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1
Hobbs, S. L. "Recharge, flow and storage in the saturated zone of the Mendip limestone aquifer." Thesis, University of Bristol, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234811.
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Ellaway, Edward Mark. "A study of the hydrochemistry of a limestone area : Buchan, East Gippsland /." Connect to thesis, 1991. http://repository.unimelb.edu.au/10187/1504.
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This thesis reports the results obtained, and conclusions made regarding research into the hydrochemistry of a small impounded karst area in southeastern Australia. Water samples were collected from a variety of sites over a period of approximately six years and include samples that are representative of baseflow (drought conditions) and flood (high flow conditions) the two extremes of the flow regime. Four distinct water types were found to be associated with the karst spring and cave water sites sampled. In terms of physical, chemical and computed parameter values these have been classed as TYPE 1 water (median parameter values similar to those noted for the surface stream sites sampled with catchments of non-carbonate material); TYPE 2 water (catchment predominantly of limestone); TYPE 3 water (catchment predominantly of dolomite); TYPE 4 water (high median chemical concentrations). Spatial variation within the study area is considerable and intrinsic factors such as catchment lithology, the residence time of recharge, aspect and vegetation cover are the major natural controls in determining physical and chemical characteristics.
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Kaletsky, Kelly. "Measurement of the Effects of Food Preparation Activities on the Microclimate of the Snowball Dining Room Area of Mammoth Cave." TopSCHOLAR®, 1992. http://digitalcommons.wku.edu/theses/1734.
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The stability of Mammoth Cave’s microclimate has never undergone extensive investigation. The Snowball Dining Room area was chosen to measure the microclimate of the cave and to determine if food preparation, human presence and surface temperature variations alter this microclimate. Three portable weather stations containing a temperature / humidity probe, datalogger and microbarograph were placed in various locations along three passageways leading away from the dining room. Readings were taken 24 hours per day for four months. Plotting temperature readings in graph form show a correlation between temperature of the passageway and distance from the dining room.
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Miller, Benjamin Verlinden. "The Hydrology of the Carroll Cave-Toronto Springs System: Identifying and Examining Source Mixing through Dye Tracing, Geochemical Monitoring, Seepage Runs, and Statistical Methods." TopSCHOLAR®, 2010. http://digitalcommons.wku.edu/theses/216.
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In karst areas relationships between activities occurring on the surface and the overall health of the subsurface environment are often highly interconnected. However, the complex nature of karst flow systems can often make identification of these connections difficult. Carroll Cave, a large stream cave system located in the central Missouri Ozarks, is known for its biological and speleological significance. A dye tracing project to delineate a Carroll Cave recharge area through dye tracing has identified an area of 18.5 km2 which contributes water to the cave. The water from Thunder River within Carroll Cave was positively traced to eight springs of the thirteen springs at a distributary spring system known as Toronto Springs. Through examination of the geochemistry of the individual springs, differences in water chemistry between the various outlets has become evident. Additional work with YSI Sonde dataloggers and consideration of carbonate chemistry relationships has sought to further define the variations in hydrochemical behavior, thus aiding in the discrimination potential spring sources. Primary sources thought to contribute water to the spring system include Carroll Cave and Wet Glaize Creek, with some minor influence from other losing streams in the vicinity. Seepage runs along Wet Glaize Creek have also identified major losing reaches, in close proximity to structural features, which may contribute water to Toronto Springs. Examination of the measured parameters and derived have identified that Carroll Cave and Wet Glaize Creek are the primary end members for Ca2+, Mg2+, HCO3-, specific conductance, and temperature. Using these parameters a two end member mixing model has been developed which describes the mixing zone setting at Toronto Springs and calculates the average proportions of flow contributions by the end members. By using a multi-proxy approach of dye tracing, seepage runs, and geochemistry for the individual springs, the source waters and pathways for the springs at Toronto Springs have been identified.
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Croskrey, Andrea. "Hydrolgeologic Groundwater Sensitivity and Vulnerability Mapping in South Central Kentucky." TopSCHOLAR®, 2006. http://digitalcommons.wku.edu/theses/450.
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Groundwater sensitivity (Ray and O'dell 1993 a) refers to the inherent ease with which groundwater can be contaminated based on hydrogeologic characteristics. We have developed digital methods for identifying areas of varying groundwater sensitivity for a ten county area of south-central Kentucky relevant to a scale of 1: 24,000. The study area includes extensive limestone karst sinkhole plains, with groundwater that is generally extremely sensitive to contamination. Digitally Vectorized Geologic Quadrangles (DVGQs) were combined with elevation data to both identify hydrogeologic groundwater sensitivity regions and to identify zones of "high risk runoff where contaminants could be transported in runoff from less sensitive to higher sensitivity (particularly karst) areas. This analysis was limited to existing, available digital data sources. While future work will fine-tune these maps with additional layers of data (soils for example) as digital data become available, using DVGQs this method is allowing a relatively rapid assessment of groundwater sensitivity for Kentucky at a larger scale than previously available.
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Reece, Matthew A. "Origin and morphology of notches in carbonate cliffs and hillslopes implications for paleoclimate and paleohydrology /." Master's thesis, Mississippi State : Mississippi State University, 2004. http://library.msstate.edu/etd/show.asp?etd=etd-03102004-105006.
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Ek, David. "Hydrologic and Geochemical Cycling within Karst Versus Non-Karst Basins within the Interior Low Plateau Province of South-Central Kentucky." TopSCHOLAR®, 2004. http://digitalcommons.wku.edu/theses/550.
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This thesis summarizes my research in which I investigated differences and characteristics in hydrologic, nutrient and geochemical cycling between karst versus nonkarst basins within the Interior Low Plateau Province. Field data including stream discharge, evapotranspiration, and dissolved major ion concentrations were collected for a period of one year for two basins within Mammoth Cave National Park. Twelve percent carbonate rocks underlie one basin, while the other consists of 48 percent carbonate rocks. The carbonate rock exposures within both basins exhibit karstification. The hydrologic and geochemical differences between these basins were compared to determine to what extent that cycles are modified or altered within karst terrains. The characteristics of these cycles within both basins were also compared. I found that there were noticeable hydro geochemical effects from the presence of karst within a basin. These effects were either the result of the presence of carbonate rocks within the basin or due to the presence of morphological karst features within the carbonate rocks. The presence of karst serves as a buffer by moderating temperature extremes, lessens the effect of acid precipitation, moderates discharges during storm surges, moderates/lessens a basin's evaporative losses, and affects available moisture and nutrients to surface biological processes. These hydrologic effects in turn, also continue to affect the basin's geochemistry in noticeable ways. Findings included that it only takes a small percentage of carbonate rocks within a basin to produce an output stream with a calcium/bicarbonate geochemical signature. In these situations, the quantity of karst is perhaps not as important as spatial distribution. Therefore, the quantity of karst within a basin may be more critical to accurately assess when conducting geochemical modeling. Many global geochemical models do not factor in karst affects (Holmen, 1992). Considering the extent of carbonate rocks globally and their potential ability to affect hydrogeochemical cycles, future model modifications may need to factor in karst affects in order to more accurately represent actual real-world field conditions.
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Merideth, Johnny. "Vadose Zone Hydrology near the Vicinity of Edna's Dome, Mammoth Cave, Kentucky." TopSCHOLAR®, 2009. http://digitalcommons.wku.edu/theses/65/.
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Wright, Winfield G. "Modeling karst aquifer response to rainfall." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/76043.
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A finite-element model (HYDMATCH) uses spring hydrograph discharge data to generate a linear regression relation between fracture conductivity and potential gradient in a karst aquifer system. Rainfall excess in the form of potential energy from sinkhole sub-basins is input to element nodes and routed through a one-dimensional finite-element mesh to the karst spring represented by the last node in the finite element mesh. A fracture-flow equation derived from the Navier-Stokes equation uses fracture conductivities from the regression equation and potential gradient in the last element of the mesh to determine discharge at the spring.
Discharge hydrograph data from Nininger spring, located in Roanoke, Virginia, was used to test the performance of the model. Excess from a one-half inch rain was introduced into sinkhole nodes and the regression equation generated by matching discharges from the known hydrograph for the one-half inch rainfall. New rainfall excess data from a one-inch rainfall was input to the sinkhole nodes and routed through the finite-element mesh. The spring hydrograph for the one-inch rainfall was calculated using the regression equation which was determined previously. Comparison of the generated hydrograph for the one-inch rainfall to a known hydrograph for a one-inch rainfall shows similar shapes and discharge values.
Areas in need of improvement in order to accurately model ground-water flow in karst aquifers are a reliable estimate of rainfall excess, a better estimation of baseflow and antecedent aquifer conditions, and the knowledge of the karst aquifer catchment boundaries. Models of this type may then be useful to predict flood discharges and contaminant travel times in karst aquifers.Master of Engineering
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Dogwiler, Toby J. "Fluvial disturbances in karst streams /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3060093.
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Menning, Damian M. "Karst Estuaries: A newly described ecosystem governed by aquifer hydrology." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5382.
