Becker, Carol J. Runkle, Donna Rea, Alan 1997 1.0 map Open-File Report 96-449 Reston, VA U.S. Geological Survey https://water.usgs.gov/lookup/getspatial?ofr96-449_cond This data set consists of digitized polygons of constant hydraulic conductivity values for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately 193,000 acres and supplies ground water for irrigation, domestic, and industrial purposes in Beckham, Custer, Roger Mills, and Washita Counties along the divide between the Washita and Red River basins. The Elk City aquifer consists of the Elk City Sandstone and overlying terrace deposits, made up of clay, silt, sand and gravel, and dune sands in the eastern part and sand and gravel of the Ogallala Formation (or High Plains aquifer) in the western part of the aquifer. The Elk City aquifer is unconfined and composed of very friable sandstone, lightly cemented with clay, calcite, gypsum, or iron oxide. Most of the grains are fine-sized quartz but the grain size ranges from clay to cobble in the aquifer. The Doxey Shale underlies the Elk City aquifer and acts as a confining unit, restricting the downward movement of ground water. Values of hydraulic conductivity used as input to the ground-water flow model and in this data set are: 50 gallons per day per foot squared or 6.7 feet per day for the Elk City Sandstone; 500 gallons per day per foot squared or 66.8 feet per day for the Quaternary terrace deposits and dune sand; and 750 gallons per day per foot squared or 100.3 feet day for the Ogallala Formation. The hydraulic conductivity polygons from a ground-water modeling thesis were transferred to a photocopy of a paper map and digitized. The source map was published at a scale of 1:63,360. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data. 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 that could be used in ground-water vulnerability analysis. Introduction -- This data set consists of digitized polygons of constant hydraulic conductivity values for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately 193,000 acres and supplies ground water for irrigation, domestic, and industrial purposes in Beckham, Custer, Roger Mills, and Washita Counties along the divide between the Washita and Red River basins (Lyons, 1981). The Elk City aquifer consists of the Elk City Sandstone and overlying terrace deposits, made up of clay, silt, sand and gravel, and dune sands in the eastern part and sand and gravel of the Ogallala Formation (or High Plains aquifer) in the western part of the aquifer (Lyons, 1981). The Elk City aquifer is unconfined and composed of very friable sandstone, lightly cemented with clay, calcite, gypsum, or iron oxide. Most of the grains are fine-sized quartz but the grain size ranges from clay to cobble in the aquifer (Lyons, 1981). The Doxey Shale underlies the Elk City aquifer and acts as a confining unit, restricting the downward movement of ground water. The terms permeability and permeability coefficient are used by Lyons (1981) when referring to hydraulic conductivity. Hydraulic conductivity is a more accepted term and is used in this report. Values of hydraulic conductivity used by Lyons (1981) as input to the ground-water flow model and included in this data set for the Elk City aquifer are: 50 gallons per day per foot squared or 6.7 feet per day for the Elk City Sandstone; 500 gallons per day per foot squared or 66.8 feet per day for the Quaternary terrace deposits and dune sand; and 750 gallons per day per foot squared or 100.3 feet day for the Ogallala Formation. For this report the values of hydraulic conductivity are assigned to the polygons shown by Lyons (1981, figs. 11 and 12). Lyons used a quarter-mile grid and the weighted average hydraulic conductivity where the Elk City Sandstone is overlain by Quaternary deposits or by the Ogallala Formation. Kent, Lyons, and Witz (1982) used the same hydraulic conductivity polygons, but used permeabilities of 55 gallons per day per foot squared or 7.4 feet per day for the western part of the aquifer and 62 gallons per day per foot squared or 8.3 feet per day for the eastern part of the aquifer. Digital Line Graph (DLG) format requires numbers to be stored as integers. Therefore, the hydraulic conductivity in feet per day was multiplied by 10 and stored in the digital data sets as tenths of a foot per day. For example 66.8 feet per day was multiplied by 10 and stored in the digital data sets as 668 tenths of a foot per day. The hydraulic conductivity polygons from the ground-water modeling thesis, "A ground-water management model for the Elk City aquifer in Washita, Beckham, Custer and Roger Mills Counties, Oklahoma," by Lyons (1981, figs 11 and 12) were transferred to a photocopy of a paper map (plate 2) and digitized. The source map was published at a scale of 1:63,360. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. The hydraulic conductivity and recharge are closely interrelated. As long as these two model inputs are in balance the model has a small mean residual; it represents the natural system numerically. If the hydraulic conductivity is accurately known, the model can be used to accurately determine recharge. Likewise, if the hydraulic conductivity is poorly known, then the recharge will be poorly determined. Therefore, values of hydraulic conductivity used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data. In most aquifers, hydraulic conductivity measurements made in wells or in cores will range over several orders of magnitude, even over short horizontal and vertical distances. Hydraulic conductivity values derived from ground-water flow models represent areal generalizations and do not reflect the large local variance in well or core measurements. 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 -- Environmental Systems Research Institute, Inc. (ESRI), 1995, ARC/INFO Command Reference, ARC/INFO On-line manuals: Redlands, CA. Kent, D.C., Lyons T.D., and Witz, F.E., 1982, Evaluation of aquifer performance and water supply capabilities of the Elk City aquifer in Washita, Beckham, Custer, and Roger Mills Counties, Oklahoma: Stillwater, OK, Department of Geology, Oklahoma State University report, 96 p., 29 figs. (Final report to the Oklahoma Water Resources Board) Lyons, T.D., 1981, A ground-water management model for the Elk City aquifer in Washita, Beckham, Custer and Roger Mills Counties, Oklahoma: Stillwater, OK, Oklahoma State University, master's thesis, 88 p., 2 pls., 43 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. 