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Enviroscan Ukrainian Institute of Speleology and Karstology


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Community news

Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That rising is 1. the resurgence of an underground watercourse, usually at the base margin of the calcareous massif, although in the instance of a blind valley the rising has eroded headwards for some distance. each rising accounts for the collective discharge of several sinks and in this way has a relatively high discharge as the sole drainage outlet for a large area. if the water issues freely, the rising is said to be free-flowing, but if it issues under pressure, the terms artesian, forced, or vauclusian spring are used (after the typeexample of the resurgence of the sorgue river at vaucluse in france) [19]. 2. an issue of water from massive limestone which cannot be classed with certainty as either a resurgence or a spring [20]. synonyms: (french.) emergence; (german.) ausflubtelle, karstquelle; (greek.) kephalari; (italian.) sorgente; (russian.) vyhod karstovyh vod; (spanish.) emergencia; (turkish.) yuzeye yukselis; (yugoslavian.) krsko vrelo, krski izvor, obrh. see also emergence; exsurgence; resurgence.?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms


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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
See all featured articles
Featured articles from other Geoscience Journals
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
See all featured articles from other geoscience journals

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Your search for variables (Keyword) returned 59 results for the whole karstbase:
Showing 31 to 45 of 59
The vegetation of the high mountains of Crete - a revision and multivariate analysis, 2002,
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Bergmeier E,
The vegetation at elevations above 1,400 m in the south Aegean island of Crete (Greece) is studied and revised. By means of phytosociological classification (assisted by TWINSPAN) and ordination (Detrended correspondence analysis, DCA), the plant communities and abiotic (environmental, geographical) factors governing the variance in vegetation are described and discussed. The analyses are based on 492 sample plots from the three major mountain ranges of Crete. All published data available, as well as own unpublished releves are included. Since the plots differ much with respect to species number and plot size, and to combine different subsets and different data properties, various data sets are used for DCA ordination. Data on environmental variables are used supplementarily. Ordination results suggest the following factors to be of major effect on the variance in vegetation: Rock type, soil type, altitude, geographical situation, degree of substrate fixation, and inclination. The representation of local and regional endemics in the vegetation increases with altitude and along the habitat type series: phrygana and woodland - fixed slopes - dolines - screes. A synoptic table of 26 columns (vegetation types and subtypes) is presented. The vegetation consists of the tragacanth formation of fixed slopes (8 columns), swards and scrub of doline grounds (9), scree vegetation (4), and rupicolous chasmophytic vegetation (2). Phrygana (2) and woodland vegetation (1) are marginal. A hierarchical conspectus of the syntaxa is provided which includes the following nomenclaturally relevant new or validated names of various ranks (in alphabetic order): Alysso sphaciotici-Valantion apricae, Arenario fragillimae-Silenetum antri-jovis, Arenarion creticae, Astragalion cretici, Berberido creticae-Astragaletum cretici, Cicero incisi-Silenetum variegatae, Colchico cretensis-Cirsion morinifolii, Fumano paphlagonicae-Helianthemetum hymettii, Gypsophilo nanae-Arenarietum creticae, Hyperico kelleri-Anchusetum cespitosae, Lomelosio sphacioticae-Centranthetum sieberi, Paronychio macrosepalae-Juniperetum oxycedri, Saturejo spinosae-Scutella-rietalia hirtae, Sideritido syriacae-Verbascetum spinosi, Verbascion spinosi

Could Mammoth Cave be reduced to a single equation?, 2003,
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Groves C. G. , Meiman J.