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The overall goal of this dissertation is to define the hydrological, geochemical, and biological characteristics of a Karst Estuary. These types of estuaries represent a unique ecosystem created by freshwater inputs from direct flow through karst conduits and/or diffuse flow through a karst matrix. In order to determine the characteristics of a Karst Estuary we monitored short-term tidal fluctuations, long-term rainfall patterns, aquifer levels, spring discharge, multiple geochemical parameters, microbial communities in the water column and sediment, and macrofaunal communities in the sediment along a transect from a submarine spring through the Gulf of Mexico. Four sites were selected along a spring/marine transect and one nearby freshwater spring was used as a reference site. Datasondes were deployed in the nearshore brackish submarine spring to measure discharge volume, tidal fluctuations, and physical water parameters for two years. Water column and sediment samples were collected quarterly from both springs and the surrounding surface sites over the same time period. An isotopic/trace element mass balance method was used to determine the hydrogeological conditions of the spring discharge with three possible sources: 1) freshwater from the upper portion of the Upper Floridan aquifer, 2) freshwater from the lower portion of the Upper Floridan aquifer, and 3) saltwater from the Gulf of Mexico. Archaea, Bacteria, and microbial eukaryote communities were analyzed using molecular techniques, and macrofauna communities were determined using light microscopy. Correlation analyses were conducted to compare all studied biological communities to the hydrological and geochemical data in order to determine the influence of aquifer discharge. Within the water column of the submarine spring conduit, there were no significant differences of the sampled parameters over short sampling distances (m) and periods (hr). Spring discharge was found to be negatively correlated with tidal level and directly correlated with aquifer level. The brackish nature of the spring discharge is primarily due to simple mixing between the Gulf of Mexico saltwater and freshwater from the lower portion of the Upper Floridan aquifer originating from the mixing zone beneath the estuary. The composition of the spring discharge varied seasonally, showing increased marine influence at the beginning of the wet season. Tropical Storm Debby, June 2012, resulted in measurable freshwater inputs to spring discharge from the upper portion of the Upper Floridan aquifer. The number of spring reversals (salt water intrusion events) increased as the dry season progressed, stopped reversing immediately after Tropical Storm Debby, and then gradually increased into the next dry season. Statistically significant geochemical differences were found along the spring/marine transect on each collection date and seasonally at the individual sites. The major finding was that the primary driver of change in all of the studied biological communities of this Karst Estuary is the volume of aquifer discharge and the gradients formed by aquifer discharge and not the geochemical fluctuations within the system. Events that result in shifting the mixing zone inland have dramatic impacts on the biological communities of these environments. Karst Estuaries are a newly discovered type of ecosystem that are different from surface estuaries in that they are formed by aquifer discharge which is more stable in terms of geochemistry than water discharged to the sea via surface rivers.
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Auler, Augusto. "Hydrogeological and Hydrochemical Characterization of the Matozinhos-Pedro Leopoldo Karst, Brazil." TopSCHOLAR®, 1994. http://digitalcommons.wku.edu/theses/927.
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The Matozinhos-Pedro Leopoldo limestone area is a tropical karst located near the metropolis of Belo Horizonte, East Central Brazil, in an area undergoing rapid urbanization and land degradation. Qualitative dye tracing experiments have determined the groundwater routes and catchment areas in the two major drainage basins in the area, Samambaia Basin and Palmeiras-Mocambo Basin. Other drainage basins were identified, but not traced due to the absence of related swallets. Fluorescein and optical brightener had a poor performance as tracers under tropical climate. Dilution due to the existance of lakes at some swallets prevented some dye traces. The water that flows through this karst area is almost entirely autogenic, having a small external contribution from some phyllite areas. About 88% of the total water discharge of identified springs drains directly toward Velhas River, the regional base level. The remaining 12% drains toward Mata Creek, a tributary of the Velhas River. Hydrochemical monitoring in four of the major springs showed that groundwater quality for the measured parameters in the discharge zone is generally good, despite the heavy industrialization and occupation in some of the recharge areas. Conduit flow predominates in Samambaia and Palmeiras- Mocambo Basins. The outlets for these basins show a marked seasonal variation in the physical and chemical parameters monitored. Some of the other springs such as Moinho Velho Spring and Jaguara Spring show little variation in temperature, suggesting a diffuse flow component. All springs are characterized by hardness dilution during the wet season, suggesting a small residence time during the wet season, not allowing the water to achieve saturation. Seasonal variation in runoff is the most important control on the hydrochemical pattern of the area. It determines the marked dilution of major ions in both conduit-flow and diffuse-flow springs. Variation in soil C02 due to the rainfall pattern may also play an important role in the water chemistry. Observation of paleoflow indicators made in several dry caves showed that the past flow pattern at Palmeiras-Mocambo Basin agrees with the present groundwater routes. At Samambaia Basin, however, the lower reaches of the basin show paleoflow directions pointing toward other active base levels such as Mocambeiro Depression or Velhas River, suggesting that Samambaia Basin may have developed its present morphology in a later stage.
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Pierskalla, William P. Jr. "RETHINKING KARST HAZARD ASSESSMENT IN KENTUCKY." UKnowledge, 2019. https://uknowledge.uky.edu/ees_etds/67.
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Current karst hazard maps in Kentucky reflect the general lithology of the state and ignore or significantly reduce the impact of the actual sinkholes present within these areas. These maps rely on equal weighting, by area, of the Karst Potential Index (KPI) map and the sinkhole inventory map. The KPI is based on a 1:500,000 geologic map and less than 500 data points of carbonate rocks. The sinkhole inventory is derived from topographic maps updated in the 1970s with approximately 10-foot resolution. This method gives a preferential weighting of the KPI over the sinkhole data. Consequently, the current method is broad in scope and ineffective in hazard assessment. There is a need for a reliable karst hazard map for land use planners, government emergency planning agencies, and other stakeholders. In this study, more detailed geology information and LiDAR (Light Detection and Ranging) data are applied to three counties (Bullitt, Logan, and Woodford) to generate a more accurate assessment of karst hazard. An assessment method based on sinkhole density is also tested. By refining the hazard score to more precise areas of concern, future stakeholders will find this data useful in emergency planning and land assessment.
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Bledsoe, Lee Anne. "An Investigation of Groundwater Flow in the Vicinity of Patoka Dam, Indiana." TopSCHOLAR®, 2015. http://digitalcommons.wku.edu/theses/1539.
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Several dams throughout the United States have been built on karst terrains, where soluble limestone bedrock has been dissolved to form features such as caves, sinkholes, and underground rivers. In such karst regions, subsurface hydrology can play an integral role in the condition, operation, and safety of dams and should be considered during risk assessment. Patoka Dam, near Jasper, Indiana, is situated on a well-developed karst landscape/aquifer system, faces significant potential challenges, and recently underwent risk assessment. A groundwater flow investigation using multiple fluorescent tracer tests, analysis of water-table elevations, isopach mapping of the Glen Dean Limestone, and spring hydrograph analysis was performed to better understand local groundwater hydrology in the vicinity of the existing water-control structures. Dye-tracing results identified the local flow direction as south to north and the mean dye travel time from injection locations to Robert Hall Cave Spring (RHCS) as 8- 11 feet per hour. These results also indicate that groundwater is bypassing the control structures in the vicinity of the cut-off wall, but the geometry of these flow paths is not clear. The recharge area for RHCS, a significant groundwater discharge point downstream from Patoka Dam, was delineated and the existence of a groundwater divide in the area of the dike was confirmed. The location of this groundwater-basin boundary follows an estimation of where the Glen Dean Limestone outcrops along the perimeter of the dissected ridge that lies between Patoka Lake and RHCS. Spring hydrograph analysis shows that spring discharge is primarily influenced by local precipitation events. However, precipitation events can result in increased pool elevation making the relationship between spring discharge and pool elevation unclear within the data set. This groundwater investigation has provided a clearer characterization of the hydrogeology within the vicinity of Patoka Dam. In combining the various hydrogeologic results, some insight into the function and geometry of the local karst network that could potentially affect the integrity of the dam and/or dike structures has been provided.
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Eberhard, Stefan M. "Ecology and hydrology of a threatened groundwater-dependent ecosystem : the Jewel Cave karst system in Western Australia /." Access via Murdoch University Digital Theses Project, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20051010.141551.
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Kambesis, Patricia. "Agricultural Contaminant Source and Transport in a Karst Groundwater Basin." TopSCHOLAR®, 2007. http://digitalcommons.wku.edu/theses/426.
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Agricultural land use in areas that are located in karst groundwater basins negatively impact groundwater quality because karst terrains provide multiple, direct hydrologic connections from the surface into karst aquifers. The connections and rapid velocities associated with surface and subsurface flow in karst aquifers allow for contaminants to move quickly into and through a groundwater basin. When groundwater returns to the surface via a spring or springs, any contaminants within the water become part of surface streams and rivers. These in turn, impact water quality in areas located downstream of the spring or springs. The purpose of this study was to identify the source and movement of agricultural contaminants in a karst groundwater basin within the context of local climate, hydrogeology and land use. The study area is a fluvio-karst groundwater basin located in the Corn Belt of northeast Iowa and southeast Minnesota. Land use is predominantly agricultural in nature. Dye tracing, both qualitative and quantitative, resulted in the delineation of the Coldwater Cave Groundwater basin and illustrated that the boundaries of the basin could change as a result of precipitation events. Investigation of basin and aquifer characteristics, stream water temperature monitoring, and evaluation of cave map data and karst feature inventories determined that the surface and subsurface hydrogeology in the study area was very well integrated. Water sampling and analysis documented that agricultural contaminants, specifically nitrates, bacteria, and atrazine impact the quality of the surface water and groundwater within the basin. A ribotyping project that was done in conjunction with the thesis work showed the source of bacteria to be from cattle and humans. Nitrogen isotope analyses indicated that the source of nitrates was from ammonium fertilizers and from septic system wastes. Atrazine, at levels well below the MCL standards established by EPA, and its metabolite deethylatrzine (DEA) were detected in the groundwater year round. Contaminant load was calculated for nitrates, bacteria, and atrazine. Lowest contaminant loads occurred during the winter months of November, December, and January, when freezing temperatures minimized groundwater recharge. Contaminant load varied between high and low concentrations during the months of February and March reflecting the diurnal change between above and below freezing surface temperatures. Contaminant loads were highest during May through October when storm events are common. Contaminant load and transport are a function of the interaction of local hydrogeology and climate.
