GIS Details

Sample of At-risk Species Occurrence Records (Biotics_Sample.zip, 39kB, 9 September 2005). Feature type: polygons. Coordinate System: UTM Zone-11 meters on the North American Datum of 1927 (NAD27). NOTE: sample data have been "fuzzed" to obscure true locations. Feature count: 8100+ observed areas (14 in sample), along with the 7600+ combined-precision occurrence records (8 in sample) they represent. Completeness of data: the full data set is always a work-in-progress, with records being digitized, revised, and/or added daily as new or backlogged data are processed. Extracted data sets become static as of the date on which they are provided. Currency of data: 1844 up to the present in the full data set, or earlier depending on source information and data entry backlog for particular species. Scale at which data are believed to meet National Map Accuracy Standards: 1:24,000. Scope, origin and production of data: the full data set includes all reports known to us of at-risk or watch-list species and plant communities processed into our databases (however, the data can never be assumed to represent a complete survey of any area or species). Species observations are digitized as polygons, lines, or points, either from the original survey data, or based on our best professional interpretation of data supplied by others or researched in museums or the literature. Until updated, the data converted from our old BCD data system remain as representative point coordinates, minimally buffered to create polygons. See our working Biotics Metadata for further information and description of the data set. See our Data Request Form to request current at-risk species occurrence records for any area of Nevada. 

Nevada Vegetation Synthesis Map (March 2008) (synthmap08.zip, 69,967kB, 11 March 2008). Feature type: ArcGRID. Completeness of data: 100% of Nevada plus edges of adjacent states. Currency of data: various, up to winter 2007/08; updates are expected in the future. Scale at which data are believed to meet National Map Accuracy Standards: 1:100,000 in most areas. Key attributes: International Vegetation Classification (IVC) types at ecological system, alliance, and association levels, with additional fields indicating the IVC level, IVC code, and origin of the data. See the accompanying documentation on our Library page. An ArcGIS layer file is included for convenient display symbology. The data table is included as an Excel file as well. NOTE: the goal of the Synthesis Map is to provide the most accurate existing vegetation map possible while also improving thematic resolution when possible. 

Nevada Vegetation Project Index (March 2008) (vegindex.zip, 3947kB, 11 March 2008). Feature type: Shapefile (polygons). Feature count: 37. Completeness of data: winter 2007/08; updates are expected in the future. Scale at which data are believed to meet National Map Accuracy Standards: 1:100,000. Scope, origin and production of data: In the course of assembling the 2008 Nevada Vegetation Synthesis Map (above), vegetation mapping project data were manipulated to provide boundaries of project extents. These boundaries were combined into VegProjIdx.shp to provide an index of what projects have occurred over a given area. After opening the layer into ArcGIS, use of the Identify tool should provide a list of vegetation mapping projects for any area selected. This is done by allowing boundary polygons to overlap, so caution should be used if the shapefile is manipulated. 

Cheatgrass (Bromus tectorum) Estimated Percent Cover (December 2003) (brtegrid.zip, 55,789kB, 5 January 2004) Feature type: Arc Grid. Completeness of data: 46.4% of Nevada (north-central portion). Currency of data: effectively spring 2001. Scale at which data are believed to meet National Map Accuracy Standards: 1:100,000. Key attributes: cell values 0-100 refer to percent cheatgrass cover, 101 = cultivated fields, 102 = urban areas. See full metadata for more information; for full interpretation of the data, also see the accompanying report on our Library page. NOTE: in order to restore the correct structure of the GRID data, be sure to turn on the option to preserve directory structure ("Use folder names" in WinZip) when extracting the files, and be sure to extract ALL files at once. 