Since the evolution of any cave system is largely deterministic, in theory the processes responsible for this development could be described mathematically. In a practical sense, we will never have such a model to realistically describe the evolution of the Mammoth Cave System in detail. However, the search itself can provide a framework within which to understand what processes are important. This can guide the design of rate process studies that would eventually be coupled to provide a comprehensive understanding of the cave's evolution. Data gaps, as well, are identified during this process.
The geometry of a cave system depends on the individual growth rates of sequential sets of passage cross-sections. The growth of each of these cross-sections is determined by a set of coupled processes, the rates of which are related to well-defined variables. Major processes include limestone dissolution and precipitation (dependent on water and rock chemistry, flow characteristics, wetted passage perimeter, and temperature), sediment entrainment, deposition, and abrasion (dependent on flow velocity distributions and properties of the sediment supply), and breakdown processes (dependent on fracture characteristics). Our ability to model the complete picture depends on our grasp of these individual behaviors, as well as their interactions.
A long-term study of the behaviors of two single active passage cross-sections is underway in the Right and Left forks of Hawkins River of Mammoth Cave, where continuous water quality data are being obtained through two 145 m deep wells. Experiments are currently underway to determine storm- and seasonal-scale changes in limestone dissolution rates. Planned studies will explore sediment dynamics and the impact of sediment masking on dissolution rates, as well as potential impacts of sediment abrasion on passage growth. Complete understanding of a single cave slice is an important step to understanding cave evolution in general.


Formation of Willemite in Hydrothermal Environments, 2003,
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Brugger J, Mcphail Dc, Wallace M, Waters J,
Willemite (zinc silicate) is the main zinc mineral in some carbonate-hosted ore deposits (e.g., Franklin, New Jersey; Vazante, Brazil; Beltana, South Australia; Kabwe, Zambia). Recent interest in these unconventional zinc deposits has increased because of high zinc grades that exceed 40 wt percent, relatively low environmental impact of ore processing owing to the lack of acid-generating sulfides in the waste, and advances in ore processing technologies. In the past, most metallogenic studies proposed formation of willemite deposits by supergene or hypogene alteration of preexisting sulfide deposits. However, recent data on the Vazante, Beltana, and Kabwe deposits indicate willemite crystallization at temperatures in excess of 150{degrees}C, raising the possibility of primary precipitation from hydrothermal fluids. We use numerical geochemical modeling to examine the formation of willemite under hydrothermal conditions. Activity-activity diagrams reveal that, in the presence of dissolved sulfur and quartz, willemite instead of sphalerite will precipitate under oxidizing (e.g., hematite-stable, sulfate-predominant) and alkaline (pH higher than K feldspar-muscovite-quartz) conditions. Willemite also becomes more stable, relative to sphalerite, at high temperature, and willemite can coexist with magnetite at 300{degrees}C. The stabilities and solubilities of sphalerite, willemite, smithsonite, hydrozincite, and zincite were calculated for wide ranges of temperature (25{degrees}-300{degrees}C), chloride concentration, dissolved sulfur and carbon concentrations, pH, quartz saturation, and oxidation potential. Plots of the solubility of the different minerals as a function of two variables (e.g., temperature and redox state; pH and redox state) allow us to predict the effects of changing chemical conditions, which in turn permits an estimate of the efficiency of particular precipitation processes. Cooling is an effective process for precipitating sphalerite but not willemite, whereas pH increase (e.g., by acidic fluids reacting with carbonates) is effective for precipitating willemite but not sphalerite. Dynamic geochemical models that simulate physicochemical processes are used to understand the formation of the Beltana willemite deposit in the Adelaide geosyncline of South Australia. This small, high grade deposit (850,000 t at 36% Zn) is hosted in dolomite of the Cambrian Ajax Limestone, next to a tectonic contact with the diapiric, halite-bearing clastic sediments of the Callanna Group. The orebody is associated with hematite alteration and is characterized by the total absence of sulfides; willemite is the only zinc ore mineral, and the arsenate hedyphane (Ca2Pb3[AsO4]3Cl) is the main lead mineral. The model results show that willemite will precipitate in response to water-rock interaction and fluid mixing processes at temperatures above 120{degrees}C. The presence of arsenate in the hydrothermal fluid is likely to have been important at Beltana; in arsenate-absent models sulfate is reduced to sulfide by the precipitation of ferrous iron as hematite, resulting in the precipitation of sphalerite and galena. In contrast, in models including arsenate the reduction of sulfate to sulfide is inhibited and willemite is predicted to precipitate