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Saller, Stephen Paul. "Coupled continuum pipe-flow modeling of karst groundwater flow in the Madison limestone aquifer, South Dakota." Thesis, Colorado State University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1539572.
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Karst carbonate aquifers are traditionally difficult to model due to extreme permeability heterogeneities and non-Darcian flow. New modeling techniques and test applications are needed to improve simulation capabilities for these complex groundwater systems. This study evaluates the coupled continuum pipe-flow framework for modeling groundwater flow in the Madison aquifer near Rapid City, South Dakota. The Madison carbonate formation is an important source of groundwater underlying Rapid City. An existing equivalent porous medium (EPM) groundwater model of the Madison aquifer was modified to include pipe networks representing conduits. In the EPM model, karstified portions of the aquifer are modeled using high hydraulic conductivity zones. This study hypothesized that the inclusion of conduits would allow for a simpler hydraulic conductivity distribution and would improve modeled fits to available data from a 10-year monitoring period. Conduit networks were iteratively fit into the model based upon available environmental and dye tracer test data that approximated major karst pathways. Transient simulation results were evaluated using observation well hydraulic heads and estimated springflow data. In a comparison to the EPM model, the new modeling results show an improved fit to the majority of observation well targets, and negligible impact to springflow data. The flow dynamics of the aquifer model were significantly altered, with the conduit networks acting as gaining or losing subsurface features, behaving as regional sinks during dry periods and flowpath heterogeneities during wet periods. The results of this study demonstrate that the coupled continuum pipe-flow modeling method is viable for use within large regional aquifer models.
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Steinmann, Hali. "Controls on Speleogenesis in the Upper-Mississippian Pennington Formation on the Western Cumberland Plateau Escarpment." TopSCHOLAR®, 2018. https://digitalcommons.wku.edu/theses/3088.
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Much of the pioneering work on caves of the Cumberland Plateau (province spanning Tennessee, Kentucky, Alabama, and Georgia) has been stratigraphically located within the Mississippian Bangor and Monteagle Limestones, wherein some of the region’s largest and most spectacular caves occur. Of interest to the understanding of this karst landscape, but severely underrepresented in the literature thereof, are caves and karst features in a heterogeneous sequence of clastics and carbonates known collectively as the Pennington Formation (Upper Mississippian). This work consisted of a regional study of Pennington caves on the western Cumberland Plateau escarpment (Alabama and Tennessee), and a case study of Pennington caves in Savage Gulf State Natural Area (Grundy County, Tennessee). The objective of this research was to determine controls on speleogenesis in the Pennington Formation, using cave geomorphology, dye tracing, and GIS to explore lithologic, hydrologic, and structural influences on karst processes. This resulted in a conceptual model for speleogenesis in the Pennington Formation, with the major controls being: 1) direct and diffuse recharge from the caprock, undersaturated with respect to calcite; 2) thin, horizontally bedded limestones sandwiched by shales and other insoluble rocks; and 3) networks of stress release fractures oriented parallel to major stream valleys. Our present understanding of the Cumberland Plateau could be advanced by further study of karst dynamics in the Pennington Formation.
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McClanahan, Kegan N. "Carbon Cycling Dynamics Inferred from Carbon Isotope Sourcing in a Mid-Latitude Karst-Influenced River." TopSCHOLAR®, 2014. http://digitalcommons.wku.edu/theses/1393.
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As ever-increasing levels of carbon dioxide alter the chemistry of the Earth’s atmosphere, understanding the global carbon cycle becomes increasingly important. A particularly important component is the riverine carbon cycle, as rivers are the primary conduits for dissolved inorganic carbon from terrestrial watersheds to ocean basins. Stable carbon isotopes (13C/12C) were collected weekly and input into the mixing model IsoSource to delineate seasonal carbon sourcing along two nested basins in the upper Green River System, Kentucky. In the more siliciclastic upstream catchment, dissolved inorganic carbon (DIC) was primarily derived from soil respiration (34%). Groundwater dissolving carbonate bedrock and carbonate dissolution/precipitation reactions contributed 31% and 11%, respectively. The more carbonate-dominated downstream catchment also was influenced greatly by soil respiration (35%). Due to the more pronounced levels of carbonate bedrock, carbonate reactions contributed double that of the upstream catchment (20%), with groundwater contributing 22%. Seasonally, the upstream basin gathered most DIC from soil respiration from late spring to winter. Early spring precipitation and still limited photosynthesis caused the primary carbon sourcing to shift to groundwater. Downstream, the primary source throughout the entire study period was soil respiration. Collectively, this study provides insight into the carbon cycling process in a mid-latitude, karstic river using carbon isotope sourcing to aid in the quantification of global carbon flux in the critical zone.
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Malloy, Elizabeth. "Trophic Dynamic Interactions in a Temperate Karst River." TopSCHOLAR®, 2014. http://digitalcommons.wku.edu/theses/1437.
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Surface streams in karst landscapes are often characterized by high nutrient levels due to incomplete filtration through series of innumerable, below-ground conduits. Seasonal growth of the filamentous alga, Cladophora, is typically associated with nutrient-rich waters. This research compared macroinvertebrate food web structure between riverine reaches with contrasting underlying karst topography, nutrient levels, and Cladophora cover during summer 2012 and autumn 2013. Recent work in these reaches found a high correlation between Cladophora cover and nutrient content, particularly nitrate. Four questions were addressed during this study: 1. Do longitudinal trends in algal and consumer δ13C values relate to decreased DIC availability in larger watersheds? 2. Are trophic niche breadths narrower in more karstified reaches than in less karstified reaches due to longitudinal differences in Cladophora standing stocks? 3. Do differences in trophic-dynamic relationships between primary consumers and their food resources reflect the marked distinction in Cladophora standing stocks in two sections of the upper Green River that flow through differing levels of karstification? 4. Are consumers assimilating primarily autochthonous or allochthonous food resources? Consumers and algae became more 13C-depleted in downstream reaches, which is opposite to published data in other streams. Underlying causes for this pattern are uncertain, but one plausible cause is an increase in DIC availability downstream. Karstrelated hydrology may potentially alter or even reverse normal longitudinal gradients within in-stream producer and subsequently, consumer δ13C values. Since consumers were sampled during low-Cladophora conditions during 2013 and within a few weeks of the onset of the Cladophora bloom in 2012, stable isotopic results may be more representative of primary consumer diets during pre- Cladophora bloom periods. Although Cladophora cover was significantly higher in downstream reaches during both years, food-web structure was similar in all reaches. Consumer niche breadth was similar across reaches, and mixing model analyses suggested that primary consumers in all reaches assimilated similar amounts of Cladophora. The contribution of both autochthonous and allochthonous food resources to the assimilated diet of primary consumers appeared to be similarly important. These results suggest that allochthonous resources may be important in some midreach food webs, especially during periods of low algal growth.
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Hall, Andrew Wesley. "Verification of and Expansion Upon the Use of Cave Scallops in Recreating Hydrogeologic Conditions in Karst Aquifers." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1554989185960227.
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Leyland, R. C. "Vulnerability mapping in karst terrains, exemplified in the wider Cradle of Humankind World Heritage Site." Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-02112009-171849/.
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Slifer, Dennis. "Evaluation of spontaneous potential for monitoring groundwater movement in karst terrain." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/101321.
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Spontaneous potential (SP) is a geophysical method that measures naturally occurring voltage in the earth. Negative anomalies arise from electrokinetic, or streaming potential, effects resulting from the flow of groundwater. In this study SP was monitored at sites in karst terrain in Virginia. The results were evaluated for effectiveness in detecting groundwater flow paths and rates. The ability of SP to distinguish between diffuse flow and conduit flow was examined. Soil temperature, soil moisture, and precipitation are major variables influencing SP data. An automated data collection system was devised and used for long term monitoring of SP changes and environmental variables and for measuring SP changes induced by artificial recharge of water into a sinkhole. Results were evaluated by comparison with geological observations, electrical resistivity, stream flow measurements, and speleological surveys. SP can effectively locate and track shallow groundwater flow paths in karst terrain. A relationship was observed between SP and changes in flow rate where the flow was through porous material, but SP could not be directly related to flow through solutional conduits. However, conduits may be indicated by SP anomalies where soil moisture is drawn into fractures that supply water to conduits. The influence of geologic structure must be considered in, interpreting SP results in karst. Refinement of the SP technique is promising for applications to environmental and geotechnical problems.M.S.
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Jackson, Leah. "Epikarst Hydrogeochemical Changes in Telogenetic Karst Systems in South-central Kentucky." TopSCHOLAR®, 2017. https://digitalcommons.wku.edu/theses/2018.
