Western Kentucky University
Geological and hydrogeological “red flags” that influence land-use hazards in karst: a case study in Warren County, Kentucky
Grade Level at Time of Presentation
Sophomore
Major
Geology
Institution 23-24
Western Kentucky University
KY House District #
15
KY Senate District #
3
Faculty Advisor/ Mentor
Patricia Kambesis, Ph.D
Department
Earth, Environmental, and Atmospheric Sciences
Abstract
Sinkhole flooding and collapse, and impaired groundwater quality are characteristic land-use hazards in karst landscapes. The karstic Lost River groundwater basin (LRGB), Warren County, Kentucky, is the site of two infamous sinkhole collapses, numerous cover collapses, significant sinkhole flooding, and breaches in groundwater quality. This study documented and analyzed the geological and hydrogeological “red flags” making areas within LRGB more susceptible to such hazards. A simple rubric was constructed for preliminary assessment of karst land-use risk. In a case study, we assessed the potential for karst hazards in an undeveloped area of LRGB recently re-zoned from agricultural to residential land-use. Assessment methods included speleological and geological mapping, field observations, and GIS/LIDAR landform analysis.
Speleological mapping revealed an undocumented cave system, established its relationship to surface topography, and quantified thickness of rock/soil overburden above the cave. Geological mapping documented faulting and joint-control that influenced cave extent/footprint, and bedrock characteristics impacting groundwater flow. Field observations identified underground zones where surface sediments and debris (natural and man-made) accumulated causing impact to groundwater flow. Direction of groundwater flow in the cave system and proximity of significant springs outside of LRGB suggested the area of interest was not part of LRGB but of an undocumented groundwater basin. Landform analysis using GIS/LIDAR revealed pre-existing sinkholes making the area prone to future collapses and flooding.
Evaluation of assessment data with the risk-hazard rubric showed the undeveloped area to be at high risk for karst land-use hazards and informed recommendations for additional assessments and more detailed risk-analysis.
Geological and hydrogeological “red flags” that influence land-use hazards in karst: a case study in Warren County, Kentucky
Sinkhole flooding and collapse, and impaired groundwater quality are characteristic land-use hazards in karst landscapes. The karstic Lost River groundwater basin (LRGB), Warren County, Kentucky, is the site of two infamous sinkhole collapses, numerous cover collapses, significant sinkhole flooding, and breaches in groundwater quality. This study documented and analyzed the geological and hydrogeological “red flags” making areas within LRGB more susceptible to such hazards. A simple rubric was constructed for preliminary assessment of karst land-use risk. In a case study, we assessed the potential for karst hazards in an undeveloped area of LRGB recently re-zoned from agricultural to residential land-use. Assessment methods included speleological and geological mapping, field observations, and GIS/LIDAR landform analysis.
Speleological mapping revealed an undocumented cave system, established its relationship to surface topography, and quantified thickness of rock/soil overburden above the cave. Geological mapping documented faulting and joint-control that influenced cave extent/footprint, and bedrock characteristics impacting groundwater flow. Field observations identified underground zones where surface sediments and debris (natural and man-made) accumulated causing impact to groundwater flow. Direction of groundwater flow in the cave system and proximity of significant springs outside of LRGB suggested the area of interest was not part of LRGB but of an undocumented groundwater basin. Landform analysis using GIS/LIDAR revealed pre-existing sinkholes making the area prone to future collapses and flooding.
Evaluation of assessment data with the risk-hazard rubric showed the undeveloped area to be at high risk for karst land-use hazards and informed recommendations for additional assessments and more detailed risk-analysis.