Testing for reach-scale adjustments of hydraulic variables to soluble and insoluble strata: Buckeye Creek and Greenbrier River, West Virginia, 2003,
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Springer G. S. , Wohl E. E. , Foster J. A. , Boyer D. G. ,
An open question exists as to whether channel geometries and hydraulics are adjusted in bedrock streams with stable, concave profiles in a manner analogous to alluvial rivers. As a test of this problem, a comparison was undertaken of channel geometries and hydraulics among reaches with substrates that are of high mechanical resistance, but of variable chemical resistance. Reaches were selected from Buckeye Creek and Greenbrier River, West Virginia, USA because these streams flow over sandstones, limestones, and shales. The limestones have Selby rock resistance scores similar to those of the sandstones. A total of 13 reaches consisting of between 6 and 26 cross sections were surveyed in the streams. HEC-RAS was used to estimate unit stream power (omega) and shear stress (tau) for each reach. The reaches were selected to evaluate the null hypothesis that that omega and tau are equal atop soluble versus insoluble bedrock. Hypothesis tests consisted of paired t-tests and simultaneous, multiple comparisons. Geomorphic setting was included for Greenbrier River because previous studies have suggested that bedrock streams are intimately coupled with hillslopes. Holding geomorphic setting constant, three separate comparisons of omega and tau reveal that these variables are lowest atop soluble substrates in Greenbrier River (significance less than or equal to 0.05) and that changes in and tau are mediated by changes in channel geometry. Similarly, headwater reaches of Buckeye Creek developed atop shale and sandstone boulders are statistically distinguishable from downstream reaches wherein corrosion of limestone is the primary means of incision. However, comparisons in each stream reveal that channel geometries, omega and tau, are not strictly controlled by bed solubility. For constant substrate solubility along the Greenbrier River, omega and tau are consistently higher where a bedrock cutbank is present or coarse, insoluble sediment enters the channel. The latter is also associated with locally high values of omega and tau in Buckeye Creek. Assuming that incision by corrosion requires lower values of omega and tau because the channel need not be adjusted for block detachment and tool acceleration, we posit that the statistically lower values of omega and tau are tentative evidence in favor of differential geometric and hydraulic adjustments to substrate resistance. We observe that these adjustments are not made independent of geomorphic setting. (C) 2003 Elsevier Science B.V. All rights reserved

Stalagmite growth and palaeo-climate: an inverse approach, 2004,
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Kaufmann G. , Dreybrodt W. ,
The growth of stalagmites is controlled by climatic conditions such as temperature, soil activity, and precipitation. Hence, a stalagmite stratigraphy reflects fluctuations of palaeo-climate conditions on various time scales, from annual variations to ice-age cycles. However, no attempt has been made to infer palaeo-climate fluctuations from the stratigraphy itself We describe the complicated growth of a stalagmite with a simple mathematical model, in which both the growth rate and the equilibrium diameter of stalagmites are functions of palaeo-climate variables. Hence, inverting a given stalagmite stratigraphy in terms of growth rate and equilibrium diameter can in principle recover the palaeo-climate signal. The strongly nonlinear dependence of these two geometrical parameters, however, limits the success of a formal inversion of stratigraphical data. In this paper, we explore the resolving power of both growth rate and equilibrium diameter data for the palaeo-climate signals temperature, carbon-dioxide concentration, and precipitation. We use numerically generated stalagmite stratigraphies as observational data, thus we know beforehand the palaeo-climate signal contained in the stratigraphic record. Our results indicate that both variations in carbon-dioxide concentrations (as a proxy of soil cover) and drip interval (as a proxy of precipitation) can be recovered from the stratigraphy. However, temperature variations are poorly resolved. (C) 2004 Elsevier B.V. All rights reserved

