U.S. Geological Survey, 20030901, National Land Cover Database Zone 01 Land Cover Layer: None None, U.S. Geological Survey, Sioux Falls, SD.
National Oceanographic and Atmospheric Administration (NOAA) Coastal Services Center (CSC)/Coastal Change Analysis Program (C-CAP), 20041001, C-CAP Washington 2000-Era Land Cover Metadata: NOAA Coastal Change Analysis Program (C-CAP), NOAA CSC, Charleston, SC.
This is a Raster data set. It contains the following raster data types:
The map projection used is Albers Conical Equal Area.
Planar coordinates are encoded using row and column
Abscissae (x-coordinates) are specified to the nearest 30.000000
Ordinates (y-coordinates) are specified to the nearest 30.000000
Planar coordinates are specified in meters
The horizontal datum used is North American Datum of 1983.
The ellipsoid used is Geodetic Reference System 80.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257222.
Sequential unique whole numbers that are automatically generated.
|1||No data value, Alaska zones only|
|11||Open Water - All areas of open water, generally with less than 25% cover or vegetation or soil|
|12||Perennial Ice/Snow - All areas characterized by a perennial cover of ice and/or snow, generally greater than 25% of total cover.|
|21||Developed, Open Space - Includes areas with a mixture of some constructed materials, but mostly vegetation in the form of lawn grasses. Impervious surfaces account for less than 20 percent of total cover. These areas most commonly include large-lot single-family housing units, parks, golf courses, and vegetation planted in developed settings for recreation, erosion control, or aesthetic purposes|
|22||Developed, Low Intensity -Includes areas with a mixture of constructed materials and vegetation. Impervious surfaces account for 20-49 percent of total cover. These areas most commonly include single-family housing units.|
|23||Developed, Medium Intensity - Includes areas with a mixture of constructed materials and vegetation. Impervious surfaces account for 50-79 percent of the total cover. These areas most commonly include single-family housing units.|
|24||Developed, High Intensity - Includes highly developed areas where people reside or work in high numbers. Examples include apartment complexes, row houses and commercial/industrial. Impervious surfaces account for 80 to100 percent of the total cover.|
|31||Barren Land (Rock/Sand/Clay) - Barren areas of bedrock, desert pavement, scarps, talus, slides, volcanic material, glacial debris, sand dunes, strip mines, gravel pits and other accumulations of earthen material. Generally, vegetation accounts for less than 15% of total cover.|
|32||Unconsolidated Shore* - Unconsolidated material such as silt, sand, or gravel that is subject to inundation and redistribution due to the action of water. Characterized by substrates lacking vegetation except for pioneering plants that become established during brief periods when growing conditions are favorable. Erosion and deposition by waves and currents produce a number of landforms representing this class.|
|41||Deciduous Forest - Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. More than 75 percent of the tree species shed foliage simultaneously in response to seasonal change.|
|42||Evergreen Forest - Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. More than 75 percent of the tree species maintain their leaves all year. Canopy is never without green foliage.|
|43||Mixed Forest - Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. Neither deciduous nor evergreen species are greater than 75 percent of total tree cover.|
|51||Dwarf Scrub - Alaska only areas dominated by shrubs less than 20 centimeters tall with shrub canopy typically greater than 20% of total vegetation. This type is often co-associated with grasses, sedges, herbs, and non-vascular vegetation.|
|52||Shrub/Scrub - Areas dominated by shrubs; less than 5 meters tall with shrub canopy typically greater than 20% of total vegetation. This class includes true shrubs, young trees in an early successional stage or trees stunted from environmental conditions.|
|71||Grassland/Herbaceous - Areas dominated by grammanoid or herbaceous vegetation, generally greater than 80% of total vegetation. These areas are not subject to intensive management such as tilling, but can be utilized for grazing.|
|72||Sedge/Herbaceous - Alaska only areas dominated by sedges and forbs, generally greater than 80% of total vegetation. This type can occur with significant other grasses or other grass like plants, and includes sedge tundra, and sedge tussock tundra.|
|73||Lichens - Alaska only areas dominated by fruticose or foliose lichens generally greater than 80% of total vegetation.|
|74||Moss- Alaska only areas dominated by mosses, generally greater than 80% of total vegetation.|
|81||Pasture/Hay - Areas of grasses, legumes, or grass-legume mixtures planted for livestock grazing or the production of seed or hay crops, typically on a perennial cycle. Pasture/hay vegetation accounts for greater than 20 percent of total vegetation.|
|82||Cultivated Crops - Areas used for the production of annual crops, such as corn, soybeans, vegetables, tobacco, and cotton, and also perennial woody crops such as orchards and vineyards. Crop vegetation accounts for greater than 20 percent of total vegetation. This class also includes all land being actively tilled.|
|90||Woody Wetlands - Areas where forest or shrub land vegetation accounts for greater than 20 percent of vegetative cover and the soil or substrate is periodically saturated with or covered with water.|
