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Sample records for lake biwa drainage

  1. Constraint on radiocarbon age correction in Lake Biwa environment from the middle to late Holocene

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    Miyata, Y., E-mail: miyata@nendai.nagoya-u.ac.jp [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan); National Museum of Japanese History, Sakura 285-8502 (Japan); Minami, M. [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan); Onbe, S. [National Museum of Japanese History, Sakura 285-8502 (Japan); Archaeological Heritage Management Office, Tokushima University, Tokushima 770-8503 (Japan); Sakamoto, M. [National Museum of Japanese History, Sakura 285-8502 (Japan); Nakamura, T. [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan); Imamura, M. [National Museum of Japanese History, Sakura 285-8502 (Japan)

    2013-01-15

    Using data from previous studies and newly collected data, we compared the measured radiocarbon ages of molluscan shells, common reed (Phragmites australis) and pine needles (Pinus thunbergii) collected in 1966, 1970, 1990 and 2008 at Lake Biwa in Japan, and of archaeological samples, to examine radiocarbon reservoir effects at Lake Biwa. We also tested for differences in the radiocarbon reservoir effect between species and locations in the lake. The effects of nuclear bomb tests conducted in the 1950s and 1960s are clear, the offset between atmospheric {sup 14}C and the Lake Biwa freshwater {sup 14}C is larger for this period because the atmospheric {sup 14}C is so high. The semiclosed Lake Biwa system is in dynamic equilibrium with the atmosphere, resulting in the {sup 14}C content of the water following the changes in atmospheric {sup 14}C caused by nuclear testing. The shells collected after 1990 had radiocarbon ages that were 330-450 {sup 14}C years older than those of the coeval atmosphere. The apparent differences in radiocarbon age (about 300 {sup 14}C years) between shell fossils and wood samples excavated from the same layer of the submerged Awazu shell midden at Lake Biwa suggest that the radiocarbon reservoir effect also existed in the middle Holocene (the Middle Jomon period, about 5000 years ago). Because the present-day average residence time of Lake Biwa water is 3-6 years, its direct influence on the radiocarbon reservoir effect is small, which suggests that old carbon has been supplied into Lake Biwa.

  2. Morphology and gene sequence of Levicoleps biwae n. gen., n. sp. (Ciliophora, Prostomatida), a proposed endemic from the ancient Lake Biwa, Japan.

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    Foissner, Wilhelm; Kusuoka, Yasushi; Shimano, Satoshi

    2008-01-01

    Levicoleps biwae n. gen., n. sp. was discovered in organic mud on the shore of Lake Biwa, Japan. Its morphology and small subunit rRNA gene sequence were studied with standard methods. Further, we established a terminology for the colepid armour and selected four features for genus recognition: the number of armour tiers, the structure of the tier plates, the presence/absence of armour spines, and the number of adoral organelles (three or five). The Japanese colepid, a barrel-shaped ciliate with an average size of 75 x 45 microm, has six armour tiers and hirtus-type tier plates, but lacks armour spines, both in the environment and in laboratory culture. Thus, it is considered to represent a new genus. This rank is supported by the considerable genetic distance (7%) from the common Coleps hirtus. Although L. biwae looks quite similar to C. hirtus in vivo, it is very likely most closely related to Coleps amphacanthus, a species with conspicuous armour spines, as indicated by body size, the number of ciliary rows and, especially, the multiple caudal cilia. Lake Biwa is about four million years old and inhabited by many endemic organisms, ranging from algae to large fish. Thus, we suspect that L. biwae is restricted to Lake Biwa or, at least, to Asia. Based on literature data and the generic features established, we also propose the new genus Reticoleps for Coleps remanei Kahl, 1933, and resurrect the genus Pinacocoleps Diesing, 1865 to include Coleps incurvus Ehrenberg, 1833, Coleps pulcher Spiegel, 1926, Coleps tessalatus Kahl, 1930 and, probably, Baikalocoleps quadratus Obolkina, 1995a. Nine colepid genera are diagnosed and dichotomously keyed.

  3. Morphology and Gene Sequence of Levicoleps biwae n. gen., n. sp. (Ciliophora, Prostomatida), a Proposed Endemic from the Ancient Lake Biwa, Japan

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    FOISSNER, WILHELM; KUSUOKA, YASUSHI; SHIMANO, SATOSHI

    2010-01-01

    Levicoleps biwae n. gen., n. sp. was discovered in organic mud on the shore of Lake Biwa, Japan. Its morphology and small subunit rRNA gene sequence were studied with standard methods. Further, we established a terminology for the colepid armour and selected four features for genus recognition: the number of armour tiers, the structure of the tier plates, the presence/absence of armour spines, and the number of adoral organelles (three or five). The Japanese colepid, a barrel-shaped ciliate with an average size of 75 × 45 μm, has six armour tiers and hirtus-type tier plates, but lacks armour spines, both in the environment and in laboratory culture. Thus, it is considered to represent a new genus. This rank is supported by the considerable genetic distance (7%) from the common Coleps hirtus. Although L. biwae looks quite similar to C. hirtus in vivo, it is very likely most closely related to Coleps amphacanthus, a species with conspicuous armour spines, as indicated by body size, the number of ciliary rows and, especially, the multiple caudal cilia. Lake Biwa is about four million years old and inhabited by many endemic organisms, ranging from algae to large fish. Thus, we suspect that L. biwae is restricted to Lake Biwa or, at least, to Asia. Based on literature data and the generic features established, we also propose the new genus Reticoleps for Coleps remanei Kahl, 1933, and resurrect the genus Pinacocoleps Diesing, 1865 to include Coleps incurvus Ehrenberg, 1833, Coleps pulcher Spiegel, 1926, Coleps tessalatus Kahl, 1930 and, probably, Baikalocoleps quadratus Obolkina, 1995a. Nine colepid genera are diagnosed and dichotomously keyed. PMID:18460156

  4. Morphology and Gene Sequence of Levicoleps biwae n. gen., n. sp. (Ciliophora, Prostomatida), a Proposed Endemic from the Ancient Lake Biwa, Japan

    OpenAIRE

    FOISSNER, WILHELM; KUSUOKA, YASUSHI; SHIMANO, SATOSHI

    2008-01-01

    Levicoleps biwae n. gen., n. sp. was discovered in organic mud on the shore of Lake Biwa, Japan. Its morphology and small subunit rRNA gene sequence were studied with standard methods. Further, we established a terminology for the colepid armour and selected four features for genus recognition: the number of armour tiers, the structure of the tier plates, the presence/absence of armour spines, and the number of adoral organelles (three or five). The Japanese colepid, a barrel-shaped ciliate w...

  5. A STUDY OF RECOVERING A REED ECOSYSTEM USING POROUS CONCRETE IN THE LAKE BIWA SHORE

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    Takeda, Naho; Kato, Hayato; Okamoto, Takahisa; Kojima, Takayuki

    In this study, reed planting tests were carried out at the Biyo-center, an experiment station on the Lake Biwa shore, in order to evaluate the feasibility of a planting method with porous concrete (PoC method). Reed planting tests with coconut-fiber mats (mat method), which were generally used around Lake Biwa, were simultaneously carried out to compare with the PoC method. The reeds planted by the PoC method grew better than the ones planted by the mat method, and the number of reeds which were washed away by waves was smaller than that planted by the mat method. The result of the observation of reeds planted in the PoC showed plant maturation, and reeds could ta ke root into the PoC without interference with the voids of the PoC. As a result, it was shown that the reed planting tests with the PoC method was simple and effective, so it would become in harmony with the environment around Lake Biwa.

  6. Water pH and temperature in Lake Biwa from MBT'/CBT indices during the last 280 000 years

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    Ajioka, T.; Yamamoto, M.; Takemura, K.; Hayashida, A.; Kitagawa, H.

    2014-10-01

    We generated a 280 000 yr record of water pH and temperature in Lake Biwa, central Japan, by analysing the methylation index (MBT') and cyclisation ratio (CBT) of branched tetraethers in sediments from piston and borehole cores. Our aim was to understand the responses of precipitation and air temperature in central Japan to the East Asian monsoon variability on orbital timescales. Because the water pH in Lake Biwa is determined by phosphorus and alkali cation inputs, the record of water pH should indicate the changes in precipitation and temperature in central Japan. Comparison with a pollen assemblage in a Lake Biwa core suggests that lake water pH was determined by summer temperature in the low-eccentricity period before 55 ka, while it was determined by summer precipitation in the high-eccentricity period after 55 ka. From 130 to 55 ka, the variation in lake pH (summer precipitation) lagged behind that in summer temperature by several thousand years. This perspective is consistent with the conclusions of previous studies (Igarashi and Oba, 2006; Yamamoto, 2009), in that the temperature variation preceded the precipitation variation in central Japan.

  7. Eutrophication and warming effects on long-term variation of zooplankton in Lake Biwa

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    C. H. Hsieh

    2011-05-01

    Full Text Available We compiled and analyzed long-term (1961–2005 zooplankton community data in response to environmental variations in Lake Biwa. Environmental data indicate that Lake Biwa had experienced eutrophication (according to the total phosphorus concentration in the late 1960s and recovered to a normal trophic status around 1985, and then has exhibited warming since 1990. Total zooplankton abundance showed a significant correlation with total phytoplankton biomass. Following a classic pattern, the cladoceran/calanoid and cyclopoid/calanoid abundance ratio was related positively to eutrophication. The zooplankton community exhibited a significant response to the boom and bust of phytoplankton biomass as a consequence of eutrophication-reoligotriphication and warming. Moreover, our analyses suggest that the Lake Biwa ecosystem exhibited a hierarchical response across trophic levels; that is, higher trophic levels may show a more delayed response or no response to eutrophication than lower ones.

    We tested the hypothesis that the phytoplankton community can better explain the variation of the zooplankton community than bulk environmental variables, considering that the phytoplankton community may directly affect the zooplankton succession through predator-prey interactions. Using a variance partition approach, however, we did not find strong evidence to support this hypothesis. We further aggregated zooplankton according to their feeding types (herbivorous, carnivorous, omnivorous, and parasitic and taxonomic groups, and analyzed the aggregated data. While the pattern remains similar, the results are less clear comparing the results based on finely resolved data. Our research suggests that zooplankton can be bio-indicators of environmental changes; however, the efficacy depends on data resolution.

  8. Effect of agriculture on water quality of Lake Biwa tributaries, Japan

    International Nuclear Information System (INIS)

    Nakano, Takanori; Tayasu, Ichiro; Yamada, Yoshihiro; Hosono, Takahiro; Igeta, Akitake; Hyodo, Fujio; Ando, Atsushi; Saitoh, Yu; Tanaka, Takuya; Wada, Eitaro; Yachi, Shigeo

    2008-01-01

    We investigated the effects of natural environments and human activity on Lake Biwa, central Japan. We determined the concentrations of 19 elements and the compositions of stable S and Sr isotopes in the main tributaries of the lake and compared them with the corresponding values obtained from the lake water during the circulation period. Results of a principal component analysis indicated that the components dissolved in the lower reaches of the tributaries can be divided into group 1 (HCO 3 , SO 4 , NO 3 , Ca, Mg, Sr) and group 2 components (Cl, Br, Na, K, Ba, Rb, Cs). The concentrations of group 1 components were high in the rivers of the southern area, which is urbanized and densely populated, and the eastern area, which consists of plains where agriculture predominates, compared with the rivers of the northern and western areas, which are mostly mountainous and sparsely populated. The concentrations of group 2 components tended to be high in the river water of industrial areas. The δ 34 S values of SO 4 in the river water converged to 0 ± 2 per mille as the SO 4 concentration increased and, excluding the areas where limestone is extensively distributed, as the HCO 3 concentration increased. In particular, both the δ 34 S values (0 ± 2 per mille ) and the 87 Sr/ 86 Sr ratios (0.7117 ± 0.0005) fell within narrow ranges in the small and medium rivers of the eastern plain area, where rice is widely grown. These values agreed respectively with the δ 34 S values of the fertilizers used in the Lake Biwa basin and the soil-exchangeable 87 Sr/ 86 Sr in the eastern plain. The characteristics of water quality in the small and medium rivers of the eastern area can be explained by a model in which sulfuric, nitric, and bicarbonic acids generated by the decomposition of agricultural fertilizer and paddy rice selectively leached out alkaline-earth elements adsorbed on the soil and sediments of the plain or dissolved calcium carbonate enriched with Mg and Sr. Compared

  9. Water resources management in the urban agglomeration of the Lake Biwa region, Japan: An ecosystem services-based sustainability assessment.

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    Chen, Xiaochen; Chen, Yuqing; Shimizu, Toshiyuki; Niu, Jia; Nakagami, Ken'ichi; Qian, Xuepeng; Jia, Baoju; Nakajima, Jun; Han, Ji; Li, Jianhua

    2017-05-15

    An innovative ecosystem services-based sustainability assessment was conducted in the important urban agglomeration of the Lake Biwa region, Japan, covering the time period from 1950 to 2014. A 22-indicator system was established that was based on the major ecosystem services of Lake Biwa and its water courses, i.e., provisioning services regarding aquatic products and water; regulating services regarding floods and water quality; cultural services regarding recreation and tourism, scientific research, and environmental education; and supporting services regarding biodiversity. First, changes in the eight ecosystem services were discussed together with the considerable experience and difficult lessons that can be drawn from the development trajectory. Next, with the indicators rearranged according to sustainability principles, the regional sustainability over the past six-plus decades was assessed. In general, this urban agglomeration has been progressing in terms of its sustainability, although economic and social development was achieved at the cost of environmental degradation in the past, and the current economic downturn is hurting the balanced development and integrated benefits. The results lead directly to recommendations for regional development, especially in terms of economic rejuvenation, from the perspective of improving management of Lake Biwa's water resources. Moreover, the relevant knowledge is educational and inspirational for other places in the world that are facing similar development issues. For example, the effective and even pioneering countermeasures that have been taken against environmental degradation, as well as the participation and collaboration of multiple stakeholders, could be useful as a model. Moreover, the study invites increased understanding of ecosystem vulnerability to anthropogenic devastation and emphasizes the priority of precautionary measures over countermeasures in the context of holistic urban planning and sustainable

  10. Arsenic and Mn levels in Isaza (Gymnogobius isaza) during the mass mortality event in Lake Biwa, Japan

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    Hirata, Sawako Horai; Hayase, Daisuke; Eguchi, Akifumi; Itai, Takaaki; Nomiyama, Kei; Isobe, Tomohiko; Agusa, Tetsuro [Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan); Ishikawa, Toshiyuki [Department of Environmental Education, Faculty of Education, Shiga University, 2-5-1 Hiratsu, Otsu, Shiga 520-0862 (Japan); Kumagai, Michio [Lake Biwa Environmental Research Institute, 5-34 Yanagasaki, Otsu, Shiga 520-0022 (Japan); Tanabe, Shinsuke, E-mail: shinsuke@agr.ehime-u.ac.jp [Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan)

    2011-10-15

    The present study measured the concentrations of 25 elements (Li, Mg, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb and Bi) in the whole body of Isaza which is an endemic fish species to Lake Biwa, Japan, and compared the values in the specimens from the mass mortality Isaza (MMI) and normal fresh Isaza (NFI). The mean levels of Mn and total As (T-As) were relatively higher in MMI than in NFI. In the T-As, highly toxic inorganic As was detected in MMI. Moreover we found Mn and As concentrations in surface sediment were extremely high and temporally increased. From all these results, we could infer that the dissolution of Mn and As from surface sediment of Lake Biwa might have been one of the cause for the mass mortality of Isaza. - Highlights: > Mn and As levels were significantly higher in MMI than in NFI. > The number of chemical species of As detected from MMI was less than that from NFI. > Mn and As levels were highest in surface sediment, and sharply decreased with depth. > Mn and As levels in surface sediment temporally increased. - As and Mn levels in dead Isaza caused by mass mortality.

  11. Paleoclimatic features in Central Japan based on the stable isotope compositions of Lake Biwa sediments and speleothems

    International Nuclear Information System (INIS)

    Nakai, Nobuyuki; Shirai, Yasutoshi

    1978-01-01

    In this paper, the climatic fluctuation of Japanese Island in the past deduced from the carbon isotope study of Lake Biwa sediments is discussed in connection with the vertical profile of fossil diatom numbers, climate estimated by palynological studies, and paleogeomagnetic polarity change for the same core samples. In addition to the climatic studies that have used the Lake sediments, the climatic change measured in detail by O 18 /O 16 ratios of speleothem CaCO 3 is reported for the past 37 x 10 3 years. Sediment samples for C 13 /C 12 analyses were taken at intervals of 5 m from the cored column of 200 m length. Stalactite and flowstone samples were collected from Otaki Cave, Gifu Prefecture, near Lake Biwa. The isotopic data for both carbon and oxygen are presented as per mil deviation from the PDB and SMOW standards, respectively. The Δ C 13 values of organic C are plotted in relation to the number of total diatom cells. The figure shows no correlation between them. The Δ C 13 values of sedimentary organic C and the past productivity of the lake have different linear relation in each different period. The present authors tried to calculate directly the deposition temperature by a method different from Hendy's. The Δ O 18 values of the water passing through the speleothem surface in the past are determined by those of rain water in the region. The calculated temperatures range from 10.6 to 15.0 deg. C. By connecting the results obtained from two flowstones and a stalactite, a paleotemperature curve can be drawn for the last 37 x 10 3 years. (Kato, T

  12. Water pH and temperature in Lake Biwa from MBT'/CBT indices during the last 282 000 years

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    Ajioka, T.; Yamamoto, M.; Takemura, K.; Hayashida, A.

    2014-03-01

    We generated a 282 000-year record of water pH and temperature in Lake Biwa, central Japan, by analysing the methylation index (MBT') and cyclisation ratio (CBT) of branched tetraethers in sediments from piston and borehole cores to understand the responses of precipitation and air temperature in central Japan to the East Asian monsoon variability on the orbital timescale. Because water pH in Lake Biwa is determined by phosphorus input driven by precipitation, the record of water pH should indicate changes in summer precipitation in central Japan. The estimated pH showed significant periodicity at 19 and 23 ka (precession) and at 41 ka (obliquity). The variation in the estimated pH agrees with variation in the pollen temperature index. This indicates synchronous variation in summer air temperature and precipitation in central Japan, which contradicts the conclusions of previous studies. The variation in estimated pH was also synchronous with the variation of oxygen isotopes in stalagmites in China, suggesting that East Asian summer monsoon precipitation was governed by Northern Hemisphere summer insolation on orbital timescales. However, the estimated winter temperatures were higher during interglacials and lower during glacials, showing an eccentricity cycle. This suggests that the temperature variation reflected winter monsoon variability.

  13. Modes of supraglacial lake drainage and dynamic ice sheet response

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    Das, S. B.; Behn, M. D.; Joughin, I. R.

    2011-12-01

    We investigate modes of supraglacial lake drainage using geophysical, ground, and remote sensing observations over the western margin of the Greenland ice sheet. Lakes exhibit a characteristic life cycle defined by a pre-drainage, drainage, and post-drainage phase. In the pre-drainage phase winter snow fills pre-existing cracks and stream channels, efficiently blocking past drainage conduits. As temperatures increase in the spring, surface melting commences, initially saturating the snow pack and subsequently forming a surface network of streams that fills the lake basins. Basins continue to fill until lake drainage commences, which for individual lakes occurs at different times depending on the previous winter snow accumulation and summer temperatures. Three styles of drainage behavior have been observed: (1) no drainage, (2) slow drainage over the side into an adjacent pre-existing crack, and (3) rapid drainage through a new crack formed beneath the lake basin. Moreover, from year-to-year individual lakes exhibit different drainage behaviors. Lakes that drain slowly often utilize the same outflow channel for multiple years, creating dramatic canyons in the ice. Ultimately, these surface channels are advected out of the lake basin and a new channel forms. In the post-drainage phase, melt water continues to access the bed typically through a small conduit (e.g. moulin) formed near a local topographic minimum along the main drainage crack, draining the lake catchment throughout the remainder of the melt season. This melt water input to the bed leads to continued basal lubrication and enhanced ice flow compared to background velocities. Lakes that do not completely drain freeze over to form a surface ice layer that persists into the following year. Our results show that supraglacial lakes show a spectrum of drainage behaviors and that these styles of drainage lead to varying rates and timing of surface meltwater delivery to the bed resulting in different dynamic ice

  14. Observing a catastrophic thermokarst lake drainage in northern Alaska

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    Jones, Benjamin M.; Arp, Christopher D.

    2015-01-01

    The formation and drainage of thermokarst lakes have reshaped ice-rich permafrost lowlands in the Arctic throughout the Holocene. North of Teshekpuk Lake, on the Arctic Coastal Plain of northern Alaska, thermokarst lakes presently occupy 22.5% of the landscape, and drained thermokarst lake basins occupy 61.8%. Analysis of remotely sensed imagery indicates that nine lakes (>10 ha) have drained in the 1,750 km2 study area between 1955 and 2014. The most recent lake drainage was observed using in situ data loggers providing information on the duration and magnitude of the event, and a nearby weather station provided information on the environmental conditions preceding the lake drainage. Lake 195 (L195), an 80 ha thermokarst lake with an estimated water volume of ~872,000 m3, catastrophically drained on 05 July 2014. Abundant winter snowfall and heavy early summer precipitation resulted in elevated lake water levels that likely promoted bank overtopping, thermo-erosion along an ice-wedge network, and formation of a 9 m wide, 2 m deep, and 70 m long drainage gully. The lake emptied in 36 hours, with 75% of the water volume loss occurring in the first ten hours. The observed peak discharge of the resultant flood was 25 m3/s, which is similar to that in northern Alaska river basins whose areas are more than two orders of magnitude larger. Our findings support the catastrophic nature of sudden lake drainage events and the mechanistic hypotheses developed by J. Ross Mackay.

  15. Modeling Antarctic Subglacial Lake Filling and Drainage Cycles

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    Dow, Christine F.; Werder, Mauro A.; Nowicki, Sophie; Walker, Ryan T.

    2016-01-01

    The growth and drainage of active subglacial lakes in Antarctica has previously been inferred from analysis of ice surface altimetry data. We use a subglacial hydrology model applied to a synthetic Antarctic ice stream to examine internal controls on the filling and drainage of subglacial lakes. Our model outputs suggest that the highly constricted subglacial environment of our idealized ice stream, combined with relatively high rates of water flow funneled from a large catchment, can combine to create a system exhibiting slow-moving pressure waves. Over a period of years, the accumulation of water in the ice stream onset region results in a buildup of pressure creating temporary channels, which then evacuate the excess water. This increased flux of water beneath the ice stream drives lake growth. As the water body builds up, it steepens the hydraulic gradient out of the overdeepened lake basin and allows greater flux. Eventually this flux is large enough to melt channels that cause the lake to drain. Lake drainage also depends on the internal hydrological development in the wider system and therefore does not directly correspond to a particular water volume or depth. This creates a highly temporally and spatially variable system, which is of interest for assessing the importance of subglacial lakes in ice stream hydrology and dynamics.

  16. Isolation and characterization of a virus (CvV-BW1 that infects symbiotic algae of Paramecium bursaria in Lake Biwa, Japan

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    Kasahara Masahiro

    2010-09-01

    Full Text Available Abstract Background We performed an environmental study of viruses infecting the symbiotic single-celled algae of Paramecium bursaria (Paramecium bursaria Chlorella virus, PBCV in Lake Biwa, the largest lake in Japan. The viruses detected were all Chlorella variabilis virus (CvV = NC64A virus. One of them, designated CvV-BW1, was subjected to further characterization. Results CvV-BW1 formed small plaques and had a linear DNA genome of 370 kb, as judged by pulsed-field gel electrophoresis. Restriction analysis indicated that CvV-BW1 DNA belongs to group H, one of the most resistant groups among CvV DNAs. Based on a phylogenetic tree constructed using the dnapol gene, CvV was classified into two clades, A and B. CvV-BW1 belonged to clade B, in contrast to all previously identified virus strains of group H that belonged to clade A. Conclusions We conclude that CvV-BW1 composes a distinct species within C. variabilis virus.

  17. Ice-Dammed Lake Drainage Evolution at Russell Glacier, West Greenland

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    Jonathan L. Carrivick

    2017-11-01

    Full Text Available KEY POINTS/HIGHLIGHTSTwo rapid ice-dammed lake drainage events gauged and ice dam geometry measured.A melt enlargement model is developed to examine the evolution of drainage mechanism(s.Lake temperature dominated conduit melt enlargement and we hypothesize a flotation trigger.Glaciological and hydraulic factors that control the timing and mechanisms of glacier lake outburst floods (GLOFs remain poorly understood. This study used measurements of lake level at 15 min intervals and known lake bathymetry to calculate lake outflow during two GLOF events from the northern margin of Russell Glacier, west Greenland. We used measured ice surface elevation, interpolated subglacial topography and likely conduit geometry to inform a melt enlargement model of the outburst evolution. The model was tuned to best-fit the hydrograph rising limb and timing of peak discharge in both events; it achieved Mean Absolute Errors of <5%. About one third of the way through the rising limb, conduit melt enlargement became the dominant drainage mechanism. Lake water temperature, which strongly governed the enlargement rate, preconditioned the high peak discharge and short duration of these floods. We hypothesize that both GLOFs were triggered by ice dam flotation, and localized hydraulic jacking sustained most of their early-stage outflow, explaining the particularly rapid water egress in comparison to that recorded at other ice-marginal lakes. As ice overburden pressure relative to lake water hydraulic head diminished, flow became confined to a subglacial conduit. This study has emphasized the inter-play between ice dam thickness and lake level, drainage timing, lake water temperature and consequently rising stage lake outflow and flood evolution.

  18. Drainage of the ice-dammed Lake Tinninilik, West Greenland; implication on bedrock uplift

    DEFF Research Database (Denmark)

    Kjeldsen, Kristian Kjellerup; Khan, Shfaqat Abbas; Bjørk, Anders Anker

    Drainage of ice-dammed lakes is regularly observed along the margin of the Greenland Ice Sheet. However, the speed of the drainage events and implications can vary depending on the size of the lakes and the local settings. Here, we assess the drainage pattern of Lake Tinninilik, dammed...

  19. Modeling of subglacial hydrological development following rapid supraglacial lake drainage

    OpenAIRE

    Dow, C F; Kulessa, B; Rutt, I C; Tsai, V C; Pimentel, S; Doyle, S H; van As, D; Lindb?ck, K; Pettersson, R; Jones, G A; Hubbard, A

    2015-01-01

    The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and exa...

  20. Drainage of ice-dammed lakes and glacier retreat - a link

    DEFF Research Database (Denmark)

    Kjeldsen, Kristian Kjellerup; Kjaer, K. H.; Rysgaard, Søren

    2011-01-01

    surface freshwater run-off is found in the top of the water column in the fjord while sub-glacial meltwater is entrained deeper in the water column. The latter is highly important as this colder buoyant freshwater is pushed to the water surface followed by a compensating deeper landward current bringing...... in the fjord. The large quantity of buoyant freshwater changed the osmotic pressure and pushed redfish to the water surface causing them to die from divers disease. Further investigation suggested that three ice-dammed lakes adjacent to the Narssap Sermia glacier had drained within the previous year. Analysis......-30 times the volume of an ice-dammed lake prior to drainage. The warm water influx in turn causes the glacier to retreat and to gradually become thinner which feeds back to an increase in drainage events of ice-dammed lakes over time. On a larger scale the feedback mechanism between the drainage of lakes...

  1. Properties of the subglacial till inferred from supraglacial lake drainage

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    Neufeld, J. A.; Hewitt, D.

    2017-12-01

    The buildup and drainage of supraglacial lakes along the margins of the Greenland ice sheet has been previously observed using detailed GPS campaigns which show that rapid drainage events are often preceded by localised, transient uplift followed by rapid, and much broader scale, uplift and flexure associated with the main drainage event [1,2]. Previous models of these events have focused on fracturing during rapid lake drainage from an impermeable bedrock [3] or a thin subglacial film [4]. We present a new model of supraglacial drainage that couples the water flux from rapid lake drainage events to a simplified model of the pore-pressure in a porous, subglacial till along with a simplified model of the flexure of glacial ice. Using a hybrid mathematical model we explore the internal transitions between turbulent and laminar flow throughout the evolving subglacial cavity and porous till. The model predicts that an initially small water flux may locally increase pore-pressure in the till leading to uplift and a local divergence in the ice velocity that may ultimately be responsible for large hydro-fracturing and full-scale drainage events. Furthermore, we find that during rapid drainage while the presence of a porous, subglacial till is crucial for propagation, the manner of spreading is remarkably insensitive to the properties of the subglacial till. This is in stark contrast to the post-drainage relaxation of the pore pressure, and hence sliding velocity, which is highly sensitive to the permeability, compressibility and thickness of subglacial till. We use our model, and the inferred sensitivity to the properties of the subglacial till after the main drainage event, to infer the properties of the subglacial till. The results suggest that a detailed interpretation of supraglacial lake drainage may provide important insights into the hydrology of the subglacial till along the margins of the Greenland ice sheet, and the coupling of pore pressure in subglacial till

  2. Effect of eutrophication on the distribution of arsenic species in eutrophic and mesotrophic lakes

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, H. [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192 (Japan)], E-mail: hhiroshi@t.kanazawa-u.ac.jp; Rahman, M. Azizur; Matsuda, T.; Kitahara, T.; Maki, T.; Ueda, K. [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192 (Japan)

    2009-02-01

    Effects of eutrophication on arsenic speciation were studied in eutrophic Lake Kiba and mesotrophic Lake Biwa, Japan. By combining hydride generation atomic absorption spectrometry with ultraviolet irradiation, inorganic, methyl and ultraviolet-labile fractions of arsenic were determined. In both Lakes, inorganic species (As(V + III)) dominated over other forms of arsenic all the year round. Most of methylarsenic fraction was dimethylarsinic acid (DMAA), and the concentration of monomethylarsonic acid (MMAA) was below the detection limit. Measurements of size-fractioned arsenic concentrations in water column indicate that most of the DMAA was distributed in truly dissolved fraction (< 10 kDa), while ultraviolet-labile fractions were distributed in particulate (> 0.45 {mu}m) and colloidal (10 kDa-0.45 {mu}m) fractions. Arsenic speciation in eutrophic Lake Kiba fluctuated greatly with season. The ultraviolet-labile fractions were observed with the increase of DMAA from May to October, and they disappeared with the decrease of DMAA in January. In mesotrophic Lake Biwa, the ultraviolet-labile fractions of arsenic were not influenced as much as those in eutrophic Lake Kiba. On the other hand DMAA concentration was higher in Lake Biwa compared to that in Lake Kiba. The results suggest that the biosynthesis of complex organoarsenicals was enhanced by eutrophication, and the arsenic speciation would be influenced by the balance of biological processes in natural waters.

  3. Ice dynamic response to two modes of surface lake drainage on the Greenland ice sheet

    International Nuclear Information System (INIS)

    Tedesco, Marco; Alexander, Patrick; Willis, Ian C; Banwell, Alison F; Arnold, Neil S; Hoffman, Matthew J

    2013-01-01

    Supraglacial lake drainage on the Greenland ice sheet opens surface-to-bed connections, reduces basal friction, and temporarily increases ice flow velocities by up to an order of magnitude. Existing field-based observations of lake drainages and their impact on ice dynamics are limited, and focus on one specific draining mechanism. Here, we report and analyse global positioning system measurements of ice velocity and elevation made at five locations surrounding two lakes that drained by different mechanisms and produced different dynamic responses. For the lake that drained slowly (>24 h) by overtopping its basin, delivering water via a channel to a pre-existing moulin, speedup and uplift were less than half those associated with a lake that drained rapidly (∼2 h) through hydrofracturing and the creation of new moulins in the lake bottom. Our results suggest that the mode and associated rate of lake drainage govern the impact on ice dynamics. (letter)

  4. Lasting Effects of Glacial Lake Outburst Floods on Subglacial Drainage Networks

    Science.gov (United States)

    Robbins, M.; Hendy, I. L.; Bassis, J. N.; Aciego, S.; Stevenson, E. I.

    2017-12-01

    Supraglacial lakes forming in the ablation zone around the Greenland Ice Sheet will likely migrate toward higher elevations as polar temperatures rise through the 21st century. Present understanding of lake drainage shows it can temporarily enhance ice sheet motion, but other possible effects and interactions - especially with older pre-existing subglacial reservoirs - remain unexamined. Here we investigate possible enduring effects of the record high 2012 melt year on the en/subglacial hydrologic network, how this network responds to immediate high fluxes of water from floods, and how these phenomena might connect to previously isolated subglacial pools. Lake Hullet is a large ice dammed lake situated in south Greenland 22km up-ice from where Kiattuut Sermiat (KS) branches from a larger outlet glacier. Lake Hullet rests on bedrock and is contained by a bedrock ridge. It drains roughly annually through Lake Hullet's hydrologic network in a glacial lake outburst flood (GLOF) when water level rises such that it can flow over the obstructive ridge. Subglacial water samples collected from the toe of KS in July 2013 pre-flood were dated using U isotopes with 222Rn concentrations as well as noble gas ratios. These two independent methods reveal an exceedingly old water age of > 1000 years, indicating existence of isolated enduring subglacial meltwater pool(s). A comparison field study at the KS toe in August and September 2015 re-examined glacial hydrochemistry in a time series. 2015 222Rn concentrations are lower than 2013 values, suggesting less water-rock interaction, a reduction in residence time, and a proximal meltwater source. Increased water volume from the record high 2012 melt year may have enlarged the existing en/subglacial drainage network further into the ice sheet releasing meltwater with longer residence times beneath the ice, with effects lasting into subsequent melt seasons due to the stability of channels maintained from recurrent floods. These

  5. Economic Development Mode and Countermeasure Research on the Nansi Lake Drainage Area Based on Circular Economy

    OpenAIRE

    Jia, Yong-fei; Peng, Li-min

    2011-01-01

    Firstly, it is pointed out that circular economy should be vigorously developed in the Nansi Lake Drainage Area, and the connotation of circular economy is expounded. Then, problems in developing circular economy in Nansi Lake Drainage Area are analyzed from the aspects of agriculture, industrial enterprises, and waste utilization. Finally, combining with the four modes of peasant household, enterprise, region and society in the development of circular economy, corresponding countermeasures a...

  6. Ice-dammed lake drainage evolution at Russell Glacier, west Greenland

    Science.gov (United States)

    Carrivick, Jonathan L.; Tweed, Fiona S.; Ng, Felix; Quincey, Duncan J.; Mallalieu, Joseph; Ingeman-Nielsen, Thomas; Mikkelsen, Andreas B.; Palmer, Steven J.; Yde, Jacob C.; Homer, Rachel; Russell, Andrew J.; Hubbard, Alun

    2017-11-01

    Glaciological and hydraulic factors that control the timing and mechanisms of glacier lake outburst floods (GLOFs) remain poorly understood. This study used measurements of lake level at fifteen minute intervals and known lake bathymetry to calculate lake outflow during two GLOF events from the northern margin of Russell Glacier, west Greenland. We used measured ice surface elevation, interpolated subglacial topography and likely conduit geometry to inform a melt enlargement model of the outburst evolution. The model was tuned to best-fit the hydrograph’s rising limb and timing of peak discharge in both events; it achieved Mean Absolute Errors of Lake water temperature, which strongly governed the enlargement rate, preconditioned the high peak discharge and short duration of these floods. We hypothesize that both GLOFs were triggered by ice dam flotation, and localised hydraulic jacking sustained most of their early-stage outflow, explaining the particularly rapid water egress in comparison to that recorded at other ice-marginal lakes. As ice overburden pressure relative to lake water hydraulic head diminished, flow became confined to a subglacial conduit. This study has emphasised the inter-play between ice dam thickness and lake level, drainage timing, lake water temperature and consequently rising stage lake outflow and flood evolution.

  7. Low Velocity Seismic Waves Produced by Stick-Slip Processes During the Drainage of Two Supraglacial Lakes in Greenland

    Science.gov (United States)

    Kenyon, P. M.; Orantes, E. J.; Grynewize, S.; Tedesco, M.

    2016-12-01

    The drainage of supraglacial lakes over the Greenland ice sheet has been shown to have a significant impact on ice dynamics and subglacial hydrology. As supraglacial lakes drain, they produce seismic waves that can be detected on both local and regional scales. Studying such waves and the originating phenomena has the potential to advance our understanding of the subglacial processes involved. Here we present the results of an analysis of high frequency seismic waves generated during the drainage of two supraglacial lakes in southwestern Greenland. The two lakes drained by contrasting mechanisms. One (Lake Half Moon) drained slowly by overflow into an existing moulin. Here GPS data, recorded during the drainage, show an increase in ice sheet velocity that begins well before the time of maximum lake depth. The other lake (Lake Ponting) drained suddenly by hydrofracture through the lake bed. In this case, the GPS data show an increase in velocity that is essentially simultaneous with the maximum lake depth. In both cases, vertical component seismograms were obtained from the Greenland Ice Sheet Monitoring Network (GLISN) for several hours before and after the lake drainage. Arrival times were picked manually, using the criterion that an arrival must have a minimum amplitude of twice the noise level. The arrivals were then plotted on graphs of time versus distance from the lake in question. Several linear trends are visible on each graph. The velocities calculated from the slopes of these trends are unexpectedly low. We suggest that one explanation for this might be that the waves are traveling in a layer of till at the base of the ice sheet, that forms a low velocity channel. When compared with GPS and lake depth data, the origin times of the waves coincide with the velocity increase in both cases. Therefore, we conclude that the waves are being generated by stick-slip processes involving the slippage of the ice sheet on an underlying layer of till.

  8. Safety, pharmacokinetics, immunogenicity, and biodistribution of (186)Re-labeled humanized monoclonal antibody BIWA 4 (Bivatuzumab) in patients with early-stage breast cancer.

    Science.gov (United States)

    Koppe, Manuel; Schaijk, Frank van; Roos, Jan; Leeuwen, Paul van; Heider, Karl-Heinz; Kuthan, Hartmut; Bleichrodt, Robert

    2004-12-01

    The aim of this prospective study was to evaluate the safety, pharmacokinetics, immunogenicity, and biodistribution of (186)Re-labeled humanized anti-CD44v6 monoclonal antibody (MAb( BIWA 4 (Bivatuzumab( in 9 patients with early-stage breast cancer. Radioimmunoscintigraphy (RIS( was performed within 1, 24, and 72 hours after administration. BIWA 4 concentration in plasma (ELISA and radioactivity measurements( and the development of human antihuman antibody (HAHA( responses was determined. The biodistribution of (186)Re-BIWA 4 was determined by radioactivity measurements in tumor and normal tissue biopsies obtained during surgery 1 week after administration. Administration of (186)Re-BIWA 4 was well tolerated by all patients and no HAHA responses were observed. The mean t(1/2) in plasma of BIWA 4 (ELISA( was 81 hours (range, 67-97(, whereas the mean radioactivity t(1/2) tended to be longer, at 105 hours (range, 90-114(. RIS unmistakably showed the tumor in 3 patients. Less clear identifications were established in 3 additional patients. In 2 patients, the tumor was wrongly identified in the contralateral breast. Median tumor CD44v6 expression, as determined by immunohistochemistry, was 70% (range, 10-90%). Mean tumor uptake was 2.96% ID/kg (range, 0.92-6.27(, with no apparent correlation with either tumor CD44v6 expression, tumor-cell cellularity, or tumor diameter. Tumor-to-nontumor ratios were unfavorable for blood, bone marrow, mammary gland tissue, and skin. The (186)Re-labeled humanized MAb BIWA 4 can safely be administered to patients with early-stage breast cancer. Tumorto- nontumor ratios were unfavorable, with no apparent correlation with CD44v6 expression, tumor-cell cellularity, or tumor diameter. BIWA 4, therefore, appears to have limitations as a vehicle for radioimmunotherapy in patients with breast cancer.

  9. Levels of infection of gastric nematodes in a flock of great cormorants (Phalacrocorax carbo) from Lake Biwa, Japan.

    Science.gov (United States)

    El-Dakhly, Kh M; El-Nahass, E; Uni, S; Tuji, H; Sakai, H; Yanai, T

    2012-03-01

    A high prevalence (86.7%) of various species of nematodes was observed in the stomach of great cormorants living in Lake Biwa, Japan. There were varying numbers of adults belonging to two common genera, Eustrongylides Jagerskiold 1909 (Nematoda: Dioctophymatidae) and Contracaecum Railliet & Henry 1912 (Nematoda: Anisakidae). The first included common adenophorean nematodes comprising a single species, Eustrongylides tubifex and the second comprised ascaroid nematodes that contained four named species: Contracaecum rudolphii Hartwich, 1964, Contracaecum microcephalum Yamaguti, 1961, Contracaecum multipapillatum Drasche, 1882 and Contracaecum chubutensis Garbin, 2008. After the prevalence and intensity of the infection had been noted, both types of nematodes were frequently observed to penetrate the mucosa and intrude into the wall of the glandular stomach, where they caused gross haemorrhage and ulceration. The Eustrongylides sp. was predominantly found in a nodular lesion of the proventricular wall, while Contracaecum spp. were observed either free in the lumen of the proventriculus or, on occasion, deeply penetrating its wall. Of the Contracaecum spp., C. rudolphii was the most prevalent. Grossly, large numbers of nematodes were present in infected stomachs (for C. rudolphii intensity was 1-34 and 3-57 nematodes in male birds and 1-21 and 1-32 in females; for C. microcephalum 1-2 and 1 in male birds and 1-2 in females; for C. multipapillatum 2 in male cormorants and no infection in females; for C. chubutensis 1-2 and 1 in male birds and 1-5 and 1 in females and for E. tubifex 1-5 nematodes in male birds and 2-8 in females). Ulcerative inflammation and hyperaemia were the most common pathological presentations, especially in areas that had been invaded by parasites. Microscopically, varying degrees of granulomatous inflammatory reactions were seen, in addition to degenerated nematodes which appeared to have deeply penetrated mucosal surfaces and were surrounded by

  10. Fluvial sediment study of Fishtrap and Dewey Lakes drainage basins, Kentucky - Virginia

    Science.gov (United States)

    Curtis, William F.; Flint, Russell F.; George, Frederick H.; Santos, John F.

    1978-01-01

    Fourteen drainage basins above Fishtrap and Dewey Lakes in the Levisa Fork and Johns Creek drainage basins of eastern Kentucky and southwestern Virginia were studied to determine sedimentation rates and origin of sediment entering the two lakes. The basins ranged in size from 1.68 to 297 square miles. Sediment yields ranged from 2,890 to 21,000 tons per square mile where surface-mining techniques predominated, and from 732 to 3 ,470 tons per square mile where underground mining methods predominated. Yields, in terms of tons per acre-foot of runoff, ranged from 2.2 to 15 for surface-mined areas, and from 0.5 to 2.7 for underground-mined areas. Water and sediment discharges from direct runoff during storms were compared for selected surface-mined and underground-mined areas. Data points of two extensively surface-mined areas, one from the current project and one from a previous project in Beaver Creek basin, McCreary County, Kentucky, grouped similarly in magnitude and by season. Disturbed areas from mining activities determined from aerial photographs reached 17 percent in one study area where extensive surface mining was being practiced. For most areas where underground mining was practiced, percentage disturbed area was almost negligible. Trap efficiency of Fishtrap Lake was 89 percent, and was 62 percent for Dewey Lake. Average annual deposition rates were 464 and 146 acre-feet for Fishtrap and Dewey Lakes, respectively. The chemical quality of water in the Levisa Fork basin has been altered by man 's activities. (Woodard-USGS)

  11. Chronology and alteration of cyclic drainage events for ice-dammed Lake Tiningnilik, Greenland, in 2010

    DEFF Research Database (Denmark)

    Haase, Eric Juergen; Furuya, Masato; Korsgaard, Niels Jákup

    pattern in nature lasting through the 19th and 20th centuries until now. In summer 2010 the lake drained after just 7 years and at a lower water stand than the 2003 pre-drainage levels. This represents an adjustment to new equilibrium conditions with the ice dam and might be an index of recent local...... climate change in Greenland. We take a close look at Lake Tiningnilik and previous studies to constrain the timing of the drainage events using historical air photos and satellite imagery starting in the 1940s and 1970s, respectively. Tiningnilik has been occasionally surveyed on the ground since the 1980...

  12. Safety, biodistribution, pharmacokinetics, and immunogenicity of 99mTc-labeled humanized monoclonal antibody BIWA 4 (bivatuzumab) in patients with squamous cell carcinoma of the head and neck.

    Science.gov (United States)

    Colnot, David R; Roos, Jan C; de Bree, Remco; Wilhelm, Abraham J; Kummer, J Alain; Hanft, Gertraud; Heider, Karl-Heinz; Stehle, Gerd; Snow, Gordon B; van Dongen, Guus A M S

    2003-09-01

    Previous studies have shown the potential of murine and chimeric anti-CD44v6 monoclonal antibodies (MAbs) for radioimmunotherapy (RIT) of head and neck squamous cell carcinoma (HNSCC). A limitation of these MAbs, however, appeared to be their immunogenicity. Therefore, humanized monoclonal antibody BIWA 4 (bivatuzumab), with an intermediate affinity for CD44v6, was recently selected. As a prelude to RIT, we evaluated the safety, tumor-targeting potential, pharmacokinetics, and immunogenicity of technetium-99m-labeled BIWA 4 in patients undergoing operations for primary HNSCC in this study. Ten patients were treated at BIWA 4 dose levels of 25 mg (n=3), 50 mg (n=4), and 100 mg (n=3). Patients received 2 mg of 750 MBq 99mTc-BIWA 4, together with 23-, 48-, and 98-mg unlabeled BIWA 4, respectively. Radioimmunoscintigraphy (RIS) was performed within 1 h and after 21 h, and patients underwent surgery at 48 h after injection. Biodistribution of 99mTc-BIWA 4 was evaluated by radioactivity measurements in blood, bone marrow, and in biopsies of a surgical specimen obtained 48 h after injection. BIWA 4 concentration in blood was assessed by ELISA and high performance liquid chromatography and related to soluble CD44v6 levels in serum samples. The development of human anti-human antibody (HAHA) responses was determined. Administration of 99mTc-BIWA 4 was well tolerated by all patients and no HAHA responses were observed. A mean t1/2 in plasma of 54.8 +/- 11.5 h, 76.1 +/- 21.8 h, and 68.5 +/- 21.2 h was found for the 25-, 50-, and 100-mg dose group, respectively. No complex formation of BIWA 4 with soluble CD44v6 in blood was observed. RIS showed targeting of primary tumors and lymph node metastases in 8 of 10 and 1 of 5 patients, respectively. The highest tumor uptake and tumor to nontumor ratios were observed for the 50-mg dose group. Tumor uptake was 12.9 +/- 5.9, 26.2 +/- 3.1, and 15.4 +/- 1.9% of the injected dose (ID)/kg for the 25-, 50-, and 100-mg dose group

  13. Spatial variations in water composition at a northern Canadian lake impacted by mine drainage

    International Nuclear Information System (INIS)

    Moncur, M.C.; Ptacek, C.J.; Blowes, D.W.; Jambor, J.L.

    2006-01-01

    Release of acid drainage from mine-waste disposal areas is a problem of international scale. Contaminated surface water, derived from mine wastes, originates both as direct surface runoff and, indirectly, as subsurface groundwater flow. At Camp Lake, a small Canadian Shield lake that is in northern Manitoba and is ice-covered 6 months of the year, direct and indirect release of drainage from an adjacent sulfide-rich tailings impoundment has severely affected the quality of the lake water. Concentrations of the products from sulfide oxidation are extremely high in the pore waters of the tailings impoundment. Groundwater and surface water derived from the impoundment discharge into a semi-isolated shallow bay in Camp Lake. The incorporation of this aqueous effluent has altered the composition of the lake water, which in turn has modified the physical limnology of the lake. Geochemical profiles of the water column indicate that, despite its shallow depth (6 m), the bay is stratified throughout the year. The greatest accumulation of dissolved metals and SO 4 is in the lower portion of the water column, with concentrations up to 8500 mg L -1 Fe, 20,000 mg L -1 SO 4 , 30 mg L -1 Zn, 100 mg L -1 Al, and elevated concentrations of Cu, Cd, Pb and Ni. Meromictic conditions and very high solute concentrations are limited to the bay. Outside the bay, solute concentrations are lower and some stratification of the water column exists. Identification of locations and composition of groundwater discharge relative to lake bathymetry is a fundamental aspect of understanding chemical evolution and physical stability of mine-impacted lakes

  14. Studies on the growth of Pediastrum biwae : Ⅲ Growth under various conditions of nitrate,trace metals and vitamins

    OpenAIRE

    石上, 三雄; 北川, 仁志

    1983-01-01

    Growth characteristics of Pediastrum biwae, which is very famous green alga in Lake Biwa, have been investigated under various conditions of nitrate, trace metals and vitamins. Adopting the total chlorophyll(chlorophyll a and b)as an indicator of the algal mass, the following properties have been revealed: 1)The optimum concentration of nitrogen(NO3-N, expressed by nitrogen weight)is about 41.2 ppm. The excess of nitrogen in the medium is rather inhibitory, reducing both the growth rate...

  15. Sediment plume response to surface melting and supraglacial lake drainages on the Greenland ice sheet

    DEFF Research Database (Denmark)

    Chu, Vena W.; Smith, Laurence C; Rennermalm, Asa K.

    2009-01-01

    ) supraglacial lake drainage events from MODIS. Results confirm that the origin of the sediment plume is meltwater release from the ice sheet. Interannual variations in plume area reflect interannual variations in surface melting. Plumes appear almost immediately with seasonal surface-melt onset, provided...... the estuary is free of landfast sea ice. A seasonal hysteresis between melt extent and plume area suggests late-season exhaustion in sediment supply. Analysis of plume sensitivity to supraglacial events is less conclusive, with 69% of melt pulses and 38% of lake drainage events triggering an increase in plume...... area. We conclude that remote sensing of sediment plume behavior offers a novel tool for detecting the presence, timing and interannual variability of meltwater release from the ice sheet....

  16. Large drainages from short-lived glacial lakes in the Teskey Range, Tien Shan Mountains, Central Asia

    Science.gov (United States)

    Narama, Chiyuki; Daiyrov, Mirlan; Duishonakunov, Murataly; Tadono, Takeo; Sato, Hayato; Kääb, Andreas; Ukita, Jinro; Abdrakhmatov, Kanatbek

    2018-04-01

    Four large drainages from glacial lakes occurred during 2006-2014 in the western Teskey Range, Kyrgyzstan. These floods caused extensive damage, killing people and livestock as well as destroying property and crops. Using satellite data analysis and field surveys of this area, we find that the water volume that drained at Kashkasuu glacial lake in 2006 was 194 000 m3, at western Zyndan lake in 2008 was 437 000 m3, at Jeruy lake in 2013 was 182 000 m3, and at Karateke lake in 2014 was 123 000 m3. Due to their subsurface outlet, we refer to these short-lived glacial lakes as the tunnel-type, a type that drastically grows and drains over a few months. From spring to early summer, these lakes either appear, or in some cases, significantly expand from an existing lake (but non-stationary), and then drain during summer. Our field surveys show that the short-lived lakes form when an ice tunnel through a debris landform gets blocked. The blocking is caused either by the freezing of stored water inside the tunnel during winter or by the collapse of ice and debris around the ice tunnel. The draining then occurs through an opened ice tunnel during summer. The growth-drain cycle can repeat when the ice-tunnel closure behaves like that of typical supraglacial lakes on debris-covered glaciers. We argue here that the geomorphological characteristics under which such short-lived glacial lakes appear are (i) a debris landform containing ice (ice-cored moraine complex), (ii) a depression with water supply on a debris landform as a potential lake basin, and (iii) no visible surface outflow channel from the depression, indicating the existence of an ice tunnel. Applying these characteristics, we examine 60 depressions (> 0.01 km2) in the study region and identify here 53 of them that may become short-lived glacial lakes, with 34 of these having a potential drainage exceeding 10 m3 s-1 at peak discharge.