Annual Grass Index of Nevada (March 2006) (anngrass.zip, 158,463kB, 5 June 2006) Feature type: Arc Grid. Completeness of data: 100% of Nevada plus edges of adjacent states. Currency of data: effectively spring 2004/2005. Scale at which data are believed to meet National Map Accuracy Standards: 1:100,000 in most areas. Key attributes: cell values 0-100 refer to percent annual grass cover.  Negative values indicate no data. See full metadata for more information; for full interpretation of the data, also see the accompanying report on our Library page. NOTE: in order to restore the correct structure of the GRID data, be sure to turn on the option to preserve directory structure ("Use folder names" in WinZip) when extracting the files, and be sure to extract ALL files at once. 

Annual Grass Index of the Owyhee Uplands (March 2007) (anngrowy.zip, 33,509kB, March 2007) Feature type: Arc Grid. Completeness of data: 100% of Owyhee Uplands, Nevada, Idaho, and Oregon, plus 25 km buffer. Currency of data: based on spring 2006 field and spectral data. Scale at which data are believed to meet National Map Accuracy Standards: 1:100,000 in most areas. Key attributes: cell values 0-100 refer to percent annual grass cover.  Negative values indicate no data. See full metadata for more information; for full interpretation of the data, also see the accompanying report on our Library page. An ArcGIS layer file is included in the download for the display symbology. NOTE: in order to restore the correct structure of the GRID data, be sure to turn on the option to preserve directory structure ("Use folder names" in WinZip) when extracting the files, and be sure to extract ALL files at once. 

Minor Phytogeographic Regions of Nevada(phytoreg.zip, 297kB, 19 November 2001). Feature type: polygons. Feature count: 27. Completeness of data: Finished, but subject to future revision if deemed desirable. Currency of data: 1998. Scale at which data are believed to meet National Map Accuracy Standards: 1:100,000. Scope, origin and production of data: These polygons were created to represent our perceptions of floristically and physiographically cohesive regions of Nevada. Using Plant Geography of the Intermountain Region (by Noel H. Holmgren, 1972, pages 77-161 in Intermountain Flora, vol. 1, New York Botanical Garden, Bronx) as an initial guide, boundaries were digitized on-screen over the 1998 GAP Land Cover 30-m grid data at between 1:50,000 and 1:100,000 display scale. Each region was visualized to encompass a similar overall mosaic of vegetational, floristic, geologic, topographic, and climatic features, using the GAP data as a tool, but also employing other data including personal knowledge of various portions of the state. Key attributes: UNIT_NAME.

Major Phytogeographic Regions of Nevada (ecomajor.zip, 109kB, 19 November 2001). Feature type: polygons. Feature count: 6. Completeness of data: Finished, but subject to future revision if deemed desirable. Currency of data: 1998. Scale at which data are believed to meet National Map Accuracy Standards: 1:100,000. Scope, origin and production of data: These polygons were created by combining polygons from the Minor Phytogeographic Regions of Nevada data set (see above) to represent our perceptions of the 5 major ecoregions found in Nevada. Key attributes: MAJOR_HOST.

National Wetlands Inventory (NWI-Nevada.zip, 11,090kB, February 2004). Feature type: points, lines, and polygons (3 layers). Completeness of data: finished, but subject to future revisions, corrections, or additions of data not currently known to us. Currency of data: ca. 2000. Scale at which data are believed to meet National Map Accuracy Standards: 1:250,000. Scope, origin, and production of data: These data were downloaded in 1:250k quadrangle blocks from the U.S. Fish and Wildlife Service, National Wetlands Inventory, in ca. 2002 and stitched together to provide statewide data layers for Nevada. In Feburary 2004 the wetland codes for the polygon layer were reclassified into a simple 3-category scheme for display in wetland related documents: vegetated wetlands, playas, and open-water. Further information on the National Wetlands Inventory is available at http://www.fws.gov/nwi/. Key attributes: ATTRIBUTE for all data, GROUP for the simplified classification of the polygon data. 