1981 publication date Complete None planned -99.6799 -99.0740 35.5458 35.2192 USGS Thesaurus ground-water vulnerability groundwater vulnerability aquifers ground water groundwater Elk City aquifer Elk City Sandstone aquifer Elk City Sandstone hydraulic conductivity permeability permeability coefficent coefficent of permeability inlandWaters ISO 19115 Topic Category geoscientificInformation inlandWaters environment USGS Metadata Identifier USGS:588db009-f363-4165-81d7-2c780889b737 Geographic Names Information System western Oklahoma None. This data set was digitized from a photocopy of a map published at a scale of 1:63,360, and represents the hydraulic conductivity polygons as reported by Lyons (1981). Hydraulic conductivity polygons represented at this scale are indicative of broad, regional trends and should not be interpreted as site-specific. The hydraulic conductivity polygons were drawn onto and digitized from a plate size, 29 inches by 39 inches, paper material, with a maximum registration root-mean-squared error (RMSE) of 0.016 map inches (0.041 map centimeters) and 82 feet (25 meters) ground distance. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. The hydraulic conductivity and recharge are closely interrelated. As long as these two model inputs are in balance the model has a small mean residual; it represents the natural system numerically. If the hydraulic conductivity is accurately known, the model can be used to accurately determine recharge. Likewise, if the hydraulic conductivity is poorly known, then the recharge will be poorly determined. Therefore, values of hydraulic conductivity used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data. In most aquifers, hydraulic conductivity measurements made in wells or in cores will range over several orders of magnitude, even over short horizontal and vertical distances. Hydraulic conductivity values derived from ground-water flow models represent areal generalizations and do not reflect the large local variance in well or core measurements. 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 https://water.usgs.gov/GIS/browse/ofr96-449.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) Polygon and chain-node topology present. This data set includes all the values of hydraulic conductivity published on pages 27 and 28 and the areas of specified hydraulic conductivity published on figures 11 and 12 by Lyons (1981). None 16 meters Resolution as reported None. The hydraulic conductivity polygons shown by Lyons (1981, figs. 11 and 12) were transferred to a photocopy of a paper map (plate 2). A tic data set was created using 1:250,000-scale U.S. Geological Survey quadrangle maps. Five tics were registered on the source map and the hydraulic conductivity polygons were digitized in one session with a maximum registration root-mean-square-error (RMSE) of of 0.016 map inches (0.041 map centimeters) and 85.3 feet (26 meters) ground distance. 19960314 The data set was edited and the ARC/INFO CLEAN command (ESRI, 1995) was used with a dangle length of 32.8 feet (10 meters) ground distance and a fuzzy tolerance of 6.6 feet (2 meters) ground distance. 19960315 Polygons were attributed for K and lines were attributed for LSOURCE. The data set was plotted and compared to source map for accuracy. 19960329 The data set was documented. 19960424 The data set was edited and the ARC/INFO CLEAN command (ESRI, 1995) was used with a dangle length of 49.2 feet (15 meters) ground distance and a fuzzy tolerance of 49.2 feet (15 meters) ground distance. 19960823 Vector Point 5 String 10 GT-polygon composed of chains 6 Albers Conical Equal Area 45.5 45.5 -96 23 0.0 0.0 coordinate pair 16 meters 16 meters METERS North American Datum of 1983 Geodetic Reference System 80 6378137 298.257 COND.PAT Polygon attribute table ARC/INFO - Polygon attribute table ARC/INFO - n/a n/a AREA Area of polygon in square coverage units Computed Positive real numbers n/a n/a PERIMETER Perimeter of polygon in coverage units Computed Positive real numbers n/a n/a COND# Internal feature number Computed Sequential unique positive integer n/a n/a COND-ID User-assigned feature number User-defined Integer n/a n/a K Hydraulic conductivity in tenths of a foot per day Lyons (1981) 67, 668, 1003 n/a n/a MINOR1 Blank item for DLG Calculated 0 n/a n/a MAJOR1 Hydraulic conductivity in tenths of a foot per day Lyons (1981) 67, 668, 1003 n/a n/a COND.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 COND# Internal feature number Computed Sequential unique positive integer n/a n/a COND-ID User-assigned feature number User-defined Integer n/a n/a LSOURCE Source of line Lyons (1981) 1 n/a n/a MINOR1 Blank item for DLG Calculated 0 n/a n/a MAJOR1 Source of line Lyons (1981) 1 n/a n/a Each polygon in this data set has an associated attribute, K, containing values of hydraulic conductivity (Lyons, 1981) expressed in tenths of a foot per day. For example, the hydraulic conductivity of 66.8 feet per day is stored as a K value of 668. K is stored in the first major code (MAJOR1) for polygons, and 0 is stored in the first minor code (MINOR1) in the Digital Line Graph (DLG) version of this data set. Each line in this digital data set has an associated attribute, LSOURCE, that contains a code to indicate the source of the line. An LSOURCE code of 1 indicates the line was digitized from Lyons (1981). LSOURCE is stored in the first major code (MAJOR1) for lines, and 0 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 Michael Ierardi IT Specialist mailing

445 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) mierardi@usgs.gov 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 https://water.usgs.gov/GIS/dsdl/ofr96-449_cond.e00.gz Other DLG file format zipped 1 https://water.usgs.gov/GIS/dsdl/ofr96-449_cond.dlg.gz None. This dataset is provided by USGS as a public service. 20201117 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing

445 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) mierardi@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998