  17. 137Cs distribution and geochemistry of Lena River (Siberia) drainage basin lake sediments

    International Nuclear Information System (INIS)

    Johnson-Pyrtle, A.; Scott, M.R.; Laing, T.E.; Smol, J.P.

    2000-01-01

    The Lena River is the second largest river that discharges into the Arctic Ocean. It is therefore important to determine not only the direct impact its discharge has on the 137Cs concentration of the Arctic, but also the potential its drainage basin has as a 137Cs source. 137Cs surface sediment concentrations and inventory values, which range from 4.97 to 338 Bq kg -1 and 357 to 1732 Bq m -2 , respectively, were determined for the Lena River drainage basin lake samples, via gamma analysis. The average geochemical and mineralogical composition of a subset of samples was also determined using neutron activation analysis, X-ray diffraction and X-ray fluorescence spectrometry techniques. Results of these geochemical analyses allowed for the identification of key geochemical factors that influence the distribution of 137Cs in the Lena River drainage basin. 137Cs profiles indicate that Lena River drainage basin lacustrine sediments serve as a record of 137Cs fallout. Based on the downcore 137Cs, %illite, %smectite, %Al and %Mn distribution patterns, it was concluded that a small fraction of non-selectively bound 137Cs was remobilized at depth in some cores. Inconsistencies between the actual 137Cs fallout record and the 137Cs profiles determined for the lake sediments were attributed to 137Cs remobilization in subsurface sediments. In addition to establishing the agreement between the global atmospheric fallout record and the downcore 137Cs distribution patterns determined for these sediments, results indicate that 137Cs deposited during periods of maximum atmospheric release was buried and is not susceptible to surface erosion processes. However, mean 137Cs concentrations of the lacustrine surface sediments (125 Bq kg -1 ) are still significantly higher than those of the nearby Lena River estuary (11.22 Bq kg -1 ) and Laptev Sea (6.00 Bq kg -1 ). Our study suggests that the Lena River drainage basin has the potential to serve as a source of 137Cs to the adjacent Arctic

  18. Large drainages from short-lived glacial lakes in the Teskey Range, Tien Shan Mountains, Central Asia

    Directory of Open Access Journals (Sweden)

    C. Narama

    2018-04-01

    Full Text Available Four large drainages from glacial lakes occurred during 2006–2014 in the western Teskey Range, Kyrgyzstan. These floods caused extensive damage, killing people and livestock as well as destroying property and crops. Using satellite data analysis and field surveys of this area, we find that the water volume that drained at Kashkasuu glacial lake in 2006 was 194 000  m3, at western Zyndan lake in 2008 was 437 000 m3, at Jeruy lake in 2013 was 182 000 m3, and at Karateke lake in 2014 was 123 000 m3. Due to their subsurface outlet, we refer to these short-lived glacial lakes as the tunnel-type, a type that drastically grows and drains over a few months. From spring to early summer, these lakes either appear, or in some cases, significantly expand from an existing lake (but non-stationary, and then drain during summer. Our field surveys show that the short-lived lakes form when an ice tunnel through a debris landform gets blocked. The blocking is caused either by the freezing of stored water inside the tunnel during winter or by the collapse of ice and debris around the ice tunnel. The draining then occurs through an opened ice tunnel during summer. The growth–drain cycle can repeat when the ice-tunnel closure behaves like that of typical supraglacial lakes on debris-covered glaciers. We argue here that the geomorphological characteristics under which such short-lived glacial lakes appear are (i a debris landform containing ice (ice-cored moraine complex, (ii a depression with water supply on a debris landform as a potential lake basin, and (iii no visible surface outflow channel from the depression, indicating the existence of an ice tunnel. Applying these characteristics, we examine 60 depressions (> 0.01 km2 in the study region and identify here 53 of them that may become short-lived glacial lakes, with 34 of these having a potential drainage exceeding 10 m3 s−1 at peak discharge.

  19. Early Holocene estuary development of the Hesselø Bay area, southern Kattegat, Denmark and its implication for Ancylus Lake drainage

    Science.gov (United States)

    Bendixen, Carina; Boldreel, Lars Ole; Jensen, Jørn Bo; Bennike, Ole; Hübscher, Christian; Clausen, Ole Rønø

    2017-12-01

    High-resolution shallow seismic data, sediment core information, radiocarbon dating and sequence stratigraphy have been used to interpret the late glacial to early Holocene geological evolution of Hesselø Bay in the southern Kattegat, Denmark. A reconstruction of the early Holocene coastal environment and a description of coastal processes associated with a river outlet into the bay are presented. Weichselian glacial deposits form the lowermost interpreted unit, covered by late glacial (LG) and postglacial (PG, Holocene) sediments. A funnel-shaped estuary existed at the mouth of channels in the period 10.3-9.2 cal. ka BP; the channels drained water from south to north. The early PG is characterised by estuarine and coastal deposits. The early Holocene bars that developed in the estuary are preserved as morphological features on the present-day seabed, possibly as a result of rapid relative sea-level rise. The estuary existed simultaneously with the occurrence and drainage of the Ancylus Lake. The drainage of this lake occurred through the Dana River (palaeo-Great Belt channel) into the southern Kattegat and then into the study area. The level of the Ancylus Lake in the Baltic Sea region dropped significantly at about 10.2 cal. ka BP at the same time as the estuary developed in the Kattegat region. One outcome of the present study is an enhanced understanding of the Ancylus Lake drainage path. No evidence of major erosion is seen, which indicates non-catastrophic continuous water flow from the south without major drainage events of the Ancylus Lake to the southern Kattegat. During the Littorina transgression, coastal estuarine conditions characterized the Hesselø Bay area where elongated ridges formed a bar system. As the Littorina transgression continued, back-stepping of the bar system and coastline occurred. When the transgression breached the Great Belt threshold, flooding caused major erosion throughout the study area.

  20. Neutron activation analysis of sediment core samples of Lake Erhai in southern China and a Salt Lake in India

    International Nuclear Information System (INIS)

    Toyoda, Kazuhiro; Shinozuka, Yoshitsugu; Miura, Masahiro; Moriyasu, Yuki

    2005-01-01

    The purpose of this research is in the verification of the hypothesis that the long-lived nuclide ratio of Th/Sc in the deposit sample dug up in the lake with the hinterland of the granite quality is the index of a past change of precipitation and of the event such as earthquakes. As a preceding step the relation between an environmental change and a climate change was studied by the measuring result of the ratio of Th/Sc by the neutron activation analysis about the digging core sample of the Nepalese Katmandu basin (For the past 700,000 years) and the core sample (For 40,000 years and 8,000 years of the past) in Lake Biwa. (H. Katsuta)

  1. Environmental status of the Lake Michigan region. Volume 16. Amphibians and reptiles of the Lake Michigan drainage basin

    Energy Technology Data Exchange (ETDEWEB)

    Pentecost, E.D.; Vogt, R.C.

    1976-07-01

    The focus of this report is on regional distribution of the herpetofauna of the Lake Michigan Drainage Basin. The introduction includes a brief discussion of plant communities and their associated herpetofauna, and the importance of hibernacula and migration routes. Some aspects of the status, distribution, habitat, and life history of the amphibians and reptiles of the Basin are described in an annotated checklist. Special attention is given to uncommon and endangered species. Species range is shown on distribution maps.

  2. Environmental status of the Lake Michigan region. Volume 16. Amphibians and reptiles of the Lake Michigan drainage basin

    International Nuclear Information System (INIS)

    Pentecost, E.D.; Vogt, R.C.

    1976-07-01

    The focus of this report is on regional distribution of the herpetofauna of the Lake Michigan Drainage Basin. The introduction includes a brief discussion of plant communities and their associated herpetofauna, and the importance of hibernacula and migration routes. Some aspects of the status, distribution, habitat, and life history of the amphibians and reptiles of the Basin are described in an annotated checklist. Special attention is given to uncommon and endangered species. Species range is shown on distribution maps

  3. Characterizing the Frequency and Elevation of Rapid Drainage Events in West Greenland

    Science.gov (United States)

    Cooley, S.; Christoffersen, P.

    2016-12-01

    Rapid drainage of supraglacial lakes on the Greenland Ice Sheet is critical for the establishment of surface-to-bed hydrologic connections and the subsequent transfer of water from surface to bed. Yet, estimates of the number and spatial distribution of rapidly draining lakes vary widely due to limitations in the temporal frequency of image collection and obscureness by cloud. So far, no study has assessed the impact of these observation biases. In this study, we examine the frequency and elevation of rapidly draining lakes in central West Greenland, from 68°N to 72.6°N, and we make a robust statistical analysis to estimate more accurately the likelihood of lakes draining rapidly. Using MODIS imagery and a fully automated lake detection method, we map more than 500 supraglacial lakes per year over a 63000 km2 study area from 2000-2015. Through testing four different definitions of rapidly draining lakes from previously published studies, we find that the number of rapidly draining lakes varies from 3% to 38%. Logistic regression between rapid drainage events and image sampling frequency demonstrates that the number of rapid drainage events is strongly dependent on cloud-free observation percentage. We then develop three new drainage criteria and apply an observation bias correction that suggests a true rapid drainage probability between 36% and 45%, considerably higher than previous studies without bias assessment have reported. We find rapid-draining lakes are on average larger and disappear earlier than slow-draining lakes, and we also observe no elevation differences for the lakes detected as rapidly draining. We conclude a) that methodological problems in rapid drainage research caused by observation bias and varying detection methods have obscured large-scale rapid drainage characteristics and b) that the lack of evidence for an elevation limit on rapid drainage suggests surface-to-bed hydrologic connections may continue to propagate inland as climate warms.

  4. Cosmogenic 10Be Dating of Northern Quebec-Labrador Glacial Lake Shorelines and Drainage Deposits: Implications for the Final Meltwater Discharges of the Last Deglaciation

    Science.gov (United States)

    Roy, M.; Dube-Loubert, H.; Schaefer, J. M.; Hébert, S.

    2017-12-01

    The decay of the Laurentide ice sheet played an important role in the climate variability of the last deglaciation, notably through large discharges of meltwater from glacial lakes that disturbed the Atlantic meridional overturning oceanic circulation (AMOC). These former climate-forcing events are now under focus due to growing evidence showing that the present-day increase in freshwater releases from Greenland and other Arctic glaciers may potentially lead to a slowdown of the AMOC and cause important climate feedbacks. In northern Quebec and Labrador, the end of the deglaciation led to the formation of at least 10 important glacial lakes that drained into the nearby Labrador Sea where repeated meltwater discharges could have destabilized the ocean surface conditions in this key sector of the North Atlantic Ocean. Although the drainage of these ice-dammed lakes may form a good analogue for modern processes, the lack of direct constraints on the physiographic configuration and temporal evolution of these lakes limits our understanding of the timing and climate impact of these final meltwater pulses. Here we applied cosmogenic 10Be dating to raised boulder shorelines belonging to Lake Naskaupi, one of the largest glacial lakes in northern Quebec and Labrador. We reconstructed the lake extent and meltwater volume, as well as its lake-level history by systematic mapping of geomorphic features. We sampled a total of 16 boulders at 4 sites along the valley. In addition, we dated five boulders belonging to a large-scale outburst flood deposit recording the abrupt drainage of the lake. The distribution of the 21 ages shows a remarkable consistency, yielding a mean age of 7.8 ± 0.4 ka (1 outlier excluded). The ages from the shorelines are indistinguishable from those of the outburst flood deposit, suggesting that Lake Naskaupi existed for a relatively short time span. These new chronological data constrain the timing of the lake development and attendant drainage

  5. THE EVALUATION OF THE WATER CHEMISTRY AND QUALITY FOR THE LAKES FROM THE SOUTH OF THE HILLY PLAIN OF JIJIA (BAHLUI DRAINAGE BASIN)

    OpenAIRE

    Ionuţ MINEA

    2010-01-01

    In order to highlight the quality of the lake waters from the Bahlui drainage basin, we chose to analyse four principal lakes (Pârcovaci, Tansa, Chiriţa, Podu Iloaiei) and six secundary lakes (Aroneanu I and II, Ciric I, II and III and Cucuteni). The global presentation of the lakes’ water chemistry and quality is a sum of two different ways of analysis: the first based on standards (promulgated in 2006), according to which the lakes are analyzed as static ecosystem (the quality of the water ...

  6. Methane emissions from permafrost thaw lakes limited by lake drainage.

    NARCIS (Netherlands)

    van Huissteden, J.; Berrittella, C.; Parmentier, F.J.W.; Mi, Y.; Maximov, T.C.; Dolman, A.J.

    2011-01-01

    Thaw lakes in permafrost areas are sources of the strong greenhouse gas methane. They develop mostly in sedimentary lowlands with permafrost and a high excess ground ice volume, resulting in large areas covered with lakes and drained thaw-lake basins (DTLBs; refs,). Their expansion is enhanced by

  7. The influence of flow-through saline gravel pit lakes on the hydrologic budget and hydrochemistry of a Mediterranean drainage basin

    NARCIS (Netherlands)

    Mollema, P.N.; Antonellini, Marco; Dinelli, Enrico; Greggio, Nicolas; Stuijfzand, Pieter

    2015-01-01

    Flow-through brackish gravel pit lakes near the Adriatic Coast of Emilia Romagna (Italy) in the Mediterranean have a large influence on the hydrologic budget of the watershed. Strong evaporation in combination with intense drainage of the low lying basins enhances groundwater inflow into the

  8. Inventory of drainage wells and potential sources of contaminants to drainage-well inflow in Southwest Orlando, Orange County, Florida

    Science.gov (United States)

    Taylor, George Fred

    1993-01-01

    Potential sources of contaminants that could pose a threat to drainage-well inflow and to water in the Floridan aquifer system in southwest Orlando, Florida, were studied between October and December 1990. Drainage wells and public-supply wells were inventoried in a 14-square-mile area, and available data on land use and activities within each drainage well basin were tabulated. Three public-supply wells (tapping the Lower Floridan aquifer) and 38 drainage wells (open to the Upper Floridan aquifer) were located in 17 drainage basins within the study area. The primary sources of drainage-well inflow are lake overflow, street runoff, seepage from the surficial aquifer system, and process-wastewater disposal. Drainage-well inflow from a variety of ares, including resi- dential, commercial, undeveloped, paved, and industrial areas, are potential sources of con- taminants. The four general types of possible contaminants to drainage-well inflow are inorganic chemicals, organic compounds, turbidity, and microbiological contaminants. Potential contami- nant sources include plant nurseries, citrus groves, parking lots, plating companies, auto- motive repair shops, and most commonly, lake- overflow water. Drainage wells provide a pathway for contaminants to enter the Upper Floridan aquifer and there is a potential for contaminants to move downward from the Upper Floridan to the Lower Floridan aquifer.

  9. Seismic observations of subglacial water discharge from glacier-dammed lake drainage at Lemon Creek Glacier, Alaska

    Science.gov (United States)

    Labedz, C. R.; Bartholomaus, T. C.; Gimbert, F.; Amundson, J. M.; Vore, M. E.; Karplus, M. S.; Tsai, V. C.

    2017-12-01

    Subglacial water flow affects the dynamics of glaciers, influencing basal sliding, sediment transport, fracturing, and terminus dynamics. However, the difficulty of directly observing glacial hydrologic systems creates significant challenges in understanding such glacier behavior. Recently-developed descriptions of ground motion generated by subglacial water flow provide a promising basis for new and unique characterization of glacial hydrologic systems. Particularly, high-frequency ( 1.5-20 Hz) seismic tremor observed near glaciers has been shown to correlate with subglacial runoff. In addition, specific properties of subglacial water flow like water pressure, conduit size, sediment flux, and grain size can be inferred by examining hysteretic behavior over time between different parts of these signals. In this study, we observe the seismic signals generated by subglacial water flow using a high-density array of more than 100 nodes deployed for 10-25 days, and six broadband seismometers deployed for 80 days at Lemon Creek Glacier, Alaska. Specifically, we examine the 36-hour drainage of a glacier-dammed lake into subglacial conduits, comparing hydrologic metrics such as lake level, precipitation, and outlet stream flow rate to the power of seismic signals. Our node array captures this annually-significant hydraulic transient with sensors spaced approximately every 250 m over the majority of the 5.7 km long glacier. This and other lake drainage events provide natural experiments for exploring glaciohydraulic tremor, because the increased water flux through the glacier increases the power of the tremor and hosts the hysteretic behaviors described previously. Analysis of the tremor from events such as this can be extended to further understand subglacial runoff at Lemon Creek glacier and for glacier hydrology in general.

  10. National Water-Quality Assessment Program, western Lake Michigan drainages: Summaries of liaison committee meeting, Green Bay, Wisconsin, March 28-29, 1995

    Science.gov (United States)

    Peters, Charles A.

    1995-01-01

    The Western Lake Michigan Drainages (WMIC) study unit, under investigation since 1991, drains 20,000 square miles (mi2) in eastern Wisconsin and Upper Michigan (fig. 1). The major water-quality issues in the WMIC study unit are: (1) nonpoint-source contamination of surface and ground water by agricultural chemicals, (2) contamination in bottom sediments of rivers and harbors by toxic substances, including polychlorinated biphenyls (PCB's), other synthetic organic compounds, and trace elements, (3) nutrient enrichment of rivers and lakes resulting from nonpoint- and point-source discharges, and (4) acidification and mercury contamination of lakes in poorly buffered watersheds in the northwestern part of the study unit.

  11. Lake and lake-related drainage area parameters for site investigation program

    Energy Technology Data Exchange (ETDEWEB)

    Blomqvist, P.; Brunberg, A.K. [Uppsala Univ. (Sweden). Dept. of Limnology; Brydsten, L [Umeaa Univ. (Sweden). Dept. of Ecology and Environmental Science

    2000-09-01

    In this paper, a number of parameters of importance to a preliminary determination of the ecological function of lakes are presented. The choice of parameters have been made with respect to a model for the determination of the nature conservation values of lakes which is currently being developed by the authors of this report, but is also well suited for a general description of the lake type and the functioning of the inherent ecosystem. The parameters have been divided into five groups: (1) The location of the object relative important gradients in the surrounding nature; (2) The lake catchment area and its major constituents; (3) The lake morphometry; (4) The lake ecosystem; (5) Human-induced damages to the lake ecosystem. The first two groups, principally based on the climate, hydrology, geology and vegetation of the catchment area represent parameters that can be used to establish the rarity and representativity of the lake, and will in the context of site investigation program be used as a basis for generalisation of the results. The third group, the lake morphometry parameters, are standard parameters for the outline of sampling programmes and for calculations of the physical extension of different key habitats in the system. The fourth group, the ecosystem of the lake, includes physical, chemical and biological parameters required for determination of the stratification pattern, light climate, influence from the terrestrial ecosystem of the catchment area, trophic status, distribution of key habitats, and presence of fish and rare fauna and flora in the lake. In the context of site investigation program, the parameters in these two groups will be used for budget calculations of the flow of energy and material in the system. The fifth group, finally, describes the degree on anthropogenic influence on the ecosystem and will in the context of site investigation programmes be used to judge eventual malfunctioning within the entire, or parts of, the lake

  12. Lake and lake-related drainage area parameters for site investigation program

    International Nuclear Information System (INIS)

    Blomqvist, P.; Brunberg, A.K.; Brydsten, L

    2000-09-01

    In this paper, a number of parameters of importance to a preliminary determination of the ecological function of lakes are presented. The choice of parameters have been made with respect to a model for the determination of the nature conservation values of lakes which is currently being developed by the authors of this report, but is also well suited for a general description of the lake type and the functioning of the inherent ecosystem. The parameters have been divided into five groups: 1) The location of the object relative important gradients in the surrounding nature; 2) The lake catchment area and its major constituents; 3) The lake morphometry; 4) The lake ecosystem; 5) Human-induced damages to the lake ecosystem. The first two groups, principally based on the climate, hydrology, geology and vegetation of the catchment area represent parameters that can be used to establish the rarity and representativity of the lake, and will in the context of site investigation program be used as a basis for generalisation of the results. The third group, the lake morphometry parameters, are standard parameters for the outline of sampling programmes and for calculations of the physical extension of different key habitats in the system. The fourth group, the ecosystem of the lake, includes physical, chemical and biological parameters required for determination of the stratification pattern, light climate, influence from the terrestrial ecosystem of the catchment area, trophic status, distribution of key habitats, and presence of fish and rare fauna and flora in the lake. In the context of site investigation program, the parameters in these two groups will be used for budget calculations of the flow of energy and material in the system. The fifth group, finally, describes the degree on anthropogenic influence on the ecosystem and will in the context of site investigation programmes be used to judge eventual malfunctioning within the entire, or parts of, the lake ecosystem

  13. Safety, Pharmacokinetics, Immunogenicity, and Biodistribution of (186)Re-Labeled Humanized Monoclonal Antibody BIWA 4 (Bivatuzumab( in Patients with Early-Stage Breast Cancer.

    NARCIS (Netherlands)

    Koppe, M.; Schaijk, F. van; Roos, J.C.; Leeuwen, P.; Heider, K.H.; Kuthan, H.; Bleichrodt, R.P.

    2004-01-01

    The aim of this prospective study was to evaluate the safety, pharmacokinetics, immunogenicity, and biodistribution of (186)Re-labeled humanized anti-CD44v6 monoclonal antibody (MAb( BIWA 4 (Bivatuzumab( in 9 patients with early-stage breast cancer. Radioimmunoscintigraphy (RIS( was performed within

  14. [Effects of community identity and topophilia on environmentally-conscious behavior].

    Science.gov (United States)

    Nonami, Hiroshi; Kato, Junzo

    2009-04-01

    This study classified environmentally-conscious behaviors of residents (n = 335) along Lake Biwa as a common goods into personal and group behavioral intentions, and examined the determinants of these intentions. Identification with the community was a social identity, and differed from attachment to Lake Biwa, which was defined as topophilia. The results indicated that group behavior was affected by topophilia, while personal behavior was influenced by general attitudes about the environmental problems of the lake and evaluations of the cost for the behavior. Community identity had a significant effect on both personal and group behavior. Rational or emotional decision making processes resulted in two different types of environmentally-conscious behaviors.

  15. Delineating the Drainage Structure and Sources of Groundwater Flux for Lake Basaka, Central Rift Valley Region of Ethiopia

    Directory of Open Access Journals (Sweden)

    Megersa Olumana Dinka

    2017-11-01

    Full Text Available As opposed to most of the other closed basin type rift valley lakes in Ethiopia, Lake Basaka is found to be expanding at an alarming rate. Different studies indicated that the expansion of the lake is challenging the socio-economics and environment of the region significantly. This study result and previous reports indicated that the lake’s expansion is mostly due to the increased groundwater (GW flux to the lake. GW flux accounts for about 56% of the total inflow in recent periods (post 2000 and is found to be the dominant factor for the hydrodynamics and existence of the lake. The analysis of the drainage network for the area indicates the existence of a huge recharge area on the western and upstream side of the catchment. This catchment has no surface outlet; hence most of the incoming surface runoff recharges the GW system. The recharge area is the main source of GW flux to the lake. In addition to this, the likely sources/causes of GW flux to the lake could be: (i an increase of GW recharge following the establishment of irrigation schemes in the region; (ii subsurface inflow from far away due to rift system influence, and (iii lake neotectonism. Overall, the lake’s expansion has damaging effect to the region, owing to its poor water quality; hence the identification of the real causes of GW flux and mitigation measures are very important for sustainable lake management. Therefore a comprehensive and detailed investigation of the parameters related to GW flux and the interaction of the lake with the GW system of the area is highly recommended.

  16. The 2005 catastrophic acid crater lake drainage, lahar, and acidic aerosol formation at Mount Chiginagak volcano, Alaska, USA: Field observations and preliminary water and vegetation chemistry results

    Science.gov (United States)

    Schaefer, J.R.; Scott, W.E.; Evans, William C.; Jorgenson, J.; McGimsey, R.G.; Wang, B.

    2008-01-01

    A mass of snow and ice 400-m-wide and 105-m-thick began melting in the summit crater of Mount Chiginagak volcano sometime between November 2004 and early May 2005, presumably owing to increased heat flux from the hydrothermal system, or possibly from magma intrusion and degassing. In early May 2005, an estimated 3.8??106 m3 of sulfurous, clay-rich debris and acidic water, with an accompanying acidic aerosol component, exited the crater through a tunnel at the base of a glacier that breaches the south crater rim. Over 27 km downstream, the acidic waters of the flood inundated an important salmon spawning drainage, acidifying Mother Goose Lake from surface to depth (approximately 0.5 km3 in volume at a pH of 2.9 to 3.1), killing all aquatic life, and preventing the annual salmon run. Over 2 months later, crater lake water sampled 8 km downstream of the outlet after considerable dilution from glacial meltwater was a weak sulfuric acid solution (pH = 3.2, SO4 = 504 mg/L, Cl = 53.6 mg/L, and F = 7.92 mg/L). The acid flood waters caused severe vegetation damage, including plant death and leaf kill along the flood path. The crater lake drainage was accompanied by an ambioructic flow of acidic aerosols that followed the flood path, contributing to defoliation and necrotic leaf damage to vegetation in a 29 km2 area along and above affected streams, in areas to heights of over 150 m above stream level. Moss species killed in the event contained high levels of sulfur, indicating extremely elevated atmospheric sulfurcontent. The most abundant airborne phytotoxic constituent was likely sulfuric acid aerosols that were generated during the catastrophic partial crater lake drainage event. Two mechanisms of acidic aerosol formation are proposed: (1) generation of aerosol mist through turbulent flow of acidic water and (2) catastrophic gas exsolution. This previously undocumented phenomenon of simultaneous vegetationdamaging acidic aerosols accompanying drainage of an acidic crater

  17. Specific accumulation of 20 trace elements in great cormorants (Phalacrocorax carbo) from Japan

    International Nuclear Information System (INIS)

    Nam, Dong-Ha; Anan, Yasumi; Ikemoto, Tokutaka; Okabe, Yuko; Kim, Eun-Young; Subramanian, Annamalai; Saeki, Kazutoshi; Tanabe, Shinsuke

    2005-01-01

    This study is to elucidate the specific accumulation of 20 trace elements in tissues/organs of great cormorants from two different colonies (Lake Biwa and Mie) in Japan. In the body distribution of trace elements, some elements revealed tissue-specific accumulation such as most of the burden of Mo, Ag and Cd in liver, Tl and Cd in kidney, Cu, Rb and Cs in muscle, and V, Sr and Ba in bone. Gender-related variation was not observed in both populations for most of the trace elements, except for higher hepatic Sr in males from Lake Biwa. Hepatic V, muscular Hg and Tl, and Cd in liver, kidney and muscle increased with growth. Comparison of trace element levels in tissues between the two colonies showed that Cr, Rb, Sr, Cd, Cs, Ba and Tl levels were higher in Lake Biwa than in Mie, whereas Zn, Co and Hg in Mie samples were greater than Lake Biwa. Variations of elemental levels in stomach contents also showed similar patterns, thus, showing that dietary sources tended to be the main factor for these regional variations. Toxic Hg and Cd concentrations in the liver of cormorants from the two colonies were lower than those from other areas, implying relatively low exposure to these metals in the present study sites. Concentrations of V, Co, Ag, Cd, Cs, Hg, Tl, Pb and Bi in liver remained more or less at the same level between 1993 and 2003, while hepatic Cr, Mn, Cu, Zn, Se, Rb, Sr and Ba showed apparent decrease, which might be related to the biological factors. - Dietary sources seemed to be the main reason for variable results

  18. RECOGNITION OF DRAINAGE TUNNELS DURING GLACIER LAKE OUTBURST EVENTS FROM TERRESTRIAL IMAGE SEQUENCES

    Directory of Open Access Journals (Sweden)

    E. Schwalbe

    2016-06-01

    Full Text Available In recent years, many glaciers all over the world have been distinctly retreating and thinning. One of the consequences of this is the increase of so called glacier lake outburst flood events (GLOFs. The mechanisms ruling such GLOF events are still not yet fully understood by glaciologists. Thus, there is a demand for data and measurements that can help to understand and model the phenomena. Thereby, a main issue is to obtain information about the location and formation of subglacial channels through which some lakes, dammed by a glacier, start to drain. The paper will show how photogrammetric image sequence analysis can be used to collect such data. For the purpose of detecting a subglacial tunnel, a camera has been installed in a pilot study to observe the area of the Colonia Glacier (Northern Patagonian Ice Field where it dams the Lake Cachet II. To verify the hypothesis, that the course of the subglacial tunnel is indicated by irregular surface motion patterns during its collapse, the camera acquired image sequences of the glacier surface during several GLOF events. Applying tracking techniques to these image sequences, surface feature motion trajectories could be obtained for a dense raster of glacier points. Since only a single camera has been used for image sequence acquisition, depth information is required to scale the trajectories. Thus, for scaling and georeferencing of the measurements a GPS-supported photogrammetric network has been measured. The obtained motion fields of the Colonia Glacier deliver information about the glacier’s behaviour before during and after a GLOF event. If the daily vertical glacier motion of the glacier is integrated over a period of several days and projected into a satellite image, the location and shape of the drainage channel underneath the glacier becomes visible. The high temporal resolution of the motion fields may also allows for an analysis of the tunnels dynamic in comparison to the changing

  19. NPDES Permit for Leadville Mine Drainage Tunnel Treatment Plant in Colorado

    Science.gov (United States)

    Under NPDES permit CO-0021717, the U.S. Bureau of Reclamation is authorized to discharge from the Leadville Mine Drainage Tunnel Treatment Plant in Lake County, Colorado to an unnamed drainage way tributary to the East Fork of the Arkansas River.

  20. Correlation of the oldest Toba Tuff to sediments in the central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; ShyamPrasad, M.; Babu, E.V.S.S.K.

    of the late Pleistocene eruption of Toba, north Sumatra; Nature 276 574–577. Nishimura S, Abe E, Yokoyama T, Wirasantosa S, Dharma A and Danau 1977 Toba – The outline of lake Toba, North Sumatra, Indonesia; Paleolimnology of Lake Biwa and the Japanese...

  1. Drainage systems of Lonar Crater, India: Contributions to Lonar Lake hydrology and crater degradation

    Science.gov (United States)

    Komatsu, Goro; Senthil Kumar, P.; Goto, Kazuhisa; Sekine, Yasuhito; Giri, Chaitanya; Matsui, Takafumi

    2014-05-01

    Lonar, a 1.8-km-diameter impact crater in India, is a rare example of terrestrial impact craters formed in basaltic bedrock. The estimated age of the crater ranges widely from less than 12 ka to over 600 ka, but the crater preserves a relatively pristine morphology. We conducted a study of various drainage systems of Lonar Crater. The crater floor hosts a shallow 5-m-deep lake, which fluctuates seasonally. Our investigation reveals that the lake level is influenced by surface runoff that is active during the monsoon and groundwater input effective during both the rainy and the dry seasons. The groundwater discharge is observed as springs on the inner rim walls corresponding to weathered vesicular basalt and/or proximal ejecta, which are underlain by thick massive basalt layers. This observation indicates that groundwater movement is lithologically controlled: it passes preferentially through permeable vesicular basalt or proximal ejecta but is hindered in less permeable massive basalt. It is hypothesized that groundwater is also structurally controlled by dipping of basalt layers, interconnectivity of the permeable lithologic units through fractures, and preferential pathways such as fractures within the permeable lithologic units. Investigation on hydrological processes at Lonar Crater and its lake could provide useful insights into purported paleo-crater lakes presumably formed in the basaltic crust of Mars. The Lonar Crater interior shows signs of degradation in the forms of gullies and debris flows, and the Dhar valley incising in the rim leading to form a fan delta. The ejecta surface is characterized by the presence of channels, originating from the rim area and extending radially away from the crater center. The channels probably resulted from surface runoff, and its erosion contributes to the removal of the ejecta. Lonar Crater is a valuable analog site for studying degradation processes with potential application to impact craters occurring on

  2. Lake-sediment evidence for the date of deglaciation of the Hidden Lake area, Kenai Peninsula, Alaska

    Science.gov (United States)

    Rymer, Michael J.; Sims, John D.

    1982-06-01

    An abrupt environmental change is reflected in a core from Hidden Lake, Alaska, by differences in sediment type, chlorite crystallinity, and content of organic carbon and water of the sediments. This abrupt change in the sedimentary record occurred about 14,500 14C yr ago and probably marks the time of recession of the glacier from the Hidden Lake drainage basin. Deglaciation of the area was then underway, and rock flour was being deposited in the lake. After recession of the glacier from the Hidden Lake drainage basin, rock flour was no longer introduced, and organic-matter content of the sediment increased. By the dating of these changes in sediment type, we show that retreat of glaciers in this area took place significantly earlier than previously estimated; this agrees with the timing of retreat of alpine glaciers elsewhere in western North America.

  3. Land drainage strategies to cope with climate change in the Netherlands

    NARCIS (Netherlands)

    Ritzema, H.P.; Stuyt, L.C.P.M.

    2015-01-01

    Since the Middle Ages the Dutch have reclaimed many lakes and parts of the sea, creating polders. Drainage is required to use the land: for the inhabitants, for agriculture and for nature. Traditionally drainage was by gravity: through open (and later pipe) drains excess rainfall was transferred

  4. Drainage divides, Massachusetts; Blackstone and Thames River basins

    Science.gov (United States)

    Krejmas, Bruce E.; Wandle, S. William

    1982-01-01

    Drainage boundaries for selected subbasins of the Blackstone and Thames River basins in eastern Hampden, eastern Hampshire, western Norfolk, southern Middlesex, and southern Worcester Counties, Massachusetts, are delineated on 12 topographic quadrangle maps at a scale of 1:24,000. Drainage basins are shown for all U.S. Geological Survey data-collection sites and for mouths of major rivers. Drainage basins are shown for the outlets of lakes or ponds and for streams where the drainage area is greater than 3 square miles. Successive sites along watercourses are indicated where the intervening area is at least 6 miles on tributary streams or 15 square miles along the Blackstone River, French River, or Quinebaug River. (USGS)

  5. Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska

    Science.gov (United States)

    Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey Walter

    2012-01-01

    Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene on the northern Seward Peninsula, Alaska. Most detectable lake drainage events occurred within the last 4,000 years with the highest drainage frequency during the medieval climate anomaly. Peat accumulation rates were highest in young (50–500 years) drained lake basins (35.2 g C m−2 yr−1) and decreased exponentially with time since drainage to 9 g C m−2 yr−1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index (NDVI); Minimum Noise Fraction (MNF)) from Landsat satellite data revealed significant relationships between peat thickness and mean basin NDVI or MNF. By upscaling observed relationships, we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4–6.6 Tg organic C in drained lake basin terrestrial peat. Peat accumulation in drained lake basins likely serves to offset greenhouse gas release from thermokarst-impacted landscapes and should be incorporated in landscape-scale C budgets.

  6. A critical review of the development, current hotspots, and future directions of Lake Taihu research from the bibliometrics perspective.

    Science.gov (United States)

    Zhang, Yunlin; Yao, Xiaolong; Qin, Boqiang

    2016-07-01

    Lake Taihu, as the important drinking water source of the Yangtze River Delta urban agglomeration and the third largest freshwater lake in China, has experienced serious lake eutrophication and water quality deterioration in the past three decades. Growing scientific, political, and public attention has been given to the water quality of Lake Taihu. This study aimed to conduct a comparative quantitative and qualitative analysis of the development, current hotspots, and future directions of Lake Taihu research using a bibliometric analysis of eight well-studied lakes (Lake Taihu, Lake Baikal, Lake Biwa, Lake Erie, Lake Michigan, Lake Ontario, Lake Superior and Lake Victoria) around the world based on the Science Citation Index (SCI) database. A total of 1582 papers discussing Lake Taihu research were published in 322 journals in the past three decades. However, the first paper about Lake Taihu research was not found in the SCI database until 1989, and there were only zero, one, or two papers each year from 1989 to 1995. There had been rapid development in Lake Taihu research since 1996 and a sharp increase in papers since 2005. A keyword analysis showed that "sediment," "eutrophication", "Microcystis aeruginosa", "cyanobacterial blooms", and "remote sensing" were the most frequently used keywords of the study subject. Owing to its significant impact on aquatic ecosystems, a crucial emphasis has been placed on climate change recently. In addition, the future focuses of research directions, including (1) environmental effects of physical processes; (2) nutrient cycles and control and ecosystem responses; (3) cyanobacteria bloom monitoring, causes, forecast and management; (4) eutrophication and climate change interactions; and (5) ecosystem degradation mechanism and ecological practice of lake restoration, are presented based on the keyword analysis. Through multidisciplinary fields (physics, chemistry, and biology) cross and synthesis study of Lake Taihu, the

  7. Variety, State and Origin of Drained Thaw Lake Basins in West-Siberian North

    Science.gov (United States)

    Kirpotin, S.; Polishchuk, Y.; Bryksina, N.; Sugaipova, A.; Pokrovsky, O.; Shirokova, L.; Kouraev, A.; Zakharova, E.; Kolmakova, M.; Dupre, B.

    2009-04-01

    Drained thaw lake basins in Western Siberia have a local name "khasyreis" [1]. Khasyreis as well as lakes, ponds and frozen mounds are invariable element of sub-arctic frozen peat bogs - palsas and tundra landscapes. In some areas of West-Siberian sub-arctic khasyreis occupy up to 40-50% of total lake area. Sometimes their concentration is so high that we call such places ‘khasyrei's fields". Khasyreis are part of the natural cycle of palsa complex development [1], but their origin is not continuous and uniform in time and, according to our opinion, there were periods of more intensive lake drainage and khasyrei development accordingly. These times were corresponding with epochs of climatic warming and today we have faced with one of them. So, last years this process was sufficiently activated in the south part of West-Siberian sub-arctic [2]. It was discovered that in the zone of continuous permafrost thermokarst lakes have expanded their areas by about 10-12%, but in the zone of discontinuous permafrost the process of their drainage prevails. These features are connected with the thickness of peat layers which gradually decreases to the North, and thus have reduced the opportunity for lake drainage in northern areas. The most typical way of khasyrei origin is their drainage to the bigger lakes which are always situated on the lower levels and works as a collecting funnels providing drainage of smaller lakes. The lower level of the big lake appeared when the lake takes a critical mass of water enough for subsidence of the lake bottom due to the melting of underlaying rocks [2]. Another one way of lake drainage is the lake intercept by any river. Lake drainage to the subsurface (underlaying rocks) as some authors think [3, 4] is not possible in Western Siberia, because the thickness of permafrost is at list 500 m here being safe confining bed. We mark out few stages of khasyrei development: freshly drained, young, mature and old. This row reflects stages of

  8. Periodic outburst floods from an ice-dammed lake in East Greenland.

    Science.gov (United States)

    Grinsted, Aslak; Hvidberg, Christine S; Campos, Néstor; Dahl-Jensen, Dorthe

    2017-08-30

    We report evidence of four cycles of outburst floods from Catalina Lake, an ice-dammed lake in East Greenland, identified in satellite imagery between 1966-2016. The lake measures 20-25 km 2 , and lake level drops 130-150 m in each event, corresponding to a water volume of 2.6-3.4 Gt, and a release of potential energy of 10 16  J, among the largest outburst floods reported in historical times. The drainage cycle has shortened systematically, and the lake filling rate has increased over each cycle, suggesting that the drainage pattern is changing due to climate warming with possible implications for environmental conditions in Scoresbysund fjord.

  9. Modern thermokarst lake dynamics in the continuous permafrost zone, northern Seward Peninsula, Alaska

    Science.gov (United States)

    Jones, Benjamin M.; Grosse, G.; Arp, C.D.; Jones, M.C.; Walter, Anthony K.M.; Romanovsky, V.E.

    2011-01-01

    Quantifying changes in thermokarst lake extent is of importance for understanding the permafrost-related carbon budget, including the potential release of carbon via lake expansion or sequestration as peat in drained lake basins. We used high spatial resolution remotely sensed imagery from 1950/51, 1978, and 2006/07 to quantify changes in thermokarst lakes for a 700 km2 area on the northern Seward Peninsula, Alaska. The number of water bodies larger than 0.1 ha increased over the entire observation period (666 to 737 or +10.7%); however, total surface area decreased (5,066 ha to 4,312 ha or -14.9%). This pattern can largely be explained by the formation of remnant ponds following partial drainage of larger water bodies. Thus, analysis of large lakes (>40 ha) shows a decrease of 24% and 26% in number and area, respectively, differing from lake changes reported from other continuous permafrost regions. Thermokarst lake expansion rates did not change substantially between 1950/51 and 1978 (0.35 m/yr) and 1978 and 2006/07 (0.39 m/yr). However, most lakes that drained did expand as a result of surface permafrost degradation before lateral drainage. Drainage rates over the observation period were stable (2.2 to 2.3 per year). Thus, analysis of decadal-scale, high spatial resolution imagery has shown that lake drainage in this region is triggered by lateral breaching and not subterranean infiltration. Future research should be directed toward better understanding thermokarst lake dynamics at high spatial and temporal resolution as these systems have implications for landscape-scale hydrology and carbon budgets in thermokarst lake-rich regions in the circum-Arctic.

  10. Evaluation of the effects of water hardness and chemical pollutants on the zooplankton community in uranium mining lakes with acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, H.; Ferrari, C.; Nascimento, M.R. [Brazilian Nulcear Energy Commission/Pocos de Caldas Laboratory (Brazil); Rodgher, S. [Universidade Estadual Paulista Julio de Mesquita Filho/Science and Technology Institute (Brazil); Wisniewski, M.J. [Alfenas Federal University/Limnology Laboratory (Brazil)

    2014-07-01

    Several mining lakes are characterized by the inorganic pollution of its waters, known as acid mine drainage (AMD). The current study was developed in order to evaluate the effect of water hardness and chemical pollutants on the richness and density of the zoo-planktonic community species. A seasonal study was conducted in a uranium mining lake affected by AMD. In environmental conditions of extremely high hardness water values (960.3 to 1284,9 mg/l), zoo-planktonic species have indicated resistance to the combined effect of elevated average concentrations of chemical pollutants such as Al (81.9 mg/l), Zn (15.5 mg/l), Mn (102.8 mg/l), U (2.9 mg/l) and low pH values (average = 3.8). Thus, in environments of extreme chemical conditions, such as a uranium mining lake affected by AMD, the hardness showed to be the best predictor of the zoo-planktonic community richness, indicating a protective effect of ions Ca{sup +2} over in special to Bosminopsis deitersi, Bosmina sp., Keratella americana and K. cochlearis. Document available in abstract form only. (authors)

  11. Comparative survey of petroleum hydrocarbons i lake sediments

    Energy Technology Data Exchange (ETDEWEB)

    Wakeham, S G

    1976-11-01

    Hydrocarbon distribution in sediments from three lakes in Washington State were studied and found to be related to the level of human activity in the respective drainage basins. Petroleum hydrocarbon contamination was found in surface sediments of a lake surrounded by a major city, compared to no detectable contamination in a lake located in a National Park.

  12. Ecosystem site description - an approach to quantify transport and accumulation of matter in a drainage area

    International Nuclear Information System (INIS)

    Soderback, B.; Kautsky, U.; Lindborg, T.

    2004-01-01

    The Swedish Nuclear Fuel and Waste Management Co. (SKB) presently perform site investigations at two sites in Sweden for a future repository of spent nuclear fuel. The safety assessment of a potential repository will, among other methods, use an approach where transport and accumulation of radionuclides is modelled by quantifying the pathways of carbon/nitrogen/phosphorous in the ecosystem. Since water is the most important medium for transportation of matter, the obvious delimitation of an area for quantification of matter transport is the drainage area. This study describes how site-specific data on surface water chemistry and hydrology, measured at several points along the flow paths of a drainage area, can be used to describe and quantify the flow of matter in terms of transport or accumulation. The approach was applied to the drainage area of Lake Eckarfjaerden, investigated as part of the site investigation programme at Forsmark in central Sweden. By using data from inlet and outlet of the lake, together with data from the lake itself, we quantified the flow of matter in the drainage area, and also developed mass-balance budgets for important elements. The results were used to validate process oriented terrestrial and aquatic ecosystem models, developed for the same drainage area in parallel to the present study. In conclusion, applying this approach will contribute substantially to our understanding of the processes controlling transport and accumulation of matter in a drainage area, and thereby reduce the uncertainties in estimating radionuclide flow and consequences to humans and the environment. (author)

  13. DETERMINATION OF CHLORINATED ORGANIC COMPOUNDS IN THE MAIN DRAINAGE CHANNEL OF KONYA

    Directory of Open Access Journals (Sweden)

    Mehmet Emin AYDIN

    2000-03-01

    Full Text Available The main drainage channel of Konya collects drainage waters from farmlands of Konya and discharges to the salt lake. Since there is not any city municipal sewarage system in Konya sewage of the city also discharged to the main drainage channel. Along the channel, farmers use the channels water for irrigation purposes. Therefore a through examination of wastewater and determination of chlorinated compounds were necessary. In this research, analyses were carried by gas chromatography (GC on water samples collected hourly, daily and monthly from the channel.

  14. Ecosystem evolution of Lake Gusinoe (Transbaikal region, Russia)

    Energy Technology Data Exchange (ETDEWEB)

    Pisarsky, B.L.; Hardina, A.M.; Naganawa, H. [Russian Academy of Science, Irkutsk (Russian Federation). Siberian Division

    2005-12-01

    Lake Gusinoe is situated on a basin originating from Paleozoic and Mesozoic deposits. The recorded history of the lake's ecosystem evolution is no more than 300 years. The present lake drainage basin was formed mainly in the Cenozoic era, but during the past century, major anthropogenic impacts on the lake have occurred. The human-influenced evolution of the ecosystem began in the 1940s with the development of opencut coal mining nearby the lake. Population increase and the building of the Gusinoozersk State Regional Power Plant, the TransMongolian Railroad and an associated station, and military installations were the major sources of anthropogenic impacts. Since the early 1950s about five species of fish have been introduced into Lake Gusinoe or have invaded the lake, and at least six of the native species have disappeared or are in danger of extinction. From our recent investigations, the present environment of the Lake Gusinoe Basin (Gusinoozersk Basin) is divided into four zones hydro-geochemically: (1) ultrafreshwater, (2) freshwater, (3) mineralized water, and (4) hyposaline and saltwater. Some additional data on changes of the chemical components of the drainage basin waters, as well as on the transition of zooplankton and zoobenthic fauna, are presented in consideration of the risk of industrial development, and the perspectives are discussed.

  15. Regional maximum rainfall analysis using L-moments at the Titicaca Lake drainage, Peru

    Science.gov (United States)

    Fernández-Palomino, Carlos Antonio; Lavado-Casimiro, Waldo Sven

    2017-08-01

    The present study investigates the application of the index flood L-moments-based regional frequency analysis procedure (RFA-LM) to the annual maximum 24-h rainfall (AM) of 33 rainfall gauge stations (RGs) to estimate rainfall quantiles at the Titicaca Lake drainage (TL). The study region was chosen because it is characterised by common floods that affect agricultural production and infrastructure. First, detailed quality analyses and verification of the RFA-LM assumptions were conducted. For this purpose, different tests for outlier verification, homogeneity, stationarity, and serial independence were employed. Then, the application of RFA-LM procedure allowed us to consider the TL as a single, hydrologically homogeneous region, in terms of its maximum rainfall frequency. That is, this region can be modelled by a generalised normal (GNO) distribution, chosen according to the Z test for goodness-of-fit, L-moments (LM) ratio diagram, and an additional evaluation of the precision of the regional growth curve. Due to the low density of RG in the TL, it was important to produce maps of the AM design quantiles estimated using RFA-LM. Therefore, the ordinary Kriging interpolation (OK) technique was used. These maps will be a useful tool for determining the different AM quantiles at any point of interest for hydrologists in the region.

  16. Hydrological network and classification of lakes on the Third Pole

    Science.gov (United States)

    Gao, Yang; Wang, Weicai; Yao, Tandong; Lu, Ning; Lu, Anxin

    2018-05-01

    The intensity and form of changes in closed lakes, upstream lakes and outflow lakes on the Third Pole (TP) differ based on their drainage mode. Researchers' insufficient understanding of the hydrological networks associated with lakes hampers studies of the relationship between lakes and climate. In this study, we establish a comprehensive hydrological network for each lake (>1 km2) on the TP using 106 Landsat images, 236 Chinese topographic maps, and SRTM DEM. Three-hundred-ninety-seven closed lakes, 488 upstream lakes and 317 outflow lakes totaling 3,5498.49 km2, 7,378.82 km2, and 3,382.29 km2, respectively, were identified on the TP using 2010 data. Two-hundred-thirty-four closed lakes were found to not be linked to upstream lakes. The remaining 163 closed lakes were connected to and fed by the 488 upstream lakes. The object-oriented analyses within this study indicated that more rapid changes occurred in the surface extent of closed lakes than in upstream lakes or outflow lakes on the TP from 1970 s to 2010. Furthermore, the water volume of the examined closed lakes was almost nine times greater than that of the upstream lakes from 2003 to 2009. All the examined closed lakes exhibited an obvious water volume change compared to the corresponding upstream lakes in the same basin. Furthermore, two case studies illustrate that the annual and seasonal dynamics associated with the changes in closed lakes may reflect climate change patterns, while the upstream lake dynamics may be more controlled by the lakeshore terrain and drainage characteristics. The lake inventory and hydrological network catalogued in this study provide a basis for developing a better understanding of lake response to climate change on the TP.

  17. Great Lakes

    Science.gov (United States)

    Edsall, Thomas A.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

    1998-01-01

    The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside the floodplain of the river. The region spans about 9º of latitude and 20º of longitude and lies roughly halfway between the equator and the North Pole in a lowland corridor that extends from the Gulf of Mexico to the Arctic Ocean.The Great Lakes are the most prominent natural feature of the region (Fig. 1). They have a combined surface area of about 245,000 square kilometers and are among the largest, deepest lakes in the world. They are the largest single aggregation of fresh water on the planet (excluding the polar ice caps) and are the only glacial feature on Earth visible from the surface of the moon (The Nature Conservancy 1994a).The Great Lakes moderate the region’s climate, which presently ranges from subarctic in the north to humid continental warm in the south (Fig. 2), reflecting the movement of major weather masses from the north and south (U.S. Department of the Interior 1970; Eichenlaub 1979). The lakes act as heat sinks in summer and heat sources in winter and are major reservoirs that help humidify much of the region. They also create local precipitation belts in areas where air masses are pushed across the lakes by prevailing winds, pick up moisture from the lake surface, and then drop that moisture over land on the other side of the lake. The mean annual frost-free period—a general measure of the growing-season length for plants and some cold-blooded animals—varies from 60 days at higher elevations in the north to 160 days in lakeshore areas in the south. The climate influences the general distribution of wild plants and animals in the region and also influences the activities and distribution of the human

  18. Nocturnal drainage wind characteristics in two converging air sheds

    International Nuclear Information System (INIS)

    Gedayloo, T.; Clements, W.E.; Barr, S.; Archuleta, J.A.