Lakes, Playas, and Other Water Bodies of Nevada (lake_100.zip, 2485kB, 20 March 2003). Feature type: polygons. Feature count: 2007. Completeness of data: features 98%+ present, about 80% checked, refined, and attributed. All features classified as "major" have been attributed as to name (if any) and type. All features south of about latitude 39°-40°N are finished. North of that, all feature boundaries have yet to be compared and potentially refined against current 1:100,000 DRG topographic maps, a few minor features may remain to be digitized, and most features classified as "minor" remain to be attributed as to name (if any) and type. As of March 2003, over 300 new minor features were added and completed, most from 1:24,000 source maps, to the western 1/3 of Nevada north of 37°N. Currency of data: varies depending on currency of source map data. Scale at which all data are believed to meet National Map Accuracy Standards: 1:100,000. Scope, origin, and production of data: When complete, these data will include all lakes, playas, reservoirs, major wetland areas, and other actual or potential water-body features depicted on current 1:100,000 topographic maps, plus some major and minor features depicted only on 1:24,000 topographic maps. Compilation started with downloaded digital line graph (DLG) hydrography data for Nevada. Polygons were built and cleaned from the line data using PC-ArcInfo, and then exported to shapefile format for further editing in ArcView. Spurious polygons (water-course anastomoses, etc.) were then removed by comparison with the original DLG data and with 1:100,000 paper topographic maps. The 1:100,000 DRG topographic maps covering Nevada were then reviewed on-screen in series from south to north and from east to west. Boundaries of DLG features were refined as needed, and all other mapped water-body features were digitized on-screen and attributed. In some case, major known water-body features were captured and/or further refined using 1:24,000 DRG topographic maps. Key attributes: NAME = mapped name of the feature, if any, TYPE = class of feature as assigned by the Nevada Natural Heritage Program, TYPE_CODE = numeric code (0=unassigned, 1-7=major features, 10=river section polygons, 11-17 = minor features) corresponding to each feature class. 

Place Names and Locations of Nevada (nvplaces.zip, 794kB, 19 November 2001). Feature type: points. Feature count: 26678. Completeness of data: unknown; the GNIS data appeared largely complete for Nevada when acquired, but an occasional feature has been added as individual 1:24,000 DRG topographic maps have been reviewed. Currency of data: obtained from GNIS in January 2000. Scale at which data are believed to meet National Map Accuracy Standards: 1:24,000. Scope, origin and production of data: The source data were downloaded in late 1999 from the U.S. Geological Survey's Geographic Names Information System (GNIS), and nominally represent all named features on 1:24,000 (or largest available scale) U.S.G.S. topographic maps in Nevada. See the GNIS online metadata for further information on scope, origin, and production. Feature coordinates were used with ArcView® to create a corresponding shapefile. Attribute fields representing location data already available to us as separate GIS data sets (such as map quadrangles, counties, etc.), or representing other data that we had no need or ability to interpret or use, were removed for compactness. A single field (see CLASS below) was then added and populated to provide a higher level of classification for the feature types included, to facilitate representation on map legends and other data uses. Key attributes: NAME = federally recognized name of the feature, CLASS = general feature class assigned by Nevada Natural Heritage Program, TYPE = specific feature class assigned by GNIS. 

7.5-minute (1:24,000) Map Quadrangles of Nevada and Bordering Areas (quad_075.zip, 186kB, 20 August 2003). Feature type: polygons. Feature count: 2793. Completeness of data: Complete except for some Arizona, Idaho, and Oregon quads, for which version year, stock number, and completion attributes are still missing. Currency of data: spatial data always current, name and date attributes as of 11 December 2001. Scale at which data are believed to meet National Map Accuracy Standards: 1:1. Scope, origin and production of data: The data include all 7.5 x 7.5 minute (1:24,000) map quadrangles in a rectangle completely containing Nevada plus one additional quadrangle row on the north and west, and were created exactly via automated means. An xBase-language computer program was written and compiled to generate PC-ArcInfo® SML code, which when run in turn generated all the arcs defining the quadrangle boundaries using exact coordinates at 7.5-minute intervals. The SML code also generated numeric quadrangle code attributes. Polygons were then built and cleaned from these lines, and vertices were densified to 2.5-minute intervals along all arcs. The resulting polygons were then exported to a shapefile, and attributes from U.S. Geological Survey digital index maps and map lists, downloaded in December 1999 and December 2001, were then selectively joined to add quadrangle names and other attributes. Key attributes: QUADNAME = the U.S.G.S. name of the map in a quadrangle, STATE = state in which all or a majority of the quadrangle lies, QUADCODE = the numeric code for each map assigned by the Nevada Natural Heritage Program, OHIO_INDEX = the equivalent alpha-numeric code for each map, PUBYEAR = most recent topographic edition, FIELDYEAR = year data most recently field-verified or checked, COMPLETION = status as Provisional or Final edition, STATE2 = state with the second largest area represented on the quadrangle, STATE3 = state with the third largest area represented on the quadrangle. 