Current issues and uncertainties in the measurement and modelling of air-vegetation exchange and within-plant processing of POPs, 2004,
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Barber Jl, Thomas Go, Kerstiens G, Jones Kc,
Air-vegetation exchange of POPs is an important process controlling the entry of POPs into terrestrial food chains, and may also have a significant effect on the global movement of these compounds. Many factors affect the air-vegetation transfer including: the physicochemical properties of the compounds of interest; environmental factors such as temperature, wind speed, humidity and light conditions; and plant characteristics such as functional type, leaf surface area, cuticular structure, and leaf longevity. The purpose of this review is to quantify the effects these differences might have on air/plant exchange of POPs, and to point out the major gaps in the knowledge of this subject that require further research. Uptake mechanisms are complicated, with the role of each factor in controlling partitioning, fate and behaviour process still not fully understood. Consequently, current models of air-vegetation exchange do not incorporate variability in these factors, with the exception of temperature. These models instead rely on using average values for a number of environmental factors (e.g. plant lipid content, surface area), ignoring the large variations in these values. The available models suggest that boundary layer conductance is of key importance in the uptake of POPs, although large uncertainties in the cuticular pathway prevents confirmation of this with any degree of certainty, and experimental data seems to show plant-side resistance to be important. Models are usually based on the assumption that POP uptake occurs through the lipophilic cuticle which covers aerial surfaces of plants. However, some authors have recently attached greater importance to the stomatal route of entry into the leaf for gas phase compounds. There is a need for greater mechanistic understanding of air-plant exchange and the 'scaling' of factors affecting it. The review also suggests a number of key variables that researchers should measure in their experiments to allow comparisons to be made between studies in order to improve our understanding of what causes any differences in measured data between sites. (C) 2003 Elsevier Ltd. All rights reserved

Microclimatic characterization of caves and analysis of the antropic impact for touristic use. PhD thesis , 2005,
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Ferná, Ndezcorté, S A.

The conservation and protection of caves requires suitable management tools that are based on a detailed knowledge of the environmental parameters of karst areas. The main tool for karst management is the definition and delimitation of protected areas and, in the case of tourist caves, an estimation of the visitor carrying capacity. This doctoral thesis deals with the most important methodologies related to the monitoring of cave microclimates, and focuses on show caves. The use of a great quantity of environmental data derived from different caves in southern Spain has required the use of several statistical techniques to meet the objective of simplifying and revaluating this environmental information. It is expected that the main focus of interest of this research thesis to managers of these geo-heritage sites lies in the possibility of incorporating the results of cave environmental monitoring into an integrated model of management, which also contemplates socio-economic aspects. The analysis of microclimates in each of the caves under study is dealt with in different ways depending on the type of data recorded within each one of them. Caves such as the 'Cueva del Agua' and 'Cueva de las Ventanas' are typified by the spatiotemporal behavior of the main microclimatic variables, such as the temperature and carbon dioxide content of the air. This information about the 'zero state' of the cave is complemented by an analysis of the infiltration processes and a study of the air-mass exchange phenomena. In the Sorbas karst, the design and installation of an intelligent environmental control system inside one of the potential tourist caves (System Covadura) allowed an extensive time series database to be assembled, which together with information about the spatial microclimate, comprises the base knowledge of the initial state of the cave before any tourist activities are authorized. The Giant Geode of Pulpí (Almería, Spain) represents an exceptional case with characteristics that are distinct from show caves as defined in the strictest sense of the term. The uniqueness of this site in terms of its fragility and dimension, together with the imminent need to adopt measures for its protection, resulted in the execution of an exhaustive microclimatic study in order to evaluate the possibility of opening the geode to tourists.


Microclimatic characterization of caves and analysis of the antropic impact for touristic use, PhD Thesis , 2005,
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Ferná, Ndezcorté, S A

