WorldWideScience

Sample records for survey karst interest

  1. U.S. Geological Survey Karst Interest Group Proceedings, Bowling Green, Kentucky, May 27-29, 2008

    Science.gov (United States)

    Kuniansky, Eve L.

    2008-01-01

    States are developed in carbonate rocks and karst areas. These aquifers and the springs that discharge from them, serve as major water-supply sources and as unique biological habitats. Commonly, there is competition for the water resources of karst aquifers, and urban development in karst areas can impact the ecosystem and water quality of these aquifers. The concept for developing a Karst Interest Group evolved from the November 1999 National Ground-Water Meeting of the U.S. Geological Survey (USGS), Water Resources Division. As a result, the Karst Interest Group was formed in 2000. The Karst Interest Group is a loose-knit grass-roots organization of USGS employees devoted to fostering better communication among scientists working on, or interested in, karst hydrology studies. The mission of the Karst Interest Group is to encourage and support interdisciplinary collaboration and technology transfer among USGS scientists working in karst areas. Additionally, the Karst Interest Group encourages cooperative studies between the different disciplines of the USGS and other Department of Interior agencies and university researchers or research institutes. The first Karst Interest Group workshop was held in St. Petersburg, Florida, February 13-16, 2001, in the vicinity of karst features of the Floridan aquifer system. The proceedings of that first meeting, Water-Resources Investigations Report 01-4011 are available online at: http://water.usgs.gov/ogw/karst/ The second Karst Interest Group workshop was held August 20-22, 2002, in Shepherdstown, West Virginia, in close proximity to the carbonate aquifers of the northern Shenandoah Valley. The proceedings of the second workshop were published in Water-Resources Investigations Report 02-4174, which is available online at the previously mentioned website. The third workshop of the Karst Interest Group was held September, 12-15, 2005, in Rapid City, South Dakota, which is in close proximity to karst features

  2. U.S. Geological Survey Karst Interest Group Proceedings, Carlsbad, New Mexico, April 29-May 2, 2014

    Science.gov (United States)

    Kuniansky, Eve L.; Spangler, Lawrence E.; Kuniansky, Eve L.; Spangler, Lawrence E.

    2014-01-01

    strong interest in the study of karst terrains.Many of the major springs and aquifers in the United States have developed in carbonate rocks, such as the Floridan aquifer system in Florida and parts of Alabama, Georgia, and South Carolina; the Ozark Plateaus aquifer system in parts of Arkansas, Kansas, Missouri, and Oklahoma; and the Edwards-Trinity aquifer system in west-central Texas. These aquifers, and the springs that discharge from them, serve as major water-supply sources and as unique ecological habitats. Competition for the water resources of karst aquifers is common, and urban development and the lack of attenuation of contaminants in karst areas can impact the ecosystem and water quality of these aquifers.The concept for developing a platform for interaction among scientists within the U.S. Geological Survey (USGS) working on karst-related studies evolved from the November 1999 National Ground-Water Meeting of the USGS. As a result, the Karst Interest Group (KIG) was formed in 2000. The KIG is a loose-knit, grass-roots organization of USGS and non-USGS scientists and researchers devoted to fostering better communication among scientists working on, or interested in, karst science. The primary mission of the KIG is to encourage and support interdisciplinary collaboration and technology transfer among scientists working in karst areas. Additionally, the KIG encourages collaborative studies between the different mission areas of the USGS as well as other federal and state agencies, and with researchers from academia and institutes. The KIG also encourages younger scientists by participation of students in the poster and oral sessions.To accomplish its mission, the KIG has organized a series of workshops that are held near nationally important karst areas. To date (2014) six KIG workshops, including the workshop documented in this report, have been held. The workshops typically include oral and poster sessions on selected karst-related topics and research, as well

  3. U.S. Geological Survey Karst Interest Group Proceedings, San Antonio, Texas, May 16–18, 2017

    Science.gov (United States)

    Kuniansky, Eve L.; Spangler, Lawrence E.

    2017-05-15

    karst hydrogeologic systems. As a result, numerous federal, state, and local agencies have a strong interest in the study of karst terrains.Many of the major springs and aquifers in the United States have developed in carbonate rocks, such as the Floridan aquifer system in Florida and parts of Alabama, Georgia, and South Carolina; the Ozark Plateaus aquifer system in parts of Arkansas, Kansas, Missouri, and Oklahoma; and the Edwards-Trinity aquifer system in west-central Texas. These aquifers, and the springs that discharge from them, serve as major water-supply sources and form unique ecological habitats. Competition for the water resources of karst aquifers is common, and urban development and the lack of attenuation of contaminants in karst areas due to dissolution features that form direct pathways into karst aquifers can impact the ecosystem and water quality associated with these aquifers.The concept for developing a platform for interaction among scientists within the U.S. Geological Survey (USGS) working on karst-related studies evolved from the November 1999 National Groundwater Meeting of the USGS. As a result, the Karst Interest Group (KIG) was formed in 2000. The KIG is a loose-knit, grass-roots organization of USGS and non-USGS scientists and researchers devoted to fostering better communication among scientists working on, or interested in, karst science. The primary mission of the KIG is to encourage and support interdisciplinary collaboration and technology transfer among scientists working in karst areas. Additionally, the KIG encourages collaborative studies between the different mission areas of the USGS as well as with other federal and state agencies, and with researchers from academia and institutes.To accomplish its mission, the KIG has organized a series of workshops that have been held near nationally important karst areas. To date (2017) seven KIG workshops, including the workshop documented in this report, have been held. The workshops

  4. Submerged karst landforms observed by multibeam bathymetric survey in Nagura Bay, Ishigaki Island, southwestern Japan

    Science.gov (United States)

    Kan, Hironobu; Urata, Kensaku; Nagao, Masayuki; Hori, Nobuyuki; Fujita, Kazuhiko; Yokoyama, Yusuke; Nakashima, Yosuke; Ohashi, Tomoya; Goto, Kazuhisa; Suzuki, Atsushi

    2015-01-01

    Submerged tropical karst features were discovered in Nagura Bay on Ishigaki Island in the southern Ryukyu Islands, Japan. The coastal seafloor at depths shallower than ~ 130 m has been subjected to repeated and alternating subaerial erosion and sedimentation during periods of Quaternary sea-level lowstands. We conducted a broadband multibeam survey in the central area of Nagura Bay (1.85 × 2.7 km) and visualized the high-resolution bathymetric results over a depth range of 1.6-58.5 m. Various types of humid tropical karst landforms were found to coexist within the bay, including fluviokarst, doline karst, cockpit karst, polygonal karst, uvalas, and mega-dolines. Although these submerged karst landforms are covered by thick postglacial reef and reef sediments, their shapes and sizes are distinct from those associated with coral reef geomorphology. The submerged landscape of Nagura Bay likely formed during multiple glacial and interglacial periods. According to our bathymetric results and the aerial photographs of the coastal area, this submerged karst landscape appears to have developed throughout Nagura Bay (i.e., over an area of approximately 6 × 5 km) and represents the largest submerged karst in Japan.

  5. Submarine Salt Karst Terrains

    Directory of Open Access Journals (Sweden)

    Nico Augustin

    2016-06-01

    Full Text Available Karst terrains that develop in bodies of rock salt (taken as mainly of halite, NaCl are special not only for developing in one of the most soluble of all rocks, but also for developing in one of the weakest rocks. Salt is so weak that many surface-piercing salt diapirs extrude slow fountains of salt that that gravity spread downslope over deserts on land and over sea floors. Salt fountains in the deserts of Iran are usually so dry that they flow at only a few cm/yr but the few rain storms a decade so soak and weaken them that they surge at dm/day for a few days. We illustrate the only case where the rates at which different parts of one of the many tens of subaerial salt karst terrains in Iran flows downslope constrains the rates at which its subaerial salt karst terrains form. Normal seawater is only 10% saturated in NaCl. It should therefore be sufficiently aggressive to erode karst terrains into exposures of salt on the thousands of known submarine salt extrusions that have flowed or are still flowing over the floors of hundreds of submarine basins worldwide. However, we know of no attempt to constrain the processes that form submarine salt karst terrains on any of these of submarine salt extrusions. As on land, many potential submarine karst terrains are cloaked by clastic and pelagic sediments that are often hundreds of m thick. Nevertheless, detailed geophysical and bathymetric surveys have already mapped likely submarine salt karst terrains in at least the Gulf of Mexico, and the Red Sea. New images of these two areas are offered as clear evidence of submarine salt dissolution due to sinking or rising aggressive fluids. We suggest that repeated 3D surveys of distinctive features (± fixed seismic reflectors of such terrains could measure any downslope salt flow and thus offer an exceptional opportunity to constrain the rates at which submarine salt karst terrains develop. Such rates are of interest to all salt tectonicians and the many

  6. Submerged Humid Tropical Karst Landforms Observed By High-Resolution Multibeam Survey in Nagura Bay, Ishigaki Island, Southwestern Japan

    Science.gov (United States)

    Kan, H.; Urata, K.; Nagao, M.; Hori, N.; Fujita, K.; Yokoyama, Y.; Nakashima, Y.; Ohashi, T.; Goto, K.; Suzuki, A.

    2014-12-01

    Submerged tropical karst features were discovered in Nagura Bay on Ishigaki Island in the South Ryukyu Islands, Japan. This is the first description of submerged humid tropical karst using multibeam bathymetry. We conducted a broadband multibeam survey in the central area of Nagura Bay (1.85 × 2.7 km) and visualized the high-resolution bathymetric results with a grid size of 1 m over a depth range of 1.6-58.5 m. Various types of humid tropical karst landforms were found to coexist within the bay, including fluviokarst, doline karst, cockpit karst, polygonal karst, uvalas, and mega-dolines. We assume that Nagura Bay was a large karst basin in which older limestone remained submerged, thus preventing corrosion and the accumulation of reef sediments during periods of submersion, whereas the limestone outcropping on land was corroded during multiple interglacial and glacial periods. Based on our bathymetric result together with aerial photographs of the coastal area, we conclude that the submerged karst landscape has likely developed throughout the whole of Nagura Bay, covering an area of ~6 × 5 km. Accordingly, this area hosts the largest submerged karst in Japan. We also observed abundant coral communities during our SCUBA observations. The present marine conditions of Nagura Bay are characterized by low energy (calm sea) and low irradiance owing to the terrestrial influence. Such conditions have been emphasized by the presence of large undulating landforms, which cause decreases in wave intensity and irradiance with depth. These characteristics have acted to establish unique conditions compared to other coral reef areas in the Ryukyu Islands. It may play an important role in supporting the regional coral reef ecosystem.

  7. Regional-scale airborne electromagnetic surveying of the Yucatan karst aquifer (Mexico): geological and hydrogeological interpretation

    DEFF Research Database (Denmark)

    Gondwe, Bibi Ruth Neuman; Ottowitz, David; Supper, Robert

    2012-01-01

    -spectral remote sensing imagery, shuttle radar topography data and frequency-domain airborne electromagnetic (AEM) survey data were used to map karst-aquifer structure on the Yucatan Peninsula, Mexico. Anomalous AEM responses correlated with topographic features and anomalous spectral reflectance of the terrain...... as ejecta from the Chicxulub impact (Cretaceous/Paleogene boundary), based on similar resistivity signatures found in borehole logs. Due to limited sensitivity of the AEM survey, the subsurface configuration beneath the low-resistivity layer could not be unambiguously determined. AEM measurements combined...

  8. [Research interest by general practitioners: a survey].

    Science.gov (United States)

    Rossi, S; Zoller, M; Steurer, J

    2006-12-06

    For doing research on topics in primary care medicine participation of primary care physicians is necessary. Research in this field of medicine is only marginally established in Switzerland. In a postal survey we evaluate the general attitudes of physicians towards research in the field of primary care. In particular we were interested in their willingness to participate in research projects and the facilitating and impeding factors to take part in such projects. A purpose designed questionnaire was sent by post to 3044 primary care physicians in the central and eastern parts of Switzerland. The return rate was 52%. A majority of 94% of the responding physicians revealed interest in primary care research and 60% of all responders are willing to participate actively in such projects. They are prepared to spend about 15 min a day for data acquisition. Their willingness to participate depends on the conditions that, first, the research topic is relevant for daily practice and, second, boards odder Continuous Medical Education credits for time spent for research. Time constraints, additional administrative work and lack of relevance of research topics to daily practice are the main barriers. This survey demonstrates the general interest of primary care physicians to participate in relevant research projects. Therefore the structure to set up such research should be established.

  9. 12 CFR 906.5 - Monthly interest rate survey.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Monthly interest rate survey. 906.5 Section 906... OPERATIONS OPERATIONS Monthly Interest Rate Survey (MIRS) § 906.5 Monthly interest rate survey. The Finance... Board and is used for determining the movement of the interest rate on renegotiable-rate mortgages and...

  10. Karst Feature Inventory Points

    Data.gov (United States)

    Minnesota Department of Natural Resources — Southeastern Minnesota is part of the Upper Mississippi Valley Karst (Hedges and Alexander, 1985) that includes southwestern Wisconsin and northeastern Iowa. Karst...

  11. Tracer techniques in karst hydrogeology. Application to the location of karst aquifers

    International Nuclear Information System (INIS)

    Mangin, A.; Molinari, J.

    1976-01-01

    From the recent progress in karst aquifer simulation techniques and the improved knowledge of tracers, the old-established tracer technique has become an invaluable instrument for hydrogeological survey work. Typical information obtainable includes karst system boundaries features and location of hydrodynamic discontinuities, flow variation in both space and time. Tracer methods are a basic requirement for investigation of karst groundwater supplies and determining protection zones for water supply points [fr

  12. Pupil interest in physics: A survey in Finland

    Directory of Open Access Journals (Sweden)

    Jari Lavonen

    2005-11-01

    Full Text Available Factors interrelating with interest in physics learning are gender, perceived relevance, contents and contexts of physics, and teaching methods. Finnish ninth grade secondary school pupil interest in physics in different contexts was investigated with a survey conducted in connection with the international ROSE project. The sample consisted of 3626 pupils (median age 15 in 61 schools. Means of all items that belong to school physics context for both girls and boys were under the middle of the scale. The most interesting things (especially for girls were connected with human being and the less interesting (especially for girls were connected in artefacts and technological processes. Astronomical context was rather interesting for both genders. The main message of the study is that interesting new curricular approaches and textbooks can be developed by combining technological and human or astronomical contexts.

  13. A new species of karst forest Bent-toed Gecko (genus Cyrtodactylus Gray) not yet threatened by foreign cement companies and a summary of Peninsular Malaysia's endemic karst forest herpetofauna and the need for its conservation.

    Science.gov (United States)

    Grismer, L Lee; Wood, P L Jr; Anuar, Shahrul; Davis, H R; Cobos, A J; Murdoch, M L

    2016-01-04

    A new species of Bent-toed Gecko, Cyrtodactylus gunungsenyumensis sp. nov. of the sworderi complex, is described from Hutan Lipur Gunung Senyum, Pahang, Peninsular Malaysia and is differentiated from all other species in the sworderi complex by having a unique combination of characters including a maximum SVL of 74.7 mm; low, rounded, weakly keeled, body tubercles; 34-40 paravertebral tubercles; weak ventrolateral body fold lacking tubercles; 38-41 ventral scales; an abrupt transition between the posterior and ventral femoral scales; 20-23 subdigital lamellae on the fourth toe; enlarged femoral scales; no femoral or precloacal pores; no precloacal groove; wide caudal bands; and an evenly banded dorsal pattern. Cyrtodactylus gunungsenyumensis sp. nov. is a scansorial, karst forest-adapted specialist endemic to the karst ecosystem surrounding Gunung Senyum and occurs on the vertical walls of the limestone towers as well as the branches, trunks, and leaves of the vegetation in the associated karst forest. Cyrtodactylus gunungsenyumensis sp. nov. is the seventh species of karst forest-adapted Cyrtodactylus and the sixteenth endemic species of karst ecosystem reptile discovered in Peninsular Malaysia in the last seven years from only 12 different karst forests. This is a clear indication that many species remain to be discovered in the approximately 558 isolated karst ecosystems in Peninsular Malaysia not yet surveyed. These data continue to underscore the importance of karst ecosystems as reservoirs of biodiversity and microendemism and that they constitute an important component of Peninsular Malaysia's natural heritage and should be protected from the quarrying interests of foreign industrial companies.

  14. Karst in Slovenia; EL karst en Eslovenia

    Energy Technology Data Exchange (ETDEWEB)

    Mihevc, A.; Gabrovsek, F.; Knez, M.; Kozel, P.; Mulec, J.; Otomicar, B.; Petric, M.; Pipan, T.; Prelovsek, M.; Slabe, T.; Sebela, S.; Zupan Hajna, N.

    2016-07-01

    Karst is a type of landscape with special surface, underground and hydrological features and phenomena. Its main characteristic is dissolution of the carbonate rocks by water enriched with CO{sub 2} as the dominant morphological process, removal of the rock in the form of solution and prevalent underground drainage that forms caves. In Slovene language, kras means a rocky, barren surface developed on limestone or dolomite and is also used as a toponym, so the word karst was developed from the name of the Kras plateau, which is a classical, reference site for the karst type of landscape. (Author)

  15. Evaporite karst geohazards in the Delaware Basin, Texas: review of traditional karst studies coupled with geophysical and remote sensing characterization

    Directory of Open Access Journals (Sweden)

    Kevin W. Stafford

    2017-06-01

    Full Text Available Evaporite karst throughout the Gypsum Plain of west Texas is complex and extensive, including manifestations ranging from intrastratal brecciation and hypogene caves to epigene features and suffosion caves. Recent advances in hydrocarbon exploration and extraction has resulted in increased infrastructure development and utilization in the area; as a result, delineation and characterization of potential karst geohazards throughout the region have become a greater concern. While traditional karst surveys are essential for delineating the subsurface extent and morphology of individual caves for speleogenetic interpretation, these methods tend to underestimate the total extent of karst development and require surficial manifestation of karst phenomena. Therefore, this study utilizes a composite suite of remote sensing and traditional field studies for improved karst delineation and detection of potential karst geohazards within gypsum karst. Color InfraRed (CIR imagery were utilized for delineation of lineaments associated with fractures, while Normalized Density Vegetation Index (NDVI analyses were used to delineate regions of increased moisture flux and probable zones of shallow karst development. Digital Elevation Models (DEM constructed from high-resolution LiDAR (Light Detection and Ranging data were used to spatially interpret sinkholes, while analyses of LiDAR intensity data were used in a novel way to categorize local variations in surface geology. Resistivity data, including both direct current (DC and capacitively coupled (CC resistivity analyses, were acquired and interpreted throughout the study area to delineate potential shallow karst geohazards specifically associated with roadways of geohazard concern; however, detailed knowledge of the surrounding geology and local karst development proved essential for proper interpretation of resistivity inversions. The composite suite of traditional field investigations and remotely sensed karst

  16. Gypsum karst in Great Britain

    Directory of Open Access Journals (Sweden)

    Cooper A.H.

    1996-01-01

    Full Text Available In Great Britain the most spectacular gypsum karst development is in the Zechstein gypsum (late Permian mainly in north-eastern England. The Midlands of England also has some karst developed in the Triassic gypsum in the vicinity of Nottingham. Along the north-east coast, south of Sunderland, well-developed palaeokarst, with magnificent breccia pipes, was produced by dissolution of Permian gypsum. In north-west England a small gypsum cave system of phreatic origin has been surveyed and recorded. A large actively evolving phreatic gypsum cave system has been postulated beneath the Ripon area on the basis of studies of subsidence and boreholes. The rate of gypsum dissolution here, and the associated collapse lead to difficult civil engineering and construction conditions, which can also be aggravated by water abstraction.

  17. Recent Trends in Karst Geomorphology.

    Science.gov (United States)

    Palmer, Arthur N.

    1984-01-01

    Recent trends related to the karst processes and the evolution of karst landscapes are discussed. The hydrochemical processes responsible for the origin of karst are expanded on to illustrate the present scope of karst studies. These geomorphological studies are combined with concepts and techniques from hydraulics, chemistry, and mathematics. (JN)

  18. Climatic classification of the Karst

    International Nuclear Information System (INIS)

    Eslava Ramirez Jesus Antonio; Bahamon Ayala, Sandra Marcela; Lopez Romero Maria Ines

    2000-01-01

    Climate is one the main factors in forming or modifying Karsts, or its resulting forms. The determining climatic elements of Karst characteristics are humidity, air circulation and temperature. Many Karstic processes show characteristics corresponding to a given climate sequence. In the present article we discuss the relation between climate and Karst as well as a climate classification based on the structure of the Karsts

  19. Karst mapping in the United States: Past, present and future

    Science.gov (United States)

    Weary, David J.; Doctor, Daniel H.

    2015-01-01

    The earliest known comprehensive karst map of the entire USA was published by Stringfield and LeGrand (1969), based on compilations of William E. Davies of the U.S. Geological Survey (USGS). Various versions of essentially the same map have been published since. The USGS recently published new digital maps and databases depicting the extent of known karst, potential karst, and pseudokarst areas of the United States of America including Puerto Rico and the U.S. Virgin Islands (Weary and Doctor, 2014). These maps are based primarily on the extent of potentially karstic soluble rock types, and rocks with physical properties conducive to the formation of pseudokarst features. These data were compiled and refined from multiple sources at various spatial resolutions, mostly as digital data supplied by state geological surveys. The database includes polygons delineating areas with potential for karst and that are tagged with attributes intended to facilitate classification of karst regions. Approximately 18% of the surface of the fifty United States is underlain by significantly soluble bedrock. In the eastern United States the extent of outcrop of soluble rocks provides a good first-approximation of the distribution of karst and potential karst areas. In the arid western states, the extent of soluble rock outcrop tends to overestimate the extent of regions that might be considered as karst under current climatic conditions, but the new dataset encompasses those regions nonetheless. This database will be revised as needed, and the present map will be updated as new information is incorporated.

  20. CT colonography: a survey of general practitioners' knowledge and interest.

    Science.gov (United States)

    Flor, Nicola; Laghi, Andrea; Peri, Mauro; Cornalba, Gianpaolo; Sardanelli, Francesco

    2016-01-01

    To verify the knowledge and interest of general practitioners on computed tomography colonography (CTC). In 2014, a Web-based questionnaire was proposed to all general practitioners of [Milan, Italy]. The questionnaire consisted of ten questions concerning general practitioners' knowledge about CTC, including application of guidelines in clinical scenarios and diagnostic performance. Out of 1,053 general practitioners, 231 (22%), 155 men and 76 women (mean age 58 years), completed the survey. We found a significant difference between the age of responders and that of non-responders (p = 0.0033). Of the 231 responders, 84% were aware of the possibility of using CTC as a method for examining the colon-rectum. However, only 57% were aware about low X-ray exposure delivered by CTC and about the possibility of using a reduced cleansing protocol. Only 48% were aware that CTC accuracy in diagnosing 10-mm or larger polyps and colorectal cancers was similar to that of conventional colonoscopy, while 62% were informed about CTC advantages in comparison with double-contrast barium enema; 59% thought that CTC had a potential role as a screening test; 85-86% suggested CTC in the case of refused or incomplete conventional colonoscopy; 79% suggested immediate conventional colonoscopy in the case of at least one 10-mm polyp. About 54% usually prescribe one CTC every 4-6 months, while 36% never have, 3% one CTC per month, and 7% one every 2-3 months. Ninety-four per cent declared that they were willing to attend a course on CTC. General practitioners have limited knowledge concerning CTC. Radiological societies should fill this gap offering dedicated educational initiatives.

  1. Stochastic simulation of karst conduit networks

    Science.gov (United States)

    Pardo-Igúzquiza, Eulogio; Dowd, Peter A.; Xu, Chaoshui; Durán-Valsero, Juan José

    2012-01-01

    Karst aquifers have very high spatial heterogeneity. Essentially, they comprise a system of pipes (i.e., the network of conduits) superimposed on rock porosity and on a network of stratigraphic surfaces and fractures. This heterogeneity strongly influences the hydraulic behavior of the karst and it must be reproduced in any realistic numerical model of the karst system that is used as input to flow and transport modeling. However, the directly observed karst conduits are only a small part of the complete karst conduit system and knowledge of the complete conduit geometry and topology remains spatially limited and uncertain. Thus, there is a special interest in the stochastic simulation of networks of conduits that can be combined with fracture and rock porosity models to provide a realistic numerical model of the karst system. Furthermore, the simulated model may be of interest per se and other uses could be envisaged. The purpose of this paper is to present an efficient method for conditional and non-conditional stochastic simulation of karst conduit networks. The method comprises two stages: generation of conduit geometry and generation of topology. The approach adopted is a combination of a resampling method for generating conduit geometries from templates and a modified diffusion-limited aggregation method for generating the network topology. The authors show that the 3D karst conduit networks generated by the proposed method are statistically similar to observed karst conduit networks or to a hypothesized network model. The statistical similarity is in the sense of reproducing the tortuosity index of conduits, the fractal dimension of the network, the direction rose of directions, the Z-histogram and Ripley's K-function of the bifurcation points (which differs from a random allocation of those bifurcation points). The proposed method (1) is very flexible, (2) incorporates any experimental data (conditioning information) and (3) can easily be modified when

  2. Forest Landowner Education Interests and Delivery Preferences: A Retrospective Look at Survey Results and Actual Participation

    Science.gov (United States)

    Zobrist, Kevin W.; Rozance, Mary Ann

    2015-01-01

    This article presents survey data on education interests and delivery preferences of small forest landowners in Washington and compares it to actual program participation over 6 years. The survey was conducted in late 2007 to guide development and implementation of a Extension forestry program. The survey found broad interest across many topics…

  3. Profile of Pre-Service Science Teachers Based on STEM Career Interest Survey

    Science.gov (United States)

    Winarno, N.; Widodo, A.; Rusdiana, D.; Rochintaniawati, D.; Afifah, R. M. A.

    2017-09-01

    This study aims to investigate the profile of pre-service science teachers based on STEM (Science, Technology, Engineering, and Mathematics) Career Interest Survey. The study uses descriptive survey method as the research design. Samples collected from 66 preservice science teachers in a university located in Bandung, Indonesia. The results of the study are the profile of pre-service science teachers based on STEM Career Interest Survey shows that the average number of career interest in the field of technology is 4.08, in science 3.80, mathematics 3.39 and engineering 3.30. Pre-service science teachers are found to have interests in the STEM career fields. This research is necessary as there are many instances of people choosing majors or studies that are not in accordance with their interests and talents. The recommendation of this study is to develop learning in pre-service science teachers by using STEM approach.

  4. Tietkens Plain karst - Maralinga

    International Nuclear Information System (INIS)

    James, J.M.

    1988-09-01

    The Tietkens Plain karst is located to the north of Maralinga village which is on the crest of the Ooldea Range on the north and east margin of the Nullarbor Plain in western South Australia. The geology of the carbonate rocks in the Maralinga area is summarised. On Tietkens Plain from 1955 to 1963 nuclear weapons tests dispersed radioactive materials over the Maralinga area. Six nuclear devices were detonated in the air and one was exploded a few metres below the surface. The effect such explosions have on the karst and the possible rate of recovery of its surface are discussed. This report is the record of a visit to the Maralinga area from the 15th -21st November 1986 which involved an inspection of the karst surface together with collection of water, soil and rock samples. Results of the measurements made in order to assess water quality and water contamination by radioactive nuclides are presented. The implications arising from the presence of radioactive materials on the surface and the possibility of their entering and contaminating the groundwater in the area are discussed in the context of the chemistry of uranium and plutonium. The potential for transmission of contaminants through groundwater conduits and aquifers in the dolomite is discussed. Evidence is produced to show that the caves of the Nullabor Plain are not contaminated at present and are unlikely to be so in the future. 21 refs., 2 figs. 3 tabs., ills

  5. Speleogenesis in Dinaric karst area

    Science.gov (United States)

    Garasic, Mladen; Garasic, Davor

    2015-04-01

    Dinaric Karst is one of the largest karst regions in Europe and in the World. It is the paramount karst of Europe and type site of many karst features. Dinaric Karst Area covers an extensive part of the Dinarides, a mountain chain in Southern Europe named after Dinara Mt., an impressive and outstanding rocky wall on the border between Dalmatian part of Croatia and Bosnia and Herzegovina. The Dinaric Karst occupies an area from the Friuli Plain (Doberdo Karst Plateau) and Slovenian mountains near Postojna cave on the northwest, to Skadar Lake and Prokletije Mt. on the southeast, from Central Bosnian Mountains on the northeast, and the Adriatic Sea seafloor with its islands. The Dinarides outspread in a so-called "Dinaric strike" (NW-SE) for 650 km in length and are up to 150 km wide across SW-NE. The biggest part of the Dinaric Karst Area is situated within Croatian territory (continental, Adriatic coastal and seafloor karst) comprising all karst features with exceptional examples exposed on the surface as well as in the underground. Classical karst area is the one situated in Slovenia, where typical karst features were described for the first time. Presentation of the outstanding values of Dinaric karst is based on the values that can be met in Italy, Bosnia and Herzegovina, Montenegro, Serbia and Albania, too. Dinaric Karst is the World's natural heritage because of its unique and outstanding geological characteristics and its living world; some of them are of outstanding natural beauty. Dinaric karst is an integral, compact karst area with extremely great thickness of carbonate rocks of predominantly Mesozoic age which in some areas exceeds 8.000 m. It bears several cycles of karstification thus giving world uniqueness to the area, especially regarding the wealth of submerged karst phenomena, among which vruljes are world unique features. Dinaric karst is one of the largest karst regions in the World. From the scientific perspective, the Dinaric Karst is one of

  6. The Development of the STEM Career Interest Survey (STEM-CIS)

    Science.gov (United States)

    Kier, Meredith W.; Blanchard, Margaret R.; Osborne, Jason W.; Albert, Jennifer L.

    2014-06-01

    Internationally, efforts to increase student interest in science, technology, engineering, and mathematics (STEM) careers have been on the rise. It is often the goal of such efforts that increased interest in STEM careers should stimulate economic growth and enhance innovation. Scientific and educational organizations recommend that efforts to interest students in STEM majors and careers begin at the middle school level, a time when students are developing their own interests and recognizing their academic strengths. These factors have led scholars to call for instruments that effectively measure interest in STEM classes and careers, particularly for middle school students. In response, we leveraged the social cognitive career theory to develop a survey with subscales in science, technology, engineering, and mathematics. In this manuscript, we detail the six stages of development of the STEM Career Interest Survey. To investigate the instrument's reliability and psychometric properties, we administered this 44-item survey to over 1,000 middle school students (grades 6-8) who primarily were in rural, high-poverty districts in the southeastern USA. Confirmatory factor analyses indicate that the STEM-CIS is a strong, single factor instrument and also has four strong, discipline-specific subscales, which allow for the science, technology, engineering, and mathematics subscales to be administered separately or in combination. This instrument should prove helpful in research, evaluation, and professional development to measure STEM career interest in secondary level students.

  7. Survey Regarding the Competence and Interest towards Research of Romanian University Students

    Science.gov (United States)

    Demjén, Beátrix-Aletta; Ciascai, Liliana

    2017-01-01

    The purpose of this study is to find out the respondents' opinion regarding their abilities and interest towards research. The survey was carried out on a sample of 51 respondents that are involved in research activities in the universities of origin. The participants are students from Faculties of Real and Applied Sciences. The results highlight…

  8. A geomorphological strategy for conducting environmental impact assessments in karst areas

    Science.gov (United States)

    Veni, George

    1999-12-01

    In their efforts to protect regional groundwater supplies, governmental agencies are increasingly requiring studies of karst areas and their features. In areas where tracer tests or geophysics are not required, funded, or otherwise feasible, geomorphological methods remain as the primary tool for assessing karst. This study proposes a geomorphologically-based environmental impact assessment strategy for karst areas. While it is supported with results from a study of the karstic Edwards Aquifer recharge zone on the Camp Bullis Military Training Installation, TX, USA, it is based on the study of several karst areas and is generalized to accommodate and be fine-tuned for regional variations. Biological and other resource issues can also be assessed with this strategy. The assessment identifies environmentally sensitive features and areas, as is often required to meet regulatory directives. In karst areas with relatively small features, excavation is a key tool for accurate assessment. Although the results of this study will help to better manage karst areas, proper management must be done on a regional scale. The highly permeable nature of karst precludes adequate management solely on a feature-by-feature basis. Studies on the relationship of water quality to impervious cover show adverse environmental impacts significantly increase when impervious cover exceeds 15% of a surface watershed. The Camp Bullis study finds similar impacts in its groundwater drainage basin, supporting the argument of 15% impervious cover as a regionally effective means of also protecting karst aquifers when coupled with protection of critical areas identified by field surveys.

  9. A national UK survey of radiology trainees special interest choices: what and why?

    Science.gov (United States)

    Parvizi, Nassim; Bhuva, Shaheel

    2017-11-01

    A national survey was designed to better understand factors influencing special interest choices, future aspirations of UK radiology trainees and perceptions of breast radiology. A SurveyMonkey questionnaire was developed and distributed to all radiology trainees in the UK through the British Institute of Radiology, RCR Junior Radiologists Forum and by directly contacting UK training schemes as well as by social media between December 2015 and January 2016. From 21 training schemes across the UK, 232 responses were received. Over half entered radiology after foundation training and 62% were ST1-3; one-fifth of trainees intended to leave the NHS. The most popular special interests were musculoskeletal (18%), abdominal imaging (16%) and neuroradiology (13%). Gynaecological and oncological imaging proved to be the least popular. Strong personal interest, a successful rotation during training, a mix of imaging modalities, direct impact on patient care and job prospects were the most popular factors influencing career choice. Research and potential for private income were the least influential factors. Respondents detailed their perceptions of breast radiology, selecting an awareness of career prospects (41%) and a better trainee experience (36%) as factors that would increase their interest in pursuing it as a career. Understanding the factors that influence special interest choice is essential to addressing the alarming staffing shortfalls that will befall certain radiology special interests. Addressing trainee's preconceptions and improving the trainee experience are key to attracting trainees to breast radiology. Advances in knowledge: This is the first survey of its kind in the UK literature designed to evaluate special interest career choices and the factors that influence those among radiology trainees.

  10. Woodville Karst Plain, North Florida

    OpenAIRE

    2006-01-01

    Map showing the largest mapped underwater cave systems and conduit flow paths confirmed by tracer testing relative to surface streams, sinkholes and potentiometric surface of the Florida aquifer in the Woodville Karst Plain, Florida

  11. Factors affecting interest in cardiothoracic surgery: Survey of North American general surgery residents.

    Science.gov (United States)

    Vaporciyan, Ara A; Reed, Carolyn E; Erikson, Clese; Dill, Michael J; Carpenter, Andrea J; Guleserian, Kristine J; Merrill, Walter

    2009-05-01

    Applications to cardiothoracic surgery (CTS) training programs have declined precipitously. The viewpoints of potential applicants, general surgery residents, have not yet been assessed. Their perceptions are crucial to understanding the cause and formulating appropriate changes in our educational system. An initial survey instrument was content-validated, and the final instrument was distributed electronically between March 24 and May 2, 2008 through 251 general surgery program directors to all Accreditation Council for Graduate Medical Education-accredited general surgery residents (7508). The response rate was 29% (2153 residents; 89% programs). Respondent's demographics matched existing data; 6% were committed to CTS, and 26% reported prior or current interest in CTS. Interest waned after postgraduate year 3. Interest correlated with CTS rotation duration. Of the respondents committed to CTS, 76% had mentors (71% were cardiothoracic surgeons). CTS had the most shortcomings among 9 subspecialties. Job security and availability accounted for 46% of reported shortcomings (3 to 14 times higher than other subspecialties). Work schedule accounted for 25%. Length of training was not a very important factor, although it was identified as an option to increase interest in CTS. Residents who were undecided or uninterested in CTS were twice as likely to cite the ability to balance work and personal life as important than residents who chose CTS. The dominant concern documented in the survey is job security and availability. The importance of mentorship and exposure to CTS faculty in promoting interest was also evident. Decision makers should consider these findings when planning changes in education and the specialty.

  12. Highway runoff in areas of karst topography.

    Science.gov (United States)

    2004-01-01

    Karst terrain is characterized by sinkholes, depressions, caves, and underground drainage, generally underlain by soluble rocks such as limestone and dolomite. Because natural filtration through soil is limited in karst areas, pollutants in highway s...

  13. Interest in genomic SNP testing for prostate cancer risk: a pilot survey.

    Science.gov (United States)

    Hall, Michael J; Ruth, Karen J; Chen, David Yt; Gross, Laura M; Giri, Veda N

    2015-01-01

    Advancements in genomic testing have led to the identification of single nucleotide polymorphisms (SNPs) associated with prostate cancer. The clinical utility of SNP tests to evaluate prostate cancer risk is unclear. Studies have not examined predictors of interest in novel genomic SNP tests for prostate cancer risk in a diverse population. Consecutive participants in the Fox Chase Prostate Cancer Risk Assessment Program (PRAP) (n = 40) and unselected men from surgical urology clinics (n = 40) completed a one-time survey. Items examined interest in genomic SNP testing for prostate cancer risk, knowledge, impact of unsolicited findings, and psychosocial factors including health literacy. Knowledge of genomic SNP tests was low in both groups, but interest was higher among PRAP men (p testing in both groups. Multivariable modeling identified several predictors of higher interest in a genomic SNP test including higher perceived risk (p = 0.025), indicating zero reasons for not wanting testing (vs ≥1 reason) (p = 0.013), and higher health literacy (p = 0.016). Knowledge of genomic SNP testing was low in this sample, but higher among high-risk men. High-risk status may increase interest in novel genomic tests, while low literacy may lessen interest.

  14. [Nursing and industry relations: literature review and conflicts of interest survey].

    Science.gov (United States)

    Nordhausen, Thomas; Lins, Sabine; Panfil, Eva-Maria; Köpke, Sascha; Leino-Kilpi, Helena; Langer, Gero; Meyer, Gabriele

    2015-01-01

    Advanced competencies and tasks of nurses go along with an increasing interest of pharmaceutical companies and manufacturers in nurses as a marketing target. To identify nurses' attitudes, perceptions and behavior regarding industry and marketing strategies. 1) Systematic literature search in Medline via PubMed and CINAHL for international studies on nurses' conflict of interests towards pharmaceutical companies; 2) analysis of a survey with PhD students from two Nursing Science doctoral programs. The review including 16 publications published between 1999 and 2014 and the survey among 82 PhD students revealed comparable results. The majority of nurses already had contact with pharmaceutical companies. Nurses are often uncritical in their attitudes, and suggestibility is claimed to be low. The majority of nurses were not - or at least not sufficiently - provided with conflict of interest training, neither as part of their vocational training nor their continuing education. Conflict of interest seems to be an important topic for nurses. Increasing relevance in the future underpins the need for making nurses more sensitive towards this issue, especially through professional training programs. Copyright © 2015. Published by Elsevier GmbH.

  15. Career interest and perceptions of nephrology: A repeated cross-sectional survey of internal medicine residents.

    Science.gov (United States)

    Daniels, Michael N; Maynard, Sharon; Porter, Ivan; Kincaid, Hope; Jain, Deepika; Aslam, Nabeel

    2017-01-01

    Interest in nephrology careers among internal medicine residents in the United States is declining. Our objective was to assess the impact of the presence of a nephrology fellowship training program on perceptions and career interest in nephrology among internal medicine residents. A secondary objective was to identify commonly endorsed negative perceptions of nephrology among internal medicine residents. This was a repeated cross-sectional survey of internal medicine residents before (Group 1) and 3 years after (Group 2) the establishment of nephrology fellowship programs at two institutions. The primary outcome was the percentage of residents indicating nephrology as a career interest in Group 1 vs. Group 2. Secondary outcomes included the frequency that residents agreed with negative statements about nephrology. 131 (80.9%) of 162 residents completed the survey. 19 (14.8%) residents indicated interest in a nephrology career, with 8 (6.3%) indicating nephrology as their first choice. There was no difference in career interest in nephrology between residents who were exposed to nephrology fellows during residency training (Group 2) and residents who were not (Group 1). The most commonly endorsed negative perceptions of nephrology were: nephrology fellows have long hours/burdensome call (36 [28.1%] of residents agreed or strongly agreed), practicing nephrologists must take frequent/difficult call (35 [27.6%] agreed or strongly agreed), and nephrology has few opportunities for procedures (35 [27.3%] agreed or strongly agreed). More residents in Group 2 agreed that nephrology is poorly paid (8.9% in Group 1 vs. 20.8% in Group 2, P = 0.04), whereas more residents in Group 1 agreed that nephrologists must take frequent/difficult call (40.0% in Group 1 vs. 18.1% in Group 2, P = 0.02). The initiation of a nephrology fellowship program was not associated with an increase in internal medicine residents' interest in nephrology careers. Residents endorsed several negative

  16. Delineating Potential Karst Water-Bearing Structures based on Resistivity Anomalies and Microtremor Analyses-A Case Study in Yunnan Province, China

    Science.gov (United States)

    Gan, F.; Su, C.; Liu, W.; Zhao, W.

    2016-12-01

    Heterogeneity, anisotropy and rugged landforms become challenges for geophysicists to locate drilling site by water-bearing structure profiling in Karst region. If only one geophysical method is used to achieve this objective, low resistivity anomalies deduced to be water-rich zones could actually be zones rich in marl and shale. In this study, integrated geophysical methods were used to locate a favorable drilling position for the provision of karst water to Juede village, which had been experiencing severe water shortages over a prolonged period. According to site conditions and hydrogeological data, appropriate geophysical profiles were conducted, approximately perpendicular to the direction of groundwater flow. In general, significant changes in resistivity occur between water-filled caves/ fractures and competent rocks. Thus, electrical and electromagnetic methods have been widely applied to search for karst groundwater indirectly. First, electrical resistivity tomography was carried out to discern shallow resistivity distributions within the profile where the low resistivity anomalies were of most interest. Second, one short profile of audio-frequency magnetotelluric survey was used to ascertain the vertical and horizontal extent of these low resistivity anomalies. Third, the microtremor H/V spectral ratio method was applied to identify potential water-bearing structures from low resistivity anomalies and to differentiate these from the interference of marl and shale with low resistivity. Finally, anomalous depths were estimated by interpreting Schlumberger sounding data to determine an optimal drilling site. The study shows that karst hydrogeology and geophysical methods can be effectively integrated for the purposes of karst groundwater exploration.

  17. Characterization of Patient Interest in Provider-Based Consumer Health Information Technology: Survey Study.

    Science.gov (United States)

    Featherall, Joseph; Lapin, Brittany; Chaitoff, Alexander; Havele, Sonia A; Thompson, Nicolas; Katzan, Irene

    2018-04-19

    Consumer health information technology can improve patient engagement in their health care and assist in navigating the complexities of health care delivery. However, the consumer health information technology offerings of health systems are often driven by provider rather than patient perspectives and inadequately address patient needs, thus limiting their adoption by patients. Consideration given to patients as stakeholders in the development of such technologies may improve adoption, efficacy, and consumer health information technology resource allocation. The aims of this paper were to measure patient interest in different health system consumer health information technology apps and determine the influence of patient characteristics on consumer health information technology interest. Patients seen at the Cleveland Clinic Neurological Institute were electronically surveyed on their interest in using different consumer health information technology apps. A self-efficacy scale, Patient Health Questionnaire-9 depression screen, and EuroQol 5 dimensions health-related quality of life scale were also completed by patients. Logistic regression was used to determine the influence of patient characteristics on interest in consumer health information technology in the categories of self-management, education, and communication. The majority of 3852 patient respondents had an interest in all technology categories assessed in the survey. The highest interest was in apps that allow patients to ask questions of providers (3476/3852, 90.24%) and to schedule appointments (3211/3839, 83.64%). Patient interest in consumer health information technology was significantly associated with greater depression symptoms, worse quality of life, greater health self-efficacy, and smartphone ownership (Pinformation technology development and their perspectives should consistently guide development efforts. Health systems should consider focusing on consumer health information technologies

  18. Wind turbines in Danish waters - a survey of the authorities' interests, evaluations and recommendations

    International Nuclear Information System (INIS)

    1995-02-01

    The document produced by a committee under the Danish Ministry for Energy and the Environment aims at meeting the current need for clarifying potentials for placing wind turbine arrays in Danish waters. It deals with (a) marine areas which are of especial interest, a fact which would be a barrier for the establishment of wind turbine arrays, and with (b) marine areas in connection with which permission to establish such arrays is only granted after serious consideration of local needs and interests. In connection with (a) special interests are defined: areas with a bird-life protected by European Union (EU) legislation, conservation areas, land where raw materials can be mined etc., places where buildings or ruins etc, of cultural/historical interest are to be found, military training grounds, principal shipping routes, cable and piping locations, or areas where a bridge is planned to be built. In connection with (b), local interests are defined as fishing areas, places included in landscaping projects, areas where there are large numbers of birds, harbours, areas near airports, radio or navigations systems etc., areas where raw materials are to be found, places where Stone Age habitations exist, marine areas where private yachts are sailed, military training areas, etc. A number of Danish fjords are mentioned as being included in the survey which should result in the choice of Danish waters where wind farm arrays could be established. (AB) 15 maps

  19. Internet use and interest among individuals with traumatic brain injury: A consumer survey.

    Science.gov (United States)

    Vaccaro, Monica; Hart, Tessa; Whyte, John; Buchhofer, Regina

    2007-03-01

    To examine experiences among individuals in the USA with traumatic brain injury (TBI) regarding their access to and use of the Internet, problems encountered, and desire for improved Internet access and skills. An in-depth survey was administered as a semi-structured interview to 80 individuals at least 3 months post moderate to severe TBI. Two-thirds of respondents reported having a computer at home, but only half had access to the Internet. Fewer than half were Internet users, as compared to 60% users in the USA population at the time of the survey. However, Internet activities engaged in by users in this sample were comparable to those of the overall population. There was a strong interest in using the Internet among non-users. Most respondents expressed a strong desire for coaching or other training to enhance or develop Internet skills. Reported reasons for Internet non-use in this sample were lack of access and knowledge, versus lack of interest as in the general population. The high interest in using and learning more about the Internet supports the development of interventions to mprove Internet skills for people with TBI.

  20. Are People With Chronic Diseases Interested in Using Telehealth? A Cross-Sectional Postal Survey

    Science.gov (United States)

    Thomas, Clare; Gregory, Alison; Yardley, Lucy; O'Cathain, Alicia; Montgomery, Alan A; Salisbury, Chris

    2014-01-01

    Background There is growing interest in telehealth—the use of technology to support the remote delivery of health care and promote self-management—as a potential alternative to face-to-face care for patients with chronic diseases. However, little is known about what precipitates interest in the use of telehealth among these patients. Objective This survey forms part of a research program to develop and evaluate a telehealth intervention for patients with two exemplar chronic diseases: depression and raised cardiovascular disease (CVD) risk. The survey was designed to explore the key factors that influence interest in using telehealth in these patient groups. Methods Thirty-four general practices were recruited from two different regions within England. Practice records were searched for patients with (1) depression (aged 18+ years) or (2) 10-year risk of CVD ≥20% and at least one modifiable risk factor (aged 40-74 years). Within each general practice, 54 patients in each chronic disease group were randomly selected to receive a postal questionnaire. Questions assessed five key constructs: sociodemographics, health needs, difficulties accessing health care, technology-related factors (availability, confidence using technology, perceived benefits and drawbacks of telehealth), and satisfaction with prior use of telehealth. Respondents also rated their interest in using different technologies for telehealth (phone, email and Internet, or social media). Relationships between the key constructs and interest in using the three mediums of telehealth were examined using multivariable regression models. Results Of the 3329 patients who were sent a study questionnaire, 44.40% completed it (872/1740, 50.11% CVD risk; 606/1589, 38.14% depression). Overall, there was moderate interest in using phone-based (854/1423, 60.01%) and email/Internet-based (816/1425, 57.26%) telehealth, but very little interest in social media (243/1430, 16.99%). After adjusting for health needs

  1. Are people with chronic diseases interested in using telehealth? A cross-sectional postal survey.

    Science.gov (United States)

    Edwards, Louisa; Thomas, Clare; Gregory, Alison; Yardley, Lucy; O'Cathain, Alicia; Montgomery, Alan A; Salisbury, Chris

    2014-05-08

    There is growing interest in telehealth-the use of technology to support the remote delivery of health care and promote self-management-as a potential alternative to face-to-face care for patients with chronic diseases. However, little is known about what precipitates interest in the use of telehealth among these patients. This survey forms part of a research program to develop and evaluate a telehealth intervention for patients with two exemplar chronic diseases: depression and raised cardiovascular disease (CVD) risk. The survey was designed to explore the key factors that influence interest in using telehealth in these patient groups. Thirty-four general practices were recruited from two different regions within England. Practice records were searched for patients with (1) depression (aged 18+ years) or (2) 10-year risk of CVD ≥20% and at least one modifiable risk factor (aged 40-74 years). Within each general practice, 54 patients in each chronic disease group were randomly selected to receive a postal questionnaire. Questions assessed five key constructs: sociodemographics, health needs, difficulties accessing health care, technology-related factors (availability, confidence using technology, perceived benefits and drawbacks of telehealth), and satisfaction with prior use of telehealth. Respondents also rated their interest in using different technologies for telehealth (phone, email and Internet, or social media). Relationships between the key constructs and interest in using the three mediums of telehealth were examined using multivariable regression models. Of the 3329 patients who were sent a study questionnaire, 44.40% completed it (872/1740, 50.11% CVD risk; 606/1589, 38.14% depression). Overall, there was moderate interest in using phone-based (854/1423, 60.01%) and email/Internet-based (816/1425, 57.26%) telehealth, but very little interest in social media (243/1430, 16.99%). After adjusting for health needs, access difficulties, technology

  2. Interest and satisfaction of dentists in practicing periodontics: A survey based on treatment of gingival recession.

    Science.gov (United States)

    Grover, Vishakha; Kapoor, Anoop; Malhotra, Ranjan; Sachdeva, Sonia

    2012-07-01

    Gingival recession is a common occurrence and patients often report to dental clinic with associated problems such as root surface hypersensitivity, esthetic concerns, cervical root abrasions, and root caries that make it a concern for patients. Based upon the fact that gingival recession is an enigma for clinicians because of multitude of etiological factors and plethora of treatment modalities present for its treatment, a survey was conducted to assess knowledge as well as opinion about most common etiology, classification, and preferred treatment of gingival recession and to evaluate the interest and satisfaction of dentists in practicing periodontics. Study design consisted of a cross-sectional online survey, conducted among dentists practicing in state of Punjab, India, in the month of April 2011. A structured online questionnaire consisting of 17 questions evaluating the interest of dentists in periodontics based on knowledge about gingival recession (most of them giving the possibility of multiple choices of answers) was sent to about 300 dentists. Pearson Chi-Square and Mann-Whitney U tests were used for statistical analysis of data collected. P ≤ 0.05 was considered as statistically significant and P ≤ 0.01 considered as highly significant. A greater proportion of periodontists had better knowledge about etiology (P = 0.07), classification (P = 0.000), and treatment of gingival recession (P = 0.000). A greater number of periodontists opted for the surgical modalities to correct the defects produced by gingival recession as compared to non-periodontists and had better interest (P = 0.000) and satisfaction (P = 0.000) in practicing periodontics. The results elucidated that periodontists had better interest and satisfaction in practicing periodontics, and were more inclined towards surgical correction of gingival recession as compared to non-periodontists.

  3. Hidrogeological features of carbonate karst

    Directory of Open Access Journals (Sweden)

    Валерій Васильович Сухов

    2015-07-01

    Full Text Available On the example of loamy-chalky Upper Cretaceous strata (K2cm of Sviatogirsk brachyanticline it has been found out that carbonate karst forms with the participation of different on dynamics and chemical composition kinds of groundwater.Basic chemical reactions that lead to leaching and dissolution of carbonate rocks during their interaction with groundwater have been characterized. Geological, hydrogeological and geochemical conditions of formation of various morphogenetic types of karst - surface (epikarst and deep (hypokarst have been well-grounded.

  4. Career interest and perceptions of nephrology: A repeated cross-sectional survey of internal medicine residents.

    Directory of Open Access Journals (Sweden)

    Michael N Daniels

    Full Text Available Interest in nephrology careers among internal medicine residents in the United States is declining. Our objective was to assess the impact of the presence of a nephrology fellowship training program on perceptions and career interest in nephrology among internal medicine residents. A secondary objective was to identify commonly endorsed negative perceptions of nephrology among internal medicine residents.This was a repeated cross-sectional survey of internal medicine residents before (Group 1 and 3 years after (Group 2 the establishment of nephrology fellowship programs at two institutions. The primary outcome was the percentage of residents indicating nephrology as a career interest in Group 1 vs. Group 2. Secondary outcomes included the frequency that residents agreed with negative statements about nephrology.131 (80.9% of 162 residents completed the survey. 19 (14.8% residents indicated interest in a nephrology career, with 8 (6.3% indicating nephrology as their first choice. There was no difference in career interest in nephrology between residents who were exposed to nephrology fellows during residency training (Group 2 and residents who were not (Group 1. The most commonly endorsed negative perceptions of nephrology were: nephrology fellows have long hours/burdensome call (36 [28.1%] of residents agreed or strongly agreed, practicing nephrologists must take frequent/difficult call (35 [27.6%] agreed or strongly agreed, and nephrology has few opportunities for procedures (35 [27.3%] agreed or strongly agreed. More residents in Group 2 agreed that nephrology is poorly paid (8.9% in Group 1 vs. 20.8% in Group 2, P = 0.04, whereas more residents in Group 1 agreed that nephrologists must take frequent/difficult call (40.0% in Group 1 vs. 18.1% in Group 2, P = 0.02.The initiation of a nephrology fellowship program was not associated with an increase in internal medicine residents' interest in nephrology careers. Residents endorsed several

  5. The Public Health Workforce Interests and Needs Survey: The First National Survey of State Health Agency Employees.

    Science.gov (United States)

    Sellers, Katie; Leider, Jonathon P; Harper, Elizabeth; Castrucci, Brian C; Bharthapudi, Kiran; Liss-Levinson, Rivka; Jarris, Paul E; Hunter, Edward L

    2015-01-01

    Public health practitioners, policy makers, and researchers alike have called for more data on individual worker's perceptions about workplace environment, job satisfaction, and training needs for a quarter of a century. The Public Health Workforce Interests and Needs Survey (PH WINS) was created to answer that call. Characterize key components of the public health workforce, including demographics, workplace environment, perceptions about national trends, and perceived training needs. A nationally representative survey of central office employees at state health agencies (SHAs) was conducted in 2014. Approximately 25,000 e-mail invitations to a Web-based survey were sent out to public health staff in 37 states, based on a stratified sampling approach. Balanced repeated replication weights were used to account for the complex sampling design. A total of 10,246 permanently employed SHA central office employees participated in PH WINS (46% response rate). Perceptions about training needs; workplace environment and job satisfaction; national initiatives and trends; and demographics. Although the majority of staff said they were somewhat or very satisfied with their job (79%; 95% confidence interval [CI], 78-80), as well as their organization (65%; 95% CI, 64-66), more than 42% (95% CI, 41-43) were considering leaving their organization in the next year or retiring before 2020; 4% of those were considering leaving for another job elsewhere in governmental public health. The majority of public health staff at SHA central offices are female (72%; 95% CI, 71-73), non-Hispanic white (70%; 95% CI, 69-71), and older than 40 years (73%; 95% CI, 72-74). The greatest training needs include influencing policy development, preparing a budget, and training related to the social determinants of health. PH WINS represents the first nationally representative survey of SHA employees. It holds significant potential to help answer previously unaddressed questions in public health

  6. Development of a 3D GIS and its application to karst areas

    Science.gov (United States)

    Wu, Qiang; Xu, Hua; Zhou, Wanfang

    2008-05-01

    There is a growing interest in modeling and analyzing karst phenomena in three dimensions. This paper integrates geology, groundwater hydrology, geographic information system (GIS), database management system (DBMS), visualization and data mining to study karst features in Huaibei, China. The 3D geo-objects retrieved from the karst area are analyzed and mapped into different abstract levels. The spatial relationships among the objects are constructed by a dual-linker. The shapes of the 3D objects and the topological models with attributes are stored and maintained in the DBMS. Spatial analysis was then used to integrate the data in the DBMS and the 3D model to form a virtual reality (VR) to provide analytical functions such as distribution analysis, correlation query, and probability assessment. The research successfully implements 3D modeling and analyses in the karst area, and meanwhile provides an efficient tool for government policy-makers to set out restrictions on water resource development in the area.

  7. Interest of LQAS method in a survey of HTLV-I infection in Benin (West Africa).

    Science.gov (United States)

    Houinato, Dismand; Preux, Pierre-Marie; Charriere, Bénédicte; Massit, Bruno; Avodé, Gilbert; Denis, François; Dumas, Michel; Boutros-Toni, Fernand; Salamon, Roger

    2002-02-01

    HTLV-I is heterogeneously distributed in Sub-Saharan Africa. Traditional survey methods as cluster sampling could provide information for a country or region of interest. However, they cannot identify small areas with higher prevalences of infection to help in the health policy planning. Identification of such areas could be done by a Lot Quality Assurance Sampling (LQAS) method, which is currently used in industry to identify a poor performance in assembly lines. The LQAS method was used in Atacora (Northern Benin) between March and May 1998 to identify areas with a HTLV-I seroprevalence higher than 4%. Sixty-five subjects were randomly selected in each of 36 communes (lots) of this department. Lots were classified as unacceptable when the sample contained at least one positive subject. The LQAS method identified 25 (69.4 %) communes with a prevalence higher than 4%. Using stratified sampling theory, the overall HTLV-I seroprevalence was 4.5% (95% CI: 3.6-5.4%). These data show the interest of LQAS method application under field conditions to detect clusters of infection.

  8. Interest in web-based treatments for postpartum anxiety: an exploratory survey.

    Science.gov (United States)

    Ashford, Miriam T; Ayers, Susan; Olander, Ellinor K

    2017-09-01

    This study aimed to explore women's interest in web-based treatments for postpartum anxiety and determine the feasibility of reaching women with postpartum anxiety online. Anxiety in the postpartum period is common and often untreated. One innovative approach of offering treatment during this period is through web-based self-help. Assessing women's interest in new treatments, such as a web-based self-help, is an important step prior to development efforts. A cross-sectional online survey was created and promoted for 4 months via unpaid social media posts (Facebook and Twitter). To be eligible, women had to be over the age of 18, live in England, fluent in English, be within 12 months postpartum and self-report at least mild levels of anxiety. A sample of 114 eligible women were recruited. The majority were Caucasian, well-educated, middle-class women. Seventy percent reported moderate or severe anxiety. Sixty-one percent of women expressed interest in web-based postpartum anxiety treatments. Women preferred treatment in a smartphone/tablet application format, presented in brief modules and supported by a therapist via email or chat/instant messaging. Based on the stated preferences of participating women it is recommended that postpartum anxiety web-based treatments include different forms of therapist support and use a flexibly accessible smartphone/tablet application format with content split into short sections. The findings also suggest that unpaid social media can be feasible in reaching women with postpartum anxiety, but additional efforts are needed to reach a more diverse population.

  9. Digital engineering aspects of Karst map: a GIS version of Davies, W.E., Simpson, J.H., Ohlmacher, G.C., Kirk, W.S., and Newton, E.G., 1984, Engineering aspects of Karst: U.S. Geological Survey, National Atlas of the United States of America, Scale 1:7,500,000

    Science.gov (United States)

    Tobin, Bret D.; Weary, David J.

    2004-01-01

    These data are digital facsimiles of the original 1984 Engineering Aspects of Karst map by Davies and others. This data set was converted from a printed map to a digital GIS coverage to provide users with a citable national scale karst data set to use for graphic and demonstration purposes until new, improved data are developed. These data may be used freely with proper citation. Because it has been converted to GIS format, these data can be easily projected, displayed and queried for multiple uses in GIS. The karst polygons of the original map were scanned from the stable base negatives of the original, vectorized, edited and then attributed with unit descriptions. All of these processes potentially introduce small errors and distortions to the geography. The original map was produced at a scale of 1:7,500,000; this coverage is not as accurate, and should be used for broad-scale purposes only. It is not intended for any site-specific studies.

  10. Norway spruce (Picea abies/L./Karst.) health status on various forest soil ecological series in Silesian Beskids obtained by grid or selective survey

    Czech Academy of Sciences Publication Activity Database

    Samec, Pavel; Edwards-Jonášová, Magda; Cudlín, Pavel

    2017-01-01

    Roč. 10, 1-2 (2017), s. 57-66 ISSN 1803-2451 R&D Projects: GA MŠk LD15044; GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : spruce decline * survey design * defoliation * forest site ecological series Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) https://beskydy.mendelu.cz/10/1/0057/

  11. River-groundwater connectivity in a karst system, Wellington, New South Wales, Australia

    Science.gov (United States)

    Keshavarzi, Mohammadreza; Baker, Andy; Kelly, Bryce F. J.; Andersen, Martin S.

    2017-03-01

    The characterization of river-aquifer connectivity in karst environments is difficult due to the presence of conduits and caves. This work demonstrates how geophysical imaging combined with hydrogeological data can improve the conceptualization of surface-water and groundwater interactions in karst terrains. The objective of this study is to understand the association between the Bell River and karst-alluvial aquifer at Wellington, Australia. River and groundwater levels were continuously monitored, and electrical resistivity imaging and water quality surveys conducted. Two-dimensional resistivity imaging mapped the transition between the alluvium and karst. This is important for highlighting the proximity of the saturated alluvial sediments to the water-filled caves and conduits. In the unsaturated zone the resistivity imaging differentiated between air- and sediment-filled karst features, and in the saturated zone it mapped the location of possible water- and sediment-filled caves. Groundwater levels are dynamic and respond quickly to changes in the river stage, implying that there is a strong hydraulic connection, and that the river is losing and recharging the adjacent aquifer. Groundwater extractions (1,370 ML, megalitres, annually) from the alluvial aquifer can cause the groundwater level to fall by as much as 1.5 m in a year. However, when the Bell River flows after significant rainfall in the upper catchment, river-leakage rapidly recharges the alluvial and karst aquifers. This work demonstrates that in complex hydrogeological settings, the combined use of geophysical imaging, hydrograph analysis and geochemical measurements provide insights on the local karst hydrology and groundwater processes, which will enable better water-resource and karst management.

  12. A glossary of Karst terminology

    Science.gov (United States)

    Monroe, Watson Hiner

    1970-01-01

    This glossary includes most terms used in describing karst geomorphologic features and processes. The terms are primarily those used in the literature of English-speaking countries, but a few of the more common terms in French, German, and Spanish are included, with references to the corresponding English terms where they are available. The glossary also includes simple definitions of the more common rocks and minerals found in karst terrain, common terms of hydrology, and a number of the descriptive terms used by speleologists. The glossary does not include definitions of most biospeleological terms, geologic structure terms, varieties of carbonate rock that require microscopic techniques for identification, or names describing tools and techniques of cave exploration.

  13. Pilot project 'Karst water Dachstein'. Vol. 2: karst hydrology and contamination risk in springs

    International Nuclear Information System (INIS)

    Scheidleder, A.; Mandl, G.W.; Boroviczeny, F.; Hofmann, T.; Schubert, G.; Trimborn, P.; Stichler, W.; Graf, W.

    2001-01-01

    The pilot project 'Karstwasser Dachstein' aimed to ascertain the karst groundwater quality of one of the largest karst massifs in Austria, to examine and quantity the factors influencing karst groundwater quality and to gain experience in the monitoring of karst groundwater quality (Austrian Water Quality Monitoring System). The first phase of the pilot project examined comprehensively the factors influencing and the potential threats endangering karst water quality and was finished in 1994 with Vol. 1 entitled 'Karstwasserqualitaet' (HERLICSKA and LORBEER). The present study is based on the findings of the first phase of the project and aims to combine, analyze and assess the extensive quantity of data material with, special emphasis on karst hydrology and the contamination risk in springs. The interdisciplinary data analysis and the hydrogeological interpretation were carried out by the Austrian Federal Environment Agency (UBA), the Geological Survey of Austria (GBA) and the National Research Centre for Environment and Health (GSF). Their work was based on the detailed description of the geological conditions in the Dachstein area, on the thorough examination of chemical and physical spring water parameters, an isotope analyses of precipitation and spring waters as well as on the results of several tracer experiments and an investigations of the potential impacts of human activities. Investigations of the bacteriological contamination of the spring waters showed that there were only 6 out of 42 springs where there was no evidence of coliform bacteria or faecal germs. These 6 springs are all situated in the southern part of the Dachstein massif. For the analyses carried out to determine the content of chlorinated hydrocarbons, detection limits had been set very low. In all springs, evidence of chlorinated hydrocarbons was found at least once. These concentrations were all below the maximum allowable concentrations set out in the Groundwater Threshold Value

  14. The current status of mapping karst areas and availability of public sinkhole-risk resources in karst terrains of the United States

    Science.gov (United States)

    Kuniansky, Eve L.; Weary, David J.; Kaufmann, James E.

    2016-01-01

    Subsidence from sinkhole collapse is a common occurrence in areas underlain by water-soluble rocks such as carbonate and evaporite rocks, typical of karst terrain. Almost all 50 States within the United States (excluding Delaware and Rhode Island) have karst areas, with sinkhole damage highest in Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania. A conservative estimate of losses to all types of ground subsidence was $125 million per year in 1997. This estimate may now be low, as review of cost reports from the last 15 years indicates that the cost of karst collapses in the United States averages more than $300 million per year. Knowing when a catastrophic event will occur is not possible; however, understanding where such occurrences are likely is possible. The US Geological Survey has developed and maintains national-scale maps of karst areas and areas prone to sinkhole formation. Several States provide additional resources for their citizens; Alabama, Colorado, Florida, Indiana, Iowa, Kentucky, Minnesota, Missouri, Ohio, and Pennsylvania maintain databases of sinkholes or karst features, with Florida, Kentucky, Missouri, and Ohio providing sinkhole reporting mechanisms for the public.

  15. Urang Cave Karst Environmental Development, as Tourism Object

    Directory of Open Access Journals (Sweden)

    Srijono Srijono

    2013-12-01

    Full Text Available Karst environment become an alternative tourist destination as well as to boost local revenues. In karst environments in Grobogan District, Central Java Province, formed Urang Cave, with an interesting endokarst phenomenon. This study aims to do zoning district Urang Cave as tourist sites. The research method is using contour maps as a base map of Urang Cave karst environment geomorphological mapping. Geomorphological data processing is using ArcView GIS 3.3 program. Land use map refers to RBI, scale 1:25.000. Geomorphological analysis refers to the Ministry of Energy and Mineral Resources No. 1456.K/20/MEM/2000, and petrography. Each development zone is analyzed its geophysical environmental element, then set scoring and value summation. For comprehensive environmental element analysis, chemical analysis of rocks, and water-soil chemistry. In reference to Minister of Energy Mineral Resource decrees No. 1456/K/20/MEM/2000, Urang Cave zoning defined into 3 (three zone, as follow: the Protected Zone, Cultivation Zone 1, and Cultivation Zone 2. Protected Zone, consists of Urang Cave tunnel/hallway with a unique spheleothem in it. This zone as a cave tracking site tourism, potential to produce karst water as a decent drinking water while maintaining hardness. Cultivation Zone 1 is spreading about 200 m in distance from outer appearance of spring around the cave hallway. In this zone mining of cave sediments may be done in the inactive form caves, without changing the state of the existing major exokarst morphology. Cultivation Zone 2, an outer zone, located farthest from the tunnel/hallway Urang Cave. Utilization of this zone as a limestone mining quarry, although only on a small scale.

  16. Karst in evaporites in southeastern New Mexico

    International Nuclear Information System (INIS)

    Bachman, G.O.

    1987-09-01

    Permian evaporites in southeastern New Mexico include gypsum, anhydrite, and salt, which are subject to both blanket and local, selective dissolution. Dissolution has produced many hundreds of individual karst features including collapse sinks, karst valleys, blind valleys, karst plains, caves, and breccia pipes. Dissolution began within some formations during Permian time and has been intermittent but continual ever since. Karst features other than blanket deposits of breccia are not preserved from the early episodes of dissolution, but some karst features preserved today - such as breccia pipes - are remnants of karst activity that was active at least as early as mid-Pleistocene time. Rainfall was much more abundant during Late Pleistocene time, and many features visible today may have been formed then. The drainage history of the Pecos River is related to extensive karstification of the Pecos Valley during mid-Pleistocene time. Large-scale stream piracy and dissolution of salt in the subsurface resulted in major shifts and excavations in the channel. In spite of intensive groundwater studies that have been carried out in the region, major problems in near-surface evaporite karst remain to be solved. Among these are determination of recharge areas and time of recharge. 109 refs., 31 figs., 1 tab

  17. Identification of karst sinkholes in a forested karst landscape using airborne laser scanning data and water flow analysis

    Science.gov (United States)

    Hofierka, Jaroslav; Gallay, Michal; Bandura, Peter; Šašak, Ján

    2018-05-01

    Karst sinkholes (dolines) play an important role in a karst landscape by controlling infiltration of surficial water, air flow or spatial distribution of solar energy. These landforms also present a limiting factor for human activities in agriculture or construction. Therefore, mapping such geomorphological forms is vital for appropriate landscape management and planning. There are several mapping techniques available; however, their applicability can be reduced in densely forested areas with poor accessibility and visibility of the landforms. In such conditions, airborne laser scanning (ALS) provides means for efficient and accurate mapping of both land and landscape canopy surfaces. Taking the benefits of ALS into account, we present an innovative method for identification and evaluation of karst sinkholes based on numerical water flow modelling. The suggested method was compared to traditional techniques for sinkhole mapping which use topographic maps and digital terrain modelling. The approach based on simulation of a rainfall event very closely matched the reference datasets derived by manual inspection of the ALS digital elevation model and field surveys. However, our process-based approach provides advantage of assessing the magnitude how sinkholes influence concentration of overland water flow during extreme rainfall events. This was performed by calculating the volume of water accumulated in sinkholes during the simulated rainfall. In this way, the influence of particular sinkholes on underground geomorphological systems can be assessed. The method was demonstrated in a case study of Slovak Karst in the West Carpathians where extreme rainfalls or snow-thaw events occur annually. We identified three spatially contiguous groups of sinkholes with a different effect on overland flow concentration. These results are discussed in relation to the known underground hydrological systems.

  18. Students' Interest and Experiences in Physics and Chemistry Related Themes: Reflections Based on a ROSE-Survey in Finland

    Science.gov (United States)

    Lavonen, Jari; Byman, Reijo; Uitto, Anna; Juuti, Kalle; Meisalo, Veijo

    2008-01-01

    Interest in physics and chemistry topics and out-of-school experiences of Finnish secondary school students (n = 3626, median age 15) were surveyed using the international ROSE questionnaire. Based on explorative factor analysis the scores of six out-of-school experience factors (indicating how often students had done something outside of school)…

  19. Reporting of financial and non-financial conflicts of interest by authors of systematic reviews: a methodological survey.

    Science.gov (United States)

    Hakoum, Maram B; Anouti, Sirine; Al-Gibbawi, Mounir; Abou-Jaoude, Elias A; Hasbani, Divina Justina; Lopes, Luciane Cruz; Agarwal, Arnav; Guyatt, Gordon; Akl, Elie A

    2016-08-10

    Conflicts of interest may bias the findings of systematic reviews. The objective of this methodological survey was to assess the frequency and different types of conflicts of interest that authors of Cochrane and non-Cochrane systematic reviews report. We searched for systematic reviews using the Cochrane Database of Systematic Reviews and Ovid MEDLINE (limited to the 119 Core Clinical Journals and the year 2015). We defined a conflict of interest disclosure as the reporting of whether a conflict of interest exists or not, and used a framework to classify conflicts of interest into individual (financial, professional and intellectual) and institutional (financial and advocatory) conflicts of interest. We conducted descriptive and regression analyses. Of the 200 systematic reviews, 194 (97%) reported authors' conflicts of interest disclosures, typically in the main document, and in a few cases either online (2%) or on request (5%). Of the 194 Cochrane and non-Cochrane reviews, 49% and 33%, respectively, had at least one author reporting any type of conflict of interest (p=0.023). Institutional conflicts of interest were less frequently reported than individual conflicts of interest, and Cochrane reviews were more likely to report individual intellectual conflicts of interest compared with non-Cochrane reviews (19% and 5%, respectively, p=0.004). Regression analyses showed a positive association between reporting of conflicts of interest (at least one type of conflict of interest, individual financial conflict of interest, institutional financial conflict of interest) and journal impact factor and between reporting individual financial conflicts of interest and pharmacological versus non-pharmacological intervention. Although close to half of the published systematic reviews report that authors (typically many) have conflicts of interest, more than half report that they do not. Authors reported individual conflicts of interest more frequently than institutional and

  20. Survey of CAM interest, self-care, and satisfaction with health care for type 2 diabetes at group health cooperative

    Directory of Open Access Journals (Sweden)

    Bradley Ryan

    2011-12-01

    Full Text Available Abstract Background Very little research has explored the factors that influence interest in complementary and alternative medicine (CAM treatments. We surveyed persons with sub-optimally controlled type 2 diabetes to evaluate potential relationships between interest in complementary and alternative medicine (CAM treatments, current self-care practices, motivation to improve self-care practices and satisfaction with current health care for diabetes. Methods 321 patients from a large integrated healthcare system with type 2 diabetes, who were not using insulin and had hemoglobin A1c values between 7.5-9.5%, were telephoned between 2009-2010 and asked about their self-care behaviors, motivation to change, satisfaction with current health care and interest in trying naturopathic (ND care for their diabetes. Responses from patients most interested in trying ND care were compared with those from patients with less interest. Results 219 (68.5% patients completed the survey. Nearly half (48% stated they would be very likely to try ND care for their diabetes if covered by their insurance. Interest in trying ND care was not related to patient demographics, health history, clinical status, or self-care behaviors. Patients with greater interest in trying ND care rated their current healthcare as less effective for controlling their blood sugar (mean response 5.9 +/- 1.9 vs. 6.6 +/- 1.5, p = 0.003, and were more determined to succeed in self-care (p = 0.007. Current CAM use for diabetes was also greater in ND interested patients. Conclusions Patients with sub-optimally controlled type 2 diabetes expressed a high level of interest in trying ND care. Those patients with the greatest interest were less satisfied with their diabetes care, more motivated to engage in self-care, and more likely to use other CAM therapies for their diabetes.