    1980-01-01

    During the short experimental period in the Grants Basin of Northeastern New Mexico a survey was conducted on the complex meteorology of this area. Emphasis was placed on the nocturnal drainage flow because of the potential hazards to the populated areas of Milan and Grants from the effluents of the uranium mining and milling operation in this area. This investigation has shown that the nocturnal drainage flow patterns agree with the winds predicted on the basis of the complex terrain of the area. Because of the surface cooling at night (over 25 0 C during summer and about 20 0 C during winter), air from elevated surrounding areas flows to the low lying regions consequently setting up a nocturnal drainage flow. This regime exists over 60% of the time during summer months and over 65% of the time during winter months with a depth generally less than 200 m. In the San Mateo air shed the drainage flow is east northeast, and in the Ambrosia Lake air shed it is from northwest. The confluence of these two air flows contributes mainly to the drainage flow through the channel formed by La Ja Mesa and Mesa Montanosa. The analysis of data collected by the recording Flats Station confirms the prediction that although the area south of the channel region broadens considerably causing a reduction in flow speed, contributions from the southside of La Jara Mesa and Mesa Montanosa partly compensate for this reduction. The position of this recording station is 15 to 20 km from the populated towns of Milan and Grants. A drainage flow speed of approximately 2.2 m s -1 and the duration of over 11 hours as recorded by this station indicates that air from the San Mateo and Ambrosia Lake regions may be transported southwards to these population centers during a nocturnal period. In order to test this prediction, a series of multi-atmospheric tracer experiments were conducted in the Grants Basin

  19. Bathymetric study of the Neotectonic Naini Lake in outer Kumaun Himalaya

    Digital Repository Service at National Institute of Oceanography (India)

    Hashimi, N.H.; Pathak, M.C; Jauhari, P.; Nair, R.R.; Sharma, A.K.; Bhakuni, D.S.; Bisht, M.K.S.; Valdiya, K.S.

    The Naini Lake is a product of rotational movement on a NW-SE trending Nainital Fault, quite after the establishment of the drainage of a mature stream named Balia Nala. Detailed bathymetric study, permits division of this crescent-shaped lake...

  20. Lake acidification in the Adirondack Mountains of New York causes and consequences

    Science.gov (United States)

    Carl L. Schofield

    1976-01-01

    Current and historic geographic distributions of acidity in Adirondack lakes were examined in relation to regional edaphic, climatic, and physiographic features. Acid conditions are currently predominant in high elevation drainage lakes having small watershed/surface area ratios. Comparable levels of acidity were found only in small seepage lakes and bog ponds during...

  1. Towards monitoring surface and subsurface lakes on the Greenland Ice Sheet using Sentinel-1 SAR and Landsat-8 OLI imagery

    Science.gov (United States)

    Miles, Katie E.; Willis, Ian C.; Benedek, Corinne L.; Williamson, Andrew G.; Tedesco, Marco

    2017-07-01

    Supraglacial lakes are an important component of the Greenland Ice Sheet’s mass balance and hydrology, with their drainage affecting ice dynamics. This study uses imagery from the recently launched Sentinel-1A Synthetic Aperture Radar (SAR) satellite to investigate supraglacial lakes in West Greenland. A semi-automated algorithm is developed to detect surface lakes from Sentinel-1 images during the 2015 summer. A combined Landsat-8 and Sentinel-1 dataset, which has a comparable temporal resolution to MODIS (3 days versus daily) but a higher spatial resolution (25-40 m versus 250-500 m), is then used together with a fully-automated lake drainage detection algorithm. Rapid (days) and slow (> 4 days) drainages are investigated for both small (summer. Drainage events of small lakes occur at lower elevations (mean 159 m), and slightly earlier (mean 4.5 days) in the melt season than those of large lakes. The analysis is extended manually into the early winter to calculate the dates and elevations of lake freeze-through more precisely than is possible with optical imagery (mean 30 August; 1270 m mean elevation). Finally, the Sentinel-1 imagery is used to detect subsurface lakes and, for the first time, their dates of appearance and freeze-through (mean 9 August and 7 October, respectively). These subsurface lakes occur at higher elevations than the surface lakes detected in this study (mean 1593 m and 1185 m, respectively). Sentinel-1 imagery therefore provides great potential for tracking melting, water movement and freezing within both the firn zone and ablation area of the Greenland Ice Sheet.

  2. Pleural fluid drainage: Percutaneous catheter drainage versus surgical chest tube drainage

    International Nuclear Information System (INIS)

    Illescas, F.F.; Reinhold, C.; Atri, M.; Bret, P.M.

    1987-01-01

    Over the past 4 years, 55 cases (one transudate, 28 exudates, and 26 empymas) were drained. Surgical chest tubes alone were used in 35 drainages, percutaneous catheters alone in five drainages, and both types in 15 drainages. Percutaneous catheter drainage was successful in 12 of 20 drainages (60%). Surgical tube drainage was successful in 18 of 50 drainages (36%). The success rate for the nonempyema group was 45% with both types of drainage. For the empyema group, the success rate for percutaneous catheter drainage was 66% vs 23% for surgical tube drainage. Seven major complications occurred with surgical tube drainage, but only one major complication occurred with percutaneous catheter drainage. Radiologically guided percutaneous catheter drainage should be the procedure of choice for pleural fluid drainage. It has a higher success rate for empyemas and is associated with less complications

  3. The evolution of a thermokarst-lake landscape: Late Quaternary permafrost degradation and stabilization in interior Alaska

    Science.gov (United States)

    Edwards, Mary E.; Grosse, Guido; Jones, Benjamin M.; McDowell, Patricia F.

    2016-01-01

    Thermokarst processes characterize a variety of ice-rich permafrost terrains and often lead to lake formation. The long-term evolution of thermokarst landscapes and the stability and longevity of lakes depend upon climate, vegetation and ground conditions, including the volume of excess ground ice and its distribution. The current lake status of thermokarst-lake landscapes and their future trajectories under climate warming are better understood in the light of their long-term development. We studied the lake-rich southern marginal upland of the Yukon Flats (northern interior Alaska) using dated lake-sediment cores, observations of river-cut exposures, and remotely-sensed data. The region features thick (up to 40 m) Quaternary deposits (mainly loess) that contain massive ground ice. Two of three studied lakes formed ~ 11,000–12,000 cal yr BP through inferred thermokarst processes, and fire may have played a role in initiating thermokarst development. From ~ 9000 cal yr BP, all lakes exhibited steady sedimentation, and pollen stratigraphies are consistent with regional patterns. The current lake expansion rates are low (0 to drainage, nor of multiple lake generations within a basin. However, LiDAR images reveal linear “corrugations” (> 5 m amplitude), deep thermo-erosional gullies, and features resembling lake drainage channels, suggesting that highly dynamic surface processes have previously shaped the landscape. Evidently, widespread early Holocene permafrost degradation and thermokarst lake initiation were followed by lake longevity and landscape stabilization, the latter possibly related to establishment of dense forest cover. Partial or complete drainage of three lakes in 2013 reveals that there is some contemporary landscape dynamism. Holocene landscape evolution in the study area differs from that described from other thermokarst-affected regions; regional responses to future environmental change may be equally individualistic.

  4. Toward Monitoring Surface and Subsurface Lakes on the Greenland Ice Sheet Using Sentinel-1 SAR and Landsat-8 OLI Imagery

    Directory of Open Access Journals (Sweden)

    Katie E. Miles

    2017-07-01

    Full Text Available Supraglacial lakes are an important component of the Greenland Ice Sheet's mass balance and hydrology, with their drainage affecting ice dynamics. This study uses imagery from the recently launched Sentinel-1A Synthetic Aperture Radar (SAR satellite to investigate supraglacial lakes in West Greenland. A semi-automated algorithm is developed to detect surface lakes from Sentinel-1 images during the 2015 summer. A combined Landsat-8 and Sentinel-1 dataset, which has a comparable temporal resolution to MODIS (3 days vs. daily but a higher spatial resolution (25–40 vs. 250–500 m, is then used together with a fully automated lake drainage detection algorithm. Rapid (<4 days and slow (>4 days drainages are investigated for both small (<0.125 km2, the minimum size detectable by MODIS and large (≥0.125 km2 lakes through the summer. Drainage events of small lakes occur at lower elevations (mean 159 m, and slightly earlier (mean 4.5 days in the melt season than those of large lakes. The analysis is extended manually into the early winter to calculate the dates and elevations of lake freeze-through more precisely than is possible with optical imagery (mean 30 August; 1,270 m mean elevation. Finally, the Sentinel-1 imagery is used to detect subsurface lakes and, for the first time, their dates of appearance and freeze-through (mean 9 August and 7 October, respectively. These subsurface lakes occur at higher elevations than the surface lakes detected in this study (mean 1,593 and 1,185 m, respectively. Sentinel-1 imagery therefore provides great potential for tracking melting, water movement and freezing within both the firn zone and ablation area of the Greenland Ice Sheet.

  5. Contemporary and historical trace metal loadings to the sediments of four lakes of the Lake Washington drainage. Completion report

    International Nuclear Information System (INIS)

    Spyridakis, D.E.; Barnes, R.S.

    1978-01-01

    Contemporary and historical loadings of lead, zinc, and copper to the profundal sediments of Lakes Washington, Sammamish, Chester Morse, and Findley were determined using chemical analysis and 210 Pb dating of sediment cores. Elemental sedimentation rates, a cross product of the sedimentation rate, and sediment concentration of a given element, were corrected for natural background concentrations and rates, and extrapolated across established sediment accumulating areas to give a conservative estimate of the pollutional trace metal loadings to each lake. The resulting chronological loadings appeared consistent with the known cultural history of the individual watersheds. Substantial alterations in sedimentation rates were noted in all lakes where deforestation, road building, suburbanization or urbanization had occurred in the lake's watershed. The quantities, elemental ratios and pollutional histories of copper, lead and zinc in the lake sediments indicate that aeolian inputs are the dominant source of trace metal pollution to the lake sediments at the present time

  6. The Socio-hydrology of Bangalore's Lake System and implications for Urban Water Security

    Science.gov (United States)

    Srinivasan, V.; Roy, S.

    2017-12-01

    Bengaluru city has experienced unprecedented growth in recent decades. If the city is to sustain growth and claim its position as a "global" high-tech city, it must be able to secure sufficient water supply and also create a healthy livable environment. With the city's many lakes vanishing due to rapid urbanisation, depletion of groundwater as a result of overuse in the peri-urban areas, and lack of proper underground drainage system and sewage treatment plants, Bangalore is now grappling with issues of imminent water crisis, inequitable access to water supply, and public health hazards. In this context, the restoration of Bangalore's lakes has been promoted as a panacea for its flooding, water stress, and wastewater problems. It has been argued that lakes can store storm water and recycled wastewater and avoid the need for potentially destructive, expensive schemes that may destroy biodiversity rich aquatic ecosystems and forests. Bangalore's lakes are linked by the drainage channels to form a cascade; overflow from each lake flows to the next lake downstream. Yet, most efforts have tended to view the lakes in isolation. This study of the hydrology of Bangalore's lake system in its entirety simulates the lake system as a whole. The study explores approaches to management and theor impact on urban water security.

  7. Siderite formation in mining lakes. Sanitation strategy for the Spreetal Nordost lake; Sideritbildung in Tagebaurestseen. Moegliche Sanierungsstrategie des Restlochs Spreetal Nordost

    Energy Technology Data Exchange (ETDEWEB)

    Unger, Y.; Wolkersdorfer, C. [Technische Univ. Bergakademie Freiberg (Germany)

    2006-07-01

    The treatment of acid mine lakes is a worldwide problem. In this study, it will be investigated since the sludge from acid mine drainage (AMD) treatment plants combined with carbon dioxide injections may improve the water quality in such pit lakes. Simultaneously, the emissions of carbon dioxide into the atmosphere may be reduced. The CO{sub 2} will be sequestered in the lake sediments as siderite (FeCO{sub 3}). The acid mine lake Spreetal-Nordost (Lusatia/Germany) was chosen as a test site. Since 1998 iron hydroxide sludge from an AMD treatment plant was deposited into the lake. In preliminary tests the feasibility of this treatment scheme will be investigated. (orig.)

  8. Geomorphic Drainage Capture Recorded by Oxygen Isotopes of Green River Formation Lacustrine Mudstone, Eocene, Wyoming

    Science.gov (United States)

    Doebbert, A. C.; Booth, A. L.; Carroll, A.; Chamberlain, C.; Rhodes, M.

    2005-12-01

    The isotopic composition of cement and other meteoric precipitates are increasingly being used to interpret orogenic uplift histories, based on the relationship between altitude and rainwater δ18O. However, other variables such as changing regional drainage patterns may also affect the downstream composition of surface waters, especially when multiple drainages commingle in a lake. The Green River Formation contains some of the best documented lacustrine deposits in the world, making it ideal for examining such issues. Carbonate mudstone in balanced-fill facies of the lower LaClede Bed averages 3.41‰ (PDB), and records a deep, saline to brackish lake that fluctuated near its sill. In contrast, overfilled facies of the upper LaClede Bed record a freshwater lake, and δ18O reaches values as low as -9.72‰. This transition occurred shortly after deposition of the Analcite Tuff at 48.94 ± 0.12 Ma (Smith et al., 2003), and was geologically abrupt. Based on 40Ar/39Ar-calibrated sediment accumulation rates it required no more than 200-300 ky. An almost identical transition occurs in two cores separated by about 30 km, making local diagenesis an unlikely cause. The magnitude of δ18O change is similar to that in some uplift studies, but its rapidity virtually excludes uplift as a controlling mechanism. Instead, we propose that both the change in sedimentation and the sharp decrease in δ18O are the result of a drainage capture event. The addition of a new drainage to the basin may have adjusted isotopic values in two ways: by introducing runoff with relatively low δ18O, and by decreasing residence time (and therefore evaporation) of lake water. Decreasing 87Sr/86Sr across the same transition suggests that the newly added waters may have been sourced from rising volcanic topography to the north in the Absaroka province. Although this rising topography allows for the possibility of some uplift component, the rate of change in lacustrine δ18O is consistent with

  9. Pluvial lakes in the Great Basin of the western United States: a view from the outcrop

    Science.gov (United States)

    Reheis, Marith C.; Adams, Kenneth D.; Oviatt, Charles G.; Bacon, Steven N.

    2014-01-01

    Paleo-lakes in the western United States provide geomorphic and hydrologic records of climate and drainage-basin change at multiple time scales extending back to the Miocene. Recent reviews and studies of paleo-lake records have focused on interpretations of proxies in lake sediment cores from the northern and central parts of the Great Basin. In this review, emphasis is placed on equally important studies of lake history during the past ∼30 years that were derived from outcrop exposures and geomorphology, in some cases combined with cores. Outcrop and core records have different strengths and weaknesses that must be recognized and exploited in the interpretation of paleohydrology and paleoclimate. Outcrops and landforms can yield direct evidence of lake level, facies changes that record details of lake-level fluctuations, and geologic events such as catastrophic floods, drainage-basin changes, and isostatic rebound. Cores can potentially yield continuous records when sampled in stable parts of lake basins and can provide proxies for changes in lake level, water temperature and chemistry, and ecological conditions in the surrounding landscape. However, proxies such as stable isotopes may be influenced by several competing factors the relative effects of which may be difficult to assess, and interpretations may be confounded by geologic events within the drainage basin that were unrecorded or not recognized in a core. The best evidence for documenting absolute lake-level changes lies within the shore, nearshore, and deltaic sediments that were deposited across piedmonts and at the mouths of streams as lake level rose and fell. We review the different shorezone environments and resulting deposits used in such reconstructions and discuss potential estimation errors. Lake-level studies based on deposits and landforms have provided paleohydrologic records ranging from general changes during the past million years to centennial-scale details of fluctuations during the

  10. MERGANSER - A Predictive Model of Mercury in Fish and Loons in New England Lakes

    Science.gov (United States)

    Moore, R. B.; Shanley, J. B.; Smith, R. A.; Miller, E. K.; Simcox, A.; Kamman, N. C.; Nacci, D. E.; Robinson, K. W.; Johnston, J. M.; Hughes, M.; Johnston, C. M.; Williams, K.; Graham, J.; King, S.

    2010-12-01

    MERGANSER (MERcury Geo-spatial AssessmeNtS for the New England Region) is an empirical least squares multiple regression model using atmospheric deposition of mercury (Hg) and readily obtainable lake and watershed features to predict fish and common loon Hg in New England lakes. We modeled lakes larger than 8 ha and with drainage area completely within the USA (4404 lakes), using 3827 fish (12 species) and loon Hg values from 420 lakes. MERGANSER predictor variables included Hg deposition, watershed alkalinity, percent wetlands, percent forest canopy, percent agriculture, drainage area, population, mean annual temperature and watershed slope. The model returns fish tissue or loon blood Hg for user-entered species and length. MERGANSER explained 63% of the variance in fish fillet and loon Hg concentrations. MERGANSER predicted that 32-cm small mouth bass had a median Hg concentration of 0.53 µg g-1 and exceeded EPA’s maximum contaminant level (MCL) of 0.3 µg/g Hg in 90% of New England lakes. Common loon had a median Hg concentration of 1.07 µg g-1 and was in the moderate or higher risk category of >1 µg/g Hg in 58% of New England lakes.

  11. Structure and evolution of the drainage system of a Himalayan debris-covered glacier, and its relationship with patterns of mass loss

    Science.gov (United States)

    Benn, Douglas I.; Thompson, Sarah; Gulley, Jason; Mertes, Jordan; Luckman, Adrian; Nicholson, Lindsey

    2017-09-01

    We provide the first synoptic view of the drainage system of a Himalayan debris-covered glacier and its evolution through time, based on speleological exploration and satellite image analysis of Ngozumpa Glacier, Nepal. The drainage system has several linked components: (1) a seasonal subglacial drainage system below the upper ablation zone; (2) supraglacial channels, allowing efficient meltwater transport across parts of the upper ablation zone; (3) sub-marginal channels, allowing long-distance transport of meltwater; (4) perched ponds, which intermittently store meltwater prior to evacuation via the englacial drainage system; (5) englacial cut-and-closure conduits, which may undergo repeated cycles of abandonment and reactivation; and (6) a "base-level" lake system (Spillway Lake) dammed behind the terminal moraine. The distribution and relative importance of these elements has evolved through time, in response to sustained negative mass balance. The area occupied by perched ponds has expanded upglacier at the expense of supraglacial channels, and Spillway Lake has grown as more of the glacier surface ablates to base level. Subsurface processes play a governing role in creating, maintaining, and shutting down exposures of ice at the glacier surface, with a major impact on spatial patterns and rates of surface mass loss. Comparison of our results with observations on other glaciers indicate that englacial drainage systems play a key role in the response of debris-covered glaciers to sustained periods of negative mass balance.

  12. Surface runoff and tile drainage transport of phosphorus in the midwestern United States.

    Science.gov (United States)

    Smith, Douglas R; King, Kevin W; Johnson, Laura; Francesconi, Wendy; Richards, Pete; Baker, Dave; Sharpley, Andrew N

    2015-03-01

    The midwestern United States offers some of the most productive agricultural soils in the world. Given the cool humid climate, much of the region would not be able to support agriculture without subsurface (tile) drainage because high water tables may damage crops and prevent machinery usage in fields at critical times. Although drainage is designed to remove excess soil water as quickly as possible, it can also rapidly transport agrochemicals, including phosphorus (P). This paper illustrates the potential importance of tile drainage for P transport throughout the midwestern United States. Surface runoff and tile drainage from fields in the St. Joseph River Watershed in northeastern Indiana have been monitored since 2008. Although the traditional concept of tile drainage has been that it slowly removes soil matrix flow, peak tile discharge occurred at the same time as peak surface runoff, which demonstrates a strong surface connection through macropore flow. On our research fields, 49% of soluble P and 48% of total P losses occurred via tile discharge. Edge-of-field soluble P and total P areal loads often exceeded watershed-scale areal loadings from the Maumee River, the primary source of nutrients to the western basin of Lake Erie, where algal blooms have been a pervasive problem for the last 10 yr. As farmers, researchers, and policymakers search for treatments to reduce P loading to surface waters, the present work demonstrates that treating only surface runoff may not be sufficient to reach the goal of 41% reduction in P loading for the Lake Erie Basin. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  13. Regional-scale analysis of lake outburst hazards in the southwestern Pamir, Tajikistan, based on remote sensing and GIS

    Directory of Open Access Journals (Sweden)

    M. Mergili

    2011-05-01

    Full Text Available This paper presents an analysis of the hazards emanating from the sudden drainage of alpine lakes in South-Western Tajik Pamir. In the last 40 yr, several new lakes have formed in the front of retreating glacier tongues, and existing lakes have grown. Other lakes are dammed by landslide deposits or older moraines. In 2002, sudden drainage of a glacial lake in the area triggered a catastrophic debris flow. Building on existing approaches, a rating scheme was devised allowing quick, regional-scale identification of potentially hazardous lakes and possible impact areas. This approach relies on GIS, remote sensing and empirical modelling, largely based on medium-resolution international datasets. Out of the 428 lakes mapped in the area, 6 were rated very hazardous and 34 hazardous. This classification was used for the selection of lakes requiring in-depth investigation. Selected cases are presented and discussed in order to understand the potentials and limitations of the approach used. Such an understanding is essential for the appropriate application of the methodology for risk mitigation purposes.

  14. Hydrogeological and geochemical studies in the Perch Lake basin

    International Nuclear Information System (INIS)

    Barry, P.J.

    1979-08-01

    The Perch Lake basin is a small drainage system along the Ottawa River about 200 km west of Ottawa on the Canadian Shield. Since 1975, groups of scientists from several Canadian universities and government departments have been studying the hydrological, geological and geochemical properties of the basin. The object of these studies is to develop and test simulation models used to describe the time-dependent mass flow rates of water and dissolved and suspended substances through the basin. To review progress, a symposium/workshop was held at Chalk Rier in 1978 April. This report contains 24 extended summaries of the material presented verbally at the workshop. Subject matters include atmospheric sources and sinks, mass flows through the surface and subsurface regimes in the drainage basins and interactions occurring in the lake. (author)

  15. Environmental status of the Lake Michigan region. Volume 14. Birds of the Lake Michigan drainage basin

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, G.J.

    1977-07-01

    This report characterizes the bird life found in 100 counties of the four states peripheral to Lake Michigan. It discusses major habitats (the Lake Michigan shoreline, inland lakes, rivers and streams, marshes, fields and open spaces, and woodlots) and associates specific birds with habitats according to preferences for space and food. It also discusses the special attributes of state parks and lakeshores, refuges and sanctuaries, and other special areas which are attractive to avifauna. Patterns of historical occurrence and abundance, and the influence of pesticides and pollution, disease, and hunting pressure are explored to place present occurrence in a modern perspective. Migration patterns are discussed to explain increases and decreases which occur in nonresident avifauna of the Basin. The distribution and habits of birds that occur regularly in the Basin are described in an annotated list; a more complete list is presented in a table which encapsulates data for rapid and convenient reference. Separate sections deal with extinct, extirpated, and introduced species, and with endangered, threatened, and declining species.

  16. The effect of climatic changes on Van lake

    International Nuclear Information System (INIS)

    Dirican, A.

    2002-01-01

    Lake levels are influenced by climatic changes, greenhouse effects and anthropogenic activities. These effects are reflected in the hydrological cycle features over the lake drainage basins. Among the significant hydrological variables, lake levels are influenced by different atmospheric and environmental conditions. During wet periods, there may be water-level rise that may cause some social and economical losses to agriculture and human activities along the lake shores. Such rises become serious in the case of shore line settlements and low lying agricultural land. Lake Van currently faces such problems due to water-level rises in eastern Turkey. Because of, it is a closed basin with no natural and artificial outlet and its water contain high concentrations of soda which prevent the use of its water as a drinking or agricultural water source, Lake Van unique. Under these circumstances, in addition to discussion of early studies air temperature, δ 18 O of precipitation, temperature profile of lake and δ 18 O variation of water column of lake Van were examined

  17. Water-quality and sediment-chemistry data of drain water and evaporation ponds from Tulare Lake Drainage District, Kings County, California March 1985 to March 1986

    Science.gov (United States)

    Fujii, Roger

    1988-01-01

    Trace element and major ion concentrations were measured in water samples collected monthly between March 1985 and March 1986 at the MD-1 pumping station at the Tulare Lake Drainage District evaporation ponds, Kings County, California. Samples were analyzed for selected pesticides several times during the year. Salinity, as measured by specific conductance, ranged from 11,500 to 37,600 microsiemens/centimeter; total recoverable boron ranged from 4,000 to 16,000 micrg/L; and total recoverable molybdenum ranged from 630 to 2,600 microg/L. Median concentrations of total arsenic and total selenium were 97 and 2 microg/L. Atrazine, prometone, propazine, and simazine were the only pesticides detected in water samples collected at the MD-1 pumping station. Major ions, trace elements, and selected pesticides also were analyzed in water and bottom-sediment samples from five of the southern evaporation ponds at Tulare Lake Drainage District. Water enters the ponds from the MD-1 pumping station at pond 1 and flows through the system terminating at pond 10. The water samples increased in specific conductance (21,700 to 90,200 microsiemens/centimeter) and concentrations of total arsenic (110 to 420 microg/L), total recoverable boron (12,000 to 80,000 microg/L) and total recoverable molybdenum (1,200 to 5,500 microg/L) going from pond 1 to pond 10, respectively. Pesticides were not detected in water from any of the ponds sampled. Median concentrations of total arsenic and total selenium in the bottom sediments were 4.0 and 0.9 microg/g, respectively. The only pesticides detected in bottom sediment samples from the evaporation ponds were DDD and DDE, with maximum concentration of 0.8 microg/kilogram. (Author 's abstract)

  18. Lake Austin uranium deposit, Western Australia

    International Nuclear Information System (INIS)

    Heath, A.G.; Deutscher, R.L.; Butt, C.R.M.

    1984-01-01

    The Lake Austin uranium deposit is a calcrete type deposit in the Yilgarn Block, near Cue, in a catchment area of granitoids and greenstones. The uranium is in valley fill and the sediments of the Lake Austin playa. The mineralization occurs over 1 to 6 meter thickness close to the water table in calcrete overlying clays and/or weathered bedrock. The principal uranium mineral is carnotite. Waters in nearby channels have an uranium content of over 30 ppb. The chloride content of the water increases downstream in the nearby drainages, as does the uranium and vanadium content. (author)

  19. Delineation of a Re-establishing Drainage Network Using SPOT and Landsat Images

    Science.gov (United States)

    Bailey, J. E.; Self, S.; Mouginis-Mark, P. J.

    2008-12-01

    The 1991 eruption of Mt. Pinatubo, The Philippines, provided a unique opportunity to study the effects on the landscape of a large eruption in part because it took place after the advent of regular satellite-based observations. The eruption formed one large (>100km2) ignimbrite sheet, with over 70% of the total deposit deposited in three primary drainage basins to the west of the volcano. High-resolution (20 m/pixel) satellite images, showing the western drainage basins and surrounding region both before and after the eruption were used to observe the re-establishment and evolution of drainage networks on the newly emplaced ignimbrite sheet. Changes in the drainage networks were delineated from a time series of SPOT (Satellite Pour l'Observation de la Terre) and Landsat multi-spectral satellite images. The analysis of which was supplemented by ground- based observations. The satellite images showed that the blue prints for the new drainage systems were established early (within days of the eruption) and at a large-scale followed the pre-eruption pattern. However, the images also illustrated the ephemeral nature of many channels due to the influence of secondary pyroclastic flows, lahar- dammed lake breakouts, stream piracy and shifts due to erosion. Characteristics of the defined drainage networks were used to infer the relative influence on the lahar hazard within each drainage basin.

  20. The Elevation to Area Relationship of Lake Behnke

    Directory of Open Access Journals (Sweden)

    Kaitlin Deutsch

    2012-01-01

    Full Text Available The objective of this project was to determine the area-to-depth relationship in Lake Behnke, which acts as the principal stormwater drainage basin for the University of South Florida campus in Tampa, Florida. Data previously collected in a stormwater management study by Jeffery Earhart illustrated a linear correlation between the lake's area and depth; however, that study was conducted in 1998, and this present work serves to double check that correlation. We analyzed a bathymetric map of Lake Behnke that displayed several contour lines indicating depth and approximated the area inside each closed curve with a contour integral. The resulting relationship between area and elevation was determined to be more parabolic than linear.

  1. Holocene evolution of lakes in the forest-tundra biome of northern Manitoba, Canada

    Science.gov (United States)

    Hobbs, William O.; Edlund, Mark B.; Umbanhowar, Charles E.; Camill, Philip; Lynch, Jason A.; Geiss, Christoph; Stefanova, Vania

    2017-03-01

    The late-Quaternary paleoenvironmental history of the western Hudson Bay region of Subarctic Canada is poorly constrained. Here, we present a regional overview of the post-glacial history of eight lakes which span the forest-tundra biome in northern Manitoba. We show that during the penultimate drainage phase of Lake Agassiz the lake water had an estimated pH of ∼6.0, with abundant quillwort (Isöetes spp.) along the lakeshore and littoral zone and some floating green algae (Botryococcus spp. and Pediastrum sp.). Based on multiple sediment proxies, modern lake ontogeny in the region commenced at ∼7500 cal yrs BP. Pioneering diatom communities were shaped by the turbid, higher alkalinity lake waters which were influenced by base cation weathering of the surrounding till following Lake Agassiz drainage. By ∼7000 cal yrs BP, soil development and Picea spp. establish and the lakes began a slow trajectory of acidification over the remaining Holocene epoch. The natural acidification of the lakes in this region is slow, on the order of several millennia for one pH unit. Each of the study lakes exhibit relatively stable aquatic communities during the Holocene Thermal Maximum, suggesting this period is a poor analogue for modern climatic changes. During the Neoglacial, the beginning of the post-Little Ice Age period represents the most significant climatic event to impact the lakes of N. Manitoba. In the context of regional lake histories, the rate of diatom floristic change in the last 200-300 years is unprecedented, with the exception of post-glacial lake ontogeny in some of the lakes. For nearly the entire history of the lakes in this region, there is a strong linkage between landscape development and the aquatic ecosystems; however this relationship appears to become decoupled or less strong in the post-LIA period. Significant 20th century changes in the aquatic ecosystem cannot be explained wholly by changes in the terrestrial ecosystem, suggesting that future

  2. Local response of a glacier to annual filling and drainage of an ice-marginal lake

    Science.gov (United States)

    Walder, J.S.; Trabant, D.C.; Cunico, M.; Fountain, A.G.; Anderson, S.P.; Anderson, R. Scott; Malm, A.

    2006-01-01

    Ice-marginal Hidden Creek Lake, Alaska, USA, outbursts annually over the course of 2-3 days. As the lake fills, survey targets on the surface of the 'ice dam' (the glacier adjacent to the lake) move obliquely to the ice margin and rise substantially. As the lake drains, ice motion speeds up, becomes nearly perpendicular to the face of the ice dam, and the ice surface drops. Vertical movement of the ice dam probably reflects growth and decay of a wedge of water beneath the ice dam, in line with established ideas about jo??kulhlaup mechanics. However, the distribution of vertical ice movement, with a narrow (50-100 m wide) zone where the uplift rate decreases by 90%, cannot be explained by invoking flexure of the ice dam in a fashion analogous to tidal flexure of a floating glacier tongue or ice shelf. Rather, the zone of large uplift-rate gradient is a fault zone: ice-dam deformation is dominated by movement along high-angle faults that cut the ice dam through its entire thickness, with the sense of fault slip reversing as the lake drains. Survey targets spanning the zone of steep uplift gradient move relative to one another in a nearly reversible fashion as the lake fills and drains. The horizontal strain rate also undergoes a reversal across this zone, being compressional as the lake fills, but extensional as the lake drains. Frictional resistance to fault-block motion probably accounts for the fact that lake level falls measurably before the onset of accelerated horizontal motion and vertical downdrop. As the overall fault pattern is the same from year to year, even though ice is lost by calving, the faults must be regularly regenerated, probably by linkage of surface and bottom crevasses as ice is advected toward the lake basin.

  3. Fault-dominated deformation in an ice dam during annual filling and drainage of a marginal lake

    Science.gov (United States)

    Walder, J.S.; Trabant, D.C.; Cunico, M.; Anderson, S.P.; Anderson, R. Scott; Fountain, A.G.; Malm, A.

    2005-01-01

    Ice-dammed Hidden Creek Lake, Alaska, USA, outbursts annually in about 2-3 days. As the lake fills, a wedge of water penetrates beneath the glacier, and the surface of this 'ice dam' rises; the surface then falls as the lake drains. Detailed optical surveying of the glacier near the lake allows characterization of ice-dam deformation. Surface uplift rate is close to the rate of lake-level rise within about 400 m of the lake, then decreases by 90% over about 100 m. Such a steep gradient in uplift rate cannot be explained in terms of ice-dam flexure. Moreover, survey targets spanning the zone of steep uplift gradient move relative to one another in a nearly reversible fashion as the lake fills and drains. Evidently, the zone of steep uplift gradient is a fault zone, with the faults penetrating the entire thickness of the ice dam. Fault motion is in a reverse sense as the lake fills, but in a normal sense as the lake drains. As the overall fault pattern is the same from year to year, even though ice is lost by calving, the faults must be regularly regenerated, probably by linkage of surface and bottom crevasses as ice is advected toward the lake basin.

  4. Occurrence of and trends in selected sediment-associated contaminants in Caddo Lake, East Texas, 1940-2002

    Science.gov (United States)

    Wilson, Jennifer T.

    2003-01-01

    Bottom-sediment cores were collected from four sites in Caddo Lake in East Texas during May 2002 for analyses of radionuclides (for age dating), organochlorine pesticides, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and major and trace elements, and to describe the occurrence and trends of these sediment-associated contaminants. The Goose Prairie Creek and Harrison Bayou sites receive drainage from an area that includes parts of the now-closed Longhorn Army Ammunitions Plant. The mid-lake site is relatively close to dense oil and gas operations in the lake. The Carter Lake site receives minimal discharge from developed areas. Sediment age (deposition) dates represented in the cores ranged from 1940 to 2002. The only organochlorine compounds detected in all core samples were the DDT degradation products DDE or DDD, and PCB Aroclors 1242, 1254, and 1260 were detected only at the Goose Prairie Creek site. One or more of the DDE concentrations at all sites exceeded a consensus-based threshold effect concentration (on benthic biota), but none exceeded a consensus-based probable effect concentration. The Goose Prairie Creek site had significant downward trends in concentrations of organochlorine compounds, except for no trend in DDE concentrations. The Ammunitions Plant is a possible historical source of the few organochlorine compounds detected at the Goose Prairie Creek and Harrison Bayou sites. PAH concentrations at all sites were below respective threshold effect concentrations. Highest PAH concentrations at all four sites were of C2- alkylated naphthalenes. Nearly all statistically significant PAH trends in the cores were downward. On the basis of PAH source-indicator ratios, the majority of PAH compounds appear to have originated from uncombusted sources such as leaks or spills from oil and gas operations or vehicles (automobiles, boats, aircraft) in the Caddo Lake area. Concentrations of several of the eight trace elements with

  5. Response of the St. Joseph River to lake level changes during the last 12,000 years in the Lake Michigan basin

    Science.gov (United States)

    Kincare, K.A.

    2007-01-01

    The water level of the Lake Michigan basin is currently 177 m above sea level. Around 9,800 14C years B.P., the lake level in the Lake Michigan basin had dropped to its lowest level in prehistory, about 70 m above sea level. This low level (Lake Chippewa) had profound effects on the rivers flowing directly into the basin. Recent studies of the St. Joseph River indicate that the extreme low lake level rejuvenated the river, causing massive incision of up to 43 m in a valley no more than 1.6 km wide. The incision is seen 25 km upstream of the present shoreline. As lake level rose from the Chippewa low, the St. Joseph River lost competence and its estuary migrated back upstream. Floodplain and channel sediments partially refilled the recently excavated valley leaving a distinctly non-classical morphology of steep sides with a broad, flat bottom. The valley walls of the lower St. Joseph River are 12-18 m tall and borings reveal up to 30 m of infill sediment below the modern floodplain. About 3 ?? 108 m3 of sediment was removed from the St. Joseph River valley during the Chippewa phase lowstand, a massive volume, some of which likely resides in a lowstand delta approximately 30 km off-shore in Lake Michigan. The active floodplain below Niles, Michigan, is inset into an upper terrace and delta graded to the Calumet level (189 m) of Lake Chicago. In the lower portion of the terrace stratigraphy a 1.5-2.0 m thick section of clast-supported gravel marks the entry of the main St. Joseph River drainage above South Bend, Indiana, into the Lake Michigan basin. This gravel layer represents the consolidation of drainage that probably occurred during final melting out of ice-marginal kettle chains allowing stream piracy to proceed between Niles and South Bend. It is unlikely that the St. Joseph River is palimpsest upon a bedrock valley. The landform it cuts across is a glaciofluvial-deltaic feature rather than a classic unsorted moraine that would drape over pre-glacial topography

  6. Joint Geodetic and Seismic Analysis of the effects of Englacial and Subglacial Hydraulics on Surface Crevassing near a Seasonal, Glacier-Dammed Lake on Gornergletscher, Switzerland

    Science.gov (United States)

    Garcia, L.; Luttrell, K. M.; Kilb, D. L.; Walter, F.

    2017-12-01

    Glacial outburst floods are difficult to predict and threaten human life and property near glaciated regions. These events are characterized by rapid draining of glacier-dammed lakes via the sub/englacial hydraulic network to the proglacial stream. The glacier-dammed lake on Gornergletscher in Switzerland, which fills and drains each summer, provides an opportunity to study this hazard. For three drainages (2004, 2006, and 2007), we track icequakes (IQ) and on-ice GPS movement. Our seasonal seismic networks had 8 - 24 three component stations and apertures of about 300 - 400 m on the glacier surface. The seasonal GPS arrays contained 4 - 8 GPS antennae on the glacier surface. Using Rayleigh wave coherence surface IQ location, we located 2924, 7822 and 3782 IQs, in 2004, 2006 and 2007, respectively. The GPS data were smoothed using a nonparametric protocol, with average station velocities of 10 - 90 mm/day. In 2006, strains were calculated using five stations within 500 m of the lake, co-located with the seismic network. IQ productivity increased substantially during lake drainage only in 2004, which was the only year when the lake drainage was rapid ( 6 days) and primarily subglacial. In 2006, there was no obvious increase in GPS speeds with slow ( 21 days), supraglacial lake drainage. However, when drainage was subglacial as in 2004 and 2007 (sub/englacial over 11 days), GPS speed increased up to 160%. This speed increase is evidence for basal sliding induced by subglacial drainage. In general, we find that when the strain increase on the principle extension axis aligns with the crevasse opening direction, IQ are more prolific. We also observe a diurnal signal in both IQ occurrence and surface strain, with peak strain occurring in the mid- to late-afternoon (15:00 - 19:00 local) across the study area in 2006. We interpret this time-shift in strain and spatiotemporal dependence of IQs to be caused by diurnal variations in melt-induced sliding. Our analysis sheds

  7. Impacts of Climate Change on Tibetan Lakes: Patterns and Processes

    Directory of Open Access Journals (Sweden)

    Dehua Mao

    2018-02-01

    Full Text Available High-altitude inland-drainage lakes on the Tibetan Plateau (TP, the earth’s third pole, are very sensitive to climate change. Tibetan lakes are important natural resources with important religious, historical, and cultural significance. However, the spatial patterns and processes controlling the impacts of climate and associated changes on Tibetan lakes are largely unknown. This study used long time series and multi-temporal Landsat imagery to map the patterns of Tibetan lakes and glaciers in 1977, 1990, 2000, and 2014, and further to assess the spatiotemporal changes of lakes and glaciers in 17 TP watersheds between 1977 and 2014. Spatially variable changes in lake and glacier area as well as climatic factors were analyzed. We identified four modes of lake change in response to climate and associated changes. Lake expansion was predominantly attributed to increased precipitation and glacier melting, whereas lake shrinkage was a main consequence of a drier climate or permafrost degradation. These findings shed new light on the impacts of recent environmental changes on Tibetan lakes. They suggest that protecting these high-altitude lakes in the face of further environmental change will require spatially variable policies and management measures.

  8. Spatial dynamics of thermokarst and thermo-erosion at lakes and ponds in North Siberia and Northwest Alaska using high-resolution remote sensing

    Science.gov (United States)

    Grosse, G.; Tillapaugh, M.; Romanovsky, V. E.; Walter, K. M.; Plug, L. J.

    2008-12-01

    Formation, growth, and drainage of thermokarst lakes in ice-rich permafrost deposits are important factors of landscape dynamics in extent Arctic lowlands. Monitoring of spatial and temporal dynamics of such lakes will allow an assessment of permafrost stability and enhance the capabilities for modelling and quantifying biogeochemical processes related to permafrost degradation in a warming Arctic. In this study we use high-resolution remote sensing and GIS to analyze the development of thermokarst lakes and ponds in two study regions in North Siberia and Northwest Alaska. The sites are 1) the Cherskii region in the Kolyma lowland (Siberia) and 2) the Kitluk River area on the northern Seward Peninsula (Alaska). Both regions are characterized by continuous permafrost, a highly dissected and dynamic thermokarst landscape, uplands of Late Pleistocene permafrost deposits with high excess ice contents, and a large total volume of permafrost-stored carbon. These ice-rich Yedoma or Yedoma-like deposits are highly vulnerable to permafrost degradation forced by climate warming or other surface disturbance. Time series of high- resolution imagery (aerial, Corona, Ikonos, Alos Prism) covering more than 50 years of lake dynamics allow detailed assessments of processes and spatial patterns of thermokarst lake expansion and drainage in continuous permafrost. Time series of high-resolution imagery (aerial, Corona, Ikonos, Alos Prism) covering more than 50 years of lake dynamics allow detailed assessments of processes and spatial patterns of thermokarst lake expansion and drainage in continuous permafrost. Processes identified include thaw slumping, wave undercutting of frozen sediments or peat blocks and subsequent mass wasting, thaw collapse of near-shore zones, sinkhole formation and ice-wedge tunnelling, and gully formation by thermo-erosion. We use GIS-based tools to relate the remote sensing results to field data (ground ice content, topography, lithology, and relative age

  9. BATHYMETRIC STUDY OF WADI EL-RAYAN LAKES, EGYPT

    Directory of Open Access Journals (Sweden)

    Radwan Gad Elrab ABD ELLAH

    2016-12-01

    Full Text Available Bathymetry is a technique of measuring depths to determine the morphometry of water bodies. The derivation of bathymetry from the surveys is one of the basic researches of the aquatic environment, which has several practical implications to on the lake environment and it's monitoring. Wadi El-Rayan, as Ramsar site, is a very important wetland, in Egypt, as a reservoir for agricultural drainage water, fisheries and tourism. The Lakes are man-made basins in the Fayoum depression. Wadi El-Rayan Lakes are two reservoirs (upper Lake and Lower Lake, at different elevations. The Upper Lake is classified as open basin, while the Lower Lake is a closed basin, with no significant obvious water outflow. During recent decades, human impact on Wadi El-Rayan Lakes has increased due to intensification of agriculture and fish farming. Analyses of bathyemtric plans from 1996, 2010 and 2016 showed, the differences between morphometric parameters of the Upper Lake were generally small, while the Lower Lake changes are obvious at the three periods. The small fluctuate, in the features of Upper Lake is due to the water balance between the water inflow and water. The Lower Lake has faced extreme water loss through last twenty years is due to the agricultural lands and fish farms extended in the depression. The Upper Lake is rich in Lakeshores macrophyets, while decline the water plants in the Lower Lake. With low water levels, in the Lower Lake, the future continuity of the Lake system is in jeopardy

  10. Barcoding of ancient lake ostracods (crustacea reveals cryptic speciation with extremely low distances.

    Directory of Open Access Journals (Sweden)

    Ivana Karanovic

    Full Text Available Ostracods are drastically reduced crustaceans, with never more than eight appendages enclosed between two valves, leaving only a limited number of morphological characters for species delineation. Conservative morphology of characters used to define genera, along with high variability of characters used to define species are creating problems in applying a morphospecies concept. A high intraspecific variability in a Lake Biwa (Japan endemic, Physocypria biwaensis (Okubo, 1990, has been observed previously but was never studied in detail. Two sympatric forms, differing in pigmentation and size, suggest a presence of reproductive isolation. The aim of this study is to employ molecular and morphometric tools to aid in species delineation within P. biwaensis complex and reconstruct their phylogenetic relationships. A fragment of the mtCOI gene was amplified from 30 specimens, and an additional 37 specimens were studied for morphological characters. Resulting phylogenies showed that each morphologically distinct form is associated with a distinct phylogenetic group based on mtDNA. The average pairwise distance is very low (5%, indicating a recent divergence time. I speculate that there is a possibility that one of them originated in the lake, while the other probably colonized it afterwards. This seems to be supported with an apparent niche partitioning at different depths. In spite of the fact that traditionally used sexual characters are highly variable in these two species, the morphometric analysis of shell and soft part related characters clearly delineates them and suggests that such characters may be useful for future detection of seemingly cryptic ostracod species.

  11. Structure and evolution of the drainage system of a Himalayan debris-covered glacier, and its relationship with patterns of mass loss

    Directory of Open Access Journals (Sweden)

    D. I. Benn

    2017-09-01

    Full Text Available We provide the first synoptic view of the drainage system of a Himalayan debris-covered glacier and its evolution through time, based on speleological exploration and satellite image analysis of Ngozumpa Glacier, Nepal. The drainage system has several linked components: (1 a seasonal subglacial drainage system below the upper ablation zone; (2 supraglacial channels, allowing efficient meltwater transport across parts of the upper ablation zone; (3 sub-marginal channels, allowing long-distance transport of meltwater; (4 perched ponds, which intermittently store meltwater prior to evacuation via the englacial drainage system; (5 englacial cut-and-closure conduits, which may undergo repeated cycles of abandonment and reactivation; and (6 a "base-level" lake system (Spillway Lake dammed behind the terminal moraine. The distribution and relative importance of these elements has evolved through time, in response to sustained negative mass balance. The area occupied by perched ponds has expanded upglacier at the expense of supraglacial channels, and Spillway Lake has grown as more of the glacier surface ablates to base level. Subsurface processes play a governing role in creating, maintaining, and shutting down exposures of ice at the glacier surface, with a major impact on spatial patterns and rates of surface mass loss. Comparison of our results with observations on other glaciers indicate that englacial drainage systems play a key role in the response of debris-covered glaciers to sustained periods of negative mass balance.

  12. Geology and geomorphology of Bear Lake Valley and upper Bear River, Utah and Idaho

    Science.gov (United States)

    Reheis, M.C.; Laabs, B.J.C.; Kaufman, D.S.

    2009-01-01

    Bear Lake, on the Idaho-Utah border, lies in a fault-bounded valley through which the Bear River flows en route to the Great Salt Lake. Surficial deposits in the Bear Lake drainage basin provide a geologic context for interpretation of cores from Bear Lake deposits. In addition to groundwater discharge, Bear Lake received water and sediment from its own small drainage basin and sometimes from the Bear River and its glaciated headwaters. The lake basin interacts with the river in complex ways that are modulated by climatically induced lake-level changes, by the distribution of active Quaternary faults, and by the migration of the river across its fluvial fan north of the present lake. The upper Bear River flows northward for ???150 km from its headwaters in the northwestern Uinta Mountains, generally following the strike of regional Laramide and late Cenozoic structures. These structures likely also control the flow paths of groundwater that feeds Bear Lake, and groundwater-fed streams are the largest source of water when the lake is isolated from the Bear River. The present configuration of the Bear River with respect to Bear Lake Valley may not have been established until the late Pliocene. The absence of Uinta Range-derived quartzites in fluvial gravel on the crest of the Bear Lake Plateau east of Bear Lake suggests that the present headwaters were not part of the drainage basin in the late Tertiary. Newly mapped glacial deposits in the Bear River Range west of Bear Lake indicate several advances of valley glaciers that were probably coeval with glaciations in the Uinta Mountains. Much of the meltwater from these glaciers may have reached Bear Lake via groundwater pathways through infiltration in the karst terrain of the Bear River Range. At times during the Pleistocene, the Bear River flowed into Bear Lake and water level rose to the valley threshold at Nounan narrows. This threshold has been modified by aggradation, downcutting, and tectonics. Maximum lake

  13. Biology and chemistry of three Pennsylvania lakes: responses to acid precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Bradt, P.T.; Dudley, J.L.; Berg, M.B.; Barrasso, D.S.

    1986-09-01

    The biology and chemistry of three northeastern Pennsylvania lakes was studied from summer 1981 through summer 1983 to evaluate lakes with different sensitivities to acidification. At the acidified lake there were fewer phytoplankton and zooplankton species than at the moderately sensitive lakes. The most numerous plankton species in all three lakes are reportedly acid tolerant. Among the benthic macro-invertebrates (BMI) there were more acid tolerant Chironomidae at the acidified lake, but more acid intolerant Ephemeroptera and Mollusca and a higher wet weight at the least sensitive lake. There were no differences among the lakes' BMI mean total numbers or mean number of taxa. The fish community at the acidified lake was dominated by stunted Lepomis gibbosus, but L. machrochirous were most abundant in the other lakes. Principal component analysis suggested a shift in all three lakes over the sampling period toward combined lower pH, alkalinity, specific conductance, Ca and Mg and higher Al and Mn. Such chemical changes have been associated with acidification. The rate and extent of acidification appeared to be controlled by geological and hydrological characteristics of the drainage basins. 38 refs.

  14. A linked lake system beneath Thwaites Glacier, West Antarctica reveals an efficient mechanism for subglacial water flow.

    Science.gov (United States)

    Smith, B. E.; Gourmelen, N.; Huth, A.; Joughin, I. R.

