Rose L. Medina Thomas J. Lopes 2007 raster digital data Reston, VA U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?jnwra_v4n2_pzm1in Thomas J. Lopes Rose L. Medina 2007 document Journal of Nevada Water Resources Association Volume 4, Number 2 Reno, NV Nevada Water Resources Association http://www.nvwra.org/journal/vol4no2.asp This data set contains 1971-2000 mean annual precipitation estimates for west-central Nevada. This is a raster data set developed using the precipitation-zone method, which uses elevation-based regression equations to estimate mean annual precipitation for defined precipitation zones (Lopes and Medina, 2007.) This data set is based on the 30-meter National Elevation Dataset. Reference Cited Lopes, T.J., and Medina, R.L., 2007, Precipitation Zones of West-Central Nevada: Journal of Nevada Water Resources Association, v. 4, no 2, p. 21. The intended uses of this data set include, but are not limited to, natural resource modeling, mapping, and visualization applications. Precipitation estimates change abruptly between zones, especially along high elevations of the zone boundary. This is different than other precipitation maps that show precipitation varies continuously across Nevada but, as data indicate, precipitation can abruptly change over short distances (Lopes and Medina, 2007.) The following table is the summary of the precipitation regression analysis (Lopes and Medina, 2007.) >Precipitation N Intercept Slope Adjusted MAE, MAE, >Zone inches/year/foot R squared inches/year percent >-------------------------------------------------------------------------------- >Carson 19 -9.2 0.00382 0.92 1.4 10 >Sierra Slope 36 -31.0 0.01010 0.89 3.9 17 >Truckee 21 -21.0 0.00670 0.95 2.0 12 >Walker 30 -2.3 0.00167 0.90 0.8 12 Reference Cited Lopes, T.J., and Medina, R.L., 2007, Precipitation Zones of West-Central Nevada: Journal of Nevada Water Resources Association, v. 4, no 2, p. 21. 1971 2000 the publication date of the source data Complete None planned -120.801940 -116.904360 41.695168 37.123672 none mean annual precipitation precipitation-zone method PZM ISO 19115 Topic Category climatologyMeteorologyAtmosphere inlandWaters none Nevada Great Basin United States none Acknowledgment of the U.S. Geological Survey and the Bureau of Reclamation would be appreciated in products derived from these data. Although this Federal Geographic Data Committee (FGDC) compliant metadata file is intended to document the data set in nonproprietary form, this metadata file may include some ArcGIS-specific terminology. These data are not intended to be used as a survey product and are for reference only. U.S. Geological Survey Nevada Water Science Center Public Information Officer mailing and physical address

2730 N. Deer Run Road

Carson City NV 89701 USA (775)887-7600 (775)887-7629 Compilation of this data set and the associated metadata was done in cooperation with the Bureau of Reclamation. Technical review of this database was done by Susan G. Buto and J. LaRue Smith of the U.S. Geological Survey. Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.4.1420 The attribute value is the mean annual precipitation derived from the regression equations. When the data set was grouped into a data range, the grouped data value was compared to the original data value at selected areas. Throughout the processing, tests of valid values were determined. All areas were completely described. No inconsistencies were determined. Complete for west-central Nevada All attempts were made to compare the raster data representation to the original source data by visual inspection of selected areas. The horizontal accuracy of the data is based on the National Elevation Dataset (NED) which is variable. The primary source data of the NED were the U.S. Geological Survey 7.5-minute (30-meter or 10-meter resolution) Digital Elevation Models (DEMs) (U.S. Geological Survey, 2007b). 