Andrew E. LaMotte Michael E. Wieczorek 2010 Version 1 raster digital data Data Series DS-587A Baltimore, Maryland U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?impv01_1 This 30-meter resolution data set represents the imperviousness layer for the conterminous United States for the 2001 time period. The data have been arranged into four tiles to facilitate timely display and manipulation within a Geographic Information System, browse graphic: nlcd01-partition. The National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). One of the primary goals of the project is to generate a current, consistent, seamless, and accurate National Land Cover Database (NLCD) circa 2001 for the United States at medium spatial resolution. For a detailed definition and discussion on MRLC and the NLCD 2001 products, refer to Homer and others (2004) and http://www.mrlc.gov/mrlc2k.asp.. The NLCD 2001 was created by partitioning the United States into mapping-zones. A total of 68 mapping-zones browse graphic: nlcd01-mappingzones.jpg were delineated within the conterminous United States based on ecoregion and geographical characteristics, edge-matching features, and the size requirement of Landsat mosaics. Mapping-zones encompass the whole or parts of several states. Questions about the NLCD mapping zones can be directed to the NLCD 2001 Land Cover Mapping Team at the USGS/EROS, Sioux Falls, SD (605) 594-6151 or mrlc@usgs.gov. To provide complete, current, and consistent public domain information of national land use and land cover. This national (conterminous United States) data set was developed for use by the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. NAWQA uses land-use data to assess land-use change, such as urban development and loss of agricultural lands as well as to allocate nutrient and pesticide loads to particular land-use categories. The data is stored in four tiles (IMPV01_1, IMPV01_2, IMPV01_3, IMPV01_4) browse graphic: nlcd01-partitions.jpg to allow for storage using the ArcInfo Workstation GRID data model, which cannot support files larger than 2.1 gigabytes. Each tile has been stored as a gzipped ARCTAR file. To extract the ArcInfo Workstation GRID from the .tgz archive file use WINZIP, TARARC, or the following commands: "gunzip tilename.tgz" then "tar xvof tilename.tar". Questions about the NLCD mapping of any zone can be directed to the NLCD 2001 Land Cover Mapping Team at the USGS's Earth Resources Observation and Science (EROS) Center, Sioux Falls, SD by telephone (605) 594-6151 or by email (mrlc@usgs.gov). The method employed to map percent imperviousness for NLCD 2001 consists of three key steps: deriving reference data of imperviousness from the high spatial resolution images, calibrating density prediction models using reference data and Landsat spectral bands, and extrapolating the developed models spatially to map per-pixel imperviousness. This method is described in detail in Yang and others (2003). The development of training data for impervious estimation is documented in each mapping-zone's metadata file. Each downloadable multi-zone image layer browse graphic: nlcd01-multizones.jpg is comprised of merged multiple mapping-zones browse graphic: nlcd01-mappingzones. Each mapping-zone has its own metadata that can be found in the appropriate mapping-zone metadata directory that is created when the downloaded multizone file is decompressed. The metadata for mapping-zone 01 would be located under the directory area1_landcover_metadata\zone1_impervious_meta_web_final (where "area1" is the same as "Multi-zone 1" and "zone1" is "mapping-zone 01"). The organization of multi zones and mapping-zones for TILE 1 is as follows: Multi-zone 1 contains mapping-zones 01, 02, 07, 08, 09; Multi-zone 2 contains mapping-zones 03, 04, 05, 06, 12; Multi-zone 3 contains mapping-zones 10, 18, 19, 20, 21; Multi-zone 4 contains mapping-zones 16, 17, 22, 23, 28; Multi-zone 6 contains mapping-zones 29, 30, 31, 39, 40; Multi-zone 7 contains mapping-zones 27, 33; Multi-zone 9 contains mapping-zone 38. Original Data Creation Listing: Multi-zone 1 Mapping-zone 01: USGS, Space Imaging LLC. Mapping-zone 02: USGS, Space Imaging LLC. Mapping-zone 07: USGS, Sanborn Mapping Company. Mapping-zone 08: Earth Satellite Corporation. Mapping-zone 09: Earth Satellite Corporation. Multi-zone 2 Mapping-zone 03: USGS, Earth Satellite Corporation. Mapping-zone 04: USGS, Earth Satellite Corporation. Mapping-zone 05: USGS, USGS EROS Landcover Team. Mapping-zone 06: USGS, Sanborn Mapping Company. Mapping-zone 12: USGS, Earth Satellite Corporation. Multi-zone 3 Mapping-zone 10: USGS, Earth Satellite Corporation. Mapping-zone 18: USGS, Earth Satellite Corporation. Mapping-zone 19: USGS, Earth Satellite Corporation. Mapping-zone 20: USGS, MDA Federal Inc. Mapping-zone 21: USGS, Earth Satellite Corporation. Multi-zone 4 Mapping-zone 16: USGS, USDA Forest Service. Mapping-zone 17: USGS, Sanborn Mapping Company. Mapping-zone 22: USGS, MDA Federal Inc. Mapping-zone 23: USGS, Sanborn Mapping Company. Mapping-zone 28: USGS, Sanborn Mapping Company. Multi-zone 6 Mapping-zone 29: USGS, Sanborn Mapping Company. Mapping-zone 30: USGS, MDA Federal Inc. Mapping-zone 31: USGS, MDA Federal Inc. Mapping-zone 39: USGS, MDA Federal Inc. Mapping-zone 40: USGS, MDA Federal Inc. Multi-zone 7 Mapping-zone 27: USGS, Sanborn Mapping Company. Mapping-zone 33: USGS, Sanborn Mapping Company. Multi-zone 9 Mapping-zone 38: USGS, Sanborn Mapping Company. 2001 publication date Complete As needed -128.307900 -98.182478 51.834455 36.820901 None National Water-Quality Assessment NAWQA land cover land use National Land Cover Data Set NLCD Inlandwaters Imperviousness None Conterminous United States None Users should refer to the metadata for each mapping zone for use constraints that may be unique to each zone. Andrew LaMotte U.S. Geological Survey mailing and physical address