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Telogenetic epikarst carbon sourcing and transport processes and the associated hydrogeochemical responses are often complex and dynamic. Among the processes involved in epikarst development is a highly variable storage and flow relationship that is often influenced by the type, rate, and amount of dissolution kinetics involved. Diffusion rates of CO2 in the epikarst zone may drive hydrogeochemical changes that influence carbonate dissolution processes and conduit formation. Most epikarst examinations of these defining factors ignore regional-scale investigations in favor of characterizing more localized processes. This study aims to address that discrepancy through a comparative analysis of two telogenetic epikarst systems under various land uses to delineate regional epikarst behavior characteristics and mechanisms that influence carbon flux and dissolution processes in south-central Kentucky. High-resolution hydrogeochemical and discharge data from multiple data loggers and collected water samples serve to provide a more holistic picture of the processes at work within these epikarst aquifers, which are estimated to contribute significantly to carbonate rock dissolution processes and storage of recharging groundwater reservoirs on the scale of regional aquifer rates. Data indicate that, in agricultural settings, long-term variability is governed by seasonal availability of CO2, while in urban environments extensive impermeable surfaces trap CO2 in the soil, governing increased dissolution and conduit development in a heterogonous sense, which is often observed in eogenetic karst development, as opposed to bedding plane derived hydraulic conductivity usually observed in telogenetic settings. These results suggest unique, site-specific responses, despite regional geologic similarities. Further, the results suggest the necessity for additional comparative analyses between agricultural settings and urban landscapes, as well as a focus on carbon sourcing in urban environments, where increased urban sprawl could influence karst development
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Bahr, Kirsten. "Structural and Lithological Influences on the Tony Grove Alpine Karst System, Bear River Range, North Central Utah." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/5015.
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The fracture-dominated Tony Grove alpine karst system in the Bear River Range in north-central Utah, has caves ranging from 5m deep, consisting of solution-enlarged single fractures, to the large, 374m deep, Main Drain Cave, characterized by a series of vertical drops and horizontal passages. The caves int he Tony Grove area are developed throughout the 510m thick Fish Haven and Laketown Dolomites. The Swan Peak Formation, consisting of orthoquartzite and shale, underlies the dolomites.
Surface fracture measurements (n=3502) yielded two distinctive sets of fractures. The northeast-southwest sets had a mean orientation of 41±0.7°
and the northwest-southeast set with a mean of 133±5°. Of the sixteen caves surveyed for fractures and passages, fifteen were controlled by fractures, although some caves had both facture-and non-fracture-controlled passages. Only one cave was entirely non-fracture controlled, likely due to a change in lithology.
Main Drain Cave, the only cave with long horizontal passages, was surveyed for both fracture and stratigraphic influences on horizontal cave development. Results indicate some sections are controlled by southeast-trending-fractures and other sections are controlled by southwest-dipping-bedding planes. Alternatively, parts of the down-dip-oriented sections may be influenced by southwest-oriented fractures. Stratigraphic control in this cave includes cherty layers that appear to hinder down-cutting of passages into lower stratigraphic units.
Surface mapping determined that there is a southeast-oriented fold pair east of the Logan Peak Syncline, consisting of the Naomi Peak Syncline and the Cottonwood Canyon Anticline. The anticline merges with the Logan Peak Syncline near the head of Cottonwood Canyon. The Naomi Peak Syncline continues north-northeast through the Tony Grove area and may divert water from the Tony Grove area to Wood Camp Hollow Spring in Logan Canyon. The anticline acts as a divide between groundwater traveling southwest to Dewitt Spring and south-southeast to Wood Camp Hollow Spring. The Swan Peak Formation appears to act as a barrier to groundwater movement into the underlying formations, separating the Tony Grove system from underlying systems.
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Shelley, James Adam. "Monitoring and Evaluating the Influences of Class V Injection Wells on Urban Karst Hydrology." TopSCHOLAR®, 2018. https://digitalcommons.wku.edu/theses/3086.
Full textAbstract:
The response of a karst aquifer to storm events is often faster and more severe than that of a non-karst aquifer. This distinction is often problematic for planners and municipalities, because karst flooding does not typically occur along perennial water courses; thus, traditional flood management strategies are usually ineffective. The City of Bowling Green (CoBG), Kentucky is a representative example of an area plagued by karst flooding. The CoBG, is an urban karst area (UKA), that uses Class V Injection Wells to lessen the severity of flooding. The overall effectiveness, siting, and flooding impact of Injection Wells in UKA’s is lacking; their influence on groundwater is evident from decades of recurring problems in the form of flooding and groundwater contamination. This research examined Class V Injection Wells in the CoBG to determine how Injection Well siting, design, and performance influence urban karst hydrology. The study used high-resolution monitoring, as well as hydrologic modeling, to evaluate Injection Well and spring responses during storm and baseflow conditions. In evaluating the properties of the karst aquifer and the influences from the surrounding environment, a relationship was established between precipitation events, the drainage capacity of the Injection Wells, and the underlying karst system. Ultimately, the results from this research could be used to make sound data-driven policy recommendations and to inform stormwater management in UKAs.
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Whitelaw, A. S. "Hydrological modelling using variable source areas." Thesis, University of Bristol, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384524.
Full text
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Burrell, Jennifer Lynn. "Water Table Variability on the Pitted Karst Plain, Yucatán, Mexico." Kent State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=kent1322417324.
Full text
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Evans, Jason Peter, and jason evans@yale edu. "Modelling Climate - Surface Hydrology Interactions in Data Sparse Areas." The Australian National University. Centre for Resource and Environmental Studies, 2000. http://thesis.anu.edu.au./public/adt-ANU20020313.032142.
Full textAbstract:
The interaction between climate and land-surface hydrology is extremely important in relation to long term water
resource planning. This is especially so in the presence of global warming and massive land use change, issues which
seem likely to have a disproportionate impact on developing countries. This thesis develops tools aimed at the study
and prediction of climate effects on land-surface hydrology (in particular streamflow), which require a minimum
amount of site specific data. This minimum data requirement allows studies to be performed in areas that are data
sparse, such as the developing world.
¶
A simple lumped dynamics-encapsulating conceptual rainfall-runoff model, which explicitly calculates the evaporative
feedback to the atmosphere, was developed. It uses the linear streamflow routing module of the rainfall-runoff model
IHACRES, with a new non-linear loss module based on the Catchment Moisture Deficit accounting scheme, and is referred
to as CMD-IHACRES. In this model, evaporation can be calculated using a number of techniques depending on the data
available, as a minimum, one to two years of precipitation, temperature and streamflow data are required. The model
was tested on catchments covering a large range of hydroclimatologies and shown to estimate streamflow well. When
tested against evaporation data the simplest technique was found to capture the medium to long term average well but
had difficulty reproducing the short-term variations.
¶
A comparison of the performance of three limited area climate models (MM5/BATS, MM5/SHEELS and RegCM2) was conducted
in order to quantify their ability to reproduce near surface variables. Components of the energy and water balance
over the land surface display considerable variation among the models, with no model performing consistently better
than the other two. However, several conclusions can be made. The MM5 longwave radiation scheme performed worse than
the scheme implemented in RegCM2. Estimates of runoff displayed the largest variations and differed from observations
by as much as 100%. The climate models exhibited greater variance than the observations for almost all the energy and
water related fluxes investigated.
¶
An investigation into improving these streamflow predictions by utilizing CMD-IHACRES was conducted. Using
CMD-IHACRES in an 'offline' mode greatly improved the streamflow estimates while the simplest evaporation technique
reproduced the evaporative time series to an accuracy comparable to that obtained from the limited area models alone.
The ability to conduct a climate change impact study using CMD-IHACRES and a stochastic weather generator is also
demonstrated. These results warrant further investigation into incorporating the rainfall-runoff model CMD-IHACRES
in a fully coupled 'online' approach.
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Garcia, Sade Maria. "Lattice Boltzmann Modeling and Specialized Laboratory Techniques to Determine the Permeability of Megaporous Karst Rock." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/918.
Full textAbstract:
The Pleistocene carbonate rock Biscayne Aquifer of south Florida contains laterally-extensive bioturbated ooltic zones characterized by interconnected touching-vug megapores that channelize most flow and make the aquifer extremely permeable. Standard petrophysical laboratory techniques may not be capable of accurately measuring such high permeabilities. Instead, innovative procedures that can measure high permeabilities were applied. These fragile rocks cannot easily be cored or cut to shapes convenient for conducting permeability measurements. For the laboratory measurement, a 3D epoxy-resin printed rock core was produced from computed tomography data obtained from an outcrop sample. Permeability measurements were conducted using a viscous fluid to permit easily observable head gradients (~2 cm over 1 m) simultaneously with low Reynolds number flow. For a second permeability measurement, Lattice Boltzmann Method flow simulations were computed on the 3D core renderings. Agreement between the two estimates indicates an accurate permeability was obtained that can be applied to future studies.
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Moerman, Jessica. "Regional hydrology captured in northern Borneo rainwater and dripwater isotope variability." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53523.
Full textAbstract:
Oxygen and hydrogen isotopes (δ18O, δD) are increasingly powerful tools for reconstructing past hydroclimate variability. The utility of δ18O- and δD-based paleoclimate records, however, depends on our understanding of how well these tracers reflect past climate conditions. The dynamics controlling the relationship between climate and water isotope variability are highly complex and often poorly constrained, especially in the tropics, where many key high-resolution paleoclimate records rely on past rainfall isotopes as proxies for hydroclimate. In this dissertation, I use multi-year timeseries of daily rainfall and biweekly dripwater δ18O from northern Borneo – a site for stalagmite δ18O-based paleoclimate reconstruction in the heart of the West Pacific Warm Pool – to track the cloud-to-calcite transformation of δ18O and its relationship to large-scale climate variability. Chapter 2 investigates the variability of rainfall δ18O variability from northern Borneo on diurnal to interannual timescales and its relationship with local and regional climate. Chapter 3 investigates the rainfall-to-dripwater transformation of climate-related isotopic signals following water transit through the Borneo cave system. Overall, this dissertation provides empirical support for the interpretation of northern Borneo stalagmite δ18O as a robust indicator of regional-scale hydroclimate variability, where higher δ18O reflects regional drying. More generally, this research provides a roadmap for obtaining more nuanced interpretations of speleothem δ18O records from multi-year, high-resolution, paired timeseries of rainfall and dripwater δ18O.