    2016-12-01

    In this presentation we show the results of a multi-sensor survey of a system of subglacial lakes beneath Thwaites Glacier, West Antarctica. This is the first substantial active (meaning draining or filling on annual time scales) lake system detected under the fast-flowing glaciers of the Amundsen Coast. Altimetry data show that over the 2013 calendar year, four subglacial lakes drained, essentially simultaneously, with the bulk of the drainage taking place over the course the first three months of the year. The largest of the lakes appears to have drained around 3.7 km3 of water, with the others each draining less than 1 km3. The high-resolution radar surveys conducted in this area by NASA's IceBridge program allow detailed analysis of the subglacial hydrologic potential, which shows that the potential map in this area is characterized by small closed basins that should not, under the common assumption that water flow is directed down the gradient of the hydropotential, allow long-range water transport. The lakes' discharge demonstrates that, at least in some cases, water can flow out of apparently closed hydropotential basins. Combining a basal-flow routing map with a map of basal melt production suggests that the largest drainage event could recur as often as every 22 years, provided that overflow or leakage of mapped hydropotential basins allows melt water transport to refill the lake. An analysis of ice-surface speed records both around the lakes and at the Thwaites grounding line shows small changes in ice speed, but none clearly associated with the drainage event, suggesting that, at least in this area where subglacial melt is abundant, the addition of further water to the subglacial hydrologic system need not have any significant effect on ice flow. It is likely that the main impact of the lake system on the glacier is that as an efficient mechanism to remove meltwater from the system, it drains water that would otherwise flow through less efficient

  15. Flexural-response of the McMurdo Ice Shelf to surface lake filling and drainage

    Science.gov (United States)

    Banwell, A. F.; MacAyeal, D. R.; Willis, I.; Macdonald, G. J.; Goodsell, B.

    2017-12-01

    Antarctic ice-shelf instability and break-up, as exhibited by the Larsen B ice shelf in 2002, remains one of the most difficult glaciological processes to observe directly. It is, however, vital to do so because ice-shelf breakup has the potential to influence the buttressing controls on inland ice discharge, and thus to affect sea level. Several mechanisms enabling Larsen B style breakup have previously been proposed, including the ability of surface lakes to introduce ice-shelf fractures when they fill and drain. During the austral summer of 2016/2017, we monitored the filling and draining of four surface lakes on the McMurdo Ice Shelf, Antarctica, and the effect of these processes on ice-shelf flexure. Water-depth data from pressure sensors reveal that two lakes filled to >2 m in depth and subsequently drained over multiple week timescales, which had a simultaneous effect on vertical ice deflection in the area. Differential GPS data from 12 receivers over three months show that vertical deflection varies as a function of distance from the maximum load change (i.e. at the lake centre). Using remote sensing techniques applied to both Landsat 8 and Worldview imagery, we also quantify the meltwater volume in these two lakes through the melt season, which, together with the vertical deflection data, are used to constrain key flexural parameter values in numerical models of ice-shelf flexure.

  16. HYDROLOGIC MODELLING OF KATSINA-ALA RIVER BASIN: AN EMERGING SCENARIO FROM LAKE NYOS THREAT

    Directory of Open Access Journals (Sweden)

    J. O. Akinyede

    2012-07-01

    Full Text Available Understanding the hydrologic system surrounding crater lakes is of great importance for prevention of flooding damages, conservation of ecological environment, and assessment of socio-economic impact of dam failure on the civilians in the downstream regions. Lake Nyos is a crater lake formed by volcanic activities at the Oku volcanic field on the Cameroon Volcanic Line. It is a freshwater lake with a maximum depth of 200 meter. In 1986, a limnic eruption at the lake emitted 1.6 million tonnes of carbon dioxide from the bottom of saturated water into the air and suffocated up to 1,800 people and 3,500 livestock at nearby villages. The lake waters are held in place by a natural dam composed of loosely consolidated volcanic rock, which is now at the verge of collapse due to accelerated erosion. This study was carried out to determine the flood risks and vulnerability of population and infrastructure along Katsina-Ala drainage basins. The project integrated both satellite images and field datasets into a hydrologic model for Katsina-Ala River Basin and its vicinity including the Lake Nyos. ArcHydro was used to construct a hydrologic database as 'data models' and MIKE SHE was employed to conduct hydrologic simulations. Vulnerable infrastructures, population and socio-economic activities were identified to assist the Federal and State governments in disaster mitigation and management plans. The result of the project provides comprehensive knowledge of hydrologic system of Katsina-Ala drainage basin to mitigate potential future disasters from a potential dam failure and manage water resources against such disasters.

  17. Complex Drilling Logistics for Lake El’gygytgyn, NE Russia

    Directory of Open Access Journals (Sweden)

    Martin Melles,

    2009-03-01

    Full Text Available Lake El’gygytgyn was formed by astrophysical chance when a meteorite struck the Earth 100 km north of the Arctic Circle in Chukotka 3.6 Myrs ago (Layer, 2000 on the drainage divide between the Arctic Ocean and the Bering Sea. The crater measures ~18 km in diameter and lies nearly in the center of what was to become Beringia, the largestcontiguous landscape in the Arctic to have escaped continental scale glaciation. Within the crater rim today, Lake El’gygytgyn is 12 km in diameter and 170 m deep, enclosing 350–400 m of sediment deposited since the time of impact (Gebhardt et al., 2006. This setting makes the lake ideal for paleoclimate and impact research.

  18. Demonstration of isotope-mass balance approach for water budget analyses of El-burulus Lake, Nile Delta, Egypt

    International Nuclear Information System (INIS)

    Sadek, M.A.

    2006-01-01

    The major elements of El-Burulus lake water system are rainfall, agricultural drainage discharge, groundwater, human activities, evaporation and water interaction between the lake and the Mediterranean sea. The principal input sources are agricultural drainage (8 drains at the southern borders of the lake), sea water as well as some contribution of precipitation, groundwater and human activities. Water is lost from the lake through evaporation and surface outflow. The present study has been conducted using isotopic / mass balance approach to investigate the water balance of El-Burulus lake and to emphasize the relative contribution of different input / output components which affect the environmental and hydrological terms of the system. An isotopic evaporation pan experiment was performed to estimate the parameters of relevance to water balance (isotopic composition of free air moisture and evaporating flux) and to simulate the isotopic enrichment of evaporation under atmospheric and hydraulic control. The isotopic mass balance approach employed herein facilitated the estimation of groundwater inflow to the lake, evaporated fraction of total lake inflow (E/I) and its fraction to outflow (E/O), ratio of surface inflow to surface outflow (I/O) as well as residence time of lake water. The isotopic mass balance approach has been validated by comparing the values of estimated parameters with the previous hydrological investigations; a quite good match has been indicated, the relevance of this approach is related to its integrative scale and the more simply implementation

  19. Water-quality characteristics of Michigan's inland lakes, 2001-10

    Science.gov (United States)

    Fuller, L.M.; Taricska, C.K.

    2012-01-01

    statistically significant difference was found at the 95-percent confidence level among historical nutrients and trophic characteristics when comparing 445 lakes with historical data for 1974–84 with the 2001–10 dataset, though SDT did show statistically significant differences at the 95-percent confidence level. Depending on the primary indicator, 50–66 percent of lakes did not change trophic-status class, 13–23 percent moved towards the oligotrophic end of the TSI scale, and 20–25 percent moved a class towards the eutrophic end of the TSI scale. Increasing percentages of urban-dominant land cover in the drainage areas of lakes had a more positive correlation with chloride concentration than did increased percentages of other land-cover classes; there was also a slight correlation of urban-dominant land cover and calcium concentration. Removing data for lakes in southeastern Lower Michigan, known from previous reports to be higher in chloride, still resulted in a positive relation even though the coefficient of determination (R2 value) decreased from 0.55 to 0.39. Dominant land-cover drainage areas were not strongly related to nutrients with respect to a linear relation, nor were lake drainage-area sizes.

  20. Climate change and the global pattern of moraine-dammed glacial lake outburst floods

    Science.gov (United States)

    Harrison, Stephan; Kargel, Jeffrey S.; Huggel, Christian; Reynolds, John; Shugar, Dan H.; Betts, Richard A.; Emmer, Adam; Glasser, Neil; Haritashya, Umesh K.; Klimeš, Jan; Reinhardt, Liam; Schaub, Yvonne; Wiltshire, Andy; Regmi, Dhananjay; Vilímek, Vít

    2018-04-01

    Despite recent research identifying a clear anthropogenic impact on glacier recession, the effect of recent climate change on glacier-related hazards is at present unclear. Here we present the first global spatio-temporal assessment of glacial lake outburst floods (GLOFs) focusing explicitly on lake drainage following moraine dam failure. These floods occur as mountain glaciers recede and downwaste. GLOFs can have an enormous impact on downstream communities and infrastructure. Our assessment of GLOFs associated with the rapid drainage of moraine-dammed lakes provides insights into the historical trends of GLOFs and their distributions under current and future global climate change. We observe a clear global increase in GLOF frequency and their regularity around 1930, which likely represents a lagged response to post-Little Ice Age warming. Notably, we also show that GLOF frequency and regularity - rather unexpectedly - have declined in recent decades even during a time of rapid glacier recession. Although previous studies have suggested that GLOFs will increase in response to climate warming and glacier recession, our global results demonstrate that this has not yet clearly happened. From an assessment of the timing of climate forcing, lag times in glacier recession, lake formation and moraine-dam failure, we predict increased GLOF frequencies during the next decades and into the 22nd century.

  1. Seventh symposium on coal mine drainage research. NCA/BCR coal conference and Expo IV

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    The Seventh Symposium on Coal Mine Drainage Research, sponsored by the National Coal Association and Bituminous Coal Research, Inc., was held at the Kentucky Fair and Exposition Center, Louisville, Kentucky, October 18-20, 1977. Seventeen papers from the proceedings have been entered individually into EDB and ERA. Topics covered include chemical reactions of pyrite oxidation and acid formation in spoil banks, abandoned mines, etc., formation of small acid lakes from the drainage and their neutralization by natural and other neutralization measures, trace elements in acid mine drainage, ground water contamination, limnology, effects of surface mined ground reclamation and neutralization, water purification and treatment, mining and coal preparation plant waste disposal, ash and fly ash disposal (to minimize leaching from the wastes), runoff from large coal storage stockpiles during storms (prevention of environmental effects by collection and neutralization by passing through an ash pond). (LTN)

  2. Using a mass balance to understand the geology and geochemistry of a reservoir receiving and discharging acid mine drainage

    International Nuclear Information System (INIS)

    Turney, D.C.; Edwards, K.

    1996-01-01

    Howard-Williams Lake is a 14.5 acre reservoir located in an abandoned coal mine in Perry County, Ohio. With a pH of 3.0 and acidity values of 300--400 mg/L, the reservoir has no plants or fish currently surviving in the lake. Reclamation of spoil piles adjacent to the lake to the north in the late 1980s was not successful in reducing the acidity of the lake. Currently, papermill sludge is being used on the reclaimed area to the north to promote vegetation, but the reservoir has shown no signs of improving. The goal of this project is to transform the lake into a fishable and swimmable one. The reservoir is receiving about 175 gallons per minute of acid mine drainage, not including seepage into the lake, from eight different sources. Three of the sources account for about 165 gallons per minute of the surface water that enters the lake. These inflows have relatively low acidity readings, which range from 66 mg/L to 568 mg/L. The other five sources of acid mine drainage have much lower flowrates, but have acidity values as high as 3,000 mg/L. Samples of all of the surface inflows and the outflow of the lake were taken and sent to a laboratory and tested for the following parameters: total acidity as CaCO 3 , total alkalinity as CaCO 2 , specific conductivity, total suspended solids, sulfate, chloride calcium, magnesium, sodium, potassium, total iron, total manganese, aluminum, and hardness. During sampling of the surface inflows, volumetric flowrates were measured for each inflow. Once the flowrates and the concentrations of the various parameters were known, a mass balance could be constructed which would show how much of each parameter was entering the lake each day. These data were then used to gain an understanding of the geochemistry and geology of the site

  3. Spatial characterization of acid rain stress in Canadian Shield Lakes

    Science.gov (United States)

    Tanis, Fred J.

    1987-01-01

    The acidification of lake waters from airborne pollution is of continental proportions both in North America and Europe. A major concern of the acid rain problem is the cumulative ecosystem damage to lakes and forest. The number of lakes affected in northeastern U.S. and on the Canadian Shield is though to be enormous. How seasonal changes in lake transparency are related to annual acidic load was examined. The relationship between variations in lake acidification and ecophysical units was also examined. The utility of Thematic Mapper based observations to measure seasonal changes in the optical transparency in acid lakes was investigated. The potential for this optical response is related to a number of local ecophysical factors with bedrock geology being, perhaps, the most important. Other factors include sulfate deposition, vegetative cover, and terrain drainage/relief. The area of southern Ontario contains a wide variety of geologies from the most acid rain sensitive granite quartzite types to the least sensitive limestone dolomite sediments. Annual sulfate deposition ranges from 1.0 to 4.0 grams/sq m.

  4. The radiological hazards of some radionuclides in Mariout and Brullus Lakes, Egypt

    International Nuclear Information System (INIS)

    Dar, M.A.; El Saharty, A.A.

    2012-01-01

    Mariout and Brullus were considered two of the highly fish productive lakes in Egypt as well as they widely used to drain huge quantities of industrial wastewater, sewage and agriculture drainage. Thousands of peoples inhabited the areas around the lakes and depend on them completely in their lives. The activities of 238 U, 232 Th and 40 K were measured in the upper most part of the surface sediments of the two lakes using gamma ray spectrophotometery. Brullus Lake recorded significantly higher 238 U and 232 Th and lower 40 K (17.22±2.49 Bq/kg, 10.0 ±56 Bq/kg and 299.7±17.78 Bq/kg) than Mariout Lake (12.65±1.53 Bq/kg, 7.24±0.76 Bq/kg and 518.75±46.24 Bq/kg respectively). Inversely, the mean average of absorbed dose rate (D), annual effective dose rate (mSvy -1 ), radium equivalent (Ra eq ), external hazard index (H ex ) and the representative level index (Iγr) were; 32.01 nGy/h, 0.04 mSv/y, 62.95 Bq/kg, 0.17 and 0.50 at Mariout Lake higher than those in Brullus lake (26.42 nGy/h, 0.03 mSv/y, 54.25 Bq/kg, 0.15 and 0.41) respectively. The recorded and calculated values were lower than the acceptable limits published in the different localities around the world. The activity distributions of the radiological hazards show the highest intensities in the western part of Mariout Lake and decreasing gradually eastward and north eastward affecting by the drainage agriculture water from Kabary Drain, Umum Drain, S.W. Basin and Nubaria Canal. At Brullus Lake, the radiological hazard intensities were concentrated in the west and southwest influenced by Zaglul Drain, Rosetta Drain, Brembal canal, Drain 11, Drain 9, Drain 8 and partially by Drain 1 while the lowest intensities were in the north and northeast affecting by the interaction with the Mediterranean Sea. K-40 recorded positive correlations and significant linear regression relationships with radiological hazard parameters at Mariout Like meaning that 40 K is the main gamma emitter in the lake, while the

  5. Transfer of Chernobyl-derived 137Cs into fishes in some Finnish lakes

    International Nuclear Information System (INIS)

    Saxen, R.; Koskelainen, U.; Alatalo, M.

    2000-09-01

    This report summarises STUK's work for the hydrological modelling (WG 4) in RODOS C, a project co-ordinated by the EU, in 1996-1999. The role of STUK in the project was to provide a data set on the radio-caesium contents in different types of fish and lakes in northern European environmental conditions for the development of a dynamic regional model describing radio-caesium transfer into fish. The co-operating institute, Technical Research Centre of Finland (VTT), was responsible for the modelling work in this project. Besides the analysed data on 137 Cs in the various fish species in the lakes, background information was produced on lakes and their drainage areas that might affect radio-caesium transfer into fish, which was needed for the development of fish, lake and drainage basin models. The role of STUK included also providing another, independent data set for the validation of the model. The proposals and needs of the co-operating institute, VTT, were taken into account. One of the factors strongly affecting the transfer of 137 Cs into fish is the nutrition level of the lake. The average transfer of 137 Cs in predators at the time of maximum activity concentrations in oligotrophic lakes was found to be up to 0.10 m 2 /kg, implying that approximately 10% of the amount of 137 Cs deposited on one square metre is transferred into 1 kg of fish. The corresponding transfer in eutrophic lakes was clearly lower,.i.e. 3- 4%, at the time of maximum concentrations, which usually occurred 1- 3 years after the deposition, depending on the fish species. These time-dependent transfer coefficients can be regarded as a kind of a lake-specific model. If deposition to the lake is known, the activity concentrations in fish can be estimated within specific uncertainty limits, by multiplying the deposition value by the transfer coefficient at a certain time point. Temporal changes in annual averages of transfer coefficients with variation for a certain set of lakes and for three

  6. Investigation of environmental change on the Tega Lake based on lake sediment analysis. Pt. 2. Dating of sediment by the lead-210/cesium-137 method and environmental change detected by the diatom assemblage analysis

    International Nuclear Information System (INIS)

    Hamada, Takaomi

    1998-01-01

    Sediment collected in the Tega Lake was dated by lead-210/cesium-137 method and environmental change in the Tega Lake was investigated by analysis of diatom remain assemblages in the sediment. Dating of the lead-210/cesium-137 method proved that the surface 30 cm-thickness of sediment in the Tega Lake was deposited during the recent 50 years. Diatom remain assemblage change in the Hon-Tega Lake sediment started in the early half of 1960's and the changes is characterized decrease of Fragilaria construens, that does not prefer to inhabit eutrophic water, and increase of Cyclotella meneghiniana that prefers to inhabit eutrophic water. This diatom assemblage change indicates that the Tega Lake was eutrophicated, and probably suggests water pollution in the Tega Lake. It is detected that influence of residential development around the Tega Lake and reclaiming by drainage on the Tega Lake. (author)

  7. Spatial distribution and temporal development of high-mountain lakes in western Austria

    Science.gov (United States)

    Merkl, Sarah; Emmer, Adam; Mergili, Martin

    2015-04-01

    Glacierized high-mountain environments are characterized by active morphodynamics, favouring the rapid appearance and disappearance of lakes. On the one hand, such lakes indicate high-mountain environmental changes such as the retreat of glaciers. On the other hand, they are sometimes susceptible to sudden drainage, leading to glacial lake outburst floods (GLOFs) putting the downstream population at risk. Whilst high-mountain lakes have been intensively studied in the Himalayas, the Pamir, the Andes or the Western Alps, this is not the case for the Eastern Alps. A particular research gap, which is attacked with the present work, concerns the western part of Austria. We consider a study area of approx. 6,140 km², covering the central Alps over most of the province of Tyrol and part of the province of Salzburg. All lakes ≥250 m² located higher than 2000 m asl are mapped from high-resolution Google Earth imagery and orthophotos. The lakes are organized into seven classes: (i) ice-dammed; near-glacial (ii) moraine-dammed and (iii) bedrock-dammed; (iv) moraine-dammed and (v) bedrock-dammed distant to the recent glaciers; (vi) landslide-dammed; (vii) anthropogenic. The temporal development of selected lakes is investigated in detail, using aerial photographs dating back to the 1950s. 1045 lakes are identified in the study area. Only eight lakes are ice-dammed (i). One third of all lakes is located in the immediate vicinity of recent glacier tongues, half of them impounded by moraine (ii), half of them by bedrock (iii). Two thirds of all lakes are impounded by features (either moraines or bedrock) shaped by LIA or Pleistocenic glaciers at some distance to the present glacier tongues (iv and v). Only one landslide-dammed lake (vi) is identified in the study area, whilst 21 lakes are of anthropogenic origin (vii). 72% of all lakes are found at 2250-2750 m asl whilst less than 2% are found above 3000 m asl. The ratio of rock-dammed lakes increases with increasing

  8. Ensuring safe use of water in a river basin with uranium drainage

    International Nuclear Information System (INIS)

    Carvalho, F.; Oliveira, J.; Malta, M.

    2014-01-01

    A regular radioactivity monitoring programme ensures radioactivity surveillance in a river system with multiple and intensive uses of water. In the catchment of River Mondego, centre of Portugal, there is a uranium mining and milling legacy which encompasses about 12 old uranium mine sites and 3 uranium milling sites. This river basin is an important agriculture and cattle growing region with forest areas for paper pulp production. In the catchment of this river there are four dams for electricity production and two main artificial lakes which are water reservoirs to supply drinking water to more than 3 million people, and irrigation water for agriculture including maize and rice production. In the river basin, environmental remediation works were recently implemented especially at the milling tailings and at the major mine sites, which reduced radioactive drainage into the Mondego tributaries and thus into the Mondego river. Mine drainage and seepage from tailings are recuperated and treated in mine water treatment stations. Although, for example, in drainage from milling tailings at Urgeiriça, water may contain high concentrations of dissolved uranium ("2"3"8U), radium ("2"2"6Ra) and polonium ("2"1"0Po) at 35,700±1100, 1084±30, and 700±40 mBq/L, respectively, in the stream receiving discharges of treated water today radionuclide concentrations are orders of magnitude lower. The tributary streams that in the past received untreated mine discharges are today recovering and concentrations decreased to near natural levels. In the artificial lake of Aguieira dam, built on the Mondego River downstream all uranium sites, and where the main capture of water for human consumption is located, radionuclide concentrations were of 9.2±0.3 mBq/L, 17.7±1.9 mBq/L, and 5.3±0.2 mBq/L for uranium ("2"3"8U), radium ("2"2"6Ra) and polonium ("2"1"0Po), respectively. This water has been over the last years consistently in compliance with the EU drinking water quality standards

  9. Characterizing post-drainage succession in Thermokarst Lake Basins on the Seward Peninsula, Alaska with TerraSAR-X Backscatter and Landsat-based NDVI data

    Science.gov (United States)

    Regmi, Prajna; Grosse, Guido; Jones, Miriam C.; Jones, Benjamin M.; Walter Anthony, Katey

    2012-01-01

    Drained thermokarst lake basins accumulate significant amounts of soil organic carbon in the form of peat, which is of interest to understanding carbon cycling and climate change feedbacks associated with thermokarst in the Arctic. Remote sensing is a tool useful for understanding temporal and spatial dynamics of drained basins. In this study, we tested the application of high-resolution X-band Synthetic Aperture Radar (SAR) data of the German TerraSAR-X satellite from the 2009 growing season (July–September) for characterizing drained thermokarst lake basins of various age in the ice-rich permafrost region of the northern Seward Peninsula, Alaska. To enhance interpretation of patterns identified in X-band SAR for these basins, we also analyzed the Normalized Difference Vegetation Index (NDVI) calculated from a Landsat-5 Thematic Mapper image acquired on July 2009 and compared both X-band SAR and NDVI data with observations of basin age. We found significant logarithmic relationships between (a) TerraSAR-X backscatter and basin age from 0 to 10,000 years, (b) Landat-5 TM NDVI and basin age from 0 to 10,000 years, and (c) TerraSAR-X backscatter and basin age from 50 to 10,000 years. NDVI was a better indicator of basin age over a period of 0–10,000 years. However, TerraSAR-X data performed much better for discriminating radiocarbon-dated basins (50–10,000 years old). No clear relationships were found for either backscatter or NDVI and basin age from 0 to 50 years. We attribute the decreasing trend of backscatter and NDVI with increasing basin age to post-drainage changes in the basin surface. Such changes include succession in vegetation, soils, hydrology, and renewed permafrost aggradation, ground ice accumulation and localized frost heave. Results of this study show the potential application of X-band SAR data in combination with NDVI data to map long-term succession dynamics of drained thermokarst lake basins.

  10. Characterizing Post-Drainage Succession in Thermokarst Lake Basins on the Seward Peninsula, Alaska with TerraSAR-X Backscatter and Landsat-based NDVI Data

    Directory of Open Access Journals (Sweden)

    Prajna Regmi

    2012-11-01

    Full Text Available Drained thermokarst lake basins accumulate significant amounts of soil organic carbon in the form of peat, which is of interest to understanding carbon cycling and climate change feedbacks associated with thermokarst in the Arctic. Remote sensing is a tool useful for understanding temporal and spatial dynamics of drained basins. In this study, we tested the application of high-resolution X-band Synthetic Aperture Radar (SAR data of the German TerraSAR-X satellite from the 2009 growing season (July–September for characterizing drained thermokarst lake basins of various age in the ice-rich permafrost region of the northern Seward Peninsula, Alaska. To enhance interpretation of patterns identified in X-band SAR for these basins, we also analyzed the Normalized Difference Vegetation Index (NDVI calculated from a Landsat-5 Thematic Mapper image acquired on July 2009 and compared both X-band SAR and NDVI data with observations of basin age. We found significant logarithmic relationships between (a TerraSAR-X backscatter and basin age from 0 to 10,000 years, (b Landat-5 TM NDVI and basin age from 0 to 10,000 years, and (c TerraSAR-X backscatter and basin age from 50 to 10,000 years. NDVI was a better indicator of basin age over a period of 0–10,000 years. However, TerraSAR-X data performed much better for discriminating radiocarbon-dated basins (50–10,000 years old. No clear relationships were found for either backscatter or NDVI and basin age from 0 to 50 years. We attribute the decreasing trend of backscatter and NDVI with increasing basin age to post-drainage changes in the basin surface. Such changes include succession in vegetation, soils, hydrology, and renewed permafrost aggradation, ground ice accumulation and localized frost heave. Results of this study show the potential application of X-band SAR data in combination with NDVI data to map long-term succession dynamics of drained thermokarst lake basins.

  11. Climate change and the global pattern of moraine-dammed glacial lake outburst floods

    Directory of Open Access Journals (Sweden)

    S. Harrison

    2018-04-01

    Full Text Available Despite recent research identifying a clear anthropogenic impact on glacier recession, the effect of recent climate change on glacier-related hazards is at present unclear. Here we present the first global spatio-temporal assessment of glacial lake outburst floods (GLOFs focusing explicitly on lake drainage following moraine dam failure. These floods occur as mountain glaciers recede and downwaste. GLOFs can have an enormous impact on downstream communities and infrastructure. Our assessment of GLOFs associated with the rapid drainage of moraine-dammed lakes provides insights into the historical trends of GLOFs and their distributions under current and future global climate change. We observe a clear global increase in GLOF frequency and their regularity around 1930, which likely represents a lagged response to post-Little Ice Age warming. Notably, we also show that GLOF frequency and regularity – rather unexpectedly – have declined in recent decades even during a time of rapid glacier recession. Although previous studies have suggested that GLOFs will increase in response to climate warming and glacier recession, our global results demonstrate that this has not yet clearly happened. From an assessment of the timing of climate forcing, lag times in glacier recession, lake formation and moraine-dam failure, we predict increased GLOF frequencies during the next decades and into the 22nd century.

  12. Benthic foraminiferal assemblages as bio-indicators of metals contamination in sediments, Qarun Lake as a case study, Egypt

    Science.gov (United States)

    Abd El Naby, Ahmed; Al Menoufy, Safia; Gad, Ahmed

    2018-03-01

    Qarun Lake, in the Fayoum Depression of the Western Desert of Egypt, lies within the deepest area in the River Nile flood plain. The drainage water in the Qarun Lake is derived from the discharge of the natural and artificial drainage systems in the Fayoum. Mixed domestic and agricultural pollutants, including heavy metals, nitrates, phosphates, sulfates and pesticides, are discharged into Qarun Lake. Forty-six samples, collected from the undisturbed layer of sediments were used for benthic foraminiferal analysis. Concentrations of some selected trace metal elements (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V, and Zn) were also determined. Statistical analysis of the abiotic variables (Texture distribution of sediments, Physico-chemical parameters, and metals concentrations) and of the biotic variables (distribution of benthic foraminiferal species) were also performed. The Q-mode cluster analysis of benthic foraminiferal distribution has provided evidence that the Qarun Lake can be subdivided into two cluster groups (A and B), reflecting environmental changes in the lake ecosystem. Cluster B can also be subdivided into two sub-clusters (B1 and B2). The presence of only pollution tolerant taxa with higher faunal density and lower diversity and the absence of the other foraminiferal assemblages in cluster A were attributed to the high concentration of trace metal elements and the strong environmental stress at the eastern and central parts of the Qarun Lake.

  13. Transfer of Chernobyl-derived {sup 137}Cs into fishes in some Finnish lakes

    Energy Technology Data Exchange (ETDEWEB)

    Saxen, R.; Koskelainen, U.; Alatalo, M

    2000-09-01

    This report summarises STUK's work for the hydrological modelling (WG 4) in RODOS C, a project co-ordinated by the EU, in 1996-1999. The role of STUK in the project was to provide a data set on the radio-caesium contents in different types of fish and lakes in northern European environmental conditions for the development of a dynamic regional model describing radio-caesium transfer into fish. The co-operating institute, Technical Research Centre of Finland (VTT), was responsible for the modelling work in this project. Besides the analysed data on {sup 137}Cs in the various fish species in the lakes, background information was produced on lakes and their drainage areas that might affect radio-caesium transfer into fish, which was needed for the development of fish, lake and drainage basin models. The role of STUK included also providing another, independent data set for the validation of the model. The proposals and needs of the co-operating institute, VTT, were taken into account. One of the factors strongly affecting the transfer of {sup 137}Cs into fish is the nutrition level of the lake. The average transfer of {sup 137}Cs in predators at the time of maximum activity concentrations in oligotrophic lakes was found to be up to 0.10 m{sup 2}/kg, implying that approximately 10% of the amount of {sup 137}Cs deposited on one square metre is transferred into 1 kg of fish. The corresponding transfer in eutrophic lakes was clearly lower,.i.e. 3- 4%, at the time of maximum concentrations, which usually occurred 1- 3 years after the deposition, depending on the fish species. These time-dependent transfer coefficients can be regarded as a kind of a lake-specific model. If deposition to the lake is known, the activity concentrations in fish can be estimated within specific uncertainty limits, by multiplying the deposition value by the transfer coefficient at a certain time point. Temporal changes in annual averages of transfer coefficients with variation for a certain

  14. Fish otoliths analysis by PIXE: application to stock discrimination

    International Nuclear Information System (INIS)

    Arai, Nobuaki; Takai, Noriyuki; Sakamoto, Wataru; Yoshida, Koji; Maeda, Kuniko.

    1996-01-01

    Fish otoliths are continuously deposited from fish birth to its death along with encoding environmental information. In order to decode the information, PIXE was adopted as trace elemental analysis of the otoliths. Strontium to calcium concentration ratios of red sea bream otoliths varied among rearing stations. The Sr/Ca ratios of Lake Biwa catfishes also varied between male and female and among fishing grounds. The PIXE analysis was applied to the fish stock discrimination. (author)

  15. Methyl mercury concentrations in macroinvertebrates and fish from burned and undisturbed lakes on the Boreal Plain

    Energy Technology Data Exchange (ETDEWEB)

    Allen, E.W. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences; Prepas, E.E. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences; Lakehead Univ., Thunder Bay, ON (Canada). Faculty of Forest and the Forest Environment; Gabos, S.; Zhang, W. [Alberta Health and Wellness, Edmonton, AB (Canada); Strachan, W.M.J. [Environment Canada, Burlington, ON (Canada). National Water Research Inst.

    2005-09-01

    Methylmercury (MeHg) concentrations in macroinvertebrates and fish from 5 lakes in burned catchments in Alberta's Swan Hills region were compared with those from 5 reference lakes on the western Canadian Boreal Plain. The objective was to determine the effect of forest fire on the bioaccumulation of MeHg, a toxic pollutant. It was noted that lakes near the Alberta Special Waste Treatment Centre (ASWTC) have fish consumption advisories due to high mercury concentrations. In a separate comparison, MeHg concentrations in biota from a single lake were compared before and after a forest fire interrupted a prescribed timber harvest experiment. The affect of lake water chemistry, watershed characteristics, and trophic ecology on the bioaccumulation and biomagnification of MeHg in littoral food webs was also examined. The study area covered 2 ecoregions, the Boreal Foothills and the Boreal Mixedwood. Two years after the fire, MeHg concentrations in 5 of 6 aquatic taxa did not differ between burned and reference drainage basins in the Swan Hills. These results were in agreement with previous studies. Biomagnification of MeHg was negatively correlated with lake water chlorophyll 'a' concentration. Ecoregional variation in water chemistry seemed to influence MeHg concentrations in aquatic biota, which eluded comparisons of MeHg bioaccumulation between burned and reference drainage basins. MeHg concentrations in biota were negatively correlated with lake water pH, as well as with total phosphorous and dominant cation concentrations, all of which were higher in Mixedwood than in Foothills lakes. It was concluded that in the short-term, fire may lower MeHg concentrations in aquatic biota in a nutrient-rich setting by inducing an increase in lake productivity that dilutes MeHg at the base of the food web. 42 refs., 5 tabs., 7 figs.

  16. Comparative analysis of discharges into Lake Michigan, Phase I - Southern Lake Michigan.

    Energy Technology Data Exchange (ETDEWEB)

    Veil, J. A.; Elcock, D.; Gasper, J. R.; Environmental Science Division

    2008-06-30

    BP Products North America Inc. (BP) owns and operates a petroleum refinery located on approximately 1,700 acres in Whiting, East Chicago, and Hammond, Indiana, near the southern tip of Lake Michigan. BP provided funding to Purdue University-Calumet Water Institute (Purdue) and Argonne National Laboratory (Argonne) to conduct studies related to wastewater treatment and discharges. Purdue and Argonne are working jointly to identify and characterize technologies that BP could use to meet the previous discharge permit limits for total suspended solids (TSS) and ammonia after refinery modernization. In addition to the technology characterization work, Argonne conducted a separate project task, which is the subject of this report. In Phase I of a two-part study, Argonne estimated the current levels of discharge to southern Lake Michigan from significant point and nonpoint sources in Illinois, Indiana, and portions of Michigan. The study does not consider all of the chemicals that are discharged. Rather, it is narrowly focused on a selected group of pollutants, referred to as the 'target pollutants'. These include: TSS, ammonia, total and hexavalent chromium, mercury, vanadium, and selenium. In Phase II of the study, Argonne will expand the analysis to cover the entire Lake Michigan drainage basin.

  17. Preservation of labile organic matter in soils of drained thaw lakes in Northern Alaska

    Science.gov (United States)

    Mueller, Carsten W.; Rethemeyer, Janet; Kao-Kniffin, Jenny; Löppmann, Sebastian; Hinkel, Kenneth; Bockheim, James

    2014-05-01

    A large number of studies predict changing organic matter (OM) dynamics in arctic soils due to global warming. In contrast to rather slowly altering bulk soil properties, single soil organic matter (SOM) fractions can provide a more detailed picture of the dynamics of differently preserved SOM pools in climate sensitive arctic regions. By the study of the chemical composition of such distinctive SOM fractions using nuclear magnetic resonance spectroscopy (NMR) together with radiocarbon analyses it is possible to evaluate the stability of the major OM pools. Approximately 50-75% of Alaska's Arctic Coastal Plain is covered with thaw lakes and drained thaw lakes that follow a 5,000 yr cycle of development (between creation and final drainage), thus forming a natural soil chronosequence. The drained thaw lakes offer the possibility to study SOM dynamics affected by permafrost processes over millennial timescales. In April 2010 we sampled 16 soil cores (including the active and permanent layer) reaching from young drained lakes (0-50 years since drainage) to ancient drained lakes (3000-5500 years since drainage). Air dried soil samples from soil horizons of the active and permanent layer were subjected to density fractionation in order to differentiate particulate OM and mineral associated OM. The chemical composition of the SOM fractions was analyzed by 13C CPMAS NMR spectroscopy. For a soil core of a young and an ancient drained thaw lake basin we also analyzed the 14C content. For the studied soils we can show that up to over 25 kg OC per square meter are stored mostly as labile, easily degradable organic matter rich in carbohydrates. In contrast only 10 kg OC per square meter were sequestered as presumably more stable mineral associated OC dominated by aliphatic compounds. Comparable to soils of temperate regions, we found small POM (dating we could show the stabilization of younger more labile OM at greater depth in buried O horizons. Additionally the study of the

  18. A combined CaO/electrochemical treatment of the acid mine drainage from the "Robule" Lake.

    Science.gov (United States)

    Orescanin, Visnja; Kollar, Robert

    2012-01-01

    The purpose of this work was development and application of the purification system suitable for the treatment of the acid mine drainage (AMD) accumulated in the "Robule" Lake, which represents the part of the Bor copper mining and smelting complex, Serbia. The study was undertaken in order to minimize adverse effect on the environment caused by the discharge of untreated AMD, which was characterized with low pH value (2.63) and high concentration of heavy metals (up to 610 mg/L) and sulfates (up to 12,000 mg/L). The treatment of the effluent included pretreatment/pH adjustment with CaO followed by electrocoagulation using iron and aluminum electrode sets. Following the final treatment, the decrease in the concentration of heavy metals ranged from 40 up to 61000 times depending on the metal and its initial concentration. The parameters, color and turbidity were removed completely in the pretreatment step, while the removal efficiencies for other considered parameters were as follows: EC = 55.48%, SO(4) (2-) = 70.83%, Hg = 98.36%, Pb = 97.50%, V = 98.43%, Cr = 99.86%, Mn = 97.96%, Fe = 100.00%, Co = 99.96%, Ni = 99.78%, Cu = 99.99% and Zn = 99.94%. Because the concentrations of heavy metals in the electrochemically treated AMD (ranging from 0.001 to 0.336 mg/L) are very low, the negative impact of this effluent on the aquatic life and humans is not expected. The sludge generated during the treatment of AMD is suitable for reuse for at least two purposes (pretreatment of AMD and covering of the flotation waste heap). From the presented results, it could be concluded that electrochemical treatment is a suitable approach for the treatment of AMD.

  19. PILOT STUDIES WITH A PHOTOGRAMMETRIC GLACIER LAKE OUTBURST FLOOD EARLY WARNING SYSTEM

    Directory of Open Access Journals (Sweden)

    H. G. Maas

    2012-07-01

    Full Text Available Glacier Lake Outburst Floods (GLOFs depict an environmental risk with an increasing damage potential in many regions of the world. GLOFs are often caused by glacier margin lakes, which suddenly find a drainage path underneath the bottom of a glacier, which is destabilized and retreating as a consequence of local or global climate changes. In a typical GLOF event, a glacier margin lake may drain completely in 24 hours, causing a large flood wave in the area downstream the glacier. The paper documents some recent GLOF events in the Northern Patagonian Icefield (Chile and presents a terrestrial photogrammetric glacier margin lake monitoring system. The system is based on a camera taking images at regular time intervals. In these images, variations of the water level can be detected by tracking the water-land interface at pre-defined image spots. Due to the drainage mechanism, which is characterized by progressive erosion and melting at the bottom of the glacier, GLOFs are indicated by a progressive water level drop in the lake. Water level changes may be detected with subpixel accuracy by image sequence processing methods. If a 3D model of the lake bottom topography (or at least one height profile through the lake exists, water level changes in monoscopic image sequences may be transformed into volume loss. The basic idea herein is the intersection of a terrain profile with a water level detected in the image and projected into object space. The camera orientation is determined through a GPS-supported photogrammetric network. Camera orientation changes, which may for instance be induced by wind, can be compensated by tracking some fiducial marks in the image. The system has been used in a pilot study at two glacier margin lakes in the Northern Patagonian Icefield. These lakes have a depth of about 80 - 100 meters. The larger one has a length of 5 km and a maximum volume of about 200,000,000 cubic meters. During the pilot study, several GLOF events

  20. New age constraints for the Saalian glaciation in northern central Europe: Implications for the extent of ice sheets and related proglacial lake systems

    Science.gov (United States)

    Lang, Jörg; Lauer, Tobias; Winsemann, Jutta

    2018-01-01

    A comprehensive palaeogeographic reconstruction of ice sheets and related proglacial lake systems for the older Saalian glaciation in northern central Europe is presented, which is based on the integration of palaeo-ice flow data, till provenance, facies analysis, geomorphology and new luminescence ages of ice-marginal deposits. Three major ice advances with different ice-advance directions and source areas are indicated by palaeo-ice flow directions and till provenance. The first ice advance was characterised by a southwards directed ice flow and a dominance of clasts derived from southern Sweden. The second ice advance was initially characterised by an ice flow towards the southwest. Clasts are mainly derived from southern and central Sweden. The latest stage in the study area (third ice advance) was characterised by ice streaming (Hondsrug ice stream) in the west and a re-advance in the east. Clasts of this stage are mainly derived from eastern Fennoscandia. Numerical ages for the first ice advance are sparse, but may indicate a correlation with MIS 8 or early MIS 6. New pIRIR290 luminescence ages of ice-marginal deposits attributed to the second ice advance range from 175 ± 10 to 156 ± 24 ka and correlate with MIS 6. The ice sheets repeatedly blocked the main river-drainage pathways and led to the formation of extensive ice-dammed lakes. The formation of proglacial lakes was mainly controlled by ice-damming of river valleys and major bedrock spillways; therefore the lake levels and extends were very similar throughout the repeated ice advances. During deglaciation the lakes commonly increased in size and eventually drained successively towards the west and northwest into the Lower Rhine Embayment and the North Sea. Catastrophic lake-drainage events occurred when large overspill channels were suddenly opened. Ice-streaming at the end of the older Saalian glaciation was probably triggered by major lake-drainage events.

  1. Estimation of sediment inflows to Lake Tuscaloosa, Alabama, 2009-11

    Science.gov (United States)

    Lee, K.G.

    2013-01-01

    The U.S. Geological Survey, in cooperation with the City of Tuscaloosa, evaluated the concentrations, loads, and yields of suspended sediment in the tributaries to Lake Tuscaloosa in west-central Alabama, from October 1, 2008, to January 31, 2012. The collection and analysis of these data will facilitate the comparison with historical data, serve as a baseline for future sediment-collection efforts, and help to identify areas of concern. Lake Tuscaloosa, at the reservoir dam, receives runoff from a drainage area of 423 square miles (mi2). Basinwide in 2006, forested land was the primary land cover (68 percent). Comparison of historical imagery with the National Land Cover Database (2001 and 2006) indicated that the greatest temporal land-use change was timber harvest. The land cover in 2006 was indicative of this change, with shrub/scrub land (12 percent) being the secondary land use in the basin. Agricultural land use (10 percent) was represented predominantly by hay and pasture or grasslands. Urban land use was minimal, accounting for 4 percent of the entire basin. The remaining 6 percent of the basin has a land use of open water or wetlands. Storm and monthly suspended-sediment samples were collected from seven tributaries to Lake Tuscaloosa: North River, Turkey Creek, Binion Creek, Pole Bridge Creek, Tierce Creek, Carroll Creek, and Brush Creek. Suspended-sediment concentrations and streamflow measurements were statistically analyzed to estimate annual suspended-sediment loads and yields from each of these contributing watersheds. Estimated annual suspended-sediment yields in 2009 were 360, 540, and 840 tons per square mile (tons/mi2) at the North River, Turkey Creek, and Carroll Creek streamflow-gaging stations, respectively. Estimated annual suspended-sediment yields in 2010 were 120 and 86 tons/mi2 at the Binion Creek and Pole Bridge Creek streamflow-gaging stations, respectively. Estimated annual suspended-sediment yields in 2011 were 190 and 300 tons/mi2

  2. Comparison between autologous blood transfusion drainage and closed-suction drainage/no drainage in total knee arthroplasty: a meta-analysis.

    Science.gov (United States)

    Hong, Kun-Hao; Pan, Jian-Ke; Yang, Wei-Yi; Luo, Ming-Hui; Xu, Shu-Chai; Liu, Jun

    2016-08-01

    Autologous blood transfusion (ABT) drainage system is a new unwashed salvaged blood retransfusion system for total knee replacement (TKA). However, whether to use ABT drainage, closed-suction (CS) drainage or no drainage in TKA surgery remains controversial. This is the first meta-analysis to assess the clinical efficiency, safety and potential advantages regarding the use of ABT drains compared with closed-suction/no drainage. PubMed, Embase, and the Cochrane Library were comprehensively searched in March 2015. Fifteen randomized controlled trials (RCTs) were identified and pooled for statistical analysis. The primary outcome evaluated was homologous blood transfusion rate. The secondary outcomes were post-operative haemoglobin on days 3-5, length of hospital stay and wound infections after TKA surgery. The pooled data included 1,721 patients and showed that patients in the ABT drainage group might benefit from lower blood transfusion rates (16.59 % and 37.47 %, OR: 0.28 [0.14, 0.55]; 13.05 % and 16.91 %, OR: 0.73 [0.47,1.13], respectively). Autologous blood transfusion drainage and closed-suction drainage/no drainage have similar clinical efficacy and safety with regard to post-operative haemoglobin on days 3-5, length of hospital stay and wound infections. Autologous blood transfusion drainage offers a safe and efficient alternative to CS/no drainage with a lower blood transfusion rate. Future large-volume high-quality RCTs with extensive follow-up will affirm and update this system review.

  3. Summertime nocturnal drainage flow in the San Mateo and Ambrosia lake air sheds of the grants basin

    International Nuclear Information System (INIS)

    Gedayloo, T.; Barr, S.; Clements, W.E.; Wilson, S.K.

    1979-01-01

    An initial study of some fundamental meteorological properties of two major air sheds in the Grants Basin of northwestern New Mexico was conducted from May 18 to September 19, 1978. Three mechanical weather stations were used in conjunction with a few vertical wind soundings to develop a data set for the summer regime. Data collected between May 18 and July 30 is analyzed to investigate nocturnal drainage flows, daytime flows, and channeling of synoptic wind. Drainage wind averaging 2.5 m s -1 was found to exist in a surface layer not greater than 200 m deep on 60% of the nights investigated. This frequently occurring drainage flow is characterized by a strong decoupling from the upper level winds. Daytime winds, on the other hand, are representative of the synoptic flow patterns suggesting a rather rapid coupling after sunrise

  4. Characterization of turbidity in Florida's Lake Okeechobee and Caloosahatchee and St. Lucie estuaries using MODIS-Aqua measurements.

    Science.gov (United States)

    Wang, Menghua; Nim, Carl J; Son, Seunghyun; Shi, Wei

    2012-10-15

    This paper describes the use of ocean color remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to characterize turbidity in Lake Okeechobee and its primary drainage basins, the Caloosahatchee and St. Lucie estuaries from 2002 to 2010. Drainage modification and agricultural development in southern Florida transport sediments and nutrients from watershed agricultural areas to Lake Okeechobee. As a result of development around Lake Okeechobee and the estuaries that are connected to Lake Okeechobee, estuarine conditions have also been adversely impacted, resulting in salinity and nutrient fluctuations. The measurement of water turbidity in lacustrine and estuarine ecosystems allows researchers to understand important factors such as light limitation and the potential release of nutrients from re-suspended sediments. Based on a strong correlation between water turbidity and normalized water-leaving radiance at the near-infrared (NIR) band (nL(w)(869)), a new satellite water turbidity algorithm has been developed for Lake Okeechobee. This study has shown important applications with satellite-measured nL(w)(869) data for water quality monitoring and measurements for turbid inland lakes. MODIS-Aqua-measured water property data are derived using the shortwave infrared (SWIR)-based atmospheric correction algorithm in order to remotely obtain synoptic turbidity data in Lake Okeechobee and normalized water-leaving radiance using the red band (nL(w)(645)) in the Caloosahatchee and St. Lucie estuaries. We found varied, but distinct seasonal, spatial, and event driven turbidity trends in Lake Okeechobee and the Caloosahatchee and St. Lucie estuary regions. Wind waves and hurricanes have the largest influence on turbidity trends in Lake Okeechobee, while tides, currents, wind waves, and hurricanes influence the Caloosahatchee and St. Lucie estuarine areas. Published by Elsevier Ltd.

  5. A mass balance mercury budget for a mine-dominated lake: Clear Lake, California

    Science.gov (United States)

    Suchanek, T.H.; Cooke, J.; Keller, K.; Jorgensen, S.; Richerson, P.J.; Eagles-Smith, Collin A.; Harner, E.J.; Adam, D.P.

    2009-01-01

    The Sulphur Bank Mercury Mine (SBMM), active intermittently from 1873–1957 and now a USEPA Superfund site, was previously estimated to have contributed at least 100 metric tons (105 kg) of mercury (Hg) into the Clear Lake aquatic ecosystem. We have confirmed this minimum estimate. To better quantify the contribution of the mine in relation to other sources of Hg loading into Clear Lake and provide data that might help reduce that loading, we analyzed Inputs and Outputs of Hg to Clear Lake and Storage of Hg in lakebed sediments using a mass balance approach. We evaluated Inputs from (1) wet and dry atmospheric deposition from both global/regional and local sources, (2) watershed tributaries, (3) groundwater inflows, (4) lakebed springs and (5) the mine. Outputs were quantified from (1) efflux (volatilization) of Hg from the lake surface to the atmosphere, (2) municipal and agricultural water diversions, (3) losses from out-flowing drainage of Cache Creek that feeds into the California Central Valley and (4) biotic Hg removal by humans and wildlife. Storage estimates include (1) sediment burial from historic and prehistoric periods (over the past 150–3,000 years) from sediment cores to ca. 2.5m depth dated using dichloro diphenyl dichloroethane (DDD), 210Pb and 14C and (2) recent Hg deposition in surficial sediments. Surficial sediments collected in October 2003 (11 years after mine site remediation) indicate no reduction (but a possible increase) in sediment Hg concentrations over that time and suggest that remediation has not significantly reduced overall Hg loading to the lake. Currently, the mine is believed to contribute ca. 322–331 kg of Hg annually to Clear Lake, which represents ca. 86–99% of the total Hg loading to the lake. We estimate that natural sedimentation would cover the existing contaminated sediments within ca. 150–300 years.

  6. Spatial and historical distribution of organic phosphorus driven by environment conditions in lake sediments.

    Science.gov (United States)

    Lü, Changwei; He, Jiang; Wang, Bing

    2018-02-01

    The chemistry of sedimentary organic phosphorus (OP) and its fraction distribution in sediments are greatly influenced by environmental conditions such as terrestrial inputs and runoffs. The linkage of OP with environmental conditions was analyzed on the basis of OP spatial and historical distributions in lake sediments. The redundancy analysis and OP spatial distribution results suggested that both NaOH-OP (OP extracted by NaOH) and Re-OP (residual OP) in surface sediments from the selected 13 lakes reflected the gradient effects of environmental conditions and the autochthonous and/or allochthonous inputs driven by latitude zonality in China. The lake level and salinity of Lake Hulun and the runoff and precipitation of its drainage basin were reconstructed on the basis of the geochemistry index. This work showed that a gradient in weather conditions presented by the latitude zonality in China impacts the OP accumulation through multiple drivers and in many ways. The drivers are mainly precipitation and temperature, governing organic matter (OM) production, degradation rate and transportation in the watershed. Over a long temporal dimension (4000years), the vertical distributions of Re-OP and NaOH-OP based on a dated sediment profile from HLH were largely regulated by the autochthonous and/or allochthonous inputs, which depended on the environmental and climate conditions and anthropogenic activities in the drainage basin. This work provides useful environmental geochemistry information to understand the inherent linkage of OP fractionation with environmental conditions and lake evolution. Copyright © 2017. Published by Elsevier B.V.

  7. A modified QWASI model for fate and transport modeling of mercury between the water-ice-sediment in Lake Ulansuhai.

    Science.gov (United States)

    Liu, Yu; Li, Changyou; Anderson, Bruce; Zhang, Sheng; Shi, Xiaohong; Zhao, Shengnan

    2017-06-01

    Mercury contamination from industrial and agricultural drainage into lakes and rivers is a growing concern in Northern China. Lake Ulansuhai, located in Hetao irrigation district in Inner Mongolia, is the only sink for the all industrial and agricultural drainage and sole outlet for this district to the Yellow River, which is one of the main source of drinking water for the numerous cities and towns downstream. Because Ulansuahi is ice-covered during winter, the QWASI model was modified by adding an ice equation to get a more accurate understanding of the fate and transport of mercury within the lake. Both laboratory and field tests were carried out during the ice growth period. The aquivalence and mass balance approaches were used to develop the modified QWASI + ice model. The margins of error between the modelled and the measured average concentrations of Hg in ice, water, and sediment were 30%, 26.2%, and 19.8% respectively. These results suggest that the new QWASI + ice model could be used to more accurately represent the fate and transport of mercury in the seasonally ice-covered lakes, during the ice growth period. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Biology and chemistry of tree Pennsylvania lakes: responses to acid precipitation. [Lepomis gibbosus; Lepomis machrochirous

    Energy Technology Data Exchange (ETDEWEB)

    Bradt, P.T.; Dudley, J.L.; Berg, M.B.; Barrasso, D.S.