  1. International interest rate convergence: a survey of the issues and evidence

    OpenAIRE

    Charles Pigott

    1993-01-01

    World financial markets have become substantially integrated over the last two decades. Contrary to widespread expectations, however, this integration has not led to any greater convergence of interest rates across countries. This article examines why convergence has not occurred and more generally what financial integration does—and does not—mean for international interest rate relations.

  2. Interest in international surgical volunteerism: results of a survey of members of the American Pediatric Surgical Association.

    Science.gov (United States)

    Butler, Marilyn W; Krishnaswami, Sanjay; Rothstein, David H; Cusick, Robert A

    2011-12-01

    This study assesses interest in international volunteer work by members of the American Pediatric Surgical Association (APSA) and attempts to identify demographics, motivations, obstacles, and institutional issues of the respondents. An online survey service was used to send a 25-question survey to all APSA members with email addresses in November 2009. An answer to all questions was not required. Written comments were encouraged. The survey was sent to 807 members of whom 316 responded, for a response rate of 39%. International work had been done previously by 48% of respondents, whereas 95% stated that they were interested or perhaps interested in doing so. Most (83%) were interested in operating with local surgeons to teach them how to perform procedures. Altruism was the chief motivation in 75% of respondents. Primary obstacles to doing international work were family obligations and lack of time, although 37% stated that a lack of information about volunteer opportunities was an issue. A significant number of respondents (48%) stated that their institution had no established international collaborations. This study suggests that there is interest in international volunteerism among many members of APSA. Understanding the issues surrounding surgical volunteerism may facilitate humanitarian involvement among pediatric surgeons. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Isotopic study of Karst water

    International Nuclear Information System (INIS)

    Leskovsek-Sefman, H.

    1985-01-01

    Measurement of the isotopic composition of water formed part of an extended investigation of the water drainage system in the Slovenian Karst. These studies were planned to complement geological and speleological investigations which are already being performed in this area, with the knowledge of the mechanism of changes in the isotopic composition of water in the natural environment on some smaller locations, Planina cave near Postojna where the vertical percolation of meteoric water through the karstified carbonate ceiling was studied and the water catchment areas of some small rivers, Ljubljanica, Rizana and Idrijca. Mass spectrometric investigations of the isotopic composition of some elements ( 18 O, D, 13 C and T) in water and in dissolved carbonates, as well as the isotopic composition of 18 O and 13 C in cave carbonates were performed. The results allow to conclude that the waters in karst aquifers in spite of producing the homogenisation to a great extent, qualitative determination of the retention time and of the prevailing sources for some springs and surface and underground water flows is nevertheless possible. The isotopic composition of 18 O in water and of 18 O and 13 C in dissolved carbonates depends on climatic conditions and on denudation processes. The investigation of cave carbonates revealed that they have different isotopic compositions of 18 O and 13 C because of different locations and also different ages

  4. TEAM Science Advances STEM through Experiential Learning about Karst Geology at the Ozark Underground Laboratory.

    Science.gov (United States)

    Haskins, M. F.; Patterson, J. D.; Ruckman, B.; Keith, N.; Aley, C.; Aley, T.

    2017-12-01

    Carbonate karst represents approximately 14% of the world's land area and 20-25% of the land area in the United States. Most people do not understand this three dimensional landscape because they lack direct experience with this complicated geology. For the last 50 years, Ozark Underground Laboratory (OUL), located in Protem, MO, has been a pioneer in the research of karst geology and its influence on groundwater. OUL has also provided surface and sub-surface immersion experiences to over 40,000 individuals including students, educators, and Department of Transportation officials helping those individuals better understand the challenges associated with karst. Rockhurst University has incorporated OUL field trips into their educational programming for the last 30 years, thus facilitating individual understanding of karst geology which comprises approximately 60% of the state. Technology and Educators Advancing Missouri Science (TEAM Science) is a grant-funded professional development institute offered through Rockhurst University. The institute includes an immersion experience at OUL enabling in-service teachers to better understand natural systems, the interplay between the surface, sub-surface, and cave fauna, as well as groundwater and energy dynamics of karst ecosystems. Educating elementary teachers about land formations is especially important because elementary teachers play a foundational role in developing students' interest and aptitude in STEM content areas. (Funding provided by the U.S. Department of Education's Math-Science Partnership Program through the Missouri Department of Elementary and Secondary Education.)

  5. Calculation of the Strip Foundation on Solid Elastic Base, Taking into Account the Karst Collapse

    Science.gov (United States)

    Sharapov, R.; Lodigina, N.

    2017-07-01

    Karst processes greatly complicate the construction and operation of buildings and structures. Due to the karstic deformations at different times there have been several major accidents, which analysis showed that in all cases the fundamental errors committed at different stages of building development: site selection, engineering survey, design, construction or operation of the facilities. Theory analysis of beams on elastic foundation is essential in building practice. Specialist engineering facilities often have to resort to multiple designing in finding efficient forms of construction of these facilities. In work the calculation of stresses in cross-sections of the strip foundation evenly distributed load in the event of karst. A comparison of extreme stress in the event of karst and without accounting for the strip foundation as a beam on an elastic foundation.

  6. Modern and Unconventional Approaches to Karst Hydrogeology

    Science.gov (United States)

    Sukop, M. C.

    2017-12-01

    Karst hydrogeology is frequently approached from a hydrograph/statistical perspective where precipitation/recharge inputs are converted to output hydrographs and the conversion process reflects the hydrology of the system. Karst catchments show hydrological response to short-term meteorological events and to long-term variation of large-scale atmospheric circulation. Modern approaches to analysis of these data include, for example, multiresolution wavelet techniques applied to understand relations between karst discharge and climate fields. Much less effort has been directed towards direct simulation of flow fields and transport phenomena in karst settings. This is primarily due to the lack of information on the detailed physical geometry of most karst systems. New mapping, sampling, and modeling techniques are beginning to enable direct simulation of flow and transport. A Conduit Flow Process (CFP) add-on to the USGS ModFlow model became available in 2007. FEFLOW and similar models are able to represent flows in individual conduits. Lattice Boltzmann models have also been applied to flow modeling in karst systems. Regarding quantitative measurement of karst system geometry, at scales to 0.1 m, X-ray computed tomography enables good detection of detailed (sub-millimeter) pore space in karstic rocks. Three-dimensional printing allows reconstruction of fragile high porosity rocks, and surrogate samples generated this way can then be subjected to laboratory testing. Borehole scales can be accessed with high-resolution ( 0.001 m) Digital Optical Borehole Imaging technologies and can provide virtual samples more representative of the true nature of karst aquifers than can obtained from coring. Subsequent extrapolation of such samples can generate three-dimensional models suitable for direct modeling of flow and transport. Finally, new cave mapping techniques are beginning to provide information than can be applied to direct simulation of flow. Due to flow rates and cave

  7. Adaptation of the Science, Technology, Engineering, and Mathematics Career Interest Survey (STEM-CIS) into Turkish

    Science.gov (United States)

    Koyunlu Unlu, Zeynep; Dokme, Ilbilge; Unlu, Veli

    2016-01-01

    Problem Statement: Science, technology, engineering, and mathematics (STEM) education has recently become a remarkable research topic, especially in developed countries as a result of the skilled workforce required in the fields of the STEM. Considering that professional tendencies are revealed at early ages, determining students' interest in STEM…

  8. Professional Development Needs and Training Interests: A Survey of Early Career School Psychologists

    Science.gov (United States)

    Arora, Prerna G.; Brown, Jacqueline; Harris, Bryn; Sullivan, Amanda

    2017-01-01

    Early career psychologists (ECPs) are considered a distinct professional group that faces unique career challenges. Despite recent organizational efforts to increase engagement of these individuals, little is known about the professional development needs and training interests of ECPs, particularly within psychology's subfields. As such, this…

  9. Barriers to Office-Based Mental Health Care and Interest in E-Communication With Providers: A Survey Study.

    Science.gov (United States)

    Rai, Minnie; Vigod, Simone N; Hensel, Jennifer M

    2016-08-01

    With rising availability and use of Internet and mobile technology in society, the demand and need for its integration into health care is growing. Despite great potential within mental health care and growing uptake, there is still little evidence to guide how these tools should be integrated into traditional care, and for whom. To examine factors that might inform how e-communication should be implemented in our local outpatient mental health program, including barriers to traditional office-based care, patient preferences, and patient concerns. We conducted a survey in the waiting room of our outpatient mental health program located in an urban, academic ambulatory hospital. The survey assessed (1) age, mobile phone ownership, and general e-communication usage, (2) barriers to attending office-based appointments, (3) preferences for, and interest in, e-communication for mental health care, and (4) concerns about e-communication use for mental health care. We analyzed the data descriptively and examined associations between the presence of barriers, identifying as a social media user, and interest level in e-communication. Respondents (N=68) were predominantly in the age range of 25-54 years. The rate of mobile phone ownership was 91% (62/68), and 59% (40/68) of respondents identified as social media users. There was very low existing use of e-communication between providers and patients, with high levels of interest endorsed by survey respondents. Respondents expressed an interest in using e-communication with their provider to share updates and get feedback, coordinate care, and get general information. In regression analysis, both a barrier to care and identifying as a social media user were significantly associated with e-communication interest (P=.03 and P=.003, respectively). E-communication interest was highest among people who both had a barrier to office-based care and were a social media user. Despite high interest, there were also many concerns

  10. Robust resilience and substantial interest: a survey of pharmacological cognitive enhancement among university students in the UK and Ireland.

    Directory of Open Access Journals (Sweden)

    Ilina Singh

    Full Text Available Use of 'smart drugs' among UK students is described in frequent media reports as a rapidly increasing phenomenon. This article reports findings from the first large-scale survey of pharmacological cognitive enhancement (PCE among students in the UK and Ireland. Conducted from February to September 2012, a survey of a convenience sample of 877 students measured PCE prevalence, attitudes, sources, purposes and ethics. Descriptive and logistic regression statistical methods were used to analyse the data. Lifetime prevalence of PCE using modafinil, methylphenidate or Adderall was under 10%, while past regular and current PCE users of these substances made up between 0.3%-4% of the survey population. A substantial majority of students was unaware of and/or uninterested in PCE; however about one third of students were interested in PCE. PCE users were more likely to be male, British and older students; predictors of PCE use included awareness of other students using PCEs, ADHD symptomatology, ethical concerns, and alcohol and cannabis use. The survey addresses the need for better evidence about PCE prevalence and practices among university students in the UK. We recommend PCE-related strategies for universities based on the survey findings.

  11. The use of karst geomorphology for planning, hazard avoidance and development in Great Britain

    Science.gov (United States)

    Cooper, Anthony H.; Farrant, Andrew R.; Price, Simon J.

    2011-11-01

    Within Great Britain five main types of karstic rocks - dolomite, limestone, chalk, gypsum and salt - are present. Each presents a different type and severity of karstic geohazard which are related to the rock solubility and geological setting. Typical karstic features associated with these rocks have been databased by the British Geological Survey (BGS) with records of sinkholes, cave entrances, stream sinks, resurgences and building damage; data for more than half of the country has been gathered. BGS has manipulated digital map data, for bedrock and superficial deposits, with digital elevation slope models, superficial deposit thickness models, the karst data and expertly interpreted areas, to generate a derived dataset assessing the likelihood of subsidence due to karst collapse. This dataset is informed and verified by the karst database and marketed as part of the BGS GeoSure suite. It is currently used by environmental regulators, the insurance and construction industries, and the BGS semi-automated enquiry system. The database and derived datasets can be further combined and manipulated using GIS to provide other datasets that deal with specific problems. Sustainable drainage systems, some of which use soak-aways into the ground, are being encouraged in Great Britain, but in karst areas they can cause ground stability problems. Similarly, open loop ground source heat or cooling pump systems may induce subsidence if installed in certain types of karstic environments such as in chalk with overlying sand deposits. Groundwater abstraction also has the potential to trigger subsidence in karst areas. GIS manipulation of the karst information is allowing Great Britain to be zoned into areas suitable, or unsuitable, for such uses; it has the potential to become part of a suite of planning management tools for local and National Government to assess the long term sustainable use of the ground.

  12. Best Interest of the Child and Parental Alienation: A Survey of State Statutes.

    Science.gov (United States)

    Baker, Amy J L; Asayan, Mariann; LaCheen-Baker, Alianna

    2016-07-01

    State statutes regarding the best interests of the child (BIC) in deciding disputed custody were reviewed and independently coded with respect to three issues (i) the child's preference and any limits (ii) parental alienation and (iii) psychological maltreatment. Results revealed that many states allowed for the child's preferences to be considered and none qualified that preference when undue influence has occurred; parental alienation as a term was not found in any state statutes but 70% of the states included at least one BIC factor relevant to its core construct of the parent supporting the child's relationship to the other parent; and many states included a history of domestic violence or child abuse but only three states explicitly mentioned psychological maltreatment. These findings highlight yet another way in which the BICS factors lack specificity in ways that could negatively impact children caught in their parents' conflict. © 2016 American Academy of Forensic Sciences.

  13. 76 FR 61379 - Final Recovery Plan, Bexar County Karst Invertebrates

    Science.gov (United States)

    2011-10-04

    ...] Final Recovery Plan, Bexar County Karst Invertebrates AGENCY: Fish and Wildlife Service, Interior... availability of our final recovery plan, for the nine Bexar County Karst Invertebrates under the Endangered... County karst invertebrates were listed as endangered species on December 26, 2000 (65 FR 81419): Rhadine...

  14. Strong smoker interest in 'setting an example to children' by quitting: national survey data.

    Science.gov (United States)

    Thomson, George; Wilson, Nick; Weerasekera, Deepa; Edwards, Richard

    2011-02-01

    To further explore smoker views on reasons to quit. As part of the multi-country ITC Project, a national sample of 1,376 New Zealand adult (18+ years) smokers was surveyed in 2007/08. This sample included boosted sampling of Māori, Pacific and Asian New Zealanders. 'Setting an example to children' was given as 'very much' a reason to quit by 51%, compared to 45% giving personal health concerns. However, the 'very much' and 'somewhat' responses (combined) were greater for personal health (81%) than 'setting an example to children' (74%). Price was the third ranked reason (67%). In a multivariate analysis, women were significantly more likely to state that 'setting an example to children' was 'very much' or 'somewhat' a reason to quit; as were Māori, or Pacific compared to European; and those suffering financial stress. The relatively high importance of 'example to children' as a reason to quit is an unusual finding, and may have arisen as a result of social marketing campaigns encouraging cessation to protect families in New Zealand. The policy implications could include a need for a greater emphasis on social reasons (e.g. 'example to children'), in pack warnings, and in social marketing for smoking cessation. © 2011 The Authors. ANZJPH © 2010 Public Health Association of Australia.

  15. Deep reversible storage - proposition of an area of interest for an extended survey and of surface implantation scenarios

    International Nuclear Information System (INIS)

    2009-01-01

    This document first describes the approach taken for the selection of a site. It presents and discusses the implantation criteria with respect to geology and to long term safety, the technical criteria for a surface implantation (environmental and safety constraints, social and economical data, transport infrastructures). Then, it states the first propositions for different scenarios of surface and underground implantations. It gives an assessment of the dialog with local actors. It presents the ANDRA's proposition in terms of technical criteria, area of interest for an extended survey, and surface implantation scenarios to be investigated

  16. Offering the full range of contraceptive options: a survey of interest in vasectomy training in the US family planning community.

    Science.gov (United States)

    Nguyen, Brian T; Jochim, Andrea L; Shih, Grace H

    2017-05-01

    To assess current practices regarding female and male sterilization counseling and provision, as well as determine interest in providing vasectomy among family planning specialists. Members of the US-based network of family planning fellowship physicians (current fellows, graduates and faculty) received a Web-based survey from November 2015 through January 2016 regarding current sterilization preferences and practices, as well as interest in obtaining training in vasectomy counseling and procedure. Nearly 60% (n=178/302) of family planning fellowship providers responded to the survey. While 62% (111/178) of respondents reported counseling their patients about vasectomy at least most of the time and 57% (102/178) recommended vasectomy over female sterilization, few (8/178; 4 trained in family medicine and 4 trained in obstetrics and gynecology) had performed a vasectomy in the last year. Nearly 90% (158/178) of respondents were somewhat or very interested in receiving training on vasectomy counseling; 58% (103/178) desired procedural training. Desire for training was associated with being male and receiving residency training in family medicine. Few family planning fellowship physicians provide vasectomy, and the majority expressed being at least somewhat interested in receiving further training. Vasectomy is more effective, safer and less expensive than female sterilization but is less common than female sterilization. One barrier to vasectomy access is the low number of vasectomy providers. Creating a structured vasectomy training program through the family planning fellowship may help to increase the number of vasectomy providers. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Karst in Wadi Bani Khalid, Oman

    Science.gov (United States)

    Abdelaziz, Ramadan

    2017-04-01

    There are several important in Oman. The main aquifer is surficial aquifer and fractured rocks. In fact, the geology of Oman is complex whichmake the hydraulic continuity of bedrock is limited and formaing localized aquifers. caves in Oman are varying types and length, size and geographic formations. Many caves and valleys founded in Oman. Wadi Bani Khalid hosts complex network of fractured rock. Karst in Wadi Bani Kalid made upof Limestone(Calcium, which is dissolve in water.A rain water pass through the rock it is erode the rock and form caves. The cave located in Miqil. The karst was formed in Calcium Carbonate rocks.

  18. Characterisation of the heterogeneity of karst using electrical geophysics - applications in SW China

    Science.gov (United States)

    Binley, A. M.; Cheng, Q.; Tao, M.; Chen, X.

    2017-12-01

    The southwest China karst region is one of the largest globally continuous karst areas. The great (structural, hydrological and geochemical) complexity of karstic environments and their rapidly evolving nature make them extremely vulnerable to natural and anthropogenic processes/activities. Characterising the location and properties of structures within the karst critical zone, and understanding how the landform is evolving is essential for the mitigation and adaption to locally- and globally-driven changes. Because of the specific nature of karst geology and geomorphology in the humid tropics and subtropics, spatial heterogeneity is high, evidenced by specific landforms features. Such heterogeneity leads to a high dynamic variability of hydrological processes in space and time, along with a complex exchange of surface water and groundwater. Investigating karst hydrogeological features is extremely challenging because of the three-dimensional nature of the system. Observations from boreholes can vary significantly over several metres, making conventional aquifer investigative methods limited. Geophysical methods have emerged as potentially powerful tools for hydrogeological investigations. Geophysical surveys can help to obtain more insight into the complex conduit networks and depth of weathering, both of which can provide quantitative information about the hydrological and hydrochemical dynamics of the system, in addition to providing a better understanding of how critical zone structures have been established and how the landscape is evolving. We present here results from recent geophysical field campaigns in SW China. We illustrate the effectiveness of electrical methods for mapping soil infil in epikarst and report results from field-based investigations along hillslope and valley transects. Our results reveal distinct zones of relatively high electrical conductivity to depths of tens of metres, which we attribute to localised increased fracture density. We

  19. Impact Of Online Advertising On Consumer Attitudes And Interests Buy Online Survey On Students Of Internet Users In Makassar

    Directory of Open Access Journals (Sweden)

    Muhammad Aqsa

    2015-04-01

    Full Text Available ABSTRACT The rapid development of technology today makes Internet users continues to increase. This is supported by the ease of internet users access the internet either through a PC laptop mobile phones tablets and other media. The increase in Internet users this makes the internet into a proper promotion using online advertising. With a wide reach and touch the various layers of the Internet media communities may be appropriate advice for company promotion. However an increasing number of Internet users especially in the city of Makassar is not accompanied by an increase in the number of online purchases. Based on that it is necessary to examine how the effect of online advertising on consumer buying behavior and online as well as how to control the behavior and subjective norms influence the attitudes and interests of consumers buy online. This study aims to analyze and test the effect of online advertising on consumer attitudes and purchase interest online a survey conducted on students of Internet users in the city of Makassar. The study was conducted on students of public and private universities in the city of Makassar. The method used was a quantitative analysis using the technique of purposive sampling method with a sample of 340 people. Testing this hypothesis using structural equation modeling SEM. The results showed that online advertising has an influence on consumer buying behavior and online. Dimensions interactivity of online advertising provides the highest influence on the attitudes and interests of consumers purchasing online.

  20. Long distance seawater intrusion through a karst conduit network in the Woodville Karst Plain, Florida

    OpenAIRE

    Zexuan Xu; Seth Willis Bassett; Bill Hu; Scott Barrett Dyer

    2016-01-01

    Five periods of increased electrical conductivity have been found in the karst conduits supplying one of the largest first magnitude springs in Florida with water. Numerous well-developed conduit networks are distributed in the Woodville Karst Plain (WKP), Florida and connected to the Gulf of Mexico. A composite analysis of precipitation and electrical conductivity data provides strong evidence that the increases in conductivity are directly tied to seawater intrusion moving inland and travel...

  1. A review of stormwater management in karst

    Science.gov (United States)

    Stormwater management can be a challenge in any environment, but it is especially difficult in karst terrain. The characteristic dissolution of bedrock creates depressions in topography as well as voids in the subsurface, resulting in problems such as collapse sinkhole development, groundwater cont...

  2. Conduit enlargement in an eogenetic karst aquifer

    Science.gov (United States)

    Moore, Paul J.; Martin, Jonathan B.; Screaton, Elizabeth J.; Neuhoff, Philip S.

    2010-11-01

    SummaryMost concepts of conduit development have focused on telogenetic karst aquifers, where low matrix permeability focuses flow and dissolution along joints, fractures, and bedding planes. However, conduits also exist in eogenetic karst aquifers, despite high matrix permeability which accounts for a significant component of flow. This study investigates dissolution within a 6-km long conduit system in the eogenetic Upper Floridan aquifer of north-central Florida that begins with a continuous source of allogenic recharge at the Santa Fe River Sink and discharges from a first-magnitude spring at the Santa Fe River Rise. Three sources of water to the conduit include the allogenic recharge, diffuse recharge through epikarst, and mineralized water upwelling from depth. Results of sampling and inverse modeling using PHREEQC suggest that dissolution within the conduit is episodic, occurring only during 30% of 16 sampling times between March 2003 and April 2007. During low flow conditions, carbonate saturated water flows from the matrix to the conduit, restricting contact between undersaturated allogenic water with the conduit wall. When gradients reverse during high flow conditions, undersaturated allogenic recharge enters the matrix. During these limited periods, estimates of dissolution within the conduit suggest wall retreat averages about 4 × 10 -6 m/day, in agreement with upper estimates of maximum wall retreat for telogenetic karst. Because dissolution is episodic, time-averaged dissolution rates in the sink-rise system results in a wall retreat rate of about 7 × 10 -7 m/day, which is at the lower end of wall retreat for telogenetic karst. Because of the high permeability matrix, conduits in eogenetic karst thus enlarge not just at the walls of fractures or pre-existing conduits such as those in telogenetic karst, but also may produce a friable halo surrounding the conduits that may be removed by additional mechanical processes. These observations stress the

  3. Discovery of and Interest in Health Apps Among Those With Mental Health Needs: Survey and Focus Group Study.

    Science.gov (United States)

    Schueller, Stephen M; Neary, Martha; O'Loughlin, Kristen; Adkins, Elizabeth C

    2018-06-11

    A large number of health apps are available directly to consumers through app marketplaces. Little information is known, however, about how consumers search for these apps and which factors influence their uptake, adoption, and long-term use. The aim of this study was to understand what people look for when they search for health apps and the aspects and features of those apps that consumers find appealing. Participants were recruited from Northwestern University's Center for Behavioral Intervention Technologies' research registry of individuals with mental health needs. Most participants (n=811) completed a survey asking about their use and interest in health and mental health apps. Local participants were also invited to participate in focus groups. A total of 7 focus groups were conducted with 30 participants that collected more detailed information about their use and interest in health and mental health apps. Survey participants commonly found health apps through social media (45.1%, 366/811), personal searches (42.7%, 346/811), or word of mouth (36.9%, 299/811), as opposed to professional sources such as medical providers (24.6%, 200/811). From the focus groups, common themes related to uptake and use of health apps included the importance of personal use before adoption, specific features that users found desirable, and trusted sources either developing or promoting the apps. As the number of mental health and health apps continue to increase, it is imperative to better understand the factors that impact people's adoption and use of such technologies. Our findings indicated that a number of factors-ease of use, aesthetics, and individual experience-drove adoption and use and highlighted areas of focus for app developers and disseminators. ©Stephen M Schueller, Martha Neary, Kristen O'Loughlin, Elizabeth C Adkins. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 11.06.2018.

  4. Do Karst Rivers “deserve” their own biotic index? A ten years study on macrozoobenthos in Croatia

    Directory of Open Access Journals (Sweden)

    Rađa Biljana

    2010-07-01

    Full Text Available In this study we present the results of a ten year survey of the aquatic macroinvertebrate fauna along four karst rivers: Jadro, Žrnovnica, Grab and Ruda, all of them situated in the Middle Dalmatia region of Croatia, in an attempt to construct the Iliric Biotic Index, which will be more applicable for the water quality analysis than the most frequently applied biotic index in Croatia, the Italian Modification of Extended Biotic Index. The rivers geologically belong to the Dinaric karst, unique geological phenomena in Europe. Benthic macroinvertebrates were collected along each river at 15 sites by standard methods of sampling along with several physicochemical parameters, including: temperature, dissolved oxygen, carbon dioxide, alkalinity, hardness and pH. Univariate and multivariate techniques revealed differences in the macroinvertebrate community structure as well as in physicochemical parameters between the Karst rivers and continental rivers. Based on those differences, the Iliric Biotic Index was proposed as the standard of karst river water quality in Croatia in accordance with the EU Water Framework Directive. Differences between the Iliric Biotic Index and the most commonly used biotic indices in the European Community and the USA (The Biological Monitoring Working Party (B.M.W.P. scores, i.e. Extended Biotic Index, Indice Biotique, Family Biotic Index suggest that karst rivers need a new biotic index.

  5. Reply to Discussion by Zekai Șen on "Modeling karst spring hydrograph recession based on head drop at sinkholes"

    Science.gov (United States)

    Field, Malcolm S.; Goldscheider, Nico; Li, Guangquan

    2018-02-01

    We are pleased to learn that the model presented in our paper dealing with the "modeling karst spring hydrograph recession based on head drop at sinkholes," published in the Journal of Hydrology in 2016 (Li et al., 2016), is of interest to readers of this journal. Our study presented a new non-exponential model for assessing spring hydrographs in terms of head drop at flooded sinkholes, as an extension of an earlier model proposed by Li and Field (2014). In both papers, we used two spring hydrographs measured in the St. Marks Karst Watershed in northwest Florida to test the applicability and to verify the validity of our models.

  6. Speleogenesis, geometry, and topology of caves: A quantitative study of 3D karst conduits

    Science.gov (United States)

    Jouves, Johan; Viseur, Sophie; Arfib, Bruno; Baudement, Cécile; Camus, Hubert; Collon, Pauline; Guglielmi, Yves

    2017-12-01

    Karst systems are hierarchically spatially organized three-dimensional (3D) networks of conduits behaving as drains for groundwater flow. Recently, geostatistical approaches proposed to generate karst networks from data and parameters stemming from analogous observed karst features. Other studies have qualitatively highlighted relationships between speleogenetic processes and cave patterns. However, few studies have been performed to quantitatively define these relationships. This paper reports a quantitative study of cave geometries and topologies that takes the underlying speleogenetic processes into account. In order to study the spatial organization of caves, a 3D numerical database was built from 26 caves, corresponding to 621 km of cumulative cave passages representative of the variety of karst network patterns. The database includes 3D speleological surveys for which the speleogenetic context is known, allowing the polygenic karst networks to be divided into 48 monogenic cave samples and classified into four cave patterns: vadose branchwork (VB), water-table cave (WTC), looping cave (LC), and angular maze (AM). Eight morphometric cave descriptors were calculated, four geometrical parameters (width-height ratio, tortuosity, curvature, and vertical index) and four topological ones (degree of node connectivity, α and γ graph indices, and ramification index) respectively. The results were validated by statistical analyses (Kruskal-Wallis test and PCA). The VB patterns are clearly distinct from AM ones and from a third group including WTC and LC. A quantitative database of cave morphology characteristics is provided, depending on their speleogenetic processes. These characteristics can be used to constrain and/or validate 3D geostatistical simulations. This study shows how important it is to relate the geometry and connectivity of cave networks to recharge and flow processes. Conversely, the approach developed here provides proxies to estimate the evolution of

  7. [Distribution of 137Cs and relative influencing factors on typical karst sloping land].

    Science.gov (United States)

    Zhang, Xiao-Nan; Wang, Ke-Lin; Zhang, Wei; Chen, Hong-Song; He, Xun-Yang; Zhang, Xin-Bao

    2009-11-01

    Based on the field survey and the analysis of a large number of soil samples, the distribution of 137 Cs and its influencing factors were studied using 137 Cs tracer technology on typical karst sloping land. The results indicate that the distribution of 137 Cs in soil profile in karst areas show the similar characteristics as that in non-karst areas, fitted an exponential pattern in forest soils and a uniform pattern in cultivated soils. In the sinkhole points in karst areas, 137 Cs exists in deep soil layers and its specific activity vary from 1.7 to 3.3 Bq/kg in soil layers above 45cm, suggesting the existing soil around karst sinkhole is mainly formed by the accumulation of erosion materials. The 137 Cs specific activity in the soil from two rock cracks are 16.8 Bq/kg and 37.6 Bq/kg respectively, which are much higher than that in the soil around the rock, this phenomenon indicates that bare rock is an important influencing factor for 137 Cs spatial movement. With the increment of altitude, the 137 Cs area activity exhibits an irregular fluctuation and evident spatial heterogeneity. On the forest land, the 137 Cs area activities which range from 299.4 to 1 592.6 Bq/m2 are highly positively correlated with the slope gradient and positively correlated with the altitude; while on the cultivated land, the 137 Cs area activities which range from 115.8 to 1478.6 Bq/m2 are negatively correlated with the slope gradient but negatively correlated with the altitude. Topography, geomorphology and human disturbance intensity are the key factors influencing 137 Cs spatial distribution.

  8. Crveno jezero - the biggest sinkhole in Dinaric Karst (Croatia)

    Science.gov (United States)

    Garasic, M.

    2012-04-01

    Red Lake is ONE OF THE DEEPEST KARST (CAVE) LAKES IN THE WORLD and its deepest measured level of -281 METERS is still not the deepest point of the lake! It is a water storage containing more than 16,000,000 cubic meters of water. More accurate figures will be obtained in the course of future explorations to be undertaken by a special kind of bathyscaph. The Red Lake is the world's largest documented and surveyed ground water storage in karst, and deserves to be appreciated as such.

  9. Karst database development in Minnesota: Design and data assembly

    Science.gov (United States)

    Gao, Y.; Alexander, E.C.; Tipping, R.G.

    2005-01-01

    The Karst Feature Database (KFD) of Minnesota is a relational GIS-based Database Management System (DBMS). Previous karst feature datasets used inconsistent attributes to describe karst features in different areas of Minnesota. Existing metadata were modified and standardized to represent a comprehensive metadata for all the karst features in Minnesota. Microsoft Access 2000 and ArcView 3.2 were used to develop this working database. Existing county and sub-county karst feature datasets have been assembled into the KFD, which is capable of visualizing and analyzing the entire data set. By November 17 2002, 11,682 karst features were stored in the KFD of Minnesota. Data tables are stored in a Microsoft Access 2000 DBMS and linked to corresponding ArcView applications. The current KFD of Minnesota has been moved from a Windows NT server to a Windows 2000 Citrix server accessible to researchers and planners through networked interfaces. ?? Springer-Verlag 2005.

  10. Sulphate rocks as an arena for karst development

    Directory of Open Access Journals (Sweden)

    Andrejchuk V.

    1996-01-01

    Full Text Available The rocks in which karst systems develop are most commonly composed of carbonate sulphate and chloride minerals. The sulphate minerals are quite numerous, but only gypsum and anhydrite form extensive masses in sedimentary sequences. Other minerals, which represent sulphates of K, Mg and Na, normally occur as minor beds (0.1-5.0 m, or as inclusions associated with chloride rocks. However some minerals precipitated in salt-generating basins, such as mirabilite and glauberite (typically formed in the Kara-Bogaz-Gol Gulf, salt lakes of Siberia and in China, form sequences up to 5-10 m thick where karst may develop. Due to the very high solubility of Na -sulphates, karst processes and features occurring in these rocks resemble salt karst. Thus, the term sulphate karst, although not strictly correct, is used mainly to indicate karst developed in gypsum and anhydrite.

  11. Planning and design considerations in karst terrain

    Science.gov (United States)

    Fischer, J. A.; Greene, R. W.; Ottoson, R. S.; Graham, T. C.

    1988-10-01

    This article discusses the various steps that the authors feel are necessary to the successful progression of an engineered project sited in karst terrain. The procedures require a multidisciplined approach with liaison and cooperation among the various parties to the project. Initially, the prospective owner must have sufficient understanding of the potential engineering problems to incorporate the engineering geologist into the early stages of any planned acquisition. The first step in an investigation should include a review of the available geologic information, aerial photo interpretation, consultation with the State Geological Survey, and a geologic reconnaissance of the prospective site and surrounding area. A go-no-go decision as to purchase can often been made at an early time. Although, in some instances, more study is needed for a particularly intriguing property. The second stage should consider the various planning alternatives that are feasible based upon the limited available information. At this stage planning/purchase decisions can be made as to purchasing options, value of the property, design constraints, and the possible economic penalties that could be associated with the potential site construction. Various planning and construction alternatives should be considered in this phase of the work. The third stage should include a site investigation program of moderate size, consisting of test pits and/or exploratory borings. The borings should be drilled using water as the drilling fluid, with an experienced crew and qualified technical inspection. The authors find the use of geophysical techniques can be extremely misleading unless used in conjunction with exploratory drilling. Successful evaluations using geophysical procedures occur only under ideal conditions. The geotechnical viability of the plan and preliminary design should be investigated in the fourth phase. Additionally, the physical parameters required for the design of structures

  12. Patient Smartphone Ownership and Interest in Mobile Apps to Monitor Symptoms of Mental Health Conditions: A Survey in Four Geographically Distinct Psychiatric Clinics

    OpenAIRE

    Torous, John; Chan, Steven Richard; Yee-Marie Tan, Shih; Behrens, Jacob; Mathew, Ian; Conrad, Erich J; Hinton, Ladson; Yellowlees, Peter; Keshavan, Matcheri

    2014-01-01

    Background: Despite growing interest in mobile mental health and utilization of smartphone technology to monitor psychiatric symptoms, there remains a lack of knowledge both regarding patient ownership of smartphones and their interest in using such to monitor their mental health. Objective: To provide data on psychiatric outpatients’ prevalence of smartphone ownership and interest in using their smartphones to run applications to monitor their mental health. Methods: We surveyed 320 psychiat...

  13. Karst Depression Detection Using ASTER, ALOS/PRISM and SRTM-Derived Digital Elevation Models in the Bambuí Group, Brazil

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    Osmar Abílio de Carvalho

    2013-12-01

    Full Text Available Remote sensing has been used in karst studies to identify limestone terrain, describe exokarst features, analyze karst depressions, and detect geological structures important to karst development. The aim of this work is to investigate the use of ASTER-, SRTM- and ALOS/PRISM-derived digital elevation models (DEMs to detect and quantify natural karst depressions along the São Francisco River near Barreiras city, northeast Brazil. The study area is a karst landscape characterized by karst depressions (dolines, closed depressions in limestone, many of which contain standing water connected with the ground-water table. The base of dolines is typically sealed with an impermeable clay layer covered by standing water or herbaceous vegetation. We identify dolines by combining the extraction of sink depth from DEMs, morphometric analysis using GIS, and visual interpretation. Our methodology is a semi-automatic approach involving several steps: (a DEM acquisition; (b sink-depth calculation using the difference between the raw DEM and the corresponding DEM with sinks filled; and (c elimination of falsely identified karst depressions using morphometric attributes. The advantages and limitations of the applied methodology using different DEMs are examined by comparison with a sinkhole map generated from traditional geomorphological investigations based on visual interpretation of the high-resolution remote sensing images and field surveys. The threshold values of the depth, area size and circularity index appropriate for distinguishing dolines were identified from the maximum overall accuracy obtained by comparison with a true doline map. Our results indicate that the best performance of the proposed methodology for meso-scale karst feature detection was using ALOS/PRISM data with a threshold depth > 2 m; areas > 13,125 m2 and circularity indexes > 0.3 (overall accuracy of 0.53. The overall correct identification of around half of the true dolines suggests

  14. Facilitating out-of-home caregiving through health information technology: survey of informal caregivers' current practices, interests, and perceived barriers.

    Science.gov (United States)

    Zulman, Donna M; Piette, John D; Jenchura, Emily C; Asch, Steven M; Rosland, Ann-Marie

    2013-07-10

    Many patients with chronic conditions are supported by out-of-home informal caregivers-family members, friends, and other individuals who provide care and support without pay-who, if armed with effective consumer health information technology, could inexpensively facilitate their care. We sought to understand caregivers' use of, interest in, and perceived barriers to health information technology for out-of-home caregiving. We conducted 2 sequential Web-based surveys with a national sample of individuals who provide out-of-home caregiving to an adult family member or friend with a chronic illness. We queried respondents about their use of health information technology for out-of-home caregiving and used multivariable regression to investigate caregiver and care-recipient characteristics associated with caregivers' technology use for caregiving. Among 316 out-of-home caregiver respondents, 34.5% (109/316) reported using health information technology for caregiving activities. The likelihood of a caregiver using technology increased significantly with intensity of caregiving (as measured by number of out-of-home caregiving activities). Compared with very low intensity caregivers, the adjusted odds ratio (OR) of technology use was 1.88 (95% CI 1.01-3.50) for low intensity caregivers, 2.39 (95% CI 1.11-5.15) for moderate intensity caregivers, and 3.70 (95% CI 1.62-8.45) for high intensity caregivers. Over 70% (149/207) of technology nonusers reported interest in using technology in the future to support caregiving. The most commonly cited barriers to technology use for caregiving were health system privacy rules that restrict access to care-recipients' health information and lack of familiarity with programs or websites that facilitate out-of-home caregiving. Health information technology use for out-of-home caregiving is common, especially among individuals who provide more intense caregiving. Health care systems can address the mismatch between caregivers' interest

  15. Self-reported cardiac risks and interest in risk modification among volunteer firefighters: a survey-based study.

    Science.gov (United States)

    Scanlon, Patrick; Ablah, Elizabeth

    2008-12-01

    Coronary heart disease causes approximately 45% of firefighter deaths annually. Although firefighters have clinically significant cardiac risks, a paucity of research and data exists. To evaluate firefighters' cardiac risk factors as well as their motivation to resolve these risk factors. During a 3-month period, volunteer firefighters representing the 79 fire departments serving Nassau and Suffolk counties in Long Island, NY, were asked to complete a nonvalidated, 19-item questionnaire regarding their health habits, medical history, and demographics. A total of 730 surveys were returned among a potential study population of 20,590 volunteer firefighters. More than three-quarters of respondents met the criteria for being overweight or obese, and nearly 40% reported having high blood pressure, high cholesterol, or both. Most respondents expressed at least some interest in attending a fire department-sponsored health lecture and participating in a fitness program. Firefighters expressed desire to learn more about risk factor modifications and have fire departments take a more active role in helping firefighters improve their health. The effectiveness of resources and intervention programs should be assessed.

  16. A nationwide survey of healthcare personnel’s attitude, knowledge, and interest toward renal supportive care in Taiwan

    Directory of Open Access Journals (Sweden)

    Hung-Bin Tsai

    2017-07-01

    Full Text Available Background Renal supportive care (RSC is an important option for elderly individuals reaching end-stage renal disease; however, the frequency of RSC practice is very low among Asian countries. We evaluated the attitude, the knowledge, and the preference for specific topics concerning RSC among participants who worked in different medical professions in Taiwan. Methods A cross-sectional questionnaire-based survey was employed. Healthcare personnel (N = 598 who were involved in caring for end-stage renal disease patients at more than 40 facilities in Taiwan participated in this study. Participants were asked about their motivation for learning about RSC, the topics of RSC they were most and least interested in, their willingness to provide RSC, and to rate their knowledge and perceived importance of different topics. Results The vast majority of respondents (81.9% were self-motivated about RSC, among whom nephrologists (96.8% and care facilitators (administrators/volunteers (45% exhibited the highest and the least motivation, respectively (p < 0.01. Overall, respondents indicated that they had adequate knowledge about the five pre-specified RSC topics between medical professions (p = 0.04. Medical professions and institutional size exerted significant influence on the willingness to provide RSC. Conclusions Our results facilitate the understanding of the knowledge and attitude toward different RSC topics among varied medical professions, and can guide the design of RSC education content for healthcare personnel.

  17. Evaporite karst of northern lower Michigan

    Science.gov (United States)

    Black, T.J.

    1997-01-01

    Michigan has three main zones of evaporite karst: collapse breccia in Late Silurian deposits of the Mackinac Straits region; breccia, collapse sinks, and mega-block collapse in Middle Devonian deposits of Northern Lower Michigan, which overlaps the preceding area; and areas of soil swallows in sinks of Mississippian deposits between Turner and Alabaster in Arenac and Iosco counties, and near Grand Rapids in Kent County. The author has focused his study on evaporite karst of the Middle Devonian deposits. The Middle Devonian depos its are the Detroit River Group: a series consisting of limestone, dolomite, shale, salt, gypsum, and anhydrite. The group occurs from subcrop, near the surface, to nearly 1400 feet deep from the northern tip of the Southern Peninsula to the south edge of the "solution front" Glacial drift is from zero to 350 feet thick. Oil and gas exploration has encountered some significant lost-circulation zones throughout the area. Drilling without fluid returns, casing-seal failures, and lost holes are strong risks in some parts of the region. Lost fluid returns near the top of the group in nearby areas indicate some karst development shortly after deposition. Large and irregular lost-circulation zones, linear and patch trends of large sink holes, and 0.25 mile wide blocks of down-dropped land in the northern Lower Peninsula of Michigan were caused by surface- and ground-water movement along faults into the Detroit River Group. Glaciation has removed some evidence of the karst area at the surface. Sinkhole development, collapse valleys, and swallows developed since retreat of the glacier reveal an active solution front in the Detroit River Group.

  18. Topographic and Hydrographic GIS Datasets for the Afghanistan Geological Survey and U.S. Geological Survey 2014 Mineral Areas of Interest

    Science.gov (United States)

    DeWitt, Jessica D.; Chirico, Peter G.; Malpeli, Katherine C.

    2015-11-18

    Mineral extraction and associated industries play an important role in the Afghan economy, particularly in the “transitional era” of declining foreign aid and withdrawal of foreign troops post 2014. In addition to providing a substantial source of government revenue, other potential benefits of natural resource development include boosted exports, employment opportunities, and strengthened industrialization (Joya, 2012). Continued exploration and investment in these industries has resulted in large economic improvements since 2007, when this series of studies was initiated. At that time, the “Preliminary Non-Fuel Mineral Resource Assessment of Afghanistan” was completed by members of the U.S. Geological Survey and Afghanistan Geological Survey (Peters and others, 2007). The assessment published a series of country-wide datasets, including a digital elevation model (DEM), elevation contours, hydrography, transportation routes, geophysics, and cultural datasets (Peters and others, 2007). It also delineated 20 mineralized areas for further study using a geologic-based methodology. A second data product, “Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan,” was released by Peters and others in 2011. This work highlighted geologic, geohydrologic, and hyperspectral studies that were carried out in specific Areas of Interest (AOIs) to assess the location and characteristics of mineral resources. Also included in the 2011 publication is a collection of appendixes and inventories of Geographic Information System (GIS) datasets for each of the 24 identified AOIs. A third data product was released in 2013 (Casey and Chirico, 2013), publishing datasets for five different AOIs, two subareas, and one AOI extension. Each dataset contains vector shapefiles of the AOI boundary, streams, roads, and contours at 25-, 50-, and 100-meter (m) intervals, as well as raster files of the AOI’s DEM and hillshade.

  19. Topographic and hydrographic GIS datasets for the Afghan Geological Survey and U.S. Geological Survey 2013 mineral areas of interest

    Science.gov (United States)

    Casey, Brittany N.; Chirico, Peter G.

    2013-01-01

    Afghanistan is endowed with a vast amount of mineral resources, and it is believed that the current economic state of the country could be greatly improved through investment in the extraction and production of these resources. In 2007, the “Preliminary Non-Fuel Resource Assessment of Afghanistan 2007” was completed by members of the U.S. Geological Survey and Afghan Geological Survey (Peters and others, 2007). The assessment delineated 20 mineralized areas for further study using a geologic-based methodology. In 2011, a follow-on data product, “Summaries and Data Packages of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan,” was released (Peters and others, 2011). As part of this more recent work, geologic, geohydrologic, and hyperspectral studies were carried out in the areas of interest (AOIs) to assess the location and characteristics of the mineral resources. The 2011 publication included a dataset of 24 identified AOIs containing subareas, a corresponding digital elevation model (DEM), elevation contours, areal extent, and hydrography for each AOI. In 2012, project scientists identified five new AOIs and two subareas in Afghanistan. These new areas are Ahankashan, Kandahar, Parwan, North Bamyan, and South Bamyan. The two identified subareas include Obatu-Shela and Sekhab-ZamtoKalay, both located within the larger Kandahar AOI. In addition, an extended Kandahar AOI is included in the project for water resource modeling purposes. The dataset presented in this publication consists of the areal extent of the five new AOIs, two subareas, and the extended Kandahar AOI, elevation contours at 100-, 50-, and 25-meter intervals, an enhanced DEM, and a hydrographic dataset covering the extent of the new study area. The resulting raster and vector layers are intended for use by government agencies, developmental organizations, and private companies in Afghanistan to assist with mineral assessments, monitoring

  20. Destruction of dolines: the examples from Slovene karst

    Science.gov (United States)

    Kovacic, G.; Ravbar, N.

    2012-04-01

    Due to the absence of soil and flat agricultural land, in karst regions, the cultivation of doline bottoms and the clearing of stones on fields and meadows were traditional methods of adapting farming practices to the landscape with limited agricultural potential. In recent years, a variety of activities resulting from comprehensive economic and urban development have increased pressure on karst landscapes. In some areas the surface and the underground are increasingly threatened by industrial activities, uncontrolled settlement and spread of infrastructure, the development of tourism, and intensive agrarian land use. Unsupervised human encroachment on karst landscapes is causing the increasingly more frequent and more widespread degradation of karst relief forms. The intensive reshaping of the landscape has expanded beyond control largely as a result of technological development and mechanization. The excessive modern filling of dolines, as one of the most distinctive karst surface features, has become a major encroachment on the environment for leveling purposes. Such kind of human influence affects the shape of karst features and the appearance of the landscape as well as the intensity of karst processes such as corrosion. Many dolines are filled with general and construction waste, which threatens the existence of unique habitats and quality of groundwater and consequently water supply. This contribution presents some cases of inappropriate management of karst landscape in Slovenia and examines the national legislative framework on spatial planning in karst regions. Unfortunately, in the current legislation, the standards and conditions for the protection of karst landscape characteristics (e.g. dolines) are loose and not fully elaborated. Principally, there are no uniform mechanisms to protect specific relief forms or for the adequate protection of karst. To a large extent, the preservation of the characteristic karst landscape is left to local communities

  1. Improving Geologic and Engineering Models of Midcontinent Fracture and Karst-Modified Reservoirs Using New 3-D Seismic Attributes

    Energy Technology Data Exchange (ETDEWEB)

    Susan Nissen; Saibal Bhattacharya; W. Lynn Watney; John Doveton

    2009-03-31

    Our project goal was to develop innovative seismic-based workflows for the incremental recovery of oil from karst-modified reservoirs within the onshore continental United States. Specific project objectives were: (1) to calibrate new multi-trace seismic attributes (volumetric curvature, in particular) for improved imaging of karst-modified reservoirs, (2) to develop attribute-based, cost-effective workflows to better characterize karst-modified carbonate reservoirs and fracture systems, and (3) to improve accuracy and predictiveness of resulting geomodels and reservoir simulations. In order to develop our workflows and validate our techniques, we conducted integrated studies of five karst-modified reservoirs in west Texas, Colorado, and Kansas. Our studies show that 3-D seismic volumetric curvature attributes have the ability to re-veal previously unknown features or provide enhanced visibility of karst and fracture features compared with other seismic analysis methods. Using these attributes, we recognize collapse features, solution-enlarged fractures, and geomorphologies that appear to be related to mature, cockpit landscapes. In four of our reservoir studies, volumetric curvature attributes appear to delineate reservoir compartment boundaries that impact production. The presence of these compartment boundaries was corroborated by reservoir simulations in two of the study areas. Based on our study results, we conclude that volumetric curvature attributes are valuable tools for mapping compartment boundaries in fracture- and karst-modified reservoirs, and we propose a best practices workflow for incorporating these attributes into reservoir characterization. When properly calibrated with geological and production data, these attributes can be used to predict the locations and sizes of undrained reservoir compartments. Technology transfer of our project work has been accomplished through presentations at professional society meetings, peer-reviewed publications

  2. The trade-off between safety and efficiency in hydraulic architecture in 31 woody species in a karst area.

    Science.gov (United States)

    Fan, Da-Yong; Jie, Sheng-Lin; Liu, Chang-Cheng; Zhang, Xiang-Ying; Xu, Xin-Wu; Zhang, Shou-Ren; Xie, Zong-Qiang

    2011-08-01

    Karst topography is a special landscape shaped by the dissolution of one or more layers of soluble bedrock, usually carbonate rock such as limestone or dolomite. Due to subterranean drainage, overland flow, extraction of water by plants and evapotranspiration, there may be very limited surface water. The hydraulic architecture that plants use to adapt to karst topography is very interesting, but few systematic reports exist. The karst area in southwestern China is unique when compared with other karst areas at similar latitudes, because of its abundant precipitation, with rainfall concentrated in the growing season. In theory, resistance to water-stress-induced cavitation via air seeding should be accompanied by decreased pore hydraulic conductivity and stem hydraulic conductivity. However, evidence for such trade-offs across species is ambiguous. We measured the hydraulic structure and foliar stable carbon isotope ratios of 31 karst woody plants at three locations in Guizhou Province, China, to evaluate the functional coordination between resistance to cavitation and specific conductivity. We also applied phylogenetically independent contrast (PIC) analysis in situations where the inter-species correlations of functional traits may be biased on the potential similarity of closely related species. The average xylem tension measurement, at which 50% of hydraulic conductivity of the plants was lost (Ψ(50)), was only -1.27 MPa. Stem Ψ(50) was positively associated with specific conductance (K(s)) (P sapwood area:leaf area ratio) was negatively correlated with K(s) in both the traditional cross-species correlation and the corresponding PIC correlations (P < 0.01). The characteristics of hydraulic architecture measured in this study showed that karst plants in China are not highly cavitation-resistant species. This study also supports the idea that there may not be an evolutionary trade-off between resistance to cavitation and specific conductivity in woody

  3. Hydrological connectivity in the karst critical zone: an integrated approach

    Science.gov (United States)

    Chen, X.; Zhang, Z.; Soulsby, C.; Cheng, Q.; Binley, A. M.; Tao, M.

    2017-12-01

    Spatial heterogeneity in the subsurface is high, evidenced by specific landform features (sinkholes, caves etc.) and resulting in high variability of hydrological processes in space and time. This includes complex exchange of various flow sources (e.g. hillslope springs and depression aquifers) and fast conduit flow and slow fracture flow. In this paper we integrate various "state-of-the-art" methods to understand the structure and function of this understudied critical zone environment. Geophysical, hydrometric and hydrogeochemical tools are used to characterize the hydrological connectivity of the cockpit karst critical zone in a small catchment of Chenqi, Guizhou province, China. Geophysical surveys, using electrical resistivity tomography (ERT), identified the complex conduit networks that link flows between hillslopes and depressions. Statistical time series analysis of water tables and discharge responses at hillslope springs and in depression wells and underground channels showed different threshold responses of hillslope and depression flows. This reflected the differing relative contribution of fast and slow flow paths during rainfall events of varying magnitude in the hillslope epikarst and depression aquifer in dry and wet periods. This showed that the hillslope epikarst receives a high proportion of rainfall recharge and is thus a main water resource in the catchment during the drought period. In contrast, the depression aquifer receives fast, concentrated hillslope flows during large rainfall events during the wet period, resulting in the filling of depression conduits and frequent flooding. Hydrological tracer studies using water temperatures and stable water isotopes (δD and δ18O) corroborated this and provided quantitative information of the mixing proportions of various flow sources and insights into water travel times. This revealed how higher contributions of event "new" water (from hillslope springs and depression conduits displaces "old" pre

  4. Interesting Interest Points

    DEFF Research Database (Denmark)

    Aanæs, Henrik; Dahl, Anders Lindbjerg; Pedersen, Kim Steenstrup

    2012-01-01

    on spatial invariance of interest points under changing acquisition parameters by measuring the spatial recall rate. The scope of this paper is to investigate the performance of a number of existing well-established interest point detection methods. Automatic performance evaluation of interest points is hard......Not all interest points are equally interesting. The most valuable interest points lead to optimal performance of the computer vision method in which they are employed. But a measure of this kind will be dependent on the chosen vision application. We propose a more general performance measure based...... position. The LED illumination provides the option for artificially relighting the scene from a range of light directions. This data set has given us the ability to systematically evaluate the performance of a number of interest point detectors. The highlights of the conclusions are that the fixed scale...

  5. Palaeo-karst of diwa type and metallogenesis in Guangxi

    International Nuclear Information System (INIS)

    Liu Lijun; Shi Jingkun; Wang Qinghe.

    1989-01-01

    Two palaeo-karstification periods, the preliminary mobilization period and the climax-mobilization period of diwa development have been recognized. The subsurface caverns formed in these two periods were separately filled with T 3 -J 3 , K-E accumulation materials and karst Palaeokarst sedimentary rock subsequently transformed into the fossil karst-palaeo-karst sedimentary bodies which are not currently carried by modern ground water circulation. During the preliminary mobilization period of diwa development, karstification was intimately associated with Cu, Zn, Mo, Ag, Sb, Au and U mineralization, thus resulting in the formation of palaeo-karst deposit. It is supposed that ore materials were derived from the perexisting ore source stratum, bodies or mineralization. They were suffered from epigenetic weathering and leaching, were transported into ancient underground caves and were concentrated to form deposits by bacterial action. This type of the deposit possesses great potential in prospecting. The genetic model can be briefly summarized as follows: the pre-existing ore source → the diwa → superimposed palaeo-karst depression → the karst sedimentary bodies of the preliminary-mobilization period of diwa development → the anomalies of sulphophile element and radioactivity → the middle to bottom part of palaeo-karst sedimentary body along the direction of palaeo-karst → ore bodies

  6. Adaptations of indigenous bacteria to fuel contamination in karst aquifers in south-central Kentucky

    Science.gov (United States)

    Byl, Thomas D.; Metge, David W.; Agymang, Daniel T.; Bradley, Michael W.; Hileman, Gregg; Harvey, Ronald W.

    2014-01-01

    The karst aquifer systems in southern Kentucky can be dynamic and quick to change. Microorganisms that live in these unpredictable aquifers are constantly faced with environmental changes. Their survival depends upon adaptations to changes in water chemistry, taking advantage of positive stimuli and avoiding negative environmental conditions. The U.S. Geological Survey conducted a study in 2001 to determine the capability of bacteria to adapt in two distinct regions of water quality in a karst aquifer, an area of clean, oxygenated groundwater and an area where the groundwater was oxygen depleted and contaminated by jet fuel. Water samples containing bacteria were collected from one clean well and two jet fuel contaminated wells in a conduit-dominated karst aquifer. Bacterial concentrations, enumerated through direct count, ranged from 500,000 to 2.7 million bacteria per mL in the clean portion of the aquifer, and 200,000 to 3.2 million bacteria per mL in the contaminated portion of the aquifer over a twelve month period. Bacteria from the clean well ranged in size from 0.2 to 2.5 mm, whereas bacteria from one fuel-contaminated well were generally larger, ranging in size from 0.2 to 3.9 mm. Also, bacteria collected from the clean well had a higher density and, consequently, were more inclined to sink than bacteria collected from contaminated wells. Bacteria collected from the clean portion of the karst aquifer were predominantly (,95%) Gram-negative and more likely to have flagella present than bacteria collected from the contaminated wells, which included a substantial fraction (,30%) of Gram-positive varieties. The ability of the bacteria from the clean portion of the karst aquifer to biodegrade benzene and toluene was studied under aerobic and anaerobic conditions in laboratory microcosms. The rate of fuel biodegradation in laboratory studies was approximately 50 times faster under aerobic conditions as compared to anaerobic, sulfur-reducing conditions. The

  7. Verification of the karst flow model under laboratory controlled conditions

    Science.gov (United States)

    Gotovac, Hrvoje; Andric, Ivo; Malenica, Luka; Srzic, Veljko

    2016-04-01

    Karst aquifers are very important groundwater resources around the world as well as in coastal part of Croatia. They consist of extremely complex structure defining by slow and laminar porous medium and small fissures and usually fast turbulent conduits/karst channels. Except simple lumped hydrological models that ignore high karst heterogeneity, full hydraulic (distributive) models have been developed exclusively by conventional finite element and finite volume elements considering complete karst heterogeneity structure that improves our understanding of complex processes in karst. Groundwater flow modeling in complex karst aquifers are faced by many difficulties such as a lack of heterogeneity knowledge (especially conduits), resolution of different spatial/temporal scales, connectivity between matrix and conduits, setting of appropriate boundary conditions and many others. Particular problem of karst flow modeling is verification of distributive models under real aquifer conditions due to lack of above-mentioned information. Therefore, we will show here possibility to verify karst flow models under the laboratory controlled conditions. Special 3-D karst flow model (5.6*2.6*2 m) consists of concrete construction, rainfall platform, 74 piezometers, 2 reservoirs and other supply equipment. Model is filled by fine sand (3-D porous matrix) and drainage plastic pipes (1-D conduits). This model enables knowledge of full heterogeneity structure including position of different sand layers as well as conduits location and geometry. Moreover, we know geometry of conduits perforation that enable analysis of interaction between matrix and conduits. In addition, pressure and precipitation distribution and discharge flow rates from both phases can be measured very accurately. These possibilities are not present in real sites what this model makes much more useful for karst flow modeling. Many experiments were performed under different controlled conditions such as different

  8. Hazard connected to railway tunnel construction in karstic area: applied geomorphological and hydrogeological surveys

    Directory of Open Access Journals (Sweden)

    G. Casagrande

    2005-01-01

    Full Text Available In a mature karstic system, the realisation of galleries using the methodology of railway tunnel boring machine (TBM involves particular problems due to the high risk of interference with groundwater (often subject to remarkable level variations and with cavities and/or thick fill deposits. In order to define groundwater features it is necessary to investigate both hydrodynamic and karstification. To define and quantify the karst phenomenon in the epikarst of the Trieste Karst (Italy, an applied geomorphological approach has been experimented with surface and cavity surveys. The surface surveys have contributed to determining the potential karst versus the different outcropping lithologies and to define the structural setting of the rocky mass also through the realisation of geostructural stations and the survey of the main lines thanks to photo-interpretation. Moreover, all the dolines and the cavities present in the area interested by the gallery have been studied by analysing the probable extension of caves and/or of the secondary fill deposits and by evaluating the different genetic models. In an area 900m large and 27km long, which has been studied because of the underground karst, there are 41 dolines having diameters superior to 100m and 93 dolines whose diameters range between 100 and 50m; the dolines whose diameters are inferior to 50m are 282. The entrances of known and registered cavities in the cadastre records are 520. The hypogeal surveys have shown 5 typologies in which it has been possible to group all the cavities present in a hypothetical intersection with the excavation. The comparison between surface and hypogeal structural data and the direction of development of cavities has allowed for the definition of highly karstified discontinuity families, thus having a higher risk. The comparison of the collected data has enabled to identify the lithologies and areas having major risk and thus to quantify the probability of

  9. Hazard connected to railway tunnel construction in karstic area: applied geomorphological and hydrogeological surveys

    Science.gov (United States)

    Casagrande, G.; Cucchi, F.; Zini, L.

    2005-02-01

    In a mature karstic system, the realisation of galleries using the methodology of railway tunnel boring machine (TBM) involves particular problems due to the high risk of interference with groundwater (often subject to remarkable level variations) and with cavities and/or thick fill deposits. In order to define groundwater features it is necessary to investigate both hydrodynamic and karstification. To define and quantify the karst phenomenon in the epikarst of the Trieste Karst (Italy), an applied geomorphological approach has been experimented with surface and cavity surveys. The surface surveys have contributed to determining the potential karst versus the different outcropping lithologies and to define the structural setting of the rocky mass also through the realisation of geostructural stations and the survey of the main lines thanks to photo-interpretation. Moreover, all the dolines and the cavities present in the area interested by the gallery have been studied by analysing the probable extension of caves and/or of the secondary fill deposits and by evaluating the different genetic models. In an area 900m large and 27km long, which has been studied because of the underground karst, there are 41 dolines having diameters superior to 100m and 93 dolines whose diameters range between 100 and 50m; the dolines whose diameters are inferior to 50m are 282. The entrances of known and registered cavities in the cadastre records are 520. The hypogeal surveys have shown 5 typologies in which it has been possible to group all the cavities present in a hypothetical intersection with the excavation. The comparison between surface and hypogeal structural data and the direction of development of cavities has allowed for the definition of highly karstified discontinuity families, thus having a higher risk. The comparison of the collected data has enabled to identify the lithologies and areas having major risk and thus to quantify the probability of intersection with the

  10. Determination of karst collapse intensity indicator in area of nuclear power plant construction using incomplete data

    International Nuclear Information System (INIS)

    Sharapov, R

    2014-01-01

    The paper deals with the definition of karst collapse intensity. The technique for determining the intensity of karst formation and collapse on the basis of calculation and probabilistic method is given. Karst collapse formation is affected by a great variety of natural and anthropogenic factors. Each factor can vary quite widely. The paper describes a technique for determining karst collapse intensity from incomplete data. It uses karst processes monitoring data in the area and monitoring data of areas with similar values of the most significant factors leading to the karst collapses. The method used for determination of karst collapse intensity indicator in area of Nizhny Novgorod nuclear power plant construction

  11. Effectiveness of airborne multispectral thermal data for karst groundwater resources recognition in coastal areas

    Science.gov (United States)

    Pignatti, Stefano; Fusilli, Lorenzo; Palombo, Angelo; Santini, Federico; Pascucci, Simone

    2013-04-01

    Currently the detection, use and management of groundwater in karst regions can be considered one of the most significant procedures for solving water scarcity problems during periods of low rainfall this because groundwater resources from karst aquifers play a key role in the water supply in karst areas worldwide [1]. In many countries of the Mediterranean area, where karst is widespread, groundwater resources are still underexploited, while surface waters are generally preferred [2]. Furthermore, carbonate aquifers constitute a crucial thermal water resource outside of volcanic areas, even if there is no detailed and reliable global assessment of thermal water resources. The composite hydrogeological characteristics of karst, particularly directions and zones of groundwater distribution, are not up till now adequately explained [3]. In view of the abovementioned reasons the present study aims at analyzing the detection capability of high spatial resolution thermal remote sensing of karst water resources in coastal areas in order to get useful information on the karst springs flow and on different characteristics of these environments. To this purpose MIVIS [4, 5] and TASI-600 [6] airborne multispectral thermal imagery (see sensors' characteristics in Table 1) acquired on two coastal areas of the Mediterranean area interested by karst activity, one located in Montenegro and one in Italy, were used. One study area is located in the Kotor Bay, a winding bay on the Adriatic Sea surrounded by high mountains in south-western Montenegro and characterized by many subaerial and submarine coastal springs related to deep karstic channels. The other study area is located in Santa Cesarea (Italy), encompassing coastal cold springs, the main local source of high quality water, and also a noticeable thermal groundwater outflow. The proposed study shows the preliminary results of the two airborne deployments on these areas. The preprocessing of the multispectral thermal imagery

  12. Factors that Determine Academic Versus Private Practice Career Interest in Radiation Oncology Residents in the United States: Results of a Nationwide Survey

    International Nuclear Information System (INIS)

    Chang, Daniel T.; Shaffer, Jenny L.; Haffty, Bruce G.; Wilson, Lynn D.

    2013-01-01

    Purpose: To determine what factors US radiation oncology residents consider when choosing academic or nonacademic careers. Methods and Materials: A 20-question online survey was developed and sent to all US radiation oncology residents to assess factors that influence their career interest. Residents were asked to rate their interest in academics (A) versus private practice (PP) on a 0 (strong interest in A) to 100 (strong interest in PP) scale. Responses were classified as A (0-30), undecided (40-60), and PP (70-100). Residents were also asked to rank 10 factors that most strongly influenced their career interest. Results: Three hundred thirty-one responses were collected, of which 264 were complete and form the basis for this analysis. Factors that correlated with interest in A included having a PhD (P=.018), postgraduate year level (P=.0006), research elective time (P=.0003), obtaining grant funding during residency (P=.012), and number of publications before residency (P=.0001), but not number of abstracts accepted in the past year (P=.65) or publications during residency (P=.67). The 3 most influential factors for residents interested in A were: (1) baseline interest before residency; (2) academic role models; and (3) research opportunities during residency. The 3 most influential factors for residents interested in PP were: (1) baseline interest before residency; (2) academic role models; and (3) academic pressure and obligations. Conclusions: Interest in A correlated with postgraduate year level, degree, and research time during residency. Publications before but not during residency correlated with academic interest, and baseline interest was the most influential factor. These data can be used by residency program directors to better understand what influences residents' career interest

  13. Conflict-of-interest disclosure at medical journals in Japan: a nationwide survey of the practices of journal secretariats.

    Science.gov (United States)

    Kojima, Takako; Green, Joseph; Barron, J Patrick

    2015-08-26

    Medical journals in Japan generally have appropriate policies regarding disclosure of conflicts of interest (COI). However, COI management depends on the staff members of each journal's editorial secretariat. This study's objectives were to find out (A) whether COI disclosure and the journal's role in it are clearly understood by the journal's secretariat staff, (B) how much experience the editorial secretariat has in actually handling issues related to disclosure and (C) what kind of help or support they need. In January 2014, questionnaires were sent to the editorial secretariats of journal-publishing societies belonging to the Japanese Association of Medical Sciences (JAMS). The response rate was 100%, and the respondents represented 121 journals published by the 118 JAMS member societies (at the time of the survey). Information was collected on the history of COI policies and on how those policies were implemented. At the end of the questionnaire, there was an open-ended call for comments. Compulsory COI disclosure began between 2010 and 2013 for 60.3% of the journals (73/121). Handling of COI issues was not uniform: 17.4% (21/121) of respondents do not pursue cases of dubious disclosure, and 47.9% (58/121) do not require COI disclosures from editorial board members. Very few of the editorial secretariats had clearly-stated consequences for violations of COI-disclosure policy (33/121, 27.3%), and only 28.9% offered COI education (35/121). Respondents' comments indicated that uniform, easily-searchable guidance regarding COI policies and implementation would be welcome. Although commitment is widespread, policy implementation is inconsistent and COI experience is lacking. Clear, easy-to-use guidelines are desired by many societies. The JAMS is to be commended for supporting this country-wide investigation; other countries and regions are encouraged to perform similar investigations to respond to needs regarding COI management. Published by the BMJ Publishing

  14. Karst risk assessment for engineering in Nizhny Novgorod region, Russia

    Directory of Open Access Journals (Sweden)

    Tolmachev Vladimir

    2013-01-01

    Full Text Available Federal Standards of the Russian include the requirement of mandatory assessment of the risks induced by natural processes in order to make sure their values do not exceed acceptable limits. To meet the requirement a number of karst risk assessment methods have been developed for the regions of the country where the most significant hazard is presented by karst sinkholes. For this particular application karst risk is understood as specific probability of sinkhole development on a unit area per a unit time span with account of probable economic, social and environmental components of damage. The probability of sinkhole development is evaluated by specialists in engineering karstology and designers. They make use of the acceptable data on the environmental conditions and apply stochastic laws of sinkhole development in time and space, alongside with focusing on all other relevant specificity of the building or facility to be built. Acceptable limits of karst risks should be specified by a multidisciplinary team including designers, lawyers, economists, insurers, environmentalists, engineering karstologists and other specialists on the basis of their expert knowledge. It has been demonstrated that a ratio between predicted and acceptable karst risk values can serve a practically meaningful karst risk level indicator for the purposes of building on karst. This ratio can be used with a rather high degree of objectiveness to develop a programme of antikarst activities during both facilities construction and operation.

  15. Spatial Distribution of Nitrogen on Grazed Karst Landscapes

    Directory of Open Access Journals (Sweden)

    Douglas G. Boyer

    2001-01-01

    Full Text Available The impact on water quality by agricultural activity in karst terrain is an important consideration for resource management within the Appalachian region. Karst areas comprise about 18% of the region’s land area. An estimated one-third of the region’s farms, cattle, and agricultural market value are located on karst terrain. Mean nitrate concentrations in several karst springs in southeastern West Virginia exhibit a strong linear relationship with the percentage of agriculture land cover. Development of best management practices for efficient nitrogen (N use and reduction of outflow of N to water from karst areas requires knowledge about N dynamics on those landscapes. Water extractable NO3-N and NH4-N were measured along transects at four soil depths in two grazed sinkholes and one wooded sinkhole. Distribution of soil NO3-N and NH4-N were related to frequency of animal presence and to topographic and hydrologic redistribution of soil and fecal matter in the grazed sinkholes. Karst pastures are characterized by under drainage and funneling of water and contaminants to the shallow aquifer. Control of NO3-N leaching from karst pasture may depend on management strategies that change livestock grazing behavior in sinkholes and reduce the opportunity for water and contaminants to quickly reach sinkhole drains.

  16. Improved 2-D resistivity imaging of features in covered karst terrain with arrays of implanted electrodes

    Science.gov (United States)

    Kiflu, H. G.; Kruse, S. E.; Harro, D.; Loke, M. H.; Wilkinson, P. B.

