Title page for ETD etd-07262010-133526


Type of Document Master's Thesis
Author Gerst, Jonathan Daniel
URN etd-07262010-133526
Title Epikarst control on flow and storage at James Cave, VA: an analog for water resource characterization in Shenandoah Valley karst
Degree Master of Science
Department Geosciences
Advisory Committee
Advisor Name Title
Schreiber, Madeline E. Committee Chair
Schwarz, Benjamin F. Committee Co-Chair
Burbey, Thomas J. Committee Member
Rimstidt, James Donald Committee Member
Keywords
  • epikarst
  • karst aquifer
  • groundwater
  • watershed management
Date of Defense 2010-07-12
Availability unrestricted
Abstract
Karst aquifers host significant water supplies but are easily contaminated because highly conductive inlets can rapidly transmit water to depth. The epikarst, which is the region of vegetation, soil, and weathered bedrock above karst aquifers, is a critical zone as it regulates the quantity and quality of recharge to the aquifer. As the epikarst exhibits complex heterogeneity, characterization at the field scale can be challenging. The objective of this thesis was to develop a model of epikarst hydrodynamics using longterm field measurements. To meet this objective, continuous hydrologic data of precipitation, speleothem drips, and an underground stream in James Cave in Pulaski County, VA, were collected to delineate seasonal recharge patterns, estimate effective recharge and catchment areas, characterize the number and permeability of flow paths, and evaluate storativity in the epikarst.

Results demonstrate that after significant seasonal recharge, which occurs in the late winter and early spring, the epikarst can temporarily store a significant portion of recharge in low permeability flow paths. Effective recharge was estimated to be approximately 30% of total precipitation (2008-2009). Hydrograph recession analysis

aided in delineation of flowpaths in the epikarst, including quickflow, moderate flow, and

baseflow components. Hydrograph shape analysis suggests flow restrictions at two of the drip sites that may reveal spatial differences in storage capacity and retention time. Results of this work are intended to aid karst aquifer management by providing a multitechnique approach that can be used to assess seasonal patterns of recharge, quantify flowpath and storage characteristics, and delineate recharge zones.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Gerst_JD_T_2010.pdf 1.12 Mb 00:05:11 00:02:40 00:02:20 00:01:10 00:00:05

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.