The conservation and protection of caves requires suitable management tools that are based on a detailed knowledge of the environmental parameters of karst areas. The main tool for karst management is the definition and delimitation of protected areas and, in the case of tourist caves, an estimation of the visitor carrying capacity. This doctoral thesis deals with the most important methodologies related to the monitoring of cave microclimates, and focuses on show caves. The use of a great quantity of environmental data derived from different caves in southern Spain has required the use of several statistical techniques to meet the objective of simplifying and revaluating this environmental information. It is expected that the main focus of interest of this research thesis to managers of these geo-heritage sites lies in the possibility of incorporating the results of cave environmental monitoring into an integrated model of management, which also contemplates socio-economic aspects. The analysis of microclimates in each of the caves under study is dealt with in different ways depending on the type of data recorded within each one of them. Caves such as the 'Cueva del Agua' and 'Cueva de las Ventanas' are typified by the spatiotemporal behavior of the main microclimatic variables, such as the temperature and carbon dioxide content of the air. This information about the 'zero state' of the cave is complemented by an analysis of the infiltration processes and a study of the air-mass exchange phenomena. In the Sorbas karst, the design and installation of an intelligent environmental control system inside one of the potential tourist caves (System Covadura) allowed an extensive time series database to be assembled, which together with information about the spatial microclimate, comprises the base knowledge of the initial state of the cave before any tourist activities are authorized. The Giant Geode of Pulpí (Almería, Spain) represents an exceptional case with characteristics that are distinct from show caves as defined in the strictest sense of the term. The uniqueness of this site in terms of its fragility and dimension, together with the imminent need to adopt measures for its protection, resulted in the execution of an exhaustive microclimatic study in order to evaluate the possibility of opening the geode to tourists.


Seawater intrusion in complex geological environments, 2005,
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Abarca Cameo, Elena

Modelling seawater intrusion (SWI) has evolved from a tool for understanding to a water management need. Yet, it remains a challenge. Difficulties arise from the assessment of dispersion coefficients and the complexity of natural systems that results in complicated aquifer geometries and heterogeneity in the hydraulic parameters. Addressing such difficulties is the objective of this thesis. Specifically, factors that may affect the flow and transport in coastal aquifers and produce heterogeneous salinity distributions are studied.

First, a new paradigm for seawater intrusion is proposed since the current paradigm (the Henry problem) fails to properly reproduce observed SWI wedges. Mixing is represented by means of a velocity dependent dispersion tensor in the new proposed problem. Thereby, we denote it as "dispersive Henry problem". SWI is characterized in terms of the wedge penetration, width of the mixing zone and influx of seawater. We find that the width of the mixing zone depends basically on dispersion, with longitudinal and transverse dispersion controlling different parts of the mixing zone but displaying similar overall effects. The wedge penetration is mainly controlled by the horizontal permeability and by the geometric mean of the dispersivities. Transverse dispersivity and the geometric mean of the hydraulic conductivity are the leading parameters controlling the amount of salt that enters the aquifer.

Second, the effect of heterogeneity was studied by incorporating heterogeneity in the hydraulic permeability into the modified Henry problem. Results show that heterogeneity causes the toe to recede while increases both the width and slope of the mixing zone. The shape of the interface and the saltwater flux depends on the distribution of the permeability in each realization. However, the toe penetration and the width of the mixing zone do not show large fluctuations. Both variables are satisfactorily reproduced, in cases of moderate heterogeneity, by homogeneous media with equivalent permeability and either local or effective dispersivities.

Third, the effect of aquifer geometry in horizontally large confined aquifers was analyzed. Lateral slope turned out to be a critical factor. Lateral slopes in the seaside boundary of more than 3% cause the development of horizontal convection cells. The deepest zones act as preferential zones for seawater to enter the aquifer and preferential discharging zones are developed in the upwards lateral margins. A dimensionless number, Nby, has been defined to estimate the relative importance of this effect.

All these factors can be determinant to explain the evolution of salinity in aquifers such as the Main aquifer of the Llobregat delta. Finally, a management model of this aquifer is developed to optimally design corrective measures to restore the water quality of the aquifer. The application of two different optimization methodologies, a linear and a non-linear optimization method, allowed (1) to quantify the hydraulic efficiency of two potential corrective measures: two recharge ponds and a seawater intrusion barrier; (2) to determine the water necessary to be injected in each of these measures to restore the water quality of the aquifer while minimizing changes in the pumping regime and (3) to assess the sustainable pumping regime (with and without the implementation of additional measures) once the water quality has been restored. Shadow prices obtained from linear programming become a valuable tool to quantify the hydraulic efficiency of potential corrective measures to restore water quality in the aquifer