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Kaiser, Rachel Anne. "An Urban Karst Aquifer Resource Evaluation and Monitoring Toolbox." TopSCHOLAR®, 2019. https://digitalcommons.wku.edu/theses/3142.
Full textAbstract:
In urban karst areas, such as the City of Bowling Green, Kentucky and the Tampa Bay Metropolitan Area, groundwater quality faces a variety of threats. The development of residential, commercial, and industrial landuse types allows for a wide variety of groundwater pollutants to enter the karst groundwater systems. Various different models and indices have attempted evaluative approaches to identify issues in urban karst areas, but the methods vary by location and lack a focus on urban karst groundwater quality. There also exists a lack of a data-driven approach that is able to capture short- and long-term changes in threats to groundwater quality as a result of urbanization. The overall purpose of this study was to develop a holistic, data-driven evaluation toolbox with threat, vulnerability, and monitoring assessment tools for urban karst groundwater systems to better determine the possible threats, data collection needs, monitoring parameters, and analytical approaches needed to ensure groundwater quality is maintained in urban karst regions. This study focused on: 1) determining what indicators, parameters, resolution, and data quality need to be prioritized to create an effective, holistic monitoring framework for urban karst groundwater, and 2) developing an effective assessment and evaluative tools for urban karst groundwater quality sites using historic and modern data in an urban karst setting. The outcomes include an Urban Karst Aquifer Resource Evaluation (UKARE) Toolbox with a Threat, Vulnerability, and Monitoring evaluation tools that were applied and validated through application of the Toolbox using case studies in the City of Bowling Green, Kentucky and the Tampa Bay Metropolitan Area in Florida. The results demonstrate the universal applicability of the UKARE Toolbox to different urban karst sites and its effectiveness at scoring for threats and vulnerabilities, as well as identifying potential monitoring sites through primary data collection of water quality parameters and emerging pathogens at over 150 sites between both study areas. The final results of this study are useful to develop monitoring and management plans through a standardized scoring and evaluation tool in order to influence urban karst groundwater monitoring and management.
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au, Stefan@calm wa gov, and Stefan Eberhard. "Ecology and Hydrology of a Threatened Groundwater-Dependent Ecosystem:The Jewel Cave Karst System in Western Australia." Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20051010.141551.
Full textAbstract:
Groundwater is a significant component of the world's water balance and accounts for
>90 % of usable freshwater. Around the world groundwater is an important source of
water for major cities, towns, industries, agriculture and forestry. Groundwater plays a
role in the ecological processes and 'health' of many surface ecosystems, and is the
critical habitat for subterranean aquatic animals (stygofauna). Over-abstraction or
contamination of groundwater resources may imperil the survival of stygofauna and
other groundwater-dependent ecosystems (GDEs). In two karst areas in Western
Australia (Yanchep and Leeuwin-Naturaliste Ridge), rich stygofauna communities
occur in cave waters containing submerged tree roots. These aquatic root mat
communities were listed as critically endangered because of declining groundwater
levels, presumably caused by lower rainfall, groundwater abstraction, and/or forest
plantations. Investigation of the hydrology and ecology of the cave systems was
considered essential for the conservation and recovery of these threatened ecological
communities (TECs). This thesis investigated the hydrology and ecology of one of the
TECs, located in the Jewel Cave karst system in the Leeuwin-Naturaliste Ridge. A
multi-disciplinary approach was used to explore aspects pertinent to the hydrology and
ecology of the groundwater system.
Thermoluminescence dating of the limestone suggested that development of the karst
system dates from the Early Pleistocene and that caves have been available for
colonisation by groundwater fauna since that time. Speleogenesis of the watertable
maze caves occurred in a flank margin setting during earlier periods of wetter climate
and/or elevated base levels. Field mapping and leveling were used to determine
hydrologic relationships between caves and the boundaries of the karst aquifer.
Monitoring of groundwater levels was undertaken to characterise the conditions of
recharge, storage, flow and discharge. A hydrogeologic model of the karst system was
developed.
The groundwater hydrograph for the last 50 years was reconstructed from old
photographs and records whilst radiometric dating and leveling of stratigraphic horizons
enabled reconstruction of a history of watertable fluctuations spanning the Holocene to
Late Pleistocene. The watertable fluctuations over the previous 50 years did not exceed the range of fluctuations experienced in the Quaternary history, including a period
11,000 to 13,000 years ago when the watertable was lower than the present level.
The recent groundwater decline in Jewel Cave was not reflected in the annual rainfall
trend, which was above average during the period (1 976 to 1988) when the major drop
in water levels occurred. Groundwater abstraction and tree plantations in nearby
catchments have not contributed to the groundwater decline as previously suggested.
The period of major watertable decline coincided with a substantial reduction in fire
frequency within the karst catchment. The resultant increase in understorey vegetation
and ground litter may have contributed to a reduction in groundwater recharge, through
increased evapotranspiration and interception of rainfall. To better understand the
relationships between rainfall, vegetation and fire and their effects on groundwater
recharge, an experiment is proposed that involves a prescribed burn of the cave
catchment with before-after monitoring of rainfall, leaf-area, ground litter, soil moisture,
vadose infiltration and groundwater levels.
Molecular genetic techniques (allozyrne electrophoresis and mitochondria1 DNA) were
used to assess the species and population boundaries of two genera and species of cave
dwelling Amphipoda. Populations of both species were largely panrnictic which was
consistent with the hydrogeologic model. The molecular data supported the conclusion
that both species of amphipod have survived lower watertable levels experienced in the
caves during the Late Pleistocene. A mechanism for the colonization and isolation of
populations in caves is proposed.
Multi Dimensional Scaling was used to investigate patterns in groundwater biodiversity
including species diversity, species assemblages, habitat associations and biogeography.
Faunal patterns were related to abiotic environmental parameters. Investigation of
hydrochemistry and water quality characterized the ecological water requirements
(EWR) of the TEC and established a baseline against which to evaluate potential
impacts such as groundwater pollution.
The conservation status of the listed TEC was significantly improved by increasing the
number of known occurrences and distribution range of the community (from 10 m2 to >
2 x lo6 m2), and by showing that earlier perceived threatening processes (rainfall
decline, groundwater pumping, tree plantations) were either ameliorated or inoperative
within this catchment. The GDE in the Jewel Cave karst system may not have been
endangered by the major phase of watertable decline experienced 1975-1987, or by the
relatively stable level experienced up until 2000. However, if the present trend of
declining rainfall in southwest Wester,,Australia continues, and the cave watertable
declines > 0.5 m below the present level, then the GDE may become more vulnerable to
extinction.
The occurrence and distribution of aquatic root mat communities and related
groundwater fauna in other karst catchments in the Leeuwin-Naturaliste Ridge is
substantially greater than previously thought, however some of these are predicted to be
threatened by groundwater pumping and pollution associated with increasing urban and
rural developments. The taxonomy of most stygofauna taxa and the distribution of root
mat communities is too poorly known to enable proper assessment of their conservation
requirements. A regional-scale survey of stygofauna in southwest Western Australia is
required to address this problem. In the interim, conservation actions for the listed TECs
need to be focused at the most appropriate spatial scale, which is the karst drainage
system and catchment area. Conservation of GDEs in Western Australia will benefit
fi-om understanding and integration with abiotic groundwater system processes,
especially hydrogeologic and geomorphic processes.
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Schwartz, Benjamin Farley. "Hydrogeophysical quantification of infiltration and recharge through soil-filled sinkholes using Time Domain Reflectometry and Electrical Resistivity Tomography." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/29748.
Full textAbstract:
This dissertation presents the results of a detailed physical and hydrogeophysical study of two soil-filled sinkholes mantled by ancient New River fluvial terrace deposits. Research was performed at the Virginia Tech Kentland Experimental Farms in Whitethorne, Virginia, USA between fall 2003 and spring 2007, and focused on characterizing infiltration, deep drainage, and recharge through soil-filled sinkholes. Using hydrogeophysical methods, the spatial and temporal distribution of soil moisture was modeled and potential recharge was quantified in two soil-filled sinkholes.
Access-tube time domain reflectometry (TDR) was used to derive one-dimensional (1-D) soil moisture profiles. During access-tube installation, 470 soil samples were obtained from depths between 0.3 and to 9.0 m and characterized both physically and chemically. Using these data, a TDR calibration method was developed. Physio-chemical, TDR moisture, and 1-D electrical resistivity tomography (ERT) data were used to derive a numerically optimized form of Archieâ s Law which was used to convert ERT measurements into volumetric soil moisture. These results led to development of 2-D ERT-derived distributions of soil moisture in three transects across the two sinkholes in two terraces. Potential recharge was quantified using time-series ERT data with comparison to modeled cumulative potential evapotranspiration (PET) and cumulative precipitation between May 17 and October 9, 2006. The patterns of ERT-derived potential recharge values compared well with those expected from PET and precipitation data. Over the monitoring period from late spring to early fall during this study, results showed that a period of intense rain followed by a 31-day period of consistent rain, in which the rate of precipitation was equal to or exceeded PET, were the only periods in which significant amounts of potential recharge occurred (from 19 to 31% of cumulative precipitation during the study). Spatial distributions of ERT-derived moisture clearly revealed that significant amounts of infiltration occurred on sinkhole flanks and bottoms. Runoff during periods of intense rain flowed to the topographically lowest point in the sinkholes where it infiltrated and resulted in localized zones of enhanced infiltration and potential recharge to the water table.Ph. D.
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Groce-Wright, Nigel C. "Analyzing a 10-Year Cave Drip Record in James Cave, Virginia: Implications for Storage and Recharge in Shallow Appalachian Karst Systems." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/104202.
