Three additional data sources were incorporated to improve thematic resolution: (1) the low-intensity residential and commercial/industrial/transportation layers from the USGS's North American Land Cover dataset; (2) the fallow agriculture layer from the land cover product of the COHYST (Cooperative Hydrological Study) project of the Central Platte, which was based on 1997 TM data; and (3) a subset of the National Wetlands Inventory polygonal data that enhanced the resolution of wetlands and riparian corridors. In addition the Omernik's Level III ecoregions was used to create the western boundary of the Upland Tallgrass Prairie class due to unavoidable spectral confusion between the Upland Tallgrass Prairie and Little Bluestem-Gramma Mixedgrass Prairie land cover classes.
University of Nebraska-Lincoln, School of Natural Resources, Center fo, 2005, Nebraska Land Cover Classification: University of Nebraska-Lincoln, School of Natural Resources, Center for Advanced Land Management Information Technologies (CALMIT), Lincoln, Nebraska.This is part of the following larger work.
, 2005, The Nebraska Gap Analysis Project Final Report.
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||Ponderosa Pine Forests and Woodlands|
|2||Deciduous Forests and Woodlands|
|5||Sandhills Upland Prairie|
|6||Lowland Tallgrass Prairie|
|7||Upland Tallgrass Prairie|
|8||Little Bluestem-Gramma Mixedgrass Prairie|
|9||Western Wheatgrass Mixedgrass Prairie|
|10||Western Shortgrass Prairie|
|14||Fallow Agricultural Field|
|15||Aquatic Bed Wetland|
|19||Low Intensity Residential|
|20||High Intensity Residential/Commercial/Industrial/Transportation|
1) Ponderosa Pine Forests and Woodlands I.A.8.N.b.10 Pinus ponderosa forest alliance II.A.4.N.a.32 Pinus ponderosa woodland alliance 2) Deciduous Forests and Woodlands I.B.2.N.a.8 Acer saccharum - Tilia Americana - (Quercus rubra) forest alliance I.B.2.N.a.27 Quercus alba - (Quercus rubra, Carya spp.) forest alliance I.B.2.N.a.33 Quercus macrocarpa forest alliance I.B.2.N.b.3 Betula papyrifera forest alliance II.B.2.N.a.20 Quercus macrocarpa woodland alliance 3) Juniper Woodlands II.A.4.N.a.8 Juniperus scopulorum woodland alliance 4) Sandsage Shrubland III.A.4.N.a.4 Artemisia filfolia shrubland alliance 5) Sandhills Upland Prairie V.A.5.N.a.3 Andropogon hallii herbaceous alliance. 6) Lowland Tallgrass Prairie V.A.5.N.a.1 Andropogon gerardii - (Calamagrostis canadensis, Panicum virgatum) herbaceous alliance V.A.5.N.j.11 Spartina pectinata temporarily flooded herbaceous alliance 7) Upland Tallgrass Prairie V.A.5.N.a.2 Andropogon gerardii - (Sorghastrum nutans) herbaceous alliance 8) Little Bluestem-Gramma Mixedgrass Prairie V.A.5.N.c.20 Schizachyrium scoparium - Bouteloua curtipendula herbaceous alliance V.A.5.N.c.29 Hesperostipa comata - Bouteloua gracilis herbaceous alliance 9) Western Wheatgrass Mixedgrass Prairie V.A.5.N.c.27 Pascopyrum smithii herbaceous alliance 10) Western Shortgrass Prairie V.A.5.N.e.9 Bouteloua gracilis herbaceous alliance 11) Barren/Sand/Outcrop VII.A.1.N.a.6 Open cliff sparse vegetation alliance VII.A.1.N.a.8 Rock outcrop sparse vegetation alliance VII.C.3.N.b.7 Large eroding bluffs sparse vegetation alliance 12) Agricultural Field 13) Open Water 14) Fallow Agricultural Field 15) Aquatic Bed Wetland V.A.5.N.c.27 Pascopyrum smithii intermittently flooded herbaceous alliance V.A.5.N.j.5 Distichlis spicata - (Hordeum jubatum) temporarily flooded herbaceous alliance V.A.5.N.j.12 Polygonum spp. - Echinochloa spp. temporarily flooded herbaceous alliance V.C.2.N.a.14 Potamogeton spp. - Ceratophyllum spp. - Elodea spp. permanently flooded herbaceous alliance 16) Emergent Wetland V.A.5.N.j.5 Distichlis spicata - (Hordeum jubatum) temporarily flooded herbaceous alliance V.A.5.N.k.33 Typha spp. - (Schoenoplectus spp., Juncus spp.) seasonally flooded herbaceous alliance V.A.5.N.k.53 Carex pellita seasonally flooded herbaceous alliance V.A.5.N.l.6 Schoenoplectus pungens semipermanently flooded herbaceous alliance V.A.5.N.l.9 