Incorporation of Auxiliary Information in the Geostatistical Simulation of Soil Nitrate Nitrogen, 2006,
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Grunwald S. , Goovaerts P. , Bliss C. M. , Comerford N. B. , Lamsal S. ,
In north-central Florida the potential risk for movement of nitrate into the aquifer is high due to the large extent of well-drained marine-derived quartz sand overlying porous limestone material coupled with high precipitation rates. Our objective was to estimate spatio-seasonal distributions of soil NO3-N across the Santa Fe River Watershed in north-central Florida. We conducted spatially distributed synoptic and seasonal sampling (September 2003--wet summer/fall season, January 2004--dry winter season, May 2004--dry spring season) of soil NO3-N. Prior distributions of probability for NO3-N were inferred at each location across the watershed using ordered logistic regression. Explanatory variables included environmental spatial datasets such as land use, drainage class, and the Floridian aquifer DRASTIC index. These prior probabilities were then updated using indicator kriging, and multiple realizations of the spatial distribution of soil NO3-N were generated by sequential indicator simulation. Cross-validation indicated that smaller prediction errors are obtained when secondary information is incorporated in the analysis and when indicator kriging is used instead of ordinary kriging to analyze these datasets characterized by the presence of extreme high values and a nonnegligible number of data below the detection limit. The NO3-N values were lowest in September 2003 as a result of excessive leaching caused by large, intense tropical storms. Overall the NO3-N values in January 2004 were high and could be attributed to fertilization of crops and pastures, low plant uptake, and low microbial transformation during the winter period. Despite seasonal trends reflected by the values of observed and estimated NO3-N, we found areas that showed consistently high soil NO3-N throughout all seasons. Those areas are prime targets to implement best management practices

Seasonal Variations in Modern Speleothem Calcite Growth in Central Texas, U.S.A, 2007,
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Banner Jl, Guilfoyle A, James Ew, Stern La, Musgrove M,
Variations in growth rates of speleothem calcite have been hypothesized to reflect changes in a range of paleoenvironmental variables, including atmospheric temperature and precipitation, drip-water composition, and the rate of soil CO2 delivery to the subsurface. To test these hypotheses, we quantified growth rates of modern speleothem calcite on artificial substrates and monitored concurrent environmental conditions in three caves across the Edwards Plateau in central Texas. Within each of two caves, different drip sites exhibit similar annual cycles in calcite growth rates, even though there are large differences between the mean growth rates at the sites. The growth-rate cycles inversely correlate to seasonal changes in regional air temperature outside the caves, with near-zero growth rates during the warmest summer months, and peak growth rates in fall through spring. Drip sites from caves 130 km apart exhibit similar temporal patterns in calcite growth rate, indicating a controlling mechanism on at least this distance. The seasonal variations in calcite growth rate can be accounted for by a primary control by regional temperature effects on ventilation of cave-air CO2 concentrations and/or drip-water CO2 contents. In contrast, site-to-site differences in the magnitude of calcite growth rates within an individual cave appear to be controlled principally by differences in drip rate. A secondary control by drip rate on the growth rate temporal variations is suggested by interannual variations. No calcite growth was observed in the third cave, which has relatively high values of and small seasonal changes in cave-air CO2. These results indicate that growth-rate variations in ancient speleothems may serve as a paleoenvironmental proxy with seasonal resolution. By applying this approach of monitoring the modern system, speleothem growth rate and geochemical proxies for paleoenvironmental change may be evaluated and calibrated

Validation of vulnerability mapping methods by field investigations and numerical modelling, 2008,
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Neukum Christoph, Hotzl Heinz, Himmelsbach Thomas

