Fluviokarst landscapes are dominated by both fluvial and karst features. Interpreting hydrologic pathways of fluviokarst can be confounded by the unknown connectivity of the various flow regimes. A combined discrete-continuum (CDC) hybrid numeric model for simulating the surface and subsurface hydrology and hydraulics in fluviokarst basins was formulated to investigate fluviokarst pathways. This model was applied to the Cane Run Royal Springs basin in Kentucky USA. A priori constraints on parameterization were avoided via multi-stage optimization utilizing Sobol sequencing and high performance computing. Modelling results provide evidence of hydrologic pathways dominated by fracture flow, epikarst transfer and runoff. Fractures in karst basins with high fracture-matrix permeability ratios may influence both springflow and streamflow. Swallet features can be as important as spring features as they are sink features in streamflow during hydrologic events. Inflections in spring hydrographs represent shifts in the surface-subsurface connectivity via the fractures, as opposed to shifts in dominant storage zones. Existing methods of dual- and triunal hydrograph separation of karst springflow may not be directly transferrable to fluviokarst springs. The numerical model herein has advantages of suggesting dominant pathways in complex terrane and highlighting unforeseen surface-subsurface connectivity. However, disadvantages include computational expense and previous site studies.

The main aim of this thesis was to contribute with detailed information of regional environmental change during the Holocene through studies of speleothems and their growth environments from two caves, Korallgrottan and Labyrintgrottan in northwestern Sweden, and a cellar vault in Uppsala. This was done through studies of stable isotopes and luminescence properties in the speleothems in combination with a detailed monitoring study in Korallgrottan. The monitoring study suggests that stalagmites fed by stalactites with slow and stable drip rates from deep inside the cave may be suitable as palaeoclimate archives. Similarities between oxygen isotope signals of contemporary samples from Labyrintgrottan and Korallgrottan emphasize the potential of speleothems from Labyrintgrottan to also provide high resolution regional palaeoclimate information. Except for a number of cold events stalagmite δ18O records from northern Scandinavia indicate that temperatures were warmer than today between 9500 and 6000 years ago. During this period the interval between 7800 and 6000 years ago seems to have been the warmest. The area above Labyrintgrottan was most likely covered by much denser vegetation than today at the time of stalagmite growth (9500-7500 years ago) and was, unlike today, probably situated below the local tree-limit between 9000 and 8000 years ago. The δ18O record of a stalagmite from Korallgrottan covering the last 4000 years agrees with the concept of a warmer period, the so called Medieval Warm Period, centred around AD1000 and a colder period, the so called Little Ice Age, somewhere between AD1000 and today. Studies of luminescence properties in fast growing speleothems from Uppsala indicate that the variations in luminescence intensity are annual and that the annual lamiae of the luminescent record represent a flush of organic material.

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.

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

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 Archie'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.