    2013-12-01

    Electrical resistivity tomography is commonly used to identify geologic features associated with sinkhole formation. In covered karst terrain, however, it can be difficult to resolve the depth to top of limestone with this method. This is due to the fact that array lengths, and hence depth of resolution, are often limited by residential or commercial lot dimensions in urban environments. Furthermore, the sediments mantling the limestone are often clay-rich and highly conductive. The resistivity method has limited sensitivity to resistive zones beneath conductive zones. This sensitivity can be improved significantly with electrodes implanted at depth in the cover sediments near the top of limestone. An array of deep electrodes is installed with direct push technology in the karst cover. When combined with a surface array in which each surface electrode is underlain by a deep electrode, the array geometry is similar to a borehole array turned on its side. This method, called the Multi-Electrode Resistivity Implant Technique (MERIT), offers the promise of significantly improved resolution of epikarst and cover collapse development zones in the overlying sediment, the limestone or at the sediment-bedrock interface in heterogeneous karst environments. With a non-traditional array design, the question of optimal array geometries arises. Optimizing array geometries is complicated by the fact that many plausible 4-electrode readings will produce negative apparent resistivity values, even in homogeneous terrain. Negative apparent resistivities cannot be used in inversions based on the logarithm of the apparent resistivity. New algorithms for seeking optimal array geometries have been developed by modifying the 'Compare R' method of Wilkinson and Loke. The optimized arrays show significantly improved resolution over basic arrays adapted from traditional 2D surface geometries. Several MERIT case study surveys have been conducted in covered karst in west-central Florida, with

  17. Karst groundwater: a challenge for new resources

    Science.gov (United States)

    Bakalowicz, Michel

    2005-03-01

    Karst aquifers have complex and original characteristics which make them very different from other aquifers: high heterogeneity created and organised by groundwater flow; large voids, high flow velocities up to several hundreds of m/h, high flow rate springs up to some tens of m3/s. Different conceptual models, known from the literature, attempt to take into account all these particularities. The study methods used in classical hydrogeology—bore hole, pumping test and distributed models—are generally invalid and unsuccessful in karst aquifers, because the results cannot be extended to the whole aquifer nor to some parts, as is done in non-karst aquifers. Presently, karst hydrogeologists use a specific investigation methodology (described here), which is comparable to that used in surface hydrology. Important points remain unsolved. Some of them are related to fundamental aspects suc h as the void structure - only a conduit network, or a conduit network plus a porous matrix -, the functioning - threshold effects and non-linearities -, the modeling of the functioning - double or triple porosity, or viscous flow in conduits - and of karst genesis. Some other points deal with practical aspects, such as the assessment of aquifer storage capacity or vulnerability, or the prediction of the location of highly productive zones. Los acuíferos kársticos tienen características originales y complejas que los hacen muy diferentes de otros acuíferos: alta heterogeneidad creada y organizada por el flujo de agua subterránea, espacios grandes, velocidades altas de flujo de hasta varios cientos de m/h, manantiales con ritmo alto de flujo de hasta algunas decenas de m3/s. Diferentes modelos conceptuales que se conocen en la literatura tratan de tomar en cuenta todas estas particularidades. Los métodos de estudio usados en hidrogeología clásica- pozos, pruebas de bombeo y modelos distribuidos- son generalmente inválidos y no exitosos en acuíferos kársticos, debido a que

  18. Gypsum karst in Italy: a review

    Science.gov (United States)

    De Waele, Jo; Chiarini, Veronica; Columbu, Andrea; D'Angeli, Ilenia M.; Madonia, Giuliana; Parise, Mario; Piccini, Leonardo; Vattano, Marco; Vigna, Bartolomeo; Zini, Luca; Forti, Paolo

    2016-04-01

    Although outcropping only rarely in Italy, gypsum karst has been described in detail since the early XXth century (Marinelli, 1917). Gypsum caves are now known from almost all Italian regions (Madonia & Forti, 2003), but are mainly localised along the northern border of the Apennine chain (Emilia Romagna and Marche regions), Calabria, and Sicily, where the major outcrops occur. Recently, important caves have also been discovered in the underground gypsum quarries in Piedmont (Vigna et al., 2010). During the late 80s and 90s several multidisciplinary studies have been carried out in many gypsum areas. All this work converged into a comprehensive overview in 2003 (Madonia & Forti, 2003). Further detailed studies focused on the gypsum areas of Emilia Romagna (Chiesi et al., 2010; Forti & Lucci, 2010; Demaria et al., 2012; De Waele & Pasini, 2013; Ercolani et al., 2013; Columbu et al., 2015; Lucci & Piastra, 2015; Tedeschi et al., 2015) and of Sicily (Madonia & Vattano, 2011). Sinkholes related to Permo-Triassic gypsum have been studied in Friuli Venezia Giulia (Zini et al., 2015). This presentation will review the state of the art regarding different aspects of evaporite karst in Italy focusing on the main new results. References Chiesi M., et al. (2010) - Origin and evolution of a salty gypsum/anhydrite karst spring: the case of Poiano (Northern Apennines, Italy). Hydrogeology Journal, 18, pp. 1111-1124. Columbu A. et al. (2015) - Gypsum caves as indicators of climate-driven river incision and aggradation in a rapidly uplifting region. Geology, 43(6), 539-542. Demaria D. et al. (Eds.) (2012), Le Grotte Bolognesi, GSB-USB, 431 p. De Waele J., Pasini G. (2013) - Intra-messinian gypsum palaeokarst in the northern Apennines and its palaeogeographic implications. Terra Nova 25, pp. 199-205. Ercolani M., et al. (Eds.) (2013), I Gessi e la Cave i Monte Tondo. Studio multidisciplinare di un'area carsica nella Vena del Gesso Romagnola. Memorie Ist. It. Spel. II(26), 559 p

  19. Main karst and caves of Switzerland; El karst y las cuevas mas importantes de Suiza

    Energy Technology Data Exchange (ETDEWEB)

    Jeannin, P. Y.

    2016-07-01

    This paper presents an overview of the main karst areas and cave systems in Switzerland. The first part encloses descriptions of the main geological units that hold karst and caves in the country and summarizes a brief history of research and protection of the cave environments. The second part presents three regions enclosing large cave systems. Two regions in the Alps enclose some of the largest limestone caves in Europe: Siebenhengste (Siebenhengste cave system with ∼160 km and Barenschacht with 70 km) and Bodmeren-Silberen (Holloch cave system with 200 km and Silberen System with 39 km). These systems are also among the deepest with depths ranging between 880 and 1340 m. The third example is from the Jura Mountains (northern Switzerland). (Author)

  20. Surface-water and karst groundwater interactions and streamflow-response simulations of the karst-influenced upper Lost River watershed, Orange County, Indiana

    Science.gov (United States)

    Bayless, E. Randall; Cinotto, Peter J.; Ulery, Randy L.; Taylor, Charles J.; McCombs, Gregory K.; Kim, Moon H.; Nelson, Hugh L.

    2014-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (USACE) and the Indiana Office of Community and Rural Affairs (OCRA), conducted a study of the upper Lost River watershed in Orange County, Indiana, from 2012 to 2013. Streamflow and groundwater data were collected at 10 data-collection sites from at least October 2012 until April 2013, and a preliminary Water Availability Tool for Environmental Resources (WATER)-TOPMODEL based hydrologic model was created to increase understanding of the complex, karstic hydraulic and hydrologic system present in the upper Lost River watershed, Orange County, Ind. Statistical assessment of the optimized hydrologic-model results were promising and returned correlation coefficients for simulated and measured stream discharge of 0.58 and 0.60 and Nash-Sutcliffe efficiency values of 0.56 and 0.39 for USGS streamflow-gaging stations 03373530 (Lost River near Leipsic, Ind.), and 03373560 (Lost River near Prospect, Ind.), respectively. Additional information to refine drainage divides is needed before applying the model to the entire karst region of south-central Indiana. Surface-water and groundwater data were used to tentatively quantify the complex hydrologic processes taking place within the watershed and provide increased understanding for future modeling and management applications. The data indicate that during wet-weather periods and after certain intense storms, the hydraulic capacity of swallow holes and subsurface conduits is overwhelmed with excess water that flows onto the surface in dry-bed relic stream channels and karst paleovalleys. Analysis of discharge data collected at USGS streamflow-gaging station 03373550 (Orangeville Rise, at Orangeville, Ind.), and other ancillary data-collection sites in the watershed, indicate that a bounding condition is likely present, and drainage from the underlying karst conduit system is potentially limited to near 200 cubic feet per second. This

  1. Numerical Study of Groundwater Flow and Salinity Distribution Cycling Controlled by Seawater/Freshwater Interaction in Karst Aquifer Using SEAWAT

    Science.gov (United States)

    Xu, Z.; Hu, B.

    2017-12-01

    The interest to predict seawater intrusion and salinity distribution in Woodville Karst Plain (WKP) has increased due to the huge challenge on quality of drinkable water and serious environmental problems. Seawater intrudes into the conduit system from submarine karst caves at Spring Creek Spring due to density difference and sea level rising, nowadays the low salinity has been detected at Wakulla Spring which is 18 km from coastal line. The groundwater discharge at two major springs and salinity distribution in this area is controlled by the seawater/freshwater interaction under different rainfall conditions: during low rainfall periods, seawater flow into the submarine spring through karst windows, then the salinity rising at the submarine spring leads to seawater further intrudes into conduit system; during high rainfall periods, seawater is pushed out by fresh water discharge at submarine spring. The previous numerical studies of WKP mainly focused on the density independent transport modeling and seawater/freshwater discharge at major karst springs, in this study, a SEAWAT model has been developed to fully investigate the salinity distribution in the WKP under repeating phases of low rainfall and high rainfall periods, the conduit system was simulated as porous media with high conductivity and porosity. The precipitation, salinity and discharge at springs were used to calibrate the model. The results showed that the salinity distribution in porous media and conduit system is controlled by the rainfall change, in general, the salinity distribution inland under low rainfall conditions is much higher and wider than the high rainfall conditions. The results propose a prediction on the environmental problem caused by seawater intrusion in karst coastal aquifer, in addition, provide a visual and scientific basis for future groundwater remediation.

  2. Factors influencing the career interest of medical graduates in obstetrics and gynaecology in Hong Kong: a cross-sectional questionnaire survey.

    Science.gov (United States)

    Lam, Christy Y Y; Cheung, Charleen S Y; Hui, Annie S Y

    2016-04-01

    The trend of declining interest of medical graduates in pursuing obstetrics and gynaecology as a career has been observed in many overseas studies. This study aimed to evaluate the career interest of the most recent medical graduates in Hong Kong, especially their level of interest in obstetrics and gynaecology, and to identify key influential factors for career choice and career interest in obstetrics and gynaecology. All medical graduates from the Chinese University of Hong Kong and the University of Hong Kong who attended the pre-internship lectures in June 2015 were invited to participate in this cross-sectional questionnaire survey. The main outcome measures were the level of career interest in obstetrics and gynaecology, the first three choices of specialty as a career, key influential factors for career choice, and key influential factors for career interest in obstetrics and gynaecology. Overall, 73.7% of 323 new medical graduates participated in the study and 233 questionnaires were analysed. The median score (out of 10) for the level of career interest in obstetrics and gynaecology was 3. There were 37 (16.2%) participants in whom obstetrics and gynaecology was among their first three choices, of whom 29 (78.4%) were female. Obstetrics and gynaecology ranked as the eighth most popular career choice. By factor analysis, the strongest key influential factor for career interest in obstetrics and gynaecology was clerkship experience (variance explained 28.9%) and the strongest key influential factor for career choice was working style (variance explained 26.4%). The study confirmed a low level of career interest in obstetrics and gynaecology among medical graduates and a decreasing popularity of the specialty as a career choice. The three key influential factors for career interest in obstetrics and gynaecology and career choice were working style, clerkship experience, and career prospects.

  3. Long distance seawater intrusion through a karst conduit network in the Woodville Karst Plain, Florida

    Science.gov (United States)

    Xu, Zexuan; Bassett, Seth Willis; Hu, Bill; Dyer, Scott Barrett

    2016-08-01

    Five periods of increased electrical conductivity have been found in the karst conduits supplying one of the largest first magnitude springs in Florida with water. Numerous well-developed conduit networks are distributed in the Woodville Karst Plain (WKP), Florida and connected to the Gulf of Mexico. A composite analysis of precipitation and electrical conductivity data provides strong evidence that the increases in conductivity are directly tied to seawater intrusion moving inland and traveling 11 miles against the prevailing regional hydraulic gradient from from Spring Creek Spring Complex (SCSC), a group of submarine springs at the Gulf Coast. A geochemical analysis of samples from the spring vent rules out anthropogenic contamination and upwelling regional recharge from the deep aquifer as sources of the rising conductivity. The interpretation is supported by the conceptual model established by prior researchers working to characterize the study area. This paper documents the first and longest case of seawater intrusion in the WKP, and also indicates significant possibility of seawater contamination through subsurface conduit networks in a coastal karst aquifer.

  4. Public attitudes towards preventive genomics and personal interest in genetic testing to prevent disease: a survey study

    NARCIS (Netherlands)

    Vermeulen, E.; Henneman, L.; van El, C.G.; Cornel, M.C.

    2014-01-01

    Background: Genetic testing and family history assessment can be used as an aid in the prevention of common chronic diseases. The aim of this study was to determine public attitudes and interests towards offering genetic testing and family history-based risk assessment for common chronic disease

  5. International symposium and field seminar on karst waters and environmental impacts. Abstracts

    International Nuclear Information System (INIS)

    Gunay, G.; Tezcan, L.; Atilla, A.O.

    1995-01-01

    The international symposium and field seminar on karst waters and environmental impacts was held on 10-20 September 1995 in Beldibi,Antalya, Turkey. The specialists discussed COST Action 65, Environmental Impact sand Legal Aspects, Engineering and Environmental Impacts of Karst, Research Methods, Tracing Techniques, Hydro chemistry, Environmental Isotopes in Karst, Transport Processing, Modeling and Flow Systems, Karst Morphology and Paleoenvironment, Regional Karst Systems, James F. Quinlay Pollution Control and Karst Water Protection Session and Hydrology. Almost 140 papers were presented in the meeting

  6. International symposium and field seminar on karst waters and environmental impacts. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Gunay, G; Tezcan, L; Atilla, A O [comps.

    1996-12-31

    The international symposium and field seminar on karst waters and environmental impacts was held on 10-20 September 1995 in Beldibi,Antalya, Turkey. The specialists discussed COST Action 65, Environmental Impact sand Legal Aspects, Engineering and Environmental Impacts of Karst, Research Methods, Tracing Techniques, Hydro chemistry, Environmental Isotopes in Karst, Transport Processing, Modeling and Flow Systems, Karst Morphology and Paleoenvironment, Regional Karst Systems, James F. Quinlay Pollution Control and Karst Water Protection Session and Hydrology. Almost 140 papers were presented in the meeting.

  7. Morphostructural Development of Gunungsewu Karst, Jawa Island

    Directory of Open Access Journals (Sweden)

    H. D. Tjia

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i2.157Gunungsewu Karst (also known as Sewu karst in the literature is synonymous with morphology of a carbonate terrain dominated by hills crowned by accordant-level tops that developed in a humid tropical environment by comparatively more rapid dissolution and denudation. In addition, the hills are sinoid to cone-shaped. Surface drainage is negligible compared to subsurface water flow. Abandoned channel segments and spatial arrangements of karst hills have been found to correspond with fracture patterns that are genetically associated with the regional compression direction of Jawa Island. Images derived from space platforms show many landform patterns that were neither known from ground-based nor from aerial photograph study. Landforms arranged in ring, multi-ring, spiral, polygonal, and long linear to serpentine patterns are common beside the expected depressions of dolines, poljes, and uvalas. The orientations of the long linear ridges appear to change systematically from those near the coast to those located inland. These linear ridges are interpreted as depositional fronts, most likely representing breaker zones. The youngest depositional ridge fronts, located nearest to the present shoreline, are parallel to the geological strike of Jawa Island. Toward the island’s interior, linear depositional fronts deviate in orientation by as much as 40o. This is now interpreted to have resulted from counterclockwise rotation of the Gunungsewu microplate since the late Middle Miocene. Similar CCW rotations are indicated by the paleomagnetic orientations of igneous rocks located farther east in the southern range of the island. Active tectonics is expressed in stage-wise net uplift of Gunungsewu whereas regional tilting appears negligible. Stacked and often paired river terraces (thus suggesting land uplift have been used to relatively date paleoarcheological finds. Very recent uplift on the coast show up in lazy-V limestone

  8. The role of karst in engineering and environmental geosciences

    Directory of Open Access Journals (Sweden)

    H. C. Ho

    2011-08-01

    Full Text Available Karst is a unique landform developed by soluble rock. It usually relates to the groundwater drainage system, and provides important water resources. Current researches indicate that karst is closely related to the Earth system and environmental protection, and it can also create potential natural hazards such as sinkhole flooding and land subsidence in urban area. Its relationship with hydrogeology has also been an important factor for studying water pollution and nutrient cycles in engineering geosciences and agricultural geology.

  9. Karst collapse in cities and mining areas, China

    International Nuclear Information System (INIS)

    Jian Chen

    1988-01-01

    Karst collapse is a dynamic geological phenomenon, in which the rock mass or deposits overlying the karstified zone subsides down along the karst cavity, resulting in a collapse pit or sinkhole. After discussing the typical examples of collapse emerging in the karst cities and mines in provinces and regions of South China, such as Guangdong, Guangxi, Hunan, Hubei, Zhejiang, Yunnan, Guizhou, and Jiangxi, it is considered that human activities of economy and production have become a major effect in causing karst collapse. Man-made collapses make 66.4 percent of the total, whereas natural ones 33.6 percent. Most of the collapses occurred to the area with soil overburden (96.7 percent), only a few in areas of bedrock overburden (3.3 percent). The karst collapses have a close relationship with the extent of karst development, the character and the thickness of overburden, and the dynamic condition of underground water. Collapse usually occurs in those parts of an area that are more intensely karstified, with soil thickness less than 5 m and a high amplitude of water table fluctuation. Many kinds of mechanical effects are caused by pumping or draining on the over-burden and destroying its equilibrium, leading to the collapse. These effects included the support loss and load-added effect, penetrating suffusion, gas explosion, water-hammer, suction pressure erosion, and liquefaction effects. The collapses are the result of varied comprehensive effects, particularly the support loss and load-added, and penetrating suffusion

  10. Conflict-of-interest disclosure at medical journals in Japan: a nationwide survey of the practices of journal secretariats

    OpenAIRE

    Kojima, Takako; Green, Joseph; Barron, J Patrick

    2015-01-01

    Objectives Medical journals in Japan generally have appropriate policies regarding disclosure of conflicts of interest (COI). However, COI management depends on the staff members of each journal's editorial secretariat. This study's objectives were to find out (A) whether COI disclosure and the journal's role in it are clearly understood by the journal’s secretariat staff, (B) how much experience the editorial secretariat has in actually handling issues related to disclosure and (C) what kind...

  11. Patient Smartphone Ownership and Interest in Mobile Apps to Monitor Symptoms of Mental Health Conditions: A Survey in Four Geographically Distinct Psychiatric Clinics.

    Science.gov (United States)

    Torous, John; Chan, Steven Richard; Yee-Marie Tan, Shih; Behrens, Jacob; Mathew, Ian; Conrad, Erich J; Hinton, Ladson; Yellowlees, Peter; Keshavan, Matcheri

    2014-01-01

    Despite growing interest in mobile mental health and utilization of smartphone technology to monitor psychiatric symptoms, there remains a lack of knowledge both regarding patient ownership of smartphones and their interest in using such to monitor their mental health. To provide data on psychiatric outpatients' prevalence of smartphone ownership and interest in using their smartphones to run applications to monitor their mental health. We surveyed 320 psychiatric outpatients from four clinics around the United States in order to capture a geographically and socioeconomically diverse patient population. These comprised a state clinic in Massachusetts (n=108), a county clinic in California (n=56), a hybrid public and private clinic in Louisiana (n=50), and a private/university clinic in Wisconsin (n=106). Smartphone ownership and interest in utilizing such to monitor mental health varied by both clinic type and age with overall ownership of 62.5% (200/320), which is slightly higher than the average United States' rate of ownership of 58% in January 2014. Overall patient interest in utilizing smartphones to monitor symptoms was 70.6% (226/320). These results suggest that psychiatric outpatients are interested in using their smartphones to monitor their mental health and own the smartphones capable of running mental healthcare related mobile applications.

  12. Study on Karst Information Identification of Qiandongnan Prefecture Based on RS and GIS Technology

    Science.gov (United States)

    Yao, M.; Zhou, G.; Wang, W.; Wu, Z.; Huang, Y.; Huang, X.

    2018-04-01

    Karst area is a pure natural resource base, at the same time, due to the special geological environment; there are droughts and floods alternating with frequent karst collapse, rocky desertification and other resource and environment problems, which seriously restrict the sustainable economic and social development in karst areas. Therefore, this paper identifies and studies the karst, and clarifies the distribution of karst. Provide basic data for the rational development of resources in the karst region and the governance of desertification. Due to the uniqueness of the karst landscape, it can't be directly recognized and extracted by computer in remote sensing images. Therefore, this paper uses the idea of "RS + DEM" to solve the above problems. this article is based on Landsat-5 TM imagery in 2010 and DEM data, proposes the methods to identify karst information research what is use of slope vector diagram, vegetation distribution map, distribution map of karst rocky desertification and other auxiliary data in combination with the signs for human-computer interaction interpretation, identification and extraction of peak forest, peaks cluster and isolated peaks, and further extraction of karst depression. Experiments show that this method achieves the "RS + DEM" mode through the reasonable combination of remote sensing images and DEM data. It not only effectively extracts karst areas covered with vegetation, but also quickly and accurately locks down the karst area and greatly improves the efficiency and precision of visual interpretation. The accurate interpretation rate of karst information in study area in this paper is 86.73 %.

  13. The karst network system of the Sierra de las Nieves (Malaga, Spain). An example of a high relief Mediterranean karst

    Energy Technology Data Exchange (ETDEWEB)

    Pardo-Iguzquiza, E.; Duran, J. J.; Robledo-Ardila, P.; Luque-Espinar, J. A.; Martos-Rosillo, S.; Guardiola-Albert, C.; Pedrera, A.

    2016-07-01

    The aim of this work is the stochastic simulation of a network of karst conduits in a high relief karst system. The simulation completes the existing cave mapping provided by speleological exploration and connects the recharge area with the discharge at the karst springs. The Sierra de las Nieves karst system is a high relief Mediterranean karst that has allowed the development of a system of large conduits and caves. The system follows the typical pattern of an alpine karst system with two characteristic zones where the development of the caves is different. The first zone, with a mean altitude of 1 750 m a.s.l., the Hoyas del Pilar and Torrecilla, is the area with highest altitude where recharge takes place and where the entrance potholes to the system are located. In this zone the cave system has a development mainly along the vertical (with 1,000 m of vertical development along a few hundreds of metres of horizontal development) with large shafts and narrow and steep meanders, until the local base level is reached at 700 m a.s.l. In the second zone, the system has a quasi-horizontal development with 300 m of altitude difference for 7 km in the horizontal until the base level of the system at the Rio Grande Spring (450 m a.s.l.). The transition between both zones is dominated by the presence of sumps where the conduits have vertical ondulations. The connectivity between the entrance and the resurgence has been demonstrated, in the past, by tracer tests. The system of super caves has been made possible because of the favourable conjunction of lithological, structural, geomorphological, hydrogeological and climatic factors. Geomorphic indices are introduced to describe the three-dimensional karst networks so the known network can be completed (i.e. simulated), taking into account statistical and probabilistic criteria. The simulated system can be used for the mathematical flow simulation of the karst system. (Author)

  14. Challenges of using electrical resistivity method to locate karst conduits-A field case in the Inner Bluegrass Region, Kentucky

    Science.gov (United States)

    Zhu, J.; Currens, J.C.; Dinger, J.S.

    2011-01-01

    Conduits serve as major pathways for groundwater flow in karst aquifers. Locating them from the surface, however, is one of the most challenging tasks in karst research. Geophysical methods are often deployed to help locate voids by mapping variations of physical properties of the subsurface. Conduits can cause significant contrasts of some physical properties that can be detected; other subsurface features such as water-bearing fractures often yield similar contrasts, which are difficult to distinguish from the effects of the conduits. This study used electrical resistivity method to search for an unmapped karst conduit that recharges Royal Spring in the Inner Bluegrass karst region, Kentucky, USA. Three types of resistivity techniques (surface 2D survey, quasi-3D survey, and time-lapse survey) were used to map and characterize resistivity anomalies. Some of the major anomalies were selected as drilling targets to verify the existence of the conduits. Drilling near an anomaly identified by an electrical resistivity profile resulted in successful penetration of a major water-filled conduit. The drilling results also suggest that, in this study area, low resistivity anomalies in general are associated with water-bearing features. However, differences in the anomaly signals between the water-filled conduit and other water-bearing features such as water-filled fracture zones were undistinguishable. The electrical resistivity method is useful in conduit detection by providing potential drilling targets. Knowledge of geology and hydrogeology about the site and professional judgment also played important roles in locating the major conduit. ?? 2011 Elsevier B.V.

  15. Hydrogeological characterization and environmental effects of the deteriorating urban karst groundwater in a karst trough valley: Nanshan, SW China

    Science.gov (United States)

    Jiang, Yongjun; Cao, Min; Yuan, Daoxian; Zhang, Yuanzhu; He, Qiufang

    2018-02-01

    The unique hydrogeology of karst makes the associated groundwater respond quickly to rainfall events and vulnerable to anthropogenic pollutions. In this study, high-frequency monitoring of spring discharge, temperature, electrical conductivity (EC) and pH, along with monthly hydrochemical and microbial analyses, was undertaken at the outlet of Laolondong karst underground river in Nanshan, southwestern China. The aim was to explore the environmental effects of the catchment's urban area on the karst groundwater resources. The monitoring data of a tracer test and the response of discharge to rainfall events demonstrate that conduits and narrow fissures coexist in the Laolongdong karst aquifer. The EC, Na+, Cl- and SO4 2- values (840 μS/cm, 33.7, 38.6 and 137.2 μg/L, respectively), along with high concentrations of fecal coliform bacteria, at the outlet indicate considerable urban pollution in this area. The contaminants sulfate and nitrate showed different relationships with discharge and EC in different stages of a rainfall event. This behavior provided information about aquifer structure and the influence of transport properties. Meanwhile, the hydrological processes of groundwater flow could be modified by urbanization and result in increasing magnitude of urban floods in the underground river. In addition, sulfuric and nitric acids introduced by urbanization not only impact the karst groundwater quality, but also result in a significant perturbation to the carbon cycling system in the karst area.

  16. Disclosure of funding sources and conflicts of interest in phase III surgical trials: survey of ten general surgery journals.

    Science.gov (United States)

    Bridoux, Valérie; Moutel, Grégoire; Schwarz, Lilian; Michot, Francis; Herve, Christian; Tuech, Jean-Jacques

    2014-10-01

    Discussions regarding disclosure of funding sources and conflicts of interest (COI) in published peer-reviewed journal articles are becoming increasingly more common and intense. The aim of the present study was to examine whether randomized controlled trials (RCTs) published in leading surgery journals report funding sources and COI. All articles reporting randomized controlled phase III trials published January 2005 through December 2010 were chosen for review from ten international journals. We evaluated the number of disclosed funding sources and COI, and the factors associated with such disclosures. From a review of 657 RCT from the ten journals, we discovered that presence or absence of a funding source and COI was disclosed by 47 % (309) and 25.1 % (165), respectively. Most articles in "International Committee of Medical Journal Editors (ICMJE)-affiliated journals" did not disclose COI. Disclosure of funding was associated with a journal impact factor >3 (51.7 vs 41.6 %; p funding sources (i.e., whether or not there was a funding source), and almost three quarters did not disclose whether COI existed. Our findings suggest the need to adopt best current practices regarding disclosure of competing interests to fulfill responsibilities to readers and, ultimately, to patients.

  17. FATE AND TRANSPORT OF PETROLEUM RELEASED FROM UNDERGROUND STORAGE TANKS in Areas of Karst Topography

    Science.gov (United States)

    The study determines the transport and ultimate fate of petroleum products within a region of karst geomorphology. The paper entails a complete literature review, including references that pertain to contaminant transport within karst aquifers

  18. European survey of diagnosis and management of the polycystic ovary syndrome: results of the ESE PCOS Special Interest Group's Questionnaire.

    Science.gov (United States)

    Conway, Gerard; Dewailly, Didier; Diamanti-Kandarakis, Evanthia; Escobar-Morreale, Hector F; Franks, Steven; Gambineri, Alessandra; Kelestimur, Fahrettin; Macut, Djuro; Micic, Dragan; Pasquali, Renato; Pfeifer, Marija; Pignatelli, Duarte; Pugeat, Michel; Yildiz, Bulent

    2014-10-01

    There is evidence for differences between endocrinologists and other specialists in their approach to diagnosis and management of the polycystic ovary syndrome (PCOS). A mailed survey consisting of a simple questionnaire aiming to understand current practice for diagnosis and management of the PCOS by specialists across Europe. The questionnaire consisted of 23 questions grouped to achieve information on i) the general characteristics of the respondents, ii) patients with PCOS seen by endocrinologists, iii) the main diagnostic criteria, iv) biochemical parameters used in the differential diagnosis of hyperandrogenism, v) long-term concerns, and, finally vi) treatment choices. A total of 357 questionnaires representing 13.3% of the members of European Society of Endocrinology (ESE) were available for final analysis; 93% of the respondents were endocrinologists In relation to the diagnostic criteria, respondents were most likely to select menstrual irregularity as the most frequent criteria used for the diagnosis of PCOS although very high rates were achieved for the use of hirsutism and biochemical hyperandrogenism. It therefore appears that the NIH criteria were followed by the majority of respondents. The most frequent biochemical parameters in the differential diagnosis of hyperandrogenism were total testosterone or free androgen index. Obesity and type 2 diabetes were regarded as the principal long-term concerns for PCOS. The most common treatments for patients with PCOS were metformin (33%), lifestyle modification (25%), and oral contraceptives (22%). More direct treatments of infertility include clomiphene citrate alone or in combination with metformin, prescribed by 9 and 23%, respectively, whereas only 6% used other methods for induction of ovulation. The survey produced by ESE is a good start for evaluating the perspective in the diagnosis and treatment of PCOS by endocrinologists in Europe. © 2014 European Society of Endocrinology.

  19. A survey of smoking prevalence and interest in quitting among social and community service organisation clients in Australia: a unique opportunity for reaching the disadvantaged

    Directory of Open Access Journals (Sweden)

    Paul Christine

    2011-10-01

    Full Text Available Abstract Background Social and community service organisations (SCSOs are non-government, not-for-profit organisations that provide welfare services to disadvantaged individuals. SCSOs hold considerable potential for providing smoking cessation support to disadvantaged smokers. This study aimed to establish the prevalence of smoking, interest in quitting and interest in receiving cessation support amongst clients accessing SCSOs. Methods Clients seeking financial or material assistance from three SCSOs in NSW, Australia, between February and October 2010 were invited to complete a 60-item general health touch screen computer survey. This included questions about smoking status, past quit attempts and interest in receiving support to quit smoking from SCSO staff. Results A total of 552 clients were approached to participate during the study period, of which 383 provided consent and completed the survey (69% consent rate. Daily smoking was reported by 53.5% of participants. Occasional smoking (non-daily smoking was reported by a further 7.9% of participants. Most participants had tried to quit smoking in the past (77% and had made an average of two quit attempts (SD = 3.2 lasting longer than 24 hours in the previous 12 months. More than half of all participants (52.8% reported that they would like help from SCSO staff to quit smoking. For those interested in receiving help, the preferred types of help were access to free NRT (77%, cash rewards (52% and non-cash rewards (47% for quitting, and to receive support and encouragement from SCSO staff to quit (45%. Conclusions Smoking rates among clients accessing SCSO are substantially higher than the general population rate of 15.1%. A substantial proportion of clients are interested in quitting and want support from the SCSO to do so.

  20. Folk use of medicinal plants in Karst and Gorjanci, Slovenia.

    Science.gov (United States)

    Lumpert, Mateja; Kreft, Samo

    2017-02-23

    Information on the use of medicinal plants in Karst and Gorjanci is not available in the literature, but collection of plants is still an important and widespread practice in these regions. Karst and Gorjanci are two remote regions in Slovenia that are only 120 km apart but have different climates; one region is close to the Italian border, and the other is near the Croatian border. Our aim was to report and compare the use of medicinal plants in both regions. From October 2013 to September 2014, 25 informants each in Karst and Gorjanci were interviewed during field research. The age of the informants ranged from 33 to 89 years, with an average age of 61 years in Karst and 69 years in Gorjanci. The main question was "Which plants do or did you collect from nature and use?" Plants of medicinal, nutritive, veterinary or cosmetic use were considered. A total of 78 and 82 taxa were reported in Karst and Gorjanci, respectively; 65 taxa were reported in both regions. Approximately 64% of the plants in each region were distinctive for only a few informants (fewer than 7). The remaining plants were considered important, and the majority were mutual to both regions. Few reported plants were typical for just one region. Differences in the use of some common medicinal plants were observed, e.g., Matricaria chamomilla was used mostly for the treatment of gastrointestinal disorders, respiratory infections and sore eyes in Gorjanci but as a calmative in Karst. Altogether, 15 different oral and 15 different topical medicinal preparations were reported. Folk knowledge was found to be influenced by the media, particularly popular books about medicinal plants that were published in the 20th century. The present research documents the folk use of medicinal plants in Karst and Gorjanci, Slovenia. This rapidly changing practice needs to be documented before it disappears or changes.

  1. Locating karst depressed columns by means of Rn measurement on the surface

    International Nuclear Information System (INIS)

    Tang Daimao; Liu Hongfu; Duan Hongjie; Duan Lindi; Sui Haichen

    1999-01-01

    The coal mining and the related surface projects are extremely harassed by the underground karst depressed columns. The author discussed the surface Rn concentration's abnormality caused by the karst depressed columns. It is concluded that different kinds of karst depressed column can cause different Rn concentration's abnormality. The α-cup Rn measuring instrument was used for detecting Rn abnormality on the surface in order to locate the underground karst depressed columns

  2. Fracture characterization and discrimination criteria for karst and tectonic fractures in the Ellenburger Group, West Texas: Implications for reservoir and exploration models

    Energy Technology Data Exchange (ETDEWEB)

    Hoak, T.E. [Science Applications International Corp., Germantown, MD (United States)]|[Kestrel Geoscience, Littleton, CO (United States); Sundberg, K.R. [Phillips Petroleum Co., Bartlesville, OK (United States); Deyhim, P. [Oklahoma State Univ., Stillwater, OK (United States); Ortoleva, P. [Indiana Univ., Bloomington, IN (United States). Lab. for Computational Geodynamics

    1998-12-31

    In the Ellenburger Group fractured dolomite reservoirs of West Texas, it is extremely difficult to distinguish between multiple phases of karst-related fracturing, modifications to the karst system during burial, and overprinting tectonic fractures. From the analyses of drill core, the authors developed criteria to distinguish between karst and tectonic fractures. In addition, they have applied these criteria within the context of a detailed diagenetic cement history that allows them to further refine the fracture genesis and chronology. In these analyses, the authors evaluated the relationships between fracture intensity, morphologic attributes, host lithology, fracture cement, and oil-staining. From this analysis, they have been able to characterize variations in Ellenburger tectonic fracture intensity by separating these fractures from karst-related features. In general, the majority of fracturing in the Ellenburger is caused by karst-related fracturing although a considerable percentage is caused by tectonism. These findings underscore the importance of considering the complete geologic evolution of a karst reservoir during exploration and field development programs. The authors have been able to more precisely define the spatial significance of the fracture data sets by use of oriented core from Andector Field. They have also demonstrated the importance of these results for exploration and reservoir development programs in West Texas, and the potential to extrapolate these results around the globe. Given the historic interest in the large hydrocarbon reserves in West Texas carbonate reservoirs, results of this study will have tremendous implications for exploration and production strategies targeting vuggy, fractured carbonate systems not only in West Texas, but throughout the globe.

  3. Hydrochemistry and coal mining activity induced karst water quality degradation in the Niangziguan karst water system, China.

    Science.gov (United States)

    Zhang, Xiaobo; Li, Xue; Gao, Xubo

    2016-04-01

    Hydrogeochemical analysis, statistical analysis, and geochemical modeling were employed to evaluate the impacts of coal mining activities on karst water chemistry in Niangziguan spring catchment, one of the largest karst springs in Northern China. Significant water quality deterioration was observed along the flow path, evidenced from the increasing sulfate, nitrate, and TDS content in karst water. Karst water samples are Ca-Mg-HCO3 type in the recharge areas, Ca-Mg-HCO3-SO4 type in the coal mining areas, and Ca-Mg-SO4-HCO3/HCO3-SO4 type in the rural areas and discharge areas. A four-factor principal component analysis (PCA) model is conducted which explains over 82.9% of the total variation. Factor 1, which explained the largest portion (45.33%) of the total variance, reveals that coal mining activities and natural water-rock interaction as the primary factors controlling karst water quality. Anthropogenic effects were recognized as the secondary factor with high positive loadings for NO3 (-) and Cl(-) in the model. The other two factors are co-precipitation removal of trace elements and silicate mineral dissolution, which explained 20.96% of the total variance. A two-end mixing modeling was proposed to estimate the percentage of coal wastewater giving on karst water chemistry, based on the groundwater sulfate chemistry constrains rather than sulfur isotopes. Uncertainty of sulfur isotope sources led to an overestimation of coal mining water contribution. According to the results of the modeling, the contribution of coal mining waste on karst water chemistry was quantified to be from 27.05 to 1.11% which is ca. three times lower than the values suggested using a sulfur isotope method.

  4. Extending GIS Technology to Study Karst Features of Southeastern Minnesota

    Science.gov (United States)

    Gao, Y.; Tipping, R. G.; Alexander, E. C.; Alexander, S. C.

    2001-12-01

    This paper summarizes ongoing research on karst feature distribution of southeastern Minnesota. The main goals of this interdisciplinary research are: 1) to look for large-scale patterns in the rate and distribution of sinkhole development; 2) to conduct statistical tests of hypotheses about the formation of sinkholes; 3) to create management tools for land-use managers and planners; and 4) to deliver geomorphic and hydrogeologic criteria for making scientifically valid land-use policies and ethical decisions in karst areas of southeastern Minnesota. Existing county and sub-county karst feature datasets of southeastern Minnesota have been assembled into a large GIS-based database capable of analyzing the entire data set. The central database management system (DBMS) is a relational GIS-based system interacting with three modules: GIS, statistical and hydrogeologic modules. ArcInfo and ArcView were used to generate a series of 2D and 3D maps depicting karst feature distributions in southeastern Minnesota. IRIS ExplorerTM was used to produce satisfying 3D maps and animations using data exported from GIS-based database. Nearest-neighbor analysis has been used to test sinkhole distributions in different topographic and geologic settings. All current nearest-neighbor analyses testify that sinkholes in southeastern Minnesota are not evenly distributed in this area (i.e., they tend to be clustered). More detailed statistical methods such as cluster analysis, histograms, probability estimation, correlation and regression have been used to study the spatial distributions of some mapped karst features of southeastern Minnesota. A sinkhole probability map for Goodhue County has been constructed based on sinkhole distribution, bedrock geology, depth to bedrock, GIS buffer analysis and nearest-neighbor analysis. A series of karst features for Winona County including sinkholes, springs, seeps, stream sinks and outcrop has been mapped and entered into the Karst Feature Database

  5. Isotopic hydrological studies carried out on the Karst water system

    International Nuclear Information System (INIS)

    Longinelli, A.

    1988-03-01

    The isotopic composition and temperature of many karst springs in the area of Trieste (Italy) have been measured for about three and a half years. During the same period the isotopic composition of precipitation has also been systematically studied. The isotopic composition of springs generally shows variations which are markedly shifted in time with respect to those of precipitation. In most of the springs the heavy isotope contents of winter samples are the highest of the whole year. On the contrary, summer samples normally show quite negative δ-values, the most negative of which often refer to the last summer months. The data obtained are explained in terms of variable mixing of waters from two main reservoirs. The less negative reservoir (in terms of δ) is recharged by ''local'' meteoric waters falling on the westernmost section of the karst area whose mean elevation is about 400 m a.s.l. The most negative reservoir is probably recharged by meteoric waters falling on the Slovenian section of the karst, whose mean elevation is about 800-900 m a.s.l. At least in the case of some of the northernmost karst springs, it is likely that a third water system, basically fed by the Isonzo river, flowing north of the karst area, could interfere with the previously mentioned reservoirs, partially controlling the outflow of some springs. 6 figs

  6. Hydraulic characterisation of karst systems with man-made tracers

    International Nuclear Information System (INIS)

    Werner, A.

    1998-01-01

    Tracer experiments using man-made tracers are common in hydrogeological exploration of groundwater aquifers in karst systems. In the present investigation, a convection-dispersion model (multidispersion model with consideration of several flow paths) and a single-cleft model (consideration of the diffusion between the cleft and the surrounding rock matrix) were used for evaluating tracer experiments in the main hydrological system of the saturated zone of karst systems. In addition to these extended analytical solutions, a numerical transport model was developed for investigating the influence of the transient flow rate on the flow and transport parameters. Comparative evaluations of the model approaches for the evaluation of tracer experiments were made in four different karst systems: Danube-Aach, Paderborn, Slowenia and Lurbach, of which the Danube-Aach system was considered as the most important. The investigation also comprised three supplementary experiments in order to enable a complete hydraulic characterisation of the system. (orig./SR) [de

  7. Prevalence and interest in the practice of scratch testing for contact urticaria: a survey of the American contact dermatitis society members.

    Science.gov (United States)

    Orb, Quinn; Millsop, Jillian Wong; Harris, KaLynne; Powell, Douglas

    2014-01-01

    Contact urticaria (CU) is the development of a wheal and flare on the skin after topical exposure to a particular chemical or compound. It can be diagnosed through a variety of techniques. Many chemicals that cause a type IV allergy can also cause CU. The incidence of CU to these chemicals is unknown. The aim of this study was to evaluate the opinions of the American Contact Dermatitis Society members regarding CU and scratch testing. We distributed an electronic survey to the American Contact Dermatitis Society members regarding observed prevalence of CU, frequency of scratch testing in clinical practice, and interest in learning about scratch testing in diagnosing CU and other skin contact conditions. We distributed 508 surveys and received 133 responses. Seventeen percent reported that CU was extremely rare, 32% reported that CU was rare, and 38.9% reported that CU was infrequent. Alternatively, 10.7% believed that CU was common, and 1.5% believed that CU was extremely common. A minority, 19.1%, performed scratch testing on patients with suspected CU. Most respondents, 54.6%, were interested in learning about scratch testing. Additional education regarding scratch testing could increase comfort and use of scratch testing in clinical practice. Further studies are needed to evaluate the prevalence of CU in the general population and better guide the use of testing for dermatologic patients.

  8. Eogenetic karst, glacioeustatic cave pools and anchialine environments on Mallorca Island: a discussion of coastal speleogenesis.

    Directory of Open Access Journals (Sweden)

    Angel Ginès

    2007-07-01

    10 km, as shown by scuba-diving surveys. Careful observations and detailed mapping of caves in the Upper Miocene reef rocks of Mallorca permit a better understanding of the coastal speleogenetic processes involved in a typical eogenetic karst over time ranges greater than 1 Ma. The role played by recurrent glacioeustatic oscillations of sea level and the subsequent rises and falls of the water table are emphasized in our model. There are two associated mechanisms: the triggering of breakdown by the loss of buoyant support that follows each lowering of sea level (i.e., during glaciations or smaller cold events and the later underwater solution of boulders and collapse debris (during high sea levels that correspond to interglacial events. Additionally, tidal fluctuations affecting groundwaters would enhance solutional enlargement of caves and vug-porosity connected to the sea, rather than conventional karstic flow through conduits that probably is not as important an agent in eogenetic speleogenesis.

  9. Integration of potential and quasipotential geophysical fields and GPR data for delineation of buried karst terranes in complex environments

    Science.gov (United States)

    Eppelbaum, L. V.; Alperovich, L. S.; Zheludev, V.; Ezersky, M.; Al-Zoubi, A.; Levi, E.

    2012-04-01

    Karst is found on particularly soluble rocks, especially limestone, marble, and dolomite (carbonate rocks), but is also developed on gypsum and rock salt. Subsurface carbonate rocks involved in karst groundwater circulation considerably extend the active karst realm, to perhaps 14% of the world's land area (Price, 2009). The phenomenon of the solution weathering of limestone is the most widely known in the world. Active sinkholes growth appears under different industrial constructions, roads, railways, bridges, airports, buildings, etc. Regions with arid and semi-arid climate occupy about 30% of the Earth's land. Subsurface in arid regions is characterized by high variability of physical properties both on lateral and vertical that complicates geophysical survey analysis. Therefore for localization and monitoring of karst terranes effective and reliable geophysical methodologies should be applied. Such advanced methods were developed in microgravity (Eppelbaum et al., 2008; Eppelbaum, 2011b), magnetic (Khesin et al., 1996; Eppelbaum et al., 2000, 2004; Eppelbaum, 2011a), induced polarization (Khesin et al., 1997; Eppelbaum and Khesin, 2002), VLF (Eppelbaum and Khesin, 1992; Eppelbaum and Mishne, 2012), near-surface temperature (Eppelbaum, 2009), self-potential (Khesin et al., 1996; Eppelbaum and Khesin, 2002), and resistivity (Eppelbaum, 1999, 2007a) surveys. Application of some of these methodologies in the western and eastern shores of the Dead Sea area (e.g., Eppelbaum et al., 2008; Ezersky et al., 2010; Al-Zoubi et al., 2011) and in other regions of the world (Eppelbaum, 2007a) has shown their effectiveness. The common procedures for ring structure identification against the noise background and probabilistic-deterministic methods for recognizing the desired targets in complex media are presented in Khesin and Eppelbaum (1997), Eppelbaum et al. (2003), and Eppelbaum (2007b). For integrated analysis of different geophysical fields (including GPR images) intended

  10. Karst geomorphology and hydrology at the Campania - Basilicata border (southern Apennines of Italy)

    Science.gov (United States)

    Farfan Gonzalez, H.; Parise, M.

    2009-04-01

    This paper describes the main karst geomorphological and hydrological features of the area at the boundary between the Campania and Basilicata regions, in the southern Apennines of Italy. Even not far from the most important karst area of southern Italy (the Alburni Massif, hosting hundreds of caves, with very complex subterranean systems that have been extensively explored in the last 50 years), this sector has never been object of detailed karstic studies. Geologically, it shows a carbonate bedrock consisting of Cretaceous limestones and dolomites, in tectonic contact with terrigenous deposits of Miocene age. The territory is an active seismogenic zone, as testified by the November 23, 1980, earthquake that hit this part of southern Italy with a 6.8 magnitude, causing over 2,700 victims and destroying several small towns in the two regions. In 2007, within the framework of joint projects between the Italian Speleological Society (SSI) and the Cuban Speleological Society (SEC), a scientific and speleological expedition was carried out in a sector of this area. The efforts produced during the expedition, and in the preceeding phases as well, resulted in discovery, survey and documentation of 62 caves, and in supporting the progresses of the exploration activities in the main karst system in the area, a complex of two caves that reach a maximum depth of 123 meters and an overall length of 1,8 km. At the surface, a variety of karst landforms is recognizable. The main carbonate ridges show several orders of palaeosurfaces, located at different heights above sea level. Bounded by fault lines or fault line scarps, they present variable extension, the highest surfaces showing a much better continuity. On the Campanian side, several sinkholes are also present, some of which opened in the aftermath of the 1980 earthquake. The same event caused in Basilicata the formation of several caves of structural origin, controlled in their development by tectonics and extremely

  11. Subterranean karst environments as a global sink for atmospheric methane

    Science.gov (United States)

    Webster, Kevin D.; Drobniak, Agnieszka; Etiope, Giuseppe; Mastalerz, Maria; Sauer, Peter E.; Schimmelmann, Arndt

    2018-03-01

    The air in subterranean karst cavities is often depleted in methane (CH4) relative to the atmosphere. Karst is considered a potential sink for the atmospheric greenhouse gas CH4 because its subsurface drainage networks and solution-enlarged fractures facilitate atmospheric exchange. Karst landscapes cover about 14% of earth's continental surface, but observations of CH4 concentrations in cave air are limited to localized studies in Gibraltar, Spain, Indiana (USA), Vietnam, Australia, and by incomplete isotopic data. To test if karst is acting as a global CH4 sink, we measured the CH4 concentrations, δ13CCH4, and δ2HCH4 values of cave air from 33 caves in the USA and three caves in New Zealand. We also measured CO2 concentrations, δ13CCO2, and radon (Rn) concentrations to support CH4 data interpretation by assessing cave air residence times and mixing processes. Among these caves, 35 exhibited subatmospheric CH4 concentrations in at least one location compared to their local atmospheric backgrounds. CH4 concentrations, δ13CCH4, and δ2HCH4 values suggest that microbial methanotrophy within caves is the primary CH4 consumption mechanism. Only 5 locations from 3 caves showed elevated CH4 concentrations compared to the atmospheric background and could be ascribed to local CH4 sources from sewage and outgassing swamp water. Several associated δ13CCH4 and δ2HCH4 values point to carbonate reduction and acetate fermentation as biochemical pathways of limited methanogenesis in karst environments and suggest that these pathways occur in the environment over large spatial scales. Our data show that karst environments function as a global CH4 sink.

  12. Analysis of TCE Fate and Transport in Karst Groundwater Systems Using Statistical Mixed Models

    Science.gov (United States)

    Anaya, A. A.; Padilla, I. Y.

    2012-12-01

    Karst groundwater systems are highly productive and provide an important fresh water resource for human development and ecological integrity. Their high productivity is often associated with conduit flow and high matrix permeability. The same characteristics that make these aquifers productive also make them highly vulnerable to contamination and a likely for contaminant exposure. Of particular interest are trichloroethylene, (TCE) and Di-(2-Ethylhexyl) phthalate (DEHP). These chemicals have been identified as potential precursors of pre-term birth, a leading cause of neonatal complications with a significant health and societal cost. Both of these contaminants have been found in the karst groundwater formations in this area of the island. The general objectives of this work are to: (1) develop fundamental knowledge and determine the processes controlling the release, mobility, persistence, and possible pathways of contaminants in karst groundwater systems, and (2) characterize transport processes in conduit and diffusion-dominated flow under base flow and storm flow conditions. The work presented herein focuses on the use of geo-hydro statistical tools to characterize flow and transport processes under different flow regimes, and their application in the analysis of fate and transport of TCE. Multidimensional, laboratory-scale Geo-Hydrobed models (GHM) were used for this purpose. The models consist of stainless-steel tanks containing karstified limestone blocks collected from the karst aquifer formation of northern Puerto Rico. The models integrates a network of sampling wells to monitor flow, pressure, and solute concentrations temporally and spatially. Experimental work entails injecting dissolved CaCl2 tracers and TCE in the upstream boundary of the GHM while monitoring TCE and tracer concentrations spatially and temporally in the limestone under different groundwater flow regimes. Analysis of the temporal and spatial concentration distributions of solutes

  13. Review: Characterization, evolution, and environmental issues of karst water systems in Northern China

    Science.gov (United States)

    Liang, Yongping; Gao, Xubo; Zhao, Chunhong; Tang, Chunlei; Shen, Haoyong; Wang, Zhiheng; Wang, Yanxin

    2018-05-01

    In Northern China, karst systems in widely distributed carbonate rocks are one of the most important water supplies for local inhabitants. Constrained by the specific geological and geomorphological conditions, most karst water in this region is discharged as individual or groups of springs. This paper summarizes the characteristics, chemistry, and environmental quality of these karst systems in Northern China. Five structural models of karst water systems were identified based on the relationships between the karst geological strata and karst groundwater flow fields. These specific structural models may closely relate to the attendant environmental geological issues and consistent risks from pollution. Over the past 40 years, the karst water systems in Northern China have suffered from various environmental problems, including deteriorating water quality, the drying up of springs, a continuous decline in the level of karst water, and so on. Based on the field investigation and previous data, a preliminary summary is provided of the environmental problems related to the development and evolutionary trends of karst water in this region. The results highlight the significant challenges associated with karst water, and it is essential that all segments of society be made aware of the situation in order to demand change. In addition, the study provides a scientific basis for the management, protection, and sustainable utilization of karst water resources.

  14. Macroinvertebrate diversity in the karst Jadro River (Croatia

    Directory of Open Access Journals (Sweden)

    Rađa Biljana

    2008-01-01

    Full Text Available This paper presents the results of 10 years of investigation of the aquatic macroinvertebrate fauna along the karst Jadro River. The Jadro is a typical karst river. Benthic macroinvertebrates were collected along the river at 15 sites by standard methods of sampling, in addition to which several physicochemical parameters were also determined. Based on qualitative and quantitative composition of the macroinvertebrate fauna, correspondence analysis divided the river course into three sections: upstream, midcourse, and downstream. Forty-three taxa were recorded. Results of saprobiological analysis based on macrozoobenthos indicate that water of the Jadro River belongs to quality classes I and II.

  15. Management of an Underground River to Overcome Water Scarcity in the Gunung Sewu Karst Area, Indonesia

    Directory of Open Access Journals (Sweden)

    Choirul Amin

    2017-07-01

    Full Text Available Since people living in a karst area periodically face a crisis due to a lack of fresh water, it is necessary to re-evaluate the ability to use water resources. An appropriate and effective management is required to use available water resource sustainably. We describe a management process of exploring underground river in karst region as water resources. The activities completed included four phases, namely exploration, pre-lifting activities, the water lifting and post-lifting activities. The exploration phase included speleological surveys and data collection for the cave mouth using remote sensing instrument. The pre-lifting was done to prepare various requirements before the lifting process was completed. The water lifting phase consisted of the construction of an underground river dam, the installation of submersible pumps, the construction of reservoirs and the installation of piping to connect to the public hydrant. The post-lifting phase was mainly conducted to organise water distribution evenly. This management model was evidenced to successfully overcome drought in Pucung village by providing fresh water to the local community. Moreover, this model promoted residents’ cost savings by reducing their expenses for buying water from IDR 50,000/m3 to IDR 3,500/m3 (1,300 percent.

  16. Discovery of ancient Roman "highway" reveals geomorphic changes in karst environments during historic times.

    Science.gov (United States)

    Bernardini, Federico; Vinci, Giacomo; Forte, Emanuele; Furlani, Stefano; Pipan, Michele; Biolchi, Sara; De Min, Angelo; Fragiacomo, Andrea; Micheli, Roberto; Ventura, Paola; Tuniz, Claudio

    2018-01-01

    Sinkholes are a well-known geologic hazard but their past occurrence, useful for subsidence risk prediction, is difficult to define, especially for ancient historic times. Consequently, our knowledge about Holocene carbonate landscapes is often limited. A multidisciplinary study of Trieste Karst (Italy), close to early Roman military fortifications, led to the identification of possible ancient road tracks, cut by at least one sinkhole. Electrical Resistivity Tomography through the sinkhole has suggested the presence of a cave below its bottom, possibly responsible of the sinkhole formation, while Ground Penetrating Radar has detected no tectonic disturbances underneath the tracks. Additionally, archaeological surveys led to the discovery of over 200 Roman shoe hobnails within or close to the investigated route. According to these data, the tracks are interpreted as the remains of a main Roman road, whose itinerary has been reconstructed for more than 4 km together with other elements of ancient landscape. Our results provide the first known evidence of a Roman main road swallowed by sinkholes and suggest that Holocene karst landscapes could be much different from what previously believed. In fact, sinkholes visible nowadays in the investigated region could have been flat areas filled by sediments up to the Roman time.

  17. Heat exchange modeling in a multilayered karst aquifer affected by seawater intrusion

    Directory of Open Access Journals (Sweden)

    Luca Vettorello

    2015-11-01

    Full Text Available A Feflow thermohaline model has been implemented in order to study borehole heat exchangers (BHEs activity in a coastal aquifer in the South of Italy (Province of Lecce, Puglia Region. The modeled closed-loop system consists of two double u-pipe heat exchangers, installed in 200 meters deep boreholes. The main purpose of numerical modeling was to forecast thermal plume extension in groundwater after a long period of heat exchange, calculating temperature trends in observation points during a 10 years transport simulation. The complex geological structure, including calcarenites, fractured limestones and a deep karst aquifer, has been translated into a multilayered model, with a depth-related parameter distribution, assigning different values of hydraulic, thermal and chemical properties to each layer. In particular saltwater concentration has been taken into account, considering the influence of seawater intrusion on the heat transport density-dependent model. Parameters assignment was based on experimental datasets collected during initial field investigations, including thermal characterization of soil samples and GRTs, together with historical hydrogeological and hydrochemical measures and previous groundwater surveys. After model structure configuration and aquifers parameterization, a sensitivity analysis on porosity and heat dispersivity has been conducted, to evaluate their influence on thermal transport phenomena with a multiple scenarios approach, considering in particular the uncertainty related to secondary porosity in karst systems. Feflow simulation represented the first step in environmental compatibility evaluation for the BHE plant, waiting for the necessary model calibration with groundwater temperature monitoring trends.

  18. Humus soil as a critical driver of flora conversion on karst rock outcrops.

    Science.gov (United States)

    Zhu, Xiai; Shen, Youxin; He, Beibei; Zhao, Zhimeng

    2017-10-03

    Rock outcrop is an important habitat supporting plant communities in karst landscape. However, information on the restoration of higher biotic populations on outcrops is limited. Here, we investigated the diversity, biomass changes of higher vascular plants (VP) and humus soil (HS) on karst outcrops during a restoration process. We surveyed VP on rock outcrops and measured HS reserved by various rock microhabitats in a rock desertification ecosystem (RDE), an anthropogenic forest ecosystem (AFE), and a secondary forest ecosystem (SFE) in Shilin County, southwest China. HS metrics (e.g. quantity and nutrients content) and VP metrics (e.g. richness, diversity and biomass) were higher at AFE than at RDE, but lower than at SFE, suggesting that the restoration of soil subsystem vegetation increased HS properties and favored the succession of VP on rock outcrops. There was significantly positive correlation between VP metrics and HS amount, indicating that the succession of VP was strongly affected by availability and heterogeneity of HS in various rock microhabitats. Thus, floral succession of rock subsystem was slow owing to the limited resources on outcrops, although the vegetation was restored in soil subsystem.

  19. Relative importance of natural and anthropogenic factors influencing karst rocky desertification

    Science.gov (United States)

    Xu, Erqi; Zhang, Hongqi

    2017-04-01

    As the most severe ecological issue in southwest China, karst rocky desertification (KRD) has both threatened and constrained regional sustainable development. Comprehensively understanding the relationship between the evolution of KRD and relevant driving data would provide more information to combat KRD in such complex karst environments. Past studies have been limited in quantifying the relative importance of driving factors influencing fine-scale KRD evolution, and have also lacked insight into their interactive impacts. To address these issues, we have used geographical information system techniques and a geographical detector model to explore the spatial consistency of driving factors and their interactions in relation to the evolution of KRD. Changshun County in China was selected as a representative area for the study. Nine relevant driving factors, including both natural and anthropogenic factors, were studied in regard to their relationships with KRD transformation between 2000 and 2010. Our results demonstrate the relative importance of driving data in influencing the improvement and deterioration of KRD. Lithology, soil type and road influence are identified as the leading factors. Interestingly, to our study at least, there is no significant difference between the impacts of natural and anthropogenic factors influencing KRD improvement, and even natural factors have a higher impact on KRD deterioration. Factors were found to enhance the influence of each other for KRD transformation. In particular, the results show a non-linearly enhanced effect between driving factors, which significantly aggravates KRD. New information found in our study helps to effectively control and restore areas afflicted by KRD.

  20. Prevalence and characteristics of smokers interested in internet-based smoking cessation interventions: cross-sectional findings from a national household survey.

    Science.gov (United States)

    Brown, Jamie; Michie, Susan; Raupach, Tobias; West, Robert

    2013-03-18

    An accurate and up-to-date estimate of the potential reach of Internet-based smoking cessation interventions (ISCIs) would improve calculations of impact while an understanding of the characteristics of potential users would facilitate the design of interventions. This study reports the prevalence and the sociodemographic, smoking, and Internet-use characteristics of smokers interested in using ISCIs in a nationally representative sample. Data were collected using cross-sectional household surveys of representative samples of adults in England. Interest in trying an Internet site or "app" that was proven to help with stopping smoking was assessed in 1128 adult smokers in addition to sociodemographic characteristics, dependence, motivation to quit, previous attempts to quit smoking, Internet and handheld computer access, and recent types of information searched online. Of a representative sample of current smokers, 46.6% (95% CI 43.5%-49.6%) were interested in using an Internet-based smoking cessation intervention. In contrast, only 0.3% (95% CI 0%-0.7%) of smokers reported having used such an intervention to support their most recent quit attempt within the past year. After adjusting for all other background characteristics, interested smokers were younger (OR=0.98, 95% CI 0.97-0.99), reported stronger urges (OR=1.29, 95% CI 1.10-1.51), were more motivated to quit within 3 months (OR=2.16, 95% CI 1.54-3.02), and were more likely to have made a quit attempt in the past year (OR=1.76, 95% CI 1.30-2.37), access the Internet at least weekly (OR=2.17, 95% CI 1.40-3.36), have handheld computer access (OR=1.65, 95% CI 1.22-2.24), and have used the Internet to search for online smoking cessation information or support in past 3 months (OR=2.82, 95% CI 1.20-6.62). There was no association with social grade. Almost half of all smokers in England are interested in using online smoking cessation interventions, yet fewer than 1% have used them to support a quit attempt in the

  1. Land use and human impact in the Dinaric karst.

    Directory of Open Access Journals (Sweden)

    Gams Ivan

    1999-01-01

    Full Text Available The artice presents Dinaric karst, human impacts in the area, and its long history of deforestation, transformation into stony semi-desert, and a century long reforestation, where plans to restore the primary thick soil were just hoping against hope.

  2. Simulation of Cavern Formation and Karst Development Using Salt

    Science.gov (United States)

    Kent, Douglas C.; Ross, Alex R.

    1975-01-01

    A salt model was developed as a teaching tool to demonstrate the development of caverns and karst topography. Salt slabs are placed in a watertight box to represent fractured limestone. Erosion resulting from water flow can be photographed in time-lapse sequence or demonstrated in the laboratory. (Author/CP)

  3. Review: The Yucatán Peninsula karst aquifer, Mexico

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Gondwe, Bibi Ruth Neuman; Charvet, Guillaume

    2011-01-01

    in the vicinity of the North American/Caribbean plate boundary and has been reshaped by a series of tectonic events over its long geologic history. At the end of the Cretaceous period, the Yucatán Peninsula was hit by a large asteroid, which formed the Chicxulub impact crater. The Yucatán Peninsula karst aquifer...

  4. Determining hydraulic parameters of a karst aquifer using unique ...

    African Journals Online (AJOL)

    Although karst aquifers constitute some of the most important water resources worldwide, generally accepted methods for reliably characterising their hydraulic properties are still elusive. This paper aims at contributing to the discussion by a first-ever attempt to utilise various sets of unique historical data derived from ...

  5. Mechanism of water inrush in tunnel construction in karst area

    Directory of Open Access Journals (Sweden)

    Liping Li

    2016-05-01

    Full Text Available With the rapid developing trend of long, large and deep construction characteristics for underground engineering in the world, China has the largest number of karst tunnels with the wide scales and great difficulties. As the hydrogeological conditions are becoming unprecedentedly complex, water inrush disaster becomes the bottleneck problem for the further development of traffic tunnels. Based on the statistical analysis of a large number of cases of water inrush in karst tunnels, influence factors of water inrush have been put forward from the view of karst hydrogeological factors and engineering disturbance of human factors. Karst hydrogeological factors include geological defect, strata dip, formation lithology, landform and underground level. Human factors of engineering disturbance include excavation and reinforcement geological prediction, monitoring and measurement of surrounding rock. It also introduces some geological disasters caused by the water inrush in tunnel excavation. In terms of the formation of water inrush channel, water inrush types are divided into geological defects inrush, non-geological defects inrush and the combination. Conclusions will be beneficial to further research on hazards control of underground construction.

  6. [Conflict of interest with industry--a survey of nurses in the field of wound care in Germany, Australia and Switzerland].

    Science.gov (United States)

    Panfil, Eva-Maria; Zima, Karoline; Lins, Sabine; Köpke, Sascha; Langer, Gero; Meyer, Gabriele

    2014-06-01

    Nurses in the field of wound care are increasingly being courted by the wound industry. A survey regarding nurses' perceptions and participation in pharmaceutical marketing was conducted. Based on existing instruments, a standardized questionnaire (39 items, 5-point Likert scale) was developed. It was sent electronically and by mail to all nursing members of the Austrian Society for Vascular Care (ÖGvP), the German Wound Healing Society (DGfW e. V.) and the Swiss Association for Wound Care (SAfW). 178 nurses participated in the survey (75 % women; aged 27 - 70 years [median 45], 0 - 40 years [median 9] practice in the area of the wound care). Only about one fourth of the respondents (23,0 %) did not participate in pharmaceutical marketing last year. Generally small gifts were more frequently received than expensive gifts. Most of the nurses valued inexpensive gifts, educational gifts and gifts with patient benefit as appropriate. The majority of respondents consider themselves as less influenceable in decision making, compared to physicians. The behavior and attitude of nurses are ambivalent. The occurrence of conflict of interest is partly justified by perceived patient benefit. Lack of knowledge about the topic and social desirability could be the cause of an uncritical attitude. For a more critical approach education and ethical standards are necessary.

  7. Past and present management of water resources in karst environments

    Science.gov (United States)

    Parise, Mario

    2010-05-01

    Karst is a very peculiar environment, and has a number of intrinsic features that clearly distinguish it from any other natural setting. Hydrology of karst is dominated by absence or very scarce presence of surface runoff, since water rapidly infiltrates underground through the complex network of conduits and fissures that are at the origin of the development of karst caves. The limited presence of water at the surface represented the main problem to be faced by man, starting from the very first historic phases of establishing settlements in karst territories. As often happens in areas with limited natural resources, man was however able to understand the local environment through observations and direct experience, develop technique in order to collect the limited available water resources, and adapt his way of life to the need of the natural environment. In a few words, a sustainable use of the water resources was reached, that went on for many centuries, allowing development of human settlements and agriculture, and, at the same time, protecting and safeguarding the precious hydric resources. Some of the most typical rural architectures built in karst areas of the Mediterranean Basin can be described as examples of such efforts: from the dry stone walls, to many types of storage-houses or dwellings, known with different names, depending upon the different countries and regions. Dry stone walls, in particular, deserve a particular attention, since they had multiple functions: to delimit the fields and properties, to act as a barrier to soil erosion, to allow terracing the high-gradient slopes, to collect and store water. At this latter aim, dry stone walls were build in order to create a small but remarkable micro-environment, functioning as collectors of moisture and water vapour. In the last centuries, with particular regard to the last decades of XX century, the attention paid by man to the need of the natural environment has dramatically changed. This

  8. Imaging of karsts on buried carbonate platform in Central Luconia Province, Malaysia

    Science.gov (United States)

    Nur Fathiyah Jamaludin, Siti; Mubin, Mukhriz; Latiff, Abdul Halim Abdul

    2017-10-01

    Imaging of carbonate rocks in the subsurface through seismic method is always challenging due to its heterogeneity and fast velocity compared to the other rock types. Existence of karsts features on the carbonate rocks make it more complicated to interpret the reflectors. Utilization of modern interpretation software such as PETREL and GeoTeric® to image the karsts morphology make it possible to model the karst network within the buried carbonate platform used in this study. Using combination of different seismic attributes such as Variance, Conformance, Continuity, Amplitude, Frequency and Edge attributes, we are able to image the karsts features that are available in the proven gas-field in Central Luconia Province, Malaysia. The mentioned attributes are excellent in visualize and image the stratigraphic features based on the difference in their acoustic impedance as well as structural features, which include karst. 2D & 3D Karst Models were developed to give a better understanding on the characteristics of the identified karsts. From the models, it is found that the karsts are concentrated in the top part of the carbonate reservoir (epikarst) and the middle layer with some of them becomes extensive and create karst networks, either laterally or vertically. Most of the vertical network karst are related to the existence of faults that displaced all the horizons in the carbonate platform.

  9. Fractal Prediction of Grouting Volume for Treating Karst Caverns along a Shield Tunneling Alignment

    Directory of Open Access Journals (Sweden)

    Wen-Chieh Cheng

    2017-06-01

    Full Text Available Karst geology is common in China, and buried karst formations are widely distributed in Guangdong province. In the process of shield tunneling, the abundant water resources present in karst caverns could lead to the potential for high water ingress, and a subsequent in situ stress change-induced stratum collapse. The development and distribution of karst caverns should therefore be identified and investigated prior to shield tunnel construction. Grouting is an efficient measure to stabilize karst caverns. The total volume of karst caverns along the shield tunneling alignment, and its relationship with the required volume of grouts, should be evaluated in the preliminary design phase. Conventionally, the total volume of karst caverns is empirically estimated based on limited geological drilling hole data; however, accurate results are rarely obtained. This study investigates the hydrogeology and engineering geology of Guangzhou, the capital of Guangdong province, and determines the fractal characteristics of the karst caverns along the tunnel section of Guangzhou metro line no. 9. The karst grouting coefficients (VR were found to vary from 0.11 in the case of inadequate drilling holes to 1.1 in the case where adequate drilling holes are provided. A grouting design guideline was furthermore developed in this study for future projects in karst areas.

  10. A model of karst systems of the Usturt plateau (Middle Asia)

    International Nuclear Information System (INIS)

    Victorov, A. S.

    2016-01-01

    The issues relating to the structure and development of desert karst is currently one of the least studied problems. The goal of the research efforts presented in this paper was to create a model of karst systems in the Usturt Plateau and, primarily, of the systems formed by the prevailing numerous surface karst landforms. The model is based on the following main assumptions: the process of emergence of the karst phenomena is probabilistic and occurs independently at non-intersecting sites; the probability of emergence of one depression at a reference site depends only on its area. The increase of the dimensions of a karst landform is a random process that occurs independently of other karst landforms, its speed is governed by random factors, and it is directly proportionate to the existing dimensions of the landform. The model does not assume constancy of climatic characteristics. The testing was conducted at several reference sites of the Usturt Plateau. The research allowed us to reach the following conclusions: the karst depressions of the Usturt Plateau, which are the typical forms of desert karst, are governed by the Poisson distribution of their centres and by the lognormal distribution of their dimensions, similar to the karst depressions in a humid climate. The results may be used in assessments of karst hazard for linear and areal structures, as well as for small-dimensional structures. (Author)

  11. Characterizing the Business Skills of the Public Health Workforce: Practical Implications From the Public Health Workforce Interests and Needs Survey (PH WINS).

    Science.gov (United States)

    Kornfeld, Julie; Sznol, Joshua; Lee, David

    2015-01-01

    Public health financial competencies are often overlooked or underrepresented in public health training programs. These skills are important for public health workforce members who are involved in managing resources and strategic planning and have been defined as key competencies by several national entities. To characterize business skills among state health agency employees and examine self-reported skill levels and their association with job satisfaction, worksite training and development opportunities, and annual salary. A cross-sectional survey, the Public Health Workforce Interests and Needs Survey (PH WINS), of state health agency central office employees was conducted in 2014. Multivariable logistic regression analyses, controlling for job classification, supervisory status, years of public health practice, annual compensation, educational attainment, geographic region, and sociodemographic status, were used to assess the relationship between business skills and training environment and job satisfaction. Linear regression was used to correlate business skills and annual compensation. A total of 10,246 state health agency staff completed a Web-based survey. Self-reported proficiency in business skills, job satisfaction, opportunities for training, and annual salary. The workforce reported high levels of proficiency in applying quality improvement concepts and managing change (67.5% and 69.2%, respectively). Half of the respondents reported proficiency in budget skills (49.3%). Participants who were proficient in applying quality improvement concepts were significantly more likely to report job satisfaction (OR = 1.27). A supportive training environment was significantly associated with business competencies (range of OR = 1.08-1.11). Managing change (β = .15) and budget skill proficiency (β = .37) were significantly associated with increased yearly compensation. Public health workers who self-report proficiency with business skills report increased job

  12. STUDY ON KARST INFORMATION IDENTIFICATION OF QIANDONGNAN PREFECTURE BASED ON RS AND GIS TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    M. Yao

    2018-04-01

    Full Text Available Karst area is a pure natural resource base, at the same time, due to the special geological environment; there are droughts and floods alternating with frequent karst collapse, rocky desertification and other resource and environment problems, which seriously restrict the sustainable economic and social development in karst areas. Therefore, this paper identifies and studies the karst, and clarifies the distribution of karst. Provide basic data for the rational development of resources in the karst region and the governance of desertification. Due to the uniqueness of the karst landscape, it can’t be directly recognized and extracted by computer in remote sensing images. Therefore, this paper uses the idea of “RS + DEM” to solve the above problems. this article is based on Landsat-5 TM imagery in 2010 and DEM data, proposes the methods to identify karst information research what is use of slope vector diagram, vegetation distribution map, distribution map of karst rocky desertification and other auxiliary data in combination with the signs for human-computer interaction interpretation, identification and extraction of peak forest, peaks cluster and isolated peaks, and further extraction of karst depression. Experiments show that this method achieves the “RS + DEM” mode through the reasonable combination of remote sensing images and DEM data. It not only effectively extracts karst areas covered with vegetation, but also quickly and accurately locks down the karst area and greatly improves the efficiency and precision of visual interpretation. The accurate interpretation rate of karst information in study area in this paper is 86.73 %.

  13. Stable isotope hydrology of a classical karst area, Trieste, Italy

    International Nuclear Information System (INIS)

    Flora, O.; Longinelli, A.

    1989-01-01

    Most of the karst springs that exist along the northeastern coast of the Adriatic Sea in the area of Trieste (Italy) have been studied for about 2 years. These studies were carried out to determine the oxygen isotopic composition of the water and, more recently, the major and minor dissolved ions and the water temperature. The isotopic composition of meteoric waters in different areas was also systematically studied during the same period to obtain basic information on environmental waters. The isotopic curves obtained from the springs generally showed a marked seasonal isotopic inversion. In fact, in most of the springs studied the results obtained from winter samples were the most positive. In contrast, summer samples were usually quite negative, the most negative being those obtained in the late summer months (August to October). The data obtained were considered to be the result of a variable mixing of waters from two different reservoirs. The less negative data probably resulted from 'local' meteoric waters falling on the western section of the karst area, at a mean elevation of about 400 metres above sea level. The most negative data were probably related to meteoric waters falling on the internal part of the karst area, at a mean elevation of about 800 to 900 metres. The isotopic values and the chemistry of the waters appeared to be in reasonable agreement. However, at least in the northern karst springs, it is likely that a third water system, basically fed by the Isonzo River which flows north of the karst highlands, might interfere with the previously mentioned reservoirs, so partially controlling the outflow of some of these springs. (author). 7 refs, 8 figs

  14. Eogenetic karst hydrology: insights from the 2004 hurricanes, peninsular Florida.

    Science.gov (United States)

    Florea, Lee J; Vacher, H L

    2007-01-01

    Eogenetic karst lies geographically and temporally close to the depositional environment of limestone in warm marine water at low latitude, in areas marked by midafternoon thunderstorms during a summer rainy season. Spring hydrographs from such an environment in north-central Florida are characterized by smooth, months-long, seasonal maxima. The passage of Hurricanes Frances and Jeanne in September 2004 over three field locations shows how the eogenetic karst of the Upper Floridan Aquifer responds to unequivocal recharge events. Hydrographs at wells in the High Springs area, Rainbow Springs, and at Morris, Briar, and Bat Caves all responded promptly with a similar drawn-out rise to a maximum that extended long into the winter dry season. The timing indicates that the typical hydrograph of eogenetic karst is not the short-term fluctuations of springs in epigenic, telogenetic karst, or the smoothed response to all the summer thunderstorms, but rather the protracted response of the system to rainfall that exceeds a threshold. The similarity of cave and noncave hydrographs indicates distributed autogenic recharge and a free communication between secondary porosity and permeable matrix-both of which differ from the hydrology of epigenic, telogenetic karst. At Briar Cave, drip rates lagged behind the water table rise, suggesting that recharge was delivered by fractures, which control the cave's morphology. At High Springs, hydrographs at the Santa Fe River and a submerged conduit apparently connected to it show sharp maxima after the storms, unlike the other cave hydrographs. Our interpretation is that the caves, in general, are discontinuous.