|91||Palustrine Forested Wetland* -Includes all tidal and non-tidal wetlands dominated by woody vegetation greater than or equal to 5 meters in height and all such wetlands that occur in tidal areas in which salinity due to ocean-derived salts is below 0.5 percent. Total vegetation coverage is greater than 20 percent.|
|92||Palustrine Scrub/Shrub Wetland* - Includes all tidal and non-tidal wetlands dominated by woody vegetation less than 5 meters in height, and all such wetlands that occur in tidal areas in which salinity due to ocean-derived salts is below 0.5 percent. Total vegetation coverage is greater than 20 percent. The species present could be true shrubs, young trees and shrubs or trees that are small or stunted due to environmental conditions.|
|93||Estuarine Forested Wetland* - Includes all tidal wetlands dominated by woody vegetation greater than or equal to 5 meters in height, and all such wetlands that occur in tidal areas in which salinity due to ocean-derived salts is equal to or greater than 0.5 percent. Total vegetation coverage is greater than 20 percent.|
|94||Estuarine Scrub/Shrub Wetland* - Includes all tidal wetlands dominated by woody vegetation less than 5 meters in height, and all such wetlands that occur in tidal areas in which salinity due to ocean-derived salts is equal to or greater than 0.5 percent. Total vegetation coverage is greater than 20 percent.|
|95||Emergent Herbaceous Wetlands - Areas where perennial herbaceous vegetation accounts for greater than 80 percent of vegetative cover and the soil or substrate is periodically saturated with or covered with water.|
|96||Palustrine Emergent Wetland (Persistent)* - Includes all tidal and non-tidal wetlands dominated by persistent emergent vascular plants, emergent mosses or lichens, and all such wetlands that occur in tidal areas in which salinity due to ocean-derived salts is below 0.5 percent. Plants generally remain standing until the next growing season.|
|97||Estuarine Emergent Wetland* - Includes all tidal wetlands dominated by erect, rooted, herbaceous hydrophytes (excluding mosses and lichens) and all such wetlands that occur in tidal areas in which salinity due to ocean-derived salts is equal to or greater than 0.5 percent and that are present for most of the growing season in most years. Perennial plants usually dominate these wetlands.|
|98||Palustrine Aquatic Bed* - The Palustrine Aquatic Bed class includes tidal and nontidal wetlands and deepwater habitats in which salinity due to ocean-derived salts is below 0.5 percent and which are dominated by plants that grow and form a continuous cover principally on or at the surface of the water. These include algal mats, detached floating mats, and rooted vascular plant assemblages.|
|99||Estuarine Aquatic Bed* - Includes tidal wetlands and deepwater habitats in which salinity due to ocean-derived salts is equal to or greater than 0.5 percent and which are dominated by plants that grow and form a continuous cover principally on or at the surface of the water. These include algal mats, kelp beds, and rooted vascular plant assemblages.|
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U.S. Geological Survey, NOAA, Space Imaging
The goal of this project is to provide the Nation with complete, current and consistent public domain information on its land use and land cover.
Person who carried out this activity:
Person who carried out this activity:
Data sources produced in this process:
According to accuracy assessment performed by Space Imaging, the
overall accuracy is 86.1% and 85.0% Kappa. The accuracy results shown
below are from a combined accuracy completed on both Oregon and Washington
C-CAP areas. A total of 1043 points are located in Washington and 1165
points are located in Oregon.
Each class accuracy is as follows: (Errors of Omission/Commission) 0 Background (N/A) 1 Unclassified (Cloud, Shadow, etc)(N/A) 2 High Intensity Developed (88%/98%) 3 Low Intensity Developed (99%/89%) 4 Cultivated Land (81%/79%) 5 Grassland (86%/81%) 6 Deciduous Forest (76%/81%) 7 Evergreen Forest (95%/90%) 8 Mixed Forest (80%/76%) 9 Scrub/Shrub (74%/88%) 10 Palustrine Forested Wetland (77%/78%) 11 Palustrine Scrub/Shrub Wetland (67%/70%) 12 Palustrine Emergent Wetland (83%/79%) 13 Estuarine Forested Wetland (N/A) 14 Estuarine Scrub/Shrub Wetland (N/A) 15 Estuarine Emergent Wetland (79%/79%) 16 Unconsolidated Shore (94%/96%) 17 Bare Land (88%/91%) 18 Water (98%/99%) 19 Palustrine Aquatic Bed (N/A) 20 Estuarine Aquatic Bed (100%/96%) 21 Tundra (N/A) 22 Snow/Ice (96%/100%)
The validation points were both collected in the field and photo interpreted. The accuracy assessment selection methods were developed to minimize spatial autocorrelation between the training and accuracy assessment. The first pool of accuracy assessment sites came from field data and photo interpretation of black and white digital orthophotos and digital color infrared imagery (primarily Emerge and Ikonos data). These sites were collected prior to initial mapping and were collected at the same time as the training data. The sites were selected to capture the physical and spectral diversity of the land cover. After these sites were identified, they were separated into training and accuracy assessment sites by imposing a 1 km x 1 km grid over the study area. Accuracy assessment sites could only be selected from alternate 1 km squares. Only 1 sample per class was allowed from each potential square. After the first criteria was met, the accuracy assessment sites were buffered to see if they fell within 1000 meters of another accuracy assessment site of the same class or within 1000 meters of a training site of the same class. Those that fell within the 1000 meter buffer were eliminated. All sites were to be from a homogeneous 3x3 area.