Réduire la vulnérabilité et accroître la résilience des sociétés d'aujourd'hui aux fortes précipitations et inondations exige de mieux caractériser leur très forte variabilité spatio-temporelle observable sur une grande gamme d'échelle. Nous mettons donc en valeur tout au long de cette thèse l'intérêt méthodologique d'une approche multifractale comme étant la plus appropriée pour analyser et simuler cette variabilité. Cette thèse aborde tout d'abord le problème de la qualité des données, qui dépend étroitement de la résolution temporelle effective de la mesure, et son influence sur l'analyse multifractale et la détermination de lois d'échelle des processus de précipitations. Nous en soulignons les conséquences pour l'hydrologie opérationnelle. Nous présentons la procédure SERQUAL qui permet de quantifier cette qualité et de sélectionner les périodes correspondant aux critères de qualité requise. Un résultat surprenant est que les longues chronologies de pluie ont souvent une résolution effective horaire et rarement de 5 minutes comme annoncée. Ensuite, cette thèse se penche sur les données sélectionnées pour caractériser la structure temporelle et le comportement extrême de la pluie. Nous analysons les sources d'incertitudes dans les méthodes multifractales « classiques » d'estimation des paramètres et nous en déduisons des améliorations pour tenir compte, par exemple, de la taille finie des échantillons et des limites de la dynamique des capteurs. Ces améliorations sont utilisées pour obtenir les caractéristiques multifractales de la pluie à haute résolution de 5 minutes pour plusieurs départements de la France (à savoir, les départements 38, 78, 83 et 94) et pour aborder la question de l'évolution des précipitations durant les dernières décennies dans le cadre du changement climatique. Cette étude est confortée par l'analyse de mosaïques radars concernant trois événements majeurs en région parisienne. Enfin, cette thèse met en évidence une autre application des méthodes développées, à savoir l'hydrologie karstique. Nous discutons des caractéristiques multifractales des processus de précipitation et de débit à différentes résolutions dans deux bassins versant karstiques au sud de la France. Nous analysons, en utilisant les mesures journalière, 30 minutes et 3 minutes, la relation pluie-débit dans le cadre multifractal. Ceci est une étape majeure dans la direction d'une définition d'un modèle multi-échelle pluie-débit du fonctionnement des bassins versants karstiques / To reduce vulnerability and to increase resilience of nowadays societies to heavy precipitations and floods require better understanding of their very strong spatio-temporal variability observable over a wide range of scales. Therefore, throughout this thesis we highlight the methodological interest of a multifractal approach as being most appropriate to analyze and to simulate such the variability. This thesis first discusses the problem of data quality, which strongly depends on the effective temporal resolution of the measurements, and its influence on multifractal analysis determining the scaling laws of precipitation processes. We emphasize the consequences for operational hydrology. We present the SERQUAL procedure that allows to quantify the data quality and to select periods corresponding to the required quality criteria. A surprising result is that long chronological series of rainfall often have an effective hourly data, rather than the pretended 5-minute rainfall data. Then, this thesis focuses on the selected data to characterize the temporal structure and extreme behaviour of rainfall. We analyze the sources of uncertainties of already "classical" multifractal methods for the parameter estimates, and we therefore developed their improvements considering e.g., the finite size of data samples and the limitation of sensor dynamics. These improvements are used to obtain proper multifractal characteristics of 5-minute high-resolution rainfall for several French departments (i.e., 38, 78, 83 and 94), and hence to raise the question of preicipitation evolution during the last decades in the context of climate change. This study is reinforced by the analysis of radar mosaics for three major events in the Paris region. Finally, this thesis highlights another application of the developed methods, i.e. for the karst hydrology. We discuss the multifractal characteristics of rainfall and runoff processes observed at the different resolutions in two karst watersheds on the south of France. Using daily, 30-minute and 3-minute measurements we analyse the rainfall-runoff relationships within the multifractal framework. This is a major step towards defining a rainfall-runoff multi-scale model of the karst watershed functioning

Geomorphic features have been one of the major tools for sea-level change studies. The present work shows an example of sea-level change study on karst terrain in the tropics. Sea-level notches as well as flank margin caves were identified in the research area and their elevation measured. The time of formation of the sea-level indicators was constrained by lithology study and dating methods such as facies comparison and U-Th dating. Denudation and uplift were also studied for the same purpose. From this study it can be concluded that sea-level stands within the glacial cycle can cause the formation of flank margin caves and that the position of these sea-level stands can be determined. The research area was estimated to have cumulatively uplifted ~22 m in the past 125 ka years (~0.18 mm/yr) while the surface has been denuded some 8 m in the same span of time (~0.064 mm/yr).