7.5-minute DEM accuracy is "similar to manual interpretations of information as printed at map scales not larger than 1:24,000-scale" (U.S. Geological Survey, 2007a). National Map Accuracy Standards (NMAS) established for the United States in 1947 (U.S. Geological Survey, 1988) state that no more than 10 percent of features shall be more than 1/50th of an inch from their intended location on maps of scale smaller than 1:20,000. National Standards for Spatial Data Accuracy (NSSDA) published by the Federal Geographic Data Committee (FGDC) in 1998 relate the National Map Accuracy Standards (NMAS) to the digital geospatial data standard by multiplying the NMAS accuracy by a factor of 1.1406 resulting in expected error in the geospatial data at 1:24,000-scale as 14 meters. References Cited FGDC, Subcommittee for Base Cartographic data, 1998, Geospatial Positioning Accuracy Standards, Part 3: National Standard for Spatial Data Accuracy, FGDC-STD-007.3-1998, last accessed 03/29/2007 at URL http://www.fgdc.gov/standards/projects/FGDC-standards-projects/accuracy/part3/chapter3 U.S. Geological Survey, 1988, National mapping program technical instructions - Part 2: Specifications, Standards for Digital Line Graphs: U.S. Geological Survey, 56 p. U.S. Geological Survey, 2007a, Digital Elevation Model Guide: DEM Accuracy, last accessed 09/10/2007 at URL http://eros.usgs.gov/guides/dem.html#accuracy. U.S. Geological Survey, 2007b, National Elevation Dataset: Accuracy of the National Elevation Dataset, last accessed 09/07/2007 at URL http://ned.usgs.gov/Ned/accuracy.asp. 14 meters The horizontal positional error is deductively estimated at 14 meters. Vertical accuracy of the source data can vary. 7 to 15 meters average vertical accuracy of the NED (accessed August 21, 2007 at URL http://ned.usgs.gov/Ned/faq.asp#vertical) U.S. Geological Survey Unknown raster digital data http://gisdata.usgs.gov/NED 24000 online unknown publication date of source DEM NED spatial and attribute information Rose L. Medina Thomas J. Lopes 2007 vector digital data Reston, VA U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?jnwra_v4n2_pzb online 1971 2000 the publication date of the source data PZB spatial and attribute information Thomas J. Lopes Rose L. Medina 2007 document Journal of Nevada Water Resources Association Volume 4, Number 2 Reno, NV Nevada Water Resources Association http://www.nvwra.org/journal/vol4no2.asp document 1971 2000 the publication date of the source regEQ attribute information The NED was acquired, merged, and projected to NAD 1983 UTM Zone 11N. Details are unknown. NED Unknown NED83 NED83 was masked to the extent of precipitation-zone boundaries (PZB). The extent was set to PZB. The snap raster and the cell size were set to NED83. ArcGIS 9.2: ArcToolbox>Spatial Analyst Tools>Extraction>Extract by Mask NED83 PZB 200708 elev30 Elev30 was converted to integer format. The extent, snap raster and cell size were set to elev30. ArcToolbox>Spatial Analyst Tools>Map Algebra>Single Output Map Algebra: "elev30 + 0.5" elev30_r # ArcToolbox>Spatial Analyst Tools>Math>Int elev30 200708 elev30i Elev30i values were rounded to the nearest ten feet in Microsoft Excel using the add-in function "USGSRound" to apply U.S. Geological Survey rounding rules. 1. Exported attribute table: ArcCatalog>Preview Table>Options button>Export... 2. Imported into Microsoft Excel: Data>Import External Data>Import Data 3. Converted meters to feet using a factor of 3.280839895. 