Alan Rea Robert L. Tortortelli 1997 Unknown 1.0 map Open-File Report 97-574 Oklahoma City U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?ofr97-574_ok_maprecip This digital-map data set consists of a grid of mean annual precipitation, in inches, based on the period 1961-90, for Oklahoma. The data set was derived from the PRISM (Parameter-elevation Regressions on Independent Slopes Model) mean annual precipitation grid for the United States, developed by Daly, Neilson, and Phillips (1994, "A statistical-topographic model for mapping climatological precipitation over mountainous terrain:" Journal of Applied Meteorology, v. 33, no. 2, p. 140-158). The precipitation grid was used to develop peak-flow regression equations by Tortorelli, (1997, "Techniques for estimating peak-streamflow frequency for unregulated streams and streams regulated by small floodwater retarding structures in Oklahoma," U.S. Geological Survey Water-Resources Investigations Report 97-4202.) This data set was used for regression analyses and estimation of peak-streamflow frequency in Oklahoma by Tortorelli (1997). This digital-map data set consists of a grid of mean annual precipitation, in inches, based on the period 1961-90, for Oklahoma. The data set was derived from the PRISM (Parameter-elevation Regressions on Independent Slopes Model) mean annual precipitation grid for the United States, developed by Daly, Neilson, and Phillips (1994). The precipitation grid was used to develop peak-flow regression equations by Tortorelli (1997). Reviews_Applied_to_Data-- This electronic report was subjected to the same review standard that applies to all U.S. Geological Survey reports. Reviewers were asked to check the topological consistency, tolerances, attribute frequencies and statistics, projection, and geographic extent. Reviewers were given digital data sets and paper plots for checking against the source maps. The reviewers were asked to check the metadata and accompanying files for completeness and accuracy. Related_Spatial_and_Tabular_Data_Sets-- This data set is one of two digital map data sets being published for this report. The two data sets are: skewgrid - generalized peak streamflow skew coefficients maprecip - mean annual precipitation These data sets were used in regression analyses by Tortorelli (1997), and are being published so the data sets may be used to apply the regression equations to estimate peak streamflow frequencies. Other_References_Cited-- Daly, C., R.P. Neilson, and D.L. Phillips, 1994, A statistical- topographic model for mapping climatological precipitation over mountainous terrain: Journal of Applied Meteorology, v. 33, no. 2, p. 140-158. Environmental Systems Research Institute, Inc. (ESRI), 1995, ARC/INFO Command Reference: Redlands, CA. Tortorelli, R.L., 1997, Techniques for estimating peak-streamflow frequency for unregulated streams and streams regulated by small floodwater retarding structures in Oklahoma: U.S. Geological Survey Water-Resources Investigations Report 97-4202, 39 p. Notes-- 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 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. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, this metadata file was developed using the DOCUMENT program of ARC/INFO. Therefore, this metadata file may include some ARC/INFO-specific terminology. minimum: 10.39367961883 maximum: 68.58254241943 Data_Set_Credit-- The U.S. Geological Survey compiled this data set and the associated metadata in cooperation with the Oklahoma Department of Transportation. 1961 1990 publication date Complete None planned -103.6117 -93.5745 38.2657 33.1905 None precipitation mean annual precipitation climatological data Oklahoma inlandWaters None The cell size of this data set is 4.7 kilometers. The data were extracted from a nationwide grid of estimated mean annual precipitation. The data are interpolated from observed precipitation, and should not be considered site specific. Alan Rea U.S. Geological Survey Hydrologist mailing address

202 NW 66th St., Bldg. 7

Oklahoma City Oklahoma 73116 United States of America 1-888-275-8747 (405)843-7712 ahrea@usgs.gov Please use email. Operating System-- UNIX, ARC/INFO Version 7.0.3,,(Mon Mar 13 22:21:55 PST 1995) Not available This data set includes Oklahoma and a margin in the surrounding states. The nationwide grid of mean annual precipitation was downloaded from the PRISM Internet site (http://www.ocs.orst.edu/prism/prism_new.html). The grid was imported into ARC/INFO using the ASCIIGRID command (ESRI, 1995). The grid was projected from degrees of latitude and longitude to Albers Equal Area map projection, using standard parallels selected for Oklahoma, and the North American Datum of 1983 (NAD83) for the horizontal datum. The cell size in latitude and longitude was 2.5 minutes, and became 4.7 kilometers (km) in Albers Equal Area. The values were converted from millimeters to inches. An area including Oklahoma and the watersheds for all gages used by Tortorelli (1997) was extracted. Processing was done by Alan Rea. 19970430 Raster Grid Cell 118 193 Albers Conical Equal Area 34 36.5 -98 33 0.0 0.0 coordinate pair 4719.455 4719.455 meters North American Datum of 1983 Semi-major_Axis UNKNOWN The values stored in the grid cells equal the estimated mean annual precipitation for the period 1961-1990, expressed in inches. See overview. U.S. Geological Survey Ask USGS - Water Webserver Team mailing

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+ofr97-574_ok_maprecip 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. Grid Mean Annual Precipitation ASCII grid, in inches 1 http://water.usgs.gov/GIS/dsdl/OK/maprecip.asc Other Map-projection parameters for the mean annual precipitation data set 1 http://water.usgs.gov/GIS/dsdl/OK/maprecip.prj None. This dataset is provided by USGS as a public service. 20041108 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing

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+ofr97-574_ok_maprecip FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998