15-minute (1:62,500) Map Quadrangles of Nevada and Bordering Areas (quad_015.zip, 56kB, 12 December 2001). Feature type: polygons. Feature count: 726. Completeness of data: features complete, name and date attributes in progress, 21% complete as of 11 December 2001, including all paper maps where at-risk species data are currently plotted. Currency of data: spatial data always current, name and date attributes based on 1989 U.S.G.S. catalog of published maps for Nevada. To our knowledge, no new maps or map editions have been produced at this scale in Nevada since 1989. Scale at which data are believed to meet National Map Accuracy Standards: 1:1. Scope, origin and production of data: The data include all 15 x 15 minute (1:62,500) map quadrangles in a rectangle completely containing Nevada plus one additional quadrangle row on the north and west. The spatial data and numeric code fields were derived directly from the 7.5-minute data set (see above) by progressively combining polygons. Name and date attributes were hand-entered from the 1989 U.S.G.S. Catalog of Published Maps for Nevada. Key attributes: QUADCODE = the numeric code for each map assigned by the Nevada Natural Heritage Program, QUADNAME = the U.S.G.S. name of the map in a quadrangle, PUBYEAR = most recent topographic edition, DMAYEAR = most recent 1:50,000 edition published by the Defense Mapping Agency. 

1 x 0.5-degree (1:100,000) Map Quadrangles of Nevada and Bordering Areas (quad_100.zip, 25kB, 12 December 2001). Feature type: polygons. Feature count: 105. Completeness of data: Complete except for some Idaho and Oregon quads, for which version year and stock number attributes are still missing. Currency of data: spatial data always current, name and date attributes as of 11 December 2001. Scale at which data are believed to meet National Map Accuracy Standards: 1:1. Scope, origin and production of data: The data include all 1 x 0.5 degree (1:100,000) map quadrangles in a rectangle completely containing Nevada plus one additional quadrangle row on the north and west. The spatial data and numeric code fields were derived directly from the 7.5-minute data set (see above) by progressively combining polygons. Attributes from U.S. Geological Survey digital index maps and map lists, downloaded in December 1999 and December 2001, were then selectively joined to add quadrangle names and other attributes. Key attributes: QUADNAME = the U.S.G.S. name of the map in a quadrangle, PUBYEAR = most recent topographic edition, FIELDYEAR = year data most recently field-verified or checked, SM_PUB = most recent surface-management edition, SM_CURRENT = year surface-management data considered current. 

1 x 2-degree (1:250,000) Map Quadrangles of Nevada and Bordering Areas (quad_250.zip, 14kB, 12 December 2001). Feature type: polygons. Feature count: 32. Completeness of data: Complete except for some Idaho and Oregon quads, for which attributes remain to be populated. Currency of data: always current. Scale at which data are believed to meet National Map Accuracy Standards: 1:1. Scope, origin and production of data: The data include all 1 x 2 degree (1:250,000) map quadrangles in a rectangle completely containing Nevada plus one additional quadrangle row on the north and west. The spatial data and numeric code fields were derived directly from the 7.5-minute data set (see above) by progressively combining polygons. Attributes from U.S. Geological Survey digital map lists, downloaded in December 2001, were then selectively joined to add quadrangle names and other attributes. Key attributes: QUADNAME = the U.S.G.S. name of the map in a quadrangle, PUBYEAR = most recent topographic edition, FIELDYEAR = year data most recently field-verified or checked. 

