Submitted to: USGS Karst Interest Group Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/10/2005
Publication Date: 9/12/2005
Citation: Groves, C., Bolster, C.H., Meiman, J. 2005. Spatial and temporal variations in epikarst storage and flow in south central kentucky's pennyroyal plateau sinkhole plain. USGS Karst Interest Group Conference Proceedings. Interpretive Summary:
Technical Abstract: The well-developed karst aquifers of south central Kentucky’s Pennyroyal Plateau are impacted by contamination from animal waste and other agricultural inputs. Understanding fate and transport of these and other contaminants first requires knowledge of flow and storage behaviors within the impacted aquifers, complicated by typically significant heterogeneity, anisotropy, and rapid temporal variations. Here we report on spatial and temporal variations in vadose zone flow behavior within Cave Spring Caverns, Kentucky beneath agricultural lands on a well-developed sinkhole plain. Weekly measurements of three underground waterfalls show statistically significant differences in water quality, though the sites are laterally within 160 m and at about the same depth underground, in a groundwater basin of over 315 km2. These reflect a combination of differences in epikarst flow and land use above the cave. High-resolution (minutes) monitoring of precipitation recharge along with flow and specific conductance in one of the waterfalls reveals a significant storage and mixing reservoir within the soil/epikarst zone. Varying recharge rates and antecedent moisture conditions result in a range of storm responses observed at the waterfall, depending in part on whether this reservoir is filled or depleted. Diffuse and rapid flows through this storage zone were observed, the latter triggered by high recharge rates. These observations are generally consistent with the interpretations of Perrin and others (2003) from a Swiss limestone aquifer in a somewhat different hydro geologic setting, strengthening the idea that epikarst and, more generally, vadose zone storage play a key role influencing flow and transport within karst aquifer systems.