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 Shadow
Conifer 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" DBH
TREECANOPY DESCRIPTION ------------------------------------- 1 1-9% Cover 2 10-24% Cover 3 25-44% Cover 4 45-64% Cover 5 65-100% Cover
A 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 4,820,703
To 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.
Users accuracies of land cover types were:COVERTYPE P40R27 P39R27 P38R27 P40R28 P39R28 P38R28 P39R29 P38R29 P37R29 ------------------------------------------------------------------------ 3130 80.4 71.4 71.0 62.9 90.4 66.7 77.2 59.0 74.4 3150 81.2 82.6 93.6 77.3 84.1 87.6 90.4 81.0 80.3 3170 65.4 68.3 49.1 79.3 82.1 76.9 92.4 71.0 79.0 3610 69.9 42.7 66.8 62.3 61.2 68.3 72.4 67.3 69.8 3625 54.4 86.0 80.7 75.5 57.4 69.3 80.7 74.8 50.5 4101 68.3 75.9 46.3 68.9 68.2 68.5 71.9 76.0 57.9 4150 88.1 81.3 91.2 78.3 80.5 90.6 98.6 45.1 67.0 4203 67.6 80.6 67.7 70.3 65.9 70.1 67.6 72.5 46.8 4204 54.5 43.8 61.8 74.0 90.5 59.6 75.0 52.2 60.8 4205 88.9 46.7 66.7 NA 78.3 55.9 NA 85.7 63.6 4206 58.0 43.2 93.0 59.6 52.0 74.4 NA 75.0 51.5 4212 77.9 75.6 69.7 71.7 83.9 79.3 79.3 63.4 70.8 4214 NA NA NA NA 62.9 NA NA NA NA 4215 48.0 NA NA NA NA NA NA NA NA 4216 NA NA NA NA NA NA NA NA 45.2 4223 48.0 74.8 43.4 48.8 67.3 44.7 44.4 48.4 36.1 4230 57.1 41.3 34.6 50.5 68.1 41.2 NA NA NA 4237 57.1 26.7 37.4 49.3 65.0 50.4 41.7 57.6 48.9 4240 49.8 34.7 30.0 47.8 68.2 49.3 30.8 57.6 44.3 7300 94.6 92.6 95.3 99.1 96.0 99.4 99.4 97.8 92.9 ------------------------------------------------------------------------ Overall 69.8 73.5 75.9 69.0 74.7 74.6 75.7 66.0 64.9
Users accuracies of conifer tree size classes were:
TREESIZE P40R27 P39R27 P38R27 P40R28 P39R28 P38R28 P39R29 P38R29 P37R29 ------------------------------------------------------------------------ 1 Sapling 64.7 61.4 55.5 46.3 17.9 57.0 47.1 57.9 58.0 2 Pole 50.4 60.2 58.4 60.6 82.3 65.2 54.2 59.8 68.4 3 Medium 59.4 64.6 51.3 65.1 79.1 67.5 60.1 60.3 67.7 4 Large 70.2 40.7 72.7 51.1 25.7 42.1 23.5 41.9 0.0 5 VLarge 46.5 13.3 10.0 13.8 12.1 18.2 28.6 12.5 NA ------------------------------------------------------------------------ Overall 64.0 61.8 55.9 57.1 69.6 64.5 54.7 57.9 66.9
MAKE_DEM: extracted a digital elevation model (DEM) from the WSAL database for use during labeling.
MAKE_HYDROGRAPHY: extracted a hydrography coverage from the WSAL hydrography database for use during labeling.
BUILD_VAT: built an ArcInfo value attribute table (VAT) to hold all items (fields) for which descriptive data could be developed for each region. Filled in VALUE, COUNT, LINK, HECTARES, PERIMETER, TM1, TM2, TM3, TM4, TM5, TM6, TM7, PAN, TM1STD, TM2STD, TM3STD, TM4STD, TM5STD, TM6STD, TM7STD, PANSTD, MNDVI, ELE, SLP, ASP, and SLPASP fields.
