Becker, Carol J. Runkle, Donna Rea, Alan 1997 1.0 map Open-File Report 96-452 Reston, VA U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?ofr96-452_wlelev This data set consists of digital water-level elevation contours for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace and alluvial aquifer is an unconfined aquifer that extends over an area of approximately 285 square miles and is used for irrigation and domestic purposes. The aquifer encompasses the unconsolidated terrace deposits and river alluvium associated with the North Fork of the Red River and the Red River in the western half of Tillman County. These sediments consist of discontinuous layers of clay, sandy clay, sand, and gravel. Water-level elevation contours for ground-water levels measured in 1969 were digitized from a paper map in a thesis in which the ground-water flow was modeled in the Tillman terrace and alluvial aquifer. The map was published at a scale of 1:249,695. Water-level elevations ranged from about 1,360 feet above sea level in the eastern part of the aquifer to 1,120 feet above sea level in the southern part of the aquifer. This data set was created for a project to develop data sets to support ground-water vulnerability analysis. The objective was to create and document a digital geospatial data set from a published report or map, or existing digital geospatial data sets that could be used in ground-water vulnerability analysis. Introduction -- This data set consists of digital water-level elevation contours for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace and alluvial aquifer is an unconfined aquifer that extends over an area of approximately 285 square miles and is used for irrigation and domestic purposes. The ground-water flow model of the aquifer by Al-Sumait (1978) encompasses the unconsolidated terrace deposits and river alluvium associated with the North Fork of the Red River and the Red River in the western half of Tillman County. These sediments consist of discontinuous layers of clay, sandy clay, sand, and gravel (Al-Sumait, 1978). In this report, elevation refers to distance above sea level and sea level refers to the National Gedodetic Vertical Datum of 1929 (NGVD29)--a geodetic datum derived from a general adjustment of the first-order level nets of both the United States and Canada, formerly called Sea Level Datum of 1929. A map in Al-Sumait (1978) shows the elevation of ground-water levels measured in the aquifer in 1969 ranged from about 1,360 feet above sea level in the eastern part of the aquifer to 1,120 feet above sea level in the southern part of the aquifer. The thesis by Al-Sumait (1978) also shows the elevation of the ground-water levels in the aquifer in 1974 (p. 51, fig. 15), however, these data were used for comparative purposes and were not used as input to the ground-water flow model. Water-level elevation contours were digitized from a paper map in the thesis, "A computer ground-water model for the Tillman alluvium in Tillman County, Oklahoma," by Al-Sumait (1978, p. 17, fig. 4, 1969 water-head elevation), published at a scale of 1:249,695. 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 to verify the linework and attributes. The reviewers checked the metadata and a_readme.1st files for completeness and accuracy. Related Spatial and Tabular Data Sets -- This data set is one of four digital map data sets being published together for this aquifer. The four data sets are: > aqbound - aquifer boundaries > cond - hydraulic conductivity > recharg - aquifer recharge > wlelev - water-level elevation contours Digital map data sets of the Oklahoma surficial geology digitized from 1:250,000-scale maps (or 1:125,000-scale maps for the three Oklahoma panhandle counties) are published separately. Other References Cited -- Al-Sumait, A.J., 1978, A computer ground-water model for the Tillman alluvium in Tillman County, Oklahoma: Stillwater, OK, Oklahoma State University, master's thesis, 152 p., 48 figs. 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. 