    1986-01-01

    The biology and chemistry of three northeastern Pennsylvania lakes was studied from summer 1981 through summer 1983 to evaluate lakes with different sensitivities to acidification. At the acidifies lake (total alkalinity par. delta 0.0 ..mu..eq L/sup -1/) there were fewer phytoplankton and zooplankton species than at the moderately sensitive lakes. The most numerous plankton species in all three lakes are reportedly acid tolerant. Among the benthic macro- invertebrates (BMI) there were more acid tolerant Chironomidae at the acidified lake, but more acid intolerant Ephemeroptera and Mollusca and a higher wet weight at the least sensitive lake. There were no differences among the lakes' BMI mean total numbers or mean number of taxa. The fish community at the acidified lake was dominated by stunted Lepomis gibbosus, but L. machrochirous were most abundant in the other lakes. Principal component analysis suggested a shift in all three lakes over the sampling period toward combined lower pH, alkalinity, specific conductance, Ca, and Mg and higher Al and Mn. Such chemical changes have been associated with acidification. The rate and extent of acidification appeared to be controlled by geological and hydrological characteristics of the drainage basins.

  9. Peritoneal Drainage Versus Pleural Drainage After Pediatric Cardiac Surgery.

    Science.gov (United States)

    Gowda, Keshava Murty Narayana; Zidan, Marwan; Walters, Henry L; Delius, Ralph E; Mastropietro, Christopher W

    2014-07-01

    We aimed to determine whether infants undergoing cardiac surgery would more efficiently attain negative fluid balance postoperatively with passive peritoneal drainage as compared to traditional pleural drainage. A prospective, randomized study including children undergoing repair of tetralogy of Fallot (TOF) or atrioventricular septal defect (AVSD) was completed between September 2011 and June 2013. Patients were randomized to intraoperative placement of peritoneal catheter or right pleural tube in addition to the requisite mediastinal tube. The primary outcome measure was fluid balance at 48 hours postoperatively. Variables were compared using t tests or Fisher exact tests as appropriate. A total of 24 patients were enrolled (14 TOF and 10 AVSD), with 12 patients in each study group. Mean fluid balance at 48 hours was not significantly different between study groups, -41 ± 53 mL/kg in patients with periteonal drainage and -9 ± 40 mL/kg in patients with pleural drainage (P = .10). At 72 hours however, postoperative fluid balance was significantly more negative with peritoneal drainage, -52.4 ± 71.6 versus +2.0 ± 50.6 (P = .04). On subset analysis, fluid balance at 48 hours in patients with AVSD was more negative with peritoneal drainage as compared to pleural, -82 ± 51 versus -1 ± 38 mL/kg, respectively (P = .02). Fluid balance at 48 hours in patients with TOF was not significantly different between study groups. Passive peritoneal drainage may more effectively facilitate negative fluid balance when compared to pleural drainage after pediatric cardiac surgery, although this benefit is not likely universal but rather dependent on the patient's underlying physiology. © The Author(s) 2014.

  10. Hinterland drainage closure and lake formation in response to middle Eocene Farallon slab removal, Nevada, U.S.A.

    Science.gov (United States)

    Smith, M. Elliot; Cassel, Elizabeth J.; Jicha, Brian R.; Singer, Brad S.; Canada, Andrew S.

    2017-12-01

    ash beds in the Dead Horse Formation at Copper Basin in northern Elko County indicate intermittent ash bed deposition between 45.2 Ma and 38.6 Ma, and an episode of lacustrine deposition between 39.8 Ma and 38.6 Ma that post-dates the main phase of Lake Elko. δD values of volcanic glass sampled from dated ash beds reflect changes in the hydrogen isotope compositions of local Eocene waters, and systematically vary by 80-102‰ according to their depositional environment. The Elko Formation and overlying volcanic strata are overlain regionally by a pronounced unconformity of ∼20 m.y. In the Copper Basin area, deposition continued locally into the Oligocene in the hanging wall of a ductile detachment. The geochronologic and isotopic framework presented here permits reanalysis of the Piñon Range carbonate proxy record that was previously interpreted to record both regional uplift and the middle Eocene climatic optimum. New data suggest instead that isotope values of hydration waters within the Elko Formation were strongly influenced by evaporation, and a change from lacustrine to non-lacustrine conditions can account for the δ18O shift that was interpreted to reflect regional uplift. Moreover, the end of Elko Formation deposition predated the middle Eocene climatic optimum. We interpret the overall record of drainage ponding and paleovalley inundation, progressively more evaporative lacustrine conditions, increasingly proximal volcanism, and subsequent prolonged unconformity to reflect the surface effects of progressive NE to SW removal of the Farallon slab.

  11. Uranium distribution in relation to sedimentary facies, Kern Lake, California

    International Nuclear Information System (INIS)

    Merifield, P.M.; Carlisle, D.; Idiz, E.; Anderhalt, R.; Reed, W.E.; Lamar, D.L.

    1980-04-01

    Kern Lake has served as a sink for drainage from the southern Sierra Nevada and, in lesser amounts, from the southern Temblor Range. Both areas contain significant uranium source rocks. The uranium content in Holocene Kern Lake sediments correlates best with the mud (silt and clay) fraction. It correlates less well with organic carbon. Biotite grains could account for much of the uranium in the sand fraction, and perhaps the silt fraction as well. The data suggest that fixation of uranium by adsorption on mineral grains is a dominant process in this lake system. Further work is required to determine the importance of cation-exchange of uranium on clays and micas and of organically complexed uranium adsorbed to mineral surfaces. These findings also raise the question of whether uranium transport down the Kern River occurs largely as uranium adsorbed to mineral surfaces

  12. Water Balance and Level Change of Lake Babati, Tanzania: Sensitivity to Hydroclimatic Forcings

    Directory of Open Access Journals (Sweden)

    René P. Mbanguka

    2016-12-01

    Full Text Available We develop and present a novel integrated water balance model that accounts for lake water—groundwater interactions, and apply it to the semi-closed freshwater Lake Babati system, Northern Tanzania, East Africa. The model was calibrated and used to evaluate the lake level sensitivity to changes in key hydro-climatic variables such as temperature, precipitation, humidity and cloudiness. The lake response to the Coupled Model Intercomparison Project, Phase 5 (CMIP5 output on possible future climate outcomes was evaluated, an essential basis in understanding future water security and flooding risk in the region. Results show high lake level sensitivity to cloudiness. Increased focus on cloud fraction measurement and interpretation could likely improve projections of lake levels and surface water availability. Modelled divergent results on the future (21st century development of Lake Babati can be explained by the precipitation output variability of CMIP5 models being comparable to the precipitation change needed to drive the water balance model from lake dry-out to overflow; this condition is likely shared with many other East African lake systems. The developed methodology could be useful in investigations on change-driving processes in complex climate—drainage basin—lake systems, which are needed to support sustainable water resource planning in data scarce tropical Africa.

  13. Mine drainage treatment

    OpenAIRE

    Golomeova, Mirjana; Zendelska, Afrodita; Krstev, Boris; Golomeov, Blagoj; Krstev, Aleksandar

    2012-01-01

    Water flowing from underground and surface mines and contains high concentrations of dissolved metals is called mine drainage. Mine drainage can be categorized into several basic types by their alkalinity or acidity. Sulfide rich and carbonate poor materials are expected to produce acidic drainage, and alkaline rich materials, even with significant sulfide concentrations, often produce net alkaline water. Mine drainages are dangerous because pollutants may decompose in the environment. In...

  14. Cluster regression model and level fluctuation features of Van Lake, Turkey

    Directory of Open Access Journals (Sweden)

    Z. Şen

    1999-02-01

    Full Text Available Lake water levels change under the influences of natural and/or anthropogenic environmental conditions. Among these influences are the climate change, greenhouse effects and ozone layer depletions which are reflected in the hydrological cycle features over the lake drainage basins. Lake levels are among the most significant hydrological variables that are influenced by different atmospheric and environmental conditions. Consequently, lake level time series in many parts of the world include nonstationarity components such as shifts in the mean value, apparent or hidden periodicities. On the other hand, many lake level modeling techniques have a stationarity assumption. The main purpose of this work is to develop a cluster regression model for dealing with nonstationarity especially in the form of shifting means. The basis of this model is the combination of transition probability and classical regression technique. Both parts of the model are applied to monthly level fluctuations of Lake Van in eastern Turkey. It is observed that the cluster regression procedure does preserve the statistical properties and the transitional probabilities that are indistinguishable from the original data.Key words. Hydrology (hydrologic budget; stochastic processes · Meteorology and atmospheric dynamics (ocean-atmosphere interactions

  15. Cluster regression model and level fluctuation features of Van Lake, Turkey

    Directory of Open Access Journals (Sweden)

    Z. Şen

    Full Text Available Lake water levels change under the influences of natural and/or anthropogenic environmental conditions. Among these influences are the climate change, greenhouse effects and ozone layer depletions which are reflected in the hydrological cycle features over the lake drainage basins. Lake levels are among the most significant hydrological variables that are influenced by different atmospheric and environmental conditions. Consequently, lake level time series in many parts of the world include nonstationarity components such as shifts in the mean value, apparent or hidden periodicities. On the other hand, many lake level modeling techniques have a stationarity assumption. The main purpose of this work is to develop a cluster regression model for dealing with nonstationarity especially in the form of shifting means. The basis of this model is the combination of transition probability and classical regression technique. Both parts of the model are applied to monthly level fluctuations of Lake Van in eastern Turkey. It is observed that the cluster regression procedure does preserve the statistical properties and the transitional probabilities that are indistinguishable from the original data.

    Key words. Hydrology (hydrologic budget; stochastic processes · Meteorology and atmospheric dynamics (ocean-atmosphere interactions

  16. [Microeukaryotic biodiversity in the waste ore samples surrounding an acid mine drainage lake].

    Science.gov (United States)

    Li, Si-Yuan; Hao, Chun-Bo; Wang, Li-Hua; Lü, Zheng; Zhang, Li-Na; Liu, Ying; Feng, Chuan-Ping

    2013-10-01

    The abandoned mineral samples were collected in an acid mine drainage area in Anhui Province. Molecular ecological methods were used to construct 18S rDNA clone libraries after analyzing the main physicochemical parameters, and then the microeukaryotic diversity and community structure in the acid mine drainage area were studied. The results showed that the region was strongly acidic (pH <3), and the concentrations of Fe, SO2-(4), P, NO-(3) -N showed the same trend, all higher in the bare waste ore samples PD and 1 M than in the vegetation covered samples LW and XC. Four eukaryotic phyla were detected in the abandoned mineral samples: Ascomycota, Basidiomycota, Glomeromycota and Arthropoda. Glomeromycota can form an absolute symbiotic relationship with the plant, and it was a key factor for early plant to adapt the terrestrial environment. The biodiversity of the vegetation covered samples LW and XC, which contained Glomeromycota, was much higher than that of the bare abandoned rock samples PD and 1 M. Moreover, many sequences in the libraries were closely related to some isolated strains, which are tolerant to low pH and heavy metals, such as Penicillium purpurogenum, Chaetothyriales sp. and Staninwardia suttonii.

  17. Simulation of climate-change effects on streamflow, lake water budgets, and stream temperature using GSFLOW and SNTEMP, Trout Lake Watershed, Wisconsin

    Science.gov (United States)

    Hunt, Randall J.; Walker, John F.; Selbig, William R.; Westenbroek, Stephen M.; Regan, R. Steve

    2013-01-01

    -fed systems. Seepage lakes showed larger forecast stage declines related to climate change than did drainage lakes (lakes with outlet streams). Seepage lakes higher in the watershed (nearer to groundwater divides) had less groundwater inflow and thus had larger forecast declines in lake stage; however, ground-water inflow to seepage lakes in general tended to increase as a fraction of the lake budgets with lake-stage decline because inward hydraulic gradients increased. Drainage lakes were characterized by less simulated stage decline as reductions in outlet streamflow of set losses to other water flows. Net groundwater inflow tended to decrease in drainage lakes over the scenario period. Simulated stream temperatures increased appreciably with climate change. The estimated increase in annual average temperature ranged from approximately 1 to 2 degrees Celsius by 2100 in the stream characterized by a high groundwater inflow rate and 2 to 3 degrees Celsius in the stream with a lower rate. The climate drivers used for the climate-change scenarios had appreciable variation between the General Circulation Model and emission scenario selected; this uncertainty was reflected in hydrologic flow and temperature model results. Thus, as with all forecasts of this type, the results are best considered to approximate potential outcomes of climate change.

  18. Anthropogenic modifications to drainage conditions on streamflow variability in the Wabash River basin, Indiana

    Science.gov (United States)

    Chiu, C.; Bowling, L. C.

    2011-12-01

    The Wabash River watershed is the largest watershed in Indiana and includes the longest undammed river reach east of the Mississippi River. The land use of the Wabash River basin began to significantly change from mixed woodland dominated by small lakes and wetlands to agriculture in the mid-1800s and agriculture is now the predominant land use. Over 80% of natural wetland areas were drained to facilitate better crop production through both surface and subsurface drainage applications. Quantifying the change in hydrologic response in this intensively managed landscape requires a hydrologic model that can represent wetlands, crop growth, and impervious area as well as subsurface and surface drainage enhancements, coupled with high resolution soil and topographic inputs. The Variable Infiltration Capacity (VIC) model wetland algorithm has been previously modified to incorporate spatially-varying estimates of water table distribution using a topographic index approach, as well as a simple urban representation. Now, the soil water characteristics curve and a derived drained to equilibrium moisture profile are used to improve the model's estimation of the water table. In order to represent subsurface (tile) drainage, the tile drainage component of subsurface flow is calculated when the simulated water table rises above a specified drain depth. A map of the current estimated extent of subsurface tile drainage for the Wabash River based on a decision tree classifier of soil drainage class, soil slope and agricultural land use is used to activate the new tile drainage feature in the VIC model, while wetland depressional storage capacity is extracted from digital elevation and soil information. This modified VIC model is used to evaluate the performance of model physical variations in the intensively managed hydrologic regime of the Wabash River system and to understand the role of surface and subsurface storage, and land use and land cover change on hydrologic change.

  19. Fluctuations of Lake Eyre, South Australia

    Science.gov (United States)

    2002-01-01

    Lake Eyre is a large salt lake situated between two deserts in one of Australia's driest regions. However, this low-lying lake attracts run-off from one of the largest inland drainage systems in the world. The drainage basin is very responsive to rainfall variations, and changes dramatically with Australia's inter-annual weather fluctuations. When Lake Eyre fills,as it did in 1989, it is temporarily Australia's largest lake, and becomes dense with birds, frogs and colorful plant life. The Lake responds to extended dry periods (often associated with El Nino events) by drying completely.These four images from the Multi-angle Imaging SpectroRadiometer contrast the lake area at the start of the austral summers of 2000 and 2002. The top two panels portray the region as it appeared on December 9, 2000. Heavy rains in the first part of 2000 caused both the north and south sections of the lake to fill partially and the northern part of the lake still contained significant standing water by the time these data were acquired. The bottom panels were captured on November 29, 2002. Rainfall during 2002 was significantly below average ( http://www.bom.gov.au/ ), although showers occurring in the week before the image was acquired helped alleviate this condition slightly.The left-hand panels portray the area as it appeared to MISR's vertical-viewing (nadir) camera, and are false-color views comprised of data from the near-infrared, green and blue channels. Here, wet and/or moist surfaces appear blue-green, since water selectively absorbs longer wavelengths such as near-infrared. The right-hand panels are multi-angle composites created with red band data from MISR's 60-degree forward, nadir and 60-degree backward-viewing cameras, displayed as red, green and blue, respectively. In these multi-angle composites, color variations serve as a proxy for changes in angular reflectance, and indicate textural properties of the surface related to roughness and/or moisture content.Data from

  20. Wisconsin's Lake Superior Basin Water Quality Study. Supplement. Technical Report No. 2.

    Science.gov (United States)

    Whisnant, David M., Ed.

    During the period extending from May 1972 through April 1973, an investigation of the overall water quality conditions of streams flowing into Lake Superior from the entire state of Wisconsin was conducted. The goal of this publication was to provide much needed regional information on water quality, drainage basins, pollution sources and loads,…

  1. Study on the relationship between the lake area variations of Qinghai-Tibetan Plateau and the corresponding climate change in their basins

    Science.gov (United States)

    Guozhuang, Shen; Jingjuan, Liao; Huadong, Guo; Yingkui, Li

    2014-03-01

    Qinghai-Tibetan Plateau is the largest lake area in China, with a total area of existing lakes of 36,900km2, accounting for 52% of the total lake area of China. Lakes on the Tibetan Plateau play critical roles in the water cycle and ecological and environment systems of the Plateau. The global trend of warming up is increasing obviously, which has led to major changes in the climate conditions in China, even in the world. Whereas, when they analyse the relationship they just use the weather station's recording data, without any spatial analysis of the climate data. Here, we will do some researches on the relationship between the 10 selected lakes' area variation and the corresponding climate change in their drainage basin and discuss how the lakes changes in recent 40 years using the climate data processed using the spatial kriging. Thus, the drainage area can be taken into account and a real relationship can be pointed out. In order to study the relationship, Landsat MSS data, Landsat TM, Landsat ETM images, the topographic map have been collected to extract the variation of lake area. The 131 weather stations climate data, including precipitation, temperature, sun shine duration, evaporation are chosen to study the relationship. After extraction of the area of the lakes, a multivariate statistical analysis method was used to test the relationship between the area of the lakes and the global climate change, including the change of the temperature, the precipitation, and other factors. The variation of lakes in Qinghai-Tibetan Plateau is related to the mean temperature, the precipitation and saturation vapour pressure. But the frozen soil may affect the lake area variation to some extent.

  2. Study on the relationship between the lake area variations of Qinghai-Tibetan Plateau and the corresponding climate change in their basins

    International Nuclear Information System (INIS)

    Guozhuang, Shen; Jingjuan, Liao; Huadong, Guo; Yingkui, Li

    2014-01-01

    Qinghai-Tibetan Plateau is the largest lake area in China, with a total area of existing lakes of 36,900km 2 , accounting for 52% of the total lake area of China. Lakes on the Tibetan Plateau play critical roles in the water cycle and ecological and environment systems of the Plateau. The global trend of warming up is increasing obviously, which has led to major changes in the climate conditions in China, even in the world. Whereas, when they analyse the relationship they just use the weather station's recording data, without any spatial analysis of the climate data. Here, we will do some researches on the relationship between the 10 selected lakes' area variation and the corresponding climate change in their drainage basin and discuss how the lakes changes in recent 40 years using the climate data processed using the spatial kriging. Thus, the drainage area can be taken into account and a real relationship can be pointed out. In order to study the relationship, Landsat MSS data, Landsat TM, Landsat ETM images, the topographic map have been collected to extract the variation of lake area. The 131 weather stations climate data, including precipitation, temperature, sun shine duration, evaporation are chosen to study the relationship. After extraction of the area of the lakes, a multivariate statistical analysis method was used to test the relationship between the area of the lakes and the global climate change, including the change of the temperature, the precipitation, and other factors. The variation of lakes in Qinghai-Tibetan Plateau is related to the mean temperature, the precipitation and saturation vapour pressure. But the frozen soil may affect the lake area variation to some extent

  3. WATER DRAINAGE MODEL

    International Nuclear Information System (INIS)

    Case, J.B.

    2000-01-01

    The drainage of water from the emplacement drift is essential for the performance of the EBS. The unsaturated flow properties of the surrounding rock matrix and fractures determine how well the water will be naturally drained. To enhance natural drainage, it may be necessary to introduce engineered drainage features (e.g. drilled holes in the drifts), that will ensure communication of the flow into the fracture system. The purpose of the Water Drainage Model is to quantify and evaluate the capability of the drift to remove water naturally, using the selected conceptual repository design as a basis (CRWMS M andO, 1999d). The analysis will provide input to the Water Distribution and Removal Model of the EBS. The model is intended to be used to provide postclosure analysis of temperatures and drainage from the EBS. It has been determined that drainage from the EBS is a factor important to the postclosure safety case

  4. Reducing nitrate loss in tile drainage water with cover crops and water-table management systems.

    Science.gov (United States)

    Drury, C F; Tan, C S; Welacky, T W; Reynolds, W D; Zhang, T Q; Oloya, T O; McLaughlin, N B; Gaynor, J D

    2014-03-01

    Nitrate lost from agricultural soils is an economic cost to producers, an environmental concern when it enters rivers and lakes, and a health risk when it enters wells and aquifers used for drinking water. Planting a winter wheat cover crop (CC) and/or use of controlled tile drainage-subirrigation (CDS) may reduce losses of nitrate (NO) relative to no cover crop (NCC) and/or traditional unrestricted tile drainage (UTD). A 6-yr (1999-2005) corn-soybean study was conducted to determine the effectiveness of CC+CDS, CC+UTD, NCC+CDS, and NCC+UTD treatments for reducing NO loss. Flow volume and NO concentration in surface runoff and tile drainage were measured continuously, and CC reduced the 5-yr flow-weighted mean (FWM) NO concentration in tile drainage water by 21 to 38% and cumulative NO loss by 14 to 16% relative to NCC. Controlled tile drainage-subirrigation reduced FWM NO concentration by 15 to 33% and cumulative NO loss by 38 to 39% relative to UTD. When CC and CDS were combined, 5-yr cumulative FWM NO concentrations and loss in tile drainage were decreased by 47% (from 9.45 to 4.99 mg N L and from 102 to 53.6 kg N ha) relative to NCC+UTD. The reductions in runoff and concomitant increases in tile drainage under CC occurred primarily because of increases in near-surface soil hydraulic conductivity. Cover crops increased corn grain yields by 4 to 7% in 2004 increased 3-yr average soybean yields by 8 to 15%, whereas CDS did not affect corn or soybean yields over the 6 yr. The combined use of a cover crop and water-table management system was highly effective for reducing NO loss from cool, humid agricultural soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  5. Application of digital image processing techniques and information systems to water quality monitoring of Lake Tahoe

    Science.gov (United States)

    Smith, A. Y.; Blackwell, R. J.

    1981-01-01

    The Tahoe basin occupies over 500 square miles of territory located in a graben straddling the boundary between California and Nevada. Lake Tahoe contains 126 million acre-feet of water. Since the 1950's the basin has experienced an ever increasing demand for land development at the expense of the natural watershed. Discharge of sediment to the lake has greatly increased owing to accelerated human interference, and alterations to the natural drainage patterns are evident in some areas. In connection with an investigation of the utility of a comprehensive system that takes into account the causes as well as the effects of lake eutrophication, it has been attempted to construct an integrated and workable data base, comprised of currently available data sources for the Lake Tahoe region. Attention is given to the image based information system (IBIS), the construction of the Lake Tahoe basin data base, and the application of the IBIS concept to the Lake Tahoe basin.

  6. Glacier Instability, Rapid Glacier Lake Growth and Related Hazards at Belvedere Glacier, Macugnaga, Italy

    Science.gov (United States)

    Huggel, C.; Kaeaeb, A.; Haeberli, W.; Mortara, G.; Chiarle, M.; Epifani, F.

    2002-12-01

    Starting in summer 2000, Belvedere Glacier, near Macugnaga, Italian Alps, developed an extraordinary change in flow, geometry and surface appearance. A surge-type flow acceleration started in the lower parts of the Monte-Rosa east face, leading to strong crevassing and deformation of Belvedere Glacier, accompanied by bulging of its orographic right margin. In September 2001, a small supraglacial lake developed on the glacier. High water pressure and accelerated movement lasted into winter 2001/2002. The ice, in places, started to override moraines from the Little Ice Age. In late spring and early summer 2002, the supraglacial lake grew at extraordinary rates reaching a maximum area of more than 150'000 m2 by end of June. The evolution of such a large supraglacial lake, a rather unique feature in the Alps, was probably enabled by changes in the subglacial drainage system in the course of the surge-like developments with high water pressure in the glacier. At the end of June, an enhanced growth of the lake level with a rise of about 1 m per day was observed such that the supraglacial lake became a urgent hazard problem for the community of Macugnaga. Emergency measures had to be taken by the Italian Civil Protection. The authors thereby acted as the official expert advisers. Temporal evacuations were ordered and a permanent monitoring and alarm system was installed. Pumps with a maximum output of 1 m3/s were brought to the lake. Bathymetric studies yielded a maximum lake depth of 55 m and a volume of 3.3 millions of cubic meters of water. Aerial photography of 1995, 1999, September 2001 and October 2001 was used to calculate ice flow velocities and changes in surface altitude. Compared to the period of 1995 to 1999, the flow accelerated by about five times in 2001 (max. speeds up to 200 m/yr). Surface uplift measured was about 10-15 m/yr. The results of the photogrammetric studies were used to evaluate different possible lake-outburst scenarios, in particular

  7. Hydrologic Monitoring and Water Balance Modeling in West and Seven Palm Lake Drainages in the Florida Everglades

    Science.gov (United States)

    Allen, J.; Whitman, D.; Price, R.

    2016-02-01

    In the Florida Everglades, sea level rise and reduced freshwater inputs have altered the hydrologic and chemical conditions in coastal estuaries. Brackish coastal groundwater discharge, an inland intrusion of submarine groundwater discharge, has been shown to occur seasonally along the coastal wetlands of the Everglades. This brackish groundwater is enriched in total phosphorus, the limiting nutrient in the Everglades. A major component of the Comprehensive Everglades Restoration Plan is to increase freshwater delivery to the southern coastal Everglades and adjacent bays, in an effort to restore a salinity and nutrient regime conducive for the development of submerged aquatic vegetation. This study is being conducted in the estuarine lakes of the Everglades that are connected to Florida Bay. Water quality in these lakes has diminished over time, potentially due to increased nutrient deliveries from coastal groundwater discharge. Current hydrologic and chemical conditions are being established within the lakes in order to gain a better understanding of the effects of restoration efforts through time. Water budgets are being constructed on daily, monthly and annual time steps to estimate the groundwater-surface water interaction term. In addition, hydrologic and topographic data from the Everglades Depth Estimation Network is being utilized in order to calculate water budgets for the lakes region spanning ten years prior to the study period. Water chemistry in the lakes and groundwater is also being monitored to determine the influence of groundwater-surface water exchange on salinity and nutrient conditions in the lakes. The results of this study can be used to assess the influence of restoration efforts on the hydrochemical conditions of downstream coastal areas affected by coastal groundwater discharge and sea level rise.

  8. Hydrological modeling of the pipestone creek watershed using the Soil Water Assessment Tool (SWAT: Assessing impacts of wetland drainage on hydrology

    Directory of Open Access Journals (Sweden)

    Cesar Perez-Valdivia

    2017-12-01

    Full Text Available Study region: Prairie Pothole Region of North America. Study focus: The Prairie Pothole Region of North America has experienced extensive wetland drainage, potentially impacting peak flows and annual flow volumes. Some of this drainage has occurred in closed basins, possibly impacting lake water levels of these systems. In this study we investigated the potential impact of wetland drainage on peak flows and annual volumes in a 2242 km2 watershed located in southeastern Saskatchewan (Canada using the Soil Water Assessment Tool (SWAT model. New hydrological insights: The SWAT model, which had been calibrated and validated at daily and monthly time steps for the 1997–2009 period, was used to assess the impact of wetland drainage using three hypothetical scenarios that drained 15, 30, and 50% of the non-contributing drainage area. Results of these simulations suggested that drainage increased spring peak flows by about 50, 79 and 113%, respectively while annual flow volumes increased by about 43, 68, and 98% in each scenario. Years that were wetter than normal presented increased peak flows and annual flow volumes below the average of the simulated period. Alternatively, summer peak flows presented smaller increases in terms of percentages during the simulated period. Keywords: Soil Water Assessment Tool (SWAT, Wetland drainage, Peak flow, Annual volume, Prairie Pothole Region

  9. Landsat-based trend analysis of lake dynamics across northern permafrost regions

    Science.gov (United States)

    Nitze, Ingmar; Grosse, Guido; Jones, Benjamin M.; Arp, Christopher D.; Ulrich, Mathias; Federov, Alexander; Veremeeva, Alexandra

    2017-01-01

    Lakes are a ubiquitous landscape feature in northern permafrost regions. They have a strong impact on carbon, energy and water fluxes and can be quite responsive to climate change. The monitoring of lake change in northern high latitudes, at a sufficiently accurate spatial and temporal resolution, is crucial for understanding the underlying processes driving lake change. To date, lake change studies in permafrost regions were based on a variety of different sources, image acquisition periods and single snapshots, and localized analysis, which hinders the comparison of different regions. Here we present, a methodology based on machine-learning based classification of robust trends of multi-spectral indices of Landsat data (TM,ETM+, OLI) and object-based lake detection, to analyze and compare the individual, local and regional lake dynamics of four different study sites (Alaska North Slope, Western Alaska, Central Yakutia, Kolyma Lowland) in the northern permafrost zone from 1999 to 2014. Regional patterns of lake area change on the Alaska North Slope (-0.69%), Western Alaska (-2.82%), and Kolyma Lowland (-0.51%) largely include increases due to thermokarst lake expansion, but more dominant lake area losses due to catastrophic lake drainage events. In contrast, Central Yakutia showed a remarkable increase in lake area of 48.48%, likely resulting from warmer and wetter climate conditions over the latter half of the study period. Within all study regions, variability in lake dynamics was associated with differences in permafrost characteristics, landscape position (i.e. upland vs. lowland), and surface geology. With the global availability of Landsat data and a consistent methodology for processing the input data derived from robust trends of multi-spectral indices, we demonstrate a transferability, scalability and consistency of lake change analysis within the northern permafrost region.

  10. Sedimentation and chemical quality of surface water in the Heart River drainage basin, North Dakota

    Science.gov (United States)

    Maderak, Marion L.

    1966-01-01

    The Heart River drainage basin of southwestern North Dakota comprises an area of 3,365 square miles and lies within the Missouri Plateau of the Great Plains province. Streamflow of the Heart River and its tributaries during 1949-58 was directly proportional to .the drainage area. After the construction of Heart Butte Dam in 1949 and Dickinson Dam in 1950, the mean annual streamflow near Mandan was decreased an estimated 10 percent by irrigation, evaporation from the two reservoirs, and municipal use. Processes that contribute sediment to the Heart River are mass wasting, advancement of valley heads, and sheet, lateral stream, and gully erosion. In general, glacial deposits, terraces, and bars of Quaternary age are sources of sand and larger sediment, and the rocks of Tertiary age are sources of clay, silt. and sand. The average annual suspended-sediment discharges near Mandan were estimated to be 1,300,000 tons for 1945-49 and 710,000 tons for 1970-58. The percentage composition of ions in water of the Heart River, based on average concentrations in equivalents per million for selected ranges of streamflow, changes with flow and from station to station. During extremely low flows the water contains a large percentage of sodium and about equal percentages of bicarbonate and .sulfate, and during extremely high flows the water contains a large percentage of calcium plus magnesium and bicarbonate. The concentrations, in parts per million, of most of the ions vary inversely with flow. The water in the reservoirs--Edward Arthur Patterson Lake and Lake Tschida--during normal or above-normal runoff is of suitable quality for public use. Generally, because of medium or high salinity hazards, the successful long-term use of Heart River water for irrigation will depend on a moderate amount of leaching, adequate drainage, ,and the growing of crops that have moderate or good salt tolerance.

  11. Genetic divergence of a sympatric lake-resident-anadromous three-spined stickleback Gasterosteus aculeatus species pair.

    Science.gov (United States)

    Drevecky, C J; Falco, R; Aguirre, W E

    2013-07-01

    The genetic relationship between sympatric, morphologically divergent populations of anadromous and lake-resident three-spined stickleback Gasterosteus aculeatus in the Jim Creek drainage of Cook Inlet, Alaska, was examined using microsatellite loci and mitochondrial d-loop sequence data. Resident samples differed substantially from sympatric anadromous samples in the Jim Creek drainage with the magnitude of the genetic divergence being similar to that between allopatric resident and anadromous populations in other areas. Resident samples were genetically similar within the Jim Creek drainage, as were the anadromous samples surveyed. Neighbour-joining and Structure cluster analysis grouped the samples into four genetic clusters by ecomorph (anadromous v. all resident) and geographic location of the resident samples (Jim Creek, Mat-Su and Kenai). There was no evidence of hybridization between resident and anadromous G. aculeatus in the Jim Creek drainage, which thus appear to be reproductively isolated. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

  12. Transient drainage summary report

    International Nuclear Information System (INIS)

    1996-09-01

    This report summarizes the history of transient drainage issues on the Uranium Mill Tailings Remedial Action (UMTRA) Project. It defines and describes the UMTRA Project disposal cell transient drainage process and chronicles UMTRA Project treatment of the transient drainage phenomenon. Section 4.0 includes a conceptual cross section of each UMTRA Project disposal site and summarizes design and construction information, the ground water protection strategy, and the potential for transient drainage

  13. Prairie Pothole Region wetlands and subsurface drainage systems: Key factors for determining drainage setback distances

    Science.gov (United States)

    Tangen, Brian; Wiltermuth, Mark T.

    2018-01-01

    Use of agricultural subsurface drainage systems in the Prairie Pothole Region of North America continues to increase, prompting concerns over potential negative effects to the Region's vital wetlands. The U.S. Fish and Wildlife Service protects a large number of wetlands through conservation easements that often utilize standard lateral setback distances to provide buffers between wetlands and drainage systems. Because of a lack of information pertaining to the efficacy of these setback distances for protecting wetlands, information is required to support the decision making for placement of subsurface drainage systems adjacent to wetlands. We used qualitative graphical analyses and data comparisons to identify characteristics of subsurface drainage systems and wetland catchments that could be considered when assessing setback distances. We also compared setback distances with catchment slope lengths to determine if they typically exclude drainage systems from the catchment. We demonstrated that depth of a subsurface drainage system is a key factor for determining drainage setback distances. Drainage systems located closer to the surface (shallow) typically could be associated with shorter lateral setback distances compared with deeper systems. Subsurface drainage systems would be allowed within a wetland's catchment for 44–59% of catchments associated with wetland conservation easements in North Dakota. More specifically, results suggest that drainage setback distances generally would exclude drainage systems from catchments of the smaller wetlands that typically have shorter slopes in the adjacent upland contributing area. For larger wetlands, however, considerable areas of the catchment would be vulnerable to drainage that may affect wetland hydrology. U.S. Fish and Wildlife Service easements are associated with > 2,000 km2 of wetlands in North Dakota, demonstrating great potential to protect these systems from drainage depending on policies for installing

  14. The foam drainage equation for drainage dynamics in unsaturated porous media

    Science.gov (United States)

    Lehmann, P.; Hoogland, F.; Assouline, S.; Or, D.

    2017-07-01

    Similarity in liquid-phase configuration and drainage dynamics of wet foam and gravity drainage from unsaturated porous media expands modeling capabilities for capillary flows and supplements the standard Richards equation representation. The governing equation for draining foam (or a soil variant termed the soil foam drainage equation—SFDE) obviates the need for macroscopic unsaturated hydraulic conductivity function by an explicit account of diminishing flow pathway sizes as the medium gradually drains. The study provides new and simple analytical expressions for drainage rates and volumes from unsaturated porous media subjected to different boundary conditions. Two novel analytical solutions for saturation profile evolution were derived and tested in good agreement with a numerical solution of the SFDE. The study and the proposed solutions rectify the original formulation of foam drainage dynamics of Or and Assouline (2013). The new framework broadens the scope of methods available for quantifying unsaturated flow in porous media, where the intrinsic conductivity and geometrical representation of capillary drainage could improve understanding of colloid and pathogen transport. The explicit geometrical interpretation of flow pathways underlying the hydraulic functions used by the Richards equation offers new insights that benefit both approaches.

  15. Geomorphic and sedimentologic evidence for the separation of Lake Superior from Lake Michigan and Huron

    Science.gov (United States)

    Johnston, J.W.; Thompson, T.A.; Wilcox, D.A.; Baedke, S.J.

    2007-01-01

    A common break was recognized in four Lake Superior strandplain sequences using geomorphic and sedimentologic characteristics. Strandplains were divided into lakeward and landward sets of beach ridges using aerial photographs and topographic surveys to identify similar surficial features and core data to identify similar subsurface features. Cross-strandplain, elevation-trend changes from a lowering towards the lake in the landward set of beach ridges to a rise or reduction of slope towards the lake in the lakeward set of beach ridges indicates that the break is associated with an outlet change for Lake Superior. Correlation of this break between study sites and age model results for the strandplain sequences suggest that the outlet change occurred sometime after about 2,400 calendar years ago (after the Algoma phase). Age model results from one site (Grand Traverse Bay) suggest an alternate age closer to about 1,200 calendar years ago but age models need to be investigated further. The landward part of the strandplain was deposited when water levels were common in all three upper Great Lakes basins (Superior, Huron, and Michigan) and drained through the Port Huron/Sarnia outlet. The lakeward part was deposited after the Sault outlet started to help regulate water levels in the Lake Superior basin. The landward beach ridges are commonly better defined and continuous across the embayments, more numerous, larger in relief, wider, have greater vegetation density, and intervening swales contain more standing water and peat than the lakeward set. Changes in drainage patterns, foreshore sediment thickness and grain size help in identifying the break between sets in the strandplain sequences. Investigation of these breaks may help identify possible gaps in the record or missing ridges in strandplain sequences that may not be apparent when viewing age distributions and may justify the need for multiple age and glacial isostatic adjustment models. ?? 2006 Springer Science

  16. River piracy and drainage basin reorganization led by climate-driven glacier retreat

    Science.gov (United States)

    Shugar, Daniel H.; Clague, John J.; Best, James L.; Schoof, Christian; Willis, Michael J.; Copland, Luke; Roe, Gerard H.

    2017-04-01

    River piracy--the diversion of the headwaters of one stream into another one--can dramatically change the routing of water and sediment, with a profound effect on landscape evolution. Stream piracy has been investigated in glacial environments, but so far it has mainly been studied over Quaternary or longer timescales. Here we document how retreat of Kaskawulsh Glacier--one of Canada's largest glaciers--abruptly and radically altered the regional drainage pattern in spring 2016. We use a combination of hydrological measurements and drone-generated digital elevation models to show that in late May 2016, meltwater from the glacier was re-routed from discharge in a northward direction into the Bering Sea, to southward into the Pacific Ocean. Based on satellite image analysis and a signal-to-noise ratio as a metric of glacier retreat, we conclude that this instance of river piracy was due to post-industrial climate change. Rapid regional drainage reorganizations of this type can have profound downstream impacts on ecosystems, sediment and carbon budgets, and downstream communities that rely on a stable and sustained discharge. We suggest that the planforms of Slims and Kaskawulsh rivers will adjust in response to altered flows, and the future Kaskawulsh watershed will extend into the now-abandoned headwaters of Slims River and eventually capture the Kluane Lake drainage.

  17. Hydroecological condition and potential for aquaculture in lakes of the arid region of Khorezm, Uzbekistan

    Science.gov (United States)

    Crootof, Africa; Mullabaev, Nodirbek; Saito, Laurel; Atwell, Lisa; Rosen, Michael R.; Bekchonova, Marhabo; Ginatullina, Elena; Scott, Julian; Chandra, Sudeep; Nishonov, Bakhriddin; Lamers, John P.A.; Fayzieva, Dilorom

    2015-01-01

    With >400 small (water resources to provide a local food supply could increase fish consumption while improving the rural economy. Hydroecological (biological and physical) and chemical characteristics (including legacy pesticides ΣDDT and ΣHCH) of four representative drainage lakes in Khorezm from 2006 to 2008 were analyzed for the lakes’ capability to support healthy fish populations. Lake characteristics were categorized as “optimal” (having little or no effect on growth and development), “tolerable” (corresponding to chronic or sub-lethal toxicity) and “lethal” (corresponding to acute toxicity). Results indicate that three lakes are likely well-suited for raising fish species, with water quality meeting World Bank aquaculture guidelines. However, the fourth lake often had salinity concentrations > optimal levels for local fish species. Pesticide concentrations in water of all four lakes were within tolerable aquaculture ranges. Although water ΣDDT concentrations were >optimal limits, results from chemical analysis of fish tissues and semi-permeable membrane devices indicated that study lake ΣDDT concentrations were not accumulating in fish or posing a human health threat. Land and water management to maintain adequate lake water quality are imperative for sustaining fish populations for human consumption.

  18. Hydroecological condition and potential for aquaculture in lakes of the arid region of Khorezm, Uzbekistan

    Science.gov (United States)

    Crootof, Africa; Mullabaev, Nodirbek; Saito, Laurel; Atwell, Lisa; Rosen, Michael R.; Bekchonova, Marhabo; Ginatullina, Elena; Scott, Julian; Chandra, Sudeep; Nishonov, Bakhriddin; Lamers, John P.A.; Fayzieva, Dilorom

    2015-01-01

    With >400 small (resources to provide a local food supply could increase fish consumption while improving the rural economy. Hydroecological (biological and physical) and chemical characteristics (including legacy pesticides ΣDDT and ΣHCH) of four representative drainage lakes in Khorezm from 2006 to 2008 were analyzed for the lakes’ capability to support healthy fish populations. Lake characteristics were categorized as “optimal” (having little or no effect on growth and development), “tolerable” (corresponding to chronic or sub-lethal toxicity) and “lethal” (corresponding to acute toxicity). Results indicate that three lakes are likely well-suited for raising fish species, with water quality meeting World Bank aquaculture guidelines. However, the fourth lake often had salinity concentrations > optimal levels for local fish species. Pesticide concentrations in water of all four lakes were within tolerable aquaculture ranges. Although water ΣDDT concentrations were >optimal limits, results from chemical analysis of fish tissues and semi-permeable membrane devices indicated that study lake ΣDDT concentrations were not accumulating in fish or posing a human health threat. Land and water management to maintain adequate lake water quality are imperative for sustaining fish populations for human consumption.

  19. Holocene evolution of the Tonle Sap Lake: valley network infill and rates of sedimentation in Cambodia's Great Lake

    Science.gov (United States)

    Best, J.; Darby, S. E.; Langdon, P. G.; Hackney, C. R.; Leyland, J.; Parsons, D. R.; Aalto, R. E.; Marti, M.

    2017-12-01

    Tonle Sap Lake, the largest freshwater lake in SE Asia (c. 120km long and 35 km wide), is a vital ecosystem that provides 40-60% of the protein for the population of Cambodia. The lake is fed by flow from the Mekong River that causes the lake rise in level by c. 8m during monsoonal and cyclone-related floods, with drainage of the lake following the monsoon. Hydropower dam construction on the Mekong River has raised concerns as to the fragility of the Tonle Sap habitat due to any changing water levels and sedimentation rates within the lake. This paper details results of sub-bottom profiling surveys of Tonle Sap Lake in October 2014 that detailed the stratigraphy of the lake and assessed rates of infill. An Innomar Parametric Echo Sounder (PES) was used to obtain c. 250 km of sub-bottom profiles, with penetration up to 15m below the lake bed at a vertical resolution of c. 0.20m. These PES profiles were linked to cores from the north of the lake and previous literature. The PES profiles reveal a network of valleys, likely LGM, with relief up to c. 15-20m, that have been infilled by a suite of Holocene sediments. The valley surface is picked out as a strong reflector throughout the lake, and displays a series of valleys that are up to c. 15m deep and commonly 50-200m wide, although some of the largest valleys are 1.2km in width. Modelling of channel network incision during LGM conditions generates landscapes consistent with our field observations. The Tonle Sap valley network is infilled by sediments that show firstly fluvial and/or subaerial slope sedimentation, and then by extensive, parallel-bedded, lacustrine sedimentation. Lastly, the top c. 1m of sedimentation is marked by a distinct basal erosional surface that can be traced over much of the Tonle Sap Lake, and that is overlain by a series of parallel PES reflections. This upper sediment layer is interpreted to represent sedimentation in the Tonle Sap lake due to sediment suspension settling but after a period

  20. Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet.

    Science.gov (United States)

    Smith, Laurence C; Chu, Vena W; Yang, Kang; Gleason, Colin J; Pitcher, Lincoln H; Rennermalm, Asa K; Legleiter, Carl J; Behar, Alberto E; Overstreet, Brandon T; Moustafa, Samiah E; Tedesco, Marco; Forster, Richard R; LeWinter, Adam L; Finnegan, David C; Sheng, Yongwei; Balog, James

    2015-01-27

    Thermally incised meltwater channels that flow each summer across melt-prone surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, drainage pattern, and discharge across 6,812 km(2) of southwest Greenland in July 2012, after a record melt event. Efficient surface drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54-2.81 cm⋅d(-1)) indicate that the surface drainage system conveyed its own storage volume every drainage to true outflow from the ice edge. However, Isortoq discharges tended lower than runoff simulations from the Modèle Atmosphérique Régional (MAR) regional climate model (0.056-0.112 km(3)⋅d(-1) vs. ∼0.103 km(3)⋅d(-1)), and when integrated over the melt season, totaled just 37-75% of MAR, suggesting nontrivial subglacial water storage even in this melt-prone region of the ice sheet. We conclude that (i) the interior surface of the ice sheet can be efficiently drained under optimal conditions, (ii) that digital elevation models alone cannot fully describe supraglacial drainage and its connection to subglacial systems, and (iii) that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater export from the ice sheet to the ocean.

  1. A proposal of protection techniques in the catchment of a lake in the context of improving its recreational value

    Directory of Open Access Journals (Sweden)

    Grochowska Jolanta

    2016-12-01

    Full Text Available The study was carried out on Lake Rentyńskie (100.8 ha; 9.4 m situated approximately 20 km to the west of Olsztyn, in the drainage basin of the rivers Giłwa and Pasłęka. The direct catchment area of the lake is 166.2 ha. Forests cover most of the drainage basin area (74%. As revealed in the study, Rentyńskie is a highly eutrophic reservoir. The lake waters were characterized by a high content of nutrients, up to 1.508 mg P dm-3 and 11.7 mg N dm-3. The high fertility of the lake was also evident in the values of chlorophyll a - 75.4 μg dm-3, and low water transparency - average 1 m. The total annual phosphorus and nitrogen load to Lake Rentyńskie, calculated according to Giercuszkiewicz-Bajtlik (1990 equals 759.0 kg of phosphorus and 31869.7 kg of nitrogen, or per unit surface 0.753 g P m-2 yr-1 and 31.611 N m-2 yr-1. Allowable and critical load levels to Lake Rentyńskie calculated according to the hydrological model of Vollenweider (1976 equal (respectively 0.090 g P m-2 yr-1 and 0.189 g P m-2 yr-1. From a comparison between the actual phosphorus load and the values calculated according to Vollenweider it can be concluded that the loads not only exceed the allowable values by several times but also the critical values responsible for advanced eutrophication. The study showed that the River Giłwa, which flows through the reservoir, posed a major threat to the analysed lake . In order to improve the water quality in Lake Rentyńskie drastic protective measures should be taken in the basin of the River Giłwa, which is intensively used for agriculture, and also, at the point where the river enters the lake a special system to reduce the level of phosphorus compound concentrations should be set up.

  2. Bibliography for acid-rock drainage and selected acid-mine drainage issues related to acid-rock drainage from transportation activities

    Science.gov (United States)

    Bradley, Michael W.; Worland, Scott C.

    2015-01-01

    Acid-rock drainage occurs through the interaction of rainfall on pyrite-bearing formations. When pyrite (FeS2) is exposed to oxygen and water in mine workings or roadcuts, the mineral decomposes and sulfur may react to form sulfuric acid, which often results in environmental problems and potential damage to the transportation infrastructure. The accelerated oxidation of pyrite and other sulfidic minerals generates low pH water with potentially high concentrations of trace metals. Much attention has been given to contamination arising from acid mine drainage, but studies related to acid-rock drainage from road construction are relatively limited. The U.S. Geological Survey, in cooperation with the Tennessee Department of Transportation, is conducting an investigation to evaluate the occurrence and processes controlling acid-rock drainage and contaminant transport from roadcuts in Tennessee. The basic components of acid-rock drainage resulting from transportation activities are described and a bibliography, organized by relevant categories (remediation, geochemical, microbial, biological impact, and secondary mineralization) is presented.

  3. Estimating relations between temperature, relative humidity as independed variables and selected water quality parameters in Lake Manzala, Egypt

    Directory of Open Access Journals (Sweden)

    Gehan A.H. Sallam

    2018-03-01

    Full Text Available In Egypt, Lake Manzala is the largest and the most productive lake of northern coastal lakes. In this study, the continuous measurements data of the Real Time Water Quality Monitoring stations in Lake Manzala were statistically analyzed to measure the regional and seasonal variations of the selected water quality parameters in relation to the change of air temperature and relative humidity. Simple formulas are elaborated using the DataFit software to predict the selected water quality parameters of the Lake including pH, Dissolved Oxygen (DO, Electrical Conductivity (EC, Total Dissolved Solids (TDS, Turbidity, and Chlorophyll as a function of air temperature, relative humidity and quantities and qualities of the drainage water that discharge into the lake. An empirical positive relation was found between air temperature and the relative humidity and pH, EC and TDS and negative relation with DO. There is no significant effect on the other two parameters of turbidity and chlorophyll.

  4. Drainage of radioactive areas

    International Nuclear Information System (INIS)

    1981-04-01

    This Code of Practice covers all the drainage systems which may occur in the radioactive classified area of an establishment, namely surface water, foul, process and radioactive drainage. It also deals with final discharge lines. The Code of Practice concentrates on those aspects of drainage which require particular attention because the systems are in or from radioactive areas and typical illustrations are given in appendices. The Code makes references to sources of information on conventional aspects of drainage design. (author)

  5. Resilience of Socio-Hydrological Systems in Canadian Prairies to Agricultural Drainage: Policy Analysis and Modelling Approach

    Science.gov (United States)

    Wheater, H. S.; Xu, L.; Gober, P.; Pomeroy, J. W.; Wong, J.

