Doctoral Dissertation Research: Hydrologic and Geochemical Response of Conduit- and Diffuse-Flow Karst Systems to Variable Seasonal Climate and Individual Storm Characteristics

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Karst landscapes develop predominately through processes of solution, as ground water dissolves limestone, dolomite, or other soluble rocks. One of the most significant questions confronting karst studies is why humid tropical karst terrains are more accentuated and more varied in landform styles than are karst landscapes of cooler environments. Different stages of development, climate, carbon dioxide in soils, geologic structure and lithology, and runoff all have been suggested as explanations. This doctoral dissertation research project will examine the role that the hydrologic and geochemical characteristics of aquifers play in the removal of material by ground water through the analysis of two different kinds of aquifers located in close proximity to each other. The Lost Cove of southeastern Tennessee has an aquifer dominated by highly concentrated conduits through which ground water flows, while ground water movement in the Pocket Branch valley of northwestern Georgia is highly diffused through the aquifer. Networks of environmental monitoring stations will be established in the two study area, with regular records of climate, hydrology, and soil and water chemistry taken by automatic sensors or through repeated field observations. The data collected with these monitors will be analyzed to more fully define the major hydrologic and geochemical differences between conduit-flow and diffuse-flow karst systems in response to seasonal climate variations and individuals storms. The results will help identify which flow system removes material more rapidly and will explain why and when removal occurs. This research also should help determine which system sequesters greater amounts of carbon, thereby increasing its capacity to serve as a buffer against increasing carbon dioxide in the atmosphere. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.