Becker, Carol J.
Runkle, Donna
Rea, Alan
1997
Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma
1.0
map
OpenFile Report
96450
Reston, VA
U.S. Geological Survey
https://water.usgs.gov/lookup/getspatial?ofr96450_cond
This data set consists of digitized polygons of constant
hydraulic conductivity values for the Enid isolated terrace
aquifer in northwestern Oklahoma. The Enid isolated terrace
aquifer covers approximately 82 square miles and supplies water
for irrigation, domestic, municipal, and industrial use for the
City of Enid and western Garfield County. The Quaternaryage
Enid isolated terrace aquifer is composed of terrace deposits
that consist of discontinuous layers of clay, sandy clay, sand,
and gravel. The aquifer is unconfined and is bounded by the
underlying Permianage Hennessey Group on the east and the Cedar
Hills Sandstone Formation of the Permianage El Reno Group on
the west. Cedar Hills Sandstone Formation fills a channel
beneath the thickest section of the Enid isolated terrace
aquifer in the midwestern part of the aquifer.
The hydraulic conductivity polygons from a groundwater modeling
thesis and report were transferred to a map and digitized. The
map digitized was published at a scale of 1:62,500. Hydraulic
conductivities reported in the groundwater modeling thesis and
report for the Enid isolated terrace aquifer are 93.6 feet per
day and 134 feet per day.
Groundwater 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 groundwater 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 groundwater
vulnerability analysis.
Introduction 
This data set consists of digitized polygons of constant
hydraulic conductivity values for the Enid isolated terrace
aquifer in northwestern Oklahoma. The Enid isolated terrace
aquifer covers approximately 82 square miles and supplies water
for irrigation, domestic, municipal, and industrial use for the
City of Enid and western Garfield County (Beausoleil, 1981). The
Quaternaryage Enid isolated terrace aquifer is composed of
terrace deposits that consist of discontinuous layers of clay,
sandy clay, sand, and gravel. The aquifer is unconfined and is
bounded by the underlying Permianage Hennessey Group on the
east and the Cedar Hills Sandstone Formation of the Permianage
El Reno Group on the west. The Cedar Hills Sandstone Formation
fills a channel beneath the thickest section of the Enid
isolated terrace aquifer in the midwestern part of the aquifer
(Beausoleil, 1981).
The hydraulic conductivity polygons shown on figure 14 of the
groundwater modeling report, "A groundwater management model
for the Enid isolated terrace aquifer in Garfield County,
Oklahoma," by Beausoleil (1981) were transferred to a plate from
the report and digitized. The source map, plate 4, was published
at a scale of 1:62,500.
Beausoleil (1981) reports the aquifer was divided into two
regions based on the hydraulic conductivity of the sediments
underlying the aquifer. A channel fill of Cedar Hills Sandstone
Formation underlies the midwestern region of the aquifer. This
region was assigned a hydraulic conductivity value of 134 feet
per day. The remaining portion of the aquifer was assigned a
hydraulic conductivity of 93.6 feet per day. 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 set as tenths
of a foot per day. For example 93.6 feet per day was multiplied
by 10 and stored in the digital data set as 936 tenths of a
foot per day. The term permeability is used by Beausoleil (1981)
when referring to hydraulic conductivity. Hydraulic conductivity
is a more accepted term and is used in this report.
These polygons and associated values of hydraulic conductivity
also used by Kent, Beausoleil, and Witz (1982) in a groundwater
model of the Enid isolated terrace aquifer.
Groundwater 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 groundwater 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  waterlevel elevation contours
Digital map data sets of the Oklahoma surficial geology
digitized from 1:250,000scale maps (or 1:125,000scale maps for
the three Oklahoma panhandle counties) are published separately.
Other References Cited 
Beausoleil, Y.J., 1981, A groundwater management model for the Enid
isolated terrace aquifer in Garfield County, Oklahoma: Stillwater,
OK, Oklahoma State University, master's thesis, 66 p., 4 pls.,
25 figs.