    2017-12-01

    Extensive agricultural drainage of lakes and wetlands in the Canadian Prairies has led to benefits for agricultural production, but has had a substantial influence on hydrological regimes and wetland extent. There is need for the potential impacts of current policy in changing the socio-hydrological resilience of prairie wetland basins in response to agricultural drainage to be examined. Whilst wetland drainage can increase agricultural productivity, it can also reduce stocks of natural capital and decrease ecosystem services, such as pollutant retention, habitat for waterfowls, carbon sequestration, and downstream flood attenuation. Effective policies that balance drainage benefits and negative externalities have to consider pricing. This is explored here using the Cold Regions Hydrological Model for hydrological simulations and the Inclusive Wealth approach for modelling in support of cost-benefit analysis. Inclusive wealth aggregates the value of natural, human, and technological assets used to produce social welfare. A shadow price, defined as the marginal change in social value for a marginal change in the current stock quantity, is used to valuate assets that contribute to social welfare. The shadow price of each asset is estimated by taking into account the social and economic benefits and external losses of wetland services caused by wetland drainage. The coupled model was applied to the Smith Creek Research Basin in south-eastern Saskatchewan, Canada where wetland drainage has caused major alterations of the hydrological regime including increased peak flows, discharge volumes and duration of streamflow. Changes in depressional storage in wetlands was used to calculate the corresponding changes of inclusive wealth over a 30-year period under the impacts from the limitation proposed in the Agricultural Water Management Strategy of Saskatchewan. The adjusted societal values of drainage demonstrate the dynamics between changes in hydrological conditions of

  6. A POSSIBLE TSUNAMI IN THE LABRADOR SEA RELATED TO THE DRAINAGE OF GLACIAL LAKE AGASSIZ ~8400 YEARS B.P.

    Directory of Open Access Journals (Sweden)

    N. Nirupama

    2005-01-01

    Full Text Available For thousands of years, the thick Laurentide Ice Sheet covered a large part of northern North America, damming northward-draining rivers. As this ice retreated, large lakes formed along its margin. Glacial Lake Agassiz was the largest of these ice-marginal lakes, covering an area of >800,000 km2 (more than twice the size of the largest lake in the modern world, the Caspian Sea before it drained catastrophically into the Labrador Sea. Even before that, Lake Agassiz had periodically released large volumes of water into the ocean via the Great Lakes-St. Lawrence and the Athabasca-Mackenzie River systems. The last and largest of these outbursts released >150,000 km3 through Hudson Bay and Hudson Strait in 6-12 months; the average flux over that period was ~5 Sv (1 Sv = 1×106 m3s-1.When a volume of water this large is discharged into a coastal sea like the Labrador Sea, it may generate a surface flood wave or a tsunami if the water mass is large enough and introduced in a short time. To our knowledge no previous calculations have been made to estimate the potential impact of a flood burst on the generation of solitary waves. Using analogies of tsunamis generated by submarine landslides and ocean earthquakes, the amplitude of a Lake Agassiz generated tsunami is estimated to have been at least 2 m. Directionality considerations, as well as the effect of the Coriolis Force in the Northern Hemisphere, suggest that the resulting tsunami probably traveled 50-100 km along the west coast of the Labrador Sea, south of Hudson Strait where the outburst entered the ocean, before being dissipated. The erosional and depositional affects of historic and prehistoric tsunamis are present in the geological record, and provide guidance in seeking evidence for the Lake Agassiz flood burst and subsequent tsunami. This record may be found along the western coast of the Labrador Sea as well as along the shores of Hudson Strait.

  7. Are there still roles for exocrine bladder drainage and portal venous drainage for pancreatic allografts?

    Science.gov (United States)

    Young, Carlton J

    2009-02-01

    Controversy remains regarding the best methodology of handling exocrine pancreatic fluid and pancreatic venous effluent. Bladder drainage has given way to enteric drainage. However, is there an instance in which bladder drainage is preferable? Also, hyperinsulinemia, as a result of systemic venous drainage (SVD), is claimed to be proatherosclerotic, whereas portal venous drainage (PVD) is more physiologic and less atherosclerotic. Bladder drainage remains a viable method of exocrine pancreas drainage, but evidence is sparse that measuring urinary amylase has a substantial benefit in the early detection of acute rejection in all types of pancreas transplants. Currently, there is no incontrovertible evidence that systemic hyperinsulinemia is proatherosclerotic, whereas recent metabolic studies on SVD and PVD showed that there was no benefit to PVD. Given the advent of newer immunosuppressive agents and overall lower acute rejection rates, the perceived benefit of bladder drainage as a means to measure urinary amylase as an early marker of rejection has not been substantiated. However, there may be a selective role for bladder drainage in 'high risk' pancreases. Also, without a clear-cut metabolic benefit to PVD over SVD, it remains the surgeon's choice as to which method to use.

  8. Norm Levels in Mine Pit Lakes in South-Western Spain

    International Nuclear Information System (INIS)

    Manjón, G.; Galván, J.; Mantero, J.; Díaz, I.; García-Tenorio, R.

    2015-01-01

    Former mining activities in a pyritic area in south-western Spain have generated mine pits in which underground water and rainwater has accumulated. The accumulated waters have produced oxidation of the pyrite and, consequently, the pit water has become acidic, causing the dissolution of metals and radionuclides of natural origin. The paper discusses the activity concentration levels of uranium isotopes and other radionuclides in water samples and sediments collected from these mine pit lakes. Tributaries of the nearby Odiel River, when crossing the mining area, show low pH values and high concentrations of uranium isotopes due to acid mine drainage. Through the analysis of several isotope activity ratios, the presence of radionuclides in the pit lakes and the influence of these radionuclides on the surrounding area and the Odiel River are evaluated. (author)

  9. Subsurface drainage volume reduction with drainage water management: Case studies in Ohio, USA

    Science.gov (United States)

    One of the main contributors to poor water quality in the Mississippi River and aeral increase in the hypoxic zone in the Gulf of Mexico is intensive drainage of the cropland within the watershed. Controlled drainage has been demonstrated as an approach to curb totla drainage outflow and nutrient di...

  10. Glacial lakes in South Tyrol: distribution, evolution and potential for GLOFs

    Science.gov (United States)

    Schug, Marie-Claire; Mergili, Martin

    2017-04-01

    All over the world glaciers are currently retreating, leading to the formation or growth of glacial lakes. Some of these lakes are susceptible to sudden drainage. In order to assess the danger of glacial lake outburst floods (GLOFs) in South Tyrol in the Italian Alps, we present (i) an inventory of lakes, (ii) an analysis of the development of selected glacial lakes since 1945, and (iii) the susceptibility to and the possible impact areas of GLOFs. The inventory includes 1010 lakes that are larger than 250 m2 at an elevation above 2000 m asl, most of them of glacial origin. These lakes are mapped manually from orthophotos. Apart from collecting information on the spatial distribution of these lakes, the inventory lists dam material, glacier contact, and further parameters. 89% of the lakes in the investigation area are impounded by bedrock, whereas 93% of the lakes are detached from the associated glacier. The majority of lakes is small to medium sized (selected lakes are analyzed in detail in the field and from multi-temporal orthophotos, including the development of lake size and surroundings in the period since 1945. The majority of the selected lakes, however, was first recorded on orthophotos from the early 1980s. Eight of ten lakes grew significantly in that period. But when the lakes detached from the glacier until the early 2000s, the growth slowed down or ceased. Based on the current development of the selected lakes we conclude that the close surroundings of these lakes have stabilised and the lakes' susceptibility to an outburst has thus decreased. We further conduct broad-scale analyses of the susceptibility of the mapped lakes to GLOFs, and of the potential reach of possible GLOFs. The tool r.glachaz is used to determine the potentially dangerous lakes. Even though some few lakes require closer attention, the overall susceptibility to GLOFs in South Tyrol is relatively low, as most lakes are impounded by bedrock. In some cases, GLOFs caused by impact

  11. Tracking Organic Carbon Transport From the Stordalen Mire to Glacial Lake Tornetrask, Abisko, Sweden

    Science.gov (United States)

    Beck, M. A.; Hamilton, B. T.; Spry, E.; Johnson, J. E.; Palace, M. W.; McCalley, C. K.; Varner, R. K.; Bothner, W. A.

    2016-12-01

    In subarctic regions, labile organic carbon from thawing permafrost and productivity of terrestrial and aquatic vegetation are sources of carbon to lake sediments. Methane is produced in lake sediments from the decomposition of organic carbon at rates affected by vegetation presence and type as well as sediment temperature. Recent research in the Stordalen Mire in northern Sweden has suggested that labile organic carbon sources in young, shallow lake sediments yield the highest in situ sediment methane concentrations. Ebullition (or bubbling) of this methane is predominantly controlled by seasonal warming. In this project we sampled stream, glacial and post-glacial lake sediments along a drainage transect through the Stordalen Mire into the large glacial Lake Torneträsk. Our results indicate that the highest methane and total organic carbon (TOC) concentrations were observed in lake and stream sediments in the upper 25 centimeters, consistent with previous studies. C/N ratios range from 8 to 32, and suggest that a mix of aquatic and terrestrial vegetation sources dominate the sedimentary record. Although water transport occurs throughout the mire, major depositional centers for sediments and organic carbon occur within the lakes and prohibit young, labile TOC from entering the larger glacial Lake Torneträsk. The lack of an observed sediment fan at the outlet of the Mire to the lake is consistent with this observation. Our results suggest that carbon produced in the mire stays in the mire, allowing methane production to be greater in the mire bound lakes and streams than in the larger adjacent glacial lake.

  12. Environmental monitoring of Micro Prespa Lake basin (Western Macedonia, Greece): hydrogeochemical characteristics of water resources and quality trends.

    Science.gov (United States)

    Tziritis, Evangelos P

    2014-07-01

    The Micro Prespa basin is a trilateral catchment area of significant importance with a unique ecosystem closely related to the homonymous lake. In this frame, a fully operational monitoring project was carried out including continuous real-time measurements in Micro Prespa Lake with the use of a multi-sensor probe, as well as periodical sampling and analyses of all available water systems for an extended set of 85 parameters. Four main interacting water systems were identified, including alluvial and karstic aquifers, Micro Prespa Lake and adjacent drainage network. The results outlined that general environmental conditions are satisfying in respect to the relative legislation and the hydrogeochemical signatures. However, trends of environmental pressures were ascertained as a result of natural (geogenic) factors, embracing seasonal peaks for Ni, Pb, and NH4 mainly in groundwater systems. Based on chlorophyll a records, Micro Prespa is classified as oligotrophic to slightly mesotrophic, subjected to seasonal variations. Heavy metal concentrations are low, except Ni which appears to have elevated values during the dry hydrological period. Finally, the hydrogeochemistry of drainage network is primarily influenced by surface runoff of the surrounding mountainous areas, hence elevated phosphorus values of the Aghios Germanos stream are possibly linked with the leaching of the granitic formations on the east.

  13. Localized Glacier Deformation Associated with Filling and Draining of a Glacier-Dammed Lake and Implications for Outburst Flood Hydraulics

    Science.gov (United States)

    Cunico, M. L.; Walder, J. S.; Fountain, A. G.; Trabant, D. C.

    2001-12-01

    During the summer of 2000, we measured displacements of 22 survey targets on the surface of Kennicott Glacier, Alaska, in the vicinity of Hidden Creek Lake, an ice-dammed lake in a tributary valley that fills and drains annually. Targets were distributed over a domain about equal in width to the lake, from near the glacier/lake margin to a distance of about 1 km from the margin. Targets were surveyed over a 24-day period as the lake filled and then drained. Lake stage was independently monitored. Vertical movement of targets generally fell off with distance d from the lake. As the lake filled, targets with d typically about 0.5 m/d--with a few targets rising slightly faster than the lake. The rate of vertical movement fell off rapidly with distance from the lake: for d = ca. 600 m--roughly twice the local ice thickness--targets moved upward only about 10% as fast as lake stage. Vertical movement of targets with d > ca. 1 km seemed to be uncorrelated with lake stage. The general pattern is consistent with the idea that a wedge of water extended beneath the glacier to a distance of perhaps 300 to 400 m from the visible margin of the lake and exerts buoyant stresses on the ice that were transmitted into the main body of the glacier and caused flexure. This scenario bears some resemblance to tidal deflections of ice shelves or tidewater glaciers. For a given value of lake stage, target elevations were invariably higher as the lake drained than as the lake filled. Moreover, survey targets at a distance of about 400 m or more from the lake continued to rise for some time even after the lake began to drain. The lag time between the beginning of lake drainage and the beginning of target downdrop increased with distance from the lake, with the lag being about 14 hours at a distance of 400 m from the lake. (The lake drained completely in approximately 75 hours.) The likeliest explanations for the departure from reversibility and the existence of the time lag are either (i) a

  14. Escapement monitoring of adult chinook salmon in the Secesh River and Lake Creek, Idaho, 1999; ANNUAL

    International Nuclear Information System (INIS)

    Faurot, Dave; Kucera, Paul A.

    2001-01-01

    Underwater time-lapse video technology was used to monitor adult spring and summer chinook salmon abundance in spawning areas in Lake Creek and the Secesh River, Idaho, in 1999. This technique is a passive methodology that does not trap or handle this Endangered Species Act listed species. This was the third year of testing the remote application of this methodology in the Secesh River drainage. Secesh River chinook salmon represent a wild salmon spawning aggregate that has not been directly supplemented with hatchery fish. Adult chinook salmon spawner abundance was estimated in Lake Creek with the remote time-lapse video application. Adult spawner escapement into Lake Creek in 1999 was 67 salmon. Significant upstream and downstream spawner movement affected the ability to determine the number of fish that contributed to the spawning population. The first passage on Lake Creek was recorded on July 11, two days after installation of the fish counting station. Peak net upstream adult movement occurred at the Lake Creek site on July 20, peak of total movement activity was August 19 with the last fish observed on August 26. A minimum of 133 adult chinook salmon migrated upstream past the Secesh River fish counting station to spawning areas in the Secesh River drainage. The first upstream migrating adult chinook salmon passed the Secesh River site prior to the July 15 installation of the fish counting station. Peak net upstream adult movement at the Secesh River site occurred July 19, peak of total movement was August 15, 17 and 18 and the last fish passed on September 10. Migrating salmon in the Secesh River and Lake Creek exhibited two behaviorally distinct segments of fish movement. Mainly upstream only, movement characterized the first segment. The second segment consisted of upstream and downstream movement with very little net upstream movement. Estimated abundance was compared to single and multiple-pass redd count surveys within the drainage. There were

  15. Pesticides in the surface waters of Lake Vistonis Basin, Greece: Occurrence and environmental risk assessment.

    Science.gov (United States)

    Papadakis, Emmanouil-Nikolaos; Tsaboula, Aggeliki; Kotopoulou, Athina; Kintzikoglou, Katerina; Vryzas, Zisis; Papadopoulou-Mourkidou, Euphemia

    2015-12-01

    A study was undertaken for the evaluation of the pesticide pollution caused by the agricultural activities in the basin of Lake Vistonis, Greece during the years 2010-2012. Water samples were collected from Lake Vistonis, four major rivers and various small streams and agriculture drainage canals. The concentration of 302 compounds was determined after solid-phase extraction of the water samples and subsequent LC-MS/MS and GC-MS/MS analysis of the extracts. Overall, herbicides were the most frequently detected pesticides (57%), followed by insecticides (28%) and fungicides (14%). In Lake Vistonis 11 pesticides were detected. Specifically, fluometuron was detected in the 75% of the samples (maximum concentration 0.088 μg/L) whereas lambda-cyhalothrin was detected in all the samples of spring 2011 and alphamethrin in all the samples of spring 2012 (maximum concentration 0.041 and 0.168 μg/L, respectively). In the rivers and drainage canals 68 pesticides were detected. Specifically, fluometuron was detected in the 53% of the samples (maximum concentration 317.6 μg/L) followed by chlorpyrifos and prometryn (16 and 13% of the samples respectively). An environmental risk assessment was performed by employing the Risk Quotient (RQ) method. The risk assessment revealed that at least one pesticide concentration led to a RQ>1 in 20% of the samples. In Lake Vistonis, alphamethrin and lambda-cyhalothrin concentrations resulted in RQ>1, whereas in the other water bodies this was mainly the result of chlorpyrifos-methyl and alphamethrin exposure. In contrast, herbicide and fungicide concentrations contributed substantially less to environmental risks. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Drainage water management combined with cover crop enhances reduction of soil phosphorus loss.

    Science.gov (United States)

    Zhang, T Q; Tan, C S; Zheng, Z M; Welacky, T; Wang, Y T

    2017-05-15

    Integrating multiple practices for mitigation of phosphorus (P) loss from soils may enhance the reduction efficiency, but this has not been studied as much as individual ones. A four-year study was conducted to determine the effects of cover crop (CC) (CC vs. no CC, NCC) and drainage water management (DWM) (controlled drainage with sub-irrigation, CDS, vs. regular free tile drainage, RFD) and their interaction on P loss through both surface runoff (SR) and tile drainage (TD) water in a clay loam soil of the Lake Erie region. Cover crop reduced SR flow volume by 32% relative to NCC, regardless of DWM treatment. In contrast, CC increased TD flow volume by 57 and 9.4% with CDS and RFD, respectively, compared to the corresponding DWM treatment with NCC. The total (SR+TD) field water discharge volumes were comparable amongst all the treatments. Cover crop reduced flow-weighted mean (FWM) concentrations of particulate P (PP) by 26% and total P (TP) by 12% in SR, while it didn't affect the FWM dissolved reactive P (DRP) concentration, regardless of DWM treatments. Compared with RFD, CDS reduced FWM DRP concentration in TD water by 19%, while CC reduced FWM PP and TP concentrations in TD by 21 and 17%, respectively. Total (SR+TD) soil TP loss was the least with CDS-CC followed by RFD-CC, CDS-NCC, and RFD-NCC. Compared with RFD-NCC, currently popular practice in the region, total TP loss was reduced by 23% with CDS-CC. The CDS-CC system can be an effective practice to ultimately mitigate soil P loading to water resource. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Supraglacial Lakes in the Percolation Zone of the Western Greenland Ice Sheet: Formation and Development using Operation IceBridge Snow Radar and ATM (2009-2014)

    Science.gov (United States)

    Chen, C.; Howat, I. M.; de la Peña, S.

    2015-12-01

    Surface meltwater lakes on the Greenland Ice Sheet have appeared at higher elevations, extending well into the percolation zone, under recent warming, with the largest expansion occurring in the western Greenland Ice Sheet. The conditions that allow lakes to form atop firn are poorly constrained, but the formation of new lakes imply changes in the permeability of the firn at high elevations, promoting meltwater runoff. We explore the formation and evolution of new surface lakes in this region above 1500 meters, using a combination of satellite imagery and repeat Snow (2-6.5 GHz) radar echograms and LIDAR measurements from NASA's Operation IceBridge of 2009-2014. We identify conditions for surface lake formation at their farthest inland extent and suggest behaviors of persistence and lake drainage are due to differences in regional ice dynamics.

  18. Antifouling herbicides in the coastal waters of western Japan.

    Science.gov (United States)

    Okamura, H; Aoyama, I; Ono, Y; Nishida, T

    2003-01-01

    Residue analyses of some antifouling herbicides (Diuron, Irgarol 1051 and the latter's degradation product M1, which is also known as GS26575), were conducted in waters collected along the coast of western Japan. In total, 142 water samples were collected from fishery harbours (99 sites), marinas (27 sites), and small ports (16 sites) around the Seto Inland Sea, the Kii Peninsula, and Lake Biwa, in August 1999. A urea-based herbicide, Diuron, was positively identified for the first time in Japanese aquatic environments. Diuron was detected in 121 samples (86%) up to a highest concentration of 3.05 microg/l, and was found in 86% of samples from fishery harbours, 89% from marinas, and 75% from ports. Four freshwater samples out of 11 collected at Lake Biwa contained Diuron. Neither Irgarol 1051 nor M1 was found in the lake waters, but both were found in many coastal waters. Irgarol 1051 was found in 84 samples (60%) at a highest concentration of 0.262 microg/l. The concentrations detected were of similar magnitude to those in our previous surveys, taken in 1997 and 1998. M1 was found in 40 samples (28%) up to a highest concentration of 0.080 microg/l. The concentrations detected were generally lower than those found in our previous surveys. The detection frequency among fishery harbours, marinas, and ports was 57-70% for Irgarol 1051 and 25-30% for M1. Ninety-five per cent of the coastal waters in which M1 was detected also contained Irgarol 1051, and 93% of the samples in which Irgarol 1051 was detected also contained Diuron. These results clearly suggest that commercial ship-bottom paints containing both Diuron and Irgarol 1051 are used extensively in the survey area.

  19. Isotopic mass balance of Manzala Lake as indicators of present and past hydrogeological processes in Egypt

    International Nuclear Information System (INIS)

    Salem, M.W.M.

    2006-01-01

    Lakes are very important part of the aquatic ecosystem, which represent about 15% of the total commercial fishing areas in Egypt. Manzala lake is considered one of the largest lakes in Egypt. It is located in the north-eastern edge of the Nile delta and suffering from industrial and agricultural pollutions. The most serious source of pollution may be from Port Said and Damietta wastes, which dumped regularly into the lake. The main object of the present study is to investigate the hydrochemical and isotopic features of the lake waters and to compare the parameters deduced in the present and previous investigations in order to improve the current knowledge of the dynamic change during this time. The stable isotope (oxygen-18) component mass balance approach was used to find out the evaporation rate and the seepage from the groundwater to the lake. The data showed that the seepage rate from the groundwater to the lake was 305.54 x 106 m3/y (about 2% higher than previous study) since the amounts of drainage water became higher. The evaporation rate was 2185.844 x 106 m3/y (about 5% less than previous study). This is due to the reduction in the lake size. Although these rates are relatively small, yet they indicate an alarm for pollution propagation around the lake, which would increase with time

  20. Spatial variations in drainage efficiency in a boreal wetland environment as a function of lidar and radar-derived deviations from the regional hydraulic gradient

    Science.gov (United States)

    Hopkinson, C.; Brisco, B.; Chasmer, L.; Devito, K.; Montgomery, J. S.; Patterson, S.; Petrone, R. M.

    2017-12-01

    The dense forest cover of the Western Boreal Plains of northern Alberta is underlain by a mix of glacial moraines, sandy outwash sediments and clay plains possessing spatially variable hydraulic conductivities. The region is also characterised by a large number of post-glacial surface depression wetlands that have seasonally and topographically limited surface connectivity. Consequently, drainage along shallow regional hydraulic gradients may be dominated either by variations in surface geology or local variations in Et. Long-term government lake level monitoring is sparse in this region, but over a decade of hydrometeorological monitoring has taken place around the Utikuma Regional Study Area (URSA), a research site led by the University of Alberta. In situ lake and ground water level data are here combined with time series of airborne lidar and RadarSat II synthetic aperture radar (SAR) data to assess the spatial variability of water levels during late summer period characterised by flow recession. Long term Lidar data were collected or obtained by the authors in August of 2002, 2008, 2011 and 2016, while seasonal SAR data were captured approximately every 24 days during the summers of 2015, 2016 and 2017. Water levels for wetlands exceeding 100m2 in area across a north-trending 20km x 5km topographic gradient north of Utikuma Lake were extracted directly from the lidar and indirectly from the SAR. The recent seasonal variability in spatial water levels was extracted from SAR, while the lidar data illustrated more long term trends associated with land use and riparian vegetation succession. All water level data collected in August were combined and averaged at multiple scales using a raster focal statistics function to generate a long term spatial map of the regional hydraulic gradient and scale-dependent variations. Areas of indicated high and low drainage efficiency were overlain onto layers of landcover and surface geology to ascertain causal relationships

  1. Microbial Diversity and Its Relationship to Physicochemical Characteristics of the Water in Two Extreme Acidic Pit Lakes from the Iberian Pyrite Belt (SW Spain.

    Directory of Open Access Journals (Sweden)

    Esther Santofimia

    Full Text Available The Iberian Pyrite Belt (IPB hosts one of the world's largest accumulations of acidic mine wastes and pit lakes. The mineralogical and textural characteristics of the IPB ores have favored the oxidation and dissolution of metallic sulfides, mainly pyrite, and the subsequent formation of acidic mining drainages. This work reports the physical properties, hydrogeochemical characteristics, and microbial diversity of two pit lakes located in the IPB. Both pit lakes are acidic and showed high concentrations of sulfate and dissolved metals. Concentrations of sulfate and heavy metals were higher in the Nuestra Señora del Carmen lake (NSC by one order of magnitude than in the Concepción (CN lake. The hydrochemical characteristics of NSC were typical of acid mine waters and can be compared with other acidic environments. When compared to other IPB acidic pit lakes, the superficial water of CN is more diluted than that of any of the others due, probably, to the strong influence of runoff water. Both pit lakes showed chemical and thermal stratification with well defined chemoclines. One particular characteristic of NSC is that it has developed a chemocline very close to the surface (2 m depth. Microbial community composition of the water column was analyzed by 16S and 18S rRNA gene cloning and sequencing. The microorganisms detected in NSC were characteristic of acid mine drainage (AMD, including iron oxidizing bacteria (Leptospirillum, Acidithiobacillus ferrooxidans and facultative iron reducing bacteria and archaea (Acidithiobacillus ferrooxidans, Acidiphilium, Actinobacteria, Acidimicrobiales, Ferroplasma detected in the bottom layer. Diversity in CN was higher than in NSC. Microorganisms known from AMD systems (Acidiphilium, Acidobacteria and Ferrovum and microorganisms never reported from AMD systems were identified. Taking into consideration the hydrochemical characteristics of these pit lakes and the spatial distribution of the identified

  2. In-office drainage of sinus Mucoceles: An alternative to operating-room drainage.

    Science.gov (United States)

    Barrow, Emily M; DelGaudio, John M

    2015-05-01

    Endoscopic drainage has become the standard of care for the treatment of mucoceles. In many patients this can be performed in the office. This study reviews our experience with in-office endoscopic mucocele drainage. Retrospective chart review. A retrospective review of one surgeon's experience with in-office endoscopic drainage of sinus mucoceles between 2006 and 2014 was performed. Charts were reviewed for patient demographics, previous surgery, mucocele location, bone erosion, and outcomes. Thirty-two patients underwent 36 in-office drainage procedures. All procedures were performed under topical/local anesthesia. The mean age was 55 years (range, 17-92 years). The mean follow-up time was 444 days. Fifty-five percent had previous sinus surgery. The primary sinus involved was the frontal (12), anterior (11), posterior ethmoid (six), maxillary (four), and sphenoid (two). Bone erosion was noted to be present on computed tomography in 18 mucoceles (51%) (16 orbital, seven skull-base). All mucoceles were successfully accessed in the office with the exception of one, which was aborted due to neo-osteogenesis. Five patients (14% of mucoceles) required additional surgery, two for mucocele recurrence and three for septated mucoceles not completely drained in the office. No treatment complications occurred. All but one patient preferred in-office to operating-room drainage. In-office drainage of sinus mucoceles is well tolerated by patients, with high success and low complication rates, even in large mucoceles with bone erosion. The presence of septations and neo-osteogenesis reduce the likelihood of complete drainage and are relative contraindications. Orbital and skull base erosion are not contraindications. 4. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  3. Fractionation of cesium isotopes and 90Sr in snowmelt run-off and lake waters from a contaminated Norwegian mountain catchment

    International Nuclear Information System (INIS)

    Salbu, B.; Bjoernstad, H.E.; Brittain, J.E.

    1992-01-01

    Cesium isotopes and 90 Sr have been determined in the inflow and outflow rivers of a Norwegian subalpine lake. The lake is situated in an area contaminated by Chernobyl fallout. Sampling was carried out during the spring peak discharge period associated with snowmelt. Transported coarse particulate plant material was collected by traps. Particles and colloids were removed from water samples by hollow fibre ultrafiltration. The results illustrate that run-off during the spring snowmelt is an important pathway for these radionuclides. The cesium isotopes are predominantly transported as colloids, while 90 Sr is present in the form of low molecular weight mobile species. Based on lake budget calculations, more than 50% of the cesium input is retained in the lake, while more than 90% of the 90 Sr is transported through the lake and into lower parts of the drainage system. (author) 16 refs.; 6 figs.; 3 tabs

  4. Selenium poisoning of fish by coal ash wastewater in Herrington Lake, Kentucky.

    Science.gov (United States)

    Lemly, A Dennis

    2018-04-15

    Selenium pollution from the E.W. Brown Electric Generating Station was investigated in Herrington Lake, KY. Coal ash wastewater is discharged as surface water overflow from ash disposal ponds into the lake via a National Pollutant Discharge Elimination System permit issued by the Kentucky Division of Water, but the permit does not restrict or limit the amount of selenium released. Unpermitted discharges occur from seeps and drainage through leaks in ash pond dams. Together, these discharges have resulted in selenium concentrations in water, sediment, benthic macroinvertebrates, and fish that are 2-9 times the level that is toxic for fish reproduction and survival. A large proportion (12.2%, or 25 times background) of juvenile largemouth bass (Micropterus salmoides, the only species examined) exhibited spinal and/or craniofacial malformations that are consistent with selenium poisoning. Teratogenic Deformity Index values indicated a 3.05% population-level impact on the bass fishery, with total selenium-induced mortality (including pre-swimup mortality) estimated to be in excess of 25% per year. These findings confirm that coal ash discharges into Herrington Lake are contributing selenium to the Lake that is poisoning fish. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Escapement Monitoring of Adult Chinook Salmon in the Secesh River and Lake Creek, Idaho, 1999 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Faurot, Dave; Kucera, Paul A. (Nez Perce Tribe, Lapwai, ID)

    2001-04-01

    Underwater time-lapse video technology was used to monitor adult spring and summer chinook salmon abundance in spawning areas in Lake Creek and the Secesh River, Idaho, in 1999. This technique is a passive methodology that does not trap or handle this Endangered Species Act listed species. This was the third year of testing the remote application of this methodology in the Secesh River drainage. Secesh River chinook salmon represent a wild salmon spawning aggregate that has not been directly supplemented with hatchery fish. Adult chinook salmon spawner abundance was estimated in Lake Creek with the remote time-lapse video application. Adult spawner escapement into Lake Creek in 1999 was 67 salmon. Significant upstream and downstream spawner movement affected the ability to determine the number of fish that contributed to the spawning population. The first passage on Lake Creek was recorded on July 11, two days after installation of the fish counting station. Peak net upstream adult movement occurred at the Lake Creek site on July 20, peak of total movement activity was August 19 with the last fish observed on August 26. A minimum of 133 adult chinook salmon migrated upstream past the Secesh River fish counting station to spawning areas in the Secesh River drainage. The first upstream migrating adult chinook salmon passed the Secesh River site prior to the July 15 installation of the fish counting station. Peak net upstream adult movement at the Secesh River site occurred July 19, peak of total movement was August 15, 17 and 18 and the last fish passed on September 10. Migrating salmon in the Secesh River and Lake Creek exhibited two behaviorally distinct segments of fish movement. Mainly upstream only, movement characterized the first segment. The second segment consisted of upstream and downstream movement with very little net upstream movement. Estimated abundance was compared to single and multiple-pass redd count surveys within the drainage. There were

  6. MERGANSER: an empirical model to predict fish and loon mercury in New England lakes.

    Science.gov (United States)

    Shanley, James B; Moore, Richard; Smith, Richard A; Miller, Eric K; Simcox, Alison; Kamman, Neil; Nacci, Diane; Robinson, Keith; Johnston, John M; Hughes, Melissa M; Johnston, Craig; Evers, David; Williams, Kate; Graham, John; King, Susannah

    2012-04-17

    MERGANSER (MERcury Geo-spatial AssessmeNtS for the New England Region) is an empirical least-squares multiple regression model using mercury (Hg) deposition and readily obtainable lake and watershed features to predict fish (fillet) and common loon (blood) Hg in New England lakes. We modeled lakes larger than 8 ha (4404 lakes), using 3470 fish (12 species) and 253 loon Hg concentrations from 420 lakes. MERGANSER predictor variables included Hg deposition, watershed alkalinity, percent wetlands, percent forest canopy, percent agriculture, drainage area, population density, mean annual air temperature, and watershed slope. The model returns fish or loon Hg for user-entered species and fish length. MERGANSER explained 63% of the variance in fish and loon Hg concentrations. MERGANSER predicted that 32-cm smallmouth bass had a median Hg concentration of 0.53 μg g(-1) (root-mean-square error 0.27 μg g(-1)) and exceeded EPA's recommended fish Hg criterion of 0.3 μg g(-1) in 90% of New England lakes. Common loon had a median Hg concentration of 1.07 μg g(-1) and was in the moderate or higher risk category of >1 μg g(-1) Hg in 58% of New England lakes. MERGANSER can be applied to target fish advisories to specific unmonitored lakes, and for scenario evaluation, such as the effect of changes in Hg deposition, land use, or warmer climate on fish and loon mercury.

  7. Percutaneous drainage of lung abscesses

    International Nuclear Information System (INIS)

    van Sonnenberg, E.; D'Agostino, H.; Casola, G.; Vatney, R.R.; Wittich, G.R.; Harker, C.

    1989-01-01

    The authors performed percutaneous drainage of lung abscesses in 12 patients. Indications for drainage were septicemia and persistence or worsening of radiographic findings. These lung abscesses were refractory to intravenous antibiotics and to bronchial toilet. Etiology of the abscesses included pneumonia (most frequently), trauma, postoperative development, infected necrotic neoplasm, and infected sequestration. Guidelines for drainage included passage of the catheter through contiguously abnormal lung and pleura, inability of the patient to cough, and/or bronchial obstruction precluding bronchial drainage. Cure was achieved in 11 of 12 patients. Catheters were removed on an average of 16 days after insertion. Antibiotics were administered an average of 18 days before drainage. No major complications occurred

  8. Soil phosphorus loss in tile drainage water from long-term conventional- and non-tillage soils of Ontario with and without compost addition.

    Science.gov (United States)

    Zhang, T Q; Tan, C S; Wang, Y T; Ma, B L; Welacky, T

    2017-02-15

    Recent ascertainment of tile drainage a predominant pathway of soil phosphorus (P) loss, along with the rise in concentration of soluble P in the Lake Erie, has led to a need to re-examine the impacts of agricultural practices. A three-year on-farm study was conducted to assess P loss in tile drainage water under long-term conventional- (CT) and non-tillage (NT) as influenced by yard waste leaf compost (LC) application in a Brookston clay loam soil. The effects of LC addition on soil P loss in tile drainage water varied depending on P forms and tillage systems. Under CT, dissolved reactive P (DRP) loss with LC addition over the study period was 765g P ha -1 , 2.9 times higher than CT without LC application, due to both a 50% increase in tile drainage flow volume and a 165% increase in DRP concentration. Under NT, DRP loss in tile drainage water with LC addition was 1447gPha -1 , 5.3 times greater than that for NT without LC application; this was solely caused by a 564% increase in DRP concentration. However, particulate P loads in tile drainage water with LC application remained unchanged, relative to non-LC application, regardless of tillage systems. Consequently, LC addition led to an increase in total P loads in tile drainage water by 57 and 69% under CT and NT, respectively. The results indicate that LC application may become an environmental concern due to increased DRP loss, particularly under NT. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  9. Monitoring and optimization of thermal recovery wells at Nexen's Long Lake project

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, S.; Howe, A.; Wozney, G.; Zaffar, S. [Nexen Inc. (Canada); Nelson, A. [Matrikon Inc. (Canada)

    2011-07-01

    The Long Lake project, operated by Nexen and situated in the Athabasca Oil Sands area in Alberta, Canada is a steam assisted gravity drainage scheme. In such thermal recovery processes, access to real time information is crucial. Nexen used specific tools to optimize monitoring in its Long Lake project and the aim of this paper is to present those customized well and facilities dashboards and reservoir trends. Real time and historical data on pressure, temperature injection and production rates are used in a Honeywell PHD Historian connected to a Delta-V DCS system to optimize recovery from the deposit. Results showed that these enhanced monitoring capabilities provided Nexen the ability to react rapidly to abnormal conditions, which resulted in significant financial benefits. The implementation of dashboard and reservoir trends in its Long Lake project helped Nexen to better monitor the reservoir and thus to optimize bitumen recovery.

  10. Water balance along a chain of tundra lakes: A 20-year isotopic perspective

    Science.gov (United States)

    Gibson, J. J.; Reid, R.

    2014-11-01

    Stable isotope measurements and isotope mass balance (IMB) calculations are presented in support of an unprecedented 20-year water balance assessment for a tailings pond and a chain of downstream lakes at the Salmita-Tundra mine site, situated near Courageous Lake, Northwest Territories, Canada (65°03‧N; 111°11‧W). The method is shown to provide a comprehensive annual and interannual perspective of water balance fluxes along a chain of lakes during the period 1991-2010, without the need for continuous streamflow gauging, and reveals important lake-order-dependent patterns of land-surface runoff, discharge accumulation, and several key diagnostic ratios, i.e., evaporation/inflow, evaporation/evapotranspiration, land-surface-runoff/precipitation and discharge/ precipitation. Lake evaporation is found to be a significant component of the water balance, accounting for between 26% and 32% of inflow to natural lakes and between 72% and 100% of inflow to mine-tailings ponds. Evaporation/evapotranspiration averages between 7% and 22% and is found to be higher in low-precipitation years, and in watersheds with a higher proportion of lakes. Runoff ratios for land-surface drainages and runoff ratios for watersheds (including lakes) ranged between 14-47% and 20-47%, respectively, and were higher in low precipitation years, in watersheds with a higher proportion of lakes, and in watersheds less affected by mining development. We propose that in general these two runoff ratios will likely converge as lake order increases and as land cover conditions become regionally representative. Notably, the study demonstrates application of IMB, validated with streamflow measurements, to constrain local water balance in a remote low-arctic region. For IMB chain-of-lakes applications, it underlines the importance of accounting for evaporatively-enriched upstream sources to avoid overestimation of evaporation losses.

  11. Percutaneous catheter drainage of lung abscess

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Shin; Chun, Kyung Ah; Choi, Hyo Sun; Ha, Hyun Kown; Shinn, Kyung Sub [Catholic University Medical college, Seoul (Korea, Republic of)

    1993-09-15

    From March 1987 to July 1989, six patients (five adults and one child) with lung abscess (size, 5-13 cm in diameter) were treated with percutaneous aspiration and drainage. In each case, the puncture was made where the wall of the abscess was in contact with the pleural surface. An 8 to 10 Fr cartheter was inserted for drainage. Five of 6 had a dynamatic clinical response within 24 hours of the drainage. Percutaneous drainage was successful with complete abscess resolution in four and partial resolution in one patient. No response was seen in the rest one. The duration of drainage ranged from 7 to 18 days(average, 15.5 days) in successful cases. One case of the failure in drainage was due tio persistent aspiration of the neurologically impaired patient. In one patient, the abscess resolved after drainage but recurred after inadvertent removal of the catheter 7 days after insertion. In two patients, concurrent pleural empyema was resolved completely by the drainage. Computed tomography provide anatomic details necessary for choosing the puncture site and avoiding a puncture of the lung parenchyma. Percutaneous catheter drainage is safe and effective method for treating patient with lung abscess.

  12. Percutaneous catheter drainage of lung abscess

    International Nuclear Information System (INIS)

    Kim, Young Shin; Chun, Kyung Ah; Choi, Hyo Sun; Ha, Hyun Kown; Shinn, Kyung Sub

    1993-01-01

    From March 1987 to July 1989, six patients (five adults and one child) with lung abscess (size, 5-13 cm in diameter) were treated with percutaneous aspiration and drainage. In each case, the puncture was made where the wall of the abscess was in contact with the pleural surface. An 8 to 10 Fr cartheter was inserted for drainage. Five of 6 had a dynamatic clinical response within 24 hours of the drainage. Percutaneous drainage was successful with complete abscess resolution in four and partial resolution in one patient. No response was seen in the rest one. The duration of drainage ranged from 7 to 18 days(average, 15.5 days) in successful cases. One case of the failure in drainage was due tio persistent aspiration of the neurologically impaired patient. In one patient, the abscess resolved after drainage but recurred after inadvertent removal of the catheter 7 days after insertion. In two patients, concurrent pleural empyema was resolved completely by the drainage. Computed tomography provide anatomic details necessary for choosing the puncture site and avoiding a puncture of the lung parenchyma. Percutaneous catheter drainage is safe and effective method for treating patient with lung abscess

  13. Dryness of ephemeral lakes and consequences for dust activity: the case of the Hamoun drainage basin, southeastern Iran.

    Science.gov (United States)

    Rashki, A; Kaskaoutis, D G; Goudie, A S; Kahn, R A

    2013-10-01

    This study examines the influence of changes in the water coverage in the Hamoun dry-bed lakes on visibility, dust outbreaks, aerosol loading and land-atmospheric fluxes over the region covering the period 1985-2005. The Hamoun basin, located on the southeastern Iran and western Afghanistan borders, has been recognized as one of the major dust source regions in south Asia and is covered by shallow, marshy lakes that are fed by the Helmand and Farahrood rivers. When the water in watersheds that support the lakes is drawn down for natural or human-induced reasons, the end result is a decrease in the water coverage in the basin, or even complete dryness as occurred in 2001. Then, strong seasonal winds, mainly in summer, blow fine sand and silt off the exposed lakebed, enhancing dust activity and aerosol loading over the region. Satellite (Landsat) and meteorological observations reveal that the water levels in the Hamoun lakes exhibit considerable inter-annual variability during the period 1985-2005 strongly related to anomalies in precipitation. This is the trigger for concurrent changes in the frequency of the dusty days, aerosol loading and deterioration of visibility over the region, as satellite (TOMS, MODIS, MISR) observations reveal. On the other hand, soil moisture and latent heat, obtained via model (GLDAS_noah-10) simulations are directly linked with water levels and precipitation over the region. The desiccation of the Hamoun lakes in certain years and the consequent increase in frequency and intensity of dust storms are serious concerns for the regional climate, ecosystems and human health. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. The 24 July 2008 outburst flood at the western Zyndan glacier lake and recent regional changes in glacier lakes of the Teskey Ala-Too range, Tien Shan, Kyrgyzstan

    Directory of Open Access Journals (Sweden)

    C. Narama

    2010-04-01

    Full Text Available On 24 July 2008, a glacier lake outburst flood (GLOF occurred at the western (w- Zyndan glacier lake in the Tong District of Ysyk-Köl Oblast, Kyrgyzstan. The flood killed three people and numerous livestock, destroyed infrastructure, and devastated potato and barley crops as well as pastures. Tuurasuu village and a downstream reservoir on the Zyndan river escaped heavy damage because the main flood was diverted toward the Tong river. RTK-GPS and satellite data (Landsat 7 ETM+, ALOS/PRISM, and ALOS/AVNIR-2 reveal that the flood reduced the lake area from 0.0422 km2 to 0.0083 km2, discharging 437 000 m3 of water. This glacier lake was not present in a Landsat 7 ETM+ image taken on 26 April 2008. It formed rapidly over just two and half months from early May to the late July, when large amounts of snow and glacier melt water became trapped in a basin in the glacier terminus area, blocked by temporary closure of the drainage channel through the terminal moraine that included much dead-ice. In the same mountain region, most other glacier-lake expansions were not particularly large during the period from 1999–2008. Although events like the w-Zyndan glacier lake outburst occur infrequently in the high Central Asian mountains, such fast developing, short-lived lakes are particularly dangerous and not easy to monitor using satellite data. Appropriate measures to protect against such lake outburst hazards in this region include educating residents on glacier hazards and monitoring techniques, providing frequently updated maps of glacier lakes, and planning and monitoring land-use, including house locations.

  15. An open source high-performance solution to extract surface water drainage networks from diverse terrain conditions

    Science.gov (United States)

    Stanislawski, Larry V.; Survila, Kornelijus; Wendel, Jeffrey; Liu, Yan; Buttenfield, Barbara P.

    2018-01-01

    This paper describes a workflow for automating the extraction of elevation-derived stream lines using open source tools with parallel computing support and testing the effectiveness of procedures in various terrain conditions within the conterminous United States. Drainage networks are extracted from the US Geological Survey 1/3 arc-second 3D Elevation Program elevation data having a nominal cell size of 10 m. This research demonstrates the utility of open source tools with parallel computing support for extracting connected drainage network patterns and handling depressions in 30 subbasins distributed across humid, dry, and transitional climate regions and in terrain conditions exhibiting a range of slopes. Special attention is given to low-slope terrain, where network connectivity is preserved by generating synthetic stream channels through lake and waterbody polygons. Conflation analysis compares the extracted streams with a 1:24,000-scale National Hydrography Dataset flowline network and shows that similarities are greatest for second- and higher-order tributaries.

  16. Mid-to-Late Holocene Hydrologic Variability in the Southeastern Mojave Desert Using Sediments from Ford Lake

    Science.gov (United States)

    Mayer, S. A.; Kirby, M. E.; Anderson, W. T., Jr.; Stout, C.; Palermo, J. A.

    2015-12-01

    The focal point of most lacustrine studies in the Mojave National Preserve (MNP) to date has been on lakes fed by the Mojave River. The source of the Mojave River is found on the northern flank of the San Bernardino Mountains. Consequently, the lakes that receive these waters are predominantly responding to the winter-only coastal southwest United States climate (e.g., Kirby et al., 2015 - Silver Lake); to a lesser degree, these lakes are also influenced by the Mojave's bimodal winter/summer climate. Ford Lake, located in the southeastern Mojave Desert is a small closed basin lake with its drainage basin located exclusively within the Mojave Desert. Therefore, sediment collected from Ford Lake contains a 100% Mojave-only climate signal. A 2.18 m sediment core was collected from the lake's depocenter in May 2015. Sediment analyses at 1 cm contiguous intervals include: magnetic susceptibility (MS), percent total organic matter, percent total carbonate content, and grain size analysis; C:N ratios, C and N isotope (δ13C and δ15N) analyses, and macrofossil counts are determined at 2 cm intervals. The site's age model is based on accelerator mass spectrometry (AMS) radiocarbon ages from discrete organic macrofossils or bulk organic carbon. To deconvolve the coastal climate, winter-only signal from the Mojave-only climate signal the data from Ford Lake will be compared to one Mojave River fed lake (Silver) and several southern California lakes (Lower Bear, Lake Elsinore, Dry Lake, and Zaca Lake). Our results will be analyzed in the context of climate forcings such as insolation and ocean - atmosphere dynamics.

  17. Water and sediment quality of the Lake Andes and Choteau Creek basins, South Dakota, 1983-2000

    Science.gov (United States)

    Sando, Steven Kent; Neitzert, Kathleen M.

    2003-01-01

    The Bureau of Reclamation has proposed construction of the Lake Andes/Wagner Irrigation Demonstration Project to investigate environmental effects of irrigation of glacial till soils substantially derived from marine shales. During 1983-2000, the U.S. Geological Survey collected hydrologic, water-quality, and sediment data in the Lake Andes and Choteau Creek Basins, and on the Missouri River upstream and downstream from Choteau Creek, to provide baseline information in support of the proposed demonstration project. Lake Andes has a drainage area of about 230 mi2 (square miles). Tributaries to Lake Andes are ephemeral. Water-level fluctuations in Lake Andes can be large, and the lake has been completely dry on several occasions. The outlet aqueduct from Lake Andes feeds into Garden Creek, which enters Lake Francis Case just upstream from Fort Randall Dam on the Missouri River. For Lake Andes tributary stations, calcium, magnesium, and sodium are approximately codominant among the cations, and sulfate is the dominant anion. Dissolved-solids concentrations typically range from about 1,000 mg/L (milligrams per liter) to about 1,700 mg/L. Major-ion concentrations for Lake Andes tend to be higher than the tributaries and generally increase downstream in Lake Andes. Proportions of major ions are similar among the different lake units (with the exception of Owens Bay), with calcium, magnesium, and sodium being approximately codominant among cations, and sulfate being the dominant anion. Owens Bay is characterized by a calcium sulfate water type. Dissolved-solids concentrations for Lake Andes typically range from about 1,400 to 2,000 mg/L. Whole-water nitrogen and phosphorus concentrations are similar among the Lake Andes tributaries, with median whole-water nitrogen concentrations ranging from about 1.6 to 2.4 mg/L, and median whole-water phosphorus concentrations ranging from about 0.5 to 0.7 mg/L. Whole-water nitrogen concentrations in Lake Andes are similar among the

  18. Routine Sub-hepatic Drainage versus No Drainage after Laparoscopic Cholecystectomy: Open, Randomized, Clinical Trial.

    Science.gov (United States)

    Shamim, Muhammad

    2013-02-01

    Surgeons are still following the old habit of routine subhepatic drainage following laparoscopic cholecystectomy (LC). This study aims to compare the outcome of subhepatic drainage with no drainage after LC. This prospective study was conducted in two phases. Phase I was open, randomized controlled trial (RCT), conducted in Civil Hospital Karachi, from August 2004 to June 2005. Phase II was descriptive case series, conducted in author's practice hospitals of Karachi, from July 2005 to December 2009. In phase I, 170 patients with chronic calculous cholecystitis underwent LC. Patients were divided into two groups, subhepatic drainage (group A: 79 patients) or no drainage (group B: 76 patients). The rest 15 patients were excluded either due to conversion or elective subhepatic drainage. In phase II, 218 consecutive patients were enrolled, who underwent LC with no subhepatic drainage. Duration of operation, character, and amount of drain fluid (if placed), postoperative ultrasound for subhepatic collection, postoperative chest X-ray for the measurement of subdiaphragmatic air, postoperative pain, postoperative nausea/vomiting, duration of hospital stay, and preoperative or postoperative complications were noted and analyzed. Duration of operation and hospital stay was slightly longer in group A patients (P values 0.002 and 0.029, respectively); postoperative pain perception, nausea/vomiting, and postoperative complications were nearly same in both groups (P value 0.064, 0.078, and 0.003, respectively). Subhepatic fluid collection was more in group A (P = 0.002), whereas subdiaphragmatic air collection was more in group B (P = 0.003). Phase II results were nearly similar to group B patients in phase I. Routine subhepatic drainage after LC is not necessary in uncomplicated cases.

  19. Floristic Diversity of Lakes Subjected to Long Term Changes in the Water Network of the West Polesie (Eastern Poland

    Directory of Open Access Journals (Sweden)

    Sender Joanna

    2017-07-01

    Full Text Available The Wieprz-Krzna Canal, built in 1961, is one of the longest in Poland (142 km. Although the drainage construction was intended to revitalize the region of wetlands and peat-bogs of the West Polesie, it caused large hydrological changes. Research on catchments of three natural lakes and three retention reservoirs involved cartographic analysis using photointerpretation, as well as the Braun-Blanquet method. In the studied area, between 1939 and 2016 the length of rivers and ditches increased more than three times. Macrophytes covered about 20-27% of the natural lakes water surface, whereas in retention reservoirs the coverage was 12-15.5%. Also a greater diversity of macrophytes occurred in natural lakes. In retention reservoirs it was restricted to only emerged macrophytes.

  20. Planning Of Drainage Channel Dimension In The Core Zone Of Muara Takus Temple

    Science.gov (United States)

    Saleh, Alfian

    2017-12-01

    Preservation of Cultural Heritage is a dynamic effort to maintain the existence of cultural heritage by protecting, developing, and utilizing the cultural heritage in the contemporary context. To protect the cultural heritage in term of conservation called protection of which the effort to prevent and overcome from damage, it needs to do destruction or obliteration through rescue, security, zoning, maintenance, and restoration of cultural heritage. The most fundamental issue is the hydrological impact of the existence of Hydroelectric Power Koto Panjang located around Muara Takus temple that could threaten the sustainability of the region. In this case, hydroelectric dam frequently causes Kampar Kanan River overflowed thus potentially floods, especially in the rainy season that could eventually submerges Muara Takus area. The total area of the region Muara Takus enshrinement is ± 94.5 hectares that are divided into two main parts. Those are the terrestrial land of ± 56.44 m², and PLTA Koto Panjang lake of ± 38.06 m². Consequently, it is necessary for drainage planning of economical dimension in the core zone of Muara Takus temple. Furthermore, from the data of the maximum rainfall of 101 mm/day obtained a discharge of rainfall of 0.38 m3/second so that this discharge of rainfall can be designed drainage channel dimension to accommodate the discharge of rainfall. From the analysis of dimension designed drainage is the size of 30 cm x 45 cm. this dimension can accommodate the discharge rainfall that is equal to 0.43 m3 / second. Regarding the finding, it can be concluded that the discharge of rainfall that occurred less than discharge calculation of dimensional analysis of drainage channel so that the size of this dimension can accommodate discharge rainfall occurs.