After an analysis of the point distribution, it became clear that there were not enough samples for every class. The remaining points were selected from the initial draft final classification and had to be a homogeneous 3x3 area. A stratified random sample was used to locate sites. These sites were restricted to the same alternate 1 km x 1 km grid that was used to separate training from AA sites in the initial analysis. Sampling was limited to areas where there was high resolution color infrared imagery. The imagery included the previous Ikonos and Emerge imagery, but also included an additional 60 scenes of Ikonos imagery. The additional Ikonos imagery provided sampling areas across the entire study area. When possible, we tried to identify 50 samples of the uncommon classes and 20 sites of the common classes. Samples were selected for the common classes so that there were samples for classes using this methodology.
In total, an additional 637 additional points to the accuracy assessment analysis for a total of 2208. All classes have a minimum of 50 accuracy assessment points except for estuarine aquatic bed and estuarine emergent. These classes have 24 and 29 sites respectively. These classes are limited in the study area and to some extent in the imagery that was available to sample from.
Also as part of the assessment, NOAA staff field tested the classification to determine a subjective goodness of fit.
Post-Processing Steps: None
Known Problems: None
Spatial Filters: None
This NLCD product of mapping zone 01 Land Cover layer is the version dated November 8, 2006.
The NLCD 2001 database for mapping zone 01 consists of three main data products including: (1) per pixel classified land-cover data (2) sub-pixel percent imperviousness and (3) sub-pixel percent tree canopy density. The land-cover database also includes three additional metadata layers that provide users a spatial node map of the land cover classification. The three layers are: (a) a spatial node map of the land cover classification, (b) a spatial confidence map of the land cover classification, and, (c) a text file of logical statements related to the land cover classification.
Conceptually, the descriptive tree is a classification tree generated by using the final minimum-map- unit land cover product (1 acre) as training data, and Landsat and other ancillary data as predictors. The goal of the descriptive tree is to summarize the effects of boosted trees (10 sequential classification trees) into a single condensed decision tree that can be used as a diagnostic tool for the classification process. This descriptive tree can be used to assess the relative importance of each of the input data sets on each land cover class. Such information may also be useful to customize the minimum-mapping-unit classification to meet a user's specific needs through raster modeling. Descriptive trees usually capture 60 to 80% of the information from the original land cover data.
The leaf or terminal nodes of the descriptive tree are assigned to sequential numbers (called node numbers) and mapped across the entire mapping zone on a pixel-by-pixel basis. These node numbers can then be matched with the various conditional statements associated with each respective terminal node. This spatial layer appears similar to a cluster map, but is the result of a supervised classification - not an unsupervised clustering. This node map can potentially be used as input by users to customize NLCD land cover, by linking the spatial extent of an individual node with the rules of the conditional statement.
The Land Cover spatial classification confidence data layer is provided to users to help determine the per-pixel spatial confidence of the NLCD 2001 land cover prediction from the descriptive tree. The C5 algorithm produces an estimate (a value between 0% and 100%) that indicates the confidence of rule predictions at each node based on the training data. This spatial confidence map should be considered as only one indicator of relative reliability of the land cover classification, rather than a precise estimate. Users should be aware that this estimate is made based on only training data, and is derived from a generalized descriptive decision tree that reproduces the final land cover data. However, this layer provides valuable insight for a user to determine the risk or confidence they choose to place in each pixel of land cover.
A logic statement from a descriptive tree classification describes each classification rule for each classified pixel. An example of the logic statement follows:
IF tasseled-cap wetness > 140 and imperviousness = 0 and canopy density < 4, then classify as Water
This logic file can be used in combination with the spatial node map to identify classification logic and allow modifications of the classification based on user's knowledge and/or additional data sets.
Additional information may be found at <http://www.mrlc.gov/mrlc2k_nlcd.asp>.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints: None
Although these data have been processed successfully on a computer system at the USGS, no warranty expressed or implied is made by the USGS regarding the use of the data on any other system, nor does the act of distribution constitute any such warranty. Data may have been compiled from various outside sources. Spatial information may not meet National Map Accuracy Standards. This information may be updated without notification. The USGS shall not be liable for any activity involving these data, installation, fitness of the data for a particular purpose, its use, or analyses results.
|Data format:||Arc/Info Export Format and/or ArcView Shapefile (version ArcGIS 9.0) ASCII Size: 0.001|
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