GEOGRAPHIC INFORMATION SYSTEM DATA BASE

Whether studying ground water or surface water, or water quantity or quality, one must consider many factors, such as geology, soils, topography, land use, water use, demographics, and political subdivisions. Broad-based support for water-resources planning requires the dissemination of information on issues, alternatives, and the consequences of policy decisions. In general, this information must be gathered from a variety of sources and summarized in a manner that clearly displays the information. As part of its research and public service activities, the Kentucky Geological Survey is assembling a spatial data base for water-resources planning and management.

Spatial distribution of the above factors at a Statewide and basin scale is being entered into the Arc/Info geographic information system at the Survey on a project-by-project basis. These data are available to outside agencies and the public, and are being used to support water-, coal-, and petroleum-resource studies. KGS is continuing the expansion of the spatial data base to include such data as the demographics of water supply and use, sewage and waste disposal, mapping of public and private water-supply service areas, and other data related to water-resource management.

During the past year, GIS has been employed to map ground-water parameters on a Statewide scale. GIS coverages have been completed for depth to water, ground-water surface elevation, and depth to bedrock for the entire State. Coverages for some counties have been completed for nitrate-nitrogen, and we are now able to map other water-quality parameters, including pesticides, major cations and anions, and trace elements.

A menu-driven interface has been designed to allow the user to define the number of counties to be mapped, the contour interval, the parameter to be contoured, and the map scale. Work is continuing on the development of the interface in order to broaden its application to a wider variety of data and map types.

The majority of the data used to generate these GIS coverages was provided by water-well drillers at the time each well was completed. The wells from which these data were taken were completed between 1985 and 1993. Total depths of the wells range from 10 feet to 800 feet. Over 200,000 unregistered private water wells are estimated to exist in Kentucky; therefore, only about 10 percent of all the wells are represented in our data base.

These GIS coverages are currently being developed into publications that should prove useful to the general public, water-well drillers, environmental geologists and engineers, land-use planners, and other research organizations.