Typha (angustifolia, latifolia) - (Schoenoplectus spp.) semipermanently flooded herbaceous alliance V.A.5.N.m.19 Carex spp. - Typha spp. saturated herbaceous alliance 17) Riparian Shrubland III.B.2.N.d.20 Symphoricarpos occidentalis temporarily flooded shrubland alliance V.A.5.N.m.20 Carex pellita - (Carex nebrascensis) - Schoenoplectus spp. saturated herbaceous alliance VII.C.2.N.c.1 Sand flats temporarily flooded sparse vegetation alliance 18) Riparian Woodland I.B.2.N.d.15 Populus deltoides temporarily flooded forest alliance II.B.2.N.a.20 Quercus macrocarpa woodland alliance II.B.2.N.a.29 Fraxinus pennsylvanica - (Ulmus Americana) woodland alliance II.B.2.N.b.4 Populus deltoides temporarily flooded woodland alliance 19) Low Intensity Residential 20) High Intensity Residential/Commercial/Industrial/Transportation
This dataset serves as an input to the Nebraska Gap Analysis vertebrate wildlife distribution modeling process.
U.S. Geological Survey (USGS) EROS Data Center, Unknown, Landsat TM Scene: University of Nebraska, Center for Advanced Land Management Information Services (CALMIT), Lincoln, NE 68588.
CALMIT, 2000, Delineation of 1997 Land Use Patterns for the Cooperative Hydrology Study in the Central Platte River Basin.
U.S. Fish & Wildlife Service, National Wetlands Inventory, 1992, National Wetlands Inventory.
University of Nebraska, Center for Advanced Land Managemnet In, 2005, The Nebraska Gap Analysis Final Report.
See the Nebraska Gap Analysis Project Final Report for details of the accuracy assessment.
Challenging the land cover map with five collections of field observations total 1262 points yielded an overall accuracy of 35.3% and Cohen's Khat of 0.267 and Khat Z-score of 16.93. Using area to weight classes differentially, an overall accuracy of 51.4% is achieved. The field data used in these accuracy assessments were not collected in an appropriately random fashion and not all of the land cover classes were proportionally sampled. To address some of these issues, an aggregation of the land cover classes was performed and the assessment were redone.
area-weighted AA on aggregated classes: overall accuracy = 72.7% total land area = 200,371 km2 producer's users' %land accuracy accuracy area Woodlands 0.149 0.325 2.96% Grasslands 0.868 0.776 53.92% Shrublands 0.002 0.071 0.91% Wetlands 0.051 0.350 2.04% Anthropolands 0.547 0.594 40.17%
Not applicable for raster data
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- These data are not to be used at scales greater that 1:100,000. Users should consult the NE-GAP final report for complete definitions of appropriate uses. Users can consult The National Gap Analysis webiste for further information <http://www.gap.uidaho.org>
|Data format:||Size: 71.648|
Although these data have been processed successfully on a computer system by NE-GAP, no warranty expressed or implied is made regarding the accuracy or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. It is strongly recommended that these data are directly acquired from a NE-GAP server and not indirectly through other sources which may have changed the data in some way. It is also strongly recommended that careful attention be paid to the content of the metadata file associated with these data. NE-GAP shall not be held liable for improper or incorrect use of the data described and/or contained herein. These data were compiled with regard to the following standards. Please be aware of the limitations of the data. These data are meant to be used at a scale of 1:100,000 or smaller (such as 1:250,000 or 1:500,000) for the purpose of assessing the conservation status of vertebrate species and vegetation types over large geographic regions. The data may or may not have been assessed for statistical accuracy. Data evaluation and improvement may be ongoing. NE-GAP makes no claim as to the data's suitability for other purposes. This is writeable data which may have been altered from the original product if not obtained from a designated data distributor