A Method for Identifying Karst Features in the Ozarks and Their Correlation to Ground-Water Quality Impacts

Science Center Objects

Short Title: Ozark Karst Study

Project Chiefs: Tim Kresse (USGS-Water), Phil Hays (USGS-Water), James Kaufmann (USGS-Geography), Mark Hudson (USGS-Geology), Esther Stroh (USGS-Biology)

Cooperator: U.S. Geological Survey

Project Time Frame: 2007 - 2011

Three major physiographic provinces in the Ozark Plateaus in Arkansas and Missouri include diverse topography and geomorphology, which greatly affects the hydrology of the area. Numerous studies within the Ozarks, combined with studies performed in karst environments worldwide, have documented the diverse hydrologic characteristics of karst aquifers and related susceptibility to surface-derived contamination.

Three major physiographic provinces in the Ozark Plateaus in Arkansas and Missouri include diverse topography and geomorphology, which greatly affects the hydrology of the area. Numerous studies within the Ozarks, combined with studies performed in karst environments worldwide, have documented the diverse hydrologic characteristics of karst aquifers and related susceptibility to surface-derived contamination.

Karst features (sinkholes, springs, caves, solution channels, losing streams, etc.) at the surface can lead to rapid transport of surface-derived contaminants with little to no attenuation. Existing information is available to help determine karst characteristics of hydrology (ground- and surface-water interaction); geology (orientation and density of joints and fractures, regolith thickness and type of bedrock); biology (location and health of particular plant and animal assemblages); or geography (a method has been developed of extracting sinkholes from LIDAR and high-resolution DEM data) in the Ozarks that can be directly measured in the field, remotely sensed, or derived from existing data or publications.

The purpose of the study is to identify the occurrence, nature, density, and distribution of karst features in the Ozarks to develop a dataset and conceptual model upon which a realistic assessment of vulnerability for various areas can be derived. The study will focus on the Buffalo River Basin and an eight-county area of northwestern Arkansas (Benton, Washington, Carroll, Madison, Boone, Newton, Marion, and Searcy counties), and in selected areas in the Ozark National Scenic Riverways in southern Missouri. Concurrent activities as part of the study include:

  • Compile all ground-water nitrate data for the study area.
  • Compile geologic maps for eight-county area.
  • Compile and digitize, where necessary, major sources (CAFOs, etc.) and karst features.
  • Field-verify sinkholes identified on maps for the Buffalo River watershed.
  • Sample selected springs within Buffalo River watershed for nutrients (primarily nitrate), major ions and trace metals.