DIGITAL DATA SETS THAT DESCRIBE AQUIFER CHARACTERISTICS OF THE CENTRAL OKLAHOMA AQUIFER IN CENTRAL OKLAHOMA

By Donna Runkle and Alan Rea with source data sets and supplemental information provided by Scott Christenson

U.S. Geological Survey Open-File Report 96-454

Prepared in cooperation with the
State of Oklahoma, Office of the Secretary of Environment

Oklahoma City, Oklahoma
1997

TABLE OF CONTENTS

INTRODUCTION

The data sets in this report include digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Central Oklahoma aquifer in central Oklahoma. This area encompasses all or part of Cleveland, Lincoln, Logan, Oklahoma, Payne, and Pottawatomie Counties. The Central Oklahoma aquifer includes the alluvial and terrace deposits along major streams, the Garber Sandstone and Wellington Formations, and the Chase, Council Grove, and Admire Groups described in the report, "Ground-water-quality assessment of the Central Oklahoma aquifer, Oklahoma: Geochemical and Geohydrologic Investigations," by Parkhurst, Christenson, and Breit (1996).

The Quaternary-age alluvial and terrace deposits consist of unconsolidated clay, silt, sand, and gravel. The Permian-age Garber Sandstone and Wellington Formations consist of sandstone with interbedded siltstone and mudstone. The Permian-age Chase, Council Grove, and Admire Groups consist of sandstone, shale, and thin limestone (Parkhurst, Christenson, and Breit, 1996).

The Central Oklahoma aquifer underlies about 3,000 square miles of central Oklahoma where the aquifer is used extensively for municipal, industrial, commercial, and domestic water supplies. Most of the usable ground water within the aquifer is from the Garber Sandstone and Wellington Formations. Substantial quantities of usable ground water also are present in the Chase, Council Grove, and Admire Groups, and in alluvial and terrace deposits associated with the major streams (Parkhurst, Christenson, and Breit, 1996).

The aquifer boundaries and ground-water level elevation contours were digitized and published at a scale of 1:250,000 in the report, "Hydrogeologic maps of the Central Oklahoma aquifer, Oklahoma," by Christenson, Morton, and Mesander (1992). The hydraulic conductivity and recharge data are published in the report, "Ground-water-quality assessment of the Central Oklahoma aquifer, Oklahoma: Geochemical and Geohydrologic Investigations," by Parkhurst, Christenson, and Breit (1996). The hydraulic conductivity values are on pages C68-C69, C82, and C83 of Parkhurst, Christenson, and Breit (1996). The recharge values are on pages C70-C74, C79, and C83 of Parkhurst, Christenson, and Breit (1996).

Compilation of the data sets 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.

PURPOSE

These data sets were created for a project to develop data sets to support ground-water vulnerability analysis. The objective was to create and document digital geospatial data sets from published reports or maps, or existing digital geospatial data sets that could be used in ground-water vulnerability analysis.

FILE FORMATS

The data sets provided in this report are available in nonproprietary and ARC/INFO export file formats. (See NOTES section.) Files, except those with ".GIF" or ".GZ" extensions, are ASCII format files.

The data sets stored in the generic, public-domain Digital Line Graph (DLG-3) Version 3, Optional format have file extensions of ".DLG". Designed for data interchange, the DLG-3 format allows the simple creation of a vector polygon or line data structure. The topological linkages are explicitly encoded for node, area, and line elements. The files are composed of 8-bit ASCII characters organized into fixed logical records of 80 bytes. A detailed description of the DLG-3 Optional format may be found in the data users guide 3, Digital Line Graphs from 1:2,000,000-scale maps (U.S. Geological Survey, 1990).

The ARC/INFO export files are ASCII files that utilize a proprietary format. The "NONE" compression option was used with the ARC/INFO EXPORT command. The ARC/INFO export files have file extensions of ".E00".

The data set files have ".GZ" extensions and were compressed for distribution. These files need to be uncompressed to access the digital data. The GUNZIP utility is an MS-DOS executable program that will uncompress the data files. To uncompress a file, type at the MS-DOS prompt:

GUNZIP -aN AQBOUND.GZ

This command will uncompress the file and restore its original name. For example: "AQBOUND.DLG" or "AQBOUND.E00".

A documentation file (known as metadata) is provided for each data set. The documentation files comply with the Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (Federal Geographic Data Committee, 1994). The FGDC-compliant metadata files contain detailed descriptions of the data sets, and include narrative sections that describe the procedures used to produce the data sets in digital form.

A graphic image also is provided in a Graphics Interchange Format (GIF) file. GIF files are easily displayed on a variety of computer systems that use readily available display software including Internet browser software. This image provides a simplified view of the data sets, and may be used for browsing purposes. The GIF file portrays significantly less spatial resolution and information content than the actual data sets.

No software is provided with these data sets. Users will need GIS software to use the data sets. The U.S. Geological Survey does not recommend or endorse any particular software package for use with these data sets. For some links to more information on GIS software and capabilities, see:  The GIS FAQ (Frequently Asked Questions), GIS Companies on the WWW, USGS GIS Information.

DATA ORGANIZATION

A_NOTICE.TXT

Liability disclaimer

BROWSE.GIF

Browse image of the data sets in Graphics Interchange Format (GIF)

AQBOUND

Complete documentation of the data sources and procedures used to create the aquifer boundary data set and links for retrieval of the data set.

COND

Complete documentation of the data sources and procedures used to create the hydraulic conductivity data set and links for retrieval of the data set.

RECHARG

Complete documentation of the data sources and procedures used to create the recharge data set and links for retrieval of the data set.

WLELEV

Complete documentation of the data sources and procedures used to create the ground-water level elevation contour data set and links for retrieval of the data set.

GEOMETRIC REGISTRATION

The Albers Equal Area map projection (Snyder, 1987) was chosen for the data sets. This projection is appropriate for maps of the conterminous United States because of the visual presentation and equal-area characteristics, which facilitates areal analysis. The projection is cast on the North American Datum of 1983. This projection slightly distorts shapes and distances (scale) in order to maintain equal-area properties. Scale is true along the standard parallels, which are to the north and south of Oklahoma. Scale distortion in Oklahoma reaches a maximum of slightly less than one percent at the northern border of the state. The following table provides map projection information.

Albers Equal Area projection parameters
[GRS1980, Geodetic Reference System 1980; NAD83, North American Datum 1983]

Projection parameters:
Spheroid	GRS1980
Datum	NAD83
First standard parallel	29 30 00 North
Second standard parallel	45 30 00 North
Central meridian	96 00 00 West
Latitude of projection origin	23 00 00 North
Coordinate system parameters:
False easting	0
False northing	0
Planimetric units of measure	meters

NOTES

Use of trade names is for descriptive purposes only, and does not imply endorsement by the U.S. Government.

ARC/INFO software was used in the development of the data sets. The data sets were processed using the ARC/INFO Revision 7.0.3 software package, running on a Data General AViiON workstation. Further processing was done using ARC/INFO Revisions 7.0.4 and 7.1.1 on a SUN Enterpise 4000 running Solaris Version 2.5.1. File names in this document are enclosed in quotation marks and type set in upper case.

REFERENCES CITED

Christenson, S.C., Morton, R.B., and Mesander, B.A., 1992, Hydrogeologic maps of the Central Oklahoma aquifer, Oklahoma: U.S. Geological Survey Hydrologic Investigations Atlas HA-724, 3 sheets, scale 1:250,000

Federal Geographic Data Committee, 1994, Content standards for digital geospatial metadata (June 8): Federal Geographic Data Committee, Washington, D.C., 78 p.