  1. Oh Magadi! Interpreting isoGDGTs and n-alkanes in a saline tropical lake: Lake Magadi, Kenya

    Science.gov (United States)

    Ferland, T. M.; Werne, J. P.; Castañeda, I. S.; Cohen, A. S.; Lowenstein, T. K.; Deocampo, D.; Renaut, R.; Bernhart, O. R.

    2017-12-01

    The Hominin Sites and Paleolakes Drilling Project (HSPDP) seeks to understand the paleoclimatic and paleoenvironmental context of hominin adaptation and evolution by analysis of paleolacustrine cores taken near key hominin fossil and artifact localities in Kenya and Ethiopia. We present biomarker and compound specific isotope data from a 200 m drill core from Lake Magadi, Kenya. Located 20 km from the Koora Plain in the southern Kenya Rift, and adjacent to the Olorgesailie basin, Lake Magadi is in one of the richest Early-Late Pleistocene archaeological localities in Africa, a region that has been key in debates about the relationship between climate and evolution. Present-day Lake Magadi is a saline pan, a descendant of a series of paleolakes that have occupied its drainage basin and progressively dried for approximately one million years. Nearly 70% of samples analyzed for n-alkanes recorded a robust terrestrial signal. The majority of samples did not contain the complete suite of branched GDGTs necessary to reconstruct temperature from the Methylation of Branched Tetraethers and Cyclisation of Branched Tetraethers (MBT/CBT; Weijers et al., 2007) proxy. The TetraEther indeX with 86 carbon atoms (TEX86; Schouten et al., 2002) temperature proxy was established for 90% of samples analyzed for isoGDGTs, however the Methane and Ring Indices (Zhang et al., 2011; Zhang et al., 2016) suggest that the TEX86 is not applicable to temperature reconstruction at Magadi. Despite this, the Magadi TEX86 temperature reconstruction appears to agree with not only the trends in our n-alkane data but with other regional and global records, including the GRIP-2 δ18O record. We compare our temperature data to other records in the region, and investigate influences on our TEX86 data including microbial community turnover and lake drying.

  2. Meltwater drainage beneath ice sheets: What can we learn from uniting observations of paleo- and contemporary subglacial hydrology?

    Science.gov (United States)

    Simkins, L. M.; Carter, S. P.; Greenwood, S. L.; Schroeder, D. M.

    2017-12-01

    Understanding meltwater at the base of ice sheets is critical for predicting ice flow and subglacial sediment deformation. Whereas much progress has been made with observing contemporary systems, these efforts have been limited by the short temporal scales of remote sensing data, the restricted spatial coverage of radar sounding data, and the logistical challenges of direct access. Geophysical and sedimentological data from deglaciated continental shelves reveal broad spatial and temporal perspectives of subglacial hydrology, that complement observations of contemporary systems. Massive bedrock channels, such as those on the sediment-scoured inner continental shelf of the Amundsen Sea and the western Antarctic Peninsula, are up to hundreds of meters deep, which indicate either catastrophic drainage events or slower channel incision over numerous glaciations or sub-bank full drainage events. The presence of these deep channels has implications for further ice loss as they may provide conduits today for warm water incursion into sub-ice shelf cavities. Sediment-based subglacial channels, widespread in the northern hemisphere terrestrial domain and increasingly detected on both Arctic and Antarctic marine margins, help characterize more ephemeral drainage systems active during ice sheet retreat. Importantly, some observed sediment-based channels are connected to upstream subglacial lakes and terminate at paleo-grounding lines. From these records of paleo-subglacial hydrology, we extract the relative timing of meltwater drainage, estimate water fluxes, and contemplate the sources and ultimate fate of basal meltwater, refining predictive models for modern systems. These insights provided by geological data fill a gap in knowledge regarding spatial and temporal dynamics of subglacial hydrology and offer hindsight into meltwater drainage influence/association with ice flow and retreat behavior. The union of information gathered from paleo- and contemporary subglacial

  3. Endoscopic Ultrasound-Guided Perirectal Abscess Drainage without Drainage Catheter: A Case Series

    Directory of Open Access Journals (Sweden)

    Eun Kwang Choi

    2017-05-01

    Full Text Available A perirectal abscess is a relatively common disease entity that occurs as a postsurgical complication or as a result of various medical conditions. Endoscopic ultrasound (EUS-guided drainage was recently described as a promising alternative treatment. Previous reports have recommended placement of a drainage catheter through the anus for irrigation, which is inconvenient to the patient and carries a risk of accidental dislodgement. We report four cases of perirectal abscess that were successfully treated with only one or two 7 F double pigtail plastic stent placements and without a drainage catheter for irrigation.

  4. Exploring Agricultural Drainage's Influence on Wetland and ...

    Science.gov (United States)

    Artificial agricultural drainage (i.e. surface ditches or subsurface tile) is an important agricultural management tool. Artificial drainage allows for timely fieldwork and adequate root aeration, resulting in greater crop yields for farmers. This practice is widespread throughout many regions of the United States and the network of artificial drainage is especially extensive in flat, poorly-drained regions like the glaciated Midwest. While beneficial for crop yields, agricultural drains often empty into streams within the natural drainage system. The increased network connectivity may lead to greater contributing area for watersheds, altered hydrology and increased conveyance of pollutants into natural water bodies. While studies and models at broader scales have implicated artificial drainage as an important driver of hydrological shifts and eutrophication, the actual spatial extent of artificial drainage is poorly known. Consequently, metrics of wetland and watershed connectivity within agricultural regions often fail to explicitly include artificial drainage. We use recent agricultural census data, soil drainage data, and land cover data to create estimates of potential agricultural drainage across the United States. We estimate that agricultural drainage in the US is greater than 31 million hectares and is concentrated in the upper Midwest Corn Belt, covering greater than 50% of available land for 114 counties. Estimated drainage values for numerous countie

  5. Holocene surge-history of the Eyjabakkajökull glacier inferred from varved lake sediments on eastern Iceland

    Science.gov (United States)

    Striberger, J.; Bjorck, S.; Ingolfsson, O.; Kjaer, K.; Snowball, I.; Uvo, C. B.

    2009-12-01

    Properties of varved lake sediments from Lake Lögurinn on eastern Iceland and their link to glacial processes of Eyjabakkajökull, a surging outlet glacier of the Vatnajökull ice cap, is examined. An 18 m long sediment sequence obtained from the lake, covering at least the past ~ 9 200 years, displays a distinct recurring pattern of light-coloured clay dominated laminae sections. The thickness of the light-coloured laminae is mainly controlled by the amount of glacial rock flour transported from Eyjabakkajökull. These light laminae are interlaid by coarser dark-coloured laminae mainly formed by suspended matter transported to the lake by the large non-glacial river Grímsá. During the recent surge of Eyjabakkajökull in 1972, the amount of suspended matter transported to the lake increased significantly. The surge was followed by years of recurring drainages of Lake Háöldulón, an ice-dammed lake that was formed shortly after the surge. As a result, the amount of glacial rock flour transported to Lake Lögurinn was higher than usual as long as Lake Háöldulón continued to drain (i.e. as long as the ice front was in an advanced position enough to dam the lake). This increase in glacially derived rock flour is reflected in the sediments, as the varve that was formed in 1972 constitutes the thickest light-coloured laminae deposited during the 20th century, which is followed by the second thickest light-coloured laminae, deposited in 1973. From there on, the thicknesses of the light-coloured laminae gradually fade out. Based on these modern observations, we suggest that the recurring cyclic pattern of light-coloured clay dominated laminae sections in the sediment sequence is related to past surges of Eyjabakkajökull, followed by drainages of Lake Háöldulón. Recurring cycles of light-coloured clay dominated laminae began to develop close to the Hekla-3 and Hekla-4 tephras (ca. 3000-4000 years BP), which also coincides with the time when the varves became

  6. Post-glacial, land rise-induced formation and development of lakes in the Forsmark area, central Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Brunberg, Anna-Kristina; Blomqvist, Peter [Uppsala Univ. (Sweden). Dept. of Limnology, Evolutionary Biology Centre

    2000-03-15

    This report describes the lakes of Uppsala county, with special emphasis on the coastal lakes in the Forsmark area. The aim of the study is to characterise different main types of lakes within the Forsmark area and to create a basis for prediction of their ontogeny, that can be used also for new lakes which due to shoreline displacement will be formed during the next 10 000 years. Areas where future research is needed to fully understand the functioning of the lake ecosystems and their ontogeny have also been identified. Three main types of lake ecosystems could be identified: The oligotrophic hardwater lakes are to a large extent surrounded by mires. Inflow as well as outflow of water is often diffuse, via the surrounding mire. The lakes are small and shallow, with nutrient poor and highly alkaline water. Three key habitats have been identified within the lakes; i) the pelagic zone, characterised by low production of biota, ii) the presumably moderately productive emergent macrophyte zone, dominated by Sphagnum and Phragmites, and iii) the light-exposed soft-bottom zone with Chara meadows and an unusually rich and presumably highly productive microbial sediment community. In later stages of the lake ontogeny, Sphagnum becomes more and more dominant in the system, which successively turns acidic. The final stage is likely to be a raised bog ecosystem with an autonomous hydrological functioning. The brown water lakes are typically found within the main part of the River Forsmarksaan and are characterised by a high flow-through of water from the upper parts of the drainage area, which are dominated by mires. Their lake water is highly stained by allochtonous organic carbon imported from the catchment area. Also in this lake type a Sphagnum-littoral successively develops, and in a mature lake three key habitats can be identified; i) the pelagic zone, most likely the dominant habitat in terms of production of organisms and in which bacterioplankton dominates the

  7. Post-glacial, land rise-induced formation and development of lakes in the Forsmark area, central Sweden

    International Nuclear Information System (INIS)

    Brunberg, Anna-Kristina; Blomqvist, Peter

    2000-03-01

    This report describes the lakes of Uppsala county, with special emphasis on the coastal lakes in the Forsmark area. The aim of the study is to characterise different main types of lakes within the Forsmark area and to create a basis for prediction of their ontogeny, that can be used also for new lakes which due to shoreline displacement will be formed during the next 10 000 years. Areas where future research is needed to fully understand the functioning of the lake ecosystems and their ontogeny have also been identified. Three main types of lake ecosystems could be identified: The oligotrophic hardwater lakes are to a large extent surrounded by mires. Inflow as well as outflow of water is often diffuse, via the surrounding mire. The lakes are small and shallow, with nutrient poor and highly alkaline water. Three key habitats have been identified within the lakes; i) the pelagic zone, characterised by low production of biota, ii) the presumably moderately productive emergent macrophyte zone, dominated by Sphagnum and Phragmites, and iii) the light-exposed soft-bottom zone with Chara meadows and an unusually rich and presumably highly productive microbial sediment community. In later stages of the lake ontogeny, Sphagnum becomes more and more dominant in the system, which successively turns acidic. The final stage is likely to be a raised bog ecosystem with an autonomous hydrological functioning. The brown water lakes are typically found within the main part of the River Forsmarksaan and are characterised by a high flow-through of water from the upper parts of the drainage area, which are dominated by mires. Their lake water is highly stained by allochtonous organic carbon imported from the catchment area. Also in this lake type a Sphagnum-littoral successively develops, and in a mature lake three key habitats can be identified; i) the pelagic zone, most likely the dominant habitat in terms of production of organisms and in which bacterioplankton dominates the

  8. A synthesis of thermokarst lake water balance in high-latitude regions of North America from isotope tracers

    Science.gov (United States)

    MacDonald, Lauren A.; Wolfe, Brent B.; Turner, Kevin W.; Anderson, Lesleigh; Arp, Christopher D.; Birks, Jean; Bouchard, Frédéric; Edwards, Thomas W.D.; Farquharson, Nicole; Hall, Roland I.; McDonald, Ian; Narancic, Biljana; Ouimet, Chantal; Pienitz, Reinhard; Tondu, Jana; White, Hilary

    2017-01-01

    Numerous studies utilizing remote sensing imagery and other methods have documented that thermokarst lakes are undergoing varied hydrological transitions in response to recent climate changes, from surface area expansion to drainage and evaporative desiccation. Here, we provide a synthesis of hydrological conditions for 376 lakes of mainly thermokarst origin across high-latitude North America. We assemble surface water isotope compositions measured during the past decade at five lake-rich landscapes including Arctic Coastal Plain (Alaska), Yukon Flats (Alaska), Old Crow Flats (Yukon), northwestern Hudson Bay Lowlands (Manitoba), and Nunavik (Quebec). These landscapes represent the broad range of thermokarst environments by spanning gradients in meteorological, permafrost, and vegetation conditions. An isotope framework was established based on flux-weighted long-term averages of meteorological conditions for each lake to quantify water balance metrics. The isotope composition of source water and evaporation-to-inflow ratio for each lake were determined, and the results demonstrated a substantial array of regional and subregional diversity of lake hydrological conditions. Controls on lake water balance and how these vary among the five landscapes and with differing environmental drivers are assessed. Findings reveal that lakes in the Hudson Bay Lowlands are most vulnerable to evaporative desiccation, whereas those in Nunavik are most resilient. However, we also identify the complexity in predicting hydrological responses of these thermokarst landscapes to future climate change.

  9. Mine Drainage Generation and Control Options.

    Science.gov (United States)

    Wei, Xinchao; Rodak, Carolyn M; Zhang, Shicheng; Han, Yuexin; Wolfe, F Andrew

    2016-10-01

    This review provides a snapshot of papers published in 2015 relevant to the topic of mine drainage generation and control options. The review is broken into 3 sections: Generation, Prediction and Prevention, and Treatment Options. The first section, mine drainage generation, focuses on the characterization of mine drainage and the environmental impacts. As such, it is broken into three subsections focused on microbiological characterization, physiochemical characterization, and environmental impacts. The second section of the review is divided into two subsections focused on either the prediction or prevention of acid mine drainage. The final section focuses on treatment options for mine drainage and waste sludge. The third section contains subsections on passive treatment, biological treatment, physiochemical treatment, and a new subsection on beneficial uses for mine drainage and treatment wastes.

  10. Exploring the Recovery Lakes region and interior Dronning Maud Land, East Antarctica, with airborne gravity, magnetic and radar measurements

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Ferraccioli, Fausto

    2017-01-01

    for major Dronning Maud Land ice stream systems, from the grounding lines up to the Recovery Lakes drainage basin, and filled in major data voids in Antarctic data compilations, such as AntGP for gravity data, ADMAP for magnetic data and BEDMAP2 for ice thickness data and the sub-ice topography. We present...

  11. Percutaneous catheter drainage of intrapulmonary fluid collection

    International Nuclear Information System (INIS)

    Park, E. D.; Kim, H. J.; Choi, P. Y.; Jung, S. H.

    1994-01-01

    With the success of percutaneous abdominal abscess drainage, attention is now being focused on the use of similar techniques in the thorax. We studied to evaluate the effect of percutaneous drainage in parenchymal fluid collections in the lungs. We performed percutaneous drainage of abscesses and other parenchymal fluid collections of the lungs in 15 patients. All of the procedures were performed under the fluoroscopic guidance with an 18-gauge Seldinger needle and coaxial technique with a 8-10F drainage catheter. Among 10 patients with lung abscess, 8 patients improved by percutaneous catheter drainage. In one patient, drainage was failed by the accidental withdrawal of the catheter before complete drainage. One patient died of sepsis 5 hours after the procedure. Among three patients with complicated bulla, successful drainage was done in two patients, but in the remaining patient, the procedure was failed. In one patient with intrapulmonary bronchogenic cyst, the drainage was not successful due to the thick internal contents. In one patient with traumatic hematoma, after the drainage of old blood clots, the signs of infection disappeared. Overally, of 14 patients excluding one who died, 11 patients improved with percutaneous catheter drainage and three patients did not. There were no major complications during and after the procedure. We conclude that percutaneous catheter drainage is effective and safe procedure for the treatment of parenchymal fluid collections of the lung in patients unresponsive to the medical treatment

  12. Percutaneous catheter drainage of intrapulmonary fluid collection

    Energy Technology Data Exchange (ETDEWEB)

    Park, E. D.; Kim, H. J.; Choi, P. Y.; Jung, S. H. [Gyeongsang National University Hospital, Chinju (Korea, Republic of)

    1994-01-15

    With the success of percutaneous abdominal abscess drainage, attention is now being focused on the use of similar techniques in the thorax. We studied to evaluate the effect of percutaneous drainage in parenchymal fluid collections in the lungs. We performed percutaneous drainage of abscesses and other parenchymal fluid collections of the lungs in 15 patients. All of the procedures were performed under the fluoroscopic guidance with an 18-gauge Seldinger needle and coaxial technique with a 8-10F drainage catheter. Among 10 patients with lung abscess, 8 patients improved by percutaneous catheter drainage. In one patient, drainage was failed by the accidental withdrawal of the catheter before complete drainage. One patient died of sepsis 5 hours after the procedure. Among three patients with complicated bulla, successful drainage was done in two patients, but in the remaining patient, the procedure was failed. In one patient with intrapulmonary bronchogenic cyst, the drainage was not successful due to the thick internal contents. In one patient with traumatic hematoma, after the drainage of old blood clots, the signs of infection disappeared. Overally, of 14 patients excluding one who died, 11 patients improved with percutaneous catheter drainage and three patients did not. There were no major complications during and after the procedure. We conclude that percutaneous catheter drainage is effective and safe procedure for the treatment of parenchymal fluid collections of the lung in patients unresponsive to the medical treatment.

  13. A computationally efficient depression-filling algorithm for digital elevation models, applied to proglacial lake drainage

    NARCIS (Netherlands)

    Berends, Constantijn J.; Van De Wal, Roderik S W

    2016-01-01

    Many processes govern the deglaciation of ice sheets. One of the processes that is usually ignored is the calving of ice in lakes that temporarily surround the ice sheet. In order to capture this process a "flood-fill algorithm" is needed. Here we present and evaluate several optimizations to a

  14. Comparison of natural drainage group and negative drainage groups after total thyroidectomy: prospective randomized controlled study.

    Science.gov (United States)

    Woo, Seung Hoon; Kim, Jin Pyeong; Park, Jung Je; Shim, Hyun Seok; Lee, Sang Ha; Lee, Ho Joong; Won, Seong Jun; Son, Hee Young; Kim, Rock Bum; Son, Young-Ik

    2013-01-01

    The aim of this study was to compare a negative pressure drain with a natural drain in order to determine whether a negative pressure drainage tube causes an increase in the drainage volume. Sixty-two patients who underwent total thyroidectomy for papillary thyroid carcinoma (PTC) were enrolled in the study between March 2010 and August 2010 at Gyeongsang National University Hospital. The patients were prospectively and randomly assigned to two groups, a negative pressure drainage group (n=32) and natural drainage group (n=30). Every 3 hours, the volume of drainage was checked in the two groups until the tube was removed. The amount of drainage during the first 24 hours postoperatively was 41.68 ± 3.93 mL in the negative drain group and 25.3 ± 2.68 mL in the natural drain group (pdrain group was 35.19 ± 4.26 mL and natural drain groups 21.53 ± 2.90 mL (pdrain may increase the amount of drainage during the first 24-48 hours postoperatively. Therefore, it is not necessary to place a closed suction drain when only a total thyroidectomy is done.

  15. Drainage filter technologies to mitigate site-specific phosphorus losses in agricultural drainage discharge

    DEFF Research Database (Denmark)

    Kjærgaard, Charlotte; Heckrath, Goswin Johann; Canga, Eriona

    in drainage. The Danish “SUPREME-TECH” project (2010-2016) (www.supreme-tech.dk) aims at providing the scientific basis for developing cost-effective filter technologies for P in agricultural drainage waters. The project studies different approaches of implementing filter technologies including drainage well....... Targeting high risk areas of P loss and applying site-specific measures promises to be a cost-efficient approach. The Danish Commission for Nature and Agriculture has, therefore, now called for a paradigm shift towards targeted, cost-efficient technologies to mitigate site-specific nutrient losses...... environmental threshold values (

  16. Late Quaternary sedimentary features of Bear Lake, Utah and Idaho

    Science.gov (United States)

    Smoot, J.P.

    2009-01-01

    Bear Lake sediments were predominantly aragonite for most of the Holocene, reflecting a hydrologically closed lake fed by groundwater and small streams. During the late Pleistocene, the Bear River flowed into Bear Lake and the lake waters spilled back into the Bear River drainage. At that time, sediment deposition was dominated by siliciclastic sediment and calcite. Lake-level fluctuation during the Holocene and late Pleistocene produced three types of aragonite deposits in the central lake area that are differentiated primarily by grain size, sorting, and diatom assemblage. Lake-margin deposits during this period consisted of sandy deposits including well-developed shoreface deposits on margins adjacent to relatively steep gradient lake floors and thin, graded shell gravel on margins adjacent to very low gradient lake-floor areas. Throughout the period of aragonite deposition, episodic drops in lake level resulted in erosion of shallow-water deposits, which were redeposited into the deeper lake. These sediment-focusing episodes are recognized by mixing of different mineralogies and crystal habits and mixing of a range of diatom fauna into poorly sorted mud layers. Lake-level drops are also indicated by erosional gaps in the shallow-water records and the occurrence of shoreline deposits in areas now covered by as much as 30 m of water. Calcite precipitation occurred for a short interval of time during the Holocene in response to an influx of Bear River water ca. 8 ka. The Pleistocene sedimentary record of Bear Lake until ca. 18 ka is dominated by siliciclastic glacial fl our derived from glaciers in the Uinta Mountains. The Bear Lake deep-water siliciclastic deposits are thoroughly bioturbated, whereas shallow-water deposits transitional to deltas in the northern part of the basin are upward-coarsening sequences of laminated mud, silt, and sand. A major drop in lake level occurred ca. 18 ka, resulting in subaerial exposure of the lake floor in areas now covered by

  17. Hydrology of modern and late Holocene lakes, Death Valley, California

    International Nuclear Information System (INIS)

    Grasso, D.N.

    1996-01-01

    Above-normal precipitation and surface-water runoff, which have been generally related to the cyclic recurrence of the El Nino-Southern Oscillation, have produced modern ephemeral lakes in the closed-basin Death Valley watershed. This study evaluates the regional hydroclimatic relations between precipitation, runoff, and lake transgressions in the Death Valley watershed. Recorded precipitation, runoff, and spring discharge data for the region are used in conjunction with a closed-basin, lake-water-budget equation to assess the relative contributions of water from these sources to modern lakes in Death Valley and to identify the requisite hydroclimatic changes for a late Holocene perennial lake in the valley. As part of the Yucca Mountain Site Characterization Program, an evaluation of the Quaternary regional paleoflood hydrology of the potential nuclear-waste repository site at Yucca Mountain, Nevada, was planned. The objectives of the evaluation were (1) to identify the locations and investigate the hydraulic characteristics of paleofloods and compare these with the locations and characteristics of modern floods, and (2) to evaluate the character and severity of past floods and debris flows to ascertain the potential future hazards to the potential repository during the pre-closure period (US Department of Energy, 1988). This study addresses the first of these objectives, and the second in part, by assessing and comparing the sizes, locations, and recurrence rates of modern, recorded (1962--83) floods and late Holocene paleofloods for the 8,533-mi 2 , closed-basin, Death Valley watershed with its contributing drainage basins in the Yucca Mountain site area

  18. Hydrology of modern and late Holocene lakes, Death Valley, California

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, D.N.

    1996-07-01

    Above-normal precipitation and surface-water runoff, which have been generally related to the cyclic recurrence of the El Nino-Southern Oscillation, have produced modern ephemeral lakes in the closed-basin Death Valley watershed. This study evaluates the regional hydroclimatic relations between precipitation, runoff, and lake transgressions in the Death Valley watershed. Recorded precipitation, runoff, and spring discharge data for the region are used in conjunction with a closed-basin, lake-water-budget equation to assess the relative contributions of water from these sources to modern lakes in Death Valley and to identify the requisite hydroclimatic changes for a late Holocene perennial lake in the valley. As part of the Yucca Mountain Site Characterization Program, an evaluation of the Quaternary regional paleoflood hydrology of the potential nuclear-waste repository site at Yucca Mountain, Nevada, was planned. The objectives of the evaluation were (1) to identify the locations and investigate the hydraulic characteristics of paleofloods and compare these with the locations and characteristics of modern floods, and (2) to evaluate the character and severity of past floods and debris flows to ascertain the potential future hazards to the potential repository during the pre-closure period (US Department of Energy, 1988). This study addresses the first of these objectives, and the second in part, by assessing and comparing the sizes, locations, and recurrence rates of modern, recorded (1962--83) floods and late Holocene paleofloods for the 8,533-mi{sup 2}, closed-basin, Death Valley watershed with its contributing drainage basins in the Yucca Mountain site area.

  19. Carbonate deposition, Pyramid Lake subbasin, Nevada: 3. The use of87Sr values in carbonate deposits (tufas) to determine the hydrologic state of paleolake systems

    Science.gov (United States)

    Benson, L.; Peterman, Z.

    1996-01-01

    Sierran rivers that discharge to the Lahontan basin have much lower (???4.5%o) ??87Sr values than the Humboldt River which drains northeastern Nevada. The ??87Sr values of tufas deposited during the last lake cycle were used to determine when Humboldt derived Sr entered the Pyramid Lake subbasin. Prior to ~ 15,000 yr B.P., the Humboldt River flowed to the Smoke Creek-Black Rock Desert subbasin. During the recession of Lake Lahontan, the Humboldt River diverted to the Carson Desert subbasin. This study has demonstrated that 87Sr can be used to determine drainage histories of multi-basin lake systems if the ??87Sr values of rivers that discharge to the basins are sufficiently different. ?? 1995 Elsevier Science B.V. All rights reserved.

  20. Geochemical evolution of groundwater in the Mud Lake area, eastern Idaho, USA

    Science.gov (United States)

    Rattray, Gordon W.

    2015-01-01

    Groundwater with elevated dissolved-solids concentrations—containing large concentrations of chloride, sodium, sulfate, and calcium—is present in the Mud Lake area of Eastern Idaho. The source of these solutes is unknown; however, an understanding of the geochemical sources and processes controlling their presence in groundwater in the Mud Lake area is needed to better understand the geochemical sources and processes controlling the water quality of groundwater at the Idaho National Laboratory. The geochemical sources and processes controlling the water quality of groundwater in the Mud Lake area were determined by investigating the geology, hydrology, land use, and groundwater geochemistry in the Mud Lake area, proposing sources for solutes, and testing the proposed sources through geochemical modeling with PHREEQC. Modeling indicated that sources of water to the eastern Snake River Plain aquifer were groundwater from the Beaverhead Mountains and the Camas Creek drainage basin; surface water from Medicine Lodge and Camas Creeks, Mud Lake, and irrigation water; and upward flow of geothermal water from beneath the aquifer. Mixing of groundwater with surface water or other groundwater occurred throughout the aquifer. Carbonate reactions, silicate weathering, and dissolution of evaporite minerals and fertilizer explain most of the changes in chemistry in the aquifer. Redox reactions, cation exchange, and evaporation were locally important. The source of large concentrations of chloride, sodium, sulfate, and calcium was evaporite deposits in the unsaturated zone associated with Pleistocene Lake Terreton. Large amounts of chloride, sodium, sulfate, and calcium are added to groundwater from irrigation water infiltrating through lake bed sediments containing evaporite deposits and the resultant dissolution of gypsum, halite, sylvite, and bischofite.

  1. [Ascites drainage at home

    NARCIS (Netherlands)

    Lutjeboer, J.; Erkel, A.R. van; Hoeven, J.J.M. van der; Meer, R.W. van der

    2015-01-01

    Ascites can lead to many symptoms, and often occurs in patients with an end-stage malignancy such as ovarian, pancreatic, colonic, or gastric cancer. Intermittent ascites drainage is applied in these patients as a palliative measure. As frequent drainage is necessary, a subcutaneously tunnelled

  2. The greatest soda-water lake in the world and how it is influenced by climatic change

    Directory of Open Access Journals (Sweden)

    M. Kadioğlu

    1997-11-01

    Full Text Available Global warming resulting from increasing greenhouse gases in the atmosphere and the local climate changes that follow affect local hydrospheric and biospheric environments. These include lakes that serve surrounding populations as a fresh water resource or provide regional navigation. Although there may well be steady water-quality alterations in the lakes with time, many of these are very much climate-change dependent. During cool and wet periods, there may be water-level rises that may cause economic losses to agriculture and human activities along the lake shores. Such rises become nuisances especially in the case of shoreline settlements and low-lying agricultural land. Lake Van, in eastern Turkey currently faces such problems due to water-level rises. The lake is unique for at least two reasons. First, it is a closed basin with no natural or artificial outlet and second, its waters contain high concentrations of soda which prevent the use of its water as a drinking or agricultural water source. Consequently, the water level fluctuations are entirely dependent on the natural variability of the hydrological cycle and any climatic change affects the drainage basin. In the past, the lake-level fluctuations appear to have been rather systematic and unrepresentable by mathematical equations. Herein, monthly polygonal climate diagrams are constructed to show the relation between lake level and some meteorological variables, as indications of significant and possible climatic changes. This procedure is applied to Lake Van, eastern Turkey, and relevant interpretations are presented.

  3. Migration of global radioactive fallout to the Arctic Ocean (on the example of the Ob's river drainage basin).

    Science.gov (United States)

    Miroshnikov, A; Semenkov, I

    2012-11-01

    This article provides an assessment of the impact of global fallout on (137)Cs contamination in the bottom sediments of Kara Sea. The erosiveness of 10th-level river basins was estimated by landscape-geochemical and geomorphological characteristics. All 10th-level basins (n=154) were separated into three groups: mountain, mountain-lowland and plain. Four different types of basins were identified depending on the geochemical conditions of the migration of radiocaesium in the plain and mountain-lowland. Classifications of types were carried out using the geographic information systems-based approach. The Ob River's macroarena covers 3.5 million km(2). Internal drainage basins cover 23 % of the macroarena and accumulate whole radiocaesium from the global fallout. The remaining territory is transitional for the (137)Cs. The field research works performed in the three plain first-level basins allow one to estimate the radiocaesium run-off. The calculations show that 7 % of (137)Cs was removed from the first-level basin in arable land. Accumulation of radiocaesium in the first-level basin under undisturbed forest is 99.8 %. The research shows that (137)Cs transfer from the humid basins is in the range of 6.9-25.5 TBq and for semi-humid basins 5.6-285.5 TBq. The areas of these basins cover 40 and 8 % of the Ob River's macroarena, respectively. Drainage lakes and reservoir drainage basins make up 22 % of the macroarena. Mountainous and semi-arid drainage basins cover 7 % of the macroarena.

  4. Percutaneous transhepatic biliary drainage

    International Nuclear Information System (INIS)

    Park, Jae Hyung; Hong, Seong Mo; Han, Man Chung

    1982-01-01

    Percutaneous transhepatic biliary drainage was successfully made 20 times on 17 patients of obstructive jaundice for recent 1 year since June 1981 at Department of Radiology in Seoul National University Hospital. The causes of obstructive jaundice was CBD Ca in 13 cases, metastasis in 2 cases, pancreatic cancer in 1 case and CBD stone in 1 case. Percutaneous transhepatic biliary drainage is a relatively ease, safe and effective method which can be done after PTC by radiologist. It is expected that percutaneous transhepatic biliary drainage should be done as an essential procedure for transient permanent palliation of obstructive jaundice

  5. Surficial geologic map of the Red Rock Lakes area, southwest Montana

    Science.gov (United States)

    Pierce, Kenneth L.; Chesley-Preston, Tara L.; Sojda, Richard L.

    2014-01-01

    The Centennial Valley and Centennial Range continue to be formed by ongoing displacement on the Centennial fault. The dominant fault movement is downward, creating space in the valley for lakes and the deposition of sediment. The Centennial Valley originally drained to the northeast through a canyon now represented by a chain of lakes starting with Elk Lake. Subsequently, large landslides blocked and dammed the drainage, which created Lake Centennial, in the Centennial Valley. Sediments deposited in this late Pleistocene lake underlie much of the valley floor and rest on permeable sand and gravel deposited when the valley drained to the northeast. Cold Pleistocene climates enhanced colluvial supply of gravelly sediment to mountain streams and high peak flows carried gravelly sediment into the valley. There, the lower gradient of the streams resulted in deposition of alluvial fans peripheral to Lake Centennial as the lake lowered through time to the level of the two present lakes. Pleistocene glaciers formed in the high Centennial Range, built glacial moraines, and also supplied glacial outwash to the alluvial fans. Winds from the west and south blew sand to the northeast side of the valley building up high dunes. The central part of the map area is flat, sloping to the west by only 0.6 meters in 13 kilometers (2 feet in 8 miles) to form a watery lowland. This lowland contains Upper and Lower Red Rock Lakes, many ponds, and peat lands inside the “water plane,” above which are somewhat steeper slopes. The permeable sands and gravels beneath Lake Centennial sediments provide a path for groundwater recharged from the adjacent uplands. This groundwater leaks upward through Lake Centennial sediments and sustains wetland vegetation into late summer. Upper and Lower Red Rock Lakes are formed by alluvial-fan dams. Alluvial fans converge from both the south and the north to form outlet thresholds that dam the two shallow lakes upstream. The surficial geology aids in

  6. Characteristics and causal factors of hysteresis in the hydrodynamics of a large floodplain system: Poyang Lake (China)

    Science.gov (United States)

    Zhang, X. L.; Zhang, Q.; Werner, A. D.; Tan, Z. Q.

    2017-10-01

    A previous modeling study of the lake-floodplain system of Poyang Lake (China) revealed complex hysteretic relationships between stage, storage volume and surface area. However, only hypothetical causal factors were presented, and the reasons for the occurrence of both clockwise and counterclockwise hysteretic functions were unclear. The current study aims to address this by exploring further Poyang Lake's hysteretic behavior, including consideration of stage-flow relationships. Remotely sensed imagery is used to validate the water surface areas produced by hydrodynamic modeling. Stage-area relationships obtained using the two methods are in strong agreement. The new results reveal a three-phase hydrological regime in stage-flow relationships, which assists in developing improved physical interpretation of hysteretic stage-area relationships for the lake-floodplain system. For stage-area relationships, clockwise hysteresis is the result of classic floodplain hysteretic processes (e.g., restricted drainage of the floodplain during recession), whereas counterclockwise hysteresis derives from the river hysteresis effect (i.e., caused by backwater effects). The river hysteresis effect is enhanced by the time lag between the peaks of catchment inflow and Yangtze discharge (i.e., the so-called Yangtze River blocking effect). The time lag also leads to clockwise hysteresis in the relationship between Yangtze River discharge and lake stage. Thus, factors leading to hysteresis in other rivers, lakes and floodplains act in combination within Poyang Lake to create spatial variability in hydrological hysteresis. These effects dominate at different times, in different parts of the lake, and during different phases of the lake's water level fluctuations, creating the unique hysteretic hydrological behavior of Poyang Lake.

  7. Estimates of deep drainage rates at the U.S. Department of Energy Pantex Plant, Amarillo, Texas

    International Nuclear Information System (INIS)

    Fayer, M.J.; Richmond, M.C.; Wigmosta, M.S.; Kelley, M.E.

    1998-04-01

    In FY 1996, the Pacific Northwest National Laboratory (PNNL) provided technical assistance to Battelle Columbus Operations (BCO) in their ongoing assessment of contaminant migration at the Pantex Plant in Amarillo, Texas. The objective of this report is to calculate deep drainage rates at the Pantex Plant. These deep drainage rates may eventually be used to predict contaminant loading to the underlying unconfined aquifer for the Pantex Plant Baseline Risk Assessment. These rates will also be used to support analyses of remedial activities involving surface alterations or the subsurface injection withdrawal of liquids or gases. The scope of this report is to estimate deep drainage rates for the major surface features at the Pantex Plant, including ditches and playas, natural grassland, dryland crop rotation, unvegetated soil, and graveled surfaces. Areas such as Pantex Lake that are outside the main plant boundaries were not included in the analysis. All estimates were derived using existing data or best estimates; no new data were collected. The modeling framework used to estimate the rates is described to enable future correlations, improvements, and enhancements. The scope of this report includes only data gathered during FY 1996. However, a current review of the data gathered on weather, soil, plants, and other information in the time period since did not reveal anything that would significantly alter the results presented in this report

  8. Agricultural drainage water quality

    International Nuclear Information System (INIS)

    Madani, A.; Gordon, R.

    2002-01-01

    'Full text:' Agricultural drainage systems have been identified as potential contributors of non-point source pollution. Two of the major concerns have been with nitrate-nitrogen (NO3 - -N) concentrations and bacteria levels exceeding the Maximum Acceptable Concentration in drainage water. Heightened public awareness of environmental issues has led to greater pressure to maintain the environmental quality of water systems. In an ongoing field study, three experiment sites, each with own soil properties and characteristics, are divided into drainage plots and being monitored for NO3 - -N and fecal coliforms contamination. The first site is being used to determine the impact of the rate of manure application on subsurface drainage water quality. The second site is being used to determine the difference between hog manure and inorganic fertilizer in relation to fecal coliforms and NO3-N leaching losses under a carrot rotation system. The third site examines the effect of timing of manure application on water quality, and is the only site equipped with a surface drainage system, as well as a subsurface drainage system. Each of the drains from these fields lead to heated outflow buildings to allow for year-round measurements of flow rates and water samples. Tipping buckets wired to data-loggers record the outflow from each outlet pipe on an hourly basis. Water samples, collected from the flowing drains, are analyzed for NO3 - -N concentrations using the colorimetric method, and fecal coliforms using the Most Probable Number (MPN) method. Based on this information, we will be able better positioned to assess agricultural impacts on water resources which will help towards the development on industry accepted farming practices. (author)

  9. How Might Draining Lake Campotosto Affect Stress and Seismicity on the Monte Gorzano Normal Fault, Central Italy?

    Science.gov (United States)

    Verdecchia, A.; Deng, K.; Harrington, R. M.; Liu, Y.

    2017-12-01

    It is broadly accepted that large variations of water level in reservoirs may affect the stress state on nearby faults. While most studies consider the relationship between lake impoundment and the occurrence of large earthquakes or seismicity rate increases in the surrounding region, very few examples focus on the effects of lake drainage. The second largest reservoir in Europe, Lake Campotosto, is located on the hanging wall of the Monte Gorzano fault, an active normal fault responsible for at least two M ≥ 6 earthquakes in historical times. The northern part of this fault ruptured during the August 24, 2016, Mw 6.0 Amatrice earthquake, increasing the probability for a future large event on the southern section where an aftershock sequence is still ongoing. The proximity of the Campotosto reservoir to the active fault aroused general concern with respect to the stability of the three dams bounding the reservoir if the southern part of the Monte Gorzano fault produces a moderate earthquake. Local officials have proposed draining the reservoir as hazard mitigation strategy to avoid possible future catastrophes. In efforts to assess how draining the reservoir might affect earthquake nucleation on the fault, we use a finite-element poroelastic model to calculate the evolution of stress and pore pressure in terms of Coulomb stress changes that would be induced on the Monte Gorzano fault by emptying the Lake Campotosto reservoir. Preliminary results show that an instantaneous drainage of the lake will produce positive Coulomb stress changes, mostly on the shallower part of the fault (0 to 2 km), while a stress drop of the order of 0.2 bar is expected on the Monte Gorzano fault between 0 and 8 km depth. Earthquake hypocenters on the southern portion of the fault currently nucleate between 5 and 13 km depth, with activity distributed nearby the reservoir. Upcoming work will model the effects of varying fault geometry and elastic parameters, including geological

  10. Rock glaciers in crystalline catchments: Hidden permafrost-related threats to alpine headwater lakes.

    Science.gov (United States)

    Ilyashuk, Boris P; Ilyashuk, Elena A; Psenner, Roland; Tessadri, Richard; Koinig, Karin A

    2018-04-01

    A global warming-induced transition from glacial to periglacial processes has been identified in mountainous regions around the world. Degrading permafrost in pristine periglacial environments can produce acid rock drainage (ARD) and cause severe ecological damage in areas underlain by sulfide-bearing bedrock. Limnological and paleolimnological approaches were used to assess and compare ARDs generated by rock glaciers, a typical landform of the mountain permafrost domain, and their effects on alpine headwater lakes with similar morphometric features and underlying bedrock geology, but characterized by different intensities of frost action in their catchments during the year. We argue that ARD and its effects on lakes are more severe in the alpine periglacial belt with mean annual air temperatures (MAAT) between -2°C and +3°C, where groundwater persists in the liquid phase for most of the year, in contrast to ARD in the periglacial belt where frost action dominates (MAAT cycle of aquatic organisms should be considered when reconstructing long-term trends in the ecotoxicological state of lakes. © 2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  11. LIMNOLOGY, LAKE BASINS, LAKE WATERS

    Directory of Open Access Journals (Sweden)

    Petre GÂŞTESCU

    2009-06-01

    Full Text Available Limnology is a border discipline between geography, hydrology and biology, and is also closely connected with other sciences, from it borrows research methods. Physical limnology (the geography of lakes, studies lake biotopes, and biological limnology (the biology of lakes, studies lake biocoenoses. The father of limnology is the Swiss scientist F.A. Forel, the author of a three-volume entitled Le Leman: monographie limnologique (1892-1904, which focuses on the geology physics, chemistry and biology of lakes. He was also author of the first textbook of limnology, Handbuch der Seenkunde: allgemeine Limnologie,(1901. Since both the lake biotope and its biohydrocoenosis make up a single whole, the lake and lakes, respectively, represent the most typical systems in nature. They could be called limnosystems (lacustrine ecosystems, a microcosm in itself, as the American biologist St.A. Forbes put it (1887.

  12. Arterial Pulsations cannot Drive Intramural Periarterial Drainage: Significance for Aβ Drainage

    Directory of Open Access Journals (Sweden)

    Alexandra K. Diem

    2017-08-01

    Full Text Available Alzheimer's Disease (AD is the most common form of dementia and to date there is no cure or efficient prophylaxis. The cognitive decline correlates with the accumulation of amyloid-β (Aβ in the walls of capillaries and arteries. Our group has demonstrated that interstitial fluid and Aβ are eliminated from the brain along the basement membranes of capillaries and arteries, the intramural periarterial drainage (IPAD pathway. With advancing age and arteriosclerosis, the stiffness of arterial walls, this pathway fails in its function and Aβ accumulates in the walls of arteries. In this study we tested the hypothesis that arterial pulsations drive IPAD and that a valve mechanism ensures the net drainage in a direction opposite to that of the blood flow. This hypothesis was tested using a mathematical model of the drainage mechanism. We demonstrate firstly that arterial pulsations are not strong enough to produce drainage velocities comparable to experimental observations. Secondly, we demonstrate that a valve mechanism such as directional permeability of the IPAD pathway is necessary to achieve a net reverse flow. The mathematical simulation results are confirmed by assessing the pattern of IPAD in mice using pulse modulators, showing no significant alteration of IPAD. Our results indicate that forces other than the cardiac pulsations are responsible for efficient IPAD.

  13. Drainage under increasing and changing requirements

    NARCIS (Netherlands)

    Schultz, E.; Zimmer, D.; Vlotman, W.F.

    2007-01-01

    This year the Working Group on Drainage of the International Commission on Irrigation and Drainage (ICID) celebrates its 25th anniversary. This paper reviews the development of drainage for three different agro-climatic zones, i.e. the temperate (humid), the arid/semi-arid and the humid/semi-humid

  14. Physical and Chemical Characteristics of Lake Edku Water, Egypt

    Directory of Open Access Journals (Sweden)

    M.A. OKBAH

    2002-12-01

    Full Text Available The objective of this work is to evaluate the quality of Lake Edku water. Regional and seasonal variations of some physico-chemical parameters (nutrient salts, total nitrogen, total phosphorous and silicate, in addition to pH, total alkalinity, chlorosity, dissolved oxygen, biological oxygen demand and oxidizable organic matter that were determined during the period from January to December 2000. Important variations have occurred in the investigated area as a result of human activity and the discharge of wastewater to the lake. The relatively low pH values reflect the decreased productivity of the Lake as a result of the polluted water discharged into the lake. Total alkalinity varied between 2.25 ± 0.35 to 8.38 ± 0.9 meq/l. In comparison with previous decades chlorosity content (586-1562 mg/l showed the general decreasing trend. Dissolved oxygen varied (2.37 ± 0.72 - 4.47 ± 0.94 mg/l. The ratios of BOD/ OOM values indicate that the lake water has a biodegradable nature. There was a noticeable variation in ammonia levels; a lower ammonia content was recorded in summer and spring. Nitrite and nitrate concentrations in Lake Edku water showed values ranging from 3.7±1.4 to 7.8±1.9 ΜM and from 15.2±2.9 to 45.9±11.8 ΜM, respectively. The total nitrogen of the lake exhibited higher levels (53.1±12.2 – 164.2±30.7 ΜM. The ratio of NH4/TIN (0.09-0.45 seems to be highly representative of the microbial nitrification rate as well as of the varying agricultural inflows. It is interesting to note that increasing values of reactive phosphate (11.6±1.8 – 14.7±2.5 ΜM were determined in autumn and winter respectively. The higher concentrations of reactive silicate were directly proportional to drainage water discharged into the Lake. It is clear from the mean ratio of N/P (2.4-8.8 nitrogen is the limiting factor. The lower values of N/P ratio could be related to an allochthonous condition.

  15. Contrasting evolution patterns between glacier-fed and non-glacier-fed lakes in the central Tibetan Plateau and driving force analysis

    Science.gov (United States)

    Song, C.; Sheng, Y.

    2015-12-01

    High-altitude lakes in the Tibetan Plateau (TP) showed strong spatio-temporal variability during past decades. The lake dynamics can be associated with several key factors including lake type, supply of glacial meltwater, local climate variations. It is important to differentiate these factors when analyzing the driving force of lakes dynamics. With a focus on lakes over the Tanggula Mountains of the central TP, this study investigates the temporal evolution patterns of lake area and water level of different types: glacier-fed closed lake, non-glacier-fed closed lake and upstream lake (draining into closed lakes). We collected all available Landsat archive data and quantified the inter-annual variability of lake extents. Results show accelerated expansions of both glacier-fed and non-glacier-fed lakes during 1970s-2013, and different temporal patterns of the two types of lakes: the non-glacier-fed lakes displayed a batch-wise growth pattern, with obvious growth in 2002, 2005 and 2011 and slight changes in other years, while glacier-fed lakes showed steady expanding tendency. The contrasting patterns are confirmed by the distinction of lake level change between the two groups derived from satellite altimetry during 2003-2009. The upstream lakes remained largely stable due to natural drainage regulation. The intermittent expansions for non-glacier-fed lakes were found to be related to excessive precipitation events and positive "precipitation-evaporation". In contrast, glacier-fed lake changes showed weak correlations with precipitation variations, which imply a joint contribution from glacial meltwater to water budgets. A simple estimation reveals that the increased water storage for all of examined lakes contributed from precipitation/evaporation (0.31±0.09 Gt/yr) slightly overweighed the glacial meltwater supply (0.26±0.08 Gt/yr).

  16. Social impact assessment of subsurface drainage

    International Nuclear Information System (INIS)

    Azhar, A.H.; Rafiq, M.; Alam, M.M.

    2005-01-01

    Social impact assessment of four drainage projects namely; Mardan SCARP Project (MSP), Fourth Drainage Project, Faisalabad (FDP), Chashma Command Area Development Project (CCADP) and Mirpurkhas Tile Drainage Project (MKOP) has been done. For this purpose, a socio-technical survey was carried out in which randomly selected farmers were interviewed. The investigations revealed that although significant population (-77%) at four study sites was educated, yet, the farmers were not satisfactorily educated to understand the operation and maintenance of drainage systems. The perusal of data revealed that 14%, 17% and 25% respondents from MSP, FOP and MKDP respectively had to migrate from their villages mainly due to pre-project water logging problem. However, installation of drainage systems in those areas improved the situation resulting in the increase of farm income, which was an attraction for them to return to their villages. The analysis of farm mechanization revealed that at MSP, FDP, CCADP and MKOP sites 71%, 42%, 40% and 75% respondents respectively were tractor owners and owners of some kind of other farm implements, whereas, remaining respondents were performing their farm operations on hire basis. Although, hire operation basis is much better than traditional ways, however, improving the farm mechanization could further enhance the benefits of drainage systems. The investigations revealed that a significant majority of respondents at four project sites had never met the Agricultural Extension Officer. The farmers' access to financing institutions such as ZTB was also negligible. There was lack of coordination among various departments such as WAPDA, Agriculture Extension and Irrigation and Power Department at four study sites. Nevertheless, the overall social impact investigations did reveal that the objectives of drainage systems installation have been achieved in terms of uplifting the socio-economic conditions of drainage areas. To make the efficient use of

  17. Anthropogenic effects on sedimentary facies in Lake Baldeney, West Germany

    Science.gov (United States)

    Neumann-Mahlkau, Peter; Niehaus, Heinz Theo

    1983-12-01

    Analysis of well logs of Lake Baldeney, a reservoir of the Ruhr River, yields four facies factors that reflect the effect of anthropogenic processes on the sediment. First, the sedimentation rate is directly related to the subsidence caused by mining. The extent of the subsidence was such that the sediment load of the river could not compensate for the sinking of the lake bottom. Discharged sediment filled about one-fifth of the basin within 40 years. In certain areas of the basin the sedimentation rate reached up to 10 cm per year. Second, the grain-size distribution of the sediment was influenced by long-term and short-term events. During the subsidence, grain-size distribution remained relatively constant. The destruction of the Möhne River dam during World War II resulted in the presence of an extremely large grain size as evidenced by the so-called Möhnelage. The filling of the lake after 1961 was accompanied by a continual increase in medium grain size. Third, until 1975, the mode of the lake sediment reflects the effect of mining in the vicinity of the lake. High coal content can be traced to its origin. The introduction of modern production processes, modernization of coal dressing, and hydraulic hauling is documented in the sediment. Finally, the heavy metal content of the sediment corresponds to the industrial development in the drainage area the Ruhr River. The accumulation of Cd reached an extreme concentration, exceeding the natural content by a thousand times. Variation in concentration reflects an increase in industrial production, as well as measures undertaken to restore water quality.

  18. Wound Drainage Culture (For Parents)

    Science.gov (United States)

    ... Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Wound Drainage Culture KidsHealth / For Parents / Wound Drainage Culture What's in ...

  19. Late quaternary geomorphology of the Great Salt Lake region, Utah, and other hydrographically closed basins in the western United States: A summary of observations

    Science.gov (United States)

    Currey, Donald R.

