Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

This data set consists of digitized polygons of constant
recharge 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.

The recharge polygon boundaries were transfered from a figure in
the ground-water model thesis for the Elk City aquifer to a
photocopy of a paper map and digitized. The source map was
published at a scale of 1:63,360.

The Elk City aquifer was divided into three subareas based on
soil type and topography and assigned the recharge rates 2.00,
3.92, and 4.00 inches per year in a ground-water model thesis.
These subareas and recharge rates are used in this data set.

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 recharge 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.