Vulnerability maps illustrate the potential threat of contaminants to groundwater and can be considered as important tools for land-use planning and related legislation. For karst areas with characteristic preferential infiltration conditions, vulnerability maps are also excellent tools for source and resource protection. However, the resulting qualitative maps are often inconsistent and even contradictive and thus might lead to inconclusive vulnerability assessments. The results of a validation of vulnerability maps produced using four different methods, DRASTIC, GLA, PI and EPIK, are reported for a karst area in southwest Germany. By means of measured hydraulic and transport parameters of the geological sequence, numerical simulations were used based on a conceptual model for the area under study. The mean transit time through the unsaturated zone (resource protection) was used as the validation parameter. The study demonstrates that the highest level of accuracy is achieved with the GLA- and PI methods. Both DRASTIC and EPIK are not able to incorporate highly variable distributions and thickness of cover sediments and their protective properties in the respective mapping procedure. Thus, vulnerability maps produced with DRASTIC, EPIK, and related methods should be used with care when employed in vulnerability assessments for land use planning and related decision-making.
Les cartes de vulnerabilite illustrent la menace potentielle des contaminants envers les eaux souterraines, et peuvent etre considerees comme des outils importants en matiere d'amenagement foncier et de reglementation associee. Sur les domaines karstiques, caracterises par des conditions d'infiltration preferentielle, ces cartes sont egalement d'excellents outils de protection des sources et des ressources. Cependant, les cartes qualitatives resultantes sont generalement incoherentes voire contradictoires, et peuvent par la-meme mener a des evaluations de vulnerabilite peu concluantes. La presente etude expose les resultats de validation de cartes de vulnerabilite produites selon quatre methodes differentes (DRASTIC, GLA, PI et EPIK), dans le cas d'un domaine karstique du sud-est de l'Allemagne. Par le biais des parametres de transport et hydrauliques mesures sur la sequence geologique, des simulations numeriques basees sur un modele conceptuel du secteur d'etude ont ete utilisees. Les temps de transit moyens a travers la zone non saturee (protection de la ressource) ont ete utilises comme parametres de validation. L'etude demontre que le niveau maximum de precision est obtenu par les methodes GLA et PI. Dans la phase de cartographie, les methodes EPIK et DRASTIC sont incapables d'integrer une forte variabilite dans les distributions et les epaisseurs de sediments de couverture, ainsi que dans leurs potentiels de protection. Aussi, les cartes de vulnerabilite produites par les methodes DRASTIC et EPIK doivent etre utilisees avec precaution dans le cadre des evaluations de vulnerabilite a but decisionnaire pour les amenagements fonciers.
Los mapas de vulnerabilidad ilustran la amenaza potencial de contaminantes para el agua subterranea y pueden ser considerados herramientas importantes para planeamiento del uso de la tierra y legislacion relacionada. Para areas carsticas con sus caracteristicas condiciones de infiltracion preferencial, los mapas de vulnerabilidad son tambien excelentes herramientas para proteccion de fuentes y recursos. Sin embargo, los mapas cualitativos resultantes son frecuentemente inconsistentes y hasta contradictorios y por lo tanto podrian conducir a evaluaciones de vulnerabilidad no concluyentes. Los resultados de una validacion de mapas de vulnerabilidad producidos usando cuatro metodos diferentes, DRASTIC, GLA, PI y EPIK, son presentados aqui para un area carstica en Alemania suroccidental. Se usaron simulaciones numericas usando parametros hidraulicos y de transporte medidos de la secuencia geologica y basandose en un modelo conceptual del area en estudio. El tiempo promedio de transito a traves de la zona no saturada (proteccion del recurso) fue utilizado como el parametro de validacion. El estudio demuestra que el maximo nivel de precision es alcanzado con los metodos GLA y PI. DRASTIC y EPIK no fueron capaces de incorporar distribuciones altamente variables ni espesor de sedimentos de cubierta y sus propiedades protectivas en el respectivo procedimiento de elaboracion de mapas. Por lo tanto los mapas de vulnerabilidad producidos con DRASTIC, EPIK y metodos relacionados deberian ser usados con cuidado cuando se usen en evaluaciones de vulnerabilidad para planeamiento del uso de tierra


Improving sinkhole hazard models incorporating magnitudefrequency relationships and nearest neighbor analysis, 2011,
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Galve Jorge P. , Remondo Juan, Gutié, Rrez Francisco