Kent, D.C., Beausoleil, Y.J. and Witz, F.E., 1982, Evaluation of
aquifer performance and water supply capabilities of the Enid
isolated terrace aquifer in Garfield County, Oklahoma: Stillwater,
OK, Department of Geology, Oklahoma State University report,
58 p., 19 figs. (Final report to the Oklahoma Water Resource Board)
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
None planned
97.9764
97.7572
36.5099
36.3679
none
groundwater vulnerability
groundwater vulnerability
aquifers
ground water
groundwater
Enid isolated terrace aquifer
Enid terrace aquifer
Enid aquifer
terrace aquifer
terrace deposit
hydraulic conductivity
permeability
inlandWaters
none
northwestern Oklahoma
None.
This data set was digitized from a map published at a scale of
1:62,500 and represents the hydraulic conductivity polygons as
reported by Beausoleil (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 digitized from a photocopy
of a paper map (19.0 inches by 17.5 inches) with a maximum
registration rootmeansquarederror (RMSE) of 0.008 map inches
(0.020 map centimeters) and 42.7 feet (13 meters) ground
distance.
Groundwater 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 groundwater 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
18882758747
(405) 8437712
cjbecker@usgs.gov
none
http://water.usgs.gov/GIS/browse/ofr96450.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 chainnode topology present.
This data set includes all the areas of specified hydraulic
conductivity published on figure 14, page 36, by Beausoleil (1981).
None
29 meters
Resolution as reported
None.
A tic coverage was created using township and range corners
from 1:24,000 scale U.S. Geological Survey quadrangle maps.
19960830
The hydraulic conductivity polygons were digitized in one session
with a maximum registration rootmeansquared error (RMSE) of
0.008 map inches (0.020 map centimeters) and 42.7 feet (13 meters)
ground distance. The lines were attributed for LSOURCE
and the polygons were attributed for K.
19960904
Vector
Point
2
String
5
GTpolygon composed of chains
3
Albers Conical Equal Area
29.5
45.5
96
23
0.0
0.0
coordinate pair
29 meters
29 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
CONDID
Userassigned feature number
Userdefined
Integer
n/a
n/a
K
Hydraulic conductivity in tenths of a foot per day
Beausoleil (1981)
936, 1340
n/a
n/a
MAJOR1
Hydraulic conductivity in tenths of a foot per day
Beausoleil (1981)
936, 1340
n/a
n/a
MINOR1
Blank item for DLG
Calculated
0
n/a
n/a
COND.AAT
Arc attribute table
ARC/INFO

Arc attribute table
ARC/INFO

n/a
n/a
FNODE#
Internal number of fromnode
Computed
Sequential unique positive integer
n/a
n/a
TNODE#
Internal number of tonode
Computed
Sequential unique positive integer
n/a
n/a
LPOLY#
Internal number of polygon to left of arc
Computed
Sequential unique positive integer
n/a
n/a
RPOLY#
Internal number of polygon 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
CONDID
Userassigned feature number
Userdefined
Integer
n/a
n/a
LSOURCE
Source of line
Beausoleil (1981)
1
n/a
n/a
MAJOR1
Source of line
Beausoleil (1981)
1
n/a
n/a
MINOR1
Blank item for DLG
Calculated
0
n/a
n/a
Each polygon in this data set has an associated attribute, K,
containing values of hydraulic conductivity as reported by
Beausoleil (1981) expressed in tenths of a foot per day. The
hydraulic conductivity of 93.6 feet per day is stored as a K
value of 936 and 134 feet per day is stored as a K value of
1340. 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.
The LSOURCE code of 1 indicates the line was digitized from
Beausoleil (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
Ask USGS  Water Webserver Team
mailing
445 National Center
Reston
VA
20192
18882758747 (1888ASKUSGS)
http://answers.usgs.gov/cgibin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ofr96450_cond
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/ofr96450_cond.e00.gz
Other
DLG file format
zipped
1
https://water.usgs.gov/GIS/dsdl/ofr96450_cond.dlg.gz
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
18882758747 (1888ASKUSGS)
http://answers.usgs.gov/cgibin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ofr96450_cond
FGDC Content Standards for Digital Geospatial Metadata
FGDCSTD0011998