2.5-minute Map Quadrangle Grid Tics for Nevada and Bordering Areas (quadtics.zip, 229kB, 19 November 2001). Feature type: points. Feature count: 24820. Completeness of data: Finished and complete. Currency of data: always current. Scale at which data are believed to meet National Map Accuracy Standards: 1:1. Scope, origin and production of data: The data include all points at 2.5-minute intervals of latitude and longitude, corresponding to the 2.5-minute grid tics found on standard 7.5 x 7.5 minute (1:24,000) maps, in a rectangle completely containing Nevada plus one additional row on the west, north, and east, and were created exactly via automated means. An xBase-language computer program was written and compiled to generate PC-ArcInfo® SML code, which when run in turn generated all the points using exact coordinates, plus the numeric quadrangle code attributes. The resulting points were then exported to a shapefile. Key attributes: QUADCODE = the numeric code for the 7.5-minute map quadrangle to which each tic is assigned by the Nevada Natural Heritage Program. 

Major Sand Dunes of Nevada (sandunes.zip, 236kB, 19 November 2001). Feature type: polygons. Feature count: 132. Completeness of data: very incomplete, compilation in progress. Most relevant features south of latitude 39°-40°N have been captured, and attributes populated when known. North of that, only features visible on the 1998 GAP Land Cover 30-m grid data have been captured in rough form, and review, capture, refinement, and attribution of mapped features remains to be done. Currency of data: 1967-1997, varies depending on currency of source map data. Scale at which data are believed to meet National Map Accuracy Standards: 1:100,000. Scope, origin and production of data: When complete, these data will include all sand dune features depicted on current 1:100,000 topographic maps, plus some major features depicted only on 1:24,000 topographic maps. Compilation began by on-screen capture of sand dune areas depicted in the 1998 Nevada GAP Land Cover 30-m grid data. The 1:100,000 DRG topographic maps covering Nevada were then reviewed on-screen in series from south to north and from east to west. Boundaries of GAP-indicated features were refined, and all other mapped dune features were digitized on-screen and attributed. In some cases, major known dune features were captured and/or further refined using 1:24,000 DRG topographic maps. Key attributes: DUNE_NAME = name of dune feature or dune system as mapped or as assigned by the Nevada Natural Heritage Program, MAPYEAR = year the features on the source map were last field-checked. 

SOFTWARE

Information common to all software: The software below, downloadable from our web site, is provided as-is with no warranty or support of any kind. Download and use of any or all of this software is at the user's sole and voluntary risk! This software is in the public domain, and may not be sold commercially. Downloadable software and documentation are compressed as standard ZIP archives (.zip), and require appropriate software to extract the component files. To download: right-click on the appropriate download link, and choose "save file as", "save target as", or whatever equivalent option your browser provides, and select a location on your hard drive. To extract files: place the .zip archive in an otherwise empty folder, then invoke your favorite ZIP software to extract the files. Files with extension .avx must be placed in the EXT32 folder of your ArcView® 3.x installation to make them available for loading into an ArcView® 3.x project. (In a project, choose File, Extensions, then find the name of the extension you wish to load, place a check mark next to it, and OK the window. Additional menus, buttons, and/or tools will then appear in various document windows.)  Extensions for other platforms will need to be installed according to the platform software's instructions.