Full textAbstract:
Karst aquifers, characterized by soluble rocks such as limestone and dolostone, provide drinking water to 20-25% of the world's population and are thus critical global water sources. However, recent work suggests that rapid alteration of karst aquifers due to the impact of climate change on precipitation patterns may affect recharge to these aquifers.
Much of the research on recharge in karst aquifers has relied on using patterns of spring discharge to quantify recharge. Spring outlets allow for continuous monitoring of discharge from karst aquifers, making them easily accessible monitoring sites. However, because springs can integrate multiple flow paths, it is difficult to rely on spring discharge patterns to get information on where and how karst aquifers are receiving recharge. Monitoring closer to the source of recharge through the measurement of cave drips allows for a more accurate analysis of recharge timing and mechanisms.
In this study, I conducted recession analyses on cave drip hydrographs from a 10-year record (2008-2018) of three drip monitoring stations within James Cave (Pulaski Co., VA) to: 1) examine differences in hydrologic characteristics of the epikarst (the zone of soil and weathered bedrock above a karst aquifer); 2) quantify the storage volume of the epikarst and 3) investigate seasonal, and annual trends in recharge.
Results of recession analysis show heterogeneity in epikarst hydrologic characteristics, reflected by calculations of the recession coefficient, , and storage volume. Calculations of the recession coefficient show subtle differences between the three drip sites, suggestive of spatial heterogeneity in permeability and storage in the overlying epikarst. The storage volume calculations show that during the recharge season (winter- spring), up to 95% of recharge through the unsaturated zone to the cave occurs through rapid pathways (i.e., fractures), and 5% through diffuse pathways (i.e., pores). However, during the recession period (spring-summer), when evapotranspiration is active, recharge through cave drips decreases and occurs predominantly through diffuse flow. Combined, these results underscore the importance of both spatial and temporal characterization of drip rates and other recharge inputs into karst aquifer systems.Master of Science
Karst aquifers, characterized by soluble rocks such as limestone and dolostone, provide drinking water to 20-25% of the world's population and are thus critical global water sources. Recent work suggests that climate change may alter how karst aquifers are recharged; however, few studies have addressed this potential impact. This study expands knowledge of recharge in karst aquifers through analysis of a 10-year record (2008-2018) of three cave drip measuring stations in James Cave (Pulaski Co., VA). I used recession analysis of the cave drip record to investigate temporal trends in recharge and to examine hydrologic characteristics of the epikarst, the zone of soil and weathered bedrock above the cave. Results of this analysis show seasonal patterns in cave drips, with the highest drip rates occurring in the winter and early spring. The analysis also shows spatial differences in hydrologic characteristics of the epikarst. Calculations of the storage volume show during the winter and early spring, up to 95% of recharge to the cave occurs through rapid pathways (i.e., fractures), and 5% occurs through diffuse pathways (pore spaces in the soil and rock). Results of this study underscore the importance of both temporal and spatial characterization of cave drips and other recharge inputs into karst aquifer systems. The information gained from this study will add the body of knowledge on how karst aquifers receive recharge, which will aid in protection and management of these critical drinking water sources.
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Hatcher, Bruce Elliott. "Sources of CO2 Controlling the Carbonate Chemistry of the Logsdon River, Mammoth Cave, Kentucky." TopSCHOLAR®, 2013. http://digitalcommons.wku.edu/theses/1311.
Full textAbstract:
Logsdon River is a major, base-level stream within the Turnhole Bend Drainage basin of the Mammoth Cave System. The Logsdon River system has provided a unique opportunity to examine the geochemical evolution of a stream flowing through a major karst conduit that can be traversed for 10 km. This study examines CO2 inputs at the upstream portion of the river, which provide major control for the river’s hydrochemistry. Samples were collected from the upstream portion of Logsdon River at what is referred to as the S-188 sump and also nearby at Crowbar Dome over the course of 44 weeks from May 2012 through April 2013. The concentrations of CO2 for samples were calculated from field and laboratory analysis. The CO2 concentrations were examined during the study period to assess potential sources of CO2 input to the karst system in the context of seasonal variation. Seasonal fluctuations were found to be greatest in the near surface sample site, Crowbar Dome. Attenuation of seasonal variation of CO2 pressures in the upstream Logsdon River S-188 Sump suggests both surface inputs plus additional inputs of CO2 entering the system, perhaps from the decay of organic material in the saturated passages upstream beyond the accessible portion of the Logsdon River S-188 Sump. This in-cave source of CO2 has some control on hydrochemistry, and thus waterrock interaction and speleogenesis of the karst landscapes in south-central Kentucky
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Anderson, Eric Trenton. "Determining the Sustainability of Coal Mine Cavity Discharge as a Drinking Water Source." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/31709.
Full textAbstract:
In southwestern Virginia, adequate sources of public water for small isolated communities are difficult to find. While many alternatives exist, one of the largest sources of water in this region is flooded abandoned coal mines. One such coal mine aquifer was chosen for a sustainability study in Dickenson County, Virginia. A flowrate monitoring system was installed at the point of discharge from the mine, and the flow records from three months of data collection were analyzed. The recording period included one of the driest periods in recent years, and the flowrate data recorded provided useful information regarding the sustainability of the system. After a study of the geology and groundwater flow patterns in the region, it was determined that a coal mine aquifer is very similar to the extremely heterogeneous system seen in karst landscapes. Thus, techniques common to karst phenomenon were used to analyze the spring hydrograph. A spring recession analysis was performed upon five storm recessions, and the coefficients for each recession compared and discussed in light of known geologic information. It was discovered that the recession coefficients described the flow from the mine very adequately and that the mine response to a rainfall pulse was very similar to the response of certain types of karst aquifers. This information was used to predict a sustainable flow from the mine. A cross-correlation analysis was performed in an attempt to fit a "black box" model to the flow data, as well as to verify the results of the spring recession analysis. The correlation analysis proved that one rainfall event produced many separate reactions in the flowrate at the mine discharge point. This strengthened results concluded by the recession analysis. It was found that the flow record was not long enough to adequately create a statistical model, but a procedure was described that could be used to model flows once a larger flow record was available.Master of Science
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Freedman, Vicky Lynn 1963. "Erosion parameter identification in overland flow areas: Application of a global and local search algorithm." Thesis, The University of Arizona, 1996. http://hdl.handle.net/10150/278533.
Full textAbstract:
Two optimization algorithms and two objective functions were applied to determine erosion parameters for a physically-based, event-oriented model designed to simulate the processes of sedimentation for small watersheds. Three different flow-induced erosion equations were also tested with the four optimization procedures to examine the predictive capabilities of the equations. Synthetic error-free data as well as data contaminated with correlated and random error provided the means for determining the effectiveness of the four optimization procedures studied. After selecting the most effective optimization procedure and flow-induced erosion equation, the model was tested using sediment data from rainfall simulator plots and a small experimental watershed. The results from the rainfall simulator studies indicated that a structural problem may exist within the model. The agreement between simulated and observed responses for the watershed events studied indicated that the model was capable of describing sedimentation processes when they occurred on a larger scale.
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Lawhon, Nicholas. "Investigating Telogenetic Karst Aquifer Processes and Evolution in South-Central Kentucky, U.S., Using High-Resolution Storm Hydrology and Geochemistry Monitoring." TopSCHOLAR®, 2014. http://digitalcommons.wku.edu/theses/1324.
Full textAbstract:
Recent studies have investigated the hydrological and geochemical characteristics of karst aquifers in different settings; however, telogenetic karst aquifer processes remain poorly understood. In south-central Kentucky, the iconic Lost River Cave and Valley represents a large, complex telogenetic karst drainage basin with a series of discharge points along a collapsed section of the cave. Two Campbell Scientific® CR1000 automated dataloggers were installed at Blue Hole Four, a primary discharge point of the Lost River Karst Aquifer (LRKA). These dataloggers recorded spring discharge, water temperature, specific conductance (SpC), and pH at ten-minute intervals from January to November, 2013. During the year, data for 34 storm events were captured, including water samples that were analyzed for major cation/anion concentrations. These concentrations were correlated to SpC to yield a continuous record of ionic concentrations. Rainfall data were acquired from the Kentucky Mesonet’s Warren County Site within the LRKA basin. Dissolution rates, Ca2+/Mg2+ ratios, and a mass flux of dissolved CaCO3were calculated to assess aquifer evolution processes and identify seasonal and storm event variability throughout the year. A two end member mixing analysis (EMMA) is used to analyze storm flow conditions versus baseflow conditions, and a predictive model is presented that is used to predict peak springflow based upon rainfall totals. A detailed water budget analysis and comparison to historical data is used to assess groundwater storage and aquifer complexity.
The annual data reveal both seasonal and storm event patterns in geochemical and hydrologic conditions of the aquifer. The data indicate distinct responses to storm events. These responses, as well as EMMA results, indicate that storm event flows are composed initially of water formerly stored in the aquifer flushed through the aquifer by incoming meteoric water; this gradually gives way to a mixture of meteoric water and storage water that becomes gradually more similar to pre-storm conditions as discharge recedes to baseflow levels. The highest proportion of meteoric water is coincident with the highest potential for CaCO3 dissolution, indicating that storm events drive dissolution in the LRKA. Water budgeting for the full study period and individual storm events indicate that a large proportion of water in the LRKA is not discharged at Blue Hole Four, but rather is stored in the aquifer or follows another flowpath through the aquifer. Additionally, the higher rainfall totals during storm events tend to increase the proportion of water discharged from the aquifer rather than that stored within it. The predictive model indicates a strong correlation between total rainfall and peak discharge. The results overall indicate two critical times at which contaminant transport may occur: first, any contaminants stored in the aquifer will be flushed out first with storage water as discharge peaks, followed by a period in the falling limb of the discharge hydrograph that coincides with the peak proportion of meteoric water carrying contaminants that entered the aquifer during this event. This study helps to improve understanding of telogenetic karst aquifer processes and evolution, particularly in large, complex drainage basins. Future research is necessary to understand the dynamics of these important groundwater reserves and their response to continuing pressures from climate change, human impacts, and natural processes.
