification includes 23 distinct classes:
Pixel
value Class
2 Developed, High
Intensity (80-100% impervious)
3 Developed, Medium
Intensity (50-79% impervious)
4 Developed, Low
Intensity (21-49% impervious)
5 Developed, Open Space
(developed areas, but 0-20% impervious - city parks, golf courses,
baseball fields, etc.)
6 Cultivated Crop
(production of annual crops such as corn, potatoes, strawberries, and
tilled barren fields)
7 Pasture/Hay (grasses
are major vegetation, managed for harvesting as hay or grazing)
8 Grassland/Herbaceous
(unmanaged grasslands - rare in Maine)
9 Deciduous Forest
(> 20% tree canopy cover, > 75% of trees are deciduous)
10 Evergreen Forest (> 20% tree
canopy cover, > 75% of trees are evergreen)
11 Mixed Forest (> 20%
tree canopy cover, 25-75% are deciduous)
12 Scrub/Shrub (woody
vegetation < 5m tall is > 20% of cover - typically regenerating
fields, cuts, or rights-of-way)
13 Wetland Forest (freshwater
wetland with > 20% tree canopy cover)
15 Wetland (all other wetlands)
16 Road/Runway (impervious road or
runway, but not in developed areas)
19 Unconsolidated Shore (rocky shore,
mudflats, sand beach, exposed lake shoreline)
20 Bare Ground (open quarries and
pits, granite outcrops and peaks)
21 Open Water (water bodies
typically > 10m wide)
22 Blueberry Field
(commercial blueberry operations)
23 Recent Clearcut (forested
area with > 90% canopy removal 2001-2004)
24 Light Partial Cut
(forested area with 20-50% canopy removal 1995-2001)
25 Heavy Partial Cut (forested area
with 50-100% canopy removal 1995-2001)
26 Regenerating Forest (forested
area with canopy increase 1995-2001)
27 Alpine (shrubby or grassy
vegetation above treeline on mountains)
MELCD 2004 Landcover data
showing Bangor, Maine.
MELCD 2004 Imperviousness Data
The imperviousness data indicates, at a 5-meter pixel resolution,
whether or not a pixel is 50% or more impervious (pixel value of 0) or
<50% impervious (pixel value of 1) based on 2004 satellite
data. Like the landcover data, the pixel resolution is 5-meters, with a minimum mapping unit
(MMU) of .89 acres. The MMU is the smallest area that can be
accurately mapped. In practice, some areas smaller than the MMU
are
mapped in this layer, but they cannot be judged at the same level of
accuracy as the rest of these data. Accuracy as a whole, based on
a
sample of 1444 points, is 94% according to the accuracy matrix.
Maximum scale recommended for this dataset is 1:24,000; it is designed
for analyses at the town or subwatershed level. For more complete
information, read the metadata.
MELCD 2004 imperviousness data
in Bangor, black is impervious (with rivers in blue for reference -
they would be considered pervious).
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