  15. [Characteristic of ammonia nitrogen adsorption on karst underground river sediments].

    Science.gov (United States)

    Guo, Fang; Chen, Kun-Kun; Jiang, Guang-Hui

    2011-02-01

    Karst aquifers are one of the most important aquifers in Southwestern China. One of the characteristics of karst aquifers is the enhanced permeability permits high flow velocities are capable of transporting suspended and bedload sediments. Mobile sediment in karst may act as a vector for the transport of contaminates. 14 sediment samples were collected from two underground rivers in two typical karst areas in Liuzhou city, Guangxi Autonomous Region, China. According to simulated experiment methods, characteristic of adsorption of ammonia nitrogen on sediment was studied. The results of ammonia nitrogen adsorption dynamics on sediments showed that the maximum adsorption velocity was less than 2 h. The adsorption balance quantity in 5 h accounted for 71% - 98% of the maximum adsorption quantity. The maximum adsorption quantity of ammonia nitrogen was 385.5 mg/kg, which was sediment from a cave in the middle areas of Guancun underground river system. The study of isotherm adsorption indicated adsorption quantity of NH4+ increase followed by incremental balance concentration of NH4+ in the aquatic phase. Adsorption quantity of ammonia nitrogen in sediments has a relative linear relationship with adsorption balance concentrations. Adsorption-desorption balance concentrations were all low, indicating sediments from underground rivers have great adsorption potential. Under the condition of low and high concentrations of ammonia nitrogen in overlying water, Langmuir and Tempkin couldn't simulate or simulate results couldn't reach remarkable level, whilst Linear and Freundlich models could simulate well. Research on different type sediments, sampling times and depths from two underground rivers shows characteristic of ammonia nitrogen adsorption on karst underground river sediments doesn't have good correspondence with the type of sediments. One of the reasons is there is no big difference between sediments in the development of climate, geology, hydrological conditions

  16. U.S. Geological Survey Subsidence Interest Group conference, Edwards Air Force Base, Antelope Valley, California, November 18-19, 1992; abstracts and summary

    Science.gov (United States)

    Prince, Keith R.; Galloway, Devin L.; Leake, Stanley A.

    1995-01-01

    with this unprecedented increase in pumpage, substantial amounts of land subsidence were observed in several areas of the United States, most notably in Arizona, California, and Texas. Beginning in 1955, under the direction of Joseph Poland, the Geological Survey began the "Mechanics of Aquifers Project," which focused largely on the processes that resulted in land subsidence due to the withdrawal of ground water. This research team gained international renown as they advanced the scientific understanding of aquifer mechanics and land-subsidence theory. The results of field studies by members of this research group not only verified the validity of the application of Terzaghi's consolidation theory to compressible aquifers, but they also provided definitions, methods of quantification, and confirmation of the interrelation among hydraulic head declines, aquifer-system compaction, and land subsidence. In addition to conducting pioneering research, this group also formed a "center of expertise," providing a focal point within the Geological Survey for the dissemination of technology and scientific understanding in aquifer mechanics. However, when the "Mechanics of Aquifers Project" was phased out in 1984, the focal point for technology transfer no longer existed. Interest among various state and local agencies in land subsidence has persisted, and the Geological Survey has continued to participate in a broad spectrum of cooperative and Federally funded projects in aquifer mechanics and land subsidence. These projects are designed to identify and monitor areas with the potential for land subsidence, to conduct basic research in the processes that control land subsidence and the development of earth fissures, as well as to develop new quantitative tools to predict aquifer-system deformation. In 1989 an ad hoc "Aquifer Mechanics and Subsidence Interest Group" (referred to herein as the "Subsidence Interest Group") was formed

  17. Response of the Karst Phreatic Zone to Flood Events in a Major River (Bohemian Karst, Czech Republic) and its Implication for Cave Genesis

    Czech Academy of Sciences Publication Activity Database

    Vysoká, H.; Bruthans, J.; Žák, Karel; Mls, J.

    2012-01-01

    Roč. 74, č. 1 (2012), s. 65-81 ISSN 1090-6924 R&D Projects: GA ČR GAP210/10/1760 Institutional research plan: CEZ:AV0Z30130516 Keywords : karst * cave genesis * Bohemian Karst Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.474, year: 2012

  18. Development of Landscape Architecture through Geo-eco-tourism in Tropical Karst Area to Avoid Extractive Cement Industry for Dignified and Sustainable Environment and Life

    Science.gov (United States)

    Cahyanti, Pita A. B.; Agus, Cahyono

    2017-08-01

    Karst areas in Indonesia amounted to 154,000 km2, potentially for extractive cement and wall paint industries. Exploitation of karst caused serious problems on the environment, health and social culture of the local community. Even though, karst region as a natural and cultural world heritage also have potential environmental services such as water resources, carbon sink, biodiversity, unique landscapes, natural caves, natural attractions, archaeological sites and mystic areas. Landscape architectural management of in the concept of blue revolution through the empowerment of land resources (soil, water, minerals) and biological resources (plant, animal, human), not only have adding value of economy aspect but also our dignified and sustainable environment and life through health, environmental, social, cultural, technological and management aspects. Geo-eco-tourism offers the efficiency of investment, increased creative innovation, increased funding, job creation, social capital development, stimulation of the socio-entrepreneurship in community. Community based geo-eco-tourism in Gunung Kidul Yogyakarta rapidly growing lately due to the local government banned the exploitation of karst. Landscape architecture at the caves, white sand beaches, cliffs in karst areas that beautiful, artistic and have special rare natural architecture form of stalactite and stalagmite, become the new phenomenal interested object of geo-eco-tourism. Many hidden nature objects that had been deserted and creepy could be visited by many local and foreign tourists. Landscape architectural management on hilltops with a wide view of the universe and fresh, sunset and sunrise, the clouds country are a rare sight for modern community. Local cultural attractions, local culinary, home stay with local communities will be an added attraction, but the infrastructure and human resources should be developed. Traveler photographs that widespread rapidly through social media and mass media became a

  19. A new species of karst-adapted Cnemaspis Strauch, 1887 (Squamata: Gekkonidae) from a threatened karst region in Pahang, Peninsular Malaysia.

    Science.gov (United States)

    Grismer, L Lee; Wood, Perry L; Mohamed, Maketab; Chan, Kin Onn; Heinz, Heather M; Sumarli, Alex S-I; Chan, Jacob A; Loredo, Ariel I

    2013-12-12

    A new species of karst-adapted gekkonid lizard of the genus Cnemaspis Strauch is described from Gua Gunting and Gua Goyang in a karst region of Merapoh, Pahang, Peninsular Malaysia whose unique limestone formations are in immediate danger of being quarried. The new species differs from all other species of Cnemaspis based on its unique suite of morphological and color pattern characters. Its discovery underscores the unique biodiversity endemic to karst regions and adds to a growing list of karst-adapted reptiles from Peninsular Malaysia. We posit that new karst-adapted species endemic to limestone forests will continue to be discovered and these regions will harbor a significant percentage of Peninsular Malaysia's biodiversity and thusly should be conserved rather than quarried.

  20. Geological-geophysical techniques applied to urban planning in karst hazardous areas. Case study of Zaragoza, NE Spain

    Science.gov (United States)

    Pueyo Anchuela, O.; Soriano, A.; Casas Sainz, A.; Pocoví Juan, A.

    2009-12-01

    Industrial and urban growth must deal in some settings with geological hazards. In the last 50 years, the city of Zaragoza (NE Spain) has developed an increase of its urbanized area in a progression several orders higher than expected from its population increase. This fast growth has affected several areas around the city that were not usually used for construction. Maps of the Zaragoza city area at the end of the XIXth century and beginning of the XXth reveal the presence of karst hazards in several zones that can be observed in more modern data, as aerial photographs taken during a period ranging from 1927 to present. The urban and industrial development has covered many of these hazardous zones, even though potential risks were known. The origins of the karst problems are related to the solution of evaporites (mainly gypsum, glauberite and halite) that represent the Miocene substratum of the Zaragoza area underlying the Quaternary terraces and pediments related to the Ebro River and its tributaries. Historical data show the persistence of subsidence foci during long periods of time while in recent urbanized areas this stability is not shared, observing the increase of activity and/or radius affection in short periods of time after building over. These problems can be related to two factors: i) urban development over hazardous areas can increase the karst activity and ii) the affection radius is not properly established with the commonly applied methods. One way to develop these detailed maps can be related to the geophysical approach. The applied geophysical routine, dependent on the characteristics of the surveyed area, is based on potential geophysical techniques (magnetometry and gravimetry) and others related to the application of induced fields (EM and GPR). The obtained results can be related to more straightforward criteria as the detection of cavities in the subsoil and indirect indicators related to the long-term activity of the subsidence areas

  1. An experimental study on the effects of exhaust gas on spruce (Picea abies L. Karst.)

    Energy Technology Data Exchange (ETDEWEB)

    Hautala, E.L.; Holopainen, J.; Kaerenlampi, L. [Kuopio Univ. (Finland). Dept. of Ecology and Environmental Science; Surakka, J.; Ruuskanen, J. [Kuopio Univ. (Finland). Dept. of Environmental Sciences

    1995-12-31

    Motor vehicle exhausts are significant contributors to air pollution. Besides fine particles and inorganic gases, like CO, SO{sub 2} and NO{sub x}, exhaust gas contains a large group of aromatic hydrocarbon compounds, many of which are phytotoxic. In field studies, exhausts are found to have both direct and indirect harmful effects on roadside plants. However, only few experimental studies have been made about the effects of exhaust gas emissions on coniferous trees. The aim of this study was to survey the effects of exhausts on spruce (Picea abies L. Karst.) in standardized conditions. The concentrations of major exhaust gas components in the chamber atmosphere were detected simultaneously. The effects of exhaust on epistomatal waxes of first-year spruce needles are described. (author)

  2. An experimental study on the effects of exhaust gas on spruce (Picea abies L. Karst.)

    Energy Technology Data Exchange (ETDEWEB)

    Hautala, E L; Holopainen, J; Kaerenlampi, L [Kuopio Univ. (Finland). Dept. of Ecology and Environmental Science; Surakka, J; Ruuskanen, J [Kuopio Univ. (Finland). Dept. of Environmental Sciences

    1996-12-31

    Motor vehicle exhausts are significant contributors to air pollution. Besides fine particles and inorganic gases, like CO, SO{sub 2} and NO{sub x}, exhaust gas contains a large group of aromatic hydrocarbon compounds, many of which are phytotoxic. In field studies, exhausts are found to have both direct and indirect harmful effects on roadside plants. However, only few experimental studies have been made about the effects of exhaust gas emissions on coniferous trees. The aim of this study was to survey the effects of exhausts on spruce (Picea abies L. Karst.) in standardized conditions. The concentrations of major exhaust gas components in the chamber atmosphere were detected simultaneously. The effects of exhaust on epistomatal waxes of first-year spruce needles are described. (author)

  3. Karst: Ditambang atau Dilestarikan, Konflik Sosial Rencana Pembangunan Pabrik Semen di Kabupaten Pati Jawa Tengah

    Directory of Open Access Journals (Sweden)

    - Suharko

    2015-01-01

    Full Text Available The establishment of cement industry at regions with rich content of karst has increasingly grown in recent years. As a consequence, conflict of interest between cement company and local people groups has arised. The article aims to mapping out a natural resource based-conflict in district of Pati, province of Jawa Tengah. The social conflict has taken place at the stage of pra-construction of cement plant in the south Pati. The cement company, supported by local government, has continuously tried to establish the plant. The local people groups have always rejected it. Through organizing indigenous people, building social networks, and undertaking various collective actions, the local people groups have refused any efforts for establishing the plant. While this social conflict has continued, so far there is no an adequate conflict resolution. However, the new government of Central Java resulted from the 2013 election provides an opportunity to end the conflict.

  4. Assessment of vulnerability in karst aquifers using a quantitative integrated numerical model: catchment characterization and high resolution monitoring - Application to semi-arid regions- Lebanon.

    Science.gov (United States)

    Doummar, Joanna; Aoun, Michel; Andari, Fouad

    2016-04-01

    Karst aquifers are highly heterogeneous and characterized by a duality of recharge (concentrated; fast versus diffuse; slow) and a duality of flow which directly influences groundwater flow and spring responses. Given this heterogeneity in flow and infiltration, karst aquifers do not always obey standard hydraulic laws. Therefore the assessment of their vulnerability reveals to be challenging. Studies have shown that vulnerability of aquifers is highly governed by recharge to groundwater. On the other hand specific parameters appear to play a major role in the spatial and temporal distribution of infiltration on a karst system, thus greatly influencing the discharge rates observed at a karst spring, and consequently the vulnerability of a spring. This heterogeneity can only be depicted using an integrated numerical model to quantify recharge spatially and assess the spatial and temporal vulnerability of a catchment for contamination. In the framework of a three-year PEER NSF/USAID funded project, the vulnerability of a karst catchment in Lebanon is assessed quantitatively using a numerical approach. The aim of the project is also to refine actual evapotranspiration rates and spatial recharge distribution in a semi arid environment. For this purpose, a monitoring network was installed since July 2014 on two different pilot karst catchment (drained by Qachqouch Spring and Assal Spring) to collect high resolution data to be used in an integrated catchment numerical model with MIKE SHE, DHI including climate, unsaturated zone, and saturated zone. Catchment characterization essential for the model included geological mapping and karst features (e.g., dolines) survey as they contribute to fast flow. Tracer experiments were performed under different flow conditions (snow melt and low flow) to delineate the catchment area, reveal groundwater velocities and response to snowmelt events. An assessment of spring response after precipitation events allowed the estimation of the

  5. Investigation of bacterioplankton communities in aquatic karst pools in Bärenschacht cave of Bernese Oberland

    OpenAIRE

    Shabarova, T; Pernthaler, J

    2009-01-01

    Karst subterraneous aquifers are highly diverse in structure and very important in the formation of ground water, which is the main source of freshwater supply for a significant proportion of the world’s population. Microorganisms can play an important role in karstification, carbon cycle and element mobility, but so far little is known about the bacteria of aquatic karst ecosystems. In this study, karst pools with differing hydrology in the Bärenschacht cave of the Bernese Oberla...

  6. Sustainable development of agriculture in karst areas, South China

    Directory of Open Access Journals (Sweden)

    Linhua Song

    1999-01-01

    Full Text Available The exposed carbonate rocks aged from Sinian to Mid-Triassic Periods cover an area of 500,000 Km2 in south-west China. In karst areas with spectacular landscapes characterized by magnificent tower karst and conical karst, rare surface drainage systems and prevalent subsurface drainage systems, the environment is ecologically very fragile. The rapid increase of population, over deforested and cultivated lands, worsted the ecological system, causing a higher frequency of draught, flood and various disasters, backward economic development, low living standard of the people. In order to improve the sustainability of the agriculture the experience shows that the following operations should be adopted: (1 serious control of the population increase, emigration, extra labours and improvement of the environmental education of the local inhabitants; (2 terracing of the slopes (shi jala di as to improve the cultivated land quality, to preserve the water, soil and fertiliser and ameliorate the effective utilisation of the land; (3 development of new rural energies such as the solar energy and gas energy, and expansion of the saving-fuel stoves to reduce the load of bio-energy; (4 reforestation and bounding the hills and mountains; the ecological, economic and fuel forests model has been developed in fengcong-depression areas: the tree species with high ecological, economical and energetic characteristics, should be chosen, such as the bamboo, wild grapes, Sapium rotundifolium etc.; (5 better utilisation of the ram water and karst water resource to solve the water supply problems. The karst landscape is well developed in the 500,000 km2 carbonate terrain in Yunnan, Guizhou, Guangxi, west Hunan and south Sichuan provinces in south-west China, where 100 million habitants live (Song, 1997. The large population and its high density, serious deforestation, over-cultivation and fragile ecological system make the environmental problems very serious and about 30

  7. Gaps in Political Interest

    DEFF Research Database (Denmark)

    Robison, Joshua

    2015-01-01

    Political interest fundamentally influences political behavior, knowledge, and persuasion (Brady, Verba, & Schlozman, 1995; Delli Carpini & Keeter, 1996; Luskin, 1990; Zukin, Andolina, Keeter, Jenkins, & Delli Carpini, 2006). Since the early 1960s, the American National Election Studies (ANES) has...... sought to measure respondents’ general interest in politics by asking them how often they follow public affairs. In this article, we uncover novel sources of measurement error concerning this question. We first show that other nationally representative surveys that frequently use this item deliver...... drastically higher estimates of mass interest. We then use a survey experiment included on a wave of the ANES’ Evaluating Government and Society Surveys (EGSS) to explore the influence of question order in explaining this systemic gap in survey results. We show that placing batteries of political...

  8. Study on comprehensive planning of rocky desertification in karst area of Chongqing

    Science.gov (United States)

    Zang, Yajun

    2017-11-01

    Chongqing is a key area for comprehensive treatment of rocky desertification in karst areas of china. Strengthening the comprehensive management of karst rocky desertification area, for the maintenance of ecological safety of Three Gorges Reservoir area, expanding the karst rocky desertification area people survival and development space, and improving the regional ecological conditions, have important practical significance to the construction of ecological civilization and building a harmonious society. Based on the investigation, analysis and arrangement of the data in the rocky desertification area, the paper puts forward the corresponding measures and phased targets for the treatment of the Rocky Desertification in the karst areas of Chongqing.

  9. Inventory of karst subsidence in the Valley and Ridge Province of East Tennessee

    International Nuclear Information System (INIS)

    Ketelle, R.H.; Newton, J.G.

    1986-01-01

    The first regional inventory of karst activity in the Valley and Ridge Province of East Tennessee was performed as a part of ongoing studies at Oak Ridge National Laboratory pertaining to environmental impact assessment of waste disposal in karst settings. More than half the land area in the Valley and Ridge Province of East Tennessee is underlain by karst-prone carbonate bedrock. The regional karst inventory was initiated to obtain current information on the extent of active karst subsidence in the region for use in decision making by the Department of Energy in planning future waste disposal facilities at Oak Ridge, Tennessee. The inventory was performed by contacting personnel of federal, state, and county agencies to obtain reports of known active karst subsidence within the region. Data from these interviews were tabulated resulting in identificaton of more than 250 karst subsidence incidents in East Tennessee, most of which have occurred since 1980. Although the infomation obtained was largely anecdotal, approximate location, date, size, and circumstances under which the collapses occurred were recorded for as many cases as could be documented. The study also included detailed reconnaissance of selected areas similar in geology and hydrology to a study area at Oak Ridge, Tennessee to identify causative factors which contribute to karst subsidence in the region and for comparison of the occurrence of visible karst features at different sites. Human activities affecting site hydrology such as large scale land clearing and earthmoving projects were related to most of the subsidence incidents inventoried

  10. Reduction of risk level as one of the main challenges of development in covered karst regions

    Directory of Open Access Journals (Sweden)

    Makhnatov Stanislav A.

    2013-01-01

    Full Text Available The paper describes the experience of application of the residual karst risk concept, and presents coefficients of karst risk level reduction for planning constructional karst-protection. Practical experience of design for karstified territories of Nizhny Novgorod region demonstrates that special research of the interaction between constructions and foundations is required. Numerous accidents can serve vivid examples proving the need. I2n this situation it is important to approach the issue of safety in a proper way, taking into account probable economic, environmental and social damage. The problem can be solved by introduction of the karst risk level parameter, which permits to take into consideration constructional characteristics of objects (design philosophy, service life, as well as conditions and mechanisms of interaction between the foundation and the construction (sinkholes, local subsidence, karst-suffosion deformations, etc.. The importance of risk reduction is highlighted by current Russian Federal laws. Depending on karst risk level adequate karst-protection should be performed. For building projects, reduction of karst risk to a permissible level (conventionally equal to 1 is one of the most important research challenges of the karstified territories development, and its solution permits to plan appropriate karst protection measures.

  11. Exposure to advertising and perception, interest, and use of e-cigarettes among adolescents: findings from the US National Youth Tobacco Survey.

    Science.gov (United States)

    Pu, Jia; Zhang, Xiao

    2017-11-01

    US adolescents are exposed to high levels of advertisements for electronic cigarettes (e-cigarettes). This study aimed to examine the associations between exposure to e-cigarette advertisements and perception, interest, and use of e-cigarettes among US middle school and high school students. Data from the 2014 cross-sectional National Youth Tobacco Survey were used. Logistic regressions were conducted to model four outcomes, including perception of reduced harmfulness compared to regular cigarettes, perception of reduced addictiveness, intention to use, and current use of e-cigarettes. Main predictors were exposure to e-cigarette advertisements via four sources, including Internet, newspaper/magazines, retail stores, and TV. When all the four sources of e-cigarette advertisements exposure were evaluated jointly, exposure via the Internet was associated with elevated likelihood of reporting all four outcomes related to e-cigarettes, while exposure via retail stores was associated with higher likelihood of current e-cigarette use and perception of reduced harmfulness of e-cigarettes compared to regular cigarettes ( p newspaper/magazines and TV was associated with lower likelihood of perceiving e-cigarettes to be less harmful or addictive ( p advertisements via the Internet and retail stores may play a significant role in adolescents' use and perception of e-cigarettes. The results call for more research on the influence of different sources of advertising exposure on e-cigarette use to help public health programmes curtail the fast growing use of e-cigarette products among youth.

  12. Physical Therapists in Primary Care Are Interested in High Quality Evidence Regarding Efficacy of Therapeutic Ultrasound for Knee Osteoarthritis: A Provincial Survey

    Directory of Open Access Journals (Sweden)

    Norma J. MacIntyre

    2013-01-01

    Full Text Available Recent high-level evidence favours therapeutic ultrasound (US for reducing pain in people with knee osteoarthritis (OA. It is unknown how current practice patterns align with current evidence regarding US efficacy and whether physical therapists perceive a need for further high-level evidence. We conducted a descriptive electronic survey to characterize the beliefs and use of US among physical therapists in Ontario treating people with nonsurgical knee OA. Most of the 123 respondents (81% reported at least some use of US with 45% using it often or sometimes. The main goal for using US was to reduce pain in the surrounding soft tissue (n=66 and/or the knee joint (n=43. Almost half (46% endorsed the belief that US is likely to be beneficial for clients with nonsurgical knee OA. Most respondents (85% expressed interest in the results of a randomized controlled trial evaluating the effectiveness of US on pain and physical function. Patterns of use reflect the respondents’ belief that US is likely to be beneficial for knee OA pain.

  13. Chemical erosion and hydrologic budget for the Susure karst plateau

    Directory of Open Access Journals (Sweden)

    Nikić Zoran

    2010-01-01

    Full Text Available The karst plateau of Susure, about 4.5 km2 in surface area, is situated on the Jadovnik eastern offset, western Serbia. The plateau is a morphologic unit higher 15 m to 30 m than the surrounding terrain. The unit consists of crushed and karstified Middle Triassic limestones. Numerous hydrogeological and geomorphologic features of the plateau are attractive for visitors in this economically underdeveloped country. Rocks building up the surrounding terrain are largely peridotites. Surface streams flow neither into nor off the plateau. Atmospheric precipitations discharge to evapotanspiration and filtration underground. More than eighteen constant springs at the limestone/peridotite tectonic contact drain fracture aquifers on the karst plateau border. Measured precipitations and springflows were the input and output data for accounting water budget of an aquifer of Middle Triassic limestones in the Susure plateau.

  14. Some cases of terrain unstability from the Dolenjska karst area

    Directory of Open Access Journals (Sweden)

    Magda Čarman

    2010-12-01

    Full Text Available The paper presents some cases of terrain unstability from the Dolenjska karst area formed in the last yearsaround Žužemberk and Dolenjske Toplice. The Dolenjska karst has its own characteristic way of development. Themain features are thick soil top, mainly composed of clay, and high and strongly fluctuating water table. Presentedare a landslide, two rockfalls and a sinkhole collapse. A landslide nearby Žužemberk was initiated in soil top. Bothrockfalls appeared in tectonically highly disturbed carbonate rocks along the Žužemberk fault. The sinkhole collapsein the area around Dolenjske Toplice developed in tectonically damaged rocks inside the Dolenjska - Notranjskahorst and during a period of heavy rain.

  15. Evaluating Weather Research and Forecasting Model Sensitivity to Land and Soil Conditions Representative of Karst Landscapes

    Science.gov (United States)

    Johnson, Christopher M.; Fan, Xingang; Mahmood, Rezaul; Groves, Chris; Polk, Jason S.; Yan, Jun

    2018-03-01

    Due to their particular physiographic, geomorphic, soil cover, and complex surface-subsurface hydrologic conditions, karst regions produce distinct land-atmosphere interactions. It has been found that floods and droughts over karst regions can be more pronounced than those in non-karst regions following a given rainfall event. Five convective weather events are simulated using the Weather Research and Forecasting model to explore the potential impacts of land-surface conditions on weather simulations over karst regions. Since no existing weather or climate model has the ability to represent karst landscapes, simulation experiments in this exploratory study consist of a control (default land-cover/soil types) and three land-surface conditions, including barren ground, forest, and sandy soils over the karst areas, which mimic certain karst characteristics. Results from sensitivity experiments are compared with the control simulation, as well as with the National Centers for Environmental Prediction multi-sensor precipitation analysis Stage-IV data, and near-surface atmospheric observations. Mesoscale features of surface energy partition, surface water and energy exchange, the resulting surface-air temperature and humidity, and low-level instability and convective energy are analyzed to investigate the potential land-surface impact on weather over karst regions. We conclude that: (1) barren ground used over karst regions has a pronounced effect on the overall simulation of precipitation. Barren ground provides the overall lowest root-mean-square errors and bias scores in precipitation over the peak-rain periods. Contingency table-based equitable threat and frequency bias scores suggest that the barren and forest experiments are more successful in simulating light to moderate rainfall. Variables dependent on local surface conditions show stronger contrasts between karst and non-karst regions than variables dominated by large-scale synoptic systems; (2) significant

  16. Sediment carbon fate in phreatic karst (Part 1): Conceptual model development

    Science.gov (United States)

    Husic, A.; Fox, J.; Agouridis, C.; Currens, J.; Ford, W.; Taylor, C.

    2017-06-01

    Recent research has paid increased attention to quantifying the fate of carbon pools within fluvial networks, but few, if any, studies consider the fate of sediment organic carbon in fluviokarst systems despite that karst landscapes cover 12% of the earth's land surface. The authors develop a conceptual model of sediment carbon fate in karst terrain with specific emphasis upon phreatic karst conduits, i.e., those located below the groundwater table that have the potential to trap surface-derived sediment and turnover carbon. To assist with their conceptual model development, the authors study a phreatic system and apply a mixture of methods traditional and novel to karst studies, including electrical resistivity imaging, well drilling, instantaneous velocimetry, dye tracing, stage recording, discrete and continuous sediment and water quality sampling, and elemental and stable carbon isotope fingerprinting. Results show that the sediment transport carrying capacity of the phreatic karst water is orders of magnitude less than surface streams during storm-activated periods promoting deposition of fine sediments in the phreatic karst. However, the sediment transport carrying capacity is sustained long after the hydrologic event has ended leading to sediment resuspension and prolonged transport. The surficial fine grained laminae occurs in the subsurface karst system; but unlike surface streams, the light-limited conditions of the subsurface karst promotes constant heterotrophy leading to carbon turnover. The coupling of the hydrological processes leads to a conceptual model that frames phreatic karst as a biologically active conveyor of sediment carbon that recharges degraded organic carbon back to surface streams. For example, fluvial sediment is estimated to lose 30% of its organic carbon by mass during a one year temporary residence within the phreatic karst. It is recommended that scientists consider karst pathways when attempting to estimate organic matter stocks

  17. Transport of free and particulate-associated bacteria in karst

    Science.gov (United States)

    Mahler, B. J.; Personné, J.-C.; Lods, G. F.; Drogue, C.

    2000-12-01

    Karst aquifers, because of their unique hydrogeologic characteristics, are extremely susceptible to contamination by pathogens. Here we present the results of an investigation of contamination of a karst aquifer by fecal indicator bacteria. Two wells intercepting zones with contrasting effective hydraulic conductivities, as determined by pump test, were monitored both during the dry season and in response to a rain event. Samples were also collected from the adjacent ephemeral surface stream, which is known to be impacted by an upstream wastewater treatment plant after rainfall. Whole water and suspended sediment samples were analyzed for fecal coliforms and enterococci. During the dry season, pumping over a 2-day period resulted in increases in concentrations of fecal coliforms to greater than 10,000 CFU/100 ml in the high-conductivity well; enterococci and total suspended solids also increased, to a lesser degree. Toward the end of the pumping period, as much as 50% of the fecal coliforms were associated with suspended sediment. Irrigation of an up-gradient pine plantation with primary-treated wastewater is the probable source of the bacterial contamination. Sampling after a rain event revealed the strong influence of water quality of the adjacent Terrieu Creek on the ground water. Bacterial concentrations in the wells showed a rapid response to increased concentrations in the surface water, with fecal coliform concentrations in ground water ultimately reaching 60,000 CFU/100 ml. Up to 100% of the bacteria in the ground water was associated with suspended sediment at various times. The results of this investigation are evidence of the strong influence of surface water on ground water in karst terrain, including that of irrigation water. The large proportion of bacteria associated with particulates in the ground water has important implications for public health, as bacteria associated with particulates may be more persistent and more difficult to inactivate. The

  18. Selected Micropollutants as Indicators in a Karst Catchment

    Science.gov (United States)

    Zirlewagen, Johannes; Schiperski, Ferry; Hillebrand, Olav; Nödler, Karsten; Licha, Tobias; Scheytt, Traugott

    2015-04-01

    High flow dynamics and variations in water quality are typical for karst springs and reflect the complex interaction of different flow and storage components within a karst system. Event-based monitoring of mobile micropollutants in spring water combined with information on their input is used (1) to quantify the impact of certain contamination scenarios on spring water quality and (2) to gain additional information on the intrinsic characteristics of a karst system. We employ the artificial sweeteners acesulfame and cyclamate as source specific indicators for sewage along with the herbicides atrazine and isoproturon for agriculture. The study site is the 45 km² rural catchment of the perennial karst spring Gallusquelle in SW-Germany (mean discharge: 0.5 m³/s). Overflow events of a stormwater detention basin (SDB, combined sewer system) are known to impact water quality. Most of the sewer system is situated in the SW of the catchment. Most agricultural land is found in the NE. Neither atrazine nor significant amounts of isoproturon were detected in wastewater. Concentrations and mass fluxes of acesulfame and cyclamate in wastewater were determined. The combined evaluation of the persistent compound acesulfame with the rather degradable cyclamate allows for the distinction of long and short transit times and thus slow and fast flow components. The same applies for atrazine (persistent) and isoproturon (degradable). In Germany, acesulfame was licensed in 1990, atrazine was banned shortly after, in 1991. During low flow conditions only atrazine (max. 4 ng/L) and acesulfame (max. 20 ng/L) were detected in spring water. After a recharge event without SDB overflow concentrations as well as mass fluxes of both compounds decreased, reflecting an increasing portion of event water in spring discharge. A breakthrough of isoproturon (max. 9 ng/L) indicated the arrival of water from croplands. After a recharge event accompanied by a SDB overflow cyclamate was detected at max

  19. Field observations of extended seawater intrusion through subsurface karst conduit networks at Wakulla Spring in the Woodville Karst Plain, Florida

    Science.gov (United States)

    Xu, Z.; Bassett, S.; Hu, B. X.; Dyer, S.

    2016-12-01

    Five periods of increased electrical conductivity have been found in the karst conduits supplying one of the largest first magnitude springs in Florida with water. Numerous well-developed conduit networks are distributed in the Woodville Karst Plain (WKP), Florida and connected to the Gulf of Mexico. A composite analysis of precipitation and electric conductivity data provides strong evidence that the increases in conductivity are directly tied to seawater intrusion moving inland and traveling 14 miles against the prevailing regional hydraulic gradient from from Spring Creek Spring Complex (SCSC), a group of submarine springs at the Gulf Coast. A geochemical analysis of samples from the spring vent rules out anthropogenic contamination and upwelling regional recharge from the deep aquifer as sources of the rising conductivity. The interpretation is supported by the conceptual model established by prior researchers working to characterize the study area. This abstract documented the first and longest case of seawater intrusion in the WKP, and also indicates significant possibility of seawater contamination through subsurface conduit networks in a coastal karst aquifer.

  20. Understanding karst environments by thermo-hygrometric monitoring: preliminary results from the Cesi Mountain karst system (Central Italy

    Directory of Open Access Journals (Sweden)

    Lucio Di Matteo

    2016-06-01

    Full Text Available The understanding of karst systems is of paramount importance for the protection and valorisation of these environments. A multidisciplinary study is presented to investigate the possible interconnection between karst features of a karst area located in the south-western part of the Martani chain (Cesi Mountain, Central Italy. This hydrogeological structure contributes to recharge a deep regional aquifer. The latter feeds the high discharge and salinity Stifone springs. In the southwestern part of Martani chain, seven caves have been mapped, five of which are hosted in the Calcare Massiccio Formation. The analysis of thermo-hygrometric data collected since Autumn 2014 into the caves and those from external meteorological stations, showed the timing of the airflow inversion occurring on late winter/early spring and summer/ early autumn. Despite the complexity of the morphology of caves and of conceptual models of airflow pattern, these data seem to indicate that the monitored small caves could be interconnected to a considerably wider cave system. Data here presented coupled with the knowledge on hydrogeological and geological-structural setting of the limestone massif are useful to drive future speleological explorations, aiming to discover new large cavities and to better understand the water recharge process.

  1. Water resources management in karst aquifers - concepts and modeling approaches

    Science.gov (United States)

    Sauter, M.; Schmidt, S.; Abusaada, M.; Reimann, T.; Liedl, R.; Kordilla, J.; Geyer, T.

    2011-12-01

    Water resources management schemes generally imply the availability of a spectrum of various sources of water with a variability of quantity and quality in space and time, and the availability and suitability of storage facilities to cover various demands of water consumers on quantity and quality. Aquifers are generally regarded as suitable reservoirs since large volumes of water can be stored in the subsurface, water is protected from contamination and evaporation and the underground passage assists in the removal of at least some groundwater contaminants. Favorable aquifer properties include high vertical hydraulic conductivities for infiltration, large storage coefficients and not too large hydraulic gradients / conductivities. The latter factors determine the degree of discharge, i.e. loss of groundwater. Considering the above criteria, fractured and karstified aquifers appear to not really fulfill the respective conditions for storage reservoirs. Although infiltration capacity is relatively high, due to low storativity and high hydraulic conductivities, the small quantity of water stored is rapidly discharged. However, for a number of specific conditions, even karst aquifers are suitable for groundwater management schemes. They can be subdivided into active and passive management strategies. Active management options include strategies such as overpumping, i.e. the depletion of the karst water resources below the spring outflow level, the construction of subsurface dams to prevent rapid discharge. Passive management options include the optimal use of the discharging groundwater under natural discharge conditions. System models that include the superposition of the effect of the different compartments soil zone, epikarst, vadose and phreatic zone assist in the optimal usage of the available groundwater resources, while taking into account the different water reservoirs. The elaboration and implementation of groundwater protection schemes employing well

  2. SWAT-based streamflow and embayment modeling of Karst-affected Chapel branch watershed, South Carolina

    Science.gov (United States)

    Devendra Amatya; M. Jha; A.E. Edwards; T.M. Williams; D.R. Hitchcock

    2011-01-01

    SWAT is a GIS-based basin-scale model widely used for the characterization of hydrology and water quality of large, complex watersheds; however, SWAT has not been fully tested in watersheds with karst geomorphology and downstream reservoir-like embayment. In this study, SWAT was applied to test its ability to predict monthly streamflow dynamics for a 1,555 ha karst...

  3. Techniques to better understand complex epikarst hydrogeology and contaminant transport in telogenetic karst settings

    Science.gov (United States)

    The movement of autogenic recharge through the shallow epikarstic zone in soil-mantled karst aquifers is important in understanding recharge areas and rates, groundwater storage, and contaminant transport processes. The groundwater flow in agricultural karst areas, such as Kentucky’s Pennyroyal Plat...

  4. Karst bare slope soil erosion and soil quality: a simulation case study

    OpenAIRE

    Q. Dai; Z. Liu; H. Shao; Z. Yang

    2015-01-01

    The influence on soil erosion by different bedrock bareness ratios, different rainfall intensities, different underground pore fissure degrees and rainfall duration are researched through manual simulation of microrelief characteristics of karst bare slopes and underground karst crack construction in combination with artificial simulation of rainfall experiment. The results show that firstly, when the rainfall intensity is small (30 and 50 mm h−1), no ...

  5. Tracking changing X-ray contrast media application to an urban-influenced karst aquifer in the Wadi Shueib, Jordan

    International Nuclear Information System (INIS)

    Zemann, Moritz; Wolf, Leif; Grimmeisen, Felix; Tiehm, Andreas; Klinger, Jochen; Hötzl, Heinz; Goldscheider, Nico

    2015-01-01

    Sewage input into a karst aquifer via leaking sewers and cesspits was investigated over five years in an urbanized catchment. Of 66 samples, analyzed for 25 pharmaceuticals, 91% indicated detectable concentrations. The former standard iodinated X-ray contrast medium (ICM) diatrizoic acid was detected most frequently. Remarkably, it was found more frequently in groundwater (79%, median: 54 ng/l) than in wastewater (21%, 120 ng/l), which is supposed to be the only source in this area. In contrast, iopamidol, a possible substitute, spread over the aquifer during the investigation period whereas concentrations were two orders of magnitude higher in wastewater than in groundwater. Knowledge about changing application of pharmaceuticals thus is essential to assess urban impacts on aquifers, especially when applying mass balances. Since correlated concentrations provide conclusive evidence that, for this catchment, nitrate in groundwater rather comes from urban than from rural sources, ICM are considered useful tracers. - Highlights: • 5 year survey on pharmaceutical occurrence in an urban influenced karst catchment. • Continued occurrence of diatrizoic acid in 5 springs despite only few occurrences in possible sources like wastewater. • Iopamidol was observed to spread within the aquifer during the monitoring period. • Increasing pharmaceutical detection rates in springs correlate with increasing E. coli numbers and nitrate concentrations. • Correlation analysis of diatrizoic acid and nitrate reveal urban areas as most likely source of nitrate. - The paper discusses challenges of using pharmaceuticals as tracers by the example of diatrizoic acid which occurred at a higher frequency in a karst aquifer than in the wastewater source

  6. Operational tools to help stakeholders to protect and alert municipalities facing uncertainties and changes in karst flash floods

    Science.gov (United States)

    Borrell Estupina, V.; Raynaud, F.; Bourgeois, N.; Kong-A-Siou, L.; Collet, L.; Haziza, E.; Servat, E.

    2015-06-01

    Flash floods are often responsible for many deaths and involve many material damages. Regarding Mediterranean karst aquifers, the complexity of connections, between surface and groundwater, as well as weather non-stationarity patterns, increase difficulties in understanding the basins behaviour and thus warning and protecting people. Furthermore, given the recent changes in land use and extreme rainfall events, knowledge of the past floods is no longer sufficient to manage flood risks. Therefore the worst realistic flood that could occur should be considered. Physical and processes-based hydrological models are considered among the best ways to forecast floods under diverse conditions. However, they rarely match with the stakeholders' needs. In fact, the forecasting services, the municipalities, and the civil security have difficulties in running and interpreting data-consuming models in real-time, above all if data are uncertain or non-existent. To face these social and technical difficulties and help stakeholders, this study develops two operational tools derived from these models. These tools aim at planning real-time decisions given little, changing, and uncertain information available, which are: (i) a hydrological graphical tool (abacus) to estimate flood peak discharge from the karst past state and the forecasted but uncertain intense rainfall; (ii) a GIS-based method (MARE) to estimate the potential flooded pathways and areas, accounting for runoff and karst contributions and considering land use changes. Then, outputs of these tools are confronted to past and recent floods and municipalities observations, and the impacts of uncertainties and changes on planning decisions are discussed. The use of these tools on the recent 2014 events demonstrated their reliability and interest for stakeholders. This study was realized on French Mediterranean basins, in close collaboration with the Flood Forecasting Services (SPC Med-Ouest, SCHAPI, municipalities).

  7. Kajian Kerusakan Lingkungan Karst sebagai Dasar Pelestarian Sumberdaya Air (Kasus di DAS Bribin Hulu Kabupaten Gunung Kidul Daerah Istimewa Yogyakarta

    Directory of Open Access Journals (Sweden)

    Raras Endarto

    2016-09-01

    ABSTRACT Groundwater resources in Gunung Kidul Regency synonymous with underground system Bribin  (Bribin watershed. Reservoir Bribin 1, Bribin 2, and Seropan located in the Dadapayu village Semanu Sub-District utilize to comply needs of population  in Gunung Kidul Regency. Existance of Bribin Watershed is very important for continuance and welfare of population which must be managed sustainability. Environmental management in order to achieve sustainability of water resources was emphasized on water recharge, namely Bribin Watershed of upstream section. Identification extent of damage in Bribin Watershed into one of urgency things because the area as underground supplier into reservoir river of Bribin, Baron, and Seropan was utilized for the needs of population. Extent damage of karst is assessed based on morphology of karst basin. This research was conducted using field observations and literature studies related to condition os study area. Considered of  karst damage parameters, includes morphology change caused by mining, existance outlet basin, land cover, condition of springs, caves, and existance of building over the karst surface must be conducted assessment in extent of damage. Administratively, extent of damage karst is very high located in Kenteng, Karangasem, and Bedoyo Village, area of 922.27 hectares. The high levels of extent of damage karst is Ponjong, Sawahan, Sumbergiri Village, area of 9424.24 hectares. The high levels of extent of damage karst among others, existance of great mining, springs, and building over the karst surface. Efforts conservation and management strategies commits based on characteristic karst and regional. Karst management policy strategies based on characteristic karst was pressed in surface appearace(eksokarst. Karst management policy strategies based on regional are management karst area plan overall. Water resources management is related to existence of karst component (eksokarst, include management of springs

  8. East Chestnut Ridge hydrogeologic characterization: A geophysical study of two karst features

    International Nuclear Information System (INIS)

    1991-01-01

    Permitting and site selection activities for the proposed East Chestnut Ridge landfill, located on the Oak Ridge Reservation, have required additional hydrogeologic studies of two karst features. Geophysical testing methods were utilized for investigating these karst features. The objectives of the geophysical testing was to determine the feasibility of geophysical techniques for locating subsurface karst features and to determine if subsurface anomalies exist at the proposed landfill site. Two karst features, one lacking surface expression (sinkhole) but with a known solution cavity at depth (from previous hydrologic studies), and the other with surface expression were tested with surface geophysical methods. Four geophysical profiles, two crossing and centered over each karst feature were collected using both gravimetric and electrical resistivity techniques

  9. Field Investigation and Modeling Development for Hydrological and Carbon Cycles in Southwest Karst Region of China

    Science.gov (United States)

    Hu, X. B.

    2017-12-01

    It is required to understanding water cycle and carbon cycle processes for water resource management and pollution prevention and global warming influence in southwest karst region of China. Lijiang river basin is selected as our study region. Interdisciplinary field and laboratory experiments with various technologies are conducted to characterize the karst aquifers in detail. Key processes in the karst water cycle and carbon cycle are determined. Based on the MODFLOW-CFP model, new watershed flow and carbon cycle models are developed coupled subsurface and surface water flow models. Our study focus on the karst springshed in Mao village, the mechanisms coupling carbon cycle and water cycle are explored. This study provides basic theory and simulation method for water resource management and groundwater pollution prevention in China karst region.

  10. Identification, prediction, and mitigation of sinkhole hazards in evaporite karst areas

    Science.gov (United States)

    Gutierrez, F.; Cooper, A.H.; Johnson, K.S.

    2008-01-01

    Sinkholes usually have a higher probability of occurrence and a greater genetic diversity in evaporite terrains than in carbonate karst areas. This is because evaporites have a higher solubility and, commonly, a lower mechanical strength. Subsidence damage resulting from evaporite dissolution generates substantial losses throughout the world, but the causes are only well understood in a few areas. To deal with these hazards, a phased approach is needed for sinkhole identification, investigation, prediction, and mitigation. Identification techniques include field surveys and geomorphological mapping combined with accounts from local people and historical sources. Detailed sinkhole maps can be constructed from sequential historical maps, recent topographical maps, and digital elevation models (DEMs) complemented with building-damage surveying, remote sensing, and high-resolution geodetic surveys. On a more detailed level, information from exposed paleosubsidence features (paleokarst), speleological explorations, geophysical investigations, trenching, dating techniques, and boreholes may help in investigating dissolution and subsidence features. Information on the hydrogeological pathways including caves, springs, and swallow holes are particularly important especially when corroborated by tracer tests. These diverse data sources make a valuable database-the karst inventory. From this dataset, sinkhole susceptibility zonations (relative probability) may be produced based on the spatial distribution of the features and good knowledge of the local geology. Sinkhole distribution can be investigated by spatial distribution analysis techniques including studies of preferential elongation, alignment, and nearest neighbor analysis. More objective susceptibility models may be obtained by analyzing the statistical relationships between the known sinkholes and the conditioning factors. Chronological information on sinkhole formation is required to estimate the probability of

  11. Analysis of the maximum discharge of karst springs

    Science.gov (United States)

    Bonacci, Ognjen

    2001-07-01

    Analyses are presented of the conditions that limit the discharge of some karst springs. The large number of springs studied show that, under conditions of extremely intense precipitation, a maximum value exists for the discharge of the main springs in a catchment, independent of catchment size and the amount of precipitation. Outflow modelling of karst-spring discharge is not easily generalized and schematized due to numerous specific characteristics of karst-flow systems. A detailed examination of the published data on four karst springs identified the possible reasons for the limitation on the maximum flow rate: (1) limited size of the karst conduit; (2) pressure flow; (3) intercatchment overflow; (4) overflow from the main spring-flow system to intermittent springs within the same catchment; (5) water storage in the zone above the karst aquifer or epikarstic zone of the catchment; and (6) factors such as climate, soil and vegetation cover, and altitude and geology of the catchment area. The phenomenon of limited maximum-discharge capacity of karst springs is not included in rainfall-runoff process modelling, which is probably one of the main reasons for the present poor quality of karst hydrological modelling. Résumé. Les conditions qui limitent le débit de certaines sources karstiques sont présentées. Un grand nombre de sources étudiées montrent que, sous certaines conditions de précipitations extrêmement intenses, il existe une valeur maximale pour le débit des sources principales d'un bassin, indépendante des dimensions de ce bassin et de la hauteur de précipitation. La modélisation des débits d'exhaure d'une source karstique n'est pas facilement généralisable, ni schématisable, à cause des nombreuses caractéristiques spécifiques des écoulements souterrains karstiques. Un examen détaillé des données publiées concernant quatre sources karstiques permet d'identifier les raisons possibles de la limitation de l'écoulement maximal: (1

  12. Invasive vascular plant species of limnocrenic karst springs in Poland

    Science.gov (United States)

    Spałek, Krzysztof

    2015-04-01

    Natural water reservoirs are very valuable floristic sites in Poland. Among them, the most important for preservation of biodiversity of flora are limnocrenic karst springs. The long-term process of human pressure on habitats of this type caused disturbance of their biological balance. Changes in the water regime, industrial development and chemisation of agriculture, especially in the period of last two hundred years, led to systematic disappearance of localities of many plant species connected with rare habitats and also to appear numerous invasive plant species. They are: Acorus calamus, Echinocystis lobata, Elodea canadensis, Erechtites hieraciifolia, Impatiens glandulifera, Solidago canadensis, S. gigantea and S. graminifolia. Fielworks were conducted in 2010-2014.

  13. Sinkhole susceptibility in carbonate rocks of the Apulian karst (southern Italy)

    Science.gov (United States)

    Di Santo, Antonio; Fazio, Nunzio L.; Fiore, Antonio; Lollino, Piernicola; Luisi, Michele; Miccoli, Maria N.; Pagliarulo, Rosa; Parise, Mario; Perrotti, Michele; Pisano, Luca; Spalluto, Luigi; Vennari, Carmela; Vessia, Giovanna

    2016-04-01

    Apulia region, the foreland of the southern Italian Apennines, is made up of a 6-7 km-thick succession of Mesozoic shallow-water limestones and dolostones, locally covered by thin and discontinuous Tertiary and Quaternary carbonate and clastic deposits. Due to their long subaerial exposure, the Mesozoic carbonate bedrock recorded the development in the subsurface of a dense network of karst cavities, mostly controlled by tectonic discontinuities. As a result, a strong susceptibility to natural sinkholes has to be recorded in Apulia. In addition, the possibility of occurrence of other problems related to the high number of man-made cavities has to be added in the region. A great variety of different typologies of artificial cavities (mostly excavated in the Plio-Pleistocene soft calcarenites) is actually present, including underground quarries, worship sites, oil mills, civilian settlements, etc. Overall, 2200 natural and 1200 artificial cavities, respectively, have been so far surveyed in Apulia. Following the urban development in the last century in Apulia, many of these cavities lie nowadays below densely populated neighborhoods, roads or communication routes. These conditions are at the origin of the main geomorphological hazard for the human society in Apulia, which requires a careful evaluation, aimed at protecting and safeguarding the human life, and at providing the necessary information for a correct land use planning and management. The importance of the sinkhole hazard is further testified by the worrying increase in the number of events during the last 5-6 years. In response to these situations, joint research activities were started by the Institute of Research for Hydrological Protection of the National Research Council (CNR-IRPI) and the Basin Authority of Apulia, aimed at several goals, that include (but are not limited to) the collection of information on natural and anthropogenic sinkholes in Apulia, the implementation of numerical analyses for

  14. Karst of the Mid-Atlantic region in Maryland, West Virginia, and Virginia

    Science.gov (United States)

    Doctor, Daniel H.; Weary, David J.; Brezinski, David K.; Orndorff, Randall C.; Spangler, Lawrence E.; Brezinski, David K.; Halka, Jeffrey; Ortt, Richard A.

    2015-01-01

    The Mid-Atlantic region hosts some of the most mature karst landscapes in North America, developed in highly deformed rocks within the Piedmont and Valley and Ridge physiographic provinces. This guide describes a three-day excursion to examine karst development in various carbonate rocks by following Interstate 70 west from Baltimore across the eastern Piedmont, across the Frederick Valley, and into the Great Valley proper. The localities were chosen in order to examine the structural and lithological controls on karst feature development in marble, limestone, and dolostone rocks with an eye toward the implications for ancient landscape evolution, as well as for modern subsidence hazards. A number of caves will be visited, including two commercial caverns that reveal strikingly different histories of speleogenesis. Links between karst landscape development, hydrologic dynamics, and water resource sustainability will also be emphasized through visits to locally important springs. Recent work on quantitative dye tracing, spring water geochemistry, and groundwater modeling reveal the interaction between shallow and deep circulation of groundwater that has given rise to the modern karst landscape. Geologic and karst feature mapping conducted with the benefit of lidar data help reveal the strong bedrock structural controls on karst feature development, and illustrate the utility of geologic maps for assessment of sinkhole susceptibility.

  15. Investigation of Submarine Groundwater Discharge and Preferential Groundwater Flow-paths in a Coastal Karst Area using towed Marine and Terrestrial Electrical Resistivity

    Science.gov (United States)

    O'connell, Y.; Daly, E.; Duffy, G.; Henry, T.

    2012-12-01

    Large volumes of groundwater, containing nutrients and contaminants enter the coastal waters of southern Galway Bay on the west coast of Ireland through submarine groundwater discharge (SGD). The SGD occurs through karstified Carboniferous limestone in a major karst region comprising the Burren and Gort Lowlands. The Carboniferous limestones have experienced extensive dissolution resulting in the development of an underground network of conduits and fissures that define a trimodal groundwater flow pattern across the region. Groundwater discharge to the sea in this area is exclusively intertidal and submarine. Storage in the karst is limited and typical winter rainfall conditions result in the karst system becoming saturated. Temporary lakes (turloughs) form in lowlying areas and act as large reservoirs which provide storage to enable the transmission of the large volumes of water in the system to the sea. Between 2010 and 2012, terrestrial and shallow marine geophysical surveying has been undertaken to investigate preferential groundwater flow-paths and SGD locations in order to quantify the groundwater-seawater interactions in this coastal karst system. A report into the groundwater system of this karst region following a major flood event proposed a conceptual conduit model defined by extensive water tracing, water level monitoring, hydrochemical sampling, geological mapping and drilling. Limited information about the dimensions of the conduits was known. Electrical resistivity tomography (ERT) profiling to depths of 100m below ground level, with multiple array configurations, has been carried out to investigate the modes of groundwater flow in to and out of both temporary and permanent freshwater lakes in the system. Towed dipole-dipole profiles have been recorded to investigate conduits beneath a permanent lake exhibiting a tidal influence despite its location 5.5 km from the seashore. The ERT data indicates significant variations in subsurface resistivities

  16. State-space prediction of spring discharge in a karst catchment in southwest China

    Science.gov (United States)

    Li, Zhenwei; Xu, Xianli; Liu, Meixian; Li, Xuezhang; Zhang, Rongfei; Wang, Kelin; Xu, Chaohao

    2017-06-01

    Southwest China represents one of the largest continuous karst regions in the world. It is estimated that around 1.7 million people are heavily dependent on water derived from karst springs in southwest China. However, there is a limited amount of water supply in this region. Moreover, there is not enough information on temporal patterns of spring discharge in the area. In this context, it is essential to accurately predict spring discharge, as well as understand karst hydrological processes in a thorough manner, so that water shortages in this area could be predicted and managed efficiently. The objectives of this study were to determine the primary factors that govern spring discharge patterns and to develop a state-space model to predict spring discharge. Spring discharge, precipitation (PT), relative humidity (RD), water temperature (WD), and electrical conductivity (EC) were the variables analyzed in the present work, and they were monitored at two different locations (referred to as karst springs A and B, respectively, in this paper) in a karst catchment area in southwest China from May to November 2015. Results showed that a state-space model using any combinations of variables outperformed a classical linear regression, a back-propagation artificial neural network model, and a least square support vector machine in modeling spring discharge time series for karst spring A. The best state-space model was obtained by using PT and RD, which accounted for 99.9% of the total variation in spring discharge. This model was then applied to an independent data set obtained from karst spring B, and it provided accurate spring discharge estimates. Therefore, state-space modeling was a useful tool for predicting spring discharge in karst regions in southwest China, and this modeling procedure may help researchers to obtain accurate results in other karst regions.

  17. Water Flow in Karst Aquifer Considering Dynamically Variable Saturation Conduit

    Science.gov (United States)

    Tan, Chaoqun; Hu, Bill X.

    2017-04-01

    The karst system is generally conceptualized as dual-porosity system, which is characterized by low conductivity and high storage continuum matrix and high conductivity and quick flow conduit networks. And so far, a common numerical model for simulating flow in karst aquifer is MODFLOW2005-CFP, which is released by USGS in 2008. However, the steady-state approach for conduit flow in CFP is physically impractical when simulating very dynamic hydraulics with variable saturation conduit. So, we adopt the method proposed by Reimann et al. (2011) to improve current model, in which Saint-Venant equations are used to model the flow in conduit. Considering the actual background that the conduit is very big and varies along flow path and the Dirichlet boundary varies with rainfall in our study area in Southwest China, we further investigate the influence of conduit diameter and outflow boundary on numerical model. And we also analyze the hydraulic process in multi-precipitation events. We find that the numerical model here corresponds well with CFP for saturated conduit, and it could depict the interaction between matrix and conduit during very dynamic hydraulics pretty well compare with CFP.

  18. Associations between perceptions of e-cigarette advertising and interest in product trial amongst US adult smokers and non-smokers: results from an internet-based pilot survey

    OpenAIRE

    Smith, Danielle M.; Bansal-Travers, Maansi; O?Connor, Richard J.; Goniewicz, Maciej L.; Hyland, Andrew

    2015-01-01

    Background Electronic cigarettes (e-cigarettes) have risen in popularity in the U.S. While recent studies have described the prevalence and demographics of e-cigarette users, few studies have evaluated the impact of advertising on perceptions and interest in trial. This pilot study was conducted to assess whether exposure to ads for e-cigarettes or a comparison product (snus), elicited differences in interest to try e-cigarettes between smokers and non-smokers. Methods A web-based survey was ...

  19. Different interest group views of fuels treatments: survey results from fire and fire surrogate treatments in a Sierran mixed conifer forest, California, USA

    Science.gov (United States)

    Sarah McCaffrey; Jason J. Moghaddas; Scott L. Stephens

    2008-01-01

    The present paper discusses results from a survey about the acceptance of and preferences for fuels treatments of participants following a field tour of the University of California Blodgett Forest Fire and Fire Surrogate Study Site. Although original expectations were that tours would be composed of general members of the public, individual tour groups ultimately were...

  20. Characterizing fate and transport properties in karst aquifers under different hydrologic conditions

    Science.gov (United States)

    Rodriguez, E.; Padilla, I. Y.

    2017-12-01

    Karst landscapes contain very productive aquifers. The hydraulic and hydrogeological characteristics of karst aquifers make these systems capable of storing and transporting large amount of water, but also highly vulnerable to contamination. Their extremely heterogeneous nature prevents accurate prediction in contaminant fate and transport. Even more challenging is to understand the impact of hydrologic conditions changes on fate and transport processes. This studies aims at characterizing fate and transport processes in the karst groundwater system of northern Puerto Rico under different hydrologic conditions. The study involves injecting rhodamine and uranine dyes into a sinkhole, and monitoring concentrations at a spring. Results show incomplete recovery of tracers, but breaking curves can be used to estimate advective, dispersive and mass transfer characteristic of the karst system. Preliminary results suggest significant differences in fate and transport characteristics under different hydrologic conditions.

  1. The 'Umweltanwalt' as a means of 'indirect citizens participation' - A survey of possibilities of the representation of environmental interests in administrative procedures in Austrian law

    International Nuclear Information System (INIS)

    Schnedl, G.

    1990-11-01

    The central topic of this study is how environmental protection can be ensured within the framework of administrative procedures in Austria. Environmental law in Austria faces two major problems. One is the inadequacy of statutory law; the other a lack of execution. The reasons for the latter are examined in part I. The main part of the study discusses various ways of representing environmental protection interests in administrative procedures, such as licensing. As there are certain limits to citizen's individual rights the study focusses on the participation of groups of citizens and associations as well as ' indirect participation' through an institutionalized representative of environmental interests (a so called 'Umweltanwalt'). Part II gives a comparative analysis of the legal implementation of the 'Umweltanwalt' and similar institutions in Austria's 'Laender' (federal states); it also deals with the pros and cons of creating an 'Umweltanwalt' on the federal level. Part III is dedicated to a proposed amendment of the rules of administrative procedure providing for the participation of the public in environmental decision making. Part IV deals with the question if this procedural approach can be the basis of an appropriate environmental impact assessment. The final part summarizes the positive and negative aspects of the various instruments and pleads for their combination as a solution for the problem of underrepresentation of environmental interests in agency decision making. (author)

  2. The origin and evolution of the term "karst"%术语"Karst"的起源和演化

    Institute of Scientific and Technical Information of China (English)

    Andrej Kranjc

    2011-01-01

    对于术语“karst”的起源和演化,不少文献(包括手册、教科书、字典等)仍有不准确、不一致甚至错误的论述.鉴于此,本文不仅重述了众所周知的关于“karst”起源的事实,而且介绍了“karst”起源和演化的最新语言学研究结果.“karst”是由喀尔斯(Kras)高地的名称演化而来的.喀尔斯位于亚得里亚海的里雅斯特湾(Gulf of Trieste)达尔马提亚(Dalmatia)海岸地区,其大部分属于斯洛文尼亚.喀尔斯是一处海拔150~450 m,覆盖面积550 km2(长约40 km,宽约13 km)的碳酸盐岩高地.斯洛文尼亚语、意大利语和德语分别称之为Kras、Carso和Karst.喀尔斯高地表面大致平坦,但从局部看,喀斯特洼地遍布,各种典型的喀斯特地貌形态随处可见,包括坡立谷、大小溶斗(包括大的塌陷溶斗)、喀斯特干谷和溶洞.这些形态规模较小,起伏平缓.喀尔斯高地的名称起源于前罗马时期,其古典拉丁语名称(也是目前已知最早的名称)为Carsus.该词的词根* kar(u)S-是由意思为“石头或岩石”的词根*kar-演化而来.从欧洲众多文献中可以发现有许多名词来自前印欧语系的词根kar(r)a/gar(r)a.这些词根最初意思指石头或岩石,而后发展为石头筑成的遮盖物——一间房屋,一座城堡,甚至一个村落,这些词根还演化成喀斯特相关术语.由Carsus的宾格形式Carsum演变成现代意大利语名称Carso;同样的宾格依据前斯洛文尼亚语言规则(即r或l出现在元音和辅音字母之间时,须将其移至元音字母之前.)演变成Kras;德语Karst则是由意大利语Carso 依据德语变化规则(以s结束的单词末尾须添加t)演变而来.由此可见,Kras、Karst和Carso均源于古拉丁文Carsus,该词含有词根*kar(u)s-.印刷技术的改进和新大陆的发现,带动了地图和地图集的出版.喀尔斯高地的名称不仅出现在地方性地图上,而且被大尺度区域性地图所标示

  3. Process-based karst modelling to relate hydrodynamic and hydrochemical characteristics to system properties

    Directory of Open Access Journals (Sweden)

    A. Hartmann

    2013-08-01

    Full Text Available More than 30% of Europe's land surface is made up of karst exposures. In some countries, water from karst aquifers constitutes almost half of the drinking water supply. Hydrological simulation models can predict the large-scale impact of future environmental change on hydrological variables. However, the information needed to obtain model parameters is not available everywhere and regionalisation methods have to be applied. The responsive behaviour of hydrological systems can be quantified by individual metrics, so-called system signatures. This study explores their value for distinguishing the dominant processes and properties of five different karst systems in Europe and the Middle East. By defining ten system signatures derived from hydrodynamic and hydrochemical observations, a process-based karst model is applied to the five karst systems. In a stepwise model evaluation strategy, optimum parameters and their sensitivity are identified using automatic calibration and global variance-based sensitivity analysis. System signatures and sensitive parameters serve as proxies for dominant processes, and optimised parameters are used to determine system properties. By sensitivity analysis, the set of system signatures was able to distinguish the karst systems from one another by providing separate information about dominant soil, epikarst, and fast and slow groundwater flow processes. Comparing sensitive parameters to the system signatures revealed that annual discharge can serve as a proxy for the recharge area, that the slopes of the high flow parts of the flow duration curves correlate with the fast flow storage constant, and that the dampening of the isotopic signal of the rain as well as the medium flow parts of the flow duration curves have a non-linear relation to the distribution of groundwater storage constants that represent the variability of groundwater flow dynamics. Our approach enabled us to identify dominant processes of the

  4. Vegetation in karst terrain of southwestern China allocates more biomass to roots

    Science.gov (United States)

    Ni, J.; Luo, D. H.; Xia, J.; Zhang, Z. H.; Hu, G.

    2015-07-01

    In mountainous areas of southwestern China, especially Guizhou province, continuous, broadly distributed karst landscapes with harsh and fragile habitats often lead to land degradation. Research indicates that vegetation located in karst terrains has low aboveground biomass and land degradation that reduces vegetation biomass, but belowground biomass measurements are rarely reported. Using the soil pit method, we investigated the root biomass of karst vegetation in five land cover types: grassland, grass-scrub tussock, thorn-scrub shrubland, scrub-tree forest, and mixed evergreen and deciduous forest in Maolan, southern Guizhou province, growing in two different soil-rich and rock-dominated habitats. The results show that roots in karst vegetation, especially the coarse roots, and roots in rocky habitats are mostly distributed in the topsoil layers (89 % on the surface up to 20 cm depth). The total root biomass in all habitats of all vegetation degradation periods is 18.77 Mg ha-1, in which roots in rocky habitat have higher biomass than in earthy habitat, and coarse root biomass is larger than medium and fine root biomass. The root biomass of mixed evergreen and deciduous forest in karst habitat (35.83 Mg ha-1) is not greater than that of most typical, non-karst evergreen broad-leaved forests in subtropical regions of China, but the ratio of root to aboveground biomass in karst forest (0.37) is significantly greater than the mean ratio (0.26 ± 0.07) of subtropical evergreen forests. Vegetation restoration in degraded karst terrain will significantly increase the belowground carbon stock, forming a potential regional carbon sink.

  5. Factors Affecting Public-Supply Well Vulnerability in Two Karst Aquifers

    OpenAIRE

    Musgrove, MaryLynn; Katz, Brian G; Fahlquist, Lynne S; Crandall, Christy A; Lindgren, Richard J

    2014-01-01

    Karst aquifers occur in a range of climatic and geologic settings. Nonetheless, they are commonly characterized by their vulnerability to water-quality impairment. Two karst aquifers, the Edwards aquifer in south-central Texas and the Upper Floridan aquifer in western Florida, were investigated to assess factors that control the movement of contaminants to public-supply wells (PSWs). The geochemistry of samples from a selected PSW or wellfield in each aquifer was compared with that from nearb...

  6. Revison of an Atheloptic Visean Trilobite Association in the Moravian Karst (Czech Republic

    Directory of Open Access Journals (Sweden)

    Rak Štěpán

    2015-01-01

    Full Text Available Recently two new trilobite occurrences were discovered during geological mapping of fossiliferous shales of the Březina Formation around the village of Březina in the Moravian Karst (Czech Republic. The newly discovered localities are extraordinary because of the unexpected occurrence of articulated trilobite exoskeletons associated with brachiopods including supporting spines. The new atheloptic association of Mississippian trilobites is described for the first time from the Moravian Karst.

  7. Lignin distribution in waterlogged archaeological Picea abies (L.) Karst degraded by erosion bacteria

    DEFF Research Database (Denmark)

    Pedersen, Nanna Bjerregaard; Schmitt, Uwe Schmitt; Koch, Gerald

    2014-01-01

    The lignin distribution in poles of waterlogged archaeological Picea abies (L.) Karst, which was decayed by erosion bacteria (EB) under anoxic conditions for approximately 400 years, was topochemically identified by transmission electron microscopy (TEM) and high resolution UV-microspectrophotome......The lignin distribution in poles of waterlogged archaeological Picea abies (L.) Karst, which was decayed by erosion bacteria (EB) under anoxic conditions for approximately 400 years, was topochemically identified by transmission electron microscopy (TEM) and high resolution UV...

  8. Karst bare slope soil erosion and soil quality: a simulation case study

    OpenAIRE

    Q. Dai; Z. Liu; H. Shao; Z. Yang

    2015-01-01

    The influence on soil erosion by different bedrock bareness ratios, different rainfall intensities, different underground pore fissure degrees and rainfall duration are researched through manual simulation of microrelief characteristics of karst bare slopes and underground karst crack construction in combination with artificial simulation of rainfall experiment. The results show that firstly, when the rainfall intensity is small (30 and 50 mm h−1), no bottom load loss is pro...

  9. Pesticides and biocides in a karst catchment: Identification of contaminant sources and related flow components

    Science.gov (United States)

    Wagner, Thomas; Bollmann, Ulla E.; Bester, Kai; Birk, Steffen

    2013-04-01

    Karst aquifers are widely used as drinking water resources. However, their high vulnerability to chemical and bacterial contamination due to the heterogeneity in aquifer properties (highly conductive solution conduits embedded in the less conductive fissured rock) is difficult to assess and thus poses major challenges to the management of karst water resources. Contamination of karst springs by organic micro-pollutants has been observed in recent studies. Within this study the water from different springs draining one karst aquifer as well as the main sinking stream replenishing it were analysed before, during and after a storm water event in order to examine the occurrence of different pesticides and biocides. Contaminants from both urban as well as agricultural origin could be detected in the water with concentrations in the low ng/L range (tebuconazole, carbendazim, diuron, isoproturon, terbutryn, atrazine, dichlorobenzamide (BAM), which is a metabolite of dichlobenil). While some compounds could be followed from the sinking stream to the springs (e.g. dichlorobenzamide) some seem to have a source in the autogenic recharge from the karst plateau (Tebuconazole: wood preservative in buildings). These compounds appear to be related to fast flow components with residence times in the order of days, which are known from a number of tracer tests with fluorescent dyes. However, the occurrence of the pesticide atrazine (banned since 1995 in Austria) in the springs, while on the other hand no current input into the karst occurs, shows that some compounds have long residence times in the karst aquifer. These differences in residence times can hardly be attributed to differences in physico-chemical properties of the compounds and must thus be due to the presence of slow and fast flow components. This is in agreement with the duality of karst aquifers due to highly conductive networks of solution conduits embedded in less conductive fissured carbonate rocks.

  10. Simulating flow in karst aquifers at laboratory and sub-regional scales using MODFLOW-CFP

    Science.gov (United States)

    Gallegos, Josue Jacob; Hu, Bill X.; Davis, Hal

    2013-12-01

    Groundwater flow in a well-developed karst aquifer dominantly occurs through bedding planes, fractures, conduits, and caves created by and/or enlarged by dissolution. Conventional groundwater modeling methods assume that groundwater flow is described by Darcian principles where primary porosity (i.e. matrix porosity) and laminar flow are dominant. However, in well-developed karst aquifers, the assumption of Darcian flow can be questionable. While Darcian flow generally occurs in the matrix portion of the karst aquifer, flow through conduits can be non-laminar where the relation between specific discharge and hydraulic gradient is non-linear. MODFLOW-CFP is a relatively new modeling program that accounts for non-laminar and laminar flow in pipes, like karst caves, within an aquifer. In this study, results from MODFLOW-CFP are compared to those from MODFLOW-2000/2005, a numerical code based on Darcy's law, to evaluate the accuracy that CFP can achieve when modeling flows in karst aquifers at laboratory and sub-regional (Woodville Karst Plain, Florida, USA) scales. In comparison with laboratory experiments, simulation results by MODFLOW-CFP are more accurate than MODFLOW 2005. At the sub-regional scale, MODFLOW-CFP was more accurate than MODFLOW-2000 for simulating field measurements of peak flow at one spring and total discharges at two springs for an observed storm event.

  11. Identification of Hydrochemical Function and Behavior of the Houzhai Karst Basin, Guizhou Province, Southwestern China

    Directory of Open Access Journals (Sweden)

    Xian Li

    2018-01-01

    Full Text Available Due to the difference of geomorphology and the development of fractures, the hydrochemical function and behavior appear to be complex. Variations of karst water conductivity can reflect the contribution of different runoff sources and thus indirectly reflect the development characteristics of conduits and fractures. Taking Houzhai karst system (southwestern China as a case study, the frequency distribution curves of karst water conductivity were decomposed by Gaussian Mixture Analysis to identify the runoff components of different karst landform. The dominant runoff types had been distinguished, and the relative contribution of the different water types had been investigated. The results showed that the karst flow types were slope flow, rapid fracture flow, and slow fracture flow. Rapid fracture flow was the major recharge type of Houzhai karst water system. Slow fracture flow in the downstream area accounted for a larger proportion than that of the upstream area. The relative contribution of the different runoff components showed that the upstream area was a rapid flow area of conduit structure with low storage capacity, the downstream area was an aquifer spatial structure of netted fissure conduit with high storage capacity, and the midstream area was a transitional zone between the upstream and downstream area.

  12. Analysis of the karst aquifer structure of the Lamalou area (Herault, France) with ground penetrating radar

    International Nuclear Information System (INIS)

    Al-Fares, W.; Bakalowicz, M.; Guerin, R.; Dukhan, M.

    2004-01-01

    The study site at Lamalou karst spring Hortus karst plateau) is situated 40 km north of Montpellier in France. It consists of a limestone plateau, drained by a karst conduit discharging as a spring. This conduit extends for a few dozen meters in fractured and karstified limestone rocks, 15 to 70 m below the surface. The conduit is accessible from the surface. The main goal of this study is to analyze the surface part of the karst and to highlight the karstic features and among them the conduit, and to test the performances of ground penetrating radar (GPR) in a karstic environment. This method thus appears particularly well adapted to the analysis of the near-surface (<30 m in depth) structure of a karst, especially when clayey coating or soil that absorbs and attenuates the radar is rare and discontinuous. A GPR pulse EKKO 100 (Sensors and Software) was used on the site with a 50 MHz antenna frequency. The results highlight structures characterizing the karstic environment: The epikarst, bedding planes, fractured and karstified zones, compact and massive rock and karrens, a typical karst landform. One of the sections revealed in detail the main conduit located at a depth of 20 m, and made it possible to determine its geometry. This site offers possibilities of validation of GPR data by giving direct access to the karstic conduit and through two cored boreholes. These direct observations confirm the interpretation of all the GPR sections. (author

  13. Karst in the United States: a digital map compilation and database

    Science.gov (United States)

    Weary, David J.; Doctor, Daniel H.