    1989-01-01

    Attributes of Quaternary lakes and lake basins which are often important in the environmental prehistory of semideserts are discussed. Basin-floor and basin-closure morphometry have set limits on paleolake sizes; lake morphometry and basin drainage patterns have influenced lacustrine processes; and water and sediment loads have influenced basin neotectonics. Information regarding inundated, runoff-producing, and extra-basin spatial domains is acquired directly from the paleolake record, including the littoral morphostratigraphic record, and indirectly by reconstruction. Increasingly detailed hypotheses regarding Lake Bonneville, the largest late Pleistocene paleolake in the Great Basin, are subjects for further testing and refinement. Oscillating transgression of Lake Bonneville began about 28,000 yr B.P.; the highest stage occurred about 15,000 yr B.P., and termination occurred abruptly about 13,000 yr B.P. A final resurgence of perennial lakes probably occurred in many subbasins of the Great Basin between 11,000 and 10,000 yr B.P., when the highest stage of Great Salt Lake (successor to Lake Bonneville) developed the Gilbert shoreline. The highest post-Gilbert stage of Great Salt Lake, which has been one of the few permanent lakes in the Great Basin during Holocene time, probably occurred between 3,000 and 2,000 yr B.P.

  20. Comparison of tire and road wear particle concentrations in sediment for watersheds in France, Japan, and the United States by quantitative pyrolysis GC/MS analysis.

    Science.gov (United States)

    Unice, Ken M; Kreider, Marisa L; Panko, Julie M

    2013-08-06

    Impacts of surface runoff to aquatic species are an ongoing area of concern. Tire and road wear particles (TRWP) are a constituent of runoff, and determining accurate TRWP concentrations in sediment is necessary in order to evaluate the likelihood that these particles present a risk to the aquatic environment. TRWP consist of approximately equal mass fractions of tire tread rubber and road surface mineral encrustations. Sampling was completed in the Seine (France), Chesapeake (U.S.), and Yodo-Lake Biwa (Japan) watersheds to quantify TRWP in the surficial sediment of watersheds characterized by a wide diversity of population densities and land uses. By using a novel quantitative pyrolysis-GC/MS analysis for rubber polymer, we detected TRWP in 97% of the 149 sediment samples collected. The mean concentrations of TRWP were 4500 (n = 49; range = 62-11 600), 910 (n = 50; range = 50-4400) and 770 (n = 50; range = 26-4600) μg/g d.w. for the characterized portions of the Seine, Chesapeake and Yodo-Lake Biwa watersheds, respectively. A subset of samples from the watersheds (n = 45) was pooled to evaluate TRWP metals, grain size and organic carbon correlations by principal components analysis (PCA), which indicated that four components explain 90% of the variance. The PCA components appeared to correspond to (1) metal alloys possibly from brake wear (primarily Cu, Pb, Zn), (2) crustal minerals (primarily Al, V, Fe), (3) metals mediated by microbial immobilization (primarily Co, Mn, Fe with TOC), and (4) TRWP and other particulate deposition (primarily TRWP with grain size and TOC). This study should provide useful information for assessing potential aquatic effects related to tire service life.

  1. Pre-operative biliary drainage for obstructive jaundice

    Science.gov (United States)

    Fang, Yuan; Gurusamy, Kurinchi Selvan; Wang, Qin; Davidson, Brian R; Lin, He; Xie, Xiaodong; Wang, Chaohua

    2014-01-01

    Background Patients with obstructive jaundice have various pathophysiological changes that affect the liver, kidney, heart, and the immune system. There is considerable controversy as to whether temporary relief of biliary obstruction prior to major definitive surgery (pre-operative biliary drainage) is of any benefit to the patient. Objectives To assess the benefits and harms of pre-operative biliary drainage versus no pre-operative biliary drainage (direct surgery) in patients with obstructive jaundice (irrespective of a benign or malignant cause). Search methods We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Clinical Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until February 2012. Selection criteria We included all randomised clinical trials comparing biliary drainage followed by surgery versus direct surgery, performed for obstructive jaundice, irrespective of the sample size, language, and publication status. Data collection and analysis Two authors independently assessed trials for inclusion and extracted data. We calculated the risk ratio (RR), rate ratio (RaR), or mean difference (MD) with 95% confidence intervals (CI) based on the available patient analyses. We assessed the risk of bias (systematic overestimation of benefit or systematic underestimation of harm) with components of the Cochrane risk of bias tool. We assessed the risk of play of chance (random errors) with trial sequential analysis. Main results We included six trials with 520 patients comparing pre-operative biliary drainage (265 patients) versus no pre-operative biliary drainage (255 patients). Four trials used percutaneous transhepatic biliary drainage and two trials used endoscopic sphincterotomy and stenting as the method of pre-operative biliary drainage. The risk of bias was high in all trials. The proportion of patients with malignant obstruction varied between 60

  2. A review on salt lake city, Kolkata, India: Master planning and realization

    Directory of Open Access Journals (Sweden)

    Tošković Dobrivoje

    2008-01-01

    Full Text Available Motivation for construction of Salt Lake City comes from the circumstances characterizing life in Calcutta known by its social, political and cultural activities. Among many problems, the City was faced with poverty and overcrowding. West Bengal Government realized that serious steps have to be taken to resolve the situation. One of the biggest actions of the Government was creation of so called 'NEDECO' Plan for reclamation certain area of the Salted Lakes, followed by the tender for urban planning. The enterprise for water ways Ivan Milutinović was considered the most convenient for both: reclamation and planning. The Conceptualization covers the Main Aims and interests forming plan basis where three factors were selected: urban character, new vs old town, inhabitants and town growth. Follows Existing Land Use Pattern of the Municipal Area. The realization of the Salt Lake Master Plan, as a part of the Municipal Area, is shown through an Overview of Achieved Infrastructure covering Roads, Water Supply, Sewerage, Area Level Storm Water Drainage, Solid Waste Management and, finally, through the Other Municipal Services, such as: Administrative Infrastructure, Health Infrastructure, Greeneries, Water bodies, Socio-Cultural Infrastructure. .

  3. Temporal and spatial variability of acid rock drainage in a rehabilitated coal mine, Wangaloa, South Otago, New Zealand

    International Nuclear Information System (INIS)

    Begbie, M.; Craw, D.; Rufaut, C.; Martin, C.

    2007-01-01

    The Wangaloa open cast coal mine ceased operations in 1989, with no restoration of the 252 ha site, and moderate acid rock drainage developed. A major rehabilitation programme was initiated in 2002 with removal of exotic vegetation, and extensive planting (>60,000) of native seedlings was begun in 2003. By 2006, most seedlings were thriving, and, combined with adventive exotic weeds, a 70% vegetation cover had been achieved. The site substrates were highly variable on the 10-100 m 2 scale, and have been characterised by paste pH (>700 measurements). In 2003, substrates had moderate acidity (pH 4.5 ± 0.9) with distinctly acid patches (pH down to 100 samples from 15 sites) were also highly variable spatially and temporally. Incoming stream and rainwater (pH 5-6) chemically interacted with acid substrates, especially waste rock piles that contain pyrite-bearing material, and evolved to lower pH (pH down to 3.4), sulfate-rich waters. A pit lake on the site receives most surface and groundwater runoff, and this lake, with a water residence time of 1-2 yr, controls the site discharge water quality. The lake pH varies on a monthly time-scale from 4.5 to 6.5, synchronised with pH variations in groundwater boreholes in waste rock. In addition, there has been a general increase in pH of the lake during rehabilitation from consistent pH 4.6-4.8 before rehabilitation to near pH 6 during rehabilitation. The sulfate/chloride ratio of lake water has decreased from 20 to <10 during rehabilitation as well. These changes in lake water composition from year to year may be a result of increased input of rainwater that has had less interaction with substrate than runoff water had before rehabilitation began. (author). 23 refs., 10 figs., 1 tab

  4. Advances in drainage: Selected works from the Tenth International Drainage Symposium

    Science.gov (United States)

    Strock, Jeffrey S.; Hay, Christopher; Helmers, Matthew; Nelson, Kelly A.; Sands, Gary R.; Skaggs, R. Wayne; Douglas-Mankin, Kyle R.

    2018-01-01

    This article introduces a special collection of fourteen articles accepted from among the 140 technical presentations, posters, and meeting papers presented at the 10th International ASABE Drainage Symposium. The symposium continued in the tradition of previous symposia that began in 1965 as a forum for presenting and assessing the progress of drainage research and implementation throughout the world. The articles in this collection address a wide range of topics grouped into five broad categories: (1) crop response, (2) design and management, (3) hydrology and scale, (4) modeling, and (5) water quality. The collection provides valuable information for scientists, engineers, planners, and others working on crop production, water quality, and water quantity issues affected by agricultural drainage. The collection also provides perspectives on the challenges of increasing agricultural production in a changing climate, with ever-greater attention to water quality and quantity concerns that will require integrated technical, economic, and social solutions.

  5. [Ascites drainage at home].

    Science.gov (United States)

    Lutjeboer, Jacob; van Erkel, Arian R; van der Hoeven, J J M Koos; van der Meer, Rutger W

    2015-01-01

    Ascites can lead to many symptoms, and often occurs in patients with an end-stage malignancy such as ovarian, pancreatic, colonic, or gastric cancer. Intermittent ascites drainage is applied in these patients as a palliative measure. As frequent drainage is necessary, a subcutaneously tunnelled permanent ascites catheter is a good alternative for intermittent drainage. The patient can open - and then re-close - the catheter when abdominal pressure increases. We inserted 35 subcutaneously permanent ascites catheters in the course of the past 3.5 years in the Leiden University Medical Centre. The success rate was 100% and the complication risk was 2.9%. A subcutaneously tunnelled ascites catheter is an effective and safe palliative treatment for patients with end-stage malignant disease and suffering from ascites.

  6. Failures and complications of thoracic drainage

    Directory of Open Access Journals (Sweden)

    Đorđević Ivana

    2006-01-01

    Full Text Available Background/Aim. Thoracic drainage is a surgical procedure for introducing a drain into the pleural space to drain its contents. Using this method, the pleura is discharged and set to the physiological state which enables the reexpansion of the lungs. The aim of the study was to prove that the use of modern principles and protocols of thoracic drainage significantly reduces the occurrence of failures and complications, rendering the treatment more efficient. Methods. The study included 967 patients treated by thoracic drainage within the period from January 1, 1989 to June 1, 2000. The studied patients were divided into 2 groups: group A of 463 patients treated in the period from January 1, 1989 to December 31, 1994 in whom 386 pleural drainage (83.36% were performed, and group B of 602 patients treated form January 1, 1995 to June 1, 2000 in whom 581 pleural drainage (96.51% were performed. The patients of the group A were drained using the classical standards of thoracic drainage by the general surgeons. The patients of the group B, however, were drained using the modern standards of thoracic drainage by the thoracic surgeons, and the general surgeons trained for this kind of the surgery. Results. The study showed that better results were achieved in the treatment of the patients from the group B. The total incidence of the failures and complications of thoracic drainage decreased from 36.52% (group A to 12.73% (group B. The mean length of hospitalization of the patients without complications in the group A was 19.5 days versus 10 days in the group B. The mean length of the treatment of the patients with failures and complications of the drainage in the group A was 33.5 days versus 17.5 days in the group B. Conclusion. The shorter length of hospitalization and the lower morbidity of the studied patients were considered to be the result of the correct treatment using modern principles of thoracic drainage, a suitable surgical technique, and a

  7. Preoperative endoscopic versus percutaneous transhepatic biliary drainage in potentially resectable perihilar cholangiocarcinoma (DRAINAGE trial): design and rationale of a randomized controlled trial.

    Science.gov (United States)

    Wiggers, Jimme K; Coelen, Robert J S; Rauws, Erik A J; van Delden, Otto M; van Eijck, Casper H J; de Jonge, Jeroen; Porte, Robert J; Buis, Carlijn I; Dejong, Cornelis H C; Molenaar, I Quintus; Besselink, Marc G H; Busch, Olivier R C; Dijkgraaf, Marcel G W; van Gulik, Thomas M

    2015-02-14

    Liver surgery in perihilar cholangiocarcinoma (PHC) is associated with high postoperative morbidity because the tumor typically causes biliary obstruction. Preoperative biliary drainage is used to create a safer environment prior to liver surgery, but biliary drainage may be harmful when severe drainage-related complications deteriorate the patients' condition or increase the risk of postoperative morbidity. Biliary drainage can cause cholangitis/cholecystitis, pancreatitis, hemorrhage, portal vein thrombosis, bowel wall perforation, or dehydration. Two methods of preoperative biliary drainage are mostly applied: endoscopic biliary drainage, which is currently used in most regional centers before referring patients for surgical treatment, and percutaneous transhepatic biliary drainage. Both methods are associated with severe drainage-related complications, but two small retrospective series found a lower incidence in the number of preoperative complications after percutaneous drainage compared to endoscopic drainage (18-25% versus 38-60%, respectively). The present study randomizes patients with potentially resectable PHC and biliary obstruction between preoperative endoscopic or percutaneous transhepatic biliary drainage. The study is a multi-center trial with an "all-comers" design, randomizing patients between endoscopic or percutaneous transhepatic biliary drainage. All patients selected to potentially undergo a major liver resection for presumed PHC are eligible for inclusion in the study provided that the biliary system in the future liver remnant is obstructed (even if they underwent previous inadequate endoscopic drainage). Primary outcome measure is the total number of severe preoperative complications between randomization and exploratory laparotomy. The study is designed to detect superiority of percutaneous drainage: a provisional sample size of 106 patients is required to detect a relative decrease of 50% in the number of severe preoperative

  8. Computational fluid dynamics simulations of the Late Pleistocene Lake Bonneville flood

    Science.gov (United States)

    Abril-Hernández, José M.; Periáñez, Raúl; O'Connor, Jim E.; Garcia-Castellanos, Daniel

    2018-01-01

    At approximately 18.0 ka, pluvial Lake Bonneville reached its maximum level. At its northeastern extent it was impounded by alluvium of the Marsh Creek Fan, which breached at some point north of Red Rock Pass (Idaho), leading to one of the largest floods on Earth. About 5320 km3 of water was discharged into the Snake River drainage and ultimately into the Columbia River. We use a 0D model and a 2D non-linear depth-averaged hydrodynamic model to aid understanding of outflow dynamics, specifically evaluating controls on the amount of water exiting the Lake Bonneville basin exerted by the Red Rock Pass outlet lithology and geometry as well as those imposed by the internal lake geometry of the Bonneville basin. These models are based on field evidence of prominent lake levels, hypsometry and terrain elevations corrected for post-flood isostatic deformation of the lake basin, as well as reconstructions of the topography at the outlet for both the initial and final stages of the flood. Internal flow dynamics in the northern Lake Bonneville basin during the flood were affected by the narrow passages separating the Cache Valley from the main body of Lake Bonneville. This constriction imposed a water-level drop of up to 2.7 m at the time of peak-flow conditions and likely reduced the peak discharge at the lake outlet by about 6%. The modeled peak outlet flow is 0.85·106 m3 s−1. Energy balance calculations give an estimate for the erodibility coefficient for the alluvial Marsh Creek divide of ∼0.005 m y−1 Pa−1.5, at least two orders of magnitude greater than for the underlying bedrock at the outlet. Computing quasi steady-state water flows, water elevations, water currents and shear stresses as a function of the water-level drop in the lake and for the sequential stages of erosion in the outlet gives estimates of the incision rates and an estimate of the outflow hydrograph during the Bonneville Flood: About 18 days would have been required for the

  9. Computational Fluid Dynamics simulations of the Late Pleistocene Lake Bonneville Flood

    Science.gov (United States)

    Abril-Hernández, José M.; Periáñez, Raúl; O'Connor, Jim E.; Garcia-Castellanos, Daniel

    2018-06-01

    At approximately 18.0 ka, pluvial Lake Bonneville reached its maximum level. At its northeastern extent it was impounded by alluvium of the Marsh Creek Fan, which breached at some point north of Red Rock Pass (Idaho), leading to one of the largest floods on Earth. About 5320 km3 of water was discharged into the Snake River drainage and ultimately into the Columbia River. We use a 0D model and a 2D non-linear depth-averaged hydrodynamic model to aid understanding of outflow dynamics, specifically evaluating controls on the amount of water exiting the Lake Bonneville basin exerted by the Red Rock Pass outlet lithology and geometry as well as those imposed by the internal lake geometry of the Bonneville basin. These models are based on field evidence of prominent lake levels, hypsometry and terrain elevations corrected for post-flood isostatic deformation of the lake basin, as well as reconstructions of the topography at the outlet for both the initial and final stages of the flood. Internal flow dynamics in the northern Lake Bonneville basin during the flood were affected by the narrow passages separating the Cache Valley from the main body of Lake Bonneville. This constriction imposed a water-level drop of up to 2.7 m at the time of peak-flow conditions and likely reduced the peak discharge at the lake outlet by about 6%. The modeled peak outlet flow is 0.85·106 m3 s-1. Energy balance calculations give an estimate for the erodibility coefficient for the alluvial Marsh Creek divide of ∼0.005 m y-1 Pa-1.5, at least two orders of magnitude greater than for the underlying bedrock at the outlet. Computing quasi steady-state water flows, water elevations, water currents and shear stresses as a function of the water-level drop in the lake and for the sequential stages of erosion in the outlet gives estimates of the incision rates and an estimate of the outflow hydrograph during the Bonneville Flood: About 18 days would have been required for the outflow to grow from 10

  10. Paleolimnological investigations of anthropogenic environmental change in Lake Tanganyika: I. An introduction to the project

    Science.gov (United States)

    Cohen, A.S.; Palacios-Fest, M. R.; McGill, J.; Swarzenski, P.W.; Verschuren, D.; Sinyinza, R.; Songori, T.; Kakagozo, B.; Syampila, M.; O'Reilly, C. M.; Alin, S.R.

    2005-01-01

    We investigated paleolimnological records from a series of river deltas around the northeastern rim of Lake Tanganyika, East Africa (Tanzania and Burundi) in order to understand the history of anthropogenic activity in the lake's catchment over the last several centuries, and to determine the impact of these activities on the biodiversity of littoral and sublittoral lake communities. Sediment pollution caused by increased rates of soil erosion in deforested watersheds has caused significant changes in aquatic communities along much of the lake's shoreline. We analyzed the effects of sediment discharge on biodiversity around six deltas or delta complexes on the east coast of Lake Tanganyika: the Lubulungu River delta, Kabesi River delta, Nyasanga/Kahama River deltas, and Mwamgongo River delta in Tanzania; and the Nyamuseni River delta and Karonge/Kirasa River deltas in Burundi. Collectively, these deltas and their associated rivers were chosen to represent a spectrum of drainage-basin sizes and disturbance levels. By comparing deltas that are similar in watershed attributes (other than disturbance levels), our goal was to explore a series of historical "experiments" at the watershed scale, with which we could more clearly evaluate hypotheses of land use or other effects on nearshore ecosystems. Here we discuss these deltas, their geologic and physiographic characteristics, and the field procedures used for coring and sampling the deltas, and various indicators of anthropogenic impact. ?? Springer 2005.

  11. The regional and global significance of nitrogen removal in lakes and reservoirs

    Science.gov (United States)

    Harrison, J.A.; Maranger, R.J.; Alexander, Richard B.; Giblin, A.E.; Jacinthe, P.-A.; Mayorga, Emilio; Seitzinger, S.P.; Sobota, D.J.; Wollheim, W.M.

    2009-01-01

    Human activities have greatly increased the transport of biologically available nitrogen (N) through watersheds to potentially sensitive coastal ecosystems. Lentic water bodies (lakes and reservoirs) have the potential to act as important sinks for this reactive N as it is transported across the landscape because they offer ideal conditions for N burial in sediments or permanent loss via denitrification. However, the patterns and controls on lentic N removal have not been explored in great detail at large regional to global scales. In this paper we describe, evaluate, and apply a new, spatially explicit, annual-scale, global model of lentic N removal called NiRReLa (Nitrogen Retention in Reservoirs and Lakes). The NiRReLa model incorporates small lakes and reservoirs than have been included in previous global analyses, and also allows for separate treatment and analysis of reservoirs and natural lakes. Model runs for the mid-1990s indicate that lentic systems are indeed important sinks for N and are conservatively estimated to remove 19.7 Tg N year-1 from watersheds globally. Small lakes (<50 km2) were critical in the analysis, retaining almost half (9.3 Tg N year -1) of the global total. In model runs, capacity of lakes and reservoirs to remove watershed N varied substantially at the half-degree scale (0-100%) both as a function of climate and the density of lentic systems. Although reservoirs occupy just 6% of the global lentic surface area, we estimate they retain ~33% of the total N removed by lentic systems, due to a combination of higher drainage ratios (catchment surface area:lake or reservoir surface area), higher apparent settling velocities for N, and greater average N loading rates in reservoirs than in lakes. Finally, a sensitivity analysis of NiRReLa suggests that, on-average, N removal within lentic systems will respond more strongly to changes in land use and N loading than to changes in climate at the global scale. ?? 2008 Springer Science

  12. Acid drainage (AD) in nature and environmental impact of acid mine drainage (AMD) in Southern Tuscany

    International Nuclear Information System (INIS)

    Di Lella, Luigi Antonello; Protano, Giuseppe; Riccobono, Francesco

    2005-01-01

    Acid drainage (AD) is a natural process occurring locally at the Earth's surface. It consists in a substantial increase of acidity of surface waters as a result of chemical reactions occurring in the atmosphere (i.e. acid rain) or involving reactive phases (i.e. pyrite) present in the percolated medium. Acidic surface waters (usually pH < 4) can be produced by oxidation of sulphides (mainly pyrite and other iron sulphides) exposed to atmospheric oxygen, while human activities, such as mining, can greatly enhance this process. Acid drainage promoted by mining activities is called acid mine drainage (AMD) and is a primary source of environmental pollution and a world-wide problem in both active and abandoned mining areas. In fact, exposure of iron sulphides to oxidising conditions produces strongly acidic drainage waters rich in sulphate and a variety of heavy elements (i.e. As, Cd, Pb, Sb). Several occurrences of active acid mine drainage have been found in the Metalliferous Hills (southern Tuscany). The most important AMD phenomena were observed in the Fenice Capanne and Niccioleta mining areas

  13. Microplastic pollution in lakes and lake shoreline sediments - A case study on Lake Bolsena and Lake Chiusi (central Italy).

    Science.gov (United States)

    Fischer, Elke Kerstin; Paglialonga, Lisa; Czech, Elisa; Tamminga, Matthias

    2016-06-01

    Rivers and effluents have been identified as major pathways for microplastics of terrestrial sources. Moreover, lakes of different dimensions and even in remote locations contain microplastics in striking abundances. This study investigates concentrations of microplastic particles at two lakes in central Italy (Lake Bolsena, Lake Chiusi). A total number of six Manta Trawls have been carried out, two of them one day after heavy winds occurred on Lake Bolsena showing effects on particle distribution of fragments and fibers of varying size categories. Additionally, 36 sediment samples from lakeshores were analyzed for microplastic content. In the surface waters 2.68 to 3.36 particles/m(3) (Lake Chiusi) and 0.82 to 4.42 particles/m(3) (Lake Bolsena) were detected, respectively. Main differences between the lakes are attributed to lake characteristics such as surface and catchment area, depth and the presence of local wind patterns and tide range at Lake Bolsena. An event of heavy winds and moderate rainfall prior to one sampling led to an increase of concentrations at Lake Bolsena which is most probable related to lateral land-based and sewage effluent inputs. The abundances of microplastic particles in sediments vary from mean values of 112 (Lake Bolsena) to 234 particles/kg dry weight (Lake Chiusi). Lake Chiusi results reveal elevated fiber concentrations compared to those of Lake Bolsena what might be a result of higher organic content and a shift in grain size distribution towards the silt and clay fraction at the shallow and highly eutrophic Lake Chiusi. The distribution of particles along different beach levels revealed no significant differences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Percutaneous drainage of abscesses associated with biliary fistulae

    International Nuclear Information System (INIS)

    Berger, H.; Winter, T.; Pratschke, E.; Sauerbruch, T.; Klinikum Grosshadern, Muenchen; Klinikum Grosshadern, Muenchen

    1989-01-01

    33 abdominal abscesses associated with fistulae in 31 patients were treated by percutaneous drainage. 19 of these patients had had surgery immediately preceding the drainage. In 64% the percutaneous drainage led to a diagnosis of an internal fistula. Additional therapeutic measures, because of the fistula, were necessary in 45% (operation, biliary drainage, repositioning of catheter). The average duration of drainage was 29 days. 77% of those abscesses which could be drained were treated successfully. Mortality in the entire series was 19%. (orig.) [de

  15. A review on anthropogenic impact to the Micro Prespa lake and its damages

    Science.gov (United States)

    Frasheri, N.; Pano, N.; Frasheri, A.; Beqiraj, G.; Bushati, S.; Taska, E.

    2012-04-01

    Paper presents the results of the integrated and multidisciplinary studies for investigation of the anthropogenic damages to Albanian part of the transborder Micro Prespa Lake. Remote sensing with Landsat images was used for identification of environmental changes in time for the period 1970 - 2010. Micro Prespa Lake is lake with international status, as Ramsar Convection, International Park and Special Protection Area-79/409/EEC. According to the studies, investigations and analyses, the following were concluded: Devolli River- Micro Prespa Lake irrigation system was not scientifically supported by environmental engineering, hydroeconomy and International Rights principles. It does work according to the projected parameters, and also, doesn't supply the agricultural needs. About of 10 % of the water volume, discharges by Devolli River in Micro Prespa Lake during the winter, is taken from this lake for the irrigation in summer. Great surface of Albanian part of Micro Prespa Lake is destroyed. The other part of the lake is atrophied and the habitat and biodiversity are damaged. Important and unique species of fish, birds and plants of national and international values are risked. The underground karstic connection ways for water circulation are blocked. There are ruining the historic values of the area, such the encient Treni cave from the Bronze Age. The Albanian part of the Micro Prespa Lake has been damaged by the human activities. A huge amount of 1,2 million cubic meters alluvium has been deposited on the lake bottom and lakeshore, which was transported by the Devolli River waters, since 1974. This river waters, rich in alluvium and organic coal material from outcropped geological formations, also absorbed free chemical toxic remains by the drainage of Devolli farm ground, which have changed the chemical features of the lake water and degrading it. Micro Prespa Lake communicates with Macro Prespa Lake, and together with Ohrid Lake. Blockage of underground

  16. Reuse of drainage water in the Nile Delta; monitoring, modelling and analysis; final report Reuse of Drainage Water Project

    NARCIS (Netherlands)

    Staring Centrum, Instituut voor Onderzoek van het LandelijkGebied

    1995-01-01

    The effects of reusing drainage water have been evaluated and other options to increase the water utilization rate in Egypt explored. The results are an operational network for monitoring drainage water discharges and salinity along the major drains, a database for monitored drainage water

  17. A multi-proxy lake core record from Lago Lungo, Rieti Basin, Lazio, Italy and its relation to human activities in the catchment during the last century

    Science.gov (United States)

    Noble, Paula; Tunno, Irene; Mensing, Scott; Piovesan, Gianluca

    2016-04-01

    The lakes of the Rieti Basin have experienced extensive human modification dating back to pre-Roman times, yet lake archives indicate that the most profound changes to the aquatic ecosystem have occurred during the last century. Analysis of the upper ˜120 cm segment of a sediment core from Lago Lungo, dating back to ˜1830 CE, show changes in water quality and hydrologic inflow largely attributed to 20th century reclamation and land use activities. Lago Lungo is a shallow, small, eutrophic, hard water lake situated in an intermontaine alluvial plain ˜90 km NE of Rome. It is one of several remnant lakes in a poorly drained wetland area fed by numerous springs. Reclamation activities over the last century have substantially altered the drainage network affecting water delivery to the lakes and their connectivity. There are 3 interesting signals in the core. First, small Stephanodiscus species, associated with hypereutrophic conditions, appear after 1950, peak ˜1990, and may be attributed to increased use of chemical fertilizers and intensification of local agriculture. Elemental proxies from scanning XRF data (abundances of Ti, Si/Ti, and Ca) are consistent with increased eutrophication starting ˜1950. A decline in Stephanodicsus after 1990 reflects some improvement to the water quality following the lake's incorporation into a nature preserve and creation of a narrow vegetation buffer. Intermittent water quality measurements from 1982 onward corroborate the changes in trophic status interpreted from the core record. Second, a large change in the core stratigraphy, elemental geochemistry, and diatom composition occurs ˜1940 and is associated with several major reclamation efforts, including the rerouting of the Santa Susanna channel, which redirected large volumes of artesian inflows away from the lakes and estuarine system. Upstream, dams on the Turano and Salto rivers were also constructed, further affecting hydrological inflows into the basin. From ˜1900

  18. Deriving a time series of 3D glacier motion to investigate interactions of a large mountain glacial system with its glacial lake: Use of Synthetic Aperture Radar Pixel Offset-Small Baseline Subset technique

    Science.gov (United States)

    Li, Jia; Li, Zhi-wei; Wu, Li-xin; Xu, Bing; Hu, Jun; Zhou, Yu-shan; Miao, Ze-lang

    2018-04-01

    We investigated the interactions of Lake Merzbacher with the Southern Inylchek Glacier (Central Tien Shan) using the Synthetic Aperture Radar (SAR) Pixel Offset-Small Baseline Subset (PO-SBAS) to derive a time series of three-dimensional (3D) glacier motion. The measurements of 3D glacier velocity were ∼17% more precise than a previous study that did not use the SBAS estimation. The velocities of the glacier were up to 58 cm/day east, 70 cm/day north, and 113 cm/day vertically. Combining these data with Landsat images indicated that movement of the glacier is sensitive to changes of Lake Merzbacher. Specifically, the entry of more lake water into the glacier during the ablation season increased englacial ablation due to thermal erosion. Moreover, ice calving begins when the lake water gradually lifts the ice dam. Calving can cause greater loss of glacier mass than normal ablation. Trying to replenish the front mass loss, the distributary accelerates and the mass loss further intensifies. A time series of the vertical velocity indicates that the glacier tongue has a huge englacial cavity. We suggest that the lake outburst is directly related to the crack of this cavity. Bursting of the lake triggers a mini-surge at the glacier tongue. The vertical velocity at the ice dam was ∼+60 cm/day before the lake outburst, and ∼-113 cm/day afterwards. After drainage of the lake, flow velocities at the distributary, do not sharply decrease because pre-drainage mass loss needs to be replenished by fast flow. Based on comparisons with previous measurements, our results indicate that the lake had an increasing influence on the glacier from 2005 to 2009. This study demonstrates that a time series of 3D glacier motion based on the PO-SBAS technique is effective for assessing the dynamics of a mountain glacial system and interactions with its glacial lake.

  19. Radiologically-guided catheter drainage of intrathoracic abscesses and empyemas

    International Nuclear Information System (INIS)

    Berger, H.; Steiner, W.; Bergman, C.; Anthuber, M.; Dienemann, H.

    1993-01-01

    Radiologically guided percutaneous catheter drainage was used in 38 patients to treat pleural empyemas (35 patients) and pulmonary abscesses (3 patients). Drainage was successful in 85.7% of empyemas including 11 cases with fistulous communications. Three percutaneously drained pulmonary abscesses required subsequent lobectomy. One patient died during the drainage procedure due to sepsis. No major complications related to the drainage procedure were observed. Guided percutaneous drainage proved to be a safe and successful alternative to closed drainage of pleural fluid collections. (orig.)

  20. Bioremediation of Acidic and Metalliferous Drainage (AMD) through organic carbon amendment by municipal sewage and green waste.

    Science.gov (United States)

    McCullough, Clint D; Lund, Mark A

    2011-10-01

    Pit lakes (abandoned flooded mine pits) represent a potentially valuable water resource in hot arid regions. However, pit lake water is often characterised by low pH with high dissolved metal concentrations resulting from Acidic and Metalliferous Drainage (AMD). Addition of organic matter to pit lakes to enhance microbial sulphate reduction is a potential cost effective remediation strategy. However, cost and availability of suitable organic substrates are often limiting. Nevertheless, large quantities of sewage and green waste (organic garden waste) are often available at mine sites from nearby service towns. We treated AMD pit lake water (pH 2.4) from tropical, North Queensland, Australia, with primary-treated sewage sludge, green waste, and a mixture of sewage and green waste (1:1) in a controlled microcosm experiment (4.5 L). Treatments were assessed at two different rates of organic loading of 16:1 and 32:1 pit water:organic matter by mass. Combined green waste and sewage treatment was the optimal treatment with water pH increased to 5.5 in only 145 days with decreases of dissolved metal concentrations. Results indicated that green waste was a key component in the pH increase and concomitant heavy metal removal. Water quality remediation was primarily due to microbially-mediated sulphate reduction. The net result of this process was removal of sulphate and metal solutes to sediment mainly as monosulfides. During the treatment process NH(3) and H(2)S gases were produced, albeit at below concentrations of concern. Total coliforms were abundant in all green waste-treatments, however, faecal coliforms were absent from all treatments. This study demonstrates addition of low-grade organic materials has promise for bioremediation of acidic waters and warrants further experimental investigation into feasibility at higher scales of application such as pit lakes. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  1. Hubbard Glacier, Alaska: growing and advancing in spite of global climate change and the 1986 and 2002 Russell Lake outburst floods

    Science.gov (United States)

    Trabant, Dennis C.; March, Rod S.; Thomas, Donald S.

    2003-01-01

    Hubbard Glacier, the largest calving glacier on the North American Continent (25 percent larger than Rhode Island), advanced across the entrance to 35-mile-long Russell Fiord during June 2002, temporarily turning it into a lake. Hubbard Glacier has been advancing for more than 100 years and has twice closed the entrance to Russell Fiord during the last 16 years by squeezing and pushing submarine glacial sediments across the mouth of the fiord. Water flowing into the cutoff fiord from mountain streams and glacier melt causes the level of Russell Lake to rise. However, both the 1986 and 2002 dams failed before the lake altitude rose enough for water to spill over a low pass at the far end of the fiord and enter the Situk River drainage, a world-class sport and commercial fishery near Yakutat, Alaska.

  2. Percutaneous drainage of lung abscess

    Energy Technology Data Exchange (ETDEWEB)

    Ri, Jong Min; Kim, Yong Joo; Kang, Duk Sik [Kyung-Pook National University Hospital, Daegu (Korea, Republic of)

    1992-05-15

    Medical treatment using antibiotics and postural drainage has been widely adopted as a treatment method of pulmonary abscess, accompanied by surgical methods in cases intractable to drug therapy. However long-term therapy may be required, and the tolerance of organisms to antibiotics or other complications are apt to be encountered, during medical treatment. To shorten the convalescent period or to decrease the risk of invasive procedures, rather simple and relatively easy interventional techniques such as transbronchial or percutaneous catheter drainage have been successfully tried. We have performed 12 cases of percutaneous drainages of lung abscesses under fluoroscope guidance. This report is on the results of this procedure.

  3. Percutaneous drainage of lung abscess

    International Nuclear Information System (INIS)

    Ri, Jong Min; Kim, Yong Joo; Kang, Duk Sik

    1992-01-01

    Medical treatment using antibiotics and postural drainage has been widely adopted as a treatment method of pulmonary abscess, accompanied by surgical methods in cases intractable to drug therapy. However long-term therapy may be required, and the tolerance of organisms to antibiotics or other complications are apt to be encountered, during medical treatment. To shorten the convalescent period or to decrease the risk of invasive procedures, rather simple and relatively easy interventional techniques such as transbronchial or percutaneous catheter drainage have been successfully tried. We have performed 12 cases of percutaneous drainages of lung abscesses under fluoroscope guidance. This report is on the results of this procedure

  4. Percutaneous drainage of diverticular abscess: Adjunct to resection

    International Nuclear Information System (INIS)

    Mueller, P.R.; Saini, S.; Butch, R.J.; Simeone, J.F.; Rodkey, G.V.; Bousquet, J.C.; Ottinger, L.W.; Wittenberg, J.; Ferrucci, J.T. Jr.

    1986-01-01

    Traditional surgical management of acute diverticulitis with abscess may require a one-, two-, or three-stage procedure. Because of recent interest in CT diagnosis of diverticulitis, and novel access routes for interventional drainage of deep pelvic abscesses, the authors investigated the potential for converting complex two- and three-stage surgical procedures to simpler, safer one-stage colon resections by percutaneous drainage of the associated abscess. Of 23 patients with acute perforated diverticulitis who were referred for catheter drainage under radiologic guidance, successful catheter drainage and subsequent single-stage colon resection were carried out in 15. In three patients catheter drainage was unsuccessful and a multistage procedure was required. In three patients only percutaneous drainage was performed and operative intervention was omitted entirely

  5. Geohydrologic reconnaissance of drainage wells in Florida

    Science.gov (United States)

    Kimrey, J.O.; Fayard, L.D.

    1984-01-01

    Drainage wells are used to inject surface waters directly into an aquifer, or shallow ground waters directly into a deeper aquifer, primarily by gravity. Such wells in Florida may be grouped into two broad types: (1) surface-water injection wells, and (2) interaquifer connector wells. Drainage wells of the first type are further categorized as either Floridan aquifer drainage wells or Biscayne aquifer drainage wells. Floridan aquifer drainage wells are commonly used to supplement drainage for urban areas in karst terranes of central and north Florida. Data are available for 25 wells in the Ocala, Live Oak, and Orlando areas that allow comparison of the quality of water samples from these Floridan aquifer drainage wells with allowable contaminant levels. Comparison indicates that maximum contaminant levels for turbidity, color, and iron, manganese, and lead concentrations are equaled or exceeded in some drainage-well samples, and relatively high counts for coliform bacteria are present in most wells. Biscayne aquifer drainage wells are used locally to dispose of stormwater runoff and other surplus water in southeast Florida, where large numbers of these wells have been permitted in Dade and Broward Counties. The majority of these wells are used to dispose of water from swimming pools or to dispose of heated water from air-conditioning units. The use of Biscayne aquifer drainage wells may have minimal effect on aquifer potability so long as injection of runoff and industrial wates is restricted to zones where chloride concentrations exceed 1,500 milligrams per liter. Interaquifer connector wells are used in the phosphate mining areas of Polk and Hillsborough Counties, to drain mines and recharge the Floridan aquifer. Water-quality data available from 13 connector wells indicate that samples from most of these wells exceed standards values for iron concentration and turbidity. One well yielded a highly mineralized water, and samples from 6 of the other 12 wells exceed

  6. Ecological factors affecting Rainbow Smelt recruitment in the main basin of Lake Huron, 1976-2010

    Science.gov (United States)

    O'Brien, Timothy P.; Taylor, William W.; Roseman, Edward F.; Madenjian, Charles P.; Riley, Stephen C.

    2014-01-01

    Rainbow Smelt Osmerus mordax are native to northeastern Atlantic and Pacific–Arctic drainages and have been widely introduced throughout North America. In the Great Lakes region, Rainbow Smelt are known predators and competitors of native fish and a primary prey species in pelagic food webs. Despite their widespread distribution, importance as a prey species, and potential to negatively interact with native fish species, there is limited information concerning stock–recruitment relationships for Rainbow Smelt. To better understand recruitment mechanisms, we evaluated potential ecological factors determining recruitment dynamics for Rainbow Smelt in Lake Huron using data from bottom trawl catches. We specifically evaluated influence of stock size, environmental factors (water temperature, lake levels, and precipitation), and salmonine predation on the production of age-0 recruits from 1976 to 2010. Rainbow Smelt recruitment was negatively related to stock size exceeding 10 kg/ha, indicating that compensatory, density-dependent mortality from cannibalism or intraspecific competition was an important factor related to the production of age-0 recruits. Recruitment was positively related to spring precipitation suggesting that the amount of stream-spawning habitat as determined by precipitation was important for the production of strong Rainbow Smelt recruitment. Additionally, density of age-0 Rainbow Smelt was positively related to Lake Trout Salvelinus namaycush abundance. However, spawning stock biomass of Rainbow Smelt, which declined substantially from 1989 to 2010, was negatively associated with Lake Trout catch per effort suggesting predation was an important factor related to the decline of age-2 and older Rainbow Smelt in Lake Huron. As such, we found that recruitment of Rainbow Smelt in Lake Huron was regulated by competition with or cannibalism by older conspecifics, spring precipitation influencing stream spawning habitats, and predation by Lake Trout on

  7. Geochemical characterization of acid mine lakes in northwest Turkey and their effect on the environment.

    Science.gov (United States)

    Yucel, Deniz Sanliyuksel; Baba, Alper

    2013-04-01

    Mining activity generates a large quantity of mine waste. The potential hazard of mine waste depends on the host mineral. The tendency of mine waste to produce acid mine drainage (AMD) containing potentially toxic metals depends on the amounts of sulfide, carbonate minerals, and trace-element concentrations found in ore deposits. The acid mine process is one of the most significant environmental challenges and a major source of water pollution worldwide. AMD and its effects were studied in northwest Turkey where there are several sedimentary and hydrothermal mineral deposits that have been economically extracted. The study area is located in Can county of Canakkale province. Canakkale contains marine, lagoon, and lake sediments precipitated with volcanoclastics that occurred as a result of volcanism, which was active during various periods from the Upper Eocene to Plio-Quaternary. Can county is rich in coal with a total lignite reserve >100 million tons and contains numerous mines that were operated by private companies and later abandoned without any remediation. As a result, human intervention in the natural structure and topography has resulted in large open pits and deterioration in these areas. Abandoned open pit mines typically fill with water from runoff and groundwater discharge, producing artificial lakes. Acid drainage waters from these mines have resulted in the degradation of surface-water quality around Can County. The average pH and electrical conductivity of acid mine lakes (AMLs) in this study were found to be 3.03 and 3831.33 μS cm(-1), respectively. Total iron (Fe) and aluminum (Al) levels were also found to be high (329.77 and 360.67 mg L(-1), respectively). The results show that the concentration of most elements, such as Fe and Al in particular, exceed national and international water-quality standards.

  8. Rise and fall of a small ice-dammed lake - Role of deglaciation processes and morphology

    Science.gov (United States)

    Nehyba, Slavomír; Hanáček, Martin; Engel, Zbyněk; Stachoň, Zdeněk

    2017-10-01

    A small ice-dammed lake, which developed along the margin of Nordenskiöldbreen on the northern coast of Adolfbukta, (central Spitsbergen, Svalbard) has been studied by a combination of facies analysis, ground penetrating radar, analysis of photos and satellite imagery, and by surface mapping by Unmanned Aerial Vehicle (drone). The lake existed between the years 1990-2012 and occupied two partial depressions in the bedrock, separated by a bedrock ridge for the dominant period of its history. Whereas the eastern depression was almost completely infilled due to direct fluvial input, the western depression revealed only thin sedimentary cover and was dotted from the eastern depression by an outflow of surficial waters. Gilbert delta deposits with typical tripartite zones of topset, foreset and bottomset were recognised in the eastern depression. Topset was comprised by deposits of a braided river. Foreset is formed by deposits of sediment gravity flows (turbidity currents and debris flows). Bottomset is represented by alternating suspension deposits and deposits of hyperpycnal underflows (low-density turbidity currents). The ruling factors of the evolution of the delta were glacier retreat, bedrock morphology, both affecting the relative lake level, and the rate of sediment delivery. Glacier retreat over stepped and inclined bedrock morphology led to delta prograding and downstepping. The recognised fluvio-deltaic terraces revealed four lake level falls followed by fluvial downcutting, erosion and redeposition of the older deltaic/lake deposits, the shifting of the lake's position towards the damming glacier and the transition of the sediment input in the same direction. The termination of the lake was a result of further glacier retreat and the opening of subglacial drainage.

  9. EFFECTIVENESS OF AUTOGENIC DRAINAGE VERSUS POSTURAL DRAINAGE ON OXYGEN SATURATION IN PATIENTS WITH CHRONIC BRONCHITIS WITH 15 MINUTES POST THERAPY

    OpenAIRE

    V. Kiran; Dr. Bhimasen .S; E. Mastanaiah; A. Thiruppathi

    2014-01-01

    Background: Patients with COPD will have more amount of secretions. To clear the secretions by using of different bronchial hygiene techniques like postural drainage and autogenic drainage technique, manual hyperventilation technique ,active cycle breathing technique .Hence in this study to compare the short-term effects of postural drainage with clapping (PD) and autogenic drainage (AD) on level of oxygen saturation in blood, and amount of sputum recovery. Methodology: The study was done ...

  10. 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

  11. Postoperative drainage in head and neck surgery.

    Science.gov (United States)

    Amir, Ida; Morar, Pradeep; Belloso, Antonio

    2010-11-01

    A major factor affecting patients' length of hospitalisation following head and neck surgery remains the use of surgical drains. The optimal time to remove these drains has not been well defined. A routine practice is to measure the drainage every 24 h and remove the drain when daily drainage falls below 25 ml. This study aims to determine whether drainage measurement at shorter intervals decreases the time to drain removal and hence the length of in-patient stays. A 6-month prospective observational study was performed. The inclusion criteria were patients who underwent head and neck surgery without neck dissection and had a closed suction drain inserted. Drainage rates were measured at 8-hourly intervals. Drains were removed when drainage-rate was ≤ 1 ml/h over an 8-h period. A total of 43 patients were evaluated. The highest drainage rate occurred in the first 8 postoperative hours and decreased significantly in the subsequent hours. The median drainage rates at 8, 16, 24, 32 and 40 postoperative hours were 3.375, 1, 0, 0 and 0 ml/h, respectively. Applying our new removal criteria of ≤ 1 ml/h drainage rate, the drains were removed in 22 (51%) patients at the 16th postoperative hour; 37 (86%) were removed by 24 h after operation. In comparison, only nine (20.9%) patients could potentially be discharged the day after surgery if previous criteria of ≤ 25 ml/24-h were used to decide on drain removal. Our 8-hourly drainage-rate monitoring has facilitated safe earlier discharge of an additional 28 (65%) patients on the day after surgery. This has led to improvement in patient care, better optimisation of hospital resources and resulted in positive economic implications to the department.

  12. Surficial geology and stratigraphy of Pleistocene Lake Manix, San Bernardino County, California

    Science.gov (United States)

    Reheis, Marith C.; Redwine, Joanna R.; Wan, Elmira; McGeehin, John P.; VanSistine, D. Paco

    2014-01-01

    Pluvial Lake Manix and its surrounding drainage basin, in the central Mojave Desert of California, has been a focus of paleoclimate, surficial processes, and neotectonic studies by the U.S. Geological Survey (USGS) since about 2004. The USGS initiated studies of Lake Manix deposits to improve understanding of the paleoclimatic record and the shifts in atmospheric circulation that controlled precipitation in the Mojave Desert. Until approximately 25,000 years ago, Lake Manix was the terminus of the Mojave River, which drains northeasterly from the San Bernardino Mountains; the river currently terminates in the Soda Lake and Silver Lake playas. Pleistocene Lake Manix occupied several subbasins at its maximum extent. This map focuses on the extensive exposures created by incision of the Mojave River and its tributaries into the interbedded lacustrine and alluvial deposits within the central (Cady) and northeastern (Afton) subbasins of Lake Manix, and extends from the head of Afton Canyon to Manix Wash. The map illuminates the geomorphic development and depositional history of the lake and alluvial fans within the active tectonic setting of the eastern California shear zone, especially interactions with the left-lateral Manix fault. Lake Manix left an extraordinarily detailed but complex record of numerous transgressive-regressive sequences separated by desiccation and deposition of fan, eolian, and fluvial deposits, and punctuated by tectonic movements and a catastrophic flood that reconfigured the lake basin. Through careful observation of the intercalated lacustrine and fan sequences and by determining the precise elevations of unit contacts, this record was decoded to understand the response of the lake and river system to the interplay of climatic, geomorphic, and tectonic forces. These deposits are exposed in steep badland topography. Mapping was carried out mostly at scales of 1:12,000, although the map is presented at 1:24,000 scale, and employs custom unit

  13. Traditional Foley drainage systems--do they drain the bladder?

    Science.gov (United States)

    Garcia, Maurice M; Gulati, Shelly; Liepmann, Dorian; Stackhouse, G Bennett; Greene, Kirsten; Stoller, Marshall L

    2007-01-01

    Foley catheters are assumed to drain the bladder to completion. Drainage characteristics of Foley catheter systems are poorly understood. To investigate unrecognized retained urine with Foley catheter drainage systems, bladder volumes of hospitalized patients were measured with bladder scan ultrasound volumetrics. Additionally, an in vitro bench top mock bladder and urinary catheter system was developed to understand the etiology of such residual volumes. A novel drainage tube design that optimizes indwelling catheter drainage was also designed. Bedside bladder ultrasound volumetric studies were performed on patients hospitalized in ward and intensive care unit. If residual urine was identified the drainage tubing was manipulated to facilitate drainage. An ex vivo bladder-urinary catheter model was designed to measure flow rates and pressures within the drainage tubing of a traditional and a novel drainage tube system. A total of 75 patients in the intensive care unit underwent bladder ultrasound volumetrics. Mean residual volume was 96 ml (range 4 to 290). In 75 patients on the hospital ward mean residual volume was 136 ml (range 22 to 647). In the experimental model we found that for every 1 cm in curl height, obstruction pressure increased by 1 cm H2O within the artificial bladder. In contrast, the novel spiral-shaped drainage tube demonstrated rapid (0.5 cc per second), continuous and complete (100%) reservoir drainage in all trials. Traditional Foley catheter drainage systems evacuate the bladder suboptimally. Outflow obstruction is caused by air-locks that develop within curled redundant drainage tubing segments. The novel drainage tubing design eliminates gravity dependent curls and associated air-locks, optimizes flow, and minimizes residual bladder urine.

  14. Terrestrial CDOM in Lakes of Yamal Peninsula: Connection to Lake and Lake Catchment Properties

    Directory of Open Access Journals (Sweden)

    Yury Dvornikov

    2018-01-01

    Full Text Available In this study, we analyze interactions in lake and lake catchment systems of a continuous permafrost area. We assessed colored dissolved organic matter (CDOM absorption at 440 nm (a(440CDOM and absorption slope (S300–500 in lakes using field sampling and optical remote sensing data for an area of 350 km2 in Central Yamal, Siberia. Applying a CDOM algorithm (ratio of green and red band reflectance for two high spatial resolution multispectral GeoEye-1 and Worldview-2 satellite images, we were able to extrapolate the a(λCDOM data from 18 lakes sampled in the field to 356 lakes in the study area (model R2 = 0.79. Values of a(440CDOM in 356 lakes varied from 0.48 to 8.35 m−1 with a median of 1.43 m−1. This a(λCDOM dataset was used to relate lake CDOM to 17 lake and lake catchment parameters derived from optical and radar remote sensing data and from digital elevation model analysis in order to establish the parameters controlling CDOM in lakes on the Yamal Peninsula. Regression tree model and boosted regression tree analysis showed that the activity of cryogenic processes (thermocirques in the lake shores and lake water level were the two most important controls, explaining 48.4% and 28.4% of lake CDOM, respectively (R2 = 0.61. Activation of thermocirques led to a large input of terrestrial organic matter and sediments from catchments and thawed permafrost