1969 ground conditions Complete None planned -99.2236 -98.9853 34.6295 34.2017 none ground-water vulnerability groundwater vulnerability aquifers ground water groundwater ground-water levels groundwater levels water levels ground-water level elevation groundwater level elevation ground-water level elevation contours groundwater level elevation contours water-level elevation contours water level elevation contours water-level contours water level contours water-level elevation water level elevation Tillman terrace and alluvial aquifer Tillman terrace aquifer Tillman aquifer Tillman alluvial aquifer Tillman alluvial and terrace aquifer terrace deposit alluvial deposit terrace and alluvial aquifer alluvial and terrace aquifer terrace aquifer alluvial aquifer inlandWaters none southwestern Oklahoma None. This data set was digitized from a map published at a scale of was of 1:249,695. The map represents the elevations of water levels in the aquifer in 1969 (Al-Sumait, 1978). Water-level elevation contours represented at this scale are indicative of broad, regional trends and should not be interpreted as site specific. The water-level elevation contours were digitized from paper map (8 inches by 11 inches) with a maximum registration root-mean-squared-error (RMSE) of 0.007 map inches (0.018 map centimeters) and 456 feet (139 meters) ground distance. Carol J. Becker 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 cjbecker@usgs.gov none http://water.usgs.gov/lookup/get?OFR96-452/browse.gif A browse image of the four aquifer data sets. GIF Compilation of this data set and the associated metadata was funded under a cooperative Joint Funding Agreement between the U.S. Geological Survey and the State of Oklahoma, Office of the Secretary of Environment. Public UNCLASSIFIED None Operating System-- UNIX, ARC/INFO Version 7.0.3,(Mon Mar 13 22:21:55 PST 1995) Chain-node topology present. This data set includes all the 1969 water-level elevation contours published on figure 4, page 17 by Al-Sumait (1978). None 10 meters Resolution as reported None. A tic data set was created using 1:250,000-scale U.S. Geological Survey quadrangle maps. The hydraulic conductivity polygon representing the aquifer was digitized in one session with a maximum registration root-mean-squared-error (RMSE) of 0.007 map inches (0.018 map centimeters) and 456 feet (139 meters) ground distance. 19960319 Digitized contours were edited and the contours were attributed for LTYPE and ELEV. The data set was plotted and compared to the source map for accuracy. 19960426 Vector Point String 26 GT-polygon composed of chains Albers Conical Equal Area 29.5 45.5 -96 23 0.0 0.0 coordinate pair 10 meters 10 meters METERS North American Datum of 1983 Geodetic Reference System 80 6378137 298.257 WLELEV.AAT Arc attribute table ARC/INFO - Arc attribute table ARC/INFO - n/a n/a FNODE# Internal number of from-node Computed Sequential unique positive integer n/a n/a TNODE# Internal number of to-node Computed Sequential unique positive integer n/a n/a LPOLY# Internal number of poly to left of arc Computed Sequential unique positive integer n/a n/a RPOLY# Internal number of poly to right of arc Computed Sequential unique positive integer n/a n/a LENGTH Length of arc in coverage units Computed Positive real numbers n/a n/a WLELEV# Internal feature number Computed Sequential unique positive integer n/a n/a WLELEV-ID User-assigned feature number User-defined Integer n/a n/a ELEV Water-level contour elevation in feet above NGVD29 Al-Sumait (1978) 1,120 1,360 LTYPE Line type Al-Sumait (1978) 1 n/a n/a MAJOR1 Water-level contour elevation in feet above NGVD29 Al-Sumait (1978) 1,120 1,360 MINOR1 Line type Al-Sumait (1978) 1 n/a n/a Two attributes are associated with each line in this digital data set. The first attribute, ELEV, contains the elevation of the water-level contour, expressed in feet above the North American Vertical Datum of 1929 (NGVD29). The second attribute, LTYPE, contains a code of 1 indicating a solid line is shown on the published map. ELEV is stored in the first major code (MAJOR1) for lines, and LTYPE is stored in the first minor code (MINOR1) in the Digital Line Graph (DLG) version of this data set. See overview. U.S. Geological Survey Ask USGS - Water Webserver Team mailing

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Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ofr96-452_wlelev 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. Export Full coverage zipped 1 http://water.usgs.gov/GIS/dsdl/ofr96-452_wlelev.e00.gz Other DLG file format zipped 1 http://water.usgs.gov/GIS/dsdl/ofr96-452_wlelev.dlg.gz None. This dataset is provided by USGS as a public service. 20041108 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing

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Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ofr96-452_wlelev FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998