5522 Research Park Drive

Baltimore Maryland 21228 USA 443-498-5549 443-498-5510 alamotte@usgs.gov Monday through Friday, 9:00 am - 5:00 pm EST email http://water.usgs.gov/GIS/browse/impv01_1.jpg Imperviousness Layer Tile 1, Northwest United States JPG U. S. Geological Survey Microsoft Windows Vista Version 6.1 (Build 7600) ; ESRI ArcCatalog 9.3.1.3500 U.S. Geological Survey 2001 raster digital data http://eros.usgs.gov/#/Find_Data/Products_and_Data_Available/NLCD_92 U.S. Geological Survey Nakagaki, Naomi Price, Curtis V. Falcone, James A. Hitt, Kerie J. Ruddy, Barbara C. 2007 1.0, 2005 Raster digital data http://water.usgs.gov/lookup/getspatial?nlcde92 U.S. Geological Survey Hitt, Kerie J. 2006 Version 3, March 2006 (Replaces Version 2, Sept 2005) Raster digital data Yang, L., Huang, C., Homer, C., Wylie, B., and Coan, M. 2003 v. 29: no. 2, p. 230-240. Homer, C., Huang, C., Yang, L., Wylie, B., and Coan, M. 2004 v. 70, no. 7, p. 829 - 840 http://www.mrlc.gov/publications.php ESRI feature type: Geometry, Topology Complete for conterminous United States Multi-zone zipped image files were downloaded from the MRLC multi-zone web site http://www.mrlc.gov/index.asp on May 21, 2007. Image header files were then built partly based on the format supplied by the USGS LCI (Land Cover Institute) from the web site http://landcover.usgs.gov/faq.php; the exact parameters are shown below. Left longitude and top latitude extents were obtained for each image by reading the source information in ArcGIS. Images were then converted to raster data sets using the IMAGEGRID command in Arc workstation. The command PROJECTDEFINE was then applied to each multi-zone grid for proper display and projection definition. The resulting raster data sets were then merged together using the national tile configuration previously established by NAWQA for NLCD, NLCDe, and NLCDeP. Tiles were assembled by using the SETWINDOW command with the NAWQA tiles as SNAP grids for proper alignment with the other national data sets. ****************************************************************************************** Tile 1 contains all or parts of the following Multi zones and their respective mapping-zones. Multi-zone 1: mapping-zones 01, 02, 07, 08, 09; Multi-zone 2: mapping-zones 03, 04, 05, 06, 12; Multi-zone 3: mapping-zones 10, 18, 19, 20, 21; Multi-zone 4: mapping-zones 16, 17, 22, 23, 28; Multi-zone 6: mapping-zones 29, 30, 31, 39, 40; Multi-zone 7: mapping-zones 27, 33; Multi-zone 9: mapping-zone 38. ****************************************************************************************** Example of a header file for Multi-zone 1 BYTEORDER M LAYOUT img NROWS 31326 NCOLS 26024 NBANDS 1 NBITS 8 SKIPBYTES 0 ULXMAP -2303835 ULYMAP 3180435 XDIM 30 YDIM 30 ****************************************************************************************** 2007 Andrew LaMotte U.S. Geological Survey mailing and physical address

5522 Research Park Drive

Baltimore Maryland 21228 USA 443-498-5549 443-498-5510 alamotte@usgs.gov Monday through Friday, 9:00 am - 5:00 pm EST email Raster Grid Cell 44167 73167 1 Albers Conical Equal Area 29.500000 45.500000 -96.000000 23.000000 0.000000 0.000000 row and column 30.000000 30.000000 meters North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 impv01_1.vat Value attribute table. ESRI - Entity Attribute Overview Description. Rowid Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Value Percent Imperviousness NLCD 2001 0 100 Percentage Count Count is the total number of cells in a grid for each unique value. Calculated Sequential unique whole numbers that are automatically generated. 100 Derived number of grid cells. As needed U.S. Geological Survey Ask USGS -- Water Webserver Team mailing address

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Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://water.usgs.gov/user_feedback_form.html Downloadable Data Although this data set has been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology. ARC INFO GRID 1.0 gzipped arctar file Percentage imperviousness raster data for northwest quadrant of the United States gunzip then use tar -xvf IMPV01_1.tar, or use WinZip 137,365 http://water.usgs.gov/GIS/dsdl/impv01_1.tar.gz Not specified None, this data set is provided by the USGS as a public service. 2010 U.S. Geological Survey Ask USGS Water Webserver Team mailing address

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Reston Virginia 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+impv01_1 Monday through Friday, 9:00 am - 5:00 pm EST FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998