    2014-01-01

    This report describes new digital maps delineating areas of the United States, including Puerto Rico and the U.S. Virgin Islands, having karst or the potential for development of karst and pseudokarst. These maps show areas underlain by soluble rocks and also by volcanic rocks, sedimentary deposits, and permafrost that have potential for karst or pseudokarst development. All 50 States contain rocks with potential for karst development, and about 18 percent of their area is underlain by soluble rocks having karst or the potential for development of karst features. The areas of soluble rocks shown are based primarily on selection from State geologic maps of rock units containing significant amounts of carbonate or evaporite minerals. Areas underlain by soluble rocks are further classified by general climate setting, degree of induration, and degree of exposure. Areas having potential for volcanic pseudokarst are those underlain chiefly by basaltic-flow rocks no older than Miocene in age. Areas with potential for pseudokarst features in sedimentary rocks are in relatively unconsolidated rocks from which pseudokarst features, such as piping caves, have been reported. Areas having potential for development of thermokarst features, mapped exclusively in Alaska, contain permafrost in relatively thick surficial deposits containing ground ice. This report includes a GIS database with links from the map unit polygons to online geologic unit descriptions.

  14. [Natural regeneration of young Excentrodendron hsienmu in karst mountainous region in Southwest Guangxi, China].

    Science.gov (United States)

    Ou, Zhi-Yang; Su, Zhi-Yao; Peng, Yu-Hua; Hu, Qin-Fei; Huang, Xiao-Rong

    2013-09-01

    A field survey was conducted in the karst mountainous region in Pingguo County of Southwest Guangxi, China to explore the structural characteristics, spatial distribution pattern, and growth dynamics of young Excentrodendron hsienmu as well as the main environmental factors affecting the natural regeneration of the E. hsienmu population. In the study area, the population structure of the young E. hsienmu was stable, and exhibited a clumped spatial pattern for the seedlings and seedling sprouts. The ground diameter growth and height growth of the young E. hsienmu presented the same variation trend, i. e., the ground diameter increased with increasing height. The ground diameter growth and height growth of the E. hsienmu seedlings were limited by population density, i. e., decreased with increasing population density. The correlation analysis showed that the trees more than 2.5 m in height and the shrubs were the major stand factors affecting the natural regeneration of young E. hsienmu, while the herbs had no significant correlation with the regeneration. The percentage of covered rock also had no significant effects on the regeneration. Kruskal-Wallis ANOVA showed that there existed significant differences in the height and ground diameter of young E. hsienmu at different slope degrees and slope positions. The population density, height, and ground diameter had significant differences across slope aspects. The natural regeneration of young E. hsienmu was comprehensively affected by the species biological characteristics, intraspecific competition, interspecific competition, heterogeneous habitat, and anthropogenic disturbances.

  15. Teaching resources in speleology and karst: a valuable educational tool

    Directory of Open Access Journals (Sweden)

    De Waele Jo

    2010-01-01

    Full Text Available There is a growing need in the speleological community of tools that make teaching of speleology and karst much easier. Despite the existence of a wide range of major academic textbooks, often the caver community has a difficult access to such material. Therefore, to fill this gap, the Italian Speleological Society, under the umbrella of the Union International de Spéléologie, has prepared a set of lectures, in a presentation format, on several topics including geology, physics, chemistry, hydrogeology, mineralogy, palaeontology, biology, microbiology, history, archaeology, artificial caves, documentation, etc. These lectures constitute the “Teaching Resources in Speleology and Karst”, available online. This educational tool, thanks to its easily manageable format, can constantly be updated and enriched with new contents and topics.

  16. Isotope study in the Alpine karst region of Rawil (Switzerland)

    International Nuclear Information System (INIS)

    Schotterer, U.; Siegenthaler, U.; Oeschger, H.; Wildberger, A.; Nabholz, W.

    1978-01-01

    An isotope study in the karst of the high Alps in Switzerland is described. From 1973 to 1978 discharge, 3 H, delta 18 O, conductivity and temperature were measured in representative springs. The springs are influenced by snowmelt in late spring and summer, by rain in late summer and autumn, and in the winter period, when infiltration stops, by reservoir water. Since tritium in precipitation in the last years scattered irregularly in time and space, the residence time of winter baseflow (2-4 years) could not be determined very precisely. The pronounced difference in delta 18 O between several springs allowed us to estimate the difference in mean altitude of their recharge areas. (orig.) [de

  17. Overexploitation of karst spring as a measure against water scarcity.

    Science.gov (United States)

    Dimkić, Dejan; Dimkić, Milan; Soro, Andjelko; Pavlović, Dusan; Jevtić, Goran; Lukić, Vladimir; Svrkota, Dragan

    2017-09-01

    Water scarcity, especially in the hydrologically critical part of the year, is a problem often present in many cities and regions, particularly in arid and sub-arid areas. Climate change and human water demand compound the problem. This paper discusses a climate change adaptation measure-the possibility of karst spring overexploitation, where there is a siphon-shaped cavity inside the mountain. The pilot area is near the city of Niš, where a decreasing precipitation trend has already been observed and is expected to continue in the future. The paper also presents some basic information related to the pilot area and undertaken investigations. The project, successfully implemented in 2004, has provided the city of Niš with an additional amount of 200 l/s of spring water during the most critical part of the year.

  18. About Fundamental Problems of Hydrosphere and Silicate Karst

    Directory of Open Access Journals (Sweden)

    A. Ya. Gayev

    2017-09-01

    Full Text Available Rationale of hydrosphere model with two regions of supply and discharge reveals regularities of ground water formation reflecting the special features of system water – rock – gas – living material and character of interaction of hydrosphere with the other spheres of the Earth. It is necessary to concentrate the development of endogenous hy-drogeology fundamentals with the study of silicate karst on investigation of “white and black smokers”, the structure and isotope composition of water in different phase condi-tions, and on modeling of situation in hydrometagenese zone. It will support the development of geotechnology and providing the humanity with mineral and energetic resources in future.

  19. Human impact on Karst: the example of Lusaka (Zambia.

    Directory of Open Access Journals (Sweden)

    De Waele Jo

    2003-01-01

    Full Text Available Lusaka, the capital of Zambia with over 2,000,000 inhabitants, is built on an extensive plateau composed mainly of schists and dolomitic marbles, constituting a very important aquifer that provides the city with almost half of its drinking water needs. Recent demographic growth, leading to uncontrolled urban expansion, and mismanagement of the water resource and of urban waste has lead, in the past 20 years, to an overexploitation of the aquifer and to a generalised water quality depletion, putting in serious danger the future social and economical development of the capital. This third world city has, for these reasons, become a terrifying example of human impact on a vulnerable karst environment, and if no measures will be taken in the very near future, quality of life in the city will be at serious risk.

  20. Resonance wood [Picea abies (L.) Karst.]--evaluation and prediction of violin makers' quality-grading.

    Science.gov (United States)

    Buksnowitz, Christoph; Teischinger, Alfred; Müller, Ulrich; Pahler, Andreas; Evans, Robert

    2007-04-01

    The definition of quality in the field of resonance wood for musical instrument making has attracted considerable interest over decades but has remained incomplete. The current work compares the traditional knowledge and practical experience of violin makers with a material-science approach to objectively characterize the properties of resonance wood. Norway spruce [Picea abies (L.) Karst.] has earned a very high reputation for the construction of resonance tops of stringed instruments and resonance boards of keyboard instruments, and was therefore chosen as the focus of the investigation. The samples were obtained from numerous renowned resonance wood regions in the European Alps and cover the whole range of available qualities. A set of acoustical, anatomical, mechanical and optical material properties was measured on each sample. These measurements were compared with subjective quality grading by violin makers, who estimated the acoustical, optical and overall suitability for violin making. Multiple linear regression models were applied to evaluate the predictability of the subjective grading using the measured material characteristics as predictors. The results show that luthiers are able to estimate wood quality related to visible features, but predictions of mechanical and acoustical properties proved to be very poor.

  1. Using nitrate to quantify quick flow in a karst aquifer

    Science.gov (United States)

    Mahler, B.J.; Garner, B.D.

    2009-01-01

    In karst aquifers, contaminated recharge can degrade spring water quality, but quantifying the rapid recharge (quick flow) component of spring flow is challenging because of its temporal variability. Here, we investigate the use of nitrate in a two-endmember mixing model to quantify quick flow in Barton Springs, Austin, Texas. Historical nitrate data from recharging creeks and Barton Springs were evaluated to determine a representative nitrate concentration for the aquifer water endmember (1.5 mg/L) and the quick flow endmember (0.17 mg/L for nonstormflow conditions and 0.25 mg/L for stormflow conditions). Under nonstormflow conditions for 1990 to 2005, model results indicated that quick flow contributed from 0% to 55% of spring flow. The nitrate-based two-endmember model was applied to the response of Barton Springs to a storm and results compared to those produced using the same model with ??18O and specific conductance (SC) as tracers. Additionally, the mixing model was modified to allow endmember quick flow values to vary over time. Of the three tracers, nitrate appears to be the most advantageous because it is conservative and because the difference between the concentrations in the two endmembers is large relative to their variance. The ??18O- based model was very sensitive to variability within the quick flow endmember, and SC was not conservative over the timescale of the storm response. We conclude that a nitrate-based two-endmember mixing model might provide a useful approach for quantifying the temporally variable quick flow component of spring flow in some karst systems. ?? 2008 National Ground Water Association.

  2. Hydrological controls on transient aquifer storage in a karst watershed

    Science.gov (United States)

    Spellman, P.; Martin, J.; Gulley, J. D.

    2017-12-01

    While surface storage of floodwaters is well-known to attenuate flood peaks, transient storage of floodwaters in aquifers is a less recognized mechanism of flood peak attenuation. The hydraulic gradient from aquifer to river controls the magnitude of transient aquifer storage and is ultimately a function of aquifer hydraulic conductivity, and effective porosity. Because bedrock and granular aquifers tend to have lower hydraulic conductivities and porosities, their ability to attenuate flood peaks is generally small. In karst aquifers, however, extensive cave systems create high hydraulic conductivities and porosities that create low antecedent hydraulic gradients between aquifers and rivers. Cave springs can reverse flow during high discharges in rivers, temporarily storing floodwaters in the aquifer thus reducing the magnitude of flood discharge downstream. To date however, very few studies have quantified the magnitude or controls of transient aquifer storage in karst watersheds. We therefore investigate controls on transient aquifer storage by using 10 years of river and groundwater data from the Suwannee River Basin, which flows over the karstic upper Floridan aquifer in north-central Florida. We use multiple linear regression to compare the effects of three hydrological controls on the magnitude of transient aquifer storage: antecedent stage, recharge and slope of hydrograph rise. We show the dominant control on transient aquifer storage is antecedent stage, whereby lower stages result in greater magnitudes of transient aquifer storage. Our results suggest that measures of groundwater levels prior to an event can be useful in determining whether transient aquifer storage will occur and may provide a useful metric for improving predictions of flood magnitudes.

  3. Combining hydraulic model, hydrogeomorphological observations and chemical analyses of surface waters to improve knowledge on karst flash floods genesis

    Directory of Open Access Journals (Sweden)

    F. Raynaud

    2015-06-01

    Full Text Available During a flood event over a karst watershed, the connections between surface and ground waters appear to be complex ones. The karst may attenuate surface floods by absorbing water or contribute to the surface flood by direct contribution of karst waters in the rivers (perennial and overflowing springs and by diffuse resurgence along the hillslopes. If it is possible to monitor each known outlet of a karst system, the diffuse contribution is yet difficult to assess. Furthermore, all these connections vary over time according to several factors such as the water content of the soil and underground, the rainfall characteristics, the runoff pathways. Therefore, the contribution of each compartment is generally difficult to assess, and flood dynamics are not fully understood. To face these misunderstandings and difficulties, we analysed surface waters during six recent flood events in the Lirou watershed (a karst tributary of the Lez, in South of France. Because of the specific chemical signature of karst waters, chemical analyses can supply information about water pathways and flood dynamics. Then, we used the dilution law to combine chemical results, flow data and field observations to assess the dynamics of the karst component of the flood. To end, we discussed the surface or karst origin of the waters responsible for the apparent runoff coefficient rise during flash karst flood.

  4. Forecasting Interest Rates and Inflation

    DEFF Research Database (Denmark)

    Chun, Albert Lee

    the best overall for short horizon forecasts of short to medium term yields and inflation. Econometric models with shrinkage perform the best over longer horizons and maturities. Aggregating over a larger set of analysts improves inflation surveys while generally degrading interest rates surveys. We...

  5. Bullita cave system, Judbarra / Gregory Karst, tropical Australia; Sistemas de cuevas de Bullita, Judbarra / Gregory Karst, Australia tropical

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, K. G.; Martini, J. E. J.

    2016-07-01

    In the monsoon tropics of northern Australia, Bullita Cave is the largest (123 km) of a group of extensive, horizontal, joint-controlled, dense network maze caves which are epikarst systems lying at shallow depth beneath a well-developed karrenfield. The Judbarra / Gregory Karst and its caves are restricted to the outcrop belt of the thin, sub-horizontal, Proterozoic Supplejack Dolostone. Karst is further restricted to those parts of the Supplejack that have escaped a secondary dolomitisation event. The karrenfield and underlying cave system are intimately related and have developed in step as the Supplejack surface was exposed by slope retreat. Both show a lateral zonation of development grading from youth to old age. Small cave passages originate under the recently exposed surface, and the older passages at the trailing edge become un roofed or destroyed as the, by then deeply-incised, karrenfield breaks up into isolated ruiniform blocks and pinnacles. Vertical development of the cave has been generally restricted to the epikarst zone by a 3m bed of impermeable and incompetent shale beneath the Supplejack which first perched the water-table, forming incipient phreatic passages above it, and later was eroded by vadose flow to form an extensive horizontal system of passages 10-20m below the karren surface. Some lower cave levels in underlying dolostone occur adjacent to recently incised surface gorges. Speleogenesis is also influenced by the rapid, diffuse, vertical inflow of storm water through the karrenfield, and by ponding of the still-aggressive water within the cave during the wet season dammed up by levees of sediment that accumulate beneath the degraded trailing edge of the karrenfield. The soil, and much biological activity, is not at the bare karren surface, but down on the cave floors, which aids epikarstic solution at depth rather than on the surface. (Author)

  6. A preliminary study on the feedback of heat transfer on groundwater flow in a Karst geothermal field

    Science.gov (United States)

    Kong, Y.; Pang, Z.; Hu, S.; Pang, J.; Shao, H.; Kolditz, O.

    2014-12-01

    In deep sedimentary basins, groundwater movement can significantly alter the heat flow pattern. At the same time, heat flux induced temperature change can reversely determine the flow regime through density dependent convection process. In Karst aquifers, the heterogeneity in the carbonate rocks makes the identification of this feedback much more complex. In this work, a preliminary study has been made on this feedback in Xiongxian geothermal field. The Karst aquifer in our site has an average thickness of about 1000 m, and is overlaid by over 400 m of quaternary clay, and subsequently 600 m of Neogene sandstone. Geothermal energy has been exploited in the site for space heating. During the heating period from Nov 15th to Mar 15th every year, hot water was extracted from the aquifer and re-injected after the heat extraction. A detailed temperature logging has been carried out in the field, both before and after the heating period, with the consideration that temperature distribution will be affected by the re-injection of cold water. The vertical distribution of temperature in the cap rock shows a constant positive gradient over depth. The heat flux at different locations has been calculated respectively. It is found to decline from southwest to northeast, with the highest value of 113.9 mW/m2 to the lowest of 80.6 mW/m2. This pattern can be well explained by the tectonic features. More interestingly, two inflection points appear on the temperature profile of the Karst layer, revealing strong influence from the cold re-injection water. Also, a 3℃ temperature difference was observed in the June and October measurement, which is related to the reservoir recovery. Currently, a 3D numerical model is being constructed, using the open-source software OpenGeoSys. Heat transport process is coupled with density dependent flow in a monolithic approach, to simulate both heat conduction and groundwater convection. This model will help to quantify the feedback from heat

  7. Differentiated spring behavior under changing hydrological conditions in an alpine karst aquifer

    Science.gov (United States)

    Filippini, Maria; Squarzoni, Gabriela; De Waele, Jo; Fiorucci, Adriano; Vigna, Bartolomeo; Grillo, Barbara; Riva, Alberto; Rossetti, Stefano; Zini, Luca; Casagrande, Giacomo; Stumpp, Christine; Gargini, Alessandro

    2018-01-01

    Limestone massifs with a high density of dolines form important karst aquifers in most of the Alps, often with groundwater circulating through deep karst conduits and water coming out of closely spaced springs with flow rates of over some cubic meters per second. Although several hydrogeological studies and tracing experiments were carried out in many of these carbonate mountains in the past, the hydrogeology of most of these karst aquifers is still poorly known. Geological, hydrodynamic and hydrochemical investigations have been carried out in one of the most representative of these areas (Cansiglio-Monte Cavallo, NE Italy) since spring 2015, in order to enhance the knowledge on this important type of aquifer system. Additionally, a cave-to-spring multitracer test was carried out in late spring 2016 by using three different fluorescent tracers. This hydrogeological study allowed: 1) gathering new detailed information on the geological and tectonic structure of such alpine karst plateau; 2) defining discharge rates of the three main springs (Gorgazzo, Santissima, and Molinetto) by constructing rating curves; 3) understanding the discharging behavior of the system with respect to different recharge conditions; 4) better defining the recharge areas of the three springs. The three nearby springs (the spring front stretches over 5 km), that drain the investigated karst aquifer system, show different behaviors with respect to changing discharge conditions, demonstrating this aquifer to be divided in partially independent drainage systems under low-flow conditions, when their chemistry is clearly differentiated. Under high-flow conditions, waters discharging at all springs show more similar geochemical characteristics. The combination of geochemistry, hydrodynamic monitoring and dye tracing tests has shown that the three springs have different recharge areas. The study points out that even closely spaced karst springs, that apparently drain the same karst mountain, can

  8. Ground Radiometric Method as a Tool for Determining the Surface Boundary of a Buried Bauxitic Karst

    Directory of Open Access Journals (Sweden)

    Kamal Kareem Ali

    2011-12-01

    Full Text Available Forty two ground radiometric measurements along nine traverses within a rectangular network area were taken across a bauxitic karst within the Ubaid Formation (Lower Jurassic in the Western Desert of Iraq. A 4-Channel Gamma Ray Spectrometer (GAD-6 with sodium iodide NaI (Tl crystal (GSP-4S was used in the field to measure the total radioactivity of the surface soil. Soil samples collected from the surface at each measurement point and core samples collected from a test well penetrating the karst were analyzed by Gamma ray spectrometer. The main objective of this study was to detect the hidden bauxitic karst and determine its surface boundary. The radioactivity on the surface of the karst was ranging between 60 and 80 count per second (c/s, while the background radioactivity of the Ubaid Formation, which hosts the karst, was ranging between 100 and150 c/s. Chemical weathering, especially dissolution and leaching moved uranium (238U and thorium(232Th from the overburden downward. Accordingly, these elements have been adsorbed on the surface of clay minerals and bauxite buried at a depth of about 5m causing enrichment with radioactivity. The leached overburden lack radioelements, so its radioactivity was less than background radioactivity level. The gamma ray spectroanalysis showed that the radioactivity of 238U and 232Th in the overburden was 0.5 and 3 Bq/Kg, whereas, in the bauxite and flint clay bed, it was 240 and 160 Bq/Kg respectively. Based on the radioactivity anomaly contrast on the surface, an isorad map was plotted and the karst diameter which represents low anomaly was determined to be ranging from 150 to 200m. The current study demonstrates that the ground radiometric method is quite useful for detecting the bauxitic karst and inferring its surface boundaries.

  9. Organic carbon storage in four ecosystem types in the karst region of southwestern China.

    Directory of Open Access Journals (Sweden)

    Yuguo Liu

    Full Text Available Karst ecosystems are important landscape types that cover about 12% of the world's land area. The role of karst ecosystems in the global carbon cycle remains unclear, due to the lack of an appropriate method for determining the thickness of the solum, a representative sampling of the soil and data of organic carbon stocks at the ecosystem level. The karst region in southwestern China is the largest in the world. In this study, we estimated biomass, soil quantity and ecosystem organic carbon stocks in four vegetation types typical of karst ecosystems in this region, shrub grasslands (SG, thorn shrubbery (TS, forest - shrub transition (FS and secondary forest (F. The results showed that the biomass of SG, TS, FS, and F is 0.52, 0.85, 5.9 and 19.2 kg m(-2, respectively and the corresponding organic cabon storage is 0.26, 0.40, 2.83 and 9.09 kg m(-2, respectively. Nevertheless, soil quantity and corresponding organic carbon storage are very small in karst habitats. The quantity of fine earth overlaying the physical weathering zone of the carbonate rock of SG, TS, FS and F is 38.10, 99.24, 29.57 and 61.89 kg m(-2, respectively, while the corresponding organic carbon storage is only 3.34, 4.10, 2.37, 5.25 kg m(-2, respectively. As a whole, ecosystem organic carbon storage of SG, TS, FS, and F is 3.81, 4.72, 5.68 and 15.1 kg m(-2, respectively. These are very low levels compared to other ecosystems in non-karst areas. With the restoration of degraded vegetation, karst ecosystems in southwestern China may play active roles in mitigating the increasing CO2 concentration in the atmosphere.

  10. Karst aquifer characterization using geophysical remote sensing of dynamic recharge events

    Science.gov (United States)

    Grapenthin, R.; Bilek, S. L.; Luhmann, A. J.

    2017-12-01

    Geophysical monitoring techniques, long used to make significant advances in a wide range of deeper Earth science disciplines, are now being employed to track surficial processes such as landslide, glacier, and river flow. Karst aquifers are another important hydrologic resource that can benefit from geophysical remote sensing, as this monitoring allows for safe, noninvasive karst conduit measurements. Conduit networks are typically poorly constrained, let alone the processes that occur within them. Geophysical monitoring can also provide a regionally integrated analysis to characterize subsurface architecture and to understand the dynamics of flow and recharge processes in karst aquifers. Geophysical signals are likely produced by several processes during recharge events in karst aquifers. For example, pressure pulses occur when water enters conduits that are full of water, and experiments suggest seismic signals result from this process. Furthermore, increasing water pressure in conduits during recharge events increases the load applied to conduit walls, which deforms the surrounding rock to yield measureable surface displacements. Measureable deformation should also occur with mass loading, with subsidence and rebound signals associated with increases and decreases of water mass stored in the aquifer, respectively. Additionally, geophysical signals will likely arise with turbulent flow and pore pressure change in the rock surrounding conduits. Here we present seismic data collected during a pilot study of controlled and natural recharge events in a karst aquifer system near Bear Spring, near Eyota, MN, USA as well as preliminary model results regarding the processes described above. In addition, we will discuss an upcoming field campaign where we will use seismometers, tiltmeters, and GPS instruments to monitor for recharge-induced responses in a FL, USA karst system with existing cave maps, coupling these geophysical observations with hydrologic and

  11. An examination of the factors governing the development of karst topography in the Cumberland Valley of Pennsylvania

    International Nuclear Information System (INIS)

    Ackerman, R.V.

    1993-01-01

    The landscape of the Cumberland Valley of South Central Pennsylvania is dominated by karst topography. A study was initiated to determine if the development of karst was controlled primarily by geologic structure or by lithologic differences. Existing data concerning the geographic locations of karst features, the hydrogeologic characteristics of the Cumberland Valley, and the chemistry of the eleven carbonate formations within the 518 km 2 study area were compiled. Data concerning 366 mapped sinkholes and over 9,000 additional karst features and their relations to the structural, lithological and spatial characteristics of the study area were collected and compiled into the database. Other factors contributing to karst development such as groundwater flow, soil and colluvium characteristics, and geographic distribution were considered. The data suggest that structure dominates lithology in the development of karst features within the study area. Structural features such as fractures, joints and folds, which create secondary porosity, are prerequisite for solution of the carbonate bedrock. Joint systems, fold axes, igneous intrusions, caves, springs and groundwater flow have a significant impact on the development of karst features. The presence of faults proved inconclusive. There are a greater number of karst features per unit area in areas of purer limestones (units with a lower percentage of acid insoluble residue). Lithological variations impact karst development only when structural features are present to provide secondary porosity that enhances chemical weathering. The distribution of karst features and the geologic factors governing their development and distribution should be taken into account when land-use decisions in karst terrains are made

  12. Authors of clinical trials reported individual and financial conflicts of interest more frequently than institutional and nonfinancial ones: a methodological survey.

    Science.gov (United States)

    Hakoum, Maram B; Jouni, Nahla; Abou-Jaoude, Eliane A; Hasbani, Divina Justina; Abou-Jaoude, Elias A; Lopes, Luciane Cruz; Khaldieh, Mariam; Hammoud, Mira Z; Al-Gibbawi, Mounir; Anouti, Sirine; Guyatt, Gordon; Akl, Elie A

    2017-07-01

    Conflicts of interest (COIs) are increasingly recognized as important to disclose and manage in health research. The objective of this study was to assess the reporting of both financial and nonfinancial COI by authors of randomized controlled trials published in a representative sample of clinical journals. We searched Ovid Medline and included a random sample of 200 randomized controlled trials published in 2015 in one of the 119 Core Clinical Journals. We classified COI using a comprehensive framework that includes the following: individual COIs (financial, professional, scholarly, advocatory, personal) and institutional COIs (financial, professional, scholarly, and advocatory). We conducted descriptive and regression analyses. Of the 200 randomized controlled trials, 188 (94%) reported authors' COI disclosures that were available in the main document (92%) and as International Committee of Medical Journal Editors forms accessible online (12%). Of the 188 trials, 57% had at least one author reporting at least one COI; in all these trials, at least one author reported financial COI. Institutional COIs (11%) and nonfinancial COIs (4%) were less commonly reported. References to COI disclosure statements for editors (1%) and medical writers (0%) were seldom present. Regression analyses showed positive associations between reporting individual financial COI and higher journal impact factor (odds ratio [OR] = 1.06, 95% confidence interval [CI] = 1.02-1.10), larger number of authors (OR = 1.10, 95% CI 1.02-1.20), affiliation with an institution from a high-income country (OR = 16.75, 95% CI 3.38-82.87), and trials reporting on pharmacological interventions (OR = 2.28, 95% CI 1.13-4.62). More than half of published randomized controlled trials report that at least one author has a COI. Trial authors report financial COIs more often than nonfinancial COIs and individual COIs more frequently than institutional COIs. Copyright © 2017 Elsevier Inc. All rights

  13. The Role of Attached and Free-Living Bacteria in Biodegradation in Karst Aquifers

    Directory of Open Access Journals (Sweden)

    Ahmad Kheder

    2011-12-01

    Full Text Available Natural attenuation of groundwater contamination occurs at some level for all aquifers impacted with organic contaminants. The issues regarding natural attenuation are whether it takes place at a sufficient rate to be protective of human health and the environment. Implementation of a Monitored Natural Attenuation (MNA remedial alternative for groundwater requires parties responsible for the contamination to demonstrate to regulators and the public that MNA is protective at a given site. Analysis of MNA for remediation of karst aquifers is hampered by a lack of understanding of biodegradation in karst environments. The lack of studies examining biodegradation in karst aquifers may in large part be due to the widespread perception that contaminants are rapidly flushed out of karst aquifers resulting in insufficient residence times for contaminants to biodegrade. In highly developed and well-connected conduit systems, the rate of contaminant migration is perceived to be much faster than the rate of biodegradation. This perception of contaminant transport is largely incorrect. Tracer studies for karst aquifers often indicate that these aquifers are characterized by diverse flow regimes and storage capabilities. Additionally, it is also believed that if bioremediation in bedrock aquifers is dependent upon contact between surface-attached bacteria and contaminants, then bioremediation would be limited by the low surface-area-to-volume ratio (SA/V of karst aquifers. A quantitative basis, however, for accepting or rejecting the assumption that attached bacteria dominate the biodegradation process in karst conduits has not been shown. The objective of this research was to determine if free-living karst bacteria from contributed as much to toluene biodegradation as attached bacteria. This is an important area of research. Research indicates bacteria are both attached and free-living in karst aquifers and it is unrealistic to think that only the attached

  14. Method of calculating pilestrip foundations in case of karst hole formation

    Directory of Open Access Journals (Sweden)

    Gotman Al'fred Leonidovich

    2014-02-01

    Full Text Available The paper presents pile strip foundations in the areas with karst risk. The analysis of karst hole formation mechanism shows the lateral soil pressure on the piles caused by the downfallen soil on the hole rims, which transfers around the hole edges during karst hole formation. In this case, the horizontal pressure of the pile reactive force in the area of the pile connection with the raft is transferred to the raft. Pile failure at the hole boundaries will lead to the increase of the raft bearing distance above the karst hole. The inadequate raft bearing capacity can provoke the emergency situation. The existing Codes on karst protective foundations design do not contain the analysis of pile and raft horizontal pressure under the downfallen soil.The goal of this work is to develop the method of pile strip foundations analysis in the areas with karst risk in case of karst hole formation. The analysis of stress-strain state of the system “foundation soil — pile foundation” was carried out using numerical modeling in geotechnical program MIDAS GTS. As a result of numerical investigations, the diagrams of lateral soil pressure onto the piles and the raft are plotted. The pile pressure is approximated with the linear or bilinear function in dependence on geometrical dimensions of the karst hole and strength characteristics of soil that generates the horizontal pressure.In the Codes, the analysis of a pile under lateral soil pressure is given for a pile with the free end. In the problem examined, the pile head has the hinged bearing in place of the connection with the raft. In view of the given boundary data, the pile design scheme is plotted. The inner forces and displacements of the pile are determined by integrating the differential equation of a pile bending. The consistent integrations are evaluated out of the boundary conditions. The boundary values of inner forces and displacements are evaluated from the equality conditions of

  15. Estimation of underground river water availability based on rainfall in the Maros karst region, South Sulawesi

    Science.gov (United States)

    Arsyad, Muhammad; Ihsan, Nasrul; Tiwow, Vistarani Arini

    2016-02-01

    Maros karst region, covering an area of 43.750 hectares, has water resources that determine the life around it. Water resources in Maros karst are in the rock layers or river underground in the cave. The data used in this study are primary and secondary data. Primary data includes characteristics of the medium. Secondary data is rainfall data from BMKG, water discharge data from the PSDA, South Sulawesi province in 1990-2010, and the other characteristics data Maros karst, namely cave, flora and fauna of the Bantimurung Bulusaraung National Park. Data analysis was conducted using laboratory test for medium characteristics Maros karst, rainfall and water discharge were analyzed using Minitab Program 1.5 to determine their profile. The average rainfall above 200 mm per year occurs in the range of 1999 to 2005. The availability of the water discharge at over 50 m3/s was happened in 1993 and 1995. Prediction was done by modeling Autoregressive Integrated Moving Average (ARIMA), with the rainfall data shows that the average precipitation for four years (2011-2014) will sharply fluctuate. The prediction of water discharge in Maros karst region was done for the period from January to August in 2011, including the type of 0. In 2012, the addition of the water discharge started up in early 2014.

  16. Karst geomorphology and hydrology of the Shenandoah Valley near Harrisonburg, Virginia

    Science.gov (United States)

    Doctor, Daniel H.; Orndorff, Wil; Maynard, Joel; Heller, Matthew J.; Casile, Gerolamo C.

    2014-01-01

    The karst of the central Shenandoah Valley has characteristics of both shallow and deep phreatic formation. This field guide focuses on the region around Harrisonburg, Virginia, where a number of these karst features and their associated geologic context can be examined. Ancient, widespread alluvial deposits cover much of the carbonate bedrock on the western side of the valley, where shallow karstification has resulted in classical fluviokarst development. However, in upland exposures of carbonate rock, isolated caves exist atop hills not affected by surface processes other than exposure during denudation. The upland caves contain phreatic deposits of calcite and fine-grained sediments. They lack any evidence of having been invaded by surface streams. Recent geologic mapping and LIDAR (light detection and ranging) elevation data have enabled interpretive association between bedrock structure, igneous intrusions, silicification and brecciation of host carbonate bedrock, and the location of several caves and karst springs. Geochemistry, water quality, and water temperature data support the broad categorization of springs into those affected primarily by shallow near-surface recharge, and those sourced deeper in the karst aquifer. The deep-seated karst formation occurred in the distant past where subvertical fracture and fault zones intersect thrust faults and/or cross-strike faults, enabling upwelling of deep-circulating meteoric groundwater. Most caves formed in such settings have been overprinted by later circulation of shallow groundwater, thus removing evidence of the history of earliest inception; however, several caves do preserve evidence of an earlier formation.

  17. Relationship among land surface temperature and LUCC, NDVI in typical karst area.

    Science.gov (United States)

    Deng, Yuanhong; Wang, Shijie; Bai, Xiaoyong; Tian, Yichao; Wu, Luhua; Xiao, Jianyong; Chen, Fei; Qian, Qinghuan

    2018-01-12

    Land surface temperature (LST) can reflect the land surface water-heat exchange process comprehensively, which is considerably significant to the study of environmental change. However, research about LST in karst mountain areas with complex topography is scarce. Therefore, we retrieved the LST in a karst mountain area from Landsat 8 data and explored its relationships with LUCC and NDVI. The results showed that LST of the study area was noticeably affected by altitude and underlying surface type. In summer, abnormal high-temperature zones were observed in the study area, perhaps due to karst rocky desertification. LSTs among different land use types significantly differed with the highest in construction land and the lowest in woodland. The spatial distributions of NDVI and LST exhibited opposite patterns. Under the spatial combination of different land use types, the LST-NDVI feature space showed an obtuse-angled triangle shape and showed a negative linear correlation after removing water body data. In summary, the LST can be retrieved well by the atmospheric correction model from Landsat 8 data. Moreover, the LST of the karst mountain area is controlled by altitude, underlying surface type and aspect. This study provides a reference for land use planning, ecological environment restoration in karst areas.

  18. Peculiarity and vulnerability of karst settings, analyzed through a review of available environmental indices

    Science.gov (United States)

    Parise, Mario; Mazzei, Marianna

    2016-04-01

    Karst is a unique environment on Earth, characterized by a variety of peculiar geological and hydrological features, that are expressed by typical landforms at the surface (doline, ponor, polje, etc.) and underground (single cave, sinkhole, complex hypogean systems consisting of sequences of pits and galleries, etc.). Among the main characters of karst, the direct connection between the surface and the underground is at the origin of the fragility of karst settings, and the related high vulnerability. Many different types of natural geological hazards (or geo-hazards) may potentially affect karst lands, with sinkholes and flash floods being the most frequent and typical. In addition, karst is exposed to a variety of anthropogenic disturbances as well, including loss of natural landscapes, destruction of caves and speleothems, and contamination and pollution problems. At this latter regard, it has to be reminded that karst aquifers host high quality groundwaters, that are used as source of drinking water worldwide, with estimates indicating that the supply of drinking water from karst is going to have a significant increase in the next decades, From all of this, the importance in fully defining the karst setting, and in a detail examination of all the natural and anthropogenic events that may cause negative effects on it, comes out. Uniqueness of karst has been acknowledged since a long time, but only in recent years efforts have been made to develop approaches and methods specifically dedicated to this peculiar environment. Such approaches represent definitely a mandatory step in the correct management of karst terranes, providing useful elements to stakeholders, land managers and people living in karst lands about their fragility, and the need to safeguard them and the natural resources therein contained. Starting from these considerations, in this contribution we review the main environmental indices dedicated to karst that have been recently proposed in the

  19. Imaging of underground karst water channels using an improved multichannel transient Rayleigh wave detecting method.

    Science.gov (United States)

    Zheng, Xuhui; Liu, Lei; Sun, Jinzhong; Li, Gao; Zhou, Fubiao; Xu, Jiemin

    2018-01-01

    Geological and hydrogeological conditions in karst areas are complicated from the viewpoint of engineering. The construction of underground structures in these areas is often disturbed by the gushing of karst water, which may delay the construction schedule, result in economic losses, and even cause heavy casualties. In this paper, an innovative method of multichannel transient Rayleigh wave detecting is proposed by introducing the concept of arrival time difference phase between channels (TDP). Overcoming the restriction of the space-sampling law, the proposed method can extract the phase velocities of different frequency components from only two channels of transient Rayleigh wave recorded on two adjacent detecting points. This feature greatly improves the work efficiency and lateral resolution of transient Rayleigh wave detecting. The improved multichannel transient Rayleigh wave detecting method is applied to the detection of karst caves and fractures in rock mass of the foundation pit of Yan'an Road Station of Guiyang Metro. The imaging of the detecting results clearly reveals the distribution of karst water inflow channels, which provided significant guidance for water plugging and enabled good control over karst water gushing in the foundation pit.

  20. Evaluation of subsidence hazard in mantled karst setting: a case study from Val d'Orléans (France)

    Science.gov (United States)

    Perrin, Jérôme; Cartannaz, Charles; Noury, Gildas; Vanoudheusden, Emilie

    2015-04-01

    Soil subsidence/collapse is a major geohazard occurring in karst region. It occurs as suffosion or dropout sinkholes developing in the soft cover. Less frequently it corresponds to a breakdown of karst void ceiling (i.e., collapse sinkhole). This hazard can cause significant engineering challenges. Therefore decision-makers require the elaboration of methodologies for reliable predictions of such hazards (e.g., karst subsidence susceptibility and hazards maps, early-warning monitoring systems). A methodological framework was developed to evaluate relevant conditioning factors favouring subsidence (Perrin et al. submitted) and then to combine these factors to produce karst subsidence susceptibility maps. This approach was applied to a mantled karst area south of Paris (Val d'Orléans). Results show the significant roles of the overburden lithology (presence/absence of low-permeability layer) and of the karst aquifer piezometric surface position within the overburden. In parallel, an experimental site has been setup to improve the understanding of key processes leading to subsidence/collapse and includes piezometers for measurements of water levels and physico-chemical parameters in both the alluvial and karst aquifers as well as surface deformation monitoring. Results should help in designing monitoring systems to anticipate occurrence of subsidence/collapse. Perrin J., Cartannaz C., Noury G., Vanoudheusden E. 2015. A multicriteria approach to karst subsidence hazard mapping supported by Weights-of-Evidence analysis. Submitted to Engineering Geology.

  1. Comprehensive surface geophysical investigation of karst caves ahead of the tunnel face: A case study in the Xiaoheyan section of the water supply project from Songhua River, Jilin, China

    Science.gov (United States)

    Bin, Liu; Zhengyu, Liu; Shucai, Li; Lichao, Nie; Maoxin, Su; Huaifeng, Sun; Kerui, Fan; Xinxin, Zhang; Yonghao, Pang

    2017-09-01

    This paper describes the application of a comprehensive surface geophysical investigation of underground karst systems ahead of the tunnel face in the Xiaoheyan section in the main line of the water supply project from Songhua River, located in Jilin, China. To make an accurate investigation, Surface Electrical Resistivity Tomography (S-ERT), Transient Electromagnetic Method (TEM), Geological Drilling (Geo-D) and Three-dimensional Cross-hole Electrical Resistivity Tomography (3D cross-hole ERT) were applied to gain a comprehensive interpretation. To begin with, S-ERT and TEM are adopted to detect and delineate the underground karst zone. Based on the detection results, surface and in-tunnel Geo-D are placed in major areas with more specific and accurate information gained. After that, survey lines of 3D cross-hole ERT are used to conduct detailed exploration towards underground karst system. In the comprehensive investigation, it is the major question to make the best of prior information so as to promote the quality of detection. The paper has put forward strategies to make the full use of effective information in data processing and the main ideas of those strategies include: (1) Take the resistivity distribution of the subsurface stratum gained by S-ERT inversion as the initial model of TEM inversion; (2) Arrange borehole positions with the results of S-ERT and TEM. After that, gain more accurate information about resistivity of subsurface stratum using those boreholes located; (3) Through the comprehensive analysis of the information about S-ERT, TEM and Geo-D, set the initial model of 3D cross-hole resistivity inversion and meanwhile, gain the variation range of stratum resistivity. At last, a 3D cross-hole resistivity inversion based on the incorporated initial model and inequality constraint is conducted. Constrained inversion and joint interpretation are realized by the effective use of prior information in comprehensive investigation, helping to suppress

  2. The impact of human activities on dolines (sinkholes: Typical geomorphologic features on Karst (Slovenia and possibilities of their preservation

    Directory of Open Access Journals (Sweden)

    Cernatič-Gregorič Anica

    2010-01-01

    Full Text Available This paper focuses on dolines, one of the main geomorphologic features on Karst (Slovenia. Dolines are a dominant surface feature and also a main source of fertile soil on Karst. Consequently they represent a significant element of the Karst landscape and an important part of traditional agricultural land use. Negative impacts due to rapid economic development in the last decade are affecting Karst seriously, mostly by degradation of typical landscape features. The main purpose of our work was to document the current extent of damage caused on dolines and consequently on Karst landscape. The paper discusses the gravity of the problem and points out the insufficiency of current legislation concerning landscape protection. Based on the research results the paper comments on possible consequences if the degradation process continues. .

  3. Discussion on karst tunnel water inrush and prevention%谈岩溶隧道突水与防治

    Institute of Scientific and Technical Information of China (English)

    张高青

    2016-01-01

    简要概括了岩溶的定义,从地质、气象、施工三方面,分析了影响岩溶隧道突水的主要因素,论述了岩溶隧道突水造成的危害,提出了岩溶隧道突水的预防与治理措施,为岩溶隧道突水防治提供理论依据。%This paper briefly generalized the definition of karst,from the geology,meteorology,construction three aspects,analyzed the main fac-tors influence of karst tunnel water inrush,discussed the disasters caused by karst tunnel water inrush,put forward the prevention and treatment measures of karst tunnel water inrush,provided theoretical basis for prevention and control of karst tunnel water inrush.

  4. Water control at certain karst U-mining area

    International Nuclear Information System (INIS)

    Lei Mingxin; Xu Qiang

    2010-01-01

    To ensure mining security, water control for certain mining area is designed. Hydrogeological conditions in the studied area are analyzed. Four methods were used to calculate the inflow of water at mineral area, such as 'bigwell' method and 'groundwater isostatic' method according to the karst development. The calculated data for average inflow of water for the 100 m middle section are mainly compared with the data for the inflow of spring water in this deposit observed during the last five years. The difference between them is found minor. This indicates that the parameters selected for the calculation of inflow of water are reasonable and the methods used are suitable. Taking into account the above, it is decided to use the combination of surface water control and groundwater control Surface water control first,and groundwater control second, Five methods are used for surface water control such as plugging, filling, stopping, draining and dredging. Three methods for groundwater control such as curtain grouting, drainage in advance and blocking. The implimentation of this program will greatly reduce the threat of groundwater in ming area to mining operation and the cost of treatment of water discharge in mining pits and wells ,and effectively protect the environment and ensure the local people's living and production. (authors)

  5. Karst development and speleogenesis, Isla de Mona, Puerto Rico

    Science.gov (United States)

    Frank, E.F.; Mylroie, J.; Troester, J.; Alexander, E.C.; Carew, J.L.

    1998-01-01

    Isla de Mona consists of a raised table-top Miocene-Pliocene reef platform bounded on three sides by vertical cliffs, up to 80 m high. Hundreds of caves ring the periphery of the island and are preferentially developed in, but not limited to, the Lirio Limestone/Isla de Mona Dolomite contact. These flank margin caves originally formed at sea level and are now exposed at various levels by tectonic uplift of the island (Franbk 1983; Mylroie et al. 1995b). Wall cusps, a characteristic feature of flank margin caves, are ubiquitois features. Comparisons among similar caves formed in the Bahamas and Isla de Mona reveal the same overall morphology throughout the entire range of sizes and complexities. The coincidence of the primary cave development zone with the Lirio Limestone/Isla de Mona Dolomite contact may result from syngenetic speleogenesis and dolomitization rather than preferential dissolution along a lithologic boundary. Tectonic uplift and glacioeustatic sea level fluctuations produced caves at a variety of elevations. Speleothem dissolution took place in many caves under phreatic conditions, evidence these caves were flooded after an initial period of subaerial exposure and speleothem growth. Several features around the perimeter of the island are interpreted to be caves whose roofs were removed by surficial denudation processes. Several large closed depressions and dense pit cave fields are further evidence of surficial karst features. The cliff retreat around the island perimeter since the speleogenesis of the major cave systems is small based upon the distribution of the remnant cave sections.

  6. Hydrogeology of Pico Frentes Karst system (Iberian range, Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Rosas, P.; Sanz, E.; Menendez-Pidal, I.

    2016-07-01

    The karst system of Pico Frentes has developed within an Upper Cretaceous calcareous series whose welldefined folded geometry determines that its aquifer reserves are held mainly in three hydraulically-connected synclines, with a groundwater capacity of between 5 and 7 hm3 . The recharge to this unconfined peneplain aquifer is autogenous and diffuse. On a large scale, groundwater flow is directed by the base of the synclines, while on a small scale, it flows along groundwater conduits towards the Fuentetoba Spring (210 l/s) and source of the River Mazos (50 l/s), following a highly variable flow regime of low inertia, with other smaller discharges emanating during periods of high water. Analysis of hydrographs of these springs indicates a very variable rate system and little power regulating natural, characteristic of a typical karstic aquifer, with great capacity for renewal and low residence time. Using hydrogram simulations of these upwellings using a mathematical rainfall-runoff model, a detailed quantification of the average water balance was made for a twenty-year time series. This water balance consists of 16,86 hm3 rainfall (100%); natural recharge, 8,35 hm3 (49,53%); EVT 8,50 hm3 (50,41%); pumped groundwater abstractions, 0,01hm3 (0,06%); surface runoff, 0 hm3, groundwater transfers to other aquifer, 0 hm3. (Author)

  7. Hydraulics of epiphreatic flow of a karst aquifer

    Science.gov (United States)

    Gabrovšek, Franci; Peric, Borut; Kaufmann, Georg

    2018-05-01

    The nature of epiphreatic flow remains an important research challenge in karst hydrology. This study focuses on the flood propagation along the epiphreatic system of Reka-Timavo system (Kras/Carso Plateau, Slovenia/Italy). It is based on long-term monitoring of basic physical parameters (pressure/level, temperature, specific electric conductivity) of ground water in six active caves belonging to the flow system. The system vigorously responds to flood events, with stage rising >100 m in some of the caves. Besides presenting the response of the system to flood events of different scales, the work focuses on the interpretation of recorded hydrographs in view of the known distribution and size of conduits and basic hydraulic relations. Furthermore, the hydrographs were used to infer the unknown geometry between the observation points. This way, the main flow restrictors, overflow passages and large epiphreatic storages were identified. The assumptions were tested with a hydraulic model, where the inversion procedure was used for an additional parameter optimisation. Time series of temperature and specific electric conductivity were used to assess the apparent velocities of flow between consecutive points.

  8. Quantitative Analysis of Karst Conduit Structure Parameters and Hydraulic Parameters Based on Tracer Test

    Science.gov (United States)

    Qiang, Z.; Zhiqiang, Z.; Xu, M.; Jinyu, S.; Jihong, Q.

    2017-12-01

    The Old Town of Lijiang is famous as the world cultural heritage since 1997, while characterized by its ancient buildings and natural scenery, water is the soul of the town. Around Heilongtan Springs, there are a large quantity of springs at the Old Town of Lijiang , which is an important part of the World Cultural Heritage. Heilongtan Springs is 2420m above the sea level, the annual variation of the flow rate varies greatly (0 8042 x 104 m3 / year). Recharge area Jiuzihai depressions is 6km long, 3km wide and 2800m above sea level, as main karst water recharge area karst funnel and the sink hole are developing on this planation surface, in the research area medium to thick layers of limestone made up Beiya formation (T2b) of Triassic system distributed widely, karst is strongly developed and the fissure caves water occurrence. In order to exploring the application of tracer test in karst hydrogeology, a tracer test was conducted from Jiuzihai depressions to Ganze Spring. Based on the hydrogeological conditions in the study area, tracer test was used for analysis of groundwater connectivity and flow field characteristics, quantitative analysis of Tracer Breakthrough Curves (BTC) with code Qtracer2. The results demonstated that there are hydraulic connection between Jiuzihai depressions with Ganze Spring, and there are other karst conduits in this area. The longitudinal dispersivity coefficient is 0.24 m2/s, longitudinal dispersivity is 12.06m, flow-channel volume is 3.08×104 m3, flow-channel surface area is 3.27×107m2, mean diameter is 1.42m, Reynolds number is 25187, Froude number is 0.0061, respectively. The groundwater in this area is in a slow turbulent state. The results are of great significance to understand the law of groundwater migration, establish groundwater quality prediction model and exploit karst water resources effectively.

  9. Interrelations between the surface waters of Danube, karst waters and thermal springs of Bad Deutsch Altenburg

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, P [Bundesversuchs- und Forschungsanstalt Arsenal, Vienna (Austria)

    1987-11-15

    Full text: As part of the preliminary works for the hydropower project Hainburg on the Danube, comprehensive geological, geophysical, hydrogeological, hydrological, hydrochemical and radiohydrometrical investigations were carried out. Special attention was paid to the area of Bad Deutsch Altenburg since questions of connections between Danube water, groundwater and the sulphur-medicinal springs of Bad Deutsch Altenburg and karst waters had to be settled. Long term observations and the data from series of analysed water samples led to the following conclusions: (1) The thermal deep groundwater, the autochthonous karst water, the shallow groundwater and the Danube belong to a common system with hydraulic interactions. (2) The discharge of the thermal mineral waters in Bad Deutsch Altenburg is caused by a NW-SE striking fault zone. (3) The thermal mineral waters are overburdened by the karst waters in the area Kirchenberg and Pfaffenberg. At the contact zone mixing occurs. Owing to changing pressure conditions and to the locally different conductivity of the karst aquifer the discharges of mineral waters differ in concentration and temperature. (4) The water level of the thermal mineral waterbody is 1 to 2 m above the water level of the Danube at low flow. This difference is equalized at the Danube water level above 141.5 m a.s.l. Above the mark 142 m a.s.l. a direct influence of the observation wells situated in the Park was observed. (5) Because the Danube has eroded the karst massif (Mesozoic limestones and dolomites, Leitha limestone) down to a depth of about 132-133 m a.s.l. the level of karst water drainage was deeper than today. Currently the area is covered by highly permeable gravels. (6) It is therefore assumed that a considerable amount of thermal water drains directly into the Danube. Recharge and mixing with the shallow groundwater was proved. (7) The considerable discharge implies a catchment which extends beyond the immediate environment. (author)

  10. Drowned reefs and antecedent karst topography, Au'au channel, S.E. Hawaiian Islands

    Science.gov (United States)

    Grigg, R.W.; Grossman, E.E.; Earle, S.A.; Gittings, S.R.; Lott, D.; McDonough, J.

    2002-01-01

    During the last glacial maximum (LGM), about 21,000 years ago, the Hawaiian Islands of Maui, Lanai, and Molokai were interconnected by limestone bridges, creating a super-island known as Maui-Nui. Approximately 120 m of sea-level rise during the Holocene Transgression flooded, and then drowned, these bridges separating the islands by inter-island channels. A new multibeam high-resolution bathymetric survey of the channels between the islands, coupled with observations and video-transects utilizing DeepWorker-2000 submersibles, has revealed the existence of numerous drowned reef features including concentric solution basins, solution ridges (rims), sand and sediment plains, and conical-shaped reef pinnacles. The concentric basins contain flat lagoon-like bottoms that are rimmed by steep-sided limestone walls. Undercut notches rim the basins at several depths, marking either sea-level still stands or paleo-lake levels. All of the solution basins shallower than 120 m were subaerial at the LGM, and at one stage or another may have been shallow shoreline lakes. Today, about 70 drowned reef pinnacles are scattered across the Maui-Lanai underwater bridge and all are situated in wave-sheltered positions. Most drowned during the interval between 14,000 and 10,000 years ago when sea-level rise averaged 15 mm/year. Virtually all of the surficial topography in the Au'au Channel today is a product of karst processes accentuated by marginal reef growth during the Holocene. Both the submerged basins and the drowned reefs represent an archive of sea-level and climate history in Hawaii during the late Quaternary.

  11. Responses of soil physical and chemical properties to karst rocky desertification evolution in typical karst valley area

    Science.gov (United States)

    Chen, Fei; Zhou, Dequan; Bai, Xiaoyong; zeng, Cheng; Xiao, Jianyong; Qian, Qinghuan; Luo, Guangjie

    2018-01-01

    In order to reveal the differences of soil physical and chemical properties and their response mechanism to the evolution of KRD. The characteristics of soil physical and chemical properties of different grades of KRD were studied by field sampling method to research different types of KRD in the typical karst valley of southern China. Instead of using space of time, to explore the response and the mechanisms of the soil physical and chemical properties at the different evolution process. The results showed that: (1) There were significant differences in organic matter, pH, total nitrogen, total phosphorus, total potassium, sediment concentration, clay content and AWHC in different levels of KRD environment. However, these indicators are not with increasing desertification degree has been degraded, but improved after a first degradation trends; (2) The correlation analysis showed that soil organic matter, acid, alkali, total nitrogen, total phosphorus, total potassium and clay contents were significantly correlated with other physical and chemical factors. They are the key factors of soil physical and chemical properties, play a key role in improving soil physical and chemical properties and promoting nutrient cycling; (3) The principal component analysis showed that the cumulative contribution rate of organic matter, pH, total nitrogen, total phosphorus, total potassium and sediment concentration was 80.26%, which was the key index to evaluate rocky desertification degree based on soil physical and chemical properties. The results have important theoretical and practical significance for the protection and restoration of rocky desertification ecosystem in southwest China.

  12. An internet survey of the characteristics and physical activity of community-dwelling Australian adults with acquired brain injury: Exploring interest in an internet-delivered self-management program focused on physical activity.

    Science.gov (United States)

    Jones, Taryn M; Dean, Catherine M; Dear, Blake F; Hush, Julia M; Titov, Nickolai

    2016-01-01

    Individuals with acquired brain injury (ABI) are more likely to be physically inactive and experience barriers to accessing services to address inactivity. This study was designed to guide the development of an internet-delivered self-management program to increase physical activity after ABI. The aims of this study were to examine the current physical activity status of community-dwelling Australian adults with ABI, the barriers to physical activity they experience and to explore interest an internet-delivered self-management program aimed at increasing physical activity. An online survey of Australian adults with ABI was used to collect information about demographic characteristics; general health; emotional well-being; mobility and physical activity status, and satisfaction; barriers to physical activity; confidence in overcoming barriers, and; interest in an internet self-management program. Data were analyzed descriptively and correlational analyses examined relationships between variables. Data were analyzed from 59 respondents. Over half were not satisfied with their current physical activity status. The most frequently reported barriers were pain/discomfort, fatigue and fear, and confidence to overcome these barriers was very low. Interest in an internet-delivered self-management program was high (74%) and not related to the amount of physical activity, satisfaction with physical activity and mobility status or total number of barriers. Australian adults with ABI are not satisfied with their activity levels and experience barriers in maintaining their physical activity levels. Participants were interested in accessing an internet-delivered self-management program aimed at improving physical activity levels. Therefore such a program warrants development and evaluation. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Hydrochemical constraints between the karst Tabular Middle Atlas Causses and the Saïs basin (Morocco): implications of groundwater circulation

    Science.gov (United States)

    Miche, Hélène; Saracco, Ginette; Mayer, Adriano; Qarqori, Khaoula; Rouai, Mohamed; Dekayir, Abdelilah; Chalikakis, Konstantinos; Emblanch, Christophe

    2018-02-01

    The karst Tabular Middle Atlas Causses reservoir is the main drinking-water supply of Fez-Meknes region (Saïs Basin) in Morocco. Recent analyses showed a decline in associated groundwater chemical quality and increased turbidity. To understand this hydrosystem, four surveys were undertaken during fall and spring, 2009-2011. Hydrogeochemical studies coupled with isotopic analyses (δ18O, δD and 222Rn) showed that the aquifers between the causses (mountains) and the Saïs Basin are of Liassic origin and at the southern extremities are of Triassic origin. Five recharge zones of different altitudes have been defined, including two main mixing zones in the south. Deuterium excess results suggest local recharge, while a plot of δ18O versus δD characterizes a confined aquifer in the eastern sector. 222Rn results reveal areas of rapid exchanges with an upwelling time of less than 2 weeks. A schematic conceptual model is presented to explain the groundwater circulation system and the behavior of this karst system.

  14. Stormwater infiltration and the 'urban karst' - A review

    Science.gov (United States)

    Bonneau, Jeremie; Fletcher, Tim D.; Costelloe, Justin F.; Burns, Matthew J.

    2017-09-01

    The covering of native soils with impervious surfaces (e.g. roofs, roads, and pavement) prevents infiltration of rainfall into the ground, resulting in increased surface runoff and decreased groundwater recharge. When this excess water is managed using stormwater drainage systems, flow and water quality regimes of urban streams are severely altered, leading to the degradation of their ecosystems. Urban streams restoration requires alternative approaches towards stormwater management, which aim to restore the flow regime towards pre-development conditions. The practice of stormwater infiltration-achieved using a range of stormwater source-control measures (SCMs)-is central to restoring baseflow. Despite this, little is known about what happens to the infiltrated water. Current knowledge about the impact of stormwater infiltration on flow regimes was reviewed. Infiltration systems were found to be efficient at attenuating high-flow hydrology (reducing peak magnitudes and frequencies) at a range of scales (parcel, streetscape, catchment). Several modelling studies predict a positive impact of stormwater infiltration on baseflow, and empirical evidence is emerging, but the fate of infiltrated stormwater remains unclear. It is not known how infiltrated water travels along the subsurface pathways that characterise the urban environment, in particular the 'urban karst', which results from networks of human-made subsurface pathways, e.g. stormwater and sanitary sewer pipes and associated high permeability trenches. Seepage of groundwater into and around such pipes is possible, meaning some infiltrated stormwater could travel along artificial pathways. The catchment-scale ability of infiltration systems to restore groundwater recharge and baseflow is thus ambiguous. Further understanding of the fate of infiltrated stormwater is required to ensure infiltration systems deliver optimal outcomes for waterway flow regimes.

  15. Investigation of karst collapse based on 3-D seismic technique and DDA method at Xieqiao coal mine, China

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Jian-Ping; Chen, Zhong-Hui [State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing 100083 (China); Institute of Rock Mechanical and Fractals, China University of Mining and Technology, Beijing 100083 (China); Peng, Su-Ping; Li, Yong-Jun [State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing 100083 (China); Xie, He-Ping [Institute of Rock Mechanical and Fractals, China University of Mining and Technology, Beijing 100083 (China)

    2009-06-01

    Karst collapse is a serious geological problem in most of the coal mines in the north of China, but recently it has been found in the south as well. The present study is aimed at investigating subsidence mechanism and deformation field of a karst collapse column at Xieqiao, in the south of China. A method of three-dimensional (3-D) seismic technique has been successful in exploring the spatial morphology of the karst collapse at Xieqiao, and the discontinuous deformation analysis (DDA) method is used to calculate the deformation field and analyze the subsidence mechanism. The results indicated that DDA could approximately simulate and back analyze the subsidence process and strata deformation fields. The subsidence processes of the collapse column depend on the sizes of the karst caves. With the continuous expansion of the karst caves, a semi-elliptic stress field, local separation strata and fracture zone will be formed around the karst cave. Moreover, they will gradually expand upwards along the vertical direction. The paper also indicates that the subsidence failure stage may trigger a sudden collapse of the karst column because of the sudden energy release. Also, it will make a great impact on the vicinity working face so as to cause a rock burst. The effects of the friction angle of rock strata on the subsidence mechanism were reported firstly based on DDA. (author)

  16. The development of deep karst in the anticlinal aquifer structure based on the coupling of multistage flow systems

    Science.gov (United States)

    Xu, M.; Zhong, L.; Yang, Y.

    2017-12-01

    Under the background of neotectonics, the multistage underground flow system has been form due the different responses of main stream and tributaries to crust uplift. The coupling of multistage underground flow systems influences the development of karst thoroughly. At first, the research area is divided into vadose area, shunted area and exorheic area based on the development characteristics of transverse valley. Combining the controlling-drain action with topographic index and analyzing the coupling features of multistage underground flow system. And then, based on the coupling of multistage underground flow systems, the characteristics of deep karst development were verified by the lossing degree of surface water, water bursting and karst development characteristics of tunnels. The vadose area is regional water system based, whose deep karst developed well. It resulted the large water inflow of tunnels and the surface water drying up. The shunted area, except the region near the transverse valleys, is characterized by regional water system. The developed deep karst make the surface water connect with deep ground water well, Which caused the relatively large water flow of tunnels and the serious leakage of surface water. The deep karst relatively developed poor in the regions near transverse valleys which is characterized by local water system. The exorheic area is local water system based, whose the deep karst developed poor, as well as the connection among surface water and deep ground water. It has result in the poor lossing of the surface water under the tunnel construction. This study broadens the application field of groundwater flow systems theory, providing a new perspective for the study of Karst development theory. Meanwhile it provides theoretical guidance for hazard assessment and environmental negative effect in deep-buried Karst tunnel construction.

  17. Assessment of key transport parameters in a karst system under different dynamic conditions based on tracer experiments: the Jeita karst system, Lebanon

    Science.gov (United States)

    Doummar, Joanna; Margane, Armin; Geyer, Tobias; Sauter, Martin

    2018-03-01

    Artificial tracer experiments were conducted in the mature karst system of Jeita (Lebanon) under various flow conditions using surface and subsurface tracer injection points, to determine the variation of transport parameters (attenuation of peak concentration, velocity, transit times, dispersivity, and proportion of immobile and mobile regions) along fast and slow flow pathways. Tracer breakthrough curves (TBCs) observed at the karst spring were interpreted using a two-region nonequilibrium approach (2RNEM) to account for the skewness in the TBCs' long tailings. The conduit test results revealed a discharge threshold in the system dynamics, beyond which the transport parameters vary significantly. The polynomial relationship between transport velocity and discharge can be related to the variation of the conduit's cross-sectional area. Longitudinal dispersivity in the conduit system is not a constant value (α = 7-10 m) and decreases linearly with increasing flow rate because of dilution effects. Additionally, the proportion of immobile regions (arising from conduit irregularities) increases with decreasing water level in the conduit system. From tracer tests with injection at the surface, longitudinal dispersivity values are found to be large (8-27 m). The tailing observed in some TBCs is generated in the unsaturated zone before the tracer actually arrives at the major subsurface conduit draining the system. This work allows the estimation and prediction of the key transport parameters in karst aquifers. It shows that these parameters vary with time and flow dynamics, and they reflect the geometry of the flow pathway and the origin of infiltrating (potentially contaminated) recharge.

  18. Disentangling the determinants of interest and willingness-to-pay for breast cancer susceptibility testing in the general population: a cross-sectional Web-based survey among women of Québec (Canada)

    Science.gov (United States)

    Blouin-Bougie, Jolyane; Amara, Nabil; Bouchard, Karine; Simard, Jacques; Dorval, Michel

    2018-01-01

    Objectives To identify common and specific individual factors that favour or impede women’s interest in and willingness-to-pay (WTP) for breast cancer susceptibility testing (BCST) and to identify the most impactful factors on both outcome measures. Design and methods This study used a self-administered cross-sectional Web-based questionnaire that included hypothetical scenarios about the availability of a new genetic test for breast cancer. Participants French-speaking women of the general population of Québec (Canada), aged between 35 and 69 years, were identified from a Web-based panel (2410 met the selection criteria, 1160 were reached and 1031 completed the survey). Measures The outcomes are the level of interest in and the range of WTP for BCST. Three categories of individual factors identified in the literature were used as potential explanatory factors, that is, demographic, clinical and psychosocial. Results Descriptive statistics indicated that the vast majority of sampled women are interested in BCST (90%). Among those, more than half of them are willing-to-pay for such a test (57%). The regression models pointed out several factors associated with both outcomes (eg, age, income, family history, locus of control-powerful others) and marginal effects were used to highlight the most impactful factors for each outcome. Conclusion The results of this study provide a proxy of the readiness of women of the general population to use and to pay for BCST. They also offer insights for developing inclusive and specific strategies to foster informed decision-making and guide the services offered by health organisations corresponding to women’s preferences and needs. PMID:29487071

  19. Disentangling the determinants of interest and willingness-to-pay for breast cancer susceptibility testing in the general population: a cross-sectional Web-based survey among women of Québec (Canada).

    Science.gov (United States)

    Blouin-Bougie, Jolyane; Amara, Nabil; Bouchard, Karine; Simard, Jacques; Dorval, Michel

    2018-02-27

    To identify common and specific individual factors that favour or impede women's interest in and willingness-to-pay (WTP) for breast cancer susceptibility testing (BCST) and to identify the most impactful factors on both outcome measures. This study used a self-administered cross-sectional Web-based questionnaire that included hypothetical scenarios about the availability of a new genetic test for breast cancer. French-speaking women of the general population of Québec (Canada), aged between 35 and 69 years, were identified from a Web-based panel (2410 met the selection criteria, 1160 were reached and 1031 completed the survey). The outcomes are the level of interest in and the range of WTP for BCST. Three categories of individual factors identified in the literature were used as potential explanatory factors, that is, demographic, clinical and psychosocial. Descriptive statistics indicated that the vast majority of sampled women are interested in BCST (90%). Among those, more than half of them are willing-to-pay for such a test (57%). The regression models pointed out several factors associated with both outcomes (eg, age, income, family history, locus of control-powerful others) and marginal effects were used to highlight the most impactful factors for each outcome. The results of this study provide a proxy of the readiness of women of the general population to use and to pay for BCST. They also offer insights for developing inclusive and specific strategies to foster informed decision-making and guide the services offered by health organisations corresponding to women's preferences and needs. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. Hydrogeology of salt karst under different cap soils and climates (Persian Gulf and Zagros Mts., Iran)

    Czech Academy of Sciences Publication Activity Database

    Bruthans, J.; Kamas, J.; Filippi, Michal; Zare, M.; Mayo, A. L.

    2017-01-01

    Roč. 46, č. 2 (2017), s. 303-320 ISSN 0392-6672 R&D Projects: GA AV ČR KJB315040801 Institutional support: RVO:67985831 Keywords : diapir * salt karst * soil * arid * chemistry * isotope Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 1.439, year: 2016

  1. Jahani salt diapir, Iran: Hydrogeology, karst features and effect on surroundings environment

    Czech Academy of Sciences Publication Activity Database

    Abirifard, M.; Raeisi, E.; Zarei, M.; Zare, M.; Filippi, Michal; Bruthans, J.; Talbot, J.

    2017-01-01

    Roč. 46, č. 3 (2017), s. 445-457 ISSN 0392-6672 Institutional support: RVO:67985831 Keywords : salt diapir * brine spring * sinkhole * flow model * halite dissolution * salt karst Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 1.439, year: 2016

  2. Applications of GIS and database technologies to manage a Karst Feature Database

    Science.gov (United States)

    Gao, Y.; Tipping, R.G.; Alexander, E.C.

    2006-01-01

    This paper describes the management of a Karst Feature Database (KFD) in Minnesota. Two sets of applications in both GIS and Database Management System (DBMS) have been developed for the KFD of Minnesota. These applications were used to manage and to enhance the usability of the KFD. Structured Query Language (SQL) was used to manipulate transactions of the database and to facilitate the functionality of the user interfaces. The Database Administrator (DBA) authorized users with different access permissions to enhance the security of the database. Database consistency and recovery are accomplished by creating data logs and maintaining backups on a regular basis. The working database provides guidelines and management tools for future studies of karst features in Minnesota. The methodology of designing this DBMS is applicable to develop GIS-based databases to analyze and manage geomorphic and hydrologic datasets at both regional and local scales. The short-term goal of this research is to develop a regional KFD for the Upper Mississippi Valley Karst and the long-term goal is to expand this database to manage and study karst features at national and global scales.

  3. Going Underground: A Field Investigation and Lab Activity on Karst Topography and Water Systems

    Science.gov (United States)

    O'Dell, Gary; Gonzalez-Espada, Wilson

    2011-01-01

    Students learn science best with activities that mirror the way scientists work. This article describes how geologists investigate groundwater flow systems in areas of karst topography--geologic formations shaped by dissolving bedrock--and provides a way for students to replicate this research. Students also use electric current to model water…

  4. Characterizing the interaction of groundwater and surface water in the karst aquifer of Fangshan, Beijing (China)

    Science.gov (United States)

    Chu, Haibo; Wei, Jiahua; Wang, Rong; Xin, Baodong

    2017-03-01

    Correct understanding of groundwater/surface-water (GW-SW) interaction in karst systems is of greatest importance for managing the water resources. A typical karst region, Fangshan in northern China, was selected as a case study. Groundwater levels and hydrochemistry analyses, together with isotope data based on hydrogeological field investigations, were used to assess the GW-SW interaction. Chemistry data reveal that water type and the concentration of cations in the groundwater are consistent with those of the surface water. Stable isotope ratios of all samples are close to the local meteoric water line, and the 3H concentrations of surface water and groundwater samples are close to that of rainfall, so isotopes also confirm that karst groundwater is recharged by rainfall. Cross-correlation analysis reveals that rainfall leads to a rise in groundwater level with a lag time of 2 months and groundwater exploitation leads to a fall within 1 month. Spectral analysis also reveals that groundwater level, groundwater exploitation and rainfall have significantly similar response periods, indicating their possible inter-relationship. Furthermore, a multiple nonlinear regression model indicates that groundwater level can be negatively correlated with groundwater exploitation, and positively correlated with rainfall. The overall results revealed that groundwater level has a close correlation with groundwater exploitation and rainfall, and they are indicative of a close hydraulic connection and interaction between surface water and groundwater in this karst system.

  5. Factors affecting public-supply well vulnerability in two karst aquifers.

    Science.gov (United States)

    Musgrove, MaryLynn; Katz, Brian G; Fahlquist, Lynne S; Crandall, Christy A; Lindgren, Richard J

    2014-09-01

    Karst aquifers occur in a range of climatic and geologic settings. Nonetheless, they are commonly characterized by their vulnerability to water-quality impairment. Two karst aquifers, the Edwards aquifer in south-central Texas and the Upper Floridan aquifer in western Florida, were investigated to assess factors that control the movement of contaminants to public-supply wells (PSWs). The geochemistry of samples from a selected PSW or wellfield in each aquifer was compared with that from nearby monitoring wells and regional PSWs. Geochemistry results were integrated with age tracers, flow modeling, and depth-dependent data to refine aquifer conceptual models and to identify factors that affect contaminant movement to PSWs. The oxic Edwards aquifer is vertically well mixed at the selected PSW/wellfield, although regionally the aquifer is geochemically variable downdip. The mostly anoxic Upper Floridan aquifer is affected by denitrification and also is geochemically variable with depth. In spite of considerable differences in geology and hydrogeology, the two aquifers are similarly vulnerable to anthropogenic contamination. Vulnerability in studied PSWs in both aquifers is strongly influenced by rapid karst flowpaths and the dominance of young (aquifers (nitrate, atrazine, deethylatrazine, tetrachloroethene, and chloroform). Specific consideration of water-quality protection efforts, well construction and placement, and aquifer response times to land-use changes and contaminant loading are discussed, with implications for karst groundwater management. © 2014 The Authors. Groundwater published by Wiley Periodicals, Inc. on behalf of National Ground Water Association.

  6. Metode Tracer Test untuk Mencari Hubungan Antar Sistem Sungai Bawah Tanah Di Akuifer Karst

    Directory of Open Access Journals (Sweden)

    Harjito Harjito

    2015-08-01

    Full Text Available Problem yang umum dijumpai di kawasan karst adalah mengenai ketersediaan air, mengingat kondisi hidrologi kawasan karst yang berbeda dengan kawasan lain. Ditinjau dari sisi lain, masyarakat di sekitar kawasan rencana perluasan eksploitasi masih memanfaatkan mata air yang daerah tangkapannya berasal dari perbukitan batu gamping untuk memenuhi kebutuhan air domestik dan irigasi pertanian. Dengan demikian, perlu adanya penelitian hidrologi karst lebih lanjut terutama mengenai keberadaan sistem jaringan yang saling terhubung di dalam kawasan rencana perluasan eksploitasi dan sekitarnya. Studi ini diharapkan dapat menjadi pertimbangan terhadap kebijakan yang akan diambil sebagai upaya untuk dapat melakukan pengelolaan potensi tersebut sebaik-baiknya. Tracer test dilakukan sebagai bentuk follow-up dari survei gua dan sinkhole yang ada di sekitar area tambang. Tracer test dilakukan untuk mengetahui konektivitas aliran pada sistem gua berair dan mata air Cipintu. Berdasarkan hasil penelitian potensi debit air di Mata air Cipintu sebesar 18,55 liter/s dan mengindikasikan adanya konektivitas antara gua berair dengan Mata air Cipintu. Kata kunci : karst, hidrologi, tracer test, eksploitasi

  7. Using underground mine Karst water to solve water supply problem in underground mine

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W. [Wanbei Mining Administration (China). Liuqiao No. 2 Mine

    1995-05-01

    There is a very rich karst water resource under the Liuqiao No. 2 underground mine. Under normal mining conditions the drainage is 546 m{sup 3}/h while the maximum drainage is up to 819 m{sup 3}/h. If water inrush occurred from a broken zone of a fault or a sinkhole of the karst, the flow could be up to 3269 m{sup 3}/h. The karst water is of good quality and high in pressure. The water head pressure at -400 m level is about 3.5 MPa. To save mine construction cost, it was decided that the water supply for coal production equipment, mining operation and mine fire control was to be changed from the surface to the underground by drilling a water well to tap the karst water resource. A water well with a depth of 63.3 m was drilled in the -400 m transportation roadway. The diameter of the well is 127 mm and it has a casing pipe with a diameter of 108 mm which is connected to the water supply pipeline. The pressure of the water supply is measured at 23.5 MPa and the water flow rate is 252 m{sup 3}/h. The establishment of the water supply system has achieved great cost saving for Liuqiao No. 2 Mine. 2 figs.

