Groundwater and Surface Water Flow Through Preferential-Flow Channels in Karst Terrains
Presented on Wednesday, March 18, 2015
Ronald Green, Ph.D., PG1, Paul Bertetti, P.G.2, Beth Fratesi1, Marcus Gary, Ph.D., P.G.3, Kevin Urbanczyk, Ph.D.4 and Jeffery Bennett, P.G.5, (1)Earth Science Section, Southwest Research Institute, San Antonio, TX, (2)Geosciences and Engineering Division, Southwest Research Institute, San Antonio, TX, (3)Aquifer Science, Edwards Aquifer Authority, San Antonio, TX, (4)Sul Ross State University, Alpine, TX, (5)National Park Service, Alpine, TX
Field studies and supporting analyses provide valuable insights on the relationship of groundwater to surface water in terrains comprised of karstic limestone located in semi-arid and sub-humid environments. Stream gain/loss studies coupled with geophysical surveys of the Devils River watershed in south-central Texas provide a sound basis to ascertain where groundwater is discharged to surface water and where significant conveyance of groundwater occurs in subsurface preferential flowpaths coincident with river channels. These studies and analyses support a conceptualization of surface water and groundwater flow interaction within a large watershed wherein significant quantities of groundwater are conveyed to springs and streams along relatively narrow flowpaths. These flowpaths are localized along zones of increased permeability that developed by enhanced dissolution coincident with river channels. Potential impacts of management decisions on the water resources of the Devils River watershed in central Texas are evaluated based on this conceptualization of the surface water and groundwater flow regimes in a semi-arid environment. Evidence is presented that suggests the same principles can be extended to sub-humid environments.
Ronald Green, Ph.D., PG
Earth Science Section, Southwest Research Institute, San Antonio, TX
Dr. Ronald Green is an Institute Scientist in the Geosciences and Engineering Division at Southwest Research Institute in San Antonio, Texas where he has worked for the past 25 years. His primary activities are in groundwater hydrology and environmental geophysics. Recent work has focused on water availability in south-central and west Texas and the impact of oil and gas activities on water resources. Of particular interest are the water resources of karst limestone aquifers including assessments of recharge, characterization of flow mechanisms, and numerical modeling. Dr. Green is a Fellow in the Geological Society of America and is certified as a Professional Geologist in Texas. He holds a B.S. in Industrial Engineering from the University of Michigan, a B.S. in Geology from Grand Valley State University, a M.S. in Geophysics from the University of Utah, and a Ph.D. in Hydrology from the University of Arizona.
Paul Bertetti, P.G.
Geosciences and Engineering Division, Southwest Research Institute, San Antonio, TX
Paul Bertetti, PG, is a water chemist.
Beth Fratesi
Earth Science Section, Southwest Research Institute, San Antonio, TX
Beth Fratesi, Ph.D., is a hydrogeologist specializing in numerical modeling of karst groundwater systems.
Marcus Gary, Ph.D., P.G.
Aquifer Science, Edwards Aquifer Authority, San Antonio, TX
Marcus Gary is a karst scientist who specializes in conducting hydrogeologic investigations to expand the understanding of karst forming processes, and study the implications that karst geology has on natural resource management. Gary received his Ph.D. in hydrogeology from the Jackson School of Geosciences at the University of Texas at Austin in 2009, and a B.S. degree from the same institution in 2001. He worked for eight years as a hydrologist for the U.S. Geological Survey, four years in environmental consulting, and is now currently a senior hydrogeologist for the Edwards Aquifer Authority in San Antonio, Texas.
Kevin Urbanczyk, Ph.D.
Sul Ross State University, Alpine, TX
Kevin Urbanczyk, Ph.D., is a Professor at Sul Ross State University.
Jeffery Bennett, P.G.
National Park Service, Alpine, TX
Jeffery Bennett, PG, is a Physical Scientist/Hydrologist.