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Pacific, Vincent Jerald. "Hydrology and landscape structure control subalpine catchment carbon export." Thesis, Montana State University, 2009. http://etd.lib.montana.edu/etd/2009/pacific/PacificV0509.pdf.
Full textAbstract:
Carbon export from high elevation ecosystems is a critical component of the global carbon cycle. Ecosystems in northern latitudes have become the focus of much research due to their potential as large sinks of carbon in the atmosphere. However, there exists limited understanding of the controls of carbon export from complex mountain catchments due to strong spatial and temporal hydrologic variability, and large heterogeneity in landscape structure. The research presented in this dissertation investigates the control of hydrology and landscape structure and position on two major avenues of carbon loss from mountain watersheds: soil respiration and stream dissolved organic carbon (DOC) export. Measurements of soil respiration and its biophysical controls (soil water content, soil temperature, vegetation, soil organic matter, and soil physical properties) and stream and groundwater DOC dynamics are presented across three years and multiple riparian-hillslope transitions within a complex subalpine catchment in the northern Rocky Mountains, Montana. Variability in soil respiration was related to hydrologic dynamics through space and time and was strongly influenced by topography and landscape structure. Cumulative soil COâ‚‚ efflux was significantly higher from wet riparian landscape positions compared to drier hillslope locations. Changes in hydrologic regimes (e.g. snowmelt and precipitation timing and magnitude) also impacted soil respiration. From a wet to a dry growing season, there were contrasting and disproportionate changes in cumulative growing season surface COâ‚‚ efflux at wet and dry landscape positions. Stream DOC export was also influenced by landscape structure and hydrologic variability. The mobilization and delivery mechanisms of DOC from the soil to the stream were dependent upon the size of DOC source areas and the degree of hydrologic connectivity between the stream and the riparian and hillslope zones, which varied strongly across the landscape. This dissertation provides fundamental insight into the controls of hydrology and landscape structure on carbon export from complex mountain watersheds. The results of this research have large implications for the carbon source/sink status of high elevation mountain ecosystems, the influence of changing hydrologic regimes on soil respiration, and the use of landscape analysis to determine the locations of large source areas for carbon export.
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Bandy, Ashley M. "Mobility of Escherichia coli within Karst Terrains, Kentucky, USA." UKnowledge, 2016. http://uknowledge.uky.edu/ees_etds/38.
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Bacterial contamination of karst aquifers is a concern as water quality across the globe deteriorates in the face of decreasing water security. This study examined the transport and attenuation of two non-virulent isolates of Escherichia coli in relation to traditional groundwater tracers such as rhodamine WT dye and latex microspheres in two karst regions in Kentucky. Differential movement between the four tracers was observed in both epikarst and karst aquifer traces, with differences in behavior dependent on flow conditions. Attenuation was greater for the bacterial isolate containing the iha gene, compared to the isolate containing the kps gene. Microspheres of comparable size (1 µm diameter) were more easily remobilized during increases in discharge during the observed periods for both study sites. Bacteria were remobilized during storm events over 1 month after injection. Recoveries of tracers that were < 100% combined with observed remobilization during storm events illustrate the storage capacity of epikarst and karst aquifers with regard to potential contaminants.
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Barna, Joshua M. "VARIABILITY IN GROUNDWATER FLOW AND CHEMISTRY IN THE HOUZHAI KARST BASIN, GUIZHOU PROVINCE, CHINA." UKnowledge, 2019. https://uknowledge.uky.edu/ees_etds/65.
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Understanding how karst aquifers store and transmit water and contaminants is an ongoing problem in hydrogeology. Flowpath and recharge heterogeneity contribute to the complexity of these systems. This thesis explores karst-conduit connectivity and water chemistry variability in the Houzhai catchment in Guizhou province, China. Artificial tracer tests were conducted during both the monsoon and dry seasons to understand temporal variability in connectivity and water velocity between karst features. Multiple flowpaths through the catchment are activated during the monsoon season and partially abandoned during the dry season. Additionally, gradient reversals during monsoonal high-flow events and as a result of pumping can be significant. Synoptic water samples from several karst features taken during both monsoon and dry seasons elucidate spatial and temporal variability within the catchment. In general, water residence time is longer during the dry season and flow within the Houzhai catchment is temporally dependent. Time-series sampling at the outlet spring during a monsoonal storm event captured chemical variability and identified multiple flowpaths. Overall, this study refines widely applicable methods for studying karst systems to this catchment and provides a foundation for future studies in similar settings.
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Eberhard, Stefan. "Ecology and hydrology of a threatened groundwater-dependent ecosystem: the Jewel Cave karst system in Western Australia." Eberhard, Stefan (2004) Ecology and hydrology of a threatened groundwater-dependent ecosystem: the Jewel Cave karst system in Western Australia. PhD thesis, Murdoch University, 2004. http://researchrepository.murdoch.edu.au/61/.
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Groundwater is a significant component of the world's water balance and accounts for >90 % of usable freshwater. Around the world groundwater is an important source of water for major cities, towns, industries, agriculture and forestry. Groundwater plays a role in the ecological processes and 'health' of many surface ecosystems, and is the critical habitat for subterranean aquatic animals (stygofauna). Over-abstraction or contamination of groundwater resources may imperil the survival of stygofauna and other groundwater-dependent ecosystems (GDEs). In two karst areas in Western Australia (Yanchep and Leeuwin-Naturaliste Ridge), rich stygofauna communities occur in cave waters containing submerged tree roots. These aquatic root mat communities were listed as critically endangered because of declining groundwater levels, presumably caused by lower rainfall, groundwater abstraction, and/or forest plantations. Investigation of the hydrology and ecology of the cave systems was considered essential for the conservation and recovery of these threatened ecological communities (TECs). This thesis investigated the hydrology and ecology of one of the TECs, located in the Jewel Cave karst system in the Leeuwin-Naturaliste Ridge. A multi-disciplinary approach was used to explore aspects pertinent to the hydrology and ecology of the groundwater system.
Thermoluminescence dating of the limestone suggested that development of the karst system dates from the Early Pleistocene and that caves have been available for colonisation by groundwater fauna since that time. Speleogenesis of the watertable maze caves occurred in a flank margin setting during earlier periods of wetter climate and/or elevated base levels. Field mapping and leveling were used to determine hydrologic relationships between caves and the boundaries of the karst aquifer. Monitoring of groundwater levels was undertaken to characterise the conditions of recharge, storage, flow and discharge. A hydrogeologic model of the karst system was developed.
The groundwater hydrograph for the last 50 years was reconstructed from old photographs and records whilst radiometric dating and leveling of stratigraphic horizons enabled reconstruction of a history of watertable fluctuations spanning the Holocene to Late Pleistocene. The watertable fluctuations over the previous 50 years did not exceed the range of fluctuations experienced in the Quaternary history, including a period 11,000 to 13,000 years ago when the watertable was lower than the present level.
The recent groundwater decline in Jewel Cave was not reflected in the annual rainfall trend, which was above average during the period (1976 to 1988) when the major drop in water levels occurred. Groundwater abstraction and tree plantations in nearby catchments have not contributed to the groundwater decline as previously suggested. The period of major watertable decline coincided with a substantial reduction in fire frequency within the karst catchment. The resultant increase in understorey vegetation and ground litter may have contributed to a reduction in groundwater recharge, through increased evapotranspiration and interception of rainfall. To better understand the relationships between rainfall, vegetation and fire and their effects on groundwater recharge, an experiment is proposed that involves a prescribed burn of the cave catchment with before-after monitoring of rainfall, leaf-area, ground litter, soil moisture, vadose infiltration and groundwater levels.
Molecular genetic techniques (allozyrne electrophoresis and mitochondria1 DNA) were used to assess the species and population boundaries of two genera and species of cave dwelling Amphipoda. Populations of both species were largely panrnictic which was consistent with the hydrogeologic model. The molecular data supported the conclusion that both species of amphipod have survived lower watertable levels experienced in the caves during the Late Pleistocene. A mechanism for the colonization and isolation of populations in caves is proposed.
Multi Dimensional Scaling was used to investigate patterns in groundwater biodiversity including species diversity, species assemblages, habitat associations and biogeography. Faunal patterns were related to abiotic environmental parameters. Investigation of hydrochemistry and water quality characterized the ecological water requirements (EWR) of the TEC and established a baseline against which to evaluate potential impacts such as groundwater pollution.
The conservation status of the listed TEC was significantly improved by increasing the number of known occurrences and distribution range of the community (from 10 m2 to > 2 x lo6 m2), and by showing that earlier perceived threatening processes (rainfall decline, groundwater pumping, tree plantations) were either ameliorated or inoperative within this catchment. The GDE in the Jewel Cave karst system may not have been endangered by the major phase of watertable decline experienced 1975-1987, or by the relatively stable level experienced up until 2000. However, if the present trend of declining rainfall in southwest Wester,,Australia continues, and the cave watertable declines > 0.5 m below the present level, then the GDE may become more vulnerable to extinction.
