Digital hydraulic conductivity values of the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma

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 set that could be used in ground-water vulnerability analysis.

This data set consists of digital polygons of constant hydraulic conductivity
values for the alluvial and terrace deposits along the Cimarron River from
Freedom to Guthrie in northwestern Oklahoma. Ground water in 1,305 square miles
of Quaternary-age alluvial and terrace deposits along the the Cimarron River
from Freedom to Guthrie is an important source of water for irrigation,
industrial, municipal, stock, and domestic supplies. Alluvial and terrace
deposits are composed of interfingering lenses of clay, sandy clay, and
cross-bedded poorly sorted sand and gravel. The aquifer is composed of
hydraulically connected alluvial and terrace deposits that uncomfortably
overlie the Permian-age Formations.

The hydraulic-conductivity values for alluvial and terrace deposits used in
this data set were published in a steady-state ground-water flow modeling
report. The aquifer boundaries along geological contacts were extracted from
published digital geology data sets. Boundaries defining the geographic limits
of the aquifer were digitized from a mylar map, at a scale of 1:250,000. The
maps were published at a scale of 1:900,000. The hydraulic conductivity values
are 104.5 feet per day for the alluvial deposits and 47.5 feet per day for the
terrace deposits.

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.