4. Feet rounded to nearest ten feet using the USGSRound add-in function and saved to the remap text file, remap10.txt. Where remap10.txt: 1013 : 3320 1014 : 3330 1015 : 3330 etc. elev30i 200708 remap10.txt Elev30i was reclassified from meters to feet (rounded to the nearest ten feet) using remap10.txt. The extent, snap raster and cell size were set to elev30i. ArcGIS 9.2: ArcToolbox>Spatial Analyst Tools>Reclass>Reclass by ASCII File elev30i remap10.txt 200708 elev10ft Each precipitation zone in PZB was made into an individual feature class. The PZB data set was used as the input and split features and ZoneName was the split field. ArcGIS 9.2: ArcToolbox>Analysis Tools>Extract>Split PZB 200708 CarsonPZ SierraSlopePZ TruckeePZ WalkerPZ Elev10ft was masked to each precipitation-zone feature class. The extent was set to each precipitation-zone feature class. The snap raster and the cell size were set to elev10ft. ArcGIS 9.2: ArcToolbox>Spatial Analyst Tools>Extraction>Extract by Mask elev10ft CarsonPZ SierraSlopePZ TruckeePZ WalkerPZ 200708 elev10ftCPZ elev10ftSPZ elev10ftTPZ elev10ftWPZ Elevation values (elev10ft*PZ) were used with the corresponding regression equation (regEQ) to determine an estimated precipitation value. 1. Exported each table: ArcCatalog>Preview Table>Options button>Export... 2. Regression equation applied 3. A remap file containing elevation and corresponding precipitation estimate (inchX10) was produced. elev10ftCPZ elev10ftSPZ elev10ftTPZ elev10ftWPZ regEQ 200708 remap_CPZ.txt remap_SPZ.txt remap_TPZ.txt remap_WPZ.txt Each elev10ft*PZ was reclassified from elevation values to precipitation estimate values (inch X 10) using remap_*PZ.txt. Where remap_*PZ.txt: 3380 : 37 3390 : 37 3400 : 38 etc. The extent, snap raster and cell size were set to elev10ft*PZ. ArcGIS 9.2: ArcToolbox>Spatial Analyst Tools>Reclass>Reclass by ASCII File elev10ftCPZ elev10ftSPZ elev10ftTPZ elev10ftWPZ remap_CPZ.txt remap_SPZ.txt remap_TPZ.txt remap_WPZ.txt 200708 CPZinX10 SPZinX10 TPZinX10 WPZinX10 The four precipitation estimate rasters (*PZinX10) were merged into one. The extent, snap raster and cell size were set to elev10ft. ArcGIS 9.2: ArcMap>Spatial Analyst Toolbar>Raster Calculator>PZinX10 = merge([CPZinX10],[SPZinX10],[TPZinX10,[WPZinX10]) CPZinX10 SPZinX10 TPZinX10 WPZinX10 200708 PZinX10 The merged precipitation estimate raster was reclassified from inch X 10 to the nearest inch using remap_1in.txt. Where remap_1in.txt: 24 34 : 3 34 44 : 4 44 54 : 5 etc. The extent, snap raster and cell size were set to PZinX10. ArcGIS 9.2: ArcToolbox>Spatial Analyst Tools>Reclass>Reclass by ASCII File PZinX10 remap_1in.txt 200708 PZ1in Metadata structured and validated using the U.S. Geological Survey Geospatial Metadata Validation Service, accessed August 28, 2007 at URL http://geo-nsdi.er.usgs.gov/validation/. 200708 Raster Pixel 16713 10822 1 Universal Transverse Mercator 11 0.999600 -117.000000 0.000000 500000.000000 0.000000 row and column 30.000000 30.000000 meters North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 PZM1in raster data ESRI VALUE Mean annual precipitation estimate user-defined 3 79 inch COUNT Number of 30 meter square cells with VALUE ESRI Integer automatically generated with raster development U.S. Geological Survey Ask USGS -- Water Webserver Team mailing address

445 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://water.usgs.gov/user_feedback_form.html Although these data have 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 these data, software, or related materials. The use of firm, trade, or brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. The names mentioned in this document may be trademarks or registered trademarks of their respective trademark owners. File Geodatabase Spatial and attribute information WinZip 9.41 http://water.usgs.gov/GIS/dsdl/jnwra_v4n2_pz.gdb.zip ASCII Spatial and attribute information WinZip 10.8 http://water.usgs.gov/GIS/dsdl/jnwra_v4n2_pzm1in.asc.zip None. This data set is provided by USGS as a public service. 20071030 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing address

445 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+jnwra_v4n2_pzm1in FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998