The occurrence and distribution of aquatic root mat communities and related groundwater fauna in other karst catchments in the Leeuwin-Naturaliste Ridge is substantially greater than previously thought, however some of these are predicted to be threatened by groundwater pumping and pollution associated with increasing urban and rural developments. The taxonomy of most stygofauna taxa and the distribution of root mat communities is too poorly known to enable proper assessment of their conservation requirements. A regional-scale survey of stygofauna in southwest Western Australia is required to address this problem. In the interim, conservation actions for the listed TECs need to be focused at the most appropriate spatial scale, which is the karst drainage system and catchment area. Conservation of GDEs in Western Australia will benefit fi-om understanding and integration with abiotic groundwater system processes, especially hydrogeologic and geomorphic processes.
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Musgrove, MaryLynn. "Temporal links between climate and hydrology : insights from central Texas cave deposits and groundwater /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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Kipper, Chelsey. "Influence of Spring Flow Reversals on Cave Dissolution in a Telogenetic Karst Aquifer, Mammoth Cave, KY." TopSCHOLAR®, 2019. https://digitalcommons.wku.edu/theses/3158.
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An often overlooked connection between karst groundwater systems and surface water is spring flow reversal, the flow of river water into karst springs caused by changes in hydraulic gradient. Karst aquifers are subject to the intrusion of river water when the hydraulic head of a base level river is higher than the hydraulic head of a base level spring. When this occurs, the flow out of the spring reverses, allowing river water to enter base level conduits. River water thus becomes a source of recharge into karst basins, transporting both valuable nutrients and harmful contaminants into karst aquifers. The rapid recharge of meteoric water, brief groundwater residence times, and the interconnection of surface and subsurface waters through a variety of karst features necessitates studying groundwater and surface water in karst landscapes as a unified system. This study examines the influence of spring flow reversal on cave dissolution in a telogenetic karst aquifer in Mammoth Cave, Kentucky.
Spring flow reversals in Mammoth Cave National Park (MCNP) were first recorded nearly one-hundred years ago, but a high-resolution study measuring the effects of spring flow reversals on dissolution in MCNP, or any other telogenetic karst system, had not been conducted until recently. In this study, high-resolution data were collected for pH, SpC, temperature, and stage, as well as weekly samples for major ion concentrations, alkalinity, and carbon isotopes, from June 2018 to December 2018. Surface water and groundwater data were used to quantify the complex hydrologic processes associated with the spring flow reversals, including seasonal changes in karst geochemistry and dissolution taking place between the Green River, River Styx Spring, and Echo River Spring. Data show distinct changes in geochemical parameters as flow reversals occur, with temperature being the principal indicator of flow direction change. During this study, all ten stable reverse flows coincided with increased discharge from the Green River Dam. The predominant drivers of dissolution in the River Styx and Echo River karst basins are storm events and seasonal changes in the hydrologic regime, rather than seasonal CO2 production, normal baseflow conditions, or stable reverse flow events. Estimated dissolution rates generally show that stable reverse flows contribute no more to dissolution than normal baseflow conditions – the highest amount of dissolution during a single stable reverse flow was only 0.003 mm. This is contrary to flow reversal studies in an eogenetic karst system in Florida, which estimated 3.4 mm of wall retreat during a single spring flow reversal. These contrasting results are likely due to significant differences in pH of river water, matrix porosity of the bedrock, basin morphology, and flow conditions.
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Regis, Jamar. "Examining the Spatial and Temporal Variations in CO2 Partial Pressure in the Deep Vadose Zone Above Jinapsan Cave, Guam." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7904.
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Carbon dioxide is the primary driver of dissolution and precipitation reactions in epigene limestone caves. While much work has been conducted on CO2 dynamics involved in dissolution in the phreatic zone, less research has been conducted on vadose CO2 dynamics, especially in tropical caves developed in eogenetic limestones. In this study, we investigate spatial and temporal variation in pCO2 in the deep vadose zone of eogenetic limestone above Jinapsan Cave, located in northern Guam. Five years of carbonate chemistry data from three dripwater sites in Jinapsan Cave (Flatman, Station1, and Trinity) were used to model the theoretical pCO2 with which infiltrating waters had likely equilibrated along flow paths between the soil and the cave. Theoretical pCO2 essentially models the amount of CO2 that would need to be added to dripwaters that have degassed and become supersaturated with respect to calcite upon entering a lower CO2 cave void in order to return the water to equilibrium. Theoretical pCO2 values range from 10-2.8 to 10-1.8 atm among the three sites examined. These results were generally lower compared to similar studies in telogenetic and continental karst, which range from 10-3.7 to 10-0.96 atm. Theoretical pCO2 data from Jinapsan Cave have significant differences among the three drip sites, with the site closest to the entrance (Flatman) having the highest values and the farthest from the entrance (Trinity) having the lowest values; in addition, the values also have a great seasonal variability. Low theoretical pCO2 values in Jinapsan Cave’s dripwaters indicate that vadose zones in eogenetic limestone may be better ventilated, and hence have lower pCO2, than those in telogenetic limestone. The ventilation of the vadose zone is facilitated by high matrix porosity and permeability of eogenetic limestone and may be driven by barometric pressure changes or wind.
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Vaughan, Kevin. "A Quantitative Analysis of Interstitial Fluid-Chemistry and Limestone Dissolution Rates Within the Clastic Sediment of a Karst Aquifer Conduit, Mammoth Cave, Kentucky." TopSCHOLAR®, 1998. http://digitalcommons.wku.edu/theses/324.
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Many active stream conduits within karst aquifers transport and deposit non-carbonate, clastic sediment. However, little is known about how these sediments impact conduit development and enlargement rates. For example, can dissolution take place at the sediment/bedrock interface beneath a flowing stream? If not, cavern enlargement might be dominated by flood conditions when the bare rock of the walls and ceiling are in contact with the dissolving fluids. An approach using limestone tablet weight loss experiments, along with water sampling and geochemical modeling, has been undertaken to understand the nature of fluid movement and chemistry with the sediment beneath an active flowing cave stream within the Kentucky's Mammoth Cave System. Fluid flow and carbonate chemistry were compared between the active stream and within the sediment at 15, 30, 60, and 90 cm below the stream bed. It was found that carbon dioxide pressure within the interstitial fluids was elevated an order of magnitude above that of the stream waters, having levels as much as 31 times that of atmospheric background, presumably from microbial decomposition of organic material. The fluids were all under-saturated with respect to calcite (SI= -0.4 to -0.9), and limestone blocks buried at these levels all dissolved (rates from 0.8 to 21.9 g m -2 yr -1). These results suggest that at some locations the limestone bedrock may be dissolving beneath clastic sediment deposits; which in turn has implications for understanding rates and geometries of conduit evolution within karst aquifers.
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Valeo, C. "Variable source area modeling in urban areas." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0007/NQ42884.pdf.
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Booth, Bryan Charles. "An Investigation of the Effects of Chemical and Physical Weathering on Submerged Karst Surfaces." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5904.
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Reports an investigation of the effects of chemical and physical weathering on submerged karst surfaces that pairs laboratory studies with computer modeling studies. The first study attempts to quantify the production of carbonate fines; soluble sediments produced by the incomplete dissolution of karst minerals during chemical weathering. Results show carbonate fine production in relation to dissolutional action; Chalk: 42.8%; Coquina: 2.6%; Dolomite: 3.1%; Gray Limestone: 4.8%; Ocala Limestone: 3.1%; Shell Limestone: 6.1%; Travertine: 8.6%. Due to the use of hydrochloric acid as opposed to carbonic acid these results may not be fully valid for application to natural speleogenic processes. The Limestone Weathering Model, a numerical-computer model, was developed using these experimental findings as minimal values compared with published rates. Reported as the actual volume of rock mass lost to both dissolution and to carbonate fine production, the rates for carbonate fine production ranged from 5.8% to 10.9% (year 1- 5.8%, year 2- 8.5%, year 3- 9.7%, year 4-10.3%, year 5- 10.9%), with a mean value for carbonate fine production of 9%, but a continuing rate after five years approaching 11%. The second study uses metrological laser scanning to measure the erosive loss due hydraulic shearing force and corrasion on submerged limestone surfaces. The rates for material removed using increasing velocity values (0.3m/s, 0.5m/s, 1.0m/s, 1.5m/s, 2.0 m/s, 2.5m/s) during flow durations of less than 6 minutes duration were : 1) Hydraulic shearing force- 0.3µm/s, 0.5µm/s, 0.4-1.7µm/s, 2.5 µm/s, 5.5 µm/s, 2) Corrasion- 0.3 µm/s, 0.7 µm/s, 1.5 µm/s, 1.5-1.8 µm/s, 8.9 µm/s, 8.1 µm/s. The study model was modified to return these rates for hydraulic shearing force limited by the depth of the chemical corrosion of the surface. The model returns % rock volume lost to hydraulic shearing force compared to dissolutional rate (1mm/y) for 3 flow velocities (0.03m/s<, 1.0m/s<, 2.5m/s<) on 4 timing schedules: Annual 7.8,14.3,19.6, Semiannual 21.1,21.1,69.7, Quarterly- 32.8,43.6, 70.9, Monthly- 80.0, 109.3, 200.3. Model demonstrates significant effect (7.8% to 200% over dissolutional rate) on speleogenic rates from even infrequent, moderate changes in flow velocities due to storm events. Study’s results support the significance of chemical weathering by disaggregation and physical weathering by hydraulic shearing force as major factors in the processes of karst speleogenesis.
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Warren, Rachel H. Pauline. "Modifying Ohio’s DRASTIC ground water potential pollution model to account for karst limestone voids and sinkholes." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1556987810146683.
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