  8. Hochauflösendes Monitoring von Karst-Grundwasserressourcen beiderseits des Jordangrabens - Konzepte und Anwendungsbeispiele

    Science.gov (United States)

    Schmidt, Sebastian; Grimmeisen, Felix; Ries, Fabian; Goldscheider, Nico; Sauter, Martin

    2018-03-01

    In the semi-arid eastern Mediterranean water supply is highly dependent on karst aquifers. The region is characterized by multi-year dry and wet cycles combined with high hydrological dynamics, especially during intense precipitation events. The investigated karst regions in the West Bank and Jordan are experiencing strong urbanization within the groundwater catchments and hence a rising impact on water quality. Therefore, high resolution monitoring data are required for the assessment of available water resources and the hydrogeological characterization of the karst systems. These measurements are focused on the (natural) meteorological input signals and the system output signals at the karst springs. Also soil moisture and ephemeral runoff dynamics are investigated. The monitoring data enable (1) hydrogeological characterization of the aquifers, (2) estimation of groundwater recharge via soil water balance and reservoir models, and (3) assessment of contamination dynamics in groundwater (e. g. nitrate and E. coli concentrations), allowing an optimized raw water management. Several examples illustrate the importance of high-resolution hydrological monitoring data.

  9. Multi-component and multi-array TEM detection in karst tunnels

    International Nuclear Information System (INIS)

    Sun, Huaifeng; Li, Shucai; Su, Maoxin; Xue, Yiguo; Li, Xiu; Qi, Zhipeng

    2012-01-01

    Emerging applications of transient electromagnetic methods (TEM) in tunnelling require higher resolution on the distributions and shapes of low resistivity bodies, such as karst water and karst pipes, using multi-component and multi-array receivers. However, there are no apparent resistivity definitions for both vertical and horizontal components with offsets inside the loop. Although the raw field can show the differences of the earth electric structure, it is not straightforward. Apparent resistivity is very convenient and easy for engineers. We have developed a method for multi-component and multi-array TEM which can be applied in tunnelling and defined the expressions of apparent resistivity. This method takes advantage of the difference in resolution among components. A homogeneous half-space model and four typical three-layered models are used to test the effectiveness of the new definition. A field case history is carried out and analysed to demonstrate the viability of this technique. The results suggest that it is feasible to use the technique in tunnelling, especially for identifying the spatial distribution of karst water and karst pipes. (paper)

  10. Stable sulfur and oxygen isotopes as geochemical tracers of sulfate in karst waters

    Science.gov (United States)

    Sun, Jing; Kobayashi, Tatsuaki; Strosnider, William H. J.; Wu, Pan

    2017-08-01

    Karst water resources, which are extremely sensitive to mining activities, are critical for the support of human societies and ecological systems in many regions worldwide. In order to determine the sources and fate of dissolved sulfate in low-pH karst waters, hydrochemical variations of karst waters with and without acid mine drainage (AMD) impacts were investigated along with stable isotope dynamics. As expected, hydrochemical characteristics and isotopic compositions of the AMD and AMD-downstream water (ADW) were dramatically different from that of the non-AMD-impacted water (NAW). The sources of sulfur isotopes in sulfate were predominantly pyrite oxidation for the AMD and ADW, and atmospheric deposition for the NAW. Based on the general isotope-balance model, the relative proportions of sulfate oxygen derived from water and air were calculated. The mean proportion of sulfate oxygen derived from water in ADW was roughly double that of AMD. This suggests that the sulfate associated with AMD is predominantly influenced by aerobic pyrite oxidation, while that of ADW is likely affected by the dissolution of pyrite under anaerobic conditions in reservoir sediment. This observation was coincident with the noted variations of hydrochemical characteristics and was supported by principal component analysis. These results provide a better understanding of how stable isotopes of sulfate and water can be used to track mining contamination in karst aquifers, which could benefit remediation planning for these distinctive systems.

  11. Microbial diversity and impact on carbonate geochemistry across a changing geochemical gradient in a karst aquifer.

    Science.gov (United States)

    Gray, Cassie J; Engel, Annette S

    2013-02-01

    Although microbes are known to influence karst (carbonate) aquifer ecosystem-level processes, comparatively little information is available regarding the diversity of microbial activities that could influence water quality and geological modification. To assess microbial diversity in the context of aquifer geochemistry, we coupled 16S rRNA Sanger sequencing and 454 tag pyrosequencing to in situ microcosm experiments from wells that cross the transition from fresh to saline and sulfidic water in the Edwards Aquifer of central Texas, one of the largest karst aquifers in the United States. The distribution of microbial groups across the transition zone correlated with dissolved oxygen and sulfide concentration, and significant variations in community composition were explained by local carbonate geochemistry, specifically calcium concentration and alkalinity. The waters were supersaturated with respect to prevalent aquifer minerals, calcite and dolomite, but in situ microcosm experiments containing these minerals revealed significant mass loss from dissolution when colonized by microbes. Despite differences in cell density on the experimental surfaces, carbonate loss was greater from freshwater wells than saline, sulfidic wells. However, as cell density increased, which was correlated to and controlled by local geochemistry, dissolution rates decreased. Surface colonization by metabolically active cells promotes dissolution by creating local disequilibria between bulk aquifer fluids and mineral surfaces, but this also controls rates of karst aquifer modification. These results expand our understanding of microbial diversity in karst aquifers and emphasize the importance of evaluating active microbial processes that could affect carbonate weathering in the subsurface.

  12. Hydrograph monitoring and analysis for sustainable karst water management in Nyadeng Spring, East Borneo

    Science.gov (United States)

    Widyastuti, M.; Fatchurohman, H.; Fathoni, W. A.; Hakim, A. A.; Haryono, E.

    2018-04-01

    Karst aquifer stores abundant water resources within its matrix, conduits, and intergranular pores. Karst aquifer plays an important role in providing water supply, especially in the areas nearby that commonly dry and lack of surface water resources. Karst spring hydrograph analysis is very fundamental step to–assess and determines the condition of the catchment area in karst terrain. Recession curve is believed to be the most stable part in single flood hydrograph that represents the aquifer characteristics. Nyadeng is one of the most significant karst springs that located in Merabu Karst Area, East Borneo. Villagers in Merabu highly depend on Nyadeng Spring for fulfilled their freshwater need. Hydrograph monitoring has been initiated for one year in Nyadeng Spring as a preliminary action for karst water management in Merabu. Water level data series obtained using automatic water level data logger and then correlated with manual discharge measurement to generate stage-discharge rating curve. The stage-discharge rating curve formula for Nyadeng Spring calculated as y = 0,0102e5,8547x with r2 value = 0.8759. From the combination of several single flood events, Master Recession Curve (MRC) was generated to determine flow regime as the main consideration for karstification degree calculation. From the MRC result, flow regimes formula determined as Qt = 3.2-0.001t + 1.2(1-0.012t)+1.6(1-0.035t) indicated that one sub-regime with laminar flow and two sub-regimes with turbulent flow existed. From the MRC formula, the degree of karstification in Nyadeng Spring classified at seventh scale (developed karstification of the aquifer) based on Malik’s karstification degree (2012). The degree of karstification in Nyadeng Spring indicates that the aquifer formed by large conduit channels, fissures, and macro fissures which are able to provide significant water sources that can be utilized for multi purposes. Therefore, it is concluded that spring hydrograph monitoring provide

  13. Physical and Hydrological Meaning of the Spectral Information from Hydrodynamic Signals at Karst Springs

    Science.gov (United States)

    Dufoyer, A.; Lecoq, N.; Massei, N.; Marechal, J. C.

    2017-12-01

    Physics-based modeling of karst systems remains almost impossible without enough accurate information about the inner physical characteristics. Usually, the only available hydrodynamic information is the flow rate at the karst outlet. Numerous works in the past decades have used and proven the usefulness of time-series analysis and spectral techniques applied to spring flow, precipitations or even physico-chemical parameters, for interpreting karst hydrological functioning. However, identifying or interpreting the karst systems physical features that control statistical or spectral characteristics of spring flow variations is still challenging, not to say sometimes controversial. The main objective of this work is to determine how the statistical and spectral characteristics of the hydrodynamic signal at karst springs can be related to inner physical and hydraulic properties. In order to address this issue, we undertake an empirical approach based on the use of both distributed and physics-based models, and on synthetic systems responses. The first step of the research is to conduct a sensitivity analysis of time-series/spectral methods to karst hydraulic and physical properties. For this purpose, forward modeling of flow through several simple, constrained and synthetic cases in response to precipitations is undertaken. It allows us to quantify how the statistical and spectral characteristics of flow at the outlet are sensitive to changes (i) in conduit geometries, and (ii) in hydraulic parameters of the system (matrix/conduit exchange rate, matrix hydraulic conductivity and storativity). The flow differential equations resolved by MARTHE, a computer code developed by the BRGM, allows karst conduits modeling. From signal processing on simulated spring responses, we hope to determine if specific frequencies are always modified, thanks to Fourier series and multi-resolution analysis. We also hope to quantify which parameters are the most variable with auto

  14. A model of karst systems of the Usturt plateau (Middle Asia); Un modelo de sistemas karsticos de la meseta Usturt (Asia central)

    Energy Technology Data Exchange (ETDEWEB)

    Victorov, A. S.

    2016-07-01

    The issues relating to the structure and development of desert karst is currently one of the least studied problems. The goal of the research efforts presented in this paper was to create a model of karst systems in the Usturt Plateau and, primarily, of the systems formed by the prevailing numerous surface karst landforms. The model is based on the following main assumptions: the process of emergence of the karst phenomena is probabilistic and occurs independently at non-intersecting sites; the probability of emergence of one depression at a reference site depends only on its area. The increase of the dimensions of a karst landform is a random process that occurs independently of other karst landforms, its speed is governed by random factors, and it is directly proportionate to the existing dimensions of the landform. The model does not assume constancy of climatic characteristics. The testing was conducted at several reference sites of the Usturt Plateau. The research allowed us to reach the following conclusions: the karst depressions of the Usturt Plateau, which are the typical forms of desert karst, are governed by the Poisson distribution of their centres and by the lognormal distribution of their dimensions, similar to the karst depressions in a humid climate. The results may be used in assessments of karst hazard for linear and areal structures, as well as for small-dimensional structures. (Author)

  15. Localities With Elevated Radiation Background in the High Karst Zone of Montenegro

    International Nuclear Information System (INIS)

    Vukotic, P.; Svrkota, R.; Andjelic, T.; Zekic, R.; Antovic, N.

    2011-01-01

    Research aimed to find localities in Montenegro with an elevated terrestrial gamma background was conducted during the period 2008-2009. For this purpose, 138 localities which have geological formations known to contain minerals with potentially high concentrations of U, Th and K, were selected throughout the country for a dosimetric survey. There are four distinctive geotectonic units in Montenegro: the Adriatic-Ionian Zone (JZ), the Budva-Cukali Zone (BZ), the High Karst Zone (VK), and the Durmitor Tectonic Unit (DTJ). The central and southern parts of Montenegro belong to the VK zone, whose geological structure is predominated by Mesozoic carbonate sediments, with occurrences of red and white bauxite formations, Triassic volcanic rocks, Paleogene flysch sediments and Quaternary sediments. In total, 38 localities belonging to the VK zone were selected for field investigations of terrestrial radiation. Knowing from earlier investigations that in Montenegro the average absorbed dose-rate in the air, 1 m above the ground, is 55 nGy/h, it was arbitrarily adopted that only localities with absorbed doses at least 50 % above this average value would be considered as having a relatively elevated radiation background. Field measurements have shown that 12 of the surveyed localities in the VK zone have such elevated dose values, five of them being with the highest dose rates in Montenegro. Among these five sites, the highest dose rate (192 nGy/h) was found at a locality which lies on andesite volcanic rock, while the other four localities (131 - 149 nGy/h) lie on bauxite deposits. Compared to the other areas in the world known to have a high natural radiation background, all of these localities in Montenegro have a moderately elevated radiation level. From the 12 localities with a relatively elevated radiation background, soil samples have been collected and analyzed by gamma spectrometry to determine activity concentrations of 40K, 232Th, 235U, 238U, 226Ra and 137Cs

  16. Evaluation of Karst Soil Erosion and Nutrient Loss Based on RUSLE Model in Guizhou Province

    Science.gov (United States)

    Zeng, Cheng; Li, Yangbing; Bai, Xiaoyong; Luo, Guangjie

    2018-01-01

    Based on GIS technology and RUSLE model, the spatial variation characteristics of soil erosion were analyzed in karst areas, and the relationship between soil erosion and soil nutrient loss was discussed. The results showed that the soil differences in spatial variation between nutrient losses. The results illustrate the total soil erosion in is 10316.31 × 104t • a-1, accounting for 84.95% of the total land area in Guizhou Province. The spatial distribution of soil erosion showing the characteristics of the southeast to the northwest strip. The annual average soil erosion modulu is 691.94 t • km-2 • a-1, of which karst is 720.28t • km-2 • a-1 and non-karst is 689.53 t • km-2 • a-1. The total nutrient losses such as soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) were 596.72 × 104t • a-1 due to soil erosion, and SOC, TN and TP and TK were 38.13, 1.61, 0.41 and 14.70t • km-2 • a-1, respectively. The average amount of loss and total loss are the largest in non-karst, and four kinds of nutrient is the smallest in karst gorge. The spatial variation of soil erosion in the study area is the process of increasing the erosion area with the increase of the erosion rate, and the difference of the spatial distribution of soil erosion determines the spatial distribution of soil nutrient loss.

  17. Runoff response to climate change and human activities in a typical karst watershed, SW China

    Science.gov (United States)

    Xu, Yan; Wang, Shijie; Shu, Dongcai; Tian, Yichao

    2018-01-01

    This study aims to reveal the runoff variation characteristics of long time series in a karst region, analyse comprehensively its different driving factors, and estimate quantitatively the contribution rates of climate change and human activities to net runoff variation. Liudong river basin, a typical karst watershed in southwest China, is the study site. Statistical methods, such as linear fitting, the Morlet wavelet analysis, normalized curve and double mass curve, are applied to analyse the runoff of the watershed. Results show that the runoff in the karst watershed during the research period exhibits a three-stage change and the abrupt change points are the years 1981 and 2007: (1) 1968–1980, the runoff initially exhibited a trend of sustained decreasing and then an abrupt fluctuation. The runoff was obviously destroyed through precipitation-producing processes. Improper land utilisation and serious forest and grass destruction intensified the fluctuation variation amplitude of the runoff. (2) 1981–2006, the changing processes of runoff and precipitation exhibited good synchronism. Precipitation significantly affected runoff variation and human activities had a slight interference degree. (3) 2007–2013, the fluctuation range of runoff was considerably smaller than that of precipitation. The significant growth of forest and grassland areas and the increase in water consumption mitigated runoff fluctuation and greatly diminished runoff variation amplitude. According to calculation, the relative contribution rates of precipitation and human activities to net runoff variation with 1981–2007 as the reference period were −81% and 181% in average, respectively, during 1968–1980, and −117% and 217% in average, respectively, during 2007–2013. In general, the analysis of runoff variation trend and of the contribution rate of its main influencing factors in the typical karst watershed for nearly half a century may be significant to solve the drought

  18. Runoff response to climate change and human activities in a typical karst watershed, SW China.

    Science.gov (United States)

    Xu, Yan; Wang, Shijie; Bai, Xiaoyong; Shu, Dongcai; Tian, Yichao

    2018-01-01

    This study aims to reveal the runoff variation characteristics of long time series in a karst region, analyse comprehensively its different driving factors, and estimate quantitatively the contribution rates of climate change and human activities to net runoff variation. Liudong river basin, a typical karst watershed in southwest China, is the study site. Statistical methods, such as linear fitting, the Morlet wavelet analysis, normalized curve and double mass curve, are applied to analyse the runoff of the watershed. Results show that the runoff in the karst watershed during the research period exhibits a three-stage change and the abrupt change points are the years 1981 and 2007: (1) 1968-1980, the runoff initially exhibited a trend of sustained decreasing and then an abrupt fluctuation. The runoff was obviously destroyed through precipitation-producing processes. Improper land utilisation and serious forest and grass destruction intensified the fluctuation variation amplitude of the runoff. (2) 1981-2006, the changing processes of runoff and precipitation exhibited good synchronism. Precipitation significantly affected runoff variation and human activities had a slight interference degree. (3) 2007-2013, the fluctuation range of runoff was considerably smaller than that of precipitation. The significant growth of forest and grassland areas and the increase in water consumption mitigated runoff fluctuation and greatly diminished runoff variation amplitude. According to calculation, the relative contribution rates of precipitation and human activities to net runoff variation with 1981-2007 as the reference period were -81% and 181% in average, respectively, during 1968-1980, and -117% and 217% in average, respectively, during 2007-2013. In general, the analysis of runoff variation trend and of the contribution rate of its main influencing factors in the typical karst watershed for nearly half a century may be significant to solve the drought problem in the karst

  19. Evaluating disturbance on mediterranean karst areas: the example of Sardinia (Italy)

    Science.gov (United States)

    de Waele, Jo

    2009-07-01

    Evaluating the human disturbance on karst areas is a difficult task because of the complexity of these peculiar and unique environments. The human impact on karstic geo-ecosystems is increasingly important and there is an increasing need for multidisciplinary tools to assess the environmental changes in karst areas. Many disciplines, such as biology, geomorphology, hydrology and social-economical sciences are to be considered to sufficiently evaluate the impact on these intrinsically vulnerable areas. This article gives an overview of the evolution of environmental impact on karst areas of the island Sardinia (Italy). For this particular case, the most important impacts in the past 50 years are derived from the following activities, in decreasing importance: (1) mining and quarrying; (2) deforestation, agriculture and grazing; (3) building (widespread urbanisation, isolated homes, etc.) and related infrastructures (roads, sewer systems, aqueducts, waste dumps, etc.); (4) tourism; (5) military activities. To evaluate the present environmental state of these areas the Disturbance Index for Karst environments [Van Beynen and Townsend (Environ Manage 36:101-116)] is applied in a slightly modified version. Instead of considering the indicators of environmental disturbances used in the original method, this slightly modified index evaluates the disturbances causing the deterioration of the environmental attributes. In the Sardinian case study, 27 disturbances have been evaluated, giving rise to the definition of a Disturbance Index ranging between 0 (Pristine) and 1 (highly disturbed). This Disturbance Index simplifies the original KDI method, appears to adequately measure disturbance on Mediterranean karst areas and could be applied with success to other similar regions.

  20. Characterization of the porosity distribution in the upper part of the karst Biscayne aquifer using common offset ground penetrating radar, Everglades National Park, Florida

    Science.gov (United States)

    Mount, Gregory J.; Comas, Xavier; Cunningham, Kevin J.

    2014-07-01

    The karst Biscayne aquifer is characterized by a heterogeneous spatial arrangement of porosity and hydraulic conductivity, making conceptualization difficult. The Biscayne aquifer is the primary source of drinking water for millions of people in south Florida; thus, information concerning the distribution of karst features that concentrate the groundwater flow and affect contaminant transport is critical. The principal purpose of the study was to investigate the ability of two-dimensional ground penetrating radar (GPR) to rapidly characterize porosity variability in the karst Biscayne aquifer in south Florida. An 800-m-long GPR transect of a previously investigated area at the Long Pine Key Nature Trail in Everglades National Park, collected in fast acquisition common offset mode, shows hundreds of diffraction hyperbolae. The distribution of diffraction hyperbolae was used to estimate electromagnetic (EM) wave velocity at each diffraction location and to assess both horizontal and vertical changes in velocity within the transect. A petrophysical model (complex refractive index model or CRIM) was used to estimate total bulk porosity. A set of common midpoint surveys at selected locations distributed along the common-offset transect also were collected for comparison with the common offsets and were used to constrain one-dimensional (1-D) distributions of porosity with depth. Porosity values for the saturated Miami Limestone ranged between 25% and 41% for common offset GPR surveys, and between 23% and 39% for common midpoint GPR surveys. Laboratory measurements of porosity in five whole-core samples from the saturated part of the aquifer in the study area ranged between 7.1% and 41.8%. GPR estimates of porosity were found to be valid only under saturated conditions; other limitations are related to the vertical resolution of the GPR signal and the volume of the material considered by the measurement methodology. Overall, good correspondence between GPR estimates and

  1. Nutrient pressures and legacies in a small agricultural karst catchment

    Science.gov (United States)

    Fenton, Owen; Mellander, Per-Erik; Daly, Karen; Wall, David P.; Jahangir, Mohammad M.; Jordan, Phil; Hennessey, Deirdre; Huebsch, Manuela; Blum, Philipp; Vero, Sara; Richards, Karl G.

    2017-04-01

    Catchments with short subsurface hydrologic time lags are commonly at risk for leached losses of nitrogen (N) and phosphorus (P). Such catchments are suitable for testing the efficacy of mitigation measures as management changes. In some sites, however, N and P may be retained in the soil and subsoil layers, and then leached, mobilised or attenuated over time. This biogeochemical time lag may therefore have enduring effects on the water quality. The aim of this study was to improve the understanding of N and P retention, attenuation and distribution of subsurface pathway in an intensively managed agricultural karst catchment with an oxidised aquifer setting, and also to inform how similar sites can be managed in the future. Results showed that in the years pre-2000 slurry from an on-site integrated pig production unit had been applied at rates of 33 t/ha annually, which supplied approximately 136 kg/ha total N and approximately 26 kg/ha total P annually. This practice contributed to large quantities of N (total N and NH4-N) and elevated soil test P (Morgan extractable P), present to a depth of 1 m. This store was augmented by recent surpluses of 263 kg N/ha, with leached N to groundwater of 82.5 kg N/ha and only 2.5 kg N/ha denitrified in the aquifer thereafter. Sub hourly spring data showed the largest proportion of N loss from small (54-88%) and medium fissure pathways (7- 21%) with longer hydrologic time lags, with smallest loads from either large fissure (1-13%) or conduit (1-10%) pathways with short hydrologic time lags (reaction time at the spring from onset of a rainfall event is within hours). Although soils were saturated in P and in mobile forms to 0.5 m, dissolved reactive P concentrations in groundwater remained low due to Ca and Mg limestone chemistry. Under these conditions a depletion of the legacy store, with no further inputs, would take approximately 50 years and with NO3-N concentrations in the source area dropping to levels that could sustain

  2. Implicit User Interest Profile

    CERN Document Server

    Chan, K

    2002-01-01

    User interest profile presents items that the users are interested in. Typically those items can be listed or grouped. Listing is good but it does not possess interests at different abstraction levels - the higher-level interests are more general, while the lower-level ones are more specific. Furthermore, more general interests, in some sense, correspond to longer-term interests, while more specific interests correspond to shorter-term interests. This hierarchical user interest profile has obvious advantages: specifying user's specific interests and general interests and representing their relationships. Current user interest profile structures mostly do not use implicit method, nor use an appropriate clustering algorithm especially for conceptually hierarchical structures. This research studies building a hierarchical user interest profile (HUIP) and the hierarchical divisive algorithm (HDC). Several users visit hundreds of web pages and each page is recorded in each users profile. These web pages are used t...

  3. A Matter of Interest

    Science.gov (United States)

    Scott, Paul

    2009-01-01

    In these days of financial turmoil, there is greater interest in depositing one's money in the bank--at least one might hope for greater interest. Banks and various trusts pay compound interest at regular intervals: this means that interest is paid not only on the original sum deposited, but also on previous interest payments. This article…

  4. Groundwater recharge assessment at local and episodic scale in a soil mantled perched karst aquifer in southern Italy

    Science.gov (United States)

    Allocca, V.; De Vita, P.; Manna, F.; Nimmo, John R.

    2015-01-01

    Groundwater recharge assessment of karst aquifers, at various spatial and temporal scales, is a major scientific topic of current importance, since these aquifers play an essential role for both socio-economic development and fluvial ecosystems.

  5. Changes in Chemical and Isotopic Composition of Groundwater during Long-Term Pumping Test in Brestovica Karst Aquifer

    International Nuclear Information System (INIS)

    Mezga, Kim; Urbanc, Janko

    2011-01-01

    The main aim of the experimental pumping test, which was carried out in the dry summer period in August 2008 for 30 days, was to assess the groundwater resource quantity which could be pumped at the time of the highest water needs for the Slovene Coast and Karst areas. Further, we wanted to test the chemical status of groundwater to assure its suitability for further use and to assess the influence of the Soca River aquifer on this karst aquifer

  6. The cost of karst subsidence and sinkhole collapse in the United States compared with other natural hazards

    Science.gov (United States)

    Weary, David J.

    2015-01-01

    Rocks with potential for karst formation are found in all 50 states. Damage due to karst subsidence and sinkhole collapse is a natural hazard of national scope. Repair of damage to buildings, highways, and other infrastructure represents a significant national cost. Sparse and incomplete data show that the average cost of karst-related damages in the United States over the last 15 years is estimated to be at least $300,000,000 per year and the actual total is probably much higher. This estimate is lower than the estimated annual costs for other natural hazards; flooding, hurricanes and cyclonic storms, tornadoes, landslides, earthquakes, or wildfires, all of which average over $1 billion per year. Very few state organizations track karst subsidence and sinkhole damage mitigation costs; none occurs at the Federal level. Many states discuss the karst hazard in their State hazard mitigation plans, but seldom include detailed reports of subsidence incidents or their mitigation costs. Most State highway departments do not differentiate karst subsidence or sinkhole collapse from other road repair costs. Amassing of these data would raise the estimated annual cost considerably. Information from insurance organizations about sinkhole damage claims and payouts is also not readily available. Currently there is no agency with a mandate for developing such data. If a more realistic estimate could be made, it would illuminate the national scope of this hazard and make comparison with costs of other natural hazards more realistic.

  7. The Influence od Air Temperature and Barometric Pressure on Radon and Carbon Dioxide Levels in Air of a Karst Cave

    International Nuclear Information System (INIS)

    Obu, K.; Cencur Curk, B.; Gregoric, A.; Smerajec, M.; Vaupotic, J.; Fujiyoshi, R.; Sakuta, Y.

    2011-01-01

    Radioactive noble gas radon (222Rn) is created in minerals by radioactive transformation of 226Ra within the 238U natural decay chain. It migrates through the ground, accumulates in underground rooms (e. g., karst caves) and eventually enters the atmosphere. It is always present in our living and working environment. Because of its harmful health effect, it presents a serious social concern but is, on the other hand, a useful tool in several scientific disciplines. It is thus used as a tracer in exploring movement of air masses and an indicator of tectonic faults. Another minor constituent of air is carbon dioxide. Similar as radon, it is dangerous at high levels, but its presence in air of karst caves is indispensable for their life, because it governs speleogenetic processes. In the cave air, its concentration is determined by the inflow of outside air, biogenic activity of soil, degradation of organic matter and carbonate, degassing from water, and human activity. Therefore, ventilation of the cave is crucial for its conservation. Based on temporal variations of radon and carbon dioxide levels, ventilation regime in the cave can be estimated. Radon has been surveyed in all the twenty show caves and in thirty other caves in Slovenia, with emphasis on the Postojna Cave. In the present study, in addition to radon, monitoring of carbon dioxide was introduced for the first time. The Kostanjevica Cave, situated in southern Slovenia in an isolated island of karst, was selected because it is crossed by a tectonic fault at which measurements of three-dimensional micro displacements are underway. Because of the fault, high levels of radon and carbon dioxide were expected. In this paper, measurements are described and both the spatial and time variations of radon and carbon dioxide levels are presented and commented on. Continuous radon monitoring was carried out with the RadonScout devices (Sarad, Germany) from April to December 2009, with several interruptions because of

  8. Nitrogen loss from karst area in China in recent 50 years: An in-situ simulated rainfall experiment's assessment.

    Science.gov (United States)

    Song, Xianwei; Gao, Yang; Green, Sophie M; Dungait, Jennifer A J; Peng, Tao; Quine, Timothy A; Xiong, Bailian; Wen, Xuefa; He, Nianpeng

    2017-12-01

    Karst topography covers more than 1/3 of the People's Republic of China in area. The porous, fissured, and soluble nature of the underlying karst bedrock (primarily dolomite and limestone) leads to the formation of underground drainage systems. Karst conduit networks dominate this system, and rainfall takes a crucial role on water cycle at China karst area. Nitrogen loss from the karst system is of particular concern, with regard to nutrient use efficiency as well as water quality, as much of the karst system, including steeply sloping terrain, is used for intensive agriculture. We use simulated rainfall experiments to determine the relationship between rainfall and nitrogen loss at typical karst slope land and then estimate nitrogen loss from the karst soil. The results show that both surface runoff and subsurface runoff have a significant linear correlation with rainfall at all studied sites. Subsurface runoff is larger than surface runoff at two karst sites, while the opposite is true at the non-karst site. Exponential function satisfactorily described the correlation between rainfall and nitrogen concentrations in runoff. Nitrates accounted for 60%-95% of the dissolved nitrogen loss (DN, an index of N-loss in this research). The estimated annual N-loss load varies between 1.05 and 1.67 Tg N/year in the whole karst regions of China from 1961 to 2014. Approximately, 90% of the N-loss load occurred during the wet season, and 90% of that passed through the subsurface. Understanding the processes and estimating N-loss is highly valuable in determining long-term soil security and sustainability in karst regions.

  9. Chemical characterization and antioxidant activity of Amazonian (Ecuador) Caryodendron orinocense Karst. and Bactris gasipaes Kunth seed oils.

    Science.gov (United States)

    Radice, Matteo; Viafara, Derwin; Neill, David; Asanza, Mercedes; Sacchetti, Gianni; Guerrini, Alessandra; Maietti, Silvia

    2014-01-01

    Nowadays, data concerning the composition of Caryodendron orinocense Karst. (Euphorbiaceae) and Bactris gasipaes Kunth (Arecaceae) seed oils are lacking. In light of this fact, in this paper fatty acids and unsaponifiable fraction composition have been determined using GC-MS, HPLC-DAD (Diode Array Detector), NMR approaches and possible future applications have been preliminary investigated through estimation of antioxidant activity, performed with DPPH test. For C. orinocense linoleic acid (85.59%) was the main component, lauric (33.29%) and myristic (27.76%) acids were instead the most abundant in B. gasipaes. C. orinocense unsaponifiable fraction (8.06%) evidenced a remarkable content of β-sitosterol, campesterol, stigmasterol, squalene and vitamin E (816 ppm). B. gasipaes revealed instead β-sitosterol and squalene as main constituents of unsaponifiable matter (3.01%). Antioxidant capacity evidenced the best performance of C. orinocense seed oil. These preliminary results could be interesting to suggest the improvement of the population's incomes from Amazonian basin. In particular the knowledge of chemical composition of C. orinocense and B. gasipaes oils could be helpful to divulge and valorize these autochthones plants.

  10. Identifying orchid hotspots for biodiversity conservation in Laos: the limestone karst vegetation of Vang Vieng District, Vientiane Province

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar

    2016-10-01

    Full Text Available A project to study the phytodiversity of the Indo-Burma Biodiversity Hotspot (IBBH was initiated by Kadoorie Farm and Botanic Garden, Hong Kong, in 2011, with the aim of surveying primary forest fragments and identifying conservation priorities within this expansive but highly threatened ecoregion. Vang Vieng District of Vientiane Province, northern Laos, was chosen as a focus for a pilot expedition, since it features an extensive karst landscape that has barely been explored. Together with officials from the Ministry of Science and Technology, Government of Lao PDR, surveys of three sites were conducted in April 2012, at the end of the dry northeast monsoon season. Emphasis was placed on Orchidaceae because it is among the most species-rich and commercially exploited flowering plant families in the region. A total of 179 specimens were collected, of which approximately 135 were unique taxa accounting for 29.6% of the orchids found in Laos and 5.8% of those found in IBBH as a whole, and equivalent to 0.27 species/hectare within the area surveyed, substantially higher than published figures for other limestone areas in the region, such as Cuc Phuong National Park in Vietnam (0.0055 species/hectare and Perlis State in Peninsular Malaysia (0.0036 species/hectare.  At least one is a species new to science, nine represent new distributional records for Laos and a further nine are new records for Vientiane Province. A list of the species encountered during the study is presented and the significance of the findings is discussed. Major threats to the natural environment in northern Laos are highlighted.

  11. Interest rate derivatives

    DEFF Research Database (Denmark)

    Svenstrup, Mikkel

    This Ph.D. thesis consists of four self-contained essays on valuation of interest rate derivatives. In particular derivatives related to management of interest rate risk care are considered.......This Ph.D. thesis consists of four self-contained essays on valuation of interest rate derivatives. In particular derivatives related to management of interest rate risk care are considered....

  12. Seismic Characterization of Hypogenic Karst Systems Associated with Deep Hydrothermal Fluids in the Middle-Lower Ordovician Yingshan Formation of the Shunnan Area, Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Hongtao Zhu

    2017-01-01

    Full Text Available Two fundamental forms of hypogenic karst systems (lateral stratiform hypogenic and cross-formational fault-vein hypogenic karst system are distinguished mainly by differential effects of preexisting faults. In seismic cross sections, hypogenic karst systems are expressed as complex string-beads-like seismic reflections associated with faults. In this study, a new seismic characterization workflow was developed including seismic amplitude thresholding, fault interpretation, pickup, and merge display to enhance the description of the spatial distribution and coupling of hypogenic karst system and faults. The results suggest that the lateral stratiform hypogenic karst systems are predominantly developed at the top of the secondary faults, presenting an overall of “layered distribution and finger-like interaction” features. The cross-formational fault-vein hypogenic karst systems are developed around faults and characterized by dendritic distribution. Furthermore, we infer that the development pattern of hypogenic karst systems has been produced by the interplay of the faults, preexisting epigenic karst systems, and lateral carrier-beds, which together combine the complex hydrothermal migration pathways of fluids with the characteristics of vertical and horizontal combined pathways. In addition, some possible controlling factors (e.g., sequence stratigraphic boundaries, paleogeomorphology, and sedimentary facies that can influence the development of these hypogenic karst systems have been discussed in detail.

  13. Assessment of the potential for karst in the Rustler Formation at the WIPP site

    International Nuclear Information System (INIS)

    Lorenz, John Clay

    2006-01-01

    This report is an independent assessment of the potential for karst dissolution in evaporitic strata of the Rustler Formation at the Waste Isolation Pilot Plant (WIPP) site. Review of the available data suggests that the Rustler strata thicken and thin across the area in depositional patterns related to lateral variations in sedimentary accommodation space and normal facies changes. Most of the evidence that has been offered for the presence of karst in the subsurface has been used out of context, and the different pieces are not mutually supporting. Outside of Nash Draw, definitive evidence for the development of karst in the Rustler Formation near the WIPP site is limited to the horizon of the Magenta Member in drillhole WIPP-33. Most of the other evidence cited by the proponents of karst is more easily interpreted as primary sedimentary structures and the localized dissolution of evaporitic strata adjacent to the Magenta and Culebra water-bearing units. Some of the cited evidence is invalid, an inherited baggage from studies made prior to the widespread knowledge of modern evaporite depositional environments and prior to the existence of definitive exposures of the Rustler Formation in the WIPP shafts. Some of the evidence is spurious, has been taken out of context, or is misquoted. Lateral lithologic variations from halite to mudstone within the Rustler Formation under the WIPP site have been taken as evidence for the dissolution of halite such as that seen in Nash Draw, but are more rationally explained as sedimentary facies changes. Extrapolation of the known karst features in Nash Draw eastward to the WIPP site, where conditions are and have been significantly different for half a million years, is unwarranted. The volumes of insoluble material that would remain after dissolution of halite would be significantly less than the observed bed thicknesses, thus dissolution is an unlikely explanation for the lateral variations from halite to mudstone and siltstone

  14. Assessment of the potential for karst in the Rustler Formation at the WIPP site.

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, John Clay

    2006-01-01

    This report is an independent assessment of the potential for karst dissolution in evaporitic strata of the Rustler Formation at the Waste Isolation Pilot Plant (WIPP) site. Review of the available data suggests that the Rustler strata thicken and thin across the area in depositional patterns related to lateral variations in sedimentary accommodation space and normal facies changes. Most of the evidence that has been offered for the presence of karst in the subsurface has been used out of context, and the different pieces are not mutually supporting. Outside of Nash Draw, definitive evidence for the development of karst in the Rustler Formation near the WIPP site is limited to the horizon of the Magenta Member in drillhole WIPP-33. Most of the other evidence cited by the proponents of karst is more easily interpreted as primary sedimentary structures and the localized dissolution of evaporitic strata adjacent to the Magenta and Culebra water-bearing units. Some of the cited evidence is invalid, an inherited baggage from studies made prior to the widespread knowledge of modern evaporite depositional environments and prior to the existence of definitive exposures of the Rustler Formation in the WIPP shafts. Some of the evidence is spurious, has been taken out of context, or is misquoted. Lateral lithologic variations from halite to mudstone within the Rustler Formation under the WIPP site have been taken as evidence for the dissolution of halite such as that seen in Nash Draw, but are more rationally explained as sedimentary facies changes. Extrapolation of the known karst features in Nash Draw eastward to the WIPP site, where conditions are and have been significantly different for half a million years, is unwarranted. The volumes of insoluble material that would remain after dissolution of halite would be significantly less than the observed bed thicknesses, thus dissolution is an unlikely explanation for the lateral variations from halite to mudstone and siltstone

  15. [Relationships between soil and rocky desertification in typical karst mountain area based on redundancy analysis].

    Science.gov (United States)

    Long, Jian; Liao, Hong-Kai; Li, Juan; Chen, Cai-Yun

    2012-06-01

    Redundancy analysis (RDA) was employed to reveal the relationships between soil and rocky desertification through vegetation investigation and analysis of soil samples collected in typical karst mountain area of southwest Guizhou Province. The results showed that except TP, TK and ACa, all other variables including SOC, TN, MBC, ROC, DOC, available nutrients and basal respiration showed significant downward trends during the rocky desertification process. RDA results showed significant correlations between different types of desertification and soil variables, described as non-degraded > potential desertification > light desertification > moderate desertification > severe desertification. Moreover, RDA showed that using SOC, TN, AN, and BD as soil indicators, 74.4% of the variance information on soil and rocky desertification could be explained. Furthermore, the results of correlation analysis showed that soil variables were significantly affected by surface vegetation. Considering the ecological function of the aboveground vegetation and the soil quality, Zanthoxylum would be a good choice for restoration of local vegetation in karst mountain area.

  16. USGS geologic Mapping and karst research in the Ozark National Scenic Riverways, Missouri, USA

    Science.gov (United States)

    Weary, David J.; Grant, Victoria M

    2014-01-01

    The Ozark National Scenic Riverways (ONSR) was created in 1964 to protect 134 miles of the Current River and its major tributary, the Jacks Fork, that are located in south-central Missouri (fig. 1). The park includes numerous large karst springs including Big Spring, by flow volume this is the largest spring in the National Park system. The National Park Service (NPS) administers a narrow, nearly continuous corridor of land adjacent to the two rivers. Base flow for the rivers is chiefly supplied by groundwater that has traveled through the karst landscape from as far as 38 miles away from the spring (Imes and Frederick, 2002). The watershed is vulnerable to pollution, but the area remains largely rural with few industries. The springs and rivers provide habitat for numerous aquatic species as well as recreational resources for floaters, fishermen, and campers. The ONSR is a major cave park with hundreds of known caves and diverse in-cave resources.

  17. Distribution of polycyclic aromatic hydrocarbons in Datuo karst Tiankeng of South China.

    Science.gov (United States)

    Theodore, Oramah I; Qi, Shihua; Kong, Xiangsheng; Liu, Huafeng; Li, Jun; Li, Jie; Wang, Xiangqing; Wang, Yinhui

    2008-10-01

    Levels of polycyclic aromatic hydrocarbons (PAHs) were measured in surface soils of Datuo karst Tiankeng (large sinkholes) in South China with the use of a gas chromatography-mass spectroscopy (GC-MS) system. This paper provides data on the levels and distribution of PAHs from the top to the bottom of the Datuo karst Tiankeng. The results showed that the sum of the 16 EPA priority PAHs from the sampled locations from top to bottom had a relative increment in PAHs concentration. summation operatorPAHs ranged from 16.93 ng/g to 68.07 ng/g with a mean concentration of 42.15 ng/g. The correlated results showed the bottom of the large sinkhole, which accounts for the higher concentrations, probably acts like a trap for the PAHs. Thus, the low evaporation rate at the bottom may play a key role in controlling the high concentration of PAHs at the bottom.

  18. Hydrogeochemistry of karst underground waters at shallow depth in Guiyang City, Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    DONG Zhifen; ZHU Lijun; WU Pan; SHEN Zheng; FENG Zhiyong

    2005-01-01

    The aim of this study is to shed light on the hydrogeochemical characteristics of karst underground waters at shallow depth in Guiyang City, Guizhou Province with an emphasis on the geochemistry of major elements. Guiyang City bears abundant underground waters and it is also an important representative of the karst areas throughout the world. Ca 2+ and Mg 2+ are the dominant cations, accounting for 81%- 99.7% of the total, and HCO -3 and SO 2- 4 are the dominant anions. Weathering of limestones and dolostones is the most important factor controlling the hydrogeochemistry of underground waters, and weathering of sulfate and evaporite rocks is less important. Moreover, the precipitation and human activities also have a definite influence on the hydrogeochemistry of underground waters in the region studied.

  19. Community diversity, structure and carbon footprint of nematode food web following reforestation on degraded Karst soil.

    Science.gov (United States)

    Hu, Ning; Li, Hui; Tang, Zheng; Li, Zhongfang; Tian, Jing; Lou, Yilai; Li, Jianwei; Li, Guichun; Hu, Xiaomin

    2016-06-17

    We examined community diversity, structure and carbon footprint of nematode food web along a chronosequence of T. Sinensis reforestation on degraded Karst. In general, after the reforestation: a serious of diversity parameters and community indices (Shannon-Weinier index (H'), structure index (SI), etc.) were elevated; biomass ratio of fungivores to bacterivores (FFC/BFC), and fungi to bacteria (F/B) were increased, and nematode channel ratio (NCR) were decreased; carbon footprints of all nematode trophic groups, and biomass of bacteria and fungi were increased. Our results indicate that the Karst aboveground vegetation restoration was accompanied with belowground nematode food web development: increasing community complexity, function and fungal dominance in decomposition pathway, and the driving forces included the bottom-up effect (resource control), connectedness of functional groups, as well as soil environments.

  20. Karst Aquifer Recharge: A Case History of over Simplification from the Uley South Basin, South Australia

    Directory of Open Access Journals (Sweden)

    Nara Somaratne

    2015-02-01

    Full Text Available The article “Karst aquifer recharge: Comments on ‘Characteristics of Point Recharge in Karst Aquifers’, by Adrian D. Werner, 2014, Water 6, doi:10.3390/w6123727” provides misrepresentation in some parts of Somaratne [1]. The description of Uley South Quaternary Limestone (QL as unconsolidated or poorly consolidated aeolianite sediments with the presence of well-mixed groundwater in Uley South [2] appears unsubstantiated. Examination of 98 lithological descriptions with corresponding drillers’ logs show only two wells containing bands of unconsolidated sediments. In Uley South basin, about 70% of salinity profiles obtained by electrical conductivity (EC logging from monitoring wells show stratification. The central and north central areas of the basin receive leakage from the Tertiary Sand (TS aquifer thereby influencing QL groundwater characteristics, such as chemistry, age and isotope composition. The presence of conduit pathways is evident in salinity profiles taken away from TS water affected areas. Pumping tests derived aquifer parameters show strong heterogeneity, a typical characteristic of karst aquifers. Uley South QL aquifer recharge is derived from three sources; diffuse recharge, point recharge from sinkholes and continuous leakage of TS water. This limits application of recharge estimation methods, such as the conventional chloride mass balance (CMB as the basic premise of the CMB is violated. The conventional CMB is not suitable for accounting chloride mass balance in groundwater systems displaying extreme range of chloride concentrations and complex mixing [3]. Over simplification of karst aquifer systems to suit application of the conventional CMB or 1-D unsaturated modelling as described in Werner [2], is not suitable use of these recharge estimation methods.

  1. Geological constraints on cave development in the plateau-gorge karst of South China (Wulong, Chongqing)

    Science.gov (United States)

    Szczygieł, Jacek; Golicz, Mateusz; Hercman, Helena; Lynch, Erin

    2018-03-01

    The Houping Tiankeng cluster is a part of the South China Karst UNESCO World Natural Heritage Site. Within the distinctive Wulong plateau-gorge karst, > 200 km of cave passages have been documented to date. This paper focuses on detailed tectonic and morphological research on the Luo Shui Kong cave, enriched with U-series dating of speleothems and complemented by morphometric analysis of the San Wang Dong and Er Wang Dong caves. All of these caves exhibit three regional levels of cave development: 1) 1040-1020 m a.s.l.; 2) 900-840 m a.s.l.; and 3) 740-660 m a.s.l. The Houping Tiankeng area is a carbonate rock sequence several hundred meters thick, overlain by the less soluble Lower Ordovician strata, limiting recharge points to faults exposing underlying easily soluble formations. This leads to the domination of concentrated, high-volume inflow and thus results in caves of large volume in the plateau-gorge karst. Shafts connecting the surface with cave passages located underneath formed along faults, changing the hydrogeological pattern through karst water capture and remodeling of existing conduits, albeit mainly by increasing their overall dimensions rather than by deepening them. The most favorable structures for cave-level development are two sets of joints conjugated with gently inclined bedding. Since these joints are characterized by a small vertical extent, downward development is limited. Hence, most of the passages are wide but not deep canyons and typical of a water-table cave pattern. Places where the fault plane is eroded from the surface and where, at the same time, an underneath cave chamber ceiling expands upwards are particularly predisposed to the formation of a tiankeng.

  2. Karst aquifer in Galichica and possibilities for water supply to Ohrid with ground -water

    International Nuclear Information System (INIS)

    Mirchovski, Vojo; Kekich, Aleksandar; Spasovski, Orce; Mirchovski, Vlado

    2009-01-01

    In this paper are presented some hydrogeological features of the karst aquifer in Mt Galichica, which contains important quantities of ground-water that can to used for the water supply of the town Ohrid. Based on the hydrogeological data are given three solutions that be can to used for water supply of Ohrid, the first one is to drill of deep wells, combination of deep and shallow wells, as well as construction of horizontal galleries.

  3. Imaging groundwater infiltration dynamics in the karst vadose zone with long-term ERT monitoring

    Science.gov (United States)

    Watlet, Arnaud; Kaufmann, Olivier; Triantafyllou, Antoine; Poulain, Amaël; Chambers, Jonathan E.; Meldrum, Philip I.; Wilkinson, Paul B.; Hallet, Vincent; Quinif, Yves; Van Ruymbeke, Michel; Van Camp, Michel

    2018-03-01

    Water infiltration and recharge processes in karst systems are complex and difficult to measure with conventional hydrological methods. In particular, temporarily saturated groundwater reservoirs hosted in the vadose zone can play a buffering role in water infiltration. This results from the pronounced porosity and permeability contrasts created by local karstification processes of carbonate rocks. Analyses of time-lapse 2-D geoelectrical imaging over a period of 3 years at the Rochefort Cave Laboratory (RCL) site in south Belgium highlight variable hydrodynamics in a karst vadose zone. This represents the first long-term and permanently installed electrical resistivity tomography (ERT) monitoring in a karst landscape. The collected data were compared to conventional hydrological measurements (drip discharge monitoring, soil moisture and water conductivity data sets) and a detailed structural analysis of the local geological structures providing a thorough understanding of the groundwater infiltration. Seasonal changes affect all the imaged areas leading to increases in resistivity in spring and summer attributed to enhanced evapotranspiration, whereas winter is characterised by a general decrease in resistivity associated with a groundwater recharge of the vadose zone. Three types of hydrological dynamics, corresponding to areas with distinct lithological and structural features, could be identified via changes in resistivity: (D1) upper conductive layers, associated with clay-rich soil and epikarst, showing the highest variability related to weather conditions; (D2) deeper and more resistive limestone areas, characterised by variable degrees of porosity and clay contents, hence showing more diffuse seasonal variations; and (D3) a conductive fractured zone associated with damped seasonal dynamics, while showing a great variability similar to that of the upper layers in response to rainfall events. This study provides detailed images of the sources of drip

  4. River Intrusion in Karst Springs in Eogenetic Aquifers: Implications for Speleogenesis

    Science.gov (United States)

    Martin, J. B.; Gulley, J.; Screaton, E. J.

    2008-12-01

    Conceptual models of speleogenesis generally assume uni-directional transport in integrated conduit systems from discrete recharge points to discharge at karst springs. Estavelles, however, are karst springs that function intermittently as discrete recharge points when river stage rises more rapidly than local aquifer heads. As river water chemistry changes between baseflow and floods, estavelles should influence mass transport through (e.g. organic carbon, nutrients, and oxygen) and speleogenesis within karst systems. Estavelles are common in our study area in north-central Florida, particularly along the lower reaches of the Santa Fe River, where it flows across the unconfined karstic Floridan aquifer. River stage in this unconfined region can rise much faster than aquifer heads when large amounts of rain fall on the confined regions in its upper reaches. Backflooding into the estavelles during elevated river stage drives river water into the ground, causing some springs to reverse and other springs to recirculate large volumes of river water. Floodwaters originating in the confined region are highly undersaturated with respect to calcite, and thus river water transitions from slightly supersaturated to highly undersaturated with respect to calcite during flood events. As a result, conduits connected to estavelles are continuously enlarged as springs reverse or recirculate calcite-undersaturated river water. It has been suggested that currently flooded caves (i.e. karst conduits) associated with springs in Florida formed entirely underwater because speleothems, which are prevalent in flooded caves in the Yucatan and Bahamas, have not been observed by cave divers. Results of this study indicate that the absence of speleothems does not necessarily provide evidence of a continuous phreatic history for underwater caves. Instead speleothems that formed in caves while dry could have been dissolved by backflooding of estavelles with undersaturated water

  5. Evaluating susceptibility of karst dolines (sinkholes) for collapse in Sango, Tennessee, USA

    Science.gov (United States)

    Siska, Peter P.; Goovaerts, Pierre; Hung, I-K

    2016-01-01

    Dolines or sinkholes are earth depressions that develop in soluble rocks complexes such as limestone, dolomite, gypsum, anhydrite, and halite; dolines appear in a variety of shapes from nearly circular to complex structures with highly curved perimeters. The occurrence of dolines in the studied karst area is not random; they are the results of geomorphic, hydrologic, and chemical processes that have caused partial subsidence, even the total collapse of the land surface when voids and caves are present in the bedrock and the regolith arch overbridging these voids is unstable. In the study area, the majority of collapses occur in the regolith (bedrock cover) that bridges voids in the bedrock. Because these collapsing dolines may result in property damage and even cause the loss of lives, there is a need to develop methods for evaluating karst hazards. These methods can then be used by planners and practitioners for urban and economic development, especially in regions with a growing population. The purpose of this project is threefold: 1) to develop a karst feature database, 2) to investigate critical indicators associated with doline collapse, and 3) to develop a doline susceptibility model for potential doline collapse based on external morphometric data. The study has revealed the presence of short range spatial dependence in the distribution of the dolines’ morphometric parameters such as circularity, the geographic orientation of the main doline axes, and the length-to-width doline ratios; therefore, geostatistics can be used to spatially evaluate the susceptibility of the karst area for doline collapse. The partial susceptibility estimates were combined into a final probability map enabling the identification of areas where, until now, undetected dolines may cause significant hazards. PMID:27616807

  6. Imaging groundwater infiltration dynamics in the karst vadose zone with long-term ERT monitoring

    Directory of Open Access Journals (Sweden)

    A. Watlet

    2018-03-01

    Full Text Available Water infiltration and recharge processes in karst systems are complex and difficult to measure with conventional hydrological methods. In particular, temporarily saturated groundwater reservoirs hosted in the vadose zone can play a buffering role in water infiltration. This results from the pronounced porosity and permeability contrasts created by local karstification processes of carbonate rocks. Analyses of time-lapse 2-D geoelectrical imaging over a period of 3 years at the Rochefort Cave Laboratory (RCL site in south Belgium highlight variable hydrodynamics in a karst vadose zone. This represents the first long-term and permanently installed electrical resistivity tomography (ERT monitoring in a karst landscape. The collected data were compared to conventional hydrological measurements (drip discharge monitoring, soil moisture and water conductivity data sets and a detailed structural analysis of the local geological structures providing a thorough understanding of the groundwater infiltration. Seasonal changes affect all the imaged areas leading to increases in resistivity in spring and summer attributed to enhanced evapotranspiration, whereas winter is characterised by a general decrease in resistivity associated with a groundwater recharge of the vadose zone. Three types of hydrological dynamics, corresponding to areas with distinct lithological and structural features, could be identified via changes in resistivity: (D1 upper conductive layers, associated with clay-rich soil and epikarst, showing the highest variability related to weather conditions; (D2 deeper and more resistive limestone areas, characterised by variable degrees of porosity and clay contents, hence showing more diffuse seasonal variations; and (D3 a conductive fractured zone associated with damped seasonal dynamics, while showing a great variability similar to that of the upper layers in response to rainfall events. This study provides detailed images of

  7. Spatial heterogeneities and variability of karst hydro-system : insights from geophysics

    Science.gov (United States)

    Champollion, C.; Fores, B.; Lesparre, N.; Frederic, N.

    2017-12-01

    Heterogeneous systems such as karsts or fractured hydro-systems are challenging for both scientist and groundwater resources management. Karsts heterogeneities prevent the comparison and moreover the combination of data representative of different scales: borehole water level can generally not be used directly to interpret spring flow dynamic for example. The spatial heterogeneity has also an impact on the temporal variability of groundwater transfer and storage. Karst hydro-systems have characteristic non linear relation between precipitation amount and discharge at the outlets with threshold effects and a large variability of groundwater transit times In the presentation, geophysical field experiments conducted in karst hydro-system in the south of France are used to investigate groundwater transfer and storage variability at a scale of a few hundred meters. We focus on the added value of both geophysical time-lapse gravity experiments and 2D ERT imaging of the subsurface heterogeneities. Both gravity and ERT results can only be interpreted with large ambiguity or some strong a priori: the relation between resistivity and water content is not unique; almost no information about the processes can be inferred from the groundwater stock variations. The present study demonstrate how the ERT and gravity field experiments can be interpreted together in a coherent scheme with less ambiguity. First the geological and hydro-meteorological context is presented. Then the ERT field experiment including the processing and the results are detailed in the section about geophysical imaging of the heterogeneities. The gravity double difference (S2D) time-lapse experiment is described in the section about geophysical monitoring of the temporal variability. The following discussion demonstrate the impact of both experiments on the interpretation in terms of processes and heterogeneities.

  8. Enhanced nitrogen availability in karst ecosystems by oxalic acid release in the rhizosphere

    Directory of Open Access Journals (Sweden)

    Fujing ePan

    2016-05-01

    Full Text Available In karst ecosystems, a high level of CaCO3 enhances the stabilization of soil organic matter (SOM and causes nitrogen (N and/or phosphorus (P limitation in plants. Oxalic acid has been suggested to be involved in the nutrient-acquisition strategy of plants because its addition can temporarily relieve nutrient limitation. Therefore, understanding how oxalic acid drives N availability may help support successful vegetation restoration in the karst ecosystems of southwest China. We tested a model suggested by Clarholm et al. (2015 where oxalate reacts with Ca bridges in SOM, thus exposing previously protected areas to enzymatic attacks in a way that releases N for local uptake. We studied the effects of oxalic acid, microbial biomass C (MBC, and β-1,4-N-acetylglucosaminidase (NAG on potential N mineralization rates in rhizosphere soils of four plant species (two shrubs and two trees in karst areas. The results showed that rhizosphere soils of shrubs grown on formerly deforested land had significantly lower oxalic acid concentrations and NAG activity than that of trees in a 200-year-old forest. The levels of MBC in rhizosphere soils of shrubs were significantly lower than those of trees in the growing season, but the measure of shrubs and trees were similar in the non-growing season; the potential N mineralization rates showed a reverse pattern. Positive relationships were found among oxalic acid, MBC, NAG activity, and potential N mineralization rates for both shrubs and trees. This indicated that oxalic acid, microbes, and NAG may enhance N availability for acquisition by plants. Path analysis showed that oxalic acid enhanced potential N mineralization rates indirectly through inducing microbes and NAG activities. We found that the exudation of oxalic acid clearly provides an important mechanism that allows plants to enhance nutrient acquisition in karst ecosystems.

  9. The mammalian fauna of Barová Cave (Moravian Karst, the Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Roblíčková, M.; Káňa, V.; Nývltová Fišáková, Miriam

    2017-01-01

    Roč. 73, 3-4 (2017), s. 515-532 ISSN 2533-4050 Institutional support: RVO:68081758 Keywords : Quaternary palaeontology * Late Pleistocene * Moravian Karst * Barová Cave * animal assemblage * Ursus ex gr. spelaeus * wintering site * gnawing marks * hunting and scavenging * seasonality * dental age Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Paleontology http://fi.nm.cz/wp-content/uploads/2017/12/15_Roblickova_et-al_2017.pdf

  10. Hydrological deformation signals in karst systems: new evidence from the European Alps

    Science.gov (United States)

    Serpelloni, E.; Pintori, F.; Gualandi, A.; Scoccimarro, E.; Cavaliere, A.; Anderlini, L.; Belardinelli, M. E.; Todesco, M.

    2017-12-01

    The influence of rainfall on crustal deformation has been described at local scales, using tilt and strain meters, in several tectonic settings. However, the literature on the spatial extent of rainfall-induced deformation is still scarce. We analyzed 10 years of displacement time-series from 150 continuous GPS stations operating across the broad zone of deformation accommodating the N-S Adria-Eurasia convergence and the E-ward escape of the Eastern Alps toward the Pannonian basin. We applied a blind-source-separation algorithm based on a variational Bayesian Independent Component Analysis method to the de-trended time-series, being able to characterize the temporal and spatial features of several deformation signals. The most important ones are a common mode annual signal, with spatially uniform response in the vertical and horizontal components and a time-variable, non-cyclic, signal characterized by a spatially variable response in the horizontal components, with stations moving (up to 8 mm) in the opposite directions, reversing the sense of movement in time. This implies a succession of extensional/compressional strains, with variable amplitudes through time, oriented normal to rock fractures in karst areas. While seasonal displacements in the vertical component (with an average amplitude of 4 mm over the study area) are satisfactorily reproduced by surface hydrological loading, estimated from global assimilation models, the non seasonal signal is associated with groundwater flow in karst systems, and is mainly influencing the horizontal component. The temporal evolution of this deformation signal is correlated with cumulated precipitation values over periods of 200-300 days. This horizontal deformation can be explained by pressure changes associated with variable water levels within vertical fractures in the vadose zones of karst systems, and the water level changes required to open or close these fractures are consistent with the fluctuations of precipitation

  11. SWAT Model Prediction of Phosphorus Loading in a South Carolina Karst Watershed with a Downstream Embayment

    Science.gov (United States)

    Devendra M. Amatya; Manoj K. Jha; Thomas M. Williams; Amy E. Edwards; Daniel R.. Hitchcock

    2013-01-01

    The SWAT model was used to predict total phosphorus (TP) loadings for a 1555-ha karst watershed—Chapel Branch Creek (CBC)—which drains to a lake via a reservoir-like embayment (R-E). The model was first tested for monthly streamflow predictions from tributaries draining three potential source areas as well as the downstream R-E, followed by TP loadings using data...

  12. Climate change and Mediterranean coastal karst aquifers: the case of Salento (southern Italy)

    OpenAIRE

    Polemio, M.; Romanazzi, A.

    2014-01-01

    Second half of the 20th century was characterized by an increase of groundwater discharge. Numerous aquifers are overexploited in the world and in particular in the Mediterranean area. Problems tie to overexploitation, as piezometric decline and increase of seawater intrusion, are amplified in karst coastal aquifers where the whole effect could be a groundwater quality and quantity degradation. Focusing on Mediterranean countries, most part of coastal aquifers of Spain, France, Portugal, S...

  13. Nitrogen isotope compositions and spatial distribution characteristics of soil in the process of karst rocky desertification

    International Nuclear Information System (INIS)

    Luo Xuqiang; Wang Shijie; Wang Chengyuan; Liang Yuhua; Liao Xinrong; Yang Hongyan

    2011-01-01

    Isotopic composition and spatial distribution characteristic of total nitrogen of the surficial soil in karst rocky desertification area, including different types, different grades and different disturbed modes karst rocky desertification within the same small catchment, which belong to the Wangjiazhai peak-cluster depression basin and located in Qingzhen City, Guizhou Province were discussed in this study. Results showed that δ 15 N values of total nitrogen in top soil in yellow soil area were mainly between +0.35‰ ∼ +6.82% with the average of +4.50‰, and between +2.70‰ ∼ +6.50‰ in black calcareous with the average of +4.27‰. In both yellow soil area and black calcareous area, there were no significant difference in the δ 15 N values of total nitrogen on sample lands of rocky desertification at different levels, different ways of interruption and different slope positions, and no obvious difference on the whole (P≤0.05), which is mainly due to the high habitat heterogeneity of karst area. (authors)

  14. Monthly sediment discharge changes and estimates in a typical karst catchment of southwest China

    Science.gov (United States)

    Li, Zhenwei; Xu, Xianli; Xu, Chaohao; Liu, Meixian; Wang, Kelin; Yi, Ruzhou

    2017-12-01

    As one of the largest karst regions in the world, southwest China is experiencing severe soil erosion due to its special geological conditions, inappropriate land use, and lower soil loss tolerance. Knowledge and accurate estimations of changes in sediment discharge rates is important for finding potential measures to effectively control sediment delivery. This study investigated temporal variation in monthly sediment discharge (SD), and developed sediment rating curves and state-space model to estimate SD. Monthly water discharge, SD, precipitation, potential evapotranspiration, and normalized differential vegetation index during 2003-2015 collected from a typical karst catchment of Yujiang River were analyzed in present study. A Mann-Kendal test and Morlet wavelet analysis were employed to detect the changes in SD. Results indicated that a decreasing trend was observed in sediment discharge at monthly and annual scale. The water and sediment discharge both had a significant 1-year period, implying that water discharge has substantial influence on SD. The best state-space model using water discharge was a simple but effective model, accounting for 99% of the variation in SD. The sediment rating curves, however, represented only 78% of the variation in SD. This study provides an insight into the possibility of accurate estimation of SD only using water discharge with state-space model approach. State-space model is recommended as an effective approach for quantifying the temporal relationships between SD and its driving factors in karst regions of southwest China.

  15. The Study of Abundance of Soil Minerals on Micro Toposequen of Karst Gunungsewu Pegunungan Selatan

    Directory of Open Access Journals (Sweden)

    Djoko Mulyanto

    2008-05-01

    Full Text Available Landform of Gunungsewu karst topography dominated by positive forms consists of hills and negative forms of dolines. On the micro toposequen of karst, most of dolines dominated by red soils which hue 2.5 YR – 5 YR, whereas on hills by soils which hue 5 YR – 7.5 YR. The aim of research was to study of soil minerals status on karst micro toposequent. Results showed that soil minerals of sand fraction on dolines dominated by quartz, opaque, and iron concretion, whereas on hills dominated by labradorite, and mafic minerals. Clay minerals on doline dominated by kaolinite whereas on hills by halloysite. The high concentration of kaolinite, quartz, opaque and iron concretions of soils on dolines appropriate with degree of soil weathering which in a line with decreasing of soil pH, silt/ clay ratio, and hue of soils on dolines redder than hue of soils on hills. The origin of soil parent material suggested come from volcanic materials.

  16. Hydrological response and thermal effect of karst springs linked to aquifer geometry and recharge processes

    Science.gov (United States)

    Luo, Mingming; Chen, Zhihua; Zhou, Hong; Zhang, Liang; Han, Zhaofeng

    2018-03-01

    To be better understand the hydrological and thermal behavior of karst systems in South China, seasonal variations in flow, hydrochemistry and stable isotope ratios of five karst springs were used to delineate flow paths and recharge processes, and to interpret their thermal response. Isotopic data suggest that mean recharge elevations are 200-820 m above spring outlets. Springs that originate from high elevations have lower NO3 - concentrations than those originating from lower areas that have more agricultural activity. Measured Sr2+ concentrations reflect the strontium contents of the host carbonate aquifer and help delineate the spring catchment's saturated zone. Seasonal variations of NO3 - and Sr2+ concentrations are inversely correlated, because the former correlates with event water and the latter with baseflow. The mean annual water temperatures of springs were only slightly lower than the local mean annual surface temperature at the outlet elevations. These mean spring temperatures suggest a vertical gradient of 6 °C/vertical km, which resembles the adiabatic lapse rate of the Earth's stable atmosphere. Seasonal temperature variations in the springs are in phase with surface air temperatures, except for Heilongquan (HLQ) spring. Event-scale variations of thermal response are dramatically controlled by the circulation depth of karst systems, which determines the effectiveness of heat exchange. HLQ spring undergoes the deepest circulation depth of 820 m, and its thermal responses are determined by the thermally effective regulation processes at higher elevations and the mixing processes associated with thermally ineffective responses at lower elevations.

  17. Characterization of the hydrogeology of the sacred Gihon Spring, Jerusalem: a deteriorating urban karst spring

    Science.gov (United States)

    Amiel, Ronit Benami; Grodek, Tamir; Frumkin, Amos

    2010-09-01

    The Gihon Spring, Jerusalem, is important for the major monotheistic religions. Its hydrogeology and hydrochemistry is studied here in order to understand urbanization effects on karst groundwater resources, and promote better water management. High-resolution monitoring of the spring discharge, temperature and electrical conductivity, was performed, together with chemical and bacterial analysis. All these demonstrate a rapid response of the spring to rainfall events and human impact. A complex karst system is inferred, including conduit flow, fissure flow and diffuse flow. Electrical conductivity, Na+ and K+ values (2.0 mS/cm, 130 and 50 mg/l respectively) are very high compared to other nearby springs located at the town margins (0.6 mS/cm, 15 and <1 mg/l respectively), indicating considerable urban pollution in the Gihon area. The previously cited pulsating nature of the spring was not detected during the present high-resolution monitoring. This phenomenon may have ceased due to additional water sources from urban leakage and irrigation feeding the spring. The urbanization of the recharge catchment thus affects the spring water dramatically, both chemically and hydrologically. Appropriate measures should therefore be undertaken to protect the Gihon Spring and other karst aquifers threatened by rapid urbanization.

  18. Karst water control and management in the Hanxing mining area of North China

    Energy Technology Data Exchange (ETDEWEB)

    Wanfang, Z. [P.E. LaMoreaux and Associates, Inc., Oak Ridge, TN (United States)

    1997-04-01

    The Hanxing mining area of North China includes three coalfields: Fengfeng, Handan and Xingtai. Six or seven coal seams can be commercially mined in Permo-Carboniferous strata, among which the lower three, accounting for 37% of the total reserves, are threatened with karst water from the underlain Ordovician limestone. Hundreds of water inrush accidents have occurred and over 30 mines have been flooded, resulting in heavy economic losses and casualties. In order to avoid water inrushes and keep the mines safely operational, dewatering in the karst aquifer was considered an essential measure. Unfortunately, this practice has caused serious environmental problems such as surface subsidence (sinkhole), dry spring, and water supply shortage. On the basis of a series of investigations and tests in the last 20 years, an alternative method, mining with water pressure, has been proposed and is the main focus of this paper. By using this method, the karst water in the limestone can be preserved to some extent and the coals can be mined in a relatively safe way. (orig.)

  19. Modeling of karst deformation and analysis of acoustic emission during sinkhole formation

    Science.gov (United States)

    Bakeev, R. A.; Stefanov, Yu. P.; Duchkov, A. A.; Myasnikov, A. V.

    2017-12-01

    In this paper, the fracture pattern and formation of a sinkhole are estimated depending on the rock properties. The possibility of using geophysical methods for recording and analyzing acoustic emission to monitor and predict the state of the medium is considered. The problem of deformation of the sedimentary cover over the growing karst cavity is solved on the basis of the elastoplastic Drucker-Prager-Nikolaevsky model and the equation of damage accumulation. The specified kinetics of accumulation of damages allows us to describe slow processes of degradation of the strength of the medium under stresses that are low for the development of inelastic deformations. The results are obtained for different values of the strength of karst rock; we show the influence of the kinetic parameters of damage accumulation on the shape of collapse depressions. We also model acoustic emission caused by the material fracture. One can follow different stages of the karst development by looking at patterns of cells which fail at a given time. Our observations show the relation between the intensity of material fracture and the intensity of seismic emission.

  20. Diversitas Kelelawar (Chiroptera Penghuni Gua, Studi Gua Ngerong di Kawasan Karst Tuban Jawa Timur

    Directory of Open Access Journals (Sweden)

    Tatag Bagus Putra Prakarsa

    2013-12-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui diversitas kelelawar penghuni gua di gua Ngerong. Penelitian ini merupakan penelitian Nature Snapshop Experiment (NSE. Penelitian ini dilaksanakan pada bulan November - Desember 2011 di gua Ngerong, Desa Rengel, Kecamatan Rengel, Kabupaten Tuban, Jawa Timur. Penangkapan dilakukan dengan metode tangkap langsung. Penangkapan dilakukan dengan menggunakan misnet dan handnet. Kelelawar diidentifikasi berdasarkan pengukuran morfometri dan ciri morfologi mengacu kunci identifikasi Suyanto, 2001 dan Payne et al., 2000. Seluruh data dianalisis secara deskriptif. Di gua Ngerong terdapat 9 spesies dari 4 famili atau 60% dari total spesies kelelawar penghuni gua di kawasan karst Tuban. Enam spesies anggota Subordo Microchiroptera yang merupakan insectivor dan 3 spesies anggota Subordo Megachiroptera yang merupakan frugivor dan nictivor. Keanekaragaman di gua Ngerong tergolong tinggi dengan nilai Simpson's Diversity Index sebesar 0,76. Tingginya diversitas kelelawar penghuni gua Ngerong berbanding lurus dengan panjang lorong gua Ngerong. gua Ngerong merupakan gua terpanjang di kawasan karst Tuban, dengan panjang lorong mencapai 1800m.kata kunci: Kelelawar (Chiroptera, Diversitas, Gua Ngerong, Biospeleologi, Karst

  1. Projected land use changes impacts on water yields in the karst mountain areas of China

    Science.gov (United States)

    Lang, Yanqing; Song, Wei; Deng, Xiangzheng

    2018-04-01

    Human-induced land use changes over short time scales have significant impacts on water yield, especially in China because of the rapid social economic development. As the biggest developing country of the world, China's economy is expected to continuously grow with a high speed in the next few decades. Therefore, what kind of land use changes will occur in the future in China? How these changes will influence the water yields? To address this issue, we assessed the water yields in the karst mountain area of China during the periods of 1990-2010 and 2010-2030 by coupling an Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and a Conversion of Land Use and its Effects (CLUE) model. Three different land use scenarios i.e. natural growth, economic development, and ecological protection, were developed in 2030 using the CLUE model. It was concluded that, given land use changes between 1990 and 2010, total water yields in the karst mountain area are characterized by a trend towards fluctuating reduction. However, total water yields of 2030 in the economic development scenario revealed an increase of 1.25% compared to the actual water yields in 2010. The economy development in karst mountain areas of China in the future has a slight positive influence on water yields.

  2. Concepts of karst development in relation to interpretation of surface runoff

    Science.gov (United States)

    LeGrand, H.E.; Stringfield, V.T.

    1973-01-01

    Some unusual characteristics of streamflow occur in regions underlain by carbonate rocks. The streamflow characteristics are related to processes of karstification, these processes being dependent on circulation of subsurface water and solution of the rock to form characteristic topography and underground cavern systems.  Very highly cavernous and permeable unsaturated zones tend to keep the water table depressed below land surface in many karst regions, a condition that leads to a low density of perennial streams. The uneven distribution of permeability beneath surface karst streams causes them to lose or gain water, depending on the position of the water table with reference to stream level. The conventional techniques of interpolation and extrapolation that have been reasonably successful in approximating streamflow of ungaged sites in nonkarstic regions have only limited use in karst regions. An understanding of principles of karstification and an understanding of the hydrogeologic framework of a carbonate terrane provide a useful basis for evaluating the streamflow characteristics.

