GEOGRAPHIC INFORMATION

Central and Southwest Montana Land Cover Classification, 1994-2001

Data Provider Wildlife Spatial Analysis Lab, The University of Montana
Date 06/28/1994 - 07/24/2001
Content Type Offline Data
Abstract SILC3REGIONZ is an ArcInfo 30 meter region grouped grid (raster file) of ground feature polygons derived from nine Landsat Thematic Mapper (TM) images across west-central Montana. Each of the nine Landsat TM images were processed separately and were then edgematched together to form one GIS region database.First, each Landsat image was delineated into regions in an unsupervised classification. Second, each region was assigned a land cover type label in a supervised classification. Regions classified as conifer cover types were also assigned labels for tree size class and canopy cover. A total of 31 land cover type classes, 5 tree size classes, and 5 conifer canopy cover classes were labeled across the nine scene area. Accuracies were estimated for the land cover type and tree size classifications of each Landsat image. Third, the regions from all nine Landsat images were edgematched together into the SILC3REGIONZ database. Below is a description of how the original Landsat images were delineated into ground feature regions, how the regions were labeled to land cover type, tree size, and tree canopy, and how the nine Landsat images were edgematched into one database.Image Landsat Image-Date Covertype-Acc Treesize-Acc SCENEPOLY-ID -------------------------------------------------------------------------- P40R27 7 7/27/99 69.8% 64.0% 49000001 .. P40R28 5 7/26/96 69.0% 57.1% 50000001 .. P39R27 5 7/01/95 73.5% 61.8% 51000001 .. P39R28 5 6/28/94 74.7% 69.6% 52000001 .. P39R29 5 6/28/94 75.7% 54.7% 53000001 .. P38R27 5 7/12/96 75.9% 55.9% 54000001 .. P38R28 5 7/12/96 74.6% 64.5% 55000001 .. P38R29 5 7/12/96 66.0% 57.9% 56000001 .. P37R29 5 7/24/00 64.9% 66.9% 57000001 ..Each image was run through an unsupervised classification to classify the approximately 56 million pixels into 130-150 spectral classes. A potential natural vegetation (PVT) classification provided by Region One of the USDA Forest Service was included as a seed source in the unsupervised classification. Using an iterative classification process with spectral signature files and PVT seed, each pixel was assigned to a spectral class. The pixels were then merged into regions (raster polygons) through a multi-stage merge algorithm using a variable minimum map unit based on heterogeneity of the surrounding pixels. Regions larger than 202.4 hectares were divided until all regions in the grid were less than 202.4 hectares (500 acres). The final unsupervised classification resulted in the creation of regions ranging in size from 0.1 hectare to 202.2 hectares. Each region was assigned a set of attributes for TM channels 1-7 and panchromatic from the imagery, along with elevation, aspect, and slope from the 30 meter digital elevation model (DEM); these attribute values were calculated based on the mean values of the 30 meter pixels within each region.Vegetation overstory (land cover type) was labeled using a supervised classification. The land cover type supervised classification was performed using a combination of manual and training data classifications. The following classes were manually labeled: urban, irrigated and non-irrigated agriculture, recently burned areas, water, mines, snow, and clouds. The other land cover types were labeled using training data and spatial classifiers. The training data were screened for data attribute accuracy, positional accuracy, and agreement with the imagery. The land cover type labels were filled into the COVERTYPE field of each scenes region grid.COVERTYPE DESCRIPTION ------------------------------------------------ 1100 Urban or Developed Lands 2010 Agricultural - Dry 2020 Agricultural - Irrigated 3130 Very Low Cover Grasslands 3150 Low / Moderate Cover Grasslands 3170 Moderate / High Cover Grasslands 3610 Mesic Shrublands 3625 Sagebrush / Xeric Shrublands 4101 Aspen 4150 Mixed Broadleaf / Cottonwood Forest 4203 Lodgepole Pine 4204 Whitebark Pine 4205 Limber Pine 4206 Ponderosa Pine 4212 Douglas-fir 4214 Rocky Moutain Juniper 4215 Western Larch 4216 Utah Juniper 4223 Douglas-fir/Lodgepole Pine 4230 Douglas-fir/Ponderosa Pine 4237 Subalpine Fir/Spruce 4241 Mixed Upper Subalpine Conifer Forest 4242 Mixed Lower Subalpine Conifer Forest 4244 Mixed Xeric Conifer Forest 4400 Burns 5000 Water 7300 Rock 7500 Mines/Quarries 9100 Snow 9800 Cloud 9900 Cloud ShadowConifer tree size and canopy cover labels were assigned using a training data classification. The training data were screened for data attribute accuracy, positional accuracy, and agreement with the imagery. Due to a high level of disagreement between the training data tree canopy call (see accuracy assessment), and the imagery, the tree canopy data was recoded based on MNDVI splits. The tree size labels were filled into the TREESIZE field and the tree canopy cover labels were filled into the TREECANOPY field of each scenes region grid.TREESIZE DESCRIPTION ------------------------------------- 1 Sapling 1.0-4.9" DBH 2 Pole 5.0-8.9" DBH 3 Medium 9.0-14.9" DBH 4 Large 15.0-20.9" DBH 5 Very Large 21.0-99.0" DBHTREECANOPY DESCRIPTION ------------------------------------- 1 1-9% Cover 2 10-24% Cover 3 25-44% Cover 4 45-64% Cover 5 65-100% CoverA cross validation (leave-one-out), accuracy assessment for land cover type and tree size of each scene was performed using the entire training data set. No estimate of accuracy was performed on the manually classified land cover types.Edgematching was done by selecting regions from only one of the scenes in overlap areas. First, the imagery was visually analyzed to select cloud free or snow free areas in overlap zones. Next, the images were ranked based on overall image quality. Finally, after the land cover type classification, regions were selected that created a consistant covertype pattern across the transition zone from one scene to another. The end result was a region grid with 4,820,703 regions.Image Landsat Date Priority Number of Regions Used ------------------------------------------------------------- P40R27 7 07/27/99 1 754,813 P40R28 5 07/26/96 2 580,429 P39R27 5 07/01/95 3 290,811 P39R28 5 06/28/94 4 315,795 P39R29 5 06/28/94 5 472,441 P37R29 7 07/24/00 6 684,885 P38R27 5 07/12/96 7 683,615 P38R28 5 07/12/96 8 628,551 P38R29 5 07/12/96 9 409,363 ------------------------------------------------------------- Total Regions in Database 4,820,703To help track similarities and differences in map legends between this classification and previous ones (SILC1 and MT-GAP) cover type names and codes numbers were not changed if the actual types were mapped using similar training data. Please see the individual scene report documents for further details.
Purpose This land cover classification from the nine Landsat TM scenes was prepared for the Eastside Assessment Area under contract to the USDA Forest Service. These data were produced to delineate ground features and map existing land cover in a standardized, consistent manner across the project area. This land cover grid is suited for analysis at the regional, sub-regional, and landscape levels; it can also provide support for many management disciplines, including timber, wildlife, fisheries, and recreation.
Supplemental Information
The Montana State Library Geographic Information Services provides this product/service for informational purposes only. The Library did not produce it for, nor is it suitable for legal, engineering, or surveying purposes. Consumers of this information should review or consult the primary data and information sources to ascertain the viability of the information for their purposes. The Library provides these data in good faith but does not represent or warrant its accuracy, adequacy, or completeness. In no event shall the Library be liable for any incorrect results or analysis; any direct, indirect, special, or consequential damages to any party; or any lost profits arising out of or in connection with the use or the inability to use the data or the services provided. The Library makes these data and services available as a convenience to the public, and for no other purpose. The Library reserves the right to change or revise published data and/or services at any time. This data set is provided "as-is" without warranty of any kind, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. The user assumes all responsibility for the accuracy and suitability of this data set for a specific application. In no event will the creators, the University of Montana, or the USDA Forest Service, be liable for any damages, including lost profits, lost savings, or other incidental or consequential damages arising from the use of or inability to use this data set. Use of these data requires the ability to read ArcInfo Grid data sets. Users must assume responsibility for determining the suitability of these data for their purposes. Not for use at scales greater than 1:100000.
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Distribution liability The Montana State Library Geographic Information Services provides this product/service for informational purposes only. The Library did not produce it for, nor is it suitable for legal, engineering, or surveying purposes. Consumers of this information should review or consult the primary data and information sources to ascertain the viability of the information for their purposes. The Library provides these data in good faith but does not represent or warrant its accuracy, adequacy, or completeness. In no event shall the Library be liable for any incorrect results or analysis; any direct, indirect, special, or consequential damages to any party; or any lost profits arising out of or in connection with the use or the inability to use the data or the services provided. The Library makes these data and services available as a convenience to the public, and for no other purpose. The Library reserves the right to change or revise published data and/or services at any time.
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Metadata date 04/19/2013