English, Afrikaans and Zulu summaries / While there is increasing interest in the effect of landscape on ancient imagination, less attention has been paid to the impact of restless karst hydrology on ancient beliefs. By identifying shared themes, this study compares and contrasts the way Hittites and Aegean people in the Late Bronze and Early Iron Ages reshaped peripheral karst landscapes into physical and imagined transitional zones. Karst geology underpins much of the Aegean and Anatolian landscape, allowing subterranean zones to be visible and accessible above ground via caves, springs, sinking streams, sinkholes and other unusual natural formations. In both cultures, certain dynamic landscapes were considered to be sacred porous points where deities, daemons, heroes and mortals could transit between cosmic realms. Evidence suggests that Hittites and Aegean people interpreted dramatic karst landscapes as liminal thresholds and spaces situated between the world of humans and the world of deities. Part One investigates physical zones of transition via the karst ecosystems of rural sanctuaries. Part Two considers the creative interpretation in myth and iconography of karst phenomena into metaphysical zones of transition. The examples reveal the way in which Hittites and Aegean people built their concept of the sacred on the extraordinary characteristics of karst geology. Numinous karst landscapes provided validity and a familiar reference point for the creation of imagined worlds where mortal and divine could connect. / Vandag is daar toenemende belangstelling in die effek van die landskap op die verbeelding van die mensdom in die oudheid - maar minder aandag word bestee aan die impak van die rustelose karst landskap op die mens se gelowigheid in die oudheid. Deur die identifisering van sekere gemene temas, vergelyk hierdie verhandeling die manier waarop die Hetiete en die Egeïese volkere in die Laat Brons- en vroeë Ystertydperke die omliggende karstlandskap herskep het in fisiese en denkbeeldige oorgangszones. Die Egeïese en Anatoliese landskap bestaan grotendeels uit karst geologie, met tot gevolg dat ondergrondse zones bo die grond sigbaar en toeganklik is in die vorm van grotte, bronne, sinkgate en ander uitsonderlike natuurlike formasies. In beide bogenoemde kulture is sekere landskapstonele beskou as heilige en poreuse punte waar gode, demone, helde en sterwelinge tussen die kosmiese zones kon beweeg. Die getuienis van die tyd suggereer dat die Hetiete en die Egeïese volkere die dramatiese karst landskappe as grense of drempels tussen hulle wêreld en dié van die gode beskou het. Deel Een ondersoek die fisiese oorgangszones deur te kyk na die karst ecostelsels waarin plattelandse heiligdomme hulle bevind het. Deel Twee beskou die kreatiewe gebruik van karst verskynsels as voorstellings van metafisiese oorgangszones in die gekrewe bronne en ikonografie. Die geselekteerde voorbeelde dui aan die manier waarop die Hetiete en Egeïese volke hulle konsepte van heiligdom gebaseer het op die buitengewone verskynsels van karst geologie. Numineuse karst landskappe het hulle idees gestaaf en ‘n bekende verwysingspunt uitgemaak waar die menslike en die goddelike met mekaar in kontak kon kom. / Ngenkathi intshisekelo ekhulayo yethonya lokwakheka komhlaba emcabangweni wasendulo, kunakwe kancane umthelela we-karst hydrology engenazinkolelo ezinkolelweni zasendulo. Ngokukhomba izingqikithi okwabelwana ngazo, lo mqondo uqhathanisa futhi uqhathanise indlela amaHeti nabantu base-Aegean kweLate Bronze kanye ne-Early Iron Ages abuye abuye abumbe kabusha imigwaqo ye-karst yomngcele ibe yizingxenye zesikhashana zomzimba nezicatshangwe. I-Karst geology isekela kakhulu indawo yezwe i-Aegean ne-Anatolian evumela ukuthi izindawo ezingaphansi komhlaba zibonakale futhi zifinyeleleke ngaphezu komhlaba ngemigede, iziphethu, imifudlana ecwilayo, imigodi yokushona nokunye ukwakheka okungokwemvelo okungajwayelekile. Kuwo womabili amasiko izindawo ezithile eziguqukayo zazithathwa njengezindawo ezingcwele zokungena lapho onkulunkulu, amademoni, amaqhawe nabantu abafayo bengadlula phakathi kwezindawo zomhlaba. Ubufakazi bukhombisa ukuthi amaHeti nabantu base-Aegean bahumusha imidwebo emangazayo yekarst njengemikhawulo yemikhawulo nezikhala eziphakathi komhlaba wabantu nezwe lonkulunkulu. Ingxenye yokuqala iphenya izindawo eziguqukayo zomzimba ngokusebenzisa imvelo ye-karst yezindawo ezingcwele zasemakhaya. Ingxenye Yesibili ibheka ukutolikwa kokudala kunganekwane nakwizithonjana zezinto ze-karst kube izingxenye eziguqukayo zenguquko. Izibonelo ziveza indlela abantu abangamaHeti nabantu base- Aegean abawakha ngayo umqondo wabo ongcwele ngezimpawu ezingavamile ze-karst geology. Amathafa amahle we-karst ahlinzeka ngokusebenza kanye nephuzu elijwayelekile lesethenjwa lokwakhiwa kwamazwe acatshangelwe lapho abantu abafayo nabaphezulu bangaxhuma khona. / Biblical and Ancient Studies / M. A. (Ancient Near Eastern Studies)