  3. Hydrogeological controls of variable microbial water quality in a complex subtropical karst system in Northern Vietnam

    Science.gov (United States)

    Ender, Anna; Goeppert, Nadine; Goldscheider, Nico

    2018-05-01

    Karst aquifers are particularly vulnerable to bacterial contamination. Especially in developing countries, poor microbial water quality poses a threat to human health. In order to develop effective groundwater protection strategies, a profound understanding of the hydrogeological setting is crucial. The goal of this study was to elucidate the relationships between high spatio-temporal variability in microbial contamination and the hydrogeological conditions. Based on extensive field studies, including mapping, tracer tests and hydrochemical analyses, a conceptual hydrogeological model was developed for a remote and geologically complex karst area in Northern Vietnam called Dong Van. Four different physicochemical water types were identified; the most important ones correspond to the karstified Bac Son and the fractured Na Quan aquifer. Alongside comprehensive investigation of the local hydrogeology, water quality was evaluated by analysis for three types of fecal indicator bacteria (FIB): Escherichia coli, enterococci and thermotolerant coliforms. The major findings are: (1) Springs from the Bac Son formation displayed the highest microbial contamination, while (2) springs that are involved in a polje series with connections to sinking streams were distinctly more contaminated than springs with a catchment area characterized by a more diffuse infiltration. (3) FIB concentrations are dependent on the season, with higher values under wet season conditions. Furthermore, (4) the type of spring capture also affects the water quality. Nevertheless, all studied springs were faecally impacted, along with several shallow wells within the confined karst aquifer. Based on these findings, effective protection strategies can be developed to improve groundwater quality.

  4. Caffeine as an indicator for the quantification of untreated wastewater in karst systems.

    Science.gov (United States)

    Hillebrand, Olav; Nödler, Karsten; Licha, Tobias; Sauter, Martin; Geyer, Tobias

    2012-02-01

    Contamination from untreated wastewater leakage and related bacterial contamination poses a threat to drinking water quality. However, a quantification of the magnitude of leakage is difficult. The objective of this work is to provide a highly sensitive methodology for the estimation of the mass of untreated wastewater entering karst aquifers with rapid recharge. For this purpose a balance approach is adapted. It is based on the mass flow of caffeine in spring water, the load of caffeine in untreated wastewater and the daily water consumption per person in a spring catchment area. Caffeine is a source-specific indicator for wastewater, consumed and discharged in quantities allowing detection in a karst spring. The methodology was applied to estimate the amount of leaking and infiltrating wastewater to a well investigated karst aquifer on a daily basis. The calculated mean volume of untreated wastewater entering the aquifer was found to be 2.2 ± 0.5 m(3) d(-1) (undiluted wastewater). It corresponds to approximately 0.4% of the total amount of wastewater within the spring catchment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Points of Interest: What Determines Interest Rates?

    Science.gov (United States)

    Schilling, Tim

    Interest rates can significantly influence people's behavior. When rates decline, homeowners rush to buy new homes and refinance old mortgages; automobile buyers scramble to buy new cars; the stock market soars, and people tend to feel more optimistic about the future. But even though individuals respond to changes in rates, they may not fully…

  6. Numerical modeling and sensitivity analysis of seawater intrusion in a dual-permeability coastal karst aquifer with conduit networks

    Directory of Open Access Journals (Sweden)

    Z. Xu

    2018-01-01

    Full Text Available Long-distance seawater intrusion has been widely observed through the subsurface conduit system in coastal karst aquifers as a source of groundwater contaminant. In this study, seawater intrusion in a dual-permeability karst aquifer with conduit networks is studied by the two-dimensional density-dependent flow and transport SEAWAT model. Local and global sensitivity analyses are used to evaluate the impacts of boundary conditions and hydrological characteristics on modeling seawater intrusion in a karst aquifer, including hydraulic conductivity, effective porosity, specific storage, and dispersivity of the conduit network and of the porous medium. The local sensitivity analysis evaluates the parameters' sensitivities for modeling seawater intrusion, specifically in the Woodville Karst Plain (WKP. A more comprehensive interpretation of parameter sensitivities, including the nonlinear relationship between simulations and parameters, and/or parameter interactions, is addressed in the global sensitivity analysis. The conduit parameters and boundary conditions are important to the simulations in the porous medium because of the dynamical exchanges between the two systems. The sensitivity study indicates that salinity and head simulations in the karst features, such as the conduit system and submarine springs, are critical for understanding seawater intrusion in a coastal karst aquifer. The evaluation of hydraulic conductivity sensitivity in the continuum SEAWAT model may be biased since the conduit flow velocity is not accurately calculated by Darcy's equation as a function of head difference and hydraulic conductivity. In addition, dispersivity is no longer an important parameter in an advection-dominated karst aquifer with a conduit system, compared to the sensitivity results in a porous medium aquifer. In the end, the extents of seawater intrusion are quantitatively evaluated and measured under different scenarios with the variabilities of

  7. Geophysical Surveys of a Known Karst Feature, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Doll, W.E.; Nyquist, J.E.; Carpenter, P.J.; Kaufmann, R.D.; Carr, B.J.

    1998-01-01

    Geophysical data were acquired at a site on the Oak Ridge Reservation, Tennessee to determine the characteristics of a mud-filled void and to evaluate the effectiveness of a suite of geophysical methods at the site. Methods that were used included microgravity, electrical resistivity, and seismic refraction. Both microgravity and resistivity were able to detect the void as well as overlying structural features. The seismic data provide bedrock depth control for the other two methods, and show other effects that are caused by the void

  8. Interest Rate Swaps

    OpenAIRE

    Marina Pepic

    2014-01-01

    Interest rates changes have a huge impact on the business performance. Therefore, it is of great importance for the market participants to identify and adequately manage this risk. Financial derivatives are a relatively simple way of protection from adverse changes in interest rates. Interest rate swaps are particularly popular because they reduce interest rate risk to a minimum with a relatively low initial cost and without great risk, but also because of the fact that there are many modific...

  9. Understanding Interest Rate Volatility

    OpenAIRE

    Volker, Desi

    2016-01-01

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochast...

  10. Advanced data processing of airborne electromagnetic data for imaging hidden conduit networks in the coastal karst plain of Tulum (Mexico)

    International Nuclear Information System (INIS)

    Schiller, A.; Schattauer, I.; Ottowitz, D.

    2016-01-01

    This study is part of a series of international research cooperations which commenced in 2007 and are still ongoing. The study area is located on the east coast of the Yucatan Peninsula, Mexico, and comprises the northern most part of the Sian Kaan biosphere reserve, a coastal wetland of international importance, as well as the city of Tulum in the state of Quintana Roo, and part of the second largest barrier reef in the world some 300 metres to one kilometre off shore. Two airborne surveys, conducted in 2007 and 2008 by the Geological Survey of Austria, covered an area of some 200 square kilometres, including the well-known Ox Bel Ha cave system, already mapped by exploration divers. In order to get additional ground truth data and input for the hydrological model, extended ground geophysical campaigns have been conducted an - nually. The first processing of the airborne electromagnetic (AEM) data revealed not only a clear signature from known caves but also the image of a vast, unexplored, hidden conduit network. However, lateral and depth resolution was limited due to measurement drift and noise as well the specific behaviour of the ap - plied inversion technique. Newly developed algorithms for processing AEM data and inversion results have improved the signal-to-noise ratio significantly and enabled the imaging of well defined structures in the underground. Therefore, the AEM method is now capable of quickly deliver crucial structural information of karst-water regimes in difficult accessible areas with unique depth information compared to previous studies. (Author)

  11. Factors affecting ground-water exchange and catchment size for Florida lakes in mantled karst terrain

    Science.gov (United States)

    Lee, Terrie Mackin

    2002-01-01

    In the mantled karst terrain of Florida, the size of the catchment delivering ground-water inflow to lakes is often considerably smaller than the topographically defined drainage basin. The size is determined by a balance of factors that act individually to enhance or diminish the hydraulic connection between the lake and the adjacent surficial aquifer, as well as the hydraulic connection between the surficial aquifer and the deeper limestone aquifer. Factors affecting ground-water exchange and the size of the ground-water catchment for lakes in mantled karst terrain were examined by: (1) reviewing the physical and hydrogeological characteristics of 14 Florida lake basins with available ground-water inflow estimates, and (2) simulating ground-water flow in hypothetical lake basins. Variably-saturated flow modeling was used to simulate a range of physical and hydrogeologic factors observed at the 14 lake basins. These factors included: recharge rate to the surficial aquifer, thickness of the unsaturated zone, size of the topographically defined basin, depth of the lake, thickness of the surficial aquifer, hydraulic conductivity of the geologic units, the location and size of karst subsidence features beneath and onshore of the lake, and the head in the Upper Floridan aquifer. Catchment size and the magnitude of ground-water inflow increased with increases in recharge rate to the surficial aquifer, the size of the topographically defined basin, hydraulic conductivity in the surficial aquifer, the degree of confinement of the deeper Upper Floridan aquifer, and the head in the Upper Floridan aquifer. The catchment size and magnitude of ground-water inflow increased with decreases in the number and size of karst subsidence features in the basin, and the thickness of the unsaturated zone near the lake. Model results, although qualitative, provided insights into: (1) the types of lake basins in mantled karst terrain that have the potential to generate small and large

  12. Carbon gains by conservation projects overbalance carbon losses by degradation in China's karst ecoregions

    Science.gov (United States)

    Tong, X.; Yue, Y.; Fensholt, R.; Brandt, M.

    2017-12-01

    China's ecological restoration projects are considered as "mega-engineering" activities and the most ambitious afforestation and conservation projects in human history. The highly sensitive and vulnerable karst ecosystem in Southwest China is one of the largest exposed carbonate rock areas (more than 0.54 million km2) in the world. Accelerating desertification has been reported during the last half century, caused by the increasing intensity of human exploitation of natural resources. As a result, vast karst areas (approximately 0.12 million km2) previously covered by vegetation and soil were turned into a rocky landscape. To combat this severe form of land degradation, more than 19 billion USD have been invested in mitigation initiatives since the end of the 1990s. The costs of mega-engineering as a climate change mitigation measure are however only justified if ecosystem properties can be affected at large scales. Here we study the carbon balance of the karst regions of 8 Chinese provinces over four decades, using optical and passive microwave satellite data, supported by statistical data on project implementations. We find that most areas experiencing losses in aboveground biomass carbon are located in areas with a high standing biomass ( 95 Mg C ha-1), whereas areas with a carbon gain are mostly located in regions with a low standing biomass ( 45 Mg C ha-1). However, the overall gains in carbon stocks overbalance the losses, with an average gross loss of -0.8 Pg C and a gross gain of +2.4 Pg C (1980s to 2016), resulting in a net gain of 1.6 Pg C. Areas of carbon gains are widespread and spatially coherent with conservation projects implemented after 2001, whereas areas of carbon losses show that ongoing degradation is still happening in the western parts of the karst regions. We conclude that the impact of conservation projects on the carbon balance of China's karst ecoregions is remarkable, but biomass carbon losses caused by ongoing degradation can not be

  13. Understanding Interest Rate Volatility

    DEFF Research Database (Denmark)

    Volker, Desi

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty...... and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochastic Volatility" (co-authored with Sebastian Fux), investigates the ability of the class of regime switching models...... with and without stochastic volatility to capture the main stylized features of U.S. interest rates. The third essay, \\Variance Risk Premia in the Interest Rate Swap Market", investigates the time-series and cross-sectional properties of the compensation demanded for holding interest rate variance risk. The essays...

  14. A multi-method approach for groundwater resource assessment in coastal carbonate (karst) aquifers: the case study of Sierra Almijara (southern Spain)

    Science.gov (United States)

    Andreo, B.; Barberá, J. A.; Mudarra, M.; Marín, A. I.; García-Orellana, J.; Rodellas, V.; Pérez, I.

    2018-02-01

    Understanding the transference of water resources within hydrogeological systems, particularly in coastal aquifers, in which groundwater discharge may occur through multiple pathways (through springs, into rivers and streams, towards the sea, etc.), is crucial for sustainable groundwater use. This research aims to demonstrate the usefulness of the application of conventional recharge assessment methods coupled to isotopic techniques for accurately quantifying the hydrogeological balance and submarine groundwater discharge (SGD) from coastal carbonate aquifers. Sierra Almijara (Southern Spain), a carbonate aquifer formed of Triassic marbles, is considered as representative of Mediterranean coastal karst formations. The use of a multi-method approach has permitted the computation of a wide range of groundwater infiltration rates (17-60%) by means of direct application of hydrometeorological methods (Thornthwaite and Kessler) and spatially distributed information (modified APLIS method). A spatially weighted recharge rate of 42% results from the most coherent information on physiographic and hydrogeological characteristics of the studied system. Natural aquifer discharge and groundwater abstraction have been volumetrically quantified, based on flow and water-level data, while the relevance of SGD was estimated from the spatial analysis of salinity, 222Rn and the short-lived radium isotope 224Ra in coastal seawater. The total mean aquifer discharge (44.9-45.9 hm3 year-1) is in agreement with the average recharged groundwater (44.7 hm3 year-1), given that the system is volumetrically equilibrated during the study period. Besides the groundwater resources assessment, the methodological aspects of this research may be interesting for groundwater management and protection strategies in coastal areas, particularly karst environments.

  15. [Characteristics of foliar delta13C values of common shrub species in various microhabitats with different karst rocky desertification degrees].

    Science.gov (United States)

    Du, Xue-Lian; Wang, Shi-Jie; Rong, Li

    2011-12-01

    By measuring the foliar delta13C values of 5 common shrub species (Rhamnus davurica, Pyracantha fortuneana, Rubus biflorus, Zanthoxylum planispinum, and Viburnum utile) growing in various microhabitats in Wangjiazhai catchment, a typical karst desertification area in Guizhou Province, this paper studied the spatial heterogeneity of plant water use at niche scale and the response of the heterogeneity to different karst rocky desertification degrees. The foliar delta13C values of the shrub species in the microhabitats followed the order of stony surface > stony gully > stony crevice > soil surface, and those of the majority of the species were more negative in the microhabitat soil surface than in the others. The foliar delta13C values decreased in the sequence of V. utile > R. biflorus > Z. planispinum > P. fortuneana > R. davurica, and the mean foliar delta13C value of the shrubs and that of typical species in various microhabitats all increased with increasing karst rocky desertification degree, differed significantly among different microhabitats. It was suggested that with the increasing degree of karst rocky desertification, the structure and functions of karst habitats were impaired, microhabitats differentiated gradually, and drought degree increased.

  16. Using streamflow and hydrochemical tracers to conceptualise hydrological function of underground channel system in a karst catchment of southwest China

    Science.gov (United States)

    Zhang, Zhicai; Chen, Xi; Wang, Jinli

    2016-04-01

    Karst hydrodynamic behaviour is complex because of special karst geology and geomorphology. The permeable multi-media consisting of soil, epikarst fractures and conduits has a key influence on karst hydrological processes. Spatial heterogeneity is high due to special landforms of vertical shafts, caves and sinkholes, which leads to a high dynamic variability of hydrological processes in space and time, and frequent exchange of surface water and groundwater. Underground water in different reach were sampled over the 1996-2001 in a karst catchment of Houzhai, with 81km2, located in Guizhou province of southwest China. Samples were analysed for water temperature, pH, conductivity and four solute concentrations. The monitoring sought to assess the combined utility of flow discharge and natural geochemical tracers in upscaling flow structure understanding in karst area. Based on previous researches and field investigation, the catchment characteristics were explored with the use of a GIS. Both flow discharge and solute concentrations exhibited clear seasonal patterns at every groundwater sampling sites. The variations of flow and chemistry are more dramatic in upstream site with less soil cover and more sinkholes development, which affect the hydrological pathways significantly. There was clear evidence that the differences in geology and soil were the main controls on hydrology and flow chemistry, which was spatially variable in different sites of underground channel. Conceptual flow structures in main hydrological response units for different area in the catchment were developed according to the variation of discharge and flow chemistry.

  17. First definitive record of a stygobiotic fish (Percopsiformes, Amblyopsidae, Typhlichthys from the Appalachians karst region in the eastern United States

    Directory of Open Access Journals (Sweden)

    Matthew L. Niemiller

    2016-11-01

    Full Text Available In the central and eastern United States, cavefishes have been known historically only from the Interior Low Plateau and Ozarks karst regions. Previously, cavefishes were unknown from the Appalachians karst region, which extends from southeastern New York southwestward into eastern Tennessee, northwestern Georgia, and northeastern Alabama. Here we report the discovery of a new population of the amblyopsid cavefish Typhlichthys subterraneus Girard, 1859 from a cave in Catoosa County, Georgia, that significantly extends the known distribution of the species. The cave is located in the Appalachian Valley and Ridge physiographic province and Appalachians karst region, and represents the first definitive report of a stygobiotic fish from the Appalachians karst region. Genetic analyses of one mitochondrial and one nuclear locus from the cavefish indicate this population is closely allied with populations that occur along the western margins of Lookout and Fox mountains in Dade County, Georgia, and populations to the northwest in southern Marion County, Tennessee. It is likely that these populations are also related to those from Wills Valley, DeKalb County, Alabama. The distribution of this new population of T. subterraneus and its close allies pre-dates the emergence of a Tennessee-Coosa River drainage divide in the Pliocene. The potential exists to discover additional populations in caves within the Appalachians karst region in Catoosa County and northward into Hamilton County, Tennessee.

  18. [People's interest in health information].

    Science.gov (United States)

    Horch, K; Wirz, J

    2005-11-01

    Well-informed citizens and patients regard health policy innovations as a key element when it comes to reforms in the health service--both in health economics and with regard to prevention issues. We evaluated the data provided by the 2003 Telephone Health Survey (GSTel03) to examine demographic and social distinctions in the use of different information sources. At the same time we examined whether there are any population-related differences in people's interest in health information depending on their levels of health awareness, attitudes to prevention and related modes of behaviour. The data generated by the survey show that there is considerable interest in health-related topics. Only 2% of the people questioned used no information sources for this purpose. In addition to more traditional media (books, newspapers, information from pharmacies), information provided by health insurance companies and via the Internet is becoming increasingly important. With the exception of the Internet, all other sources of information are used more frequently by women than by men, and demand for most of the information media increases with age. The frequency of information use and the number of different media used increase from the lower to the upper strata of society. As far as selected variables of health-related behaviour are concerned (smoking, sport, alcohol), the results show a link between a more positive attitude to health and a greater interest in information.

  19. Interest Rates and Inflation

    OpenAIRE

    Coopersmith, Michael; Gambardella, Pascal J.

    2016-01-01

    This article is an extension of the work of one of us (Coopersmith, 2011) in deriving the relationship between certain interest rates and the inflation rate of a two component economic system. We use the well-known Fisher relation between the difference of the nominal interest rate and its inflation adjusted value to eliminate the inflation rate and obtain a delay differential equation. We provide computer simulated solutions for this equation over regimes of interest. This paper could be of ...

  20. Interest Rate Swaps

    Directory of Open Access Journals (Sweden)

    Marina Pepić

    2014-12-01

    Full Text Available Interest rates changes have a huge impact on the business performance. Therefore, it is of great importance for the market participants to identify and adequately manage this risk. Financial derivatives are a relatively simple way of protection from adverse changes in interest rates. Interest rate swaps are particularly popular because they reduce interest rate risk to a minimum with a relatively low initial cost and without great risk, but also because of the fact that there are manymodifications of the standard swap created to better satisfy the different needs of market players.

  1. Changes in Chemical and Isotopic Composition of Groundwater During a Long Term Pumping Test in Brestovica Karst Aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Mezga, K.; Urbanc, J. [Geological Survey of Slovenia, Department of Hydrogeology, Ljubljana (Slovenia)

    2013-07-15

    A pumping test of the Klarici water supply near Brestovica was performed in August 2008, in order to determine the karst groundwater resource capacity. Groundwater was pumped for a month with a total capacity of 470 L/s. During the experiment, sampling for chemical and isotopic composition of groundwater and surface water was carried out. Intensive pumping in dry meteorological conditions caused a lowering of the water table and changes in the chemical and isotopic composition of pumped water. Local meteoric waters are infiltrated into the aquifer at a lower mean altitude; therefore the {delta}{sup 18}O is enriched with the heavy oxygen isotope. The duration of pumping resulted in changes in the isotopic composition of oxygen due to a greater impact of the intergranular Soca River aquifer on the karst aquifer. On the basis of isotope composition it was possible to quantify the impact of the Soca River on the karst aquifer. (author)

  2. Interest rates mapping

    Science.gov (United States)

    Kanevski, M.; Maignan, M.; Pozdnoukhov, A.; Timonin, V.

    2008-06-01

    The present study deals with the analysis and mapping of Swiss franc interest rates. Interest rates depend on time and maturity, defining term structure of the interest rate curves (IRC). In the present study IRC are considered in a two-dimensional feature space-time and maturity. Exploratory data analysis includes a variety of tools widely used in econophysics and geostatistics. Geostatistical models and machine learning algorithms (multilayer perceptron and Support Vector Machines) were applied to produce interest rate maps. IR maps can be used for the visualisation and pattern perception purposes, to develop and to explore economical hypotheses, to produce dynamic asset-liability simulations and for financial risk assessments. The feasibility of an application of interest rates mapping approach for the IRC forecasting is considered as well.

  3. Fate of Organic Matters in a Soil Erosion Context : Qualitative and Quantitative Monitoring in a Karst Hydrosystem

    Science.gov (United States)

    Quiers, M.; Gateuille, D.; Perrette, Y.; Naffrechoux, E.; David, B.; Malet, E.

    2017-12-01

    Soils are a key compartments of hydrosystems, especially in karst aquifers which are characterized by fast hydrologic responses to rainfalls. In steady state, soils are efficient filters preventing karst water from pollutions. But agricultural or forestry land uses can alter or even reverse the role of soils. Thus , soils can act as pollution sources rather than pollution filters. In order to manage water quality together with man activities in karst environment, the development of new tools and procedures designed to monitor the fate of soil organic matter are needed. This study reports two complementary methods applied in a moutain karst system impacted by anthropic activities and environmental stresses. A continuous monitoring of water fluorescence coupled with punctual sampling was analyzed by chemiometric methods and allowed to discriminate the type of organic matter transferred through the karst system along the year (winter / summer) and hydrological stages. As a main result, the modelisation of organic carbone fluxes is dominated by a colloidal or particulate part during highwaters, and a main part dissolved in solution during low water, demonstrating the change of organic carbone source. To confirm this result, a second method was used based on the observation of Polycyclic Aromatic Hydrocarbons (PAH) profiles. Two previous studies (Perrette et al 2013, Schwarz et al 2011) led to opposite conclusions about the fate of PAH from soil to groundwaters. This opposition leads to a potential use of PAH profiles (low molecular weight less hydrophobic ones versus high molecular weight more hydrophobic ones) as an indicator of soil erosion. We validate that use by the anaylsis of these PAH profiles for low and high waters (floods). These results demonstrate if needed the high vulnerability of karst system to soil erosion, and propose a new proxy to record soils erosion in groundwaters and in natural archives as stalagmites or sediments.

  4. Investigating Hydrogeologic Controls on Sandhill Wetlands in Covered Karst with 2D Resistivity and Ground Penetrating Radar

    Science.gov (United States)

    Downs, C. M.; Nowicki, R. S.; Rains, M. C.; Kruse, S.

    2015-12-01

    In west-central Florida, wetland and lake distribution is strongly controlled by karst landforms. Sandhill wetlands and lakes are sand-filled upland basins whose water levels are groundwater driven. Lake dimensions only reach wetland edges during extreme precipitation events. Current wetland classification schemes are inappropriate for identifying sandhill wetlands due to their unique hydrologic regime and ecologic expression. As a result, it is difficult to determine whether or not a wetland is impacted by groundwater pumping, development, and climate change. A better understanding of subsurface structures and how they control the hydrologic regime is necessary for development of an identification and monitoring protocol. Long-term studies record vegetation diversity and distribution, shallow ground water levels and surface water levels. The overall goals are to determine the hydrologic controls (groundwater, seepage, surface water inputs). Most recently a series of geophysical surveys was conducted at select sites in Hernando and Pasco County, Florida. Electrical resistivity and ground penetrating radar were employed to image sand-filled basins and the top of the limestone bedrock and stratigraphy of wetland slopes, respectively. The deepest extent of these sand-filled basins is generally reflected in topography as shallow depressions. Resistivity along inundated wetlands suggests the pools are surface expressions of the surficial aquifer. However, possible breaches in confining clay layers beneath topographic highs between depressions are seen in resistivity profiles as conductive anomalies and in GPR as interruptions in otherwise continuous horizons. These data occur at sites where unconfined and confined water levels are in agreement, suggesting communication between shallow and deep groundwater. Wetland plants are observed outside the historic wetland boundary at many sites, GPR profiles show near-surface layers dipping towards the wetlands at a shallower

  5. Karst and Caves of the Black Hills, South Dakota, USA; Karst y cuevas de las Black Hills, Dakota del Sur, EE.UU

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, A. N.

    2016-07-01

    The caves of the Black Hills are located in Carboniferous limestone and dolomite of the Madison Formation in western South Dakota. The climate is semi-arid, and surface karst features are few. Entrances to known caves are rather small, and the two largest caves, Wind Cave and Jewel Cave, were discovered only in the late 1880s and in 1900, respectively. Intermittent exploration and mapping have been conducted by local volunteers, National Park Service staff, and the National Speleological Society. Jewel Cave, in Jewel Cave National Monument, contains 290 km of mapped passages; and Wind Cave, in Wind Cave National Park, contains 230 km. They are the third and sixth longest known caves in the world. (Author)

  6. Single event time series analysis in a binary karst catchment evaluated using a groundwater model (Lurbach system, Austria).

    Science.gov (United States)

    Mayaud, C; Wagner, T; Benischke, R; Birk, S

    2014-04-16

    The Lurbach karst system (Styria, Austria) is drained by two major springs and replenished by both autogenic recharge from the karst massif itself and a sinking stream that originates in low permeable schists (allogenic recharge). Detailed data from two events recorded during a tracer experiment in 2008 demonstrate that an overflow from one of the sub-catchments to the other is activated if the discharge of the main spring exceeds a certain threshold. Time series analysis (autocorrelation and cross-correlation) was applied to examine to what extent the various available methods support the identification of the transient inter-catchment flow observed in this binary karst system. As inter-catchment flow is found to be intermittent, the evaluation was focused on single events. In order to support the interpretation of the results from the time series analysis a simplified groundwater flow model was built using MODFLOW. The groundwater model is based on the current conceptual understanding of the karst system and represents a synthetic karst aquifer for which the same methods were applied. Using the wetting capability package of MODFLOW, the model simulated an overflow similar to what has been observed during the tracer experiment. Various intensities of allogenic recharge were employed to generate synthetic discharge data for the time series analysis. In addition, geometric and hydraulic properties of the karst system were varied in several model scenarios. This approach helps to identify effects of allogenic recharge and aquifer properties in the results from the time series analysis. Comparing the results from the time series analysis of the observed data with those of the synthetic data a good agreement was found. For instance, the cross-correlograms show similar patterns with respect to time lags and maximum cross-correlation coefficients if appropriate hydraulic parameters are assigned to the groundwater model. The comparable behaviors of the real and the

  7. Monitoring plant water status and rooting depth for precision irrigation in the vineyards of Classic Karst

    Science.gov (United States)

    Savi, Tadeja; Moretti, Elisa; Dal Borgo, Anna; Petruzzellis, Francesco; Stenni, Barbara; Bertoncin, Paolo; Dreossi, Giuliano; Zini, Luca; Martellos, Stefano; Nardini, Andrea

    2017-04-01

    The extreme summer drought and heat waves that occurred in South-Europe in 2003 and 2012 have led to the loss of more than 50% of winery production in the Classic Karst (NE Italy). The irrigation of vineyards in this area is not appropriately developed and, when used, it does not consider the actual water status and needs of plants, posing risks of inappropriate or useless usage of large water volumes. The predicted future increase in frequency and severity of extreme climate events poses at serious risk the local agriculture based on wine business. We monitored seasonal trends of pre-dawn (Ψpd) and minimum (Ψmin) leaf water potential, and stomatal conductance (gL) of 'Malvasia' grapevine in one mature (MV, both in 2015 and 2016) and one young vineyard (YV, in 2016). Moreover, we extracted xylem sap form plant stems and soil water from samples collected in nearby caves, by cryo-vacuum distillation. We also collected precipitation and irrigation water in different months. Oxygen isotope composition (δ18O) of atmospheric, plant, soil and irrigation water was analyzed to get information about rooting depth. In 2015, at the peak of summer aridity, two irrigation treatments were applied according to traditional management practices. The treatments were performed in a sub-area of the MV, followed by physiological analysis and yield measurements at grape harvest. In 2016, the soil water potential (Ψsoil) at 50 cm depth was also monitored throughout the season. Under harsh environmental conditions the apparently deep root system ensured relatively favorable plant water status in both MV and YV and during both growing seasons. The Ψsoil at 50 cm depth gradually decreased as drought progressed, reaching a minimum value of about -1.7 MPa, far more negative than Ψpd recorded in plants (about -0.5 MPa). In July, significant stomatal closure was observed, but Ψmin never surpassed the critical threshold of -1.3 MPa, indicating that irrigation was not needed. The xylem sap

  8. Soil erosion evolution and spatial correlation analysis in a typical karst geomorphology using RUSLE with GIS

    Science.gov (United States)

    Zeng, Cheng; Wang, Shijie; Bai, Xiaoyong; Li, Yangbing; Tian, Yichao; Li, Yue; Wu, Luhua; Luo, Guangjie

    2017-07-01

    Although some scholars have studied soil erosion in karst landforms, analyses of the spatial and temporal evolution of soil erosion and correlation analyses with spatial elements have been insufficient. The lack of research has led to an inaccurate assessment of environmental effects, especially in the mountainous area of Wuling in China. Soil erosion and rocky desertification in this area influence the survival and sustainability of a population of 0.22 billion people. This paper analyzes the spatiotemporal evolution of soil erosion and explores its relationship with rocky desertification using GIS technology and the revised universal soil loss equation (RUSLE). Furthermore, this paper analyzes the relationship between soil erosion and major natural elements in southern China. The results are as follows: (1) from 2000 to 2013, the proportion of the area experiencing micro-erosion and mild erosion was at increasing risk in contrast to areas where moderate and high erosion are decreasing. The area changes in this time sequence reflect moderate to high levels of erosion tending to convert into micro-erosion and mild erosion. (2) The soil erosion area on the slope, at 15-35°, accounted for 60.59 % of the total erosion area, and the corresponding soil erosion accounted for 40.44 %. (3) The annual erosion rate in the karst region decreased much faster than in the non-karst region. Soil erosion in all of the rock outcrop areas indicates an improving trend, and dynamic changes in soil erosion significantly differ among the various lithological distribution belts. (4) The soil erosion rate decreased in the rocky desertification regions, to below moderate levels, but increased in the severe rocky desertification areas. The temporal and spatial variations in soil erosion gradually decreased in the study area. Differences in the spatial distribution between lithology and rocky desertification induced extensive soil loss. As rocky desertification became worse, the erosion

  9. Ecological Stoichiometric Characteristics of Two Typical Plantations in the Karst Ecosystem of Southwestern China

    Directory of Open Access Journals (Sweden)

    Danbo Pang

    2018-01-01

    Full Text Available Reforestation has been widely adopted to restore soil fertility and ecosystem service function in the rocky desertification region of southwestern China. However, there has been limited research concerning the stoichiometry of carbon (C, nitrogen (N, and phosphorus (P and nutrient resorption rate of plantations in karst ecosystems. In this study, we selected plantations of Pinus yunnanensis Franch. (PY and Eucalyptus maideni F. Muell. (EM in Yunnan Province. The C, N, and P concentrations and the C:N:P stoichiometry in different soil layers (0–10 cm, 10–20 cm, and 20–30 cm were examined. The nutrient limitation and nutrient resorption efficiency were also analyzed. The leaf C and N concentrations in the PY plantation were higher than that in the EM plantation; the P concentration demonstrated the opposite trend, both in green and senesced leaves. Soil C, N, and P concentrations in the EM plantation were much greater than in the PY plantation at all three depths and decreased with the depth of the soil. In addition, the high ratios of C:P, N:P, C:Available P, and N:Available P in soil coupled with the ratios of N:P in leaves indicate that the EM plantation has a greater P deficiency than the PY plantation. In the EM plantation, the relatively low P concentrations in senesced leaves indicates efficient TP (Total phosphorus resorption, which highlights that the high reuse proficiency of P could have favored moderating P limitation in the karst ecosystem. This research aids in understanding the stoichiometric characteristics that mediate forest properties, and provides a basis for management of vegetation in karst ecosystems.

  10. Geologic and climatic controls on streamflow generation processes in a complex eogenetic karst basin

    Science.gov (United States)

    Vibhava, F.; Graham, W. D.; Maxwell, R. M.

    2012-12-01

    Streamflow at any given location and time is representative of surface and subsurface contributions from various sources. The ability to fully identify the factors controlling these contributions is key to successfully understanding the transport of contaminants through the system. In this study we developed a fully integrated 3D surface water-groundwater-land surface model, PARFLOW, to evaluate geologic and climatic controls on streamflow generation processes in a complex eogenetic karst basin in North Central Florida. In addition to traditional model evaluation criterion, such as comparing field observations to model simulated streamflow and groundwater elevations, we quantitatively evaluated the model's predictions of surface-groundwater interactions over space and time using a suite of binary end-member mixing models that were developed using observed specific conductivity differences among surface and groundwater sources throughout the domain. Analysis of model predictions showed that geologic heterogeneity exerts a strong control on both streamflow generation processes and land atmospheric fluxes in this watershed. In the upper basin, where the karst aquifer is overlain by a thick confining layer, approximately 92% of streamflow is "young" event flow, produced by near stream rainfall. Throughout the upper basin the confining layer produces a persistent high surficial water table which results in high evapotranspiration, low groundwater recharge and thus negligible "inter-event" streamflow. In the lower basin, where the karst aquifer is unconfined, deeper water tables result in less evapotranspiration. Thus, over 80% of the streamflow is "old" subsurface flow produced by diffuse infiltration through the epikarst throughout the lower basin, and all surface contributions to streamflow originate in the upper confined basin. Climatic variability provides a secondary control on surface-subsurface and land-atmosphere fluxes, producing significant seasonal and

  11. Ethnogeological Cultural Model of Karst Derived from Traditional Knowledge in Puerto Rico and Dominican Republic

    Science.gov (United States)

    Garcia, A.; Semken, S. C.; Brandt, E.

    2017-12-01

    Ethnogeology is the scientific study of human relationships with and knowledge of the Earth system, and is typically investigated within the context of a specific culture. Many indigenous and local systems of environmental and place knowledge incorporate empirical observations and culturally framed interpretations of geological features and processes. Ethnogeological interpretations may differ from those of conventional mainstream geoscience, but they are validated by their direct relevance to long-term cultural and environmental resilience and sustainability, typically in challenging environments. Ethnogeologic findings can enrich geoscientific knowledge bases for further research, and inform place-based geoscience education that has been shown to engage and enrich students from diverse underrepresented minority backgrounds. Ethnogeological research blends methods from field geology with methods from field ethnography: such as participant observation, free listing, participatory mapping, and cultural consensus analysis among other methods from rapid participatory assessment. We report here on an ongoing field study in Puerto Rico (PR) and the Dominican Republic (DR) on ethnogeological knowledge of karst topography, geology, and hydrogeology among local cultural indigenous communities such as the Boricua jíbaro and the Dominican campesino. Applied focused ethnographic fieldwork results suggest a good fit for the cultural consensus model about geological processes among culturally expert consultants in DR (4.604) and PR (4.669), as well as competence average with values of 0.552 and 0.628 respectively. This suggests the existence of a regional cultural model for the domain of karst that is shared between PR and DR populations that reside in or near karst terrain. Additional data in support of the cultural model include stories, analogies, and family history using participant observation, and participatory mapping.

  12. Fluviokarst and classical karst: Examples from the Dinarics (Krk Island, Northern Adriatic, Croatia)

    Science.gov (United States)

    Benac, Čedomir; Juračić, Mladen; Matičec, Dubravko; Ružić, Igor; Pikelj, Kristina

    2013-02-01

    In order to contribute to the debate on the role of fluvial erosion in the shaping of karst, two nearby areas with different karstic landscapes were compared. Areas A and B are located relatively close to each other on the southern side of the Krk Island (Adriatic Sea, Croatia). Both areas are composed of similar limestone with a very high CaCO3 content. Area A is a typical doline or polygonal type ("classical") of karst with numerous dolines (up to 57/km2) covered with terra rossa (red soil) and Mediterranean maquis shrubland. Dolines are located in zones which correspond to the strike of the main geological structures. Dry karstic valleys are visible only on gently inclined coastal slopes bordering the karstic plateau. In contrast, area B is typical of a bare karst landscape with a strong (palaeo)fluvial imprint. The dolines are absent, and the bedrock is only sporadically covered with terra rossa. Palaeogene marls have been observed in a few elongated depressions and in the coastal zone of area B. Along steep coastal slopes, valleys (up to 460 m/km2) are cut into the carbonates. The traces of episodic surface flows are visible in some of these valleys, in contrast to the valleys in area A. Remnants of a disrupted ancient fluvial network are clearly visible on the elevated karstic plateau in area B. Differences in the recent morphology are attributed mainly to varying thicknesses of the Palaeogene impermeable marly cover, and the intensity of tectonics in the two areas.

  13. Bryophyte communities as biomonitors of environmental factors in the Goujiang karst bauxite, southwestern China.

    Science.gov (United States)

    Wang, Shiqiang; Zhang, Zhaohui; Wang, Zhihui

    2015-12-15

    Bauxite mining on karst results in several ecological and environmental issues including heavy metal pollution, soil erosion and the destruction of vegetation. In turn, these may affect the distribution of plant communities and endanger human health. In general, bryophytes (mosses, liverworts and hornworts) are pioneer plants, lacking roots, vascular systems and well-developed cuticles. Due to their high sensitivity to the environment, they are often used to monitor air and soil pollution. A total of 25 bryophyte taxa from 19 genera and 9 families were recorded on Goujiang karst bauxite near the city of Zunyi in the Guizhou Province of southwestern China. Eleven principal bryophyte communities were identified, most of which consisted of only one species (monospecific assemblage), although the proportion of these single-species communities differed at the six locations. The levels of heavy metals also differed in soil from the six locations: iron, 8748.9-10,023μg/g; zinc, 146.7-240.9μg/g; copper, 24.6-60.4μg/g; and nickel, 35.6-95.1μg/g. A canonical correspondence analysis (CCA) of the bryophyte communities and environmental variables revealed the effect of gradient (slope), altitude and heavy metals in the soil on the distribution of the principal bryophyte communities. More than 36% of bryophyte taxa identified reproduced asexually by gemmae, as gemmiferous bryophyte communities tolerate substrates with high levels of heavy metals more readily than non-gemmiferous communities do. The distribution of heavy metals in the soil is reflected in the distribution of the bryophyte communities. The distribution characteristics of the principal bryophyte communities and of the gemmiferous bryophyte communities are useful in monitoring heavy metal pollution in karst bauxite. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Litter Decomposition Rate of Karst Ecosystem at Gunung Cibodas, Ciampea Bogor Indonesia

    Directory of Open Access Journals (Sweden)

    Sethyo Vieni Sari

    2016-05-01

    Full Text Available The study aims to know the productivity of litter and litter decomposition rate in karst ecosystem. This study was conducted on three altitude of 200 meter above sea level (masl, 250 masl and 300 masl in karst ecosystem at Gunung Cibodas, Ciampea, Bogor. Litter productivity measurement performed using litter-trap method and litter-bag method was used to know the rate of decomposition. Litter productivity measurement results showed that the highest total of litter productivity measurement results was on altitude of 200 masl (90.452 tons/ha/year and the lowest was on altitude of 300 masl (25.440 tons/ha/year. The litter productivity of leaves (81.425 ton/ha/year showed the highest result than twigs (16.839 ton/ha/year, as well as flowers and fruits (27.839 ton/ha/year. The rate of decomposition was influenced by rainfall. The decomposition rate and the decrease of litter dry weight on altitude of 250 masl was faster than on the altitude of 200 masl and 300 masl. The dry weight was positively correlated to the rate of decomposition. The lower of dry weight would affect the rate of decomposition become slower. The average of litter C/N ratio were ranged from 28.024%--28.716% and categorized as moderate (>25. The finding indicate that the rate of decomposition in karst ecosystem at Gunung Cibodas was slow and based on C/N ratio of litter showed the mineralization process was also slow.

  15. Differences between caves with and without bats in a Brazilian karst habitat

    Directory of Open Access Journals (Sweden)

    Camila G. Torquetti

    2017-10-01

    Full Text Available ABSTRACT. Since bats shelter in roosts during their period of diurnal inactivity, the quality and availability of roosts are important aspects of their ecology. Karst areas have great potential for the availability of day roosts, since they form caves, which serve as bat shelters. Here we characterize the caves used by bats in a preserved karst area of Southeastern Brazil. Using logistic regression analysis we identified the cave characteristics that influence bat occupation. Sixty-six caves were characterized based on measurements of internal height and width, height and width of the entrance(s of the cave, number of entrances, maximum horizontal development of cave, and internal temperature and humidity. In nineteen months we found 14 species in 32 caves. Most species were eventually recorded in multiple caves, with the exception of D. rotundus, G. soricina and A. planirostris, which were always found in the same caves. Desmodus rotundus showed maternity roost fidelity. We found no differences in microclimate between the caves that are occupied and those that are not. In other words, the microclimate of the caves studied herein can be characterized as stable over the years. The only predictor affecting the presence of bats in the study area was the cave’s maximum horizontal development: the caves that are occupied have greater horizontal development. Based on our results, we conclude that bats occupy many of the caves and that some species are more frequent in certain caves than in others, including some roosts that are used as maternity roosts. These findings indicate that these caves are important resources for the bats in the karst environment studied, and should be preserved.

  16. Taking the mystery out of mathematical model applications to karst aquifers—A primer

    Science.gov (United States)

    Kuniansky, Eve L.

    2014-01-01

    Advances in mathematical model applications toward the understanding of the complex flow, characterization, and water-supply management issues for karst aquifers have occurred in recent years. Different types of mathematical models can be applied successfully if appropriate information is available and the problems are adequately identified. The mathematical approaches discussed in this paper are divided into three major categories: 1) distributed parameter models, 2) lumped parameter models, and 3) fitting models. The modeling approaches are described conceptually with examples (but without equations) to help non-mathematicians understand the applications.

  17. A new small karst-dwelling species of Cyrtodactylus (Reptilia: Squamata: Gekkonidae) from Java, Indonesia.

    Science.gov (United States)

    Riyanto, Awal; Bauer, Aaron M; Yudha, Donan Satria

    2014-04-07

    A new small karst-dwelling species of the genus Cyrtodactylus is described from East Java and Special Province of Yogyakarta, Indonesia. Cyrtodactylus semiadii sp. nov. is a small species (SVL to 47.1 mm in females, 42.1 mm in males) distinguished from all other congeners by unique characters combination: short, robust, cylindrical tail, indistinct ventrolateral folds, absence of precloacal groove, absence of enlarged femoral scales, absence of precloacal and femoral pores and lack of enlarged median subcaudal scales. It is the third member of the genus recorded from Java. 

  18. Source, variability, and transformation of nitrate in a regional karst aquifer: Edwards aquifer, central Texas.

    Science.gov (United States)

    Musgrove, MaryLynn; Opsahl, Stephen P.; Mahler, Barbara J.; Herrington, Chris; Sample, Thomas; Banta, John

    2016-01-01

    Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO3−) loading to surface and groundwater. We investigate variability and sources of NO3− in a regional karst aquifer system, the Edwards aquifer of central Texas. Samples from streams recharging the aquifer, groundwater wells, and springs were collected during 2008–12 from the Barton Springs and San Antonio segments of the Edwards aquifer and analyzed for nitrogen (N) species concentrations and NO3− stable isotopes (δ15N and δ18O). These data were augmented by historical data collected from 1937 to 2007. NO3− concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO3− concentrations in the Barton Springs segment is controlled by occurrence of individual storms and multi-annual wet-dry cycles, whereas the lack of short-term variability in groundwater in the San Antonio segment indicates the dominance of transport along regional flow paths. In both segments, longer-term increases (years to decades) in NO3− concentrations cannot be attributed to hydrologic conditions; rather, isotopic ratios and land-use change indicate that septic systems and land application of treated wastewater might be the source of increased loading of NO3−. These results highlight the vulnerability of karst aquifers to NO3− contamination from urban wastewater. An analysis of N-species loading in recharge and discharge for the Barton Springs segment during 2008–10 indicates an overall mass balance in total N, but recharge contains higher concentrations of organic N and lower concentrations of NO3−than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates that subaqueous nitrification of organic N in the aquifer, as opposed to in soils, might be a previously

  19. Negative effects of land-use changes in the karst setting of Apulia, southern Italy

    Science.gov (United States)

    Parise, Mario

    2010-05-01

    Apulia is an almost entirely carbonate region in south-eastern Italy, representing the heel of the boot-shaped Italian peninsula. Due to its location in the heart of the Mediterranean basin, and its geographical configuration, which in some way connects the Italian territory to the eastward lands, it had a long history of human settlements, as shown by the many remarkable prehistoric findings that have been recorded in this area during the last century. The flatness of the region, derived from the geologic origin of Apulia as the undeformed foreland of the Southern Apenninic Chain of Italy, together with its NW-SE oriented peninsula configuration and the long coastlines, are at the origin of the good-continuity occupation by man during the different phases of human history. The original karst landscape, characterized by absence of surface runoff, due to rapid infiltration of surface water into the network of karst conduits and fissures within the carbonate rock mass, was with time modified by man. Agriculture initially developed in the narrow strips of land where the presence of residual deposits (terre rosse) allowed the establishment of thin soil layers, and/or in small depressions where water was able to be kept for a longer time within the epikarst. Outside of these sites, the karst landscape typically consisted of stony plateaus and subdued rounding hills. To gain further space to agricultural practices, part of the surrounding stony areas was cleared of rocks: the latter were extracted by hand, and used to build dry stone walls to delimitate the properties, and/or to act as a barrier to soil erosion or to work as terrace walls in the sectors with higher gradients. At the same time, extraction and re-use of carbonate rocks originated some of the typical rural architecture common in Apulia, from "trulli" to "pagliare" and, later on, to "masserie" (the old countryside mansions). In the last decades of XX century, thanks to the use of modern technologies and

  20. Characterisation of karst hydrogeology in Western Ireland using geophysical and hydraulic modelling techniques

    Directory of Open Access Journals (Sweden)

    T. McCormack

    2017-04-01

    New hydrological insights for the region: Results suggest two primary pathways of northwards groundwater flow in the catchment, a fault which discharges offshore, and a ∼2 m diameter karst conduit running underneath the catchment lowlands against the prevailing geological dip. This conduit, whose existence was suspected but never confirmed, links a large ephemeral lake to the coast where it discharges intertidally. Hydraulic modelling indicates that the conduit network is a complex mixture of constrictions with multiple inlets and outlets. Two ephemeral lakes are shown to be hydraulically discontinuous, either drained separately or linked by a low pressure channel.

  1. Source, variability, and transformation of nitrate in a regional karst aquifer: Edwards aquifer, central Texas

    Energy Technology Data Exchange (ETDEWEB)

    Musgrove, M., E-mail: mmusgrov@usgs.gov [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Opsahl, S.P. [U.S. Geological Survey, 5563 DeZavala, Ste. 290, San Antonio, TX 78249 (United States); Mahler, B.J. [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Herrington, C. [City of Austin Watershed Protection Department, Austin, TX 78704 (United States); Sample, T.L. [U.S. Geological Survey, 19241 David Memorial Dr., Ste. 180, Conroe, TX 77385 (United States); Banta, J.R. [U.S. Geological Survey, 5563 DeZavala, Ste. 290, San Antonio, TX 78249 (United States)

    2016-10-15

    Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO{sub 3}{sup −}) loading to surface and groundwater. We investigate variability and sources of NO{sub 3}{sup −} in a regional karst aquifer system, the Edwards aquifer of central Texas. Samples from streams recharging the aquifer, groundwater wells, and springs were collected during 2008–12 from the Barton Springs and San Antonio segments of the Edwards aquifer and analyzed for nitrogen (N) species concentrations and NO{sub 3}{sup −} stable isotopes (δ{sup 15}N and δ{sup 18}O). These data were augmented by historical data collected from 1937 to 2007. NO{sub 3}{sup −} concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO{sub 3}{sup −} concentrations in the Barton Springs segment is controlled by occurrence of individual storms and multi-annual wet-dry cycles, whereas the lack of short-term variability in groundwater in the San Antonio segment indicates the dominance of transport along regional flow paths. In both segments, longer-term increases (years to decades) in NO{sub 3}{sup −} concentrations cannot be attributed to hydrologic conditions; rather, isotopic ratios and land-use change indicate that septic systems and land application of treated wastewater might be the source of increased loading of NO{sub 3}{sup −}. These results highlight the vulnerability of karst aquifers to NO{sub 3}{sup −} contamination from urban wastewater. An analysis of N-species loading in recharge and discharge for the Barton Springs segment during 2008–10 indicates an overall mass balance in total N, but recharge contains higher concentrations of organic N and lower concentrations of NO{sub 3}{sup −} than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates

  2. Source, variability, and transformation of nitrate in a regional karst aquifer: Edwards aquifer, central Texas

    International Nuclear Information System (INIS)

    Musgrove, M.; Opsahl, S.P.; Mahler, B.J.; Herrington, C.; Sample, T.L.; Banta, J.R.

    2016-01-01

    Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO 3 − ) loading to surface and groundwater. We investigate variability and sources of NO 3 − in a regional karst aquifer system, the Edwards aquifer of central Texas. Samples from streams recharging the aquifer, groundwater wells, and springs were collected during 2008–12 from the Barton Springs and San Antonio segments of the Edwards aquifer and analyzed for nitrogen (N) species concentrations and NO 3 − stable isotopes (δ 15 N and δ 18 O). These data were augmented by historical data collected from 1937 to 2007. NO 3 − concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO 3 − concentrations in the Barton Springs segment is controlled by occurrence of individual storms and multi-annual wet-dry cycles, whereas the lack of short-term variability in groundwater in the San Antonio segment indicates the dominance of transport along regional flow paths. In both segments, longer-term increases (years to decades) in NO 3 − concentrations cannot be attributed to hydrologic conditions; rather, isotopic ratios and land-use change indicate that septic systems and land application of treated wastewater might be the source of increased loading of NO 3 − . These results highlight the vulnerability of karst aquifers to NO 3 − contamination from urban wastewater. An analysis of N-species loading in recharge and discharge for the Barton Springs segment during 2008–10 indicates an overall mass balance in total N, but recharge contains higher concentrations of organic N and lower concentrations of NO 3 − than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates that subaqueous nitrification of organic N in the aquifer, as opposed to in soils, might be a

  3. Biochemical mechanisms of resistance to p-nitrochlorobenzene of karst caves microorganisms

    Directory of Open Access Journals (Sweden)

    O. S. Suslova

    2015-08-01

    Full Text Available The biochemical mechanisms of resistance to persistent organic xenobiotic p-nitrochlorobenzene (NCB of bacterial strains isolated from two cave clays ecosystems – Mushkarova Yama (Podolia, Ukraine and Kuybyshevskaya (Western Caucasus, Abkhazia have been established. It has been determined that chemoorganotrophic karst caves strains could interact with NCB and transform it reducing the nitro group with formation of p-chloroaniline (ClA followed by further destruction of NCB aromatic ring. This explained high resistance of caves strains to NCB. The studied strains could potentially be used in wastewater treatment from nitrochloraromatic compounds.

  4. Interest Rates and Inflation

    OpenAIRE

    Coopersmith, Michael

    2011-01-01

    A relation between interest rates and inflation is presented using a two component economic model and a simple general principle. Preliminary results indicate a remarkable similarity to classical economic theories, in particular that of Wicksell.

  5. INTEREST AND READING MOTIVATION

    Directory of Open Access Journals (Sweden)

    Alhamdu Alhamdu

    2016-05-01

    Full Text Available The purpose of this study is to examine the relationship between interest and reading motivation based on literature review. The concept of the interest portrayed as a psychological state that occurs during interaction between individual and specific topic, object or activity including process of willingness, increased attention, concentration and positive feeling to the topic, object or activity. Meanwhile reading motivation emphasized to mental readiness, willingness and refers to beliefs and perception of individual to engage in reading activity. Some researchers were identified factors that influenced reading motivation such as intrinsic and extrinsic factors, self-concept and value of reading, and interest. In general, the literature review described that have positive relationship between interest and reading motivation.

  6. Debenture Interest Rates

    Data.gov (United States)

    Department of Housing and Urban Development — Interest rates to be paid on debentures issued with respect to a loan or mortgage insured by the Federal Housing Commissioner under the provisions of the National...

  7. Survey research.

    Science.gov (United States)

    Alderman, Amy K; Salem, Barbara

    2010-10-01

    Survey research is a unique methodology that can provide insight into individuals' perspectives and experiences and can be collected on a large population-based sample. Specifically, in plastic surgery, survey research can provide patients and providers with accurate and reproducible information to assist with medical decision-making. When using survey methods in research, researchers should develop a conceptual model that explains the relationships of the independent and dependent variables. The items of the survey are of primary importance. Collected data are only useful if they accurately measure the concepts of interest. In addition, administration of the survey must follow basic principles to ensure an adequate response rate and representation of the intended target sample. In this article, the authors review some general concepts important for successful survey research and discuss the many advantages this methodology has for obtaining limitless amounts of valuable information.

  8. A New Methodology for Open Pit Slope Design in Karst-Prone Ground Conditions Based on Integrated Stochastic-Limit Equilibrium Analysis

    Science.gov (United States)

    Zhang, Ke; Cao, Ping; Ma, Guowei; Fan, Wenchen; Meng, Jingjing; Li, Kaihui

    2016-07-01

    Using the Chengmenshan Copper Mine as a case study, a new methodology for open pit slope design in karst-prone ground conditions is presented based on integrated stochastic-limit equilibrium analysis. The numerical modeling and optimization design procedure contain a collection of drill core data, karst cave stochastic model generation, SLIDE simulation and bisection method optimization. Borehole investigations are performed, and the statistical result shows that the length of the karst cave fits a negative exponential distribution model, but the length of carbonatite does not exactly follow any standard distribution. The inverse transform method and acceptance-rejection method are used to reproduce the length of the karst cave and carbonatite, respectively. A code for karst cave stochastic model generation, named KCSMG, is developed. The stability of the rock slope with the karst cave stochastic model is analyzed by combining the KCSMG code and the SLIDE program. This approach is then applied to study the effect of the karst cave on the stability of the open pit slope, and a procedure to optimize the open pit slope angle is presented.

  9. [Relationships between landscape structure and rocky desertification in karst region of northwestern Guangxi].

    Science.gov (United States)

    Zhang, Xiao-nan; Wang, Ke-lin; Chen, Hong-song; Zhang, Wei

    2008-11-01

    By using canonical correspondence analysis (CCA), sixteen landscape indices were adopted to quantitatively analyze the relationships between the landscape structure and rocky desertification in karst region of Huanjiang County, Guangxi Province. The results showed that the first and the second ordination axis of CCA were strongly correlated to the factors of average patch area, average dry land patch area, landscape shape index, and landscape aggregation index. The potential rocky desertification in the region was highly positively correlated with the average dry land patch area and the average fractal dimensions of dry land and shrub land, but negatively correlated with the patch numbers of dry land. Light rocky desertification had obvious positive correlations with the fractal dimension index, average fractal dimension of unused land, and patch numbers of shrub land; while moderate and strong rocky desertification had high positive correlations with the average unused land patch area but negative correlation with the average fractal dimension of shrub land. To some extent, rocky desertification degree might be represented by the values of landscape indices. The gradient variation in karst rocky desertification along landscape structure was clearly presented by the results of CCA.

  10. The challenge and future of rocky desertification control in karst areas in southwest China

    Science.gov (United States)

    Zhang, J. Y.; Dai, M. H.; Wang, L. C.; Zeng, C. F.; Su, W. C.

    2016-01-01

    Karst rocky desertification occurs after vegetation deteriorates as a result of intensive land use, which leads to severe water loss and soil erosion and exposes basement rocks, creating a rocky landscape. Karst rocky desertification is found in humid areas in southwest China, the region most seriously affected by rocky desertification in the world. In order to promote ecological restoration and help peasants out of poverty, the Chinese government carried out the first phase of a rocky desertification control project from 2006 to 2015, which initially contained the expansion of rocky desertification. Currently, the Chinese government is prepared to implement the second phase of the rocky desertification control project, and therefore it is essential to summarise the lessons learned over the last 10 years of the first phase. In this paper, we analyse the driving social and economic factors behind rocky desertification, summarise the scientific research on rocky desertification in the region, and finally identify the main problems facing rocky desertification control. In addition, we put forward several policy suggestions that take into account the perspective of local peasants, scientific research, and China's economic development and urbanisation process. These suggestions include promoting the non-agriculturalization of household livelihoods, improving ecological compensation, strengthening the evaluation of rocky desertification control and dynamic monitoring, and strengthening research on key ecological function recovery technologies and supporting technologies.

  11. Analysis of methods to estimate spring flows in a karst aquifer.

    Science.gov (United States)

    Sepúlveda, Nicasio

    2009-01-01

    Hydraulically and statistically based methods were analyzed to identify the most reliable method to predict spring flows in a karst aquifer. Measured water levels at nearby observation wells, measured spring pool altitudes, and the distance between observation wells and the spring pool were the parameters used to match measured spring flows. Measured spring flows at six Upper Floridan aquifer springs in central Florida were used to assess the reliability of these methods to predict spring flows. Hydraulically based methods involved the application of the Theis, Hantush-Jacob, and Darcy-Weisbach equations, whereas the statistically based methods were the multiple linear regressions and the technology of artificial neural networks (ANNs). Root mean square errors between measured and predicted spring flows using the Darcy-Weisbach method ranged between 5% and 15% of the measured flows, lower than the 7% to 27% range for the Theis or Hantush-Jacob methods. Flows at all springs were estimated to be turbulent based on the Reynolds number derived from the Darcy-Weisbach equation for conduit flow. The multiple linear regression and the Darcy-Weisbach methods had similar spring flow prediction capabilities. The ANNs provided the lowest residuals between measured and predicted spring flows, ranging from 1.6% to 5.3% of the measured flows. The model prediction efficiency criteria also indicated that the ANNs were the most accurate method predicting spring flows in a karst aquifer.

  12. Strategy for definition and protection of east Tennessee karst groundwater basins

    International Nuclear Information System (INIS)

    Rubin, P.A.; Lemiszki, P.J.; Poling, R.S.

    1992-01-01

    This paper describes and gives suggestions for protecting the bedrock geology of eastern Tennessee which is typical of the southern Appalachian Valley and Ridge province. Carbonate beds (limestones and dolomites) of the Knox and Chickamauga Groups are bounded by non-carbonate beds, most of which strike northeast and dip steeply (10 degrees--45 degrees) to the southeast. The carbonate aquifers are maturely karstified and are extremely vulnerable to contaminant infiltration, thus necessitating appropriate land use planning focused on their environmental sensitivity. Urban expansion is resulting in greater land development in karst regions. Planned and existing activities produce wastes that may potentially leach into underlying karst systems. This waste may flow rapidly and untreated for many miles along strike. The potential degradation of aquifers and receiving streams due to the cumulative waste loading of numerous small enterprises may be more environmentally destructive than a few hazardous waste sites. Costs to remediate contaminated water supplies and streams can be in the millions of dollars versus the substantially lower costs of prudent land use planning

  13. Karst tiankengs as refugia for indigenous tree flora amidst a degraded landscape in southwestern China.

    Science.gov (United States)

    Su, Yuqiao; Tang, Qiming; Mo, Fuyan; Xue, Yuegui

    2017-06-26

    We conducted floristic and community analyses to compare the floristic composition, forest structure, taxonomic richness, and species diversity between two tiankeng (large doline, or sinkhole) habitats and two outside-tiankeng habitats of forest fragments in a degraded karst area in southwestern China. We found remarkably higher taxonomic richness in the tiankeng habitats than in the outside-tiankeng habitats at the species, generic, and familial levels. The inside-tiankeng habitats had higher floristic diversity but lower dominance. The remarkably higher uniqueness at all taxonomic levels and the much larger tree size in the two tiankeng habitats than in the outside-tiankeng habitats demonstrated the old-growth and isolated nature of the tiankeng flora. Plot-scale species richness, Shannon-Wiener index, Pielou's evenness, and Berger-Parker dominance significantly differed across habitats. Heterogeneity in floristic composition at the species, generic, and familial levels was extremely significant across habitats. In pairwise comparisons, except for the Chuandong Tiankeng-Shenmu Tiankeng pair, all the pairs showed significant between-habitat heterogeneity in floristic composition. Our results suggest that as oases amidst the degraded karst landscape, tiankengs serve as modern refugia that preserve old-growth forest communities with their rich floristic diversity, and can provide a model for habitat conservation and forest restoration in that area.

  14. Evaluation of Water Resource Security Based on an MIV-BP Model in a Karst Area

    Directory of Open Access Journals (Sweden)

    Liying Liu

    2018-06-01

    Full Text Available Evaluation of water resource security deserves particular attention in water resource planning and management. A typical karst area in Guizhou Province, China, was used as the research area in this paper. First, based on data from Guizhou Province for the past 10 years, the mean impact value–back propagation (MIV-BP model was used to analyze the factors influencing water resource security in the karst area. Second, 18 indices involving five aspects, water environment subsystem, social subsystem, economic subsystem, ecological subsystem, and human subsystem, were selected to establish an evaluation index of water resource security. Finally, a BP artificial neural network model was constructed to evaluate the water resource security of Guizhou Province from 2005 to 2014. The results show that water resource security in Guizhou, which was at a moderate warning level from 2005 to 2009 and a critical safety level from 2010 to 2014, has generally improved. Groundwater supply ratio, industrial water utilization rate, water use efficiency, per capita grain production, and water yield modulus were the obstacles to water resource security. Driving factors were comprehensive utilization rate of industrial solid waste, qualifying rate of industrial wastewater, above moderate rocky desertification area ratio, water requirement per unit gross domestic product (GDP, and degree of development and utilization of groundwater. Our results provide useful suggestions on the management of water resource security in Guizhou Province and a valuable reference for water resource research.

  15. Potential impacts on regional climate due to land degradation in the Guizhou Karst Plateau of China

    International Nuclear Information System (INIS)

    Gao, Jiangbo; Wu, Shaohong; Xue, Yongkang

    2013-01-01

    The possible regional climatic effects of land condition change in the Guizhou Karst Plateau (GKP), which has experienced serious Karst Rocky Desertification (KRD) in the past decades, were investigated in this study using the Weather Research and Forecasting (WRF) regional climate model. It was shown that when compared with validation datasets, the WRF showed a high ability to downscale NCEP-DOE Reanalysis-2, which provided the initial and lateral boundary conditions for WRF, especially for the precipitation simulation. After land degradation over the GKP, the net radiation and evaporation were reduced mainly within the desertification area, consistent with the reduction in rainfall and the increase in surface temperature there. The southwest monsoon flow from the Bay of Bengal was weakened over the adjacent area to the northeast, influencing the East Asian summer monsoon. Meanwhile, the weaker low-layer anti-cyclone and the stronger horizontal convergence enhanced vertical motion in the southeastern coastal areas. Furthermore, owing to the decreased surface heating in the degradation experiment, the lifting over the GKP and neighboring regions to the east was limited, which resulted in a reduced rainfall within the GKP and strengthened the ascending motion downstream over 114°–122° E. Such circulation differences favored an increase in moisture flux and clouds, thereby causing more precipitation in coastal areas of southeast China. (letter)

  16. Quantitative Evaluation of Ecosystem Health in a Karst Area of South China

    Directory of Open Access Journals (Sweden)

    Shengzi Chen

    2016-10-01

    Full Text Available The purpose of this study is to propose a GIS-based mechanism for diagnosing karst rocky desertification (KRD ecosystem health. Using the Huajiang Demonstration Area in Guizhou Province as a case study, this research offers a multi-factor indicator system for diagnosing KRD ecosystem health. A set of geologic, environmental, and socio-economic health indicators were developed based on remote sensing images from field-investigation, hydrological, and meteorological monitoring data. With the use of grid GIS technology, this study gives an indicator for diagnosing the spatial expression of desertification at a 5 m × 5 m grid scale. Using spatial overlaying technology based on grid data, the temporal and spatial dynamics of ecosystem health in the Huajiang Demonstration Area were tracked over a 10 year time span. The results of the analysis indicate that ecosystem health in the Huajiang Demonstration Area varies regionally, and has overall improved over time. The proportion of healthy area increased from 3.7% in 2000 to 8.2% in 2010. However, unhealthy and middle-health areas still accounted for 78.7% of the total area by 2010. The most obvious improvement of ecosystem health was in an area where comprehensive control measures for curbing KRD were implemented. These results suggest that comprehensive control of KRD can effectively mitigate ecosystem deterioration and improve ecosystem health in karst regions of South China.

  17. Mycobacteria of clinical interest

    International Nuclear Information System (INIS)

    Casal, M.

    1986-01-01

    This book is based upon a symposium on mycobacteria of clinical interest. Due to the multidisciplinary participation of, among others, microbiologists, clinicians, immunologists and epidemiologists, a very wide and thorough presentation of the present state of clinical research in this field is ensured. Topics of particular interest included in this volume were the new antimicrobial agents active against mycobacteria; new therapeutic possibilities; a system of rapid diagnosis of tuberculosis and mycobacteriosis; mycobacteriosis in AIDS; progress in immunopathology of tuberculosis and leprosy; progress in bacteriology and vaccination in leprosy; progress in immunological diagnosis and new epidemiological biovars of M. tuberculosis. (Auth.)

  18. Development of a process-oriented vulnerability concept for water travel time in karst aquifers-case study of Tanour and Rasoun springs catchment area.

    Science.gov (United States)

    Hamdan, Ibraheem; Sauter, Martin; Ptak, Thomas; Wiegand, Bettina; Margane, Armin; Toll, Mathias

    2017-04-01

    Key words: Karst aquifer, water travel time, vulnerability assessment, Jordan. The understanding of the groundwater pathways and movement through karst aquifers, and the karst aquifer response to precipitation events especially in the arid to semi-arid areas is fundamental to evaluate pollution risks from point and non-point sources. In spite of the great importance of the karst aquifer for drinking purposes, karst aquifers are highly sensitive to contamination events due to the fast connections between the land-surface and the groundwater (through the karst features) which is makes groundwater quality issues within karst systems very complicated. Within this study, different methods and approaches were developed and applied in order to characterise the karst aquifer system of the Tanour and Rasoun springs (NW-Jordan) and the flow dynamics within the aquifer, and to develop a process-oriented method for vulnerability assessment based on the monitoring of different multi-spatially variable parameters of water travel time in karst aquifer. In general, this study aims to achieve two main objectives: 1. Characterization of the karst aquifer system and flow dynamics. 2. Development of a process-oriented method for vulnerability assessment based on spatially variable parameters of travel time. In order to achieve these aims, different approaches and methods were applied starting from the understanding of the geological and hydrogeological characteristics of the karst aquifer and its vulnerability against pollutants, to using different methods, procedures and monitored parameters in order to determine the water travel time within the aquifer and investigate its response to precipitation event and, finally, with the study of the aquifer response to pollution events. The integrated breakthrough signal obtained from the applied methods and procedures including the using of stable isotopes of oxygen and hydrogen, the monitoring of multi qualitative and quantitative parameters

  19. Social developmnet of ecologically sensitive rural areas: Case studies of the Moravian Karst (Czech Republic) and the Devetashko Plato (Bulgaria)

    Czech Academy of Sciences Publication Activity Database

    Zapletalová, Jana; Stefanová, D.; Vaishar, Antonín; Stefanov, P.; Dvořák, Petr; Tcherkezova, E.

    3-4, 3-4 (2016), s. 65-84 ISSN 0204-7209 Institutional support: RVO:68145535 Keywords : social development * rural sensitive areas * Devetashko Plato * Bulgaria * Moravian karst - Czech Republic Subject RIV: DE - Earth Magnetism, Geodesy, Geography OBOR OECD: Cultural and economic geography http://geoproblems.eu/wp-content/uploads/2017/04/2016_34/4_zapletalova.pdf

  20. Community composition and cold tolerance of soil Collembola in a collapse karst doline with strong microclimate inversion

    Czech Academy of Sciences Publication Activity Database

    Raschmanová, N.; Miklisová, D.; Kováč, L.; Šustr, Vladimír

    2015-01-01

    Roč. 70, č. 6 (2015), s. 802-811 ISSN 0006-3088 Grant - others:VEGA(SK) 1/0199/14; VEGA(SK) 1/3267/06 Institutional support: RVO:60077344 Keywords : cold tolerance * collapse doline * karst landform * microclimatic gradient * soil Collembola Subject RIV: EG - Zoology Impact factor: 0.719, year: 2015

  1. Soil movements and surface erosion rates on rocky slopes in the mountain areas of the karst region of Southwest China

    Science.gov (United States)

    Zhang, X. B.; Bai, X. Y.; Long, Y.

    2012-04-01

    The karst region of Southwest China with an area of 54 × 104 km2 is one of the largest karst areas in the world and experiences subtropical climate. Hill-depressions are common landforms in the mountain areas of this region. Downslope soil movement on the ground by surface water erosion and soil sinking into underground holes by creeping or pipe erosion are mayor types of soil movements on rocky carbonate slopes. The 137Cs technique was used to date the sediment deposits in six karst depressions, to estimate average surface erosion rates on slopes from their catchments. The estimates of soil loss rates obtained from this study evidenced considerable variability. A value of 1.0 t km-2 year-1 was obtained for a catchment under original dense karst forest, but the erosion rates ranged between 19.3 t km-2 year-1 and 48.7 t km-2 year-1 in four catchments under secondary forest or grasses, where the original forest cover had been removed in the Ming and Qing dynasties, several hundred years ago. The highest rate of 1643 t km-2 year-1 was obtained for a catchment underlain by clayey carbonate rocks, where the soil cover was thicker and more extensive than in the other catchments and extensive land reclamation for cultivation had occurred during the period 1979-1981, immediately after the Cultural Revolution.

  2. Epigene and Hypogene Gypsum Karst Manifestations of the Castile Formation: Eddy County, New Mexico and Culberson County, Texas, USA

    Directory of Open Access Journals (Sweden)

    Stafford Kevin W.

    2008-07-01

    Full Text Available Permian evaporites of the Castile Formation crop out over ~1,800 km2 in the western Delaware Basin (Eddy County, New Mexico and Culberson County, Texas, USA with abundant and diverse karst manifestations. Epigene karst occurs as well-developed karren on exposed bedrock, while sinkholes dominate the erosional landscape, including both solutional and collapse forms. Sinkhole analyses suggest that more than half of all sinks are the result of upward stoping of subsurface voids, while many solutional sinks are commonly the result of overprinting of collapsed forms. Epigene caves are laterally limited with rapid aperture decreases away from insurgence, with passages developed along fractures and anticline fold axes. Hypogene karst occurs as diverse manifestations, forming the deepest and longest caves within the region as well as abundant zones of brecciation. Hypogene caves exhibit a wide range of morphologies from complex maze and anastomotic patterns to simple, steeply dipping patterns, but all hypogene caves exhibit morphologic features (i.e. risers, outlet cupolas and half-tubes that provide a definitive suite of evidence of dissolution within a mixed convection (forced and free convection hydrologic system. Extensive blanket breccias, abundant breccia pipes and numerous occurrences of calcitized evaporites indicate widespread hypogene speleogenesis throughout the entire Castile Formation. Although most cave and karst development within the Castile outcrop region appears to have hypogene origins, epigene processes areactively overprinting features, creating a complex speleogenetic evolution within the Castile Formation.

  3. Dating of speleothems in non-karst caves - methodological aspects and practical application, Polish Outer Carpathians case study

    Czech Academy of Sciences Publication Activity Database

    Urban, J.; Margielewski, W.; Hercman, H.; Žák, Karel; Zernitska, V.; Pawlak, J.; Schejbal-Chwastek, M.

    2015-01-01

    Roč. 59, Supplement 1 (2015), s. 185-210 ISSN 0372-8854 Institutional support: RVO:67985831 Keywords : non-karst caves * speleothem dating * landslide * Polish Outer Carpathians Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.103, year: 2015

  4. CITOGENETICS EFFECTS INDUCED BY THE ASCORBIC ACID TREATMENT OF LARIX DECIDUA MILL. SSP. CARPATICA AND PICEA ABIES (L. KARST

    Directory of Open Access Journals (Sweden)

    Ioana Ieremia

    2006-08-01

    Full Text Available The paper present the influence of ascorbic acid upon the mitotic division of Larix decidua Mill ssp. carpatica and Picea abies (L. Karst. The treatment is applied of two variants, germinated seed in ascorbic acid (variantAand germinated seeds in disttilate water, than treated with ascorbic acid in 3 concentrations (variant B.