This work presents a methodology for elaborating sinkhole hazard models that incorporate the magnitude and frequency relationships of the subsidence process. The proposed approach has been tested in a sector of the Ebro valley mantled evaporite karst, where sinkholes, largely induced by irrigation practices, have a very high occurrence rate (>50 sinkholes/km2/yr). In this area, covering 10 km2, a total of 943 new cover collapse sinkholes were inventoried in 2005 and 2006. Multiple susceptibility models have been generated analyzing the statistical relationships between the 2005 sinkholes and different sets of variables, including the nearest sinkhole distance. The quantitative evaluation of the prediction capability of these models using the 2006 sinkhole population has allowed the identification of the method and variables that produce the most reliable predictions. The incorporation of the indirect variable nearest sinkhole distance has contributed significantly to increase the quality of the models, despite simplifying the modeling process by using categorical rather than continuous variables. The best susceptibility model, generated with the total sinkhole population and the selected method and variables, has been transformed into a hazard model that provides minimum estimates of the spatial–temporal probability of each pixel to be affected by sinkholes of different diameter ranges. This transformation has been carried out combining two equations derived from the more complete 2006 sinkhole population; one of them expressing the expected spatial–temporal probability of sinkhole occurrence and the other the empirical magnitude and frequency relationships generated for two different types of land surfaces, which control the strength of the surface layer and the size of the sinkholes. The presented method could be applied to predict the spatial–temporal probability of events with different magnitudes related to other geomorphic processes (e.g. landslides).


Clastic Sediments in Caves, 2012,
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Springer, Gregory S.

This article focuses on the natures, origins, and significances of clastic sediments in caves. Clastic sediments are fragments of preexisting rocks that have been transported and redeposited. Streams transport large quantities of clastic sediments through caves, including stream gravels and mud, but clastic sediments also move as gravity flows by slumping and sliding. Sedimentology and stratigraphy offer the means to understand the origins and transport mechanisms behind individual clastic deposits. Together, the two methodologies consider layering within deposits and grain sizes, sorting, mineralogies, and sedimentary structures within individual beds. Facies are recognized where those variables include diagnostic properties tied to particular depositional processes or driving forces. As is shown using examples, stratigraphy and facies analysis make it possible to reconstruct cave or landscape histories, including system responses to disturbances such as climate change and land use. Notably, system responses typically reflect changes in sediment supply, hydraulic gradients, or obstructions. These factors are recorded in passage morphologies, which should always be considered when studying clastic sediments in caves, and examples are cited.


Cave Cricket Exit Counts: Environmental Influences and Duration Surveys, 2012,
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Wekerly, F. W.

 

Cave cricket abundance is used as an indicator of integrity of cave ecosystems. One means of monitoring cave cricket abundance is counting crickets as they emerge from cave entrances for two hours after sunset. The influence of cloud cover, relative humidity, and surface temperature on counts is unknown and there might be few cave crickets that emerge during the first hour of the survey. Using mixed effects models, I assessed the influence of these environmental variables on exit counts and estimated when cave crickets emerged within the two-hour survey period. Exit-count surveys were conducted in eleven caves over four years in central Texas, and caves were surveyed up to four times a year across the four calendar seasons. Cloud cover, relative humidity, and temperature influenced counts, but the greatest influence was from temperature. Peaks in cave cricket counts occurred 80 to 90 minutes after the start of a survey and declined thereafter. Cave cricket exit count surveys should record surface temperature, cloud cover, and relative humidity at the start of surveys so that counts can be adjusted for these environmental influences. Also, surveys can be shortened to 1 or 1.5 hours in length. Cave cricket abundance is used as an indicator of integrity of cave ecosystems. One means of monitoring cave cricket abundance is counting crickets as they emerge from cave entrances for two hours after sunset. The influence of cloud cover, relative humidity, and surface temperature on counts is unknown and there might be few cave crickets that emerge during the first hour of the survey. Using mixed effects models, I assessed the influence of these environmental variables on exit counts and estimated when cave crickets emerged within the two-hour survey period. Exit-count surveys were conducted in eleven caves over four years in central Texas, and caves were surveyed up to four times a year across the four calendar seasons. Cloud cover, relative humidity, and temperature influenced counts, but the greatest influence was from temperature. Peaks in cave cricket counts occurred 80 to 90 minutes after the start of a survey and declined thereafter. Cave cricket exit count surveys should record surface temperature, cloud cover, and relative humidity at the start of surveys so that counts can be adjusted for these environmental influences. Also, surveys can be shortened to 1 or 1.5 hours in length.


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