Identification_Information: Citation: Citation_Information: Originator: Hitt, Kerie J. Publication_Date: 20080612 Title: NAWQA GIS ancillary data: National Land Cover Data 2001 (NLCD 2001) for 500-m buffers around ground water sampling sites Online_Linkage: http://water.usgs.gov/nawqa-only/gw.html Description: Abstract: This data set consists of NLCD 2001 land use percentages for 500-meter buffers around NAWQA ground water sampling sites. The land use data is from the "raw" NLCD 2001 30-m data. The sampling sites are from the NAWQA data warehouse. Purpose: This is one of the ancillary GIS data layers developed to characterize NAWQA sampling sites for national synthesis of water-quality data. The data might be used to evaluate the strengths and weaknesses of NLCD 2001 and whether to use NLCD 2001 as the "standard" land use data set for cycle 2 of the NAWQA program. Since this data was obtained, the NLCD 1992-2001 Retrofit Change Product became available. Supplemental_Information: The NLCD 2001 input data set did not include Alaska and Hawaii, so sites in Cook and Oahu have "no data." Some sites in Puget Sound fall in Canada and do not have NLCD 2001 data. Time_Period_of_Content: Time_Period_Information: Multiple_Dates/Times: Single_Date/Time: Calendar_Date: 2001 Single_Date/Time: Calendar_Date: 2004 Currentness_Reference: The data set is intended to represent conditions from about 2001 to 2004. Status: Progress: Complete Maintenance_and_Update_Frequency: NAWQA sampling sites are added as their locations become available. Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -125 East_Bounding_Coordinate: -66 North_Bounding_Coordinate: 50 South_Bounding_Coordinate: 24 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Ground water Theme_Keyword: Land use Theme_Keyword: Land cover Theme_Keyword: NLCD Theme_Keyword: NLCD 2001 Theme_Keyword: MRLC Theme_Keyword: National land cover data Theme_Keyword: Water quality Access_Constraints: The data set is for internal USGS access only. Use_Constraints: The data set is for internal USGS use only. Data_Quality_Information: Logical_Consistency_Report: none Completeness_Report: none Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Colin Homer Originator: Chengquan Huang Originator: Limin Yang Originator: Bruce Wylie Originator: Michael Coan Publication_Date: 200407 Title: Development of a 2001 National Land-Cover Database for the United States Edition: 1 Geospatial_Data_Presentation_Form: raster digital data Series_Information: Series_Name: Photogrammetric Engineering & Remote Sensing Journal of the American Society for Photogrammetry and Remote Sensing Issue_Identification: v. 70, no. 7, July 2004, pp. 829-840 Type_of_Source_Media: digital files Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2001 Source_Currentness_Reference: Ground condition Source_Citation_Abbreviation: NLCD 2001 Source_Contribution: This source provided "raw" NLCD 2001 30-meter resolution land cover. NLCD 2001 data was downloaded in May 2007 and was assembled into 4 grid tiles by Andrew Lamotte. NAWQA has not "enhanced" this data set with any ancillary data. >NLCD 2001 LANDCOVER CODES AND DESCRIPTIONS >----------------------------------------------- >11 Open Water >12 Perennial Ice/Snow >21 Developed, Open Space >22 Developed, Low Intensity >23 Developed, Medium Intensity >24 Developed, High Intensity >31 Barren Land (Rock/Sand/Clay) >41 Deciduous Forest >42 Evergreen Forest >43 Mixed Forest >52 Shrub/Scrub >71 Grasslands/Herbaceous >81 Pasture/Hay >82 Cultivated Crops >90 Woody Wetlands >95 Emergent Herbaceous Wetlands >-9 Missing data* >* added classification to fill in null data values considered within 2001 county boundaries Source_Information: Source_Citation: Citation_Information: Originator: Curtis Price Originator: Jessica Thompson Publication_Date: 20080429 Title: NAWQA sampling points (NAWQAPT) Edition: April 2008 Geospatial_Data_Presentation_Form: vector digital data Type_of_Source_Media: digital files Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20080429 Source_Currentness_Reference: current Source_Citation_Abbreviation: NAWQAPT Source_Contribution: The location of all of the NAWQA sampling sites as of publication date. Process_Step: Process_Date: 200806 Process_Description: The basic procedure was to create a 500-m radius circular buffer of NLCD 2001 land use around each NAWQA sampling site, then calculate what fraction of the total buffer is represented by each land use category within the buffer. Data processing occurs at 30 meters resolution. The grid representing the 500-m buffer of land use around the site was created using GRID