  5. Environmental hydrochemical and stabile isotope methods used to characterise the relation between karst water and surface water

    Directory of Open Access Journals (Sweden)

    Romeo Eftimi

    2017-03-01

    Full Text Available Karst aquifers are characterized by high heterogeneity of groundwater flow. The classical study methods such as boreholes, pumping tests, and point observations give important data but cannot be extended to the entire aquifer. However the environmental hydrochemical and stabile isotope methods could give important information about large scale aquifer characterization. Some study examples from Albania, shown in this paper, demonstrate the successful application of the isotope methods, which are more powerful if applied in combination with hydrochemical ones, for the identification of the karst water recharge sources. Among the isotope methods the altitude effect seems to be more indicative for the solution of the problem concerned. For characterising the lithology of karst rocks and the physical aspects of karst aquifers (type of groundwater flow the combined use of some hydrochemical parameters like the water conductivity, total hardness, ionic ratios rCa/ rMg, rSO4/r/mg, CO2 pressure and the indexes of calcite and (Sic and of dolomite saturation (Sid, result very useful.

  6. Life on a block of limestone: Evolutionary, ecological and geological dynamics of isolated malacofaunas on tropical karst

    NARCIS (Netherlands)

    Schilthuizen, M.

    2011-01-01

    The karst formations of southeast Asia are a wonderful evolutionary and ecological experiment, and a sad example of observable extinction (Clements et al., 2006). In this paper, I shall focus on those in Malaysia and, in particular, on the land snail faunas that they support.

  7. The first “osteolepiform” tetrapodomorph (Sarcopterygii) from the Paleozoic sequences of the Moravian Karst (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Poukarová, Hedvika; Weiner, Tomáš

    2016-01-01

    Roč. 60, č. 3 (2016), s. 737-745 ISSN 1641-7291 R&D Projects: GA ČR GA14-18183S Institutional support: RVO:67985831 Keywords : Tetrapodomorpha * “Osteolepiformes”, * cosmine * Famennian * Moravo-Silesian Basin * Moravian Karst Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.129, year: 2016

  8. Genotype-specific microsatellite (SSR) markers for the sugarcane germplasm in the Karst region of Guizhou, China

    Science.gov (United States)

    It is the first report on SSR-based molecular evaluation of genetic variability among sugarcane genotypes from the Karst region of China that provides useful information for local sugarcane improvement. Eighteen sugarcane genotypes including 13 active cultivars and five elite QT-series clones bred l...

  9. Book Review: Caves and Karst of the Yorkshire Dales

    Science.gov (United States)

    Westaway, Rob

    2015-10-01

    The British Cave Research Association (BCRA) is the research division of the British Caving Association (BCA), itself the principal society in Britain for those interested in caving, with activities including provision of training and safety certification for cavers and managing access to caves. Although some UK cave-related research is carried out by academics, this tends to be restricted to archaeological investigations of caves that have served as human habitations, and to be focused more on the occupants than the caves themselves. In contrast, most cave exploration is undertaken as a leisure activity, under the auspices of clubs affiliated to the BCA/BCRA, this being indeed virtually the only field of Earth science where amateur investigators can continue to make significant discoveries. Many cave explorers are also affiliated with academic researchers, such as managers of dating laboratories; the synergy between these two groups is highly productive, having resulted for instance in the discovery and exploration in recent years of the vast Ogof Draenen cave system in South Wales, which probably dates back to the Early Pleistocene (e.g., Farrant et al., 2014).

  10. Application, advantages and limitations of high-density gravimetric surveys compared with three-dimensional geological modelling in dolomite stability investigations

    OpenAIRE

    Breytenbach, I J; Bosch, P J A

    2011-01-01

    The article discusses the nature of the gravimetric survey as applied and used in dolomite stability investigations on areas underlain by the Chuniespoort Group in South Africa. A short discussion is given on the gravimetric survey procedure along with its uses and alternative methods. Finally, two case studies illustrate the application of the method on a high-density survey grid spacing in comparison with three-dimensional geological modelling based on the lithology and karst weathering hor...

  11. Spousal Conflicts of Interest

    Science.gov (United States)

    Lewis, Shana R.

    2005-01-01

    Romantic relationships bud and sometimes bloom in the school district workplace. When those relationships involve a sitting member of a school board or an administrator with responsibility for managing other employees, questions about a conflict of interest will be raised. Most states have laws prohibiting a public official from taking official…

  12. Special Interest Groups.

    Science.gov (United States)

    Degi, Bruce J.

    1999-01-01

    Offers a reflection on the shootings at Columbine High School in Littleton, Colorado, on April 20, 1999. Notes how every special-interest group has used the tragedy to support its own point of view, and concludes that teachers have become bystanders in the education of America's children. (SR)

  13. Regional scale hydrologic modeling of a karst-dominant geomorphology: The case study of the Island of Crete

    Science.gov (United States)

    Malagò, Anna; Efstathiou, Dionissios; Bouraoui, Fayçal; Nikolaidis, Nikolaos P.; Franchini, Marco; Bidoglio, Giovanni; Kritsotakis, Marinos

    2016-09-01

    Crete Island (Greece) is a karst dominated region that faces limited water supply and increased seasonal demand, especially during summer for agricultural and touristic uses. In addition, due to the mountainous terrain, interbasin water transfer is very limited. The resulting water imbalance requires a correct quantification of available water resources in view of developing appropriate management plans to face the problem of water shortage. The aim of this work is the development of a methodology using the SWAT model and a karst-flow model (KSWAT, Karst SWAT model) for the quantification of a spatially and temporally explicit hydrologic water balance of karst-dominated geomorphology in order to assess the sustainability of the actual water use. The application was conducted in the Island of Crete using both hard (long time series of streamflow and spring monitoring stations) and soft data (i.e. literature information of individual processes). The KSWAT model estimated the water balance under normal hydrological condition as follows: 6400 Mm3/y of precipitation, of which 40% (2500 Mm3/y) was lost through evapotranspiration, 5% was surface runoff and 55% percolated into the soil contributing to lateral flow (2%), and recharging the shallow (9%) and deep aquifer (44%). The water yield was estimated as 22% of precipitation, of which about half was the contribution from spring discharges (9% of precipitation). The application of the KSWAT model increased our knowledge about water resources availability and distribution in Crete under different hydrologic conditions. The model was able to capture the hydrology of the karst areas allowing a better management and planning of water resources under scarcity.

  14. Both temperature fluctuations and East Asian monsoons have driven plant diversification in the karst ecosystems from southern China.

    Science.gov (United States)

    Kong, Hanghui; Condamine, Fabien L; Harris, A J; Chen, Junlin; Pan, Bo; Möller, Michael; Hoang, Van Sam; Kang, Ming

    2017-11-01

    Karst ecosystems in southern China are species-rich and have high levels of endemism, yet little is known regarding the evolutionary processes responsible for the origin and diversification of karst biodiversity. The genus Primulina (Gesneriaceae) comprises ca. 170 species endemic to southern China with high levels of ecological (edaphic) specialization, providing an exceptional model to study the plant diversification in karsts. We used molecular data from nine chloroplast and 11 nuclear regions and macroevolutionary analyses to assess the origin and cause of species diversification due to palaeoenvironmental changes and edaphic specialization in Primulina. We found that speciation was positively associated with changes in past temperatures and East Asian monsoons through the evolutionary history of Primulina. Climatic change around the mid-Miocene triggered an early burst followed by a slowdown of diversification rate towards the present with the climate cooling. We detected different speciation rates among edaphic types, and transitions among soil types were infrequently and did not impact the overall speciation rate. Our findings suggest that both global temperature changes and East Asian monsoons have played crucial roles in floristic diversification within the karst ecosystems in southern China, such that speciation was higher when climate was warmer and wetter. This is the first study to directly demonstrate that past monsoon activity is positively correlated with speciation rate in East Asia. This case study could motivate further investigations to assess the impacts of past environmental changes on the origin and diversification of biodiversity in global karst ecosystems, most of which are under threat. © 2017 John Wiley & Sons Ltd.

  15. Estimating the proportion of groundwater recharge from flood events in relation to total annual recharge in a karst aquifer

    Science.gov (United States)

    Dvory, N. Z.; Ronen, A.; Livshitz, Y.; Adar, E.; Kuznetsov, M.; Yakirevich, A.

    2017-12-01

    Sustainable groundwater production from karstic aquifers is primarily dictated by its recharge rate. Therefore, in order to limit over-exploitation, it is essential to accurately quantify groundwater recharge. Infiltration during erratic floods in karstic basins may contribute substantial amount to aquifer recharge. However, the complicated nature of karst systems, which are characterized in part by multiple springs, sinkholes, and losing/gaining streams, present a large obstacle to accurately assess the actual contribution of flood water to groundwater recharge. In this study, we aim to quantify the proportion of groundwater recharge during flood events in relation to the annual recharge for karst aquifers. The role of karst conduits on flash flood infiltration was examined during four flood and artificial runoff events in the Sorek creek near Jerusalem, Israel. The events were monitored in short time steps (four minutes). This high resolution analysis is essential to accurately estimating surface flow volumes, which are of particular importance in arid and semi-arid climate where ephemeral flows may provide a substantial contribution to the groundwater reservoirs. For the present investigation, we distinguished between direct infiltration, percolation through karst conduits and diffused infiltration, which is most affected by evapotranspiration. A water balance was then calculated for the 2014/15 hydrologic year using the Hydrologic Engineering Center - Hydrologic Modelling System (HEC-HMS). Simulations show that an additional 8% to 24% of the annual recharge volume is added from runoff losses along the creek that infiltrate through the karst system into the aquifer. The results improve the understanding of recharge processes and support the use of the proposed methodology for quantifying groundwater recharge.

  16. Adapted hydropower-driven water supply system: assessment of an underground application in an Indonesian karst area

    Science.gov (United States)

    Oberle, P.; Ikhwan, M.; Stoffel, D.; Nestmann, F.

    2016-09-01

    Populated karst landscapes can be found all over the world, although their natural boundary conditions mostly lead to distinct challenges regarding a sustainable water supply. Especially in developing and emerging countries, this situation aggravates since appropriate technologies and water management concepts are rarely available. Against this background, the interdisciplinary, German-Indonesian joint project " Integrated Water Resources Management (IWRM) Indonesia", funded by the German Federal Ministry of Education and Research (BMBF), focused on the development and exemplary implementation of adapted techniques to remedy the partly severe water scarcity in the region Gunung Sewu. This karst area, widely known as " Java's poorhouse", is located on the southern coast of Java Island and distinctly suffers from the mentioned constraints. Under the aegis of the Karlsruhe Institute of Technology (KIT), the conceptual and technical achievements of the "IWRM Indonesia" joint research project are characterized by a high potential for multiplication not only for karst areas but also for non-karst regions. One of the project's major accomplishments is the erection of an innovative hydropower-driven water supply facility located in a karst cave 100 m below ground and continuously supplying tens of thousands of people with fresh water. Referring to the plant's innovative character and the demanding conditions on-site, the implementation was a highly iterative process leading to today's autonomous operation by an Indonesian public authority. Based on the experiences gained during design, construction, operation and monitoring phase, this paper introduces an implementation approach for adapted technologies as well as a comprising technical and economical assessment of the plant's operation.

  17. Analysis of human induced changes in a karst landscape - the filling of dolines in the Kras plateau, Slovenia.

    Science.gov (United States)

    Kovačič, Gregor; Ravbar, Nataša

    2013-03-01

    A comprehensive analysis of the increased pressure on karst landscapes due to expansive economic and urban development is presented with the aim of evaluating changes in land use and their deleterious effects on karst relief forms. The study focuses on two areas surrounding the relatively quickly growing settlements of Hrpelje-Kozina and Divača on the Kras plateau (Slovenia) that have been subjected to intensive urban and business development and traffic since the motorway was brought to their vicinity fifteen years ago. National legislation loopholes and technological improvement were the cause of the commonly unsupervised human encroachment which caused the widespread degradation of the landscape. By comparing different topographical and ortophotographical materials from the past four decades and by detailed field inspection of land use and environmental changes, as well as the morphometrical characterization of dolines, the following results have been found: due to the population growth in the past four decades (39% and 50%, respectively), an increase of settlement area by 18 and 11 percentage points took place. Consequently, between 25 and 27% of dolines have disappeared or have been extensively modified (filled up and leveled). According to the local spatial plans, an additional 18% to 28% dolines are endangered. Broad human induced changes in the karst landscape have resulted in a noticeable increase in landscape deterioration, which is consistent with similar phenomena observed in other regions. Due to the extreme susceptibility of the karst to human activities that may lead to the degradation of its exceptional esthetic and environmental value, the alteration of karst processes such as corrosion, endangering of unique habitats and the quality of non-renewable natural resources, it is necessary to promptly define measures for its protection at the national level. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. MAX and Survey Linkages

    Data.gov (United States)

    U.S. Department of Health & Human Services — CMS is interested in linking MAX files with survey data, including four surveys conducted by the National Center for Health Statistics (NCHS) - the National Health...

  19. Congressional interest and input

    International Nuclear Information System (INIS)

    Donnelly, W.H.

    1985-01-01

    While congressional interest in nonproliferation policy has been evident since the 1940s, the 1970s were propitious for efforts by Congress to exert influence in this sphere. Its suspicions of the executive branch had been stirred by controversies over Vietnam and Watergate at the beginning of the decade; by the end of the decade, Congress was able to curtail the unrestrained freedom of the executive branch to carry out the vaguely stated policies of the Atomic Energy Act of 1954. Congressional nonproliferation interests were further amplified during the decade by pressures from the expanding environmental movement, which included a strong antinuclear plank. This was to bring down the powerful Atomic Energy Commission (AEC). The Energy Reorganization Act of 1974 abolished the AEC and divided its responsibilities between the new Energy Research and Development Administration (ERDA), later to become the Department of Energy (DOE), and the new Nuclear Regulatory Commission

  20. Solicitors' conflicts of interest

    OpenAIRE

    Bamford, Colin

    2003-01-01

    Brief overview of the need for the Law Society of England and Wales to formulate new rules to address conflicts of interest situations and accommodate modern practices which have followed from the merger of firms of solicitors resulting for example in requests to act in a dispute with a former client or to represent several parties in the same commercial or financial transaction. Published in Amicus Curiae – Journal of the Society for Advanced Legal Studies at the Institute of Advanced Legal ...

  1. Forecasting interest rates with shifting endpoints

    DEFF Research Database (Denmark)

    Van Dijk, Dick; Koopman, Siem Jan; Wel, Michel van der

    2014-01-01

    We consider forecasting the term structure of interest rates with the assumption that factors driving the yield curve are stationary around a slowly time-varying mean or ‘shifting endpoint’. The shifting endpoints are captured using either (i) time series methods (exponential smoothing) or (ii......) long-range survey forecasts of either interest rates or inflation and output growth, or (iii) exponentially smoothed realizations of these macro variables. Allowing for shifting endpoints in yield curve factors provides substantial and significant gains in out-of-sample predictive accuracy, relative...... to stationary and random walk benchmarks. Forecast improvements are largest for long-maturity interest rates and for long-horizon forecasts....

  2. Public interest group involvement

    International Nuclear Information System (INIS)

    Shelley, P.

    1986-01-01

    Including public interest groups in the siting process for nuclear waste disposal facilities is of great importance. Controversial sitings often result in litigation, but involving public interest groups early in the process will lessen the change of this. They act as surrogates for the general public and should be considered as members of the team. It is important to remember though, that all public interest groups are different. In choosing public panels such as public advisory committees, members should not be chosen on the basis of some quota. Opposition groups should not be excluded. Also, it is important to put the right person in charge of the committee. The goal of public involvement is to identify the conflicts. This must be done during the decision process, because conflicts must be known before they can be eliminated. Regarding litigation, it is important to ease through and around legal battles. If the siting process has integrity and a good faith effort has been shown, the court should uphold the effort. In addition, it is important to be negotiable and to eliminate shortcuts

  3. A method of mapping sinkhole susceptibility using a geographic information system : a case study for interstates in the karst counties of Virginia.

    Science.gov (United States)

    2015-02-01

    This study proposes the use of a geographic information system (GIS) to create a susceptibility map, pinpointing : regions in the karst counties of Virginia, in particular, along interstates, most susceptible to future sinkhole : development, determi...

  4. Situational Interest in Engineering Design Activities

    Science.gov (United States)

    Bonderup Dohn, Niels

    2013-08-01

    The aim of the present mixed-method study was to investigate task-based situational interest of sixth grade students (n = 46), between 12 and 14 years old, during an eight-week engineering design programme in a Science & Technology-class. Students' interests were investigated by means of a descriptive interpretative analysis of qualitative data from classroom observations and informal interviews. The analysis was complemented by a self-report survey to validate findings and determine prevalence. The analysis revealed four main sources of interest: designing inventions, trial-and-error experimentation, achieved functionality of invention, and collaboration. These sources differ in terms of stimuli factors, such as novelty, autonomy (choice), social involvement, self-generation of interest, and task goal orientation. The study shows that design tasks stimulated interest, but only to the extent that students were able to self-regulate their learning strategies.

  5. Situational interest in engineering design activities

    DEFF Research Database (Denmark)

    Dohn, Niels Bonderup

    2013-01-01

    The aim of the present mixed-method study was to investigate task-based situational interest of sixth grade students (n=46), between 12 and 14 years old, during an eight-week engineering design programme in a Science & Technology-class. Students’ interests were investigated by means...... of a descriptive interpretative analysis of qualitative data from classroom observations and informal interviews. The analysis was complemented by a self-report survey to validate findings and determine prevalence. The analysis revealed four main sources of interest: designing inventions, trial......-and-error experimentation, achieved functionality of invention, and collaboration. These sources differ in terms of stimuli factors, such as novelty, autonomy (choice), social involvement, self-generation of interest, and task goal orientation. The study shows that design tasks stimulated interest, but only to the extent...

  6. Soil erosion evolution and spatial correlation analysis in a typical karst geomorphology using RUSLE with GIS

    Directory of Open Access Journals (Sweden)

    C. Zeng

    2017-07-01

    Full Text Available Although some scholars have studied soil erosion in karst landforms, analyses of the spatial and temporal evolution of soil erosion and correlation analyses with spatial elements have been insufficient. The lack of research has led to an inaccurate assessment of environmental effects, especially in the mountainous area of Wuling in China. Soil erosion and rocky desertification in this area influence the survival and sustainability of a population of 0.22 billion people. This paper analyzes the spatiotemporal evolution of soil erosion and explores its relationship with rocky desertification using GIS technology and the revised universal soil loss equation (RUSLE. Furthermore, this paper analyzes the relationship between soil erosion and major natural elements in southern China. The results are as follows: (1 from 2000 to 2013, the proportion of the area experiencing micro-erosion and mild erosion was at increasing risk in contrast to areas where moderate and high erosion are decreasing. The area changes in this time sequence reflect moderate to high levels of erosion tending to convert into micro-erosion and mild erosion. (2 The soil erosion area on the slope, at 15–35°, accounted for 60.59 % of the total erosion area, and the corresponding soil erosion accounted for 40.44 %. (3 The annual erosion rate in the karst region decreased much faster than in the non-karst region. Soil erosion in all of the rock outcrop areas indicates an improving trend, and dynamic changes in soil erosion significantly differ among the various lithological distribution belts. (4 The soil erosion rate decreased in the rocky desertification regions, to below moderate levels, but increased in the severe rocky desertification areas. The temporal and spatial variations in soil erosion gradually decreased in the study area. Differences in the spatial distribution between lithology and rocky desertification induced extensive soil loss. As rocky desertification

  7. Human and natural impacts on fluvial and karst depressions of the Maya Lowlands

    Science.gov (United States)

    Beach, Timothy; Luzzadder-Beach, Sheryl; Dunning, Nicholas; Cook, Duncan

    2008-10-01

    This paper begins to differentiate the major drivers and chronology of erosion and aggradation in the fluvial and fluviokarst landscapes of the southern and central Maya Lowlands. We synthesize past research on erosion and aggradation and add new data from water, soils, radiocarbon dating, and archaeology to study the quantity, timing, and causes of aggradation in regional landscape depressions. Geomorphic findings come from many excavations across a landscape gradient from upland valleys, karst sinks, and fans into the coastal plain floodplains and depressions. Findings from water chemistry show that sources in the uplands have low quantities of dissolved ions but water in the coastal plains has high amounts of dissolved ions, often nearly saturated in calcium and sulfate. We found significant geomorphic complexity in the general trends in upland karst sinks. In a few instances, sediments preserve Late Pleistocene paleosols, buried 2-3 m, though many more have distinct middle to late Holocene paleosols, buried 1-2 m, after c. 2300 BP (Maya Early to Late Preclassic). From 2300-1100 BP (Late Preclassic to Classic Periods), the landscape aggraded from five main mechanisms: river flooding, climatic instability, accelerated erosion, ancient Maya landscape manipulation, and gypsum precipitation from a rise in a water table nearly saturated in calcium and sulfate ions. Evidence exists for two or three high magnitude floods, possibly driven by hurricanes. Moreover, lake-core and geophysical studies from the Petén Lakes region have shown high rates of deposition of silicate clays ('Maya Clays') starting and peaking during the Maya Preclassic and continuing to be high through the Late Classic. The main driver on upland karst depressions, the Petén lakes, upland valleys, and fans was accelerated soil erosion, but water table rise, probably driven by sea-level rise, was the main driver on the wetlands of the coastal plain because the aggraded sediments here are dominantly

  8. Interest in PSI across Sixteen Years.

    Science.gov (United States)

    Lamal, P. A.

    1984-01-01

    To determine whether interest in the personalized system of instruction (PSI) in the behavioral sciences has waned since 1968, conference papers and poster presentations dealing with PSI were surveyed. The number of papers and posters devoted to PSI peaked in the years 1972-1979 and has since clearly declined. (RM)

  9. Water exchange and pressure transfer between conduits and matrix and their influence on hydrodynamics of two karst aquifers with sinking streams

    Science.gov (United States)

    Bailly-Comte, Vincent; Martin, Jonathan B.; Jourde, Hervé; Screaton, Elizabeth J.; Pistre, Séverin; Langston, Abigail

    2010-05-01

    SummaryKarst aquifers are heterogeneous media where conduits usually drain water from lower permeability volumes (matrix and fractures). For more than a century, various approaches have used flood recession curves, which integrate all hydrodynamic processes in a karst aquifer, to infer physical properties of the movement and storage of groundwater. These investigations typically only consider flow to the conduits and thus have lacked quantitative observations of how pressure transfer and water exchange between matrix and conduit during flooding could influence recession curves. We present analyses of simultaneous discharge and water level time series of two distinctly different karst systems, one with low porosity and permeability matrix rocks in southern France, and one with high porosity and permeability matrix rocks in north-central Florida (USA). We apply simple mathematical models of flood recession using time series representations of recharge, storage, and discharge processes in the karst aquifer. We show that karst spring hydrographs can be interpreted according to pressure transfer between two distinct components of the aquifer, conduit and matrix porosity, which induce two distinct responses at the spring. Water exchange between conduits and matrix porosity successively control the flow regime at the spring. This exchange is governed by hydraulic head differences between conduits and matrix, head gradients within conduits, and the contrast of permeability between conduits and matrix. These observations have consequences for physical interpretations of recession curves and modeling of karst spring flows, particularly for the relative magnitudes of base flow and quick flow from karst springs. Finally, these results suggest that similar analyses of recession curves can be applied to karst aquifers with distinct physical characteristics utilizing well and spring hydrograph data, but information must be known about the hydrodynamics and physical properties of

  10. Spatial-temporal Evolution of Karst Rocky Desertification and Future Trends Based on CA-Markov Methods in Typical Karst Valley

    Directory of Open Access Journals (Sweden)

    CHEN Fei

    2018-02-01

    Full Text Available Karst rocky desertification(KRDhas become the most serious ecological disaster in Southwest China. It is very important and much-needed to explore the rule of spatial-temporal evolution of KRD for ecological restoration and sustainable development of the region. In this paper, the improved accurate remote sensing image interpreting method and CA-Markov prediction method were used to explore the spatial-temporal evolution rule of KRD in the study area from 1990 to 2021 based on the long time line remote sensing image of the year of 1990, 2004 and 2016. The results were as follows:the spatial -temporal evolution rule of KRD presented "first deterioration and then improvement" in the study area at nearly 30 years. The deterioration of KRD was affected by high intensity overload human activities and natural disasters in 1990-2004, which made the ecological environment deterioration. However, the KRD had gradually improved with the implementation of a series of governance projects, and a large number of rural labor forces were liberated from the land in 2004-2016, which made the natural environment restoration, and ecological system was getting better and better. At the same time, the trend of KRD evolution was showing improvement from the predicted years of 2016-2021 and the ecological environment in the region continued to become better.

  11. The Ladstattschacht cave shaft - tracer hydrological investigation of a site of organic pollution in the Alpine karst system; Der Ladstattschacht - tracerhydrologische Untersuchung einer organischen Altlast im alpinen Karst

    Energy Technology Data Exchange (ETDEWEB)

    Goldscheider, N. [Karlsruhe Univ. (T.H.) (Germany). Lehrstuhl fuer Angewandte Geologie

    1998-12-31

    The Ladstattschacht is a 47 m deep cave shaft in the Schwarzwasser valley (state of Vorarlberg, Austrian Alps) that was completely filled up with waste from private and communal sewage plants until 1975. A multi tracing experiment using three different fluorescent tracers was carried out in order to evaluate the risk potential of this waste site. The organic shaft fill itself, a pothole nearby the Ladstattschacht and an active swallow hole served as injection points. It could be demonstrated that all karstic springs in the Schwarzwasser valley are affected by seepage water from this waste site. Comparison of breakthrough curves allowed to determine retardation processes in the shaft fill and the unsaturated zone and to characterize the karst groundwater flow system. (orig.) [Deutsch] Der Ladstattschacht im Schwarzwassertal (Vorarlberg, Oesterreich) ist ein 47 m tiefer Hoehlenschacht, der bis 1975 als wilde Deponie fuer Klaerschlaemme verwendet wurde. Um das von dieser organischen Altlast ausgehende Gefaehrdungspotential zu bewerten, wurde ein kombinierter Markierungsversuch mit 3 verschiedenen Fluoreszenztracern durchgefuehrt. Dabei dienten die Schachtfuellung, ein benachbarter Naturschacht und eine aktive Schwinde als Eingabestellen. Es konnte belegt werden, dass saemtliche Karstquellen im Schwarzwassertal von Sickerwaessern aus dem Ladstattschacht erreicht werden. Durch den Vergleich der Durchgangskurven konnten sowohl die Retardationsvorgaenge in der Schachtfuellung und in der ungesaettigten Zone, als auch die Abstromverhaeltnisse der Karstentwaesserung charakterisiert werden. (orig.)

  12. Recharge estimation in semi-arid karst catchments: Central West Bank, Palestine

    Science.gov (United States)

    Jebreen, Hassan; Wohnlich, Stefan; Wisotzky, Frank; Banning, Andre; Niedermayr, Andrea; Ghanem, Marwan

    2018-03-01

    Knowledge of groundwater recharge constitutes a valuable tool for sustainable management in karst systems. In this respect, a quantitative evaluation of groundwater recharge can be considered a pre-requisite for the optimal operation of groundwater resources systems, particular for semi-arid areas. This paper demonstrates the processes affecting recharge in Palestine aquifers. The Central Western Catchment is one of the main water supply sources in the West Bank. Quantification of potential recharge rates are estimated using chloride mass balance (CMB) and empirical recharge equations over the catchment. The results showing the spatialized recharge rate, which ranges from 111-216 mm/year, representing 19-37% of the long-term mean annual rainfall. Using Water Balance models and climatological data (e. g. solar radiation, monthly temperature, average monthly relative humidity and precipitation), actual evapotranspiration (AET) is estimated. The mean annual actual evapotranspiration was about 66-70% of precipitation.

  13. Cd pollution and ecological risk assessment for mining activity zone in Karst Area

    Science.gov (United States)

    Yang, B.; He, J. L.; Wen, X. M.; Tan, H.

    2017-08-01

    The monitored soil samples were collected from farmland in the area with mining activity in Karst area in Liupanshui. In this article, moss bag technology and TSP were used simultaneously for Cd transportation and deposition in the study area. Geostatistics and GIS were then used for the spatial distribution of Cd in the soil. Afterwards, Cd pollution to the soil environment and human health was studied by using the geo-accumulation index and potential ecological risk index methods. The results indicated that atmospheric deposition is the major route of Cd pollution. A moderate to strong pollution of Cd in the area and the degree of potential ecological risk was in a high level in the study area. Furthermore, Cd pollution in Liupanshui may originate from mining activity and atmospheric deposition.

  14. Image analyses in bauxitic ores: The case of the Apulian karst bauxites

    Science.gov (United States)

    Buccione, Roberto; Sinisi, Rosa; Mongelli, Giovanni

    2015-04-01

    This study concern two different karst bauxite deposits of the Apulia region (southern Italy). These deposits outcrop in the Murge and Salento areas: the Murge bauxite (upper Cretaceous) is a typical canyon-like deposit formed in a karst depression whereas the Salento bauxite (upper Eocene - Oligocene) is the result of the erosion, remobilization and transport of older bauxitic material from a relative distant area. This particular bauxite arrangement gave the name to all the same bauxite deposits which are thus called Salento-type deposits. Bauxite's texture is essentially made of sub-circular concentric aggregates, called ooids, dispersed in a pelitic matrix. The textural properties of the two bauxitic ores, as assessed by SEM-EDX, are different. In the bauxite from the canyon-like deposit the ooids/matrix ratio is higher than in the Salento-type bauxite. Furthermore the ooids in the Salento-like bauxite are usually made by a large core surrounded by a narrow, single, accretion layer, whereas the ooids from the canyon-like deposit have a smaller core surrounded by several alternating layers of Al-hematite and boehmite (Mongelli et al., 2014). In order to explore in more detail the textural features of both bauxite deposits, particle shape analyses were performed. Image analyses and the fractal dimension have been widely used in geological studies including economic geology (e.g. Turcotte, 1986; Meakin, 1991; Deng et al., 2011). The geometric properties evaluated are amounts of ooids, average ooids size, ooids rounding and the fractal dimension D, which depends on the ooids/matrix ratio. D is the slope of a plotting line obtained using a particular counting technique on each sample image. The fractal dimension is slightly lower for the Salento-type bauxites. Since the process which led to the formation of the ooids is related to an aggregation growth involving chemical fractionation (Mongelli, 2002) a correlation among these parameters and the contents of major

  15. Assessment of hydropower potential in small karst catchments: the case of the Rocche Plateau, Central Italy

    Directory of Open Access Journals (Sweden)

    Leopardi Maurizio

    2017-01-01

    Full Text Available Estimation of flow duration characteristics is key in assessing hydropower potential in natural catchments. However, such analysis is not usually straightforward, especially in ungauged sites and/or in complex catchment areas. In this study we evaluate the feasibility of revamping of a small hydroelectric power plant, located in a karst plateau in central Italy, by assessing the hydropower potential of its feeding surface and subsurface stream network. A thorough analysis of runoff processes occurring in the examined area is carried out in order to corroborate regionalization studies based on measured specific flows in neighboring homogeneous basins. The results show an appreciable availability of water resources to be exploited for hydropower purposes.

  16. Stability numerical analysis of soil cave in karst area to drawdown of underground water level

    Science.gov (United States)

    Mo, Yizheng; Xiao, Rencheng; Deng, Zongwei

    2018-05-01

    With the underground water level falling, the reliable estimates of the stability and deformation characteristics of soil caves in karst region area are required for analysis used for engineering design. Aimed at this goal, combined with practical engineering and field geotechnical test, detail analysis on vertical maximum displacement of top, vertical maximum displacement of surface, maximum principal stress and maximum shear stress were conducted by finite element software, with an emphasis on two varying factors: the size and the depth of soil cave. The calculations on the soil cave show that, its stability of soil cave is affected by both the size and depth, and only when extending a certain limit, the collapse occurred along with the falling of underground water; Additionally, its maximum shear stress is in arch toes, and its deformation curve trend of maximum displacement is similar to the maximum shear stress, which further verified that the collapse of soil cave was mainly due to shear-failure.

  17. Resilience of Groundwater Impacted by Land Use and Climate Change in a Karst Aquifer, South China.

    Science.gov (United States)

    Guo, Fang; Jiang, Guanghui; Polk, Jason S; Huang, Xiufeng; Huang, Siyu

    2015-11-01

    Changes of groundwater flow and quality were investigated in a subtropical karst aquifer to determine the driving mechanism. Decreases in groundwater flow are more distinct in discharge zones than those in recharge and runoff zones. Long-term measurement of the represented regional groundwater outlet reveals that groundwater discharge decrease by nearly 50% during the dry season. The hydrochemistry of groundwater in the runoff and discharge zones is of poorer quality than in the recharge zone. Indications of intensive land resource exploitation and changes in land use patterns were attributed to changes in groundwater conditions since 1990, but the influence of climate change was likely from 2001, because the water temperature exhibited increasing trends at a mean rate of 0.02 °C/yr even though groundwater depth was high in the aquifer. These conclusions imply the need for further groundwater monitoring and reevaluation to understand the resilience of aquifer during urbanization and development.

  18. Photolysis of polycyclic aromatic hydrocarbons adsorbed on spruce [Picea abies (L.) Karst.] needles under sunlight irradiation

    International Nuclear Information System (INIS)

    Niu Junfeng; Chen Jingwen; Martens, D.; Quan Xie; Yang Fenglin; Kettrup, A.; Schramm, K.-W.

    2003-01-01

    Photolysis of PAHs on surfaces may determine their ultimate fate in the environment. - Photolysis of polycyclic aromatic hydrocarbons (PAHs) sorbed on surfaces of spruce [Picea abies (L.) Karst.] needles under sunlight irradiation was investigated. PAHs were produced by combustion of polyvinyl chloride (PVC), wood, high-density polyethylene (HDPE), and styrene in a stove. The factors of sunlight irradiation on the surfaces of spruce needles were taken into consideration when investigating the kinetic parameters. The photolysis of the 18 PAHs under study follows first-order kinetics. The photolysis half-lives range from 15 h for dibenzo(a,h)anthracene to 75 h for phenanthrene. Photolysis of some PAHs on surfaces of spruce needles may play an important role on the fate of PAHs in the environment

  19. Coupled decadal variability of the North Atlantic Oscillation, regional rainfall and karst spring discharges in the Campania region (southern Italy

    Directory of Open Access Journals (Sweden)

    P. De Vita

    2012-05-01

    Full Text Available Thus far, studies on climate change have focused mainly on the variability of the atmospheric and surface components of the hydrologic cycle, investigating the impact of this variability on the environment, especially with respect to the risks of desertification, droughts and floods. Conversely, the impacts of climate change on the recharge of aquifers and on the variability of groundwater flow have been less investigated, especially in Mediterranean karst areas whose water supply systems depend heavily upon groundwater exploitation.

    In this paper, long-term climatic variability and its influence on groundwater recharge were analysed by examining decadal patterns of precipitation, air temperature and spring discharges in the Campania region (southern Italy, coupled with the North Atlantic Oscillation (NAO.

    The time series of precipitation and air temperature were gathered over 90 yr, from 1921 to 2010, using 18 rain gauges and 9 air temperature stations with the most continuous functioning. The time series of the winter NAO index and of the discharges of 3 karst springs, selected from those feeding the major aqueducts systems, were collected for the same period.

    Regional normalised indexes of the precipitation, air temperature and karst spring discharges were calculated, and different methods were applied to analyse the related time series, including long-term trend analysis using smoothing numerical techniques, cross-correlation and Fourier analysis.

    The investigation of the normalised indexes highlighted the existence of long-term complex periodicities, from 2 to more than 30 yr, with differences in average values of up to approximately ±30% for precipitation and karst spring discharges, which were both strongly correlated with the winter NAO index.

    Although the effects of the North Atlantic Oscillation (NAO had already been demonstrated in the long-term precipitation and streamflow patterns of

  20. Quantifying the magnitude and spatiotemporal variation of aquatic CO2 fluxes in a sub-tropical karst catchment, Southwest China

    Science.gov (United States)

    Ding, Hu; Waldron, Susan; Newton, Jason; Garnett, Mark H.

    2017-04-01

    The role played by rivers in regional and global C budgets is receiving increasing attention. A large portion of the carbon transported via inland waters is returned to the atmosphere by carbon dioxide evasion from rivers and lakes. Karst landscapes represent an important C store on land, and are also considered to play an important role in climate regulation by consuming atmospheric CO2 during chemical weathering. However, we cannot be certain how effective this sink is if we do not know how efficiently the rivers draining karst landscapes remobilise weathered C to the atmosphere as CO2. pCO2 in karst waters is generally greater than atmospheric equilibrium, indicating that there can be a net CO2 efflux to the atmosphere. However, measurement confirming this and quantifying flux rates has been rarely conducted. Using a floating chamber method, in 2016 we directly measured CO2 fluxes from spatially distributed freshwaters (springs, sinkholes, streams and reservoirs/ponds) in the Houzhai Catchment, a karst region in SW China. Fluxes ranged from -0.5 to +267.4 μmol CO2 m-2s-1, and most sites showed seasonal variations with higher CO2 efflux rates in the wet (April - September) than dry season (October - March). There was a significant positive relationship between CO2 efflux and flow velocity, indicating that hydraulic controls on CO2 efflux from flowing water are important, while for water with little movement (sinkholes and reservoirs/ponds), pCO2 appears a more important control on efflux rates. Conditions similar to this study area may exist in many sub-tropical rivers that drain karst landscapes in South China. These waters are rich in DIC which can be an order of magnitude greater than some non-karst catchments. The large DIC pool has the potential to be a considerable source of free CO2 to the atmosphere. Considering that carbonate lithology covers a significant part of the Earth's surface, CO2 evasion in fluvial water from these regions is expected to

  1. Calcium content and high calcium adaptation of plants in karst areas of southwestern Hunan, China

    Science.gov (United States)

    Wei, Xiaocong; Deng, Xiangwen; Xiang, Wenhua; Lei, Pifeng; Ouyang, Shuai; Wen, Hongfang; Chen, Liang

    2018-05-01

    Rocky desertification is a major ecological problem of land degradation in karst areas. In these areas, the high soil calcium (Ca) content has become an important environmental factor that can affect the restoration of vegetation. Consequently, the screening of plant species that can adapt to high Ca soil environments is a critical step in vegetation restoration. In this study, three grades of rocky desertification sample areas were selected in karst areas of southwestern Hunan, China (LRD: light rocky desertification; MRD: moderate rocky desertification; and IRD: intense rocky desertification). Each grade of these sample areas had three sample plots in different slope positions, each of which had four small quadrats (one in rocky-side areas, three in non-rocky-side areas). We measured the Ca content of leaves, branches, and roots from 41 plant species, as well as soil total Ca (TCa) and exchangeable Ca (ECa) at depths of 0-15, 15-30, and 30-45 cm in each small quadrat. The results showed that the soil Ca2+ content in rocky-side areas was significantly higher than that in non-rocky-side areas (p desertification, in the order IRD > MRD > LRD. For all plant functional groups, the plant Ca content of aboveground parts was significantly higher than that of the belowground parts (p 1). The differences in Ca2+ content between the aboveground and belowground parts of the 17 dominant species were calculated, and their correlations with soil ECa content were analyzed. The results showed that these 17 species can be divided into three categories: Ca-indifferent plants, high-Ca plants, and low-Ca plants. These findings provide a vital theoretical basis and practical guide for vegetation restoration and ecosystem reconstruction in rocky desertification areas.

  2. Cansiglio Karst Plateau: 10 Years of Geodetic-Hydrological Observations in Seismically Active Northeast Italy

    Science.gov (United States)

    Grillo, Barbara; Braitenberg, Carla; Nagy, Ildikó; Devoti, Roberto; Zuliani, David; Fabris, Paolo

    2018-04-01

    Ten years' geodetic observations (2006-2016) in a natural cave of the Cansiglio Plateau (Bus de la Genziana), a limestone karstic area in northeastern Italy, are discussed. The area is of medium-high seismic risk: a strong earthquake in 1936 below the plateau (M m = 6.2) and the 1976 disastrous Friuli earthquake (M m = 6.5) are recent events. At the foothills of the karstic massif, three springs emerge, with average flow from 5 to 10 m3/s, and which are the sources of a river. The tiltmeter station is set in a natural cavity that is part of a karstic system. From March 2013, a multiparametric logger (temperature, stage, electrical conductivity) was installed in the siphon at the bottom of the cave to discover the underground hydrodynamics. The tilt records include signals induced by hydrologic and tectonic effects. The tiltmeter signals have a clear correlation to the rainfall, the discharge series of the river and the data recorded by multiparametric loggers. Additionally, the data of a permanent GPS station located on the southern slopes of the Cansiglio Massif (CANV) show also a clear correspondence with the river level. The fast water infiltration into the epikarst, closely related to daily rainfall, is distinguished in the tilt records from the characteristic time evolution of the karstic springs, which have an impulsive level increase with successive exponential decay. It demonstrates the usefulness of geodetic measurements to reveal the hydrological response of the karst. One outcome of the work is that the tiltmeters can be used as proxies for the presence of flow channels and the pressure that builds up due to the water flow. With 10 years of data, a new multidisciplinary frontier was opened between the geodetic studies and the karstic hydrogeology to obtain a more complete geologic description of the karst plateau.

  3. Flow Dependence Assessment for Fate and Transport of DNAPL in Karst Media

    Science.gov (United States)

    Carmona, M.; Padilla, I. Y.

    2017-12-01

    DNAPLs are a group of organic compounds, which exhibit high fluid density, relatively aqueous solubility, and a high level of toxicity. It is also very persistent and remains in the environment long after been released. Massive production of these compounds, their constant use and poor disposal methods have increased the occurrence of these contaminants in groundwater systems. The physico-chemical properties of DNAPL, combined with the high variation of groundwater flow causes contaminants to behave unpredictably in such aquifer. This research focuses on fate and transport of trichloroethylene (which is one of the most frequent DNAPL found) in a karstified limestone physical model (KLPM) at two different flow rates. The KLPM represents a real case of a saturated confined karst aquifer consisting of a porous limestone block enclosed in a stainless-steel tank with fifteen horizontal sampling ports. After injection of pure TCE solvent into a steady groundwater flow field, samples are taken spatially and temporally and analyzed volumetrically and analytically with HPLC. Data show pure TCE volumes are collected at the beginnings of the experiment in sampling ports located near the injection port. Results from the constructed temporal distributions curves at different spatial locations show spatial variations related to the limestone block heterogeneity. Rapid response to TCE concentrations is associated with preferential flow paths. Slow response with long tailing is indicative of diffusive transport in the rock matrix and mass transport rates limitations. Although, high flow rates show greater mass removal of TCE by dissolving its NAPL, pure TCE accumulates at all flow rates studied. Overall, results show that karstified limestone has a high capacity to rapidly transport, as well as store and slowly release TCE pure and dissolved phase for long periods of time. They also show that fate and transport of contaminants in karst environments is significantly flow dependent.

  4. Unearthing a hidden treasure: 60 years of karst research in the Far West Rand, South Africa

    Directory of Open Access Journals (Sweden)

    Aljoscha Schrader

    2015-05-01

    Full Text Available Karstified dolomitic formations situated in the Far West Rand goldfield of the Witwatersrand Basin constitute a significant groundwater resource in semi?arid South Africa and would be of strategic importance for alleviating the increasing water stress in nearby metropolitan areas. The deep?level gold mines operating below the dolomites have suffered from large volumes of dolomitic groundwater flowing into the mine voids, rendering mining both expensive and hazardous. In order to secure safe and economical mining, the overlying dolomites were dewatered. Here we review research over 60 years, conducted in three of the four major dolomitic compartments affected by dewatering. After more than six decades of research, these aquifers are arguably the most investigated karst systems in South Africa, and possibly worldwide. The data generated are, in many respects, unique, as many measurements can never be repeated, covering stochastic events such as a major water inrush into mine workings and some of the most catastrophic sinkhole developments ever recorded. Given the potential value for improving the understanding of general and local karst hydrogeology, our main goal for this paper is to alert the scientific community to the existence of this resource of mostly unpublished data and research. A no less important aim is to support a systematic collation of these studies which are in danger of being irretrievably lost as mines increasingly close down. Ecological and economic impacts of the flooding of mines in and around Johannesburg emphasise the lack of reliable historical mine data to optimally address the matter. We provide the first comprehensive, yet not exhaustive, overview on the existing studies, briefly discussing scientific content as well as obstacles for utilising the scattered, and often non?peer reviewed, information sources.

  5. Intensive exploitation of a karst aquifer leads to Cryptosporidium water supply contamination.

    Science.gov (United States)

    Khaldi, S; Ratajczak, M; Gargala, G; Fournier, M; Berthe, T; Favennec, L; Dupont, J P

    2011-04-01

    Groundwater from karst aquifers is an important source of drinking water worldwide. Outbreaks of cryptosporidiosis linked to surface water and treated public water are regularly reported. Cryptosporidium oocysts are resistant to conventional drinking water disinfectants and are a major concern for the water industry. Here, we examined conditions associated with oocyst transport along a karstic hydrosystem, and the impact of intensive exploitation on Cryptosporidium oocyst contamination of the water supply. We studied a well-characterized karstic hydrosystem composed of a sinkhole, a spring and a wellbore. Thirty-six surface water and groundwater samples were analyzed for suspended particulate matter, turbidity, electrical conductivity, and Cryptosporidium and Giardia (oo)cyst concentrations. (Oo)cysts were identified and counted by means of solid-phase cytometry (ChemScan RDI(®)), a highly sensitive method. Cryptosporidium oocysts were detected in 78% of both surface water and groundwater samples, while Giardia cysts were found in respectively 22% and 8% of surface water and groundwater samples. Mean Cryptosporidium oocyst concentrations were 29, 13 and 4/100 L at the sinkhole, spring and wellbore, respectively. Cryptosporidium oocysts were transported from the sinkhole to the spring and the wellbore, with respective release rates of 45% and 14%, suggesting that oocysts are subject to storage and remobilization in karst conduits. Principal components analysis showed that Cryptosporidium oocyst concentrations depended on variations in hydrological forcing factors. All water samples collected during intensive exploitation contained oocysts. Control of Cryptosporidium oocyst contamination during intensive exploitation is therefore necessary to ensure drinking water quality. Copyright © 2011. Published by Elsevier Ltd.

  6. Spatial resolution of transport parameters in a subtropical karst conduit system during dry and wet seasons

    Science.gov (United States)

    Ender, Anna; Goeppert, Nadine; Goldscheider, Nico

    2018-04-01

    Karst aquifers are characterized by a high degree of hydrologic variability and spatial heterogeneity of transport parameters. Tracer tests allow the quantification of these parameters, but conventional point-to-point experiments fail to capture spatiotemporal variations of flow and transport. The goal of this study was to elucidate the spatial distribution of transport parameters in a karst conduit system at different flow conditions. Therefore, six tracer tests were conducted in an active and accessible cave system in Vietnam during dry and wet seasons. Injections and monitoring were done at five sites along the flow system: a swallow hole, two sites inside the cave, and two springs draining the system. Breakthrough curves (BTCs) were modeled with CXTFIT software using the one-dimensional advection-dispersion model and the two-region nonequilibrium model. In order to obtain transport parameters in the individual sections of the system, a multi-pulse injection approach was used, which was realized by using the BTCs from one section as input functions for the next section. Major findings include: (1) In the entire system, mean flow velocities increase from 183 to 1,043 m/h with increasing discharge, while (2) the proportion of immobile fluid regions decrease; (3) the lowest dispersivity was found at intermediate discharge; (4) in the individual cave sections, flow velocities decrease along the flow direction, related to decreasing gradients, while (5) dispersivity is highest in the middle section of the cave. The obtained results provide a valuable basis for the development of an adapted water management strategy for a projected water-supply system.

  7. Heterogeneous flow in multi-layer joint networks and its influence on incipient karst generation

    Science.gov (United States)

    Wang, X.; Jourde, H.

    2017-12-01

    Various dissolution types (e.g. pipe, stripe and sheet karstic features) have been observed in fractured layered limestones. Yet, due to a large range of structural and hydraulic parameters play a role in the karstification process, the dissolution mechanism, occurring either along fractures or bedding planes, is difficult to quantify. In this study, we use numerical models to investigate the influence of these parameters on the generation of different types of incipient karst. Specifically, we focus on two parameters: the fracture intensity contrast between adjacent layers and the aperture ratio between bedding planes and joints (abed/ajoint). The DFN models were generated using a pseudo-genetic code that considers the stress shadow zone. Flow simulations were performed using a combined finite-volume finite-element simulator under practical boundary conditions. The flow channeling within the fracture networks was characterized by applying a multi-fractal technique. The rock block equivalent permeability (keff) was also calculated to quantify the change in bulk hydraulic properties when changing the selected structural and hydraulic parameters. The flow simulation results show that the abed/ajoint ratio has a first-order control on the heterogeneous distribution of flow in the multi-layer system and on the magnitude of equivalent permeability. When abed/ajoint 0.1, the bedding plane has more control and flow becomes more pervasive and uniform, and the keff is accordingly high. A simple model, accounting for the calculation of the heterogeneous distributions of Damköhler number associated with different aperture ratios, is proposed to predict what type of incipient karst tends to develop under the studied flow conditions.

  8. Impacts of management and climate change on nitrate leaching in a forested karst area.

    Science.gov (United States)

    Dirnböck, Thomas; Kobler, Johannes; Kraus, David; Grote, Rüdiger; Kiese, Ralf

    2016-01-01

    Forest management and climate change, directly or indirectly, affect drinking water resources, both in terms of quality and quantity. In this study in the Northern Limestone Alps in Austria we have chosen model calculations (LandscapeDNDC) in order to resolve the complex long-term interactions of management and climate change and their effect on nitrogen dynamics, and the consequences for nitrate leaching from forest soils into the karst groundwater. Our study highlights the dominant role of forest management in controlling nitrate leaching. Both clear-cut and shelterwood-cut disrupt the nitrogen cycle to an extent that causes peak concentrations and high fluxes into the seepage water. While this effect is well known, our modelling approach has revealed additional positive as well as negative impacts of the expected climatic changes on nitrate leaching. First, we show that peak nitrate concentrations during post-cutting periods were elevated under all climate scenarios. The maximal effects of climatic changes on nitrate concentration peaks were 20-24 mg L(-1) in 2090 with shelterwood or clear-cut management. Second, climate change significantly decreased the cumulative nitrate losses over full forest rotation periods (by 10-20%). The stronger the expected temperature increase and precipitation decrease (in summer), the lesser were the observed nitrate losses. However, mean annual seepage water nitrate concentrations and cumulative nitrate leaching were higher under continuous forest cover management than with shelterwood-cut and clear-cut systems. Watershed management can thus be adapted to climate change by either reducing peak concentrations or long-term loads of nitrate in the karst groundwater. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Dynamics Of Karstification: A Model Applied To Hydraulic Structures In Karst Terranes

    Science.gov (United States)

    Dreybrodt, W.

    1992-01-01

    To model the development of karst channels from primary fissures in limestone, a computer simulation of solutional widening of a fracture by calcite agressive water is proposed. The parameters defining the problem are the initial width a0 of the fracture, its length l, and the hydraulic gradient i driving water through it. The dissolution rates limestone determine how fast enlargement of the fractures proceeds. At a calcite concentration, c, far from equilibrium, the dissolution follows a first-order rate law, F(1)=α0(ceq-c); close to the equilibrium concentration, ceq, a slow fourth-order rate law F(4)=β0(ceq-c)4 is valid. The results show that, at the time of initiation, the water flow through the karst channels increases slowly in time until an abrupt increase occurs. After this moment of breakthrough, the channel enlarges rapidly and evenly over its entire length by first-order kinetics. Breakthrough times have been calculated for karstification under natural conditions for low hydraulic gradients as functions of a0, l, and i. Special attention is given to karstification in the vicinity of hydraulic structures where hydraulic gradients are high (>0.5) and channel lengths are below 200 m. We find that the breakthrough event will occur in less than 100 years, if: (i/l) > (5.3·10-8a0 -2.63PCO2 -0.77) where l is in m and a0 is in cm, (i/l) is given in m-1, and PCO2[atm] is the CO2 pressure of the water entering the fracture. After this event, the channels will widen to a width of about 1 cm within only 10 years, which can cause considerable leakage near or through hydraulic structures. Finally, critical values of the parameters i, l, a0, which give the conditions of failure in various types of hydraulic structures are discussed.

  10. Tile drainage as karst: Conduit flow and diffuse flow in a tile-drained watershed

    Science.gov (United States)

    Schilling, K.E.; Helmers, M.

    2008-01-01

    The similarity of tiled-drained watersheds to karst drainage basins can be used to improve understanding of watershed-scale nutrient losses from subsurface tile drainage networks. In this study, short-term variations in discharge and chemistry were examined from a tile outlet collecting subsurface tile flow from a 963 ha agricultural watershed. Study objectives were to apply analytical techniques from karst springs to tile discharge to evaluate water sources and estimate the loads of agricultural pollutants discharged from the tile with conduit, intermediate and diffuse flow regimes. A two-member mixing model using nitrate, chloride and specific conductance was used to distinguish rainwater versus groundwater inputs. Results indicated that groundwater comprised 75% of the discharge for a three-day storm period and rainwater was primarily concentrated during the hydrograph peak. A contrasting pattern of solute concentrations and export loads was observed in tile flow. During base flow periods, tile flow consisted of diffuse flow from groundwater sources and contained elevated levels of nitrate, chloride and specific conductance. During storm events, suspended solids and pollutants adhered to soil surfaces (phosphorus, ammonium and organic nitrogen) were concentrated and discharged during the rapid, conduit flow portion of the hydrograph. During a three-day period, conduit flow occurred for 5.6% of the time but accounted for 16.5% of the total flow. Nitrate and chloride were delivered primarily with diffuse flow (more than 70%), whereas 80-94% of total suspended sediment, phosphorus and ammonium were exported with conduit and intermediate flow regimes. Understanding the water sources contributing to tile drainage and the manner by which pollutant discharge occurs from these systems (conduit, intermediate or diffuse flow) may be useful for designing, implementing and evaluating non-point source reduction strategies in tile-drained landscapes. ?? 2007 Elsevier B.V. All

  11. Evolution of a Lowland Karst Landscape; A Mass-Balance Approach

    Science.gov (United States)

    Chamberlin, C.; Heffernan, J. B.; Cohen, M. J.; Quintero, C.; Pain, A.

    2016-12-01

    Karst landscapes are highly soluble, and are vulnerable to biological acid production as a major driving factor in their evolution. Big Cypress National Park (BICY) is a low-lying karst landscape in southern Florida displaying a distinctive morphology of isolated depressions likely influenced by biology. The goal of this study is to constrain timescales of landform development in BICY. This question was addressed through the construction of landscape-scale elemental budgets for both calcium and phosphorus. Precipitation and export fluxes were calculated using available chemistry and hydrology data, and stocks were calculated from a combination of existing data, field measurements, and laboratory chemical analysis. Estimates of expected mass export given no biological acid production and given an equivalent production of 100% of GPP were compared with observed rates. Current standing stocks of phosphorus are dominated by a large soil pool, and contain 500 Gg P. Inputs are largely dominated by precipitation, and 8000 years are necessary to accumulate standing stocks of phosphorus given modern fluxes. Calcium flux is vastly dominated by dissolution of the limestone bedrock, and though some calcium is retained in the soil, most is exported. Using LiDAR generated estimates of volume loss across the landscape and current export rates, an estimated 15,000 years would be necessary to create the modern landscape. Both of these estimates indicate that the BICY landscape is geologically very young. The different behaviors of these elements (calcium is largely exported, while phosphorus is largely retained) lend additional confidence to estimates of denudation rates of the landscape. These estimates can be even closer reconciled if calcium redistribution over the landscape is allowed for. This estimate is compared to the two bounding conditions for biological weathering to indicate a likely level of biological importance to landscape development in this system.

  12. Forming mechanism of the Ordovician karst carbonate reservoirs on the northern slope of central Tarim Basin

    Directory of Open Access Journals (Sweden)

    Heng Fu

    2017-07-01

    Full Text Available The Ordovician karst carbonate reservoirs on the northern slope of central Tarim Basin are important oil and gas exploration targets in the basin, but their dissolution mechanisms are in controversy. In this paper, based on the integrated study of sedimentation, sequence and reservoir, together with microscopic analysis and macroscopic seismic data analysis, the carbonate karst reservoirs in the study area were divided into three types: dissolved pore-cavity limestone reservoir, pore-cavity dolomite reservoir and fracture-cavity siliceous reservoir, and their forming mechanisms were discussed respectively. Some findings were obtained. First, dissolved pore-cavity limestone reservoirs are distributed in the upper Yingshan Fm and Yijianfang Fm of the Ordovician vertically, while pore-cavity dolomite reservoirs are mainly developed in the Penglai Fm and lower Yingshan Fm of the Ordovician with great thickness. Second, dissolved pore-cavity limestone reservoirs were formed by karstification on the third-order sequence boundary (lowstand tract, while pore-cavity dolomite reservoirs were formed by deep burial dolomitization controlled by karstification on the third-order sequence boundary, both of which are distributed in the highstand tract below the third-order sequence boundary. Third, siliceous reservoirs are developed under the control of faulting, as a result of reworking of deep hydrothermal fluids along faults to the limestone, and the siliceous reservoirs and their hydrothermal solution fracture-cavity systems are distributed near faults. It is further predicted that, in addition to the three types of reservoir above, platform-margin reef-flat reservoirs are developed in the Ordovician on the northern slope of central Tarim Basin.

  13. Analysis of water control in an underground mine under strong karst media influence (Vazante mine, Brazil)

    Science.gov (United States)

    Ninanya, Hugo; Guiguer, Nilson; Vargas, Eurípedes A.; Nascimento, Gustavo; Araujo, Edmar; Cazarin, Caroline L.

    2018-05-01

    This work presents analysis of groundwater flow conditions and groundwater control measures for Vazante underground mine located in the state of Minas Gerais, Brazil. According to field observations, groundwater flow processes in this mine are highly influenced by the presence of karst features located in the near-surface terrain next to Santa Catarina River. The karstic features, such as caves, sinkholes, dolines and conduits, have direct contact with the aquifer and tend to increase water flow into the mine. These effects are more acute in areas under the influence of groundwater-level drawdown by pumping. Numerical analyses of this condition were carried out using the computer program FEFLOW. This program represents karstic features as one-dimensional discrete flow conduits inside a three-dimensional finite element structure representing the geologic medium following a combined discrete-continuum approach for representing the karst system. These features create preferential flow paths between the river and mine; their incorporation into the model is able to more realistically represent the hydrogeological environment of the mine surroundings. In order to mitigate the water-inflow problems, impermeabilization of the river through construction of a reinforced concrete channel was incorporated in the developed hydrogeological model. Different scenarios for channelization lengths for the most critical zones along the river were studied. Obtained results were able to compare effectiveness of different river channelization scenarios. It was also possible to determine whether the use of these impermeabilization measures would be able to reduce, in large part, the elevated costs of pumping inside the mine.

  14. Chemical indicators of anthropogenic impacts in sediments of the pristine karst lakes.

    Science.gov (United States)

    Mikac, I; Fiket, Z; Terzić, S; Barešić, J; Mikac, N; Ahel, M

    2011-08-01

    The anthropogenic impact on the pristine karst lakes was investigated using combination of specific parameters, including multielemental analysis of major inorganic constituents (Al, K, Fe) and trace metals (Li, Ag, Cd, Sn, Pb, Bi, Cr, Co, Ni, Cu, Zn and Sb), polycyclic aromatic hydrocarbons (PAHs) and anionic surfactants of linear alkylbenzene sulfonate (LAS) type. The study was performed in the Plitvice Lakes National Park, situated in a sparsely populated area of the northwestern Dinarides, central Croatia. Dated cores of recent sediments from the two biggest lakes, Lake Prosce and Lake Kozjak, were analysed for the selected contaminants using highly specific methods, involving inductively coupled plasma mass spectrometry (ICP/MS), gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). The concentration of inorganic constituents reflected primarily the geological background of the area as well as geomorphological and geochemical characteristics of the Plitvice Lakes. Due to the higher terrigenous input, the concentration of all elements was significantly higher in the Lake Prosce. The concentration of toxic metals was relatively low in both lakes, except for Cd (>1 mg kg(-1)) and Pb (up to 40 mg kg(-1)). The vertical profiles of these metals suggested that elevated concentrations of Cd were of natural origin, derived from the erosion of the Jurassic dolomite bedrock, while Pb was predominately of recent anthropogenic origin. A similar distribution pattern, suggesting the same prevailing mechanism of input, was observed for pyrolytic PAHs. The characteristic diagnostic PAH ratios revealed that higher PAHs prevailingly originated from the combustion of biomass and fossil fuels. LAS, which represent highly specific indicators of untreated wastewaters, were found in rather high concentrations in the recent sediment layers (up to 4.7 mg kg(-1)), suggesting that contaminated household and hotel wastewaters reach the

  15. Karst system vadose zone hydrodynamics highlighted by an integrative geophysical and hydrogeological monitoring

    Science.gov (United States)

    Watlet, A.; Van Camp, M. J.; Francis, O.; Poulain, A.; Hallet, V.; Rochez, G.; Kaufmann, O.

    2015-12-01

    The vadose zone of karst systems plays an important role on the water dynamics. In particular, temporary perched aquifers can appear in the subsurface due to changes of climate conditions, diminished evapotranspiration and differences of porosity relative to deeper layers. It is therefore crucial, but challenging, to separate the hydrological signature of the vadose zone from the one of the saturated zone for understanding hydrological processes that occur in the vadose zone. Although many difficulties are usually encountered when studying karst environments due to their heterogeneities, cave systems offer an outstanding opportunity to investigate vadose zone from the inside with various techniques. We present results covering two years of hydrogeological and geophysical monitoring at the Rochefort Cave Laboratory (RCL), located in the Variscan fold-and-thrust belt (Belgium), a region that shows many karstic networks within Devonian limestone units. Hydrogeological data such as flows and levels monitoring or tracer tests performed in both vadose and saturated zones bring valuable information on the hydrological context of the studied area. Combining those results with geophysical measurements allows validating and imaging them with more integrative techniques. A microgravimetric monitoring involves a superconducting gravimeter continuously measuring at the surface of the RCL. Early in 2015, a second relative gravimeter was installed in the underlying cave system located 35 meters below the surface. This set up allows highlighting vadose gravity changes. These relative measurements are calibrated using an absolute gravimeter. 12 additional stations (7 at the surface, 5 in the cave) are monitored on a monthly basis by a spring gravimeter. To complete these gravimetric measurements, the site has been equipped with a permanent Electrical Resistivity Tomography (ERT) monitoring system comprising an uncommon array of surface, borehole and cave electrodes. Although such

  16. Applying a weighted random forests method to extract karst sinkholes from LiDAR data

    Science.gov (United States)

    Zhu, Junfeng; Pierskalla, William P.

    2016-02-01

    Detailed mapping of sinkholes provides critical information for mitigating sinkhole hazards and understanding groundwater and surface water interactions in karst terrains. LiDAR (Light Detection and Ranging) measures the earth's surface in high-resolution and high-density and has shown great potentials to drastically improve locating and delineating sinkholes. However, processing LiDAR data to extract sinkholes requires separating sinkholes from other depressions, which can be laborious because of the sheer number of the depressions commonly generated from LiDAR data. In this study, we applied the random forests, a machine learning method, to automatically separate sinkholes from other depressions in a karst region in central Kentucky. The sinkhole-extraction random forest was grown on a training dataset built from an area where LiDAR-derived depressions were manually classified through a visual inspection and field verification process. Based on the geometry of depressions, as well as natural and human factors related to sinkholes, 11 parameters were selected as predictive variables to form the dataset. Because the training dataset was imbalanced with the majority of depressions being non-sinkholes, a weighted random forests method was used to improve the accuracy of predicting sinkholes. The weighted random forest achieved an average accuracy of 89.95% for the training dataset, demonstrating that the random forest can be an effective sinkhole classifier. Testing of the random forest in another area, however, resulted in moderate success with an average accuracy rate of 73.96%. This study suggests that an automatic sinkhole extraction procedure like the random forest classifier can significantly reduce time and labor costs and makes its more tractable to map sinkholes using LiDAR data for large areas. However, the random forests method cannot totally replace manual procedures, such as visual inspection and field verification.

  17. Real interest parity decomposition

    Directory of Open Access Journals (Sweden)

    Alex Luiz Ferreira

    2009-09-01

    Full Text Available The aim of this paper is to investigate the general causes of real interest rate differentials (rids for a sample of emerging markets for the period of January 1996 to August 2007. To this end, two methods are applied. The first consists of breaking the variance of rids down into relative purchasing power pariety and uncovered interest rate parity and shows that inflation differentials are the main source of rids variation; while the second method breaks down the rids and nominal interest rate differentials (nids into nominal and real shocks. Bivariate autoregressive models are estimated under particular identification conditions, having been adequately treated for the identified structural breaks. Impulse response functions and error variance decomposition result in real shocks as being the likely cause of rids.O objetivo deste artigo é investigar as causas gerais dos diferenciais da taxa de juros real (rids para um conjunto de países emergentes, para o período de janeiro de 1996 a agosto de 2007. Para tanto, duas metodologias são aplicadas. A primeira consiste em decompor a variância dos rids entre a paridade do poder de compra relativa e a paridade de juros a descoberto e mostra que os diferenciais de inflação são a fonte predominante da variabilidade dos rids; a segunda decompõe os rids e os diferenciais de juros nominais (nids em choques nominais e reais. Sob certas condições de identificação, modelos autorregressivos bivariados são estimados com tratamento adequado para as quebras estruturais identificadas e as funções de resposta ao impulso e a decomposição da variância dos erros de previsão são obtidas, resultando em evidências favoráveis a que os choques reais são a causa mais provável dos rids.

  18. TESS Objects of Interest

    Science.gov (United States)

    Guerrero, Natalia; Glidden, Ana; Fausnaugh, Michael; TESS Team

    2018-01-01

    We describe the search for TESS Objects of Interest (TOIs), led by the MIT branch of the TESS Science Office (TSO). TSO has developed a tool called TESS Exoplanet Vetter (TEV) to facilitate this process. Individuals independently examine data validation products for each target and assign a category to the object: planet candidate, eclipsing binary, other astrophysical, stellar variability, or instrument noise/systematic. TEV assigns a preliminary follow-up priority designation to each object and allows for modification when final dispositions are decided on in a group setting. When all targets are vetted, TEV exports a catalogue of TOIs which is delivered to the TESS Follow-Up Observing Program (TFOP), working with ExoFOP-TESS, and made publicly available on the official TESS website and the Mikulski Archive for Space Telescopes (MAST).

  19. BANKING WITHOUT INTEREST

    Directory of Open Access Journals (Sweden)

    Jana Ilieva

    2017-06-01

    Full Text Available In recent years, there has been increased global awareness of Islamic finance. This topic is mainly opened with respect to the great financial crisis that mostly hit the banking system and the financial markets and caused many bank bankruptcies and state interventions. This paper analyzes the basic principles of Islamic banking. The absolute prohibition of receiving and giving interest (Riba and profit-and-loss sharing (PLS paradigms are elaborated in detail; they are primarily based on mudarabah (profit-sharing and musyarakah (joint venture concepts which nowadays are becoming an accepted way of doing business in several Western multinational banks. An overall comparison of the advantages of Islamic vs. conventional banking is also given. Islamic finance technology solutions have matured and they will face various challenges in the following decades, due to conventional banks offering, increasingly, Islamic products. The need for a more comprehensive environment and regulatory framework is emphasized, so that Islamic banking development can be ensured.

  20. Globalization, values, interests

    Directory of Open Access Journals (Sweden)

    Radojičić Mirjana S.

    2003-01-01

    Full Text Available The nature of the international politics, after the Cold War directed by the U.S. as the only current super-power, are considered in the text. The author’s intention is to stress the main points of divergence between moralistic-valuable rhetoric and the foreign policy practice of the U.S. In that sense, the examples of the American stand, i.e. the active treatment of the Yugoslav crisis, on the one hand, and the crisis in the Persian Gulf, on the other hand, is considered. The author’s conclusion is that the foreign policy of the only current super-power is still directed by interests rather then by values. In the concluding part, the author presents an anthropologic argument in favor of reestablishing "balance of power" as the only guarantee for peace and stability of the world.

  1. Interest Matters: The Importance of Promoting Interest in Education.

    Science.gov (United States)

    Harackiewicz, Judith M; Smith, Jessi L; Priniski, Stacy J

    2016-10-01

    Interest is a powerful motivational process that energizes learning, guides academic and career trajectories, and is essential to academic success. Interest is both a psychological state of attention and affect toward a particular object or topic, and an enduring predisposition to reengage over time. Integrating these two definitions, the four-phase model of interest development guides interventions that promote interest and capitalize on existing interests. Four interest-enhancing interventions seem useful: attention-getting settings, contexts evoking prior individual interest, problem-based learning, and enhancing utility value. Promoting interest can contribute to a more engaged, motivated, learning experience for students.

  2. Groundwater contamination and the relationship between water chemistry and biotic components in a karst system (Bihor Mountains, Romania

    Directory of Open Access Journals (Sweden)

    Laura Epure

    2014-12-01

    Full Text Available The physical and chemical characteristics, microbial contaminat ion, and meiofauna of the Ocoale-Gheţar-Dobreşti karst system (Bihor Mountains, Romania were studied in order to assess the natural water quality by an interdisciplinary study. A total of 60 water samples were collected seasonally from 7 sites. Physico-chemical results showed a typical composition of karst waters, except for one site, where Ca2+ was absent, pH was very low, and the abundance and diversity of meiofauna were highest, demonstrating life support even for the most sensitive animals. No significant chemical pollution was found, but microbial contamination occurred in all samples, according to the national water quality standards of the analyzed springs. The Canonical Correlation Analysis and the Canonical Correspondence Analysis performed showed a strong connection between pH, nitrates and faecal pollution, indicating also a direct connection between microbial contaminants and dissolved oxygen.

  3. Visualization of conduit-matrix conductivity differences in a karst aquifer using time-lapse electrical resistivity

    Science.gov (United States)

    Meyerhoff, Steven B.; Karaoulis, Marios; Fiebig, Florian; Maxwell, Reed M.; Revil, André; Martin, Jonathan B.; Graham, Wendy D.

    2012-12-01

    In the karstic upper Floridan aquifer, surface water flows into conduits of the groundwater system and may exchange with water in the aquifer matrix. This exchange has been hypothesized to occur based on differences in discharge at the Santa Fe River Sink-Rise system, north central Florida, but has yet to be visualized using any geophysical techniques. Using electrical resistivity tomography, we conducted a time-lapse study at two locations with mapped conduits connecting the Santa Fe River Sink to the Santa Fe River Rise to study changes of electrical conductivity during times of varying discharge over a six-week period. Our results show conductivity differences between matrix, conduit changes in resistivity occurring through time at the locations of mapped karst conduits, and changes in electrical conductivity during rainfall infiltration. These observations provide insight into time scales and matrix conduit conductivity differences, illustrating how surface water flow recharged to conduits may flow in a groundwater system in a karst aquifer.

  4. Subsidence hazards connected to quarrying activities in a karst area: the case of the Moncalvo sinkhole event (Piedmont, NW Italy

    Directory of Open Access Journals (Sweden)

    Bonetto, Sabrina

    2008-09-01

    Full Text Available Gypsum is an important raw material for constructions and other industrial sectors. In Piedmont (NW Italy, main gypsum bodies are located in the Monferrato area, where large open pits and underground quarries are present. The gypsum-bearing formation outcropping in this area shows typical geological, structural, and hydrogeological features, which affect the quarrying and the related interaction with natural phenomena, human activities, and land use. In particular, gypsum karst has considerable influence on mining operations, as well as mining operations can produce strong impact on gypsum karst. In Monferrato, a specific case of interaction between the quarrying activity and geological, hydrogeological, and territorial setting is represented by the event of water inrush that happened in the Moncalvo underground quarry in association with the development of a surface sinkhole phenomenon.

  5. The influence of conceptual model uncertainty on management decisions for a groundwater-dependent ecosystem in karst

    DEFF Research Database (Denmark)

    Gondwe, Bibi Ruth Neuman; Merediz-Alonso, Gonzalo; Bauer-Gottwein, Peter

    2011-01-01

    abstractions and pollution threatens the fresh water resource, and consequently the ecosystem integrity of both Sian Ka’an and the adjacent coastal environment. Seven different catchment-scale conceptual models were implemented in a distributed hydrological modelling approach. Equivalent porous medium...... to preserve water resources and maintain ecosystem services. Multiple Model Simulation highlights the impact of model structure uncertainty on management decisions using several plausible conceptual models. Multiple Model Simulation was used for this purpose on the Yucatan Peninsula, which is one of the world......Groundwater management in karst is often based on limited hydrologic understanding of the aquifer. The geologic heterogeneities controlling the water flow are often insufficiently mapped. As karst aquifers are very vulnerable to pollution, groundwater protection and land use management are crucial...

  6. Hydrologic Conditions that Influence Streamflow Losses in a Karst Region of the Upper Peace River, Polk County, Florida

    Science.gov (United States)

    Metz, P.A.; Lewelling, B.R.

    2009-01-01

    The upper Peace River from Bartow to Fort Meade, Florida, is described as a groundwater recharge are