NVTools version 4.0e for ArcView® 3.x (nvtools.zip, 107kB, 7 June 2012). Adds various menus, buttons, and tools to the View, Table, and Project windows. These utilities help the user more efficiently view, select, create, edit, update, clean up, synthesize, copy, and convert spatial and tabular data within and between data sets; create and compute attribute fields for area, perimeter, length, point coordinates, and Grid elevation data; plot and edit great-circle vectors and calculate rhumb line vectors; select, manipulate, and change the display of multiple themes in a View; refresh, copy, recenter, and change the coordinate-display units and precision of Views, and port projects to different screen sizes. The function(s) that extract Grid data are only enabled when ESRI's Spatial Analyst extension is also loaded. Especially versatile or useful are functions named Append/Convert with Attributes, Replace/Convert Shapes/Attributes, Calculate From Grid, Append From Table, and Copy Cell Value. Some of the added buttons and tools simply make existing, frequently accessed ArcView® menu functionality more readily accessible. For further information, see the on-line documentation, or download the extension and documentation.

GMSRead version 1.1 for ArcView® 3.x (gmsread.zip, 11kB, 3 March 2003). Adds a G button to the Project window. When pressed, the user may choose one or more Garmin® MapSource® data export files (*.txt) to load into a new Table of point data (*.dbf; defaults to same name and location) in the Project, for use as an Event Theme in ArcView.  All saved data attributes are loaded into appropriate fields, and coordinate fields are further converted to ArcView-readable format.  Attributes allow selection of point sets associated with particular tracks or other GPS features gathered.  Functions available in the separate NVTools extension facilitate conversion of such point sets to lines, polygons, or averaged coordinates.  For further information, see the on-line documentation, or download the extension and documentation.

A General Toolbox for ArcView® 3.x (a_general_toolbox.zip, 8 kB, 12 December 2002).  This extension contains a few simple, handy functions for views and layouts.  For views: PutDot, toggling between GCS and UTM (zone 11), converting coordinate pairs between those two projections, run ‘Script1’ and ‘Script2’, redraw view, and copy view.  For layouts: graphics flip, mirror, distribute horizontally, distribute vertically, redraw layout, copy layout, and run ‘Script1’ and ‘Script2’.  The most popular in our office has been ‘PutDot’, which places a graphic dot of your chosen color at the coordinates you input in UTM (any zone, though only 11 has been tested), decimal degrees, decimal minutes, or decimal seconds.  You may also have the view re-centered on the dot at the scale of your choice and the coordinates may also be written as text graphics.  Lastly, the function remembers your settings from one use to the next.  The extension provides everything via a new menu, plus there is a button added for ‘PutDot’.

GPS Realtime beta for ArcView® 3.2 (GPSrealtimebeta.zip, 41 kB, 25 September 2001).  This is an ArcView® extension (3.2, presumably 3.3) that will place a ‘moving dot’ into a View.  A GPS data window is also displayed.  The program is functional, but buggy.  There are currently no plans to update it, as ESRI provides an equivalent free extension for ArcMap.  One bug can cause a crash that leaves the DLL running, so you need to reboot the computer before you can get it running again.  When installing, the AVX and DLL files should both go into your EXT32 folder.

ExtractPoints version 1.03 for ENVI® + IDL® (NNHPExtractPoints1_03.zip, 7.2 MB, 1 March 2006).  This will extract data from a raster layer at points specified by a vector point layer (EVF format, easily converted in ENVI® from SHP format).  Data is output to a text file of your choice in a comma-separated-values (CSV) format.  For details, see the README file.

Landsat 7 Converter for Windows (ls7conv.zip, 34kb, 2 July 2001). This is a simple windows-based program for converting NLAPS format Landsat rasters to BIL. This was written because ArcView® 3.x Image Analysis did not load the NLAPS files, even though it claims to.  If you are using ArcView® 3.x it is possible to load the BIL images - look up BIL in the help files - it may require Spatial Analyst. In ArcView® 8.2 (and presumably higher), you can load the BIL directly as a raster without the addition of Spatial Analyst. You can also use ArcCatalog® to convert the BIL to other formats. Many GIS and Remote Sensing programs will accept BIL. Projection information is lost with the converter, so you may need to edit the header files manually to add that back in (search help files and the internet for ‘BIL’ or ‘GeoTiff’ along with 'header' or "World File" to get started).