SELECTCIRCLE. The location of each site in NAWQAPT (xcoord and ycoord) forms the center of the buffer. The land use fraction for each land use category (AREAF) is computed as the area of each land use in the buffer divided by the total area of the buffer. The land use percentage is AREAF * 100. The NLCD 2001 by buffer was derived from the county/NLCD 2001 land use weight table (GWBUF_FIPSLU.AWT) by summing the area fractions (AREAF) by unique occurrences of Station id (AREAID) and land use (NLCD 2001). >FREQUENCY GWBUF_NLCD01_FIPSLU.AWT GWBUF_NLCD01_1 >Frequency items: AREAID, NLCD01 >Summary items: AREAF, AREAKM2 Processing routines are from the NAWQA area characterization toolbox. Process_Step: Process_Date: 200806 Process_Description: Grouped the above results (multiple records for each AREAID) by AREAID. >GROUP2ROW GWBUF_NLCD01_1 GWBUF_NLCD01 AREAID NLCD01 AREAF NLCD 2001 numbers were multiplied by 100 and AREAF was multiplied by 100 and the name was changed to LUPCT (land use percent). The file structure now is one record for each STAID. Process_Step: Process_Date: 20080612 Process_Description: Processed NLCD 2001 using sites selected from NAWQAPT version 4/29/08. Instead of using all of the sites in NAWQAPT, only ground water (GW) sites were processed. The GW sites were selected using the GW network table and site TYPE as follows: First obtain all of the sites in the GW networks contained in the GW network table (nawqapt.gwnetc): >reselect nawqapt.net info keyfile nawqapt.gwnetc info sucode >reselect nawqapt points keyfile nawqapt.net info staid Then go back to get any points not selected that are coded as Ground Water TYPE: >asel nawqapt points TYPE = 'GW' This resulted in 9051 sites. Two sites needed for the Nutrients Circular were obtained from the Nutrients master data set: >STAID 335914102430001 >STAID 472522117054901 Of these 9053 sites, 93 fall in locations outside of the extent of NLCD 2001 in OAHU, COOK, and Canada (PUGT). Therefore these sites have no NLCD 2001 data. NLCD 2001 data now covers 8960 sites. Spatial_Data_Organization_Information: Indirect_Spatial_Reference: The data set is referenced by AREAID, the station id of the NAWQA sampling site. Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: The data set is organized by AREAID (station id). The fields are: >AREAID NAWQA station id >NLCD01_11 Percent of 500-m buffer comprised of Open Water >NLCD01_12 Percent of 500-m buffer comprised of Perennial Ice/Snow >NLCD01_21 Percent of 500-m buffer comprised of Developed, Open Space >NLCD01_22 Percent of 500-m buffer comprised of Developed, Low Intensity >NLCD01_23 Percent of 500-m buffer comprised of Developed, Medium Intensity >NLCD01_24 Percent of 500-m buffer comprised of Developed, High Intensity >NLCD01_31 Percent of 500-m buffer comprised of Barren Land (Rock/Sand/Clay) >NLCD01_41 Percent of 500-m buffer comprised of Deciduous Forest >NLCD01_42 Percent of 500-m buffer comprised of Evergreen Forest >NLCD01_43 Percent of 500-m buffer comprised of Mixed Forest >NLCD01_52 Percent of 500-m buffer comprised of Shrub/Scrub >NLCD01_71 Percent of 500-m buffer comprised of Grasslands/Herbaceous >NLCD01_81 Percent of 500-m buffer comprised of Pasture/Hay >NLCD01_82 Percent of 500-m buffer comprised of Cultivated Crops >NLCD01_90 Percent of 500-m buffer comprised of Woody Wetlands >NLCD01_95 Percent of 500-m buffer comprised of Emergent Herbaceous Wetlands >NLCD01_-9 Percent of 500-m buffer comprised of Missing data >SUM_LUPCT Sum of the percents of all the land use categories (approx. 100) Entity_and_Attribute_Detail_Citation: None Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Kerie Hitt Contact_Organization: USGS NAWQA Nutrients National Synthesis Contact_Address: Address_Type: Mailing address Address: 413 National Center City: Reston State_or_Province: VA Postal_Code: 20192 Country: USA Contact_Electronic_Mail_Address: kjhitt@usgs.gov Contact_Voice_Telephone: 703 648-6854 Contact_Instructions: Contact via email Distribution_Liability: USGS assumes no liability for the use of this data set. Metadata_Reference_Information: Metadata_Date: 20080612 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Kerie Hitt Contact_Organization: USGS NAWQA Nutrients National Synthesis Contact_Address: Address_Type: Mailing address Address: 413 National Center City: Reston State_or_Province: VA Postal_Code: 20192 Country: USA Contact_Electronic_Mail_Address: kjhitt@usgs.gov Contact_Voice_Telephone: 703 648-6854 Contact_Instructions: Contact via email Metadata_Standard_Name: Content standards for digital geospatial metadata Metadata_Standard_Version: FGDC-STD-001-1998