The Mixed Conifer type 4240 was recoded to 3 types using an aml based on the PVTCODE and ELEVATION for the region. The 3 types are:
4241 Mixed Upper Subalpine Conifer Forest 4242 Mixed Lower Subalpine Conifer Forest 4244 Mixed Xeric Conifer Forest
1 very low cover 0-9% MNDVI < 10 2 low cover 10-24% MNDVI >= 10 and MNDVI < 50 3 low/mod cover 24-44% MNDVI >= 50 and MNDVI < 85 4 mod/high cover 44-64% MNDVI >= 85 and MNDVI < 125 5 high cover 64-100% MNDVI >= 125
CREATE CAN-SIZE CODE: A combined conifer canopy/sizeclass code was developed by multiplying the conifer canopy code by 100 and then adding the conifer sizeclass code. Thus for a plot with conifer canopy 2 (low cover - from above recode) and conifer sizeclass 3 (medium) the combined code would be:
(2 * 100) + 3 = 203
A total of 25 different conifer canopy/sizeclass codes were developed.
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 Shadow
TREESIZE DESCRIPTION ------------------------------------- -1 NOT CONIFER 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" DBH
TREECANOPY DESCRIPTION ------------------------------------- -1 NOT CONIFER 1 1-9% Cover 2 10-24% Cover 3 25-44% Cover 4 45-64% Cover 5 65-100% Cover
ASP Description -------------------- 0 Flat 1 North 2 Northeast 3 East 4 Southeast 5 South 6 Southwest 7 West 8 Northwest
COV_CODE_1 DESCRIPTION ------------------------------------------------ 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 4240 Mixed Conifer (recoded in COVERTYPE attribute based on PVT) 7300 Rock
MANLABEL DESCRIPTION -------------------------------- 1100 Urban or Developed Lands 2010 Agricultural - Dry 2020 Agricultural - Irrigated 4400 Burns 5000 Water 7500 Mines/Quarries 9100 Snow 9800 Cloud 9900 Cloud Shadow
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" DBH
TREECANOPY DESCRIPTION ------------------------------------- 1 1-9% Cover 2 10-24% Cover 3 25-44% Cover 4 45-64% Cover 5 65-100% Cover
PVTCODE DESCRIPTION ---------------------------------------------------------- 0 no pvt code assigned 1 abla1 (lower elevation subalpine fir type) 2 abla2 (high elevation subalpine fir type) 3 junipe 4 laly (alpine larch) 5 pial (whitebark pine type) 6 picea (spruce type) 7 pincon (lodgepole pine) 8 pifl (limber pine type) 9 pinpon (ponderosa pine) 10 poptre (cottonwood) 11 psemen (Douglas-fir type) 12 agric (agriculture type) 13 agrsmi 14 alpgrass (alpine grasslands type) 15 drygrass (xeric, valley bottom or foothills grassland type) 16 fesida (Idaho fescue type) 17 fessca (rough fescue type) 18 ripgrass (riparian grass type) 19 rock (rock dominated type) 20 bigsage (big sagebrush type) 21 dryshrub (non-sagebrush xeric shrub type) 22 messhrub 23 potfru (shrubby cinquefoil type) 24 rhusx 25 ripshrub (riparian shrub type) 27 urban 28 water 29 ripdecid (r1 westside broadleaf riparian) 33 pial/laly (r1 westside whitebark pine & alpine larch combined)
LIFEFORM DESCRIPTION --------------------- A Agriculture H Grass / Forb N Not applicable S Shrubland T Forest
SCENE RANGE
------------------------------
P40R27 49000001 - 49823122
P40R28 50014717 - 50767022
P39R27 51000001 - 51651551
P39R28 52028018 - 52732181
P39R29 53040844 - 53673240
P38R27 54000001 - 54749852
P38R28 55002880 - 55736579
P38R29 56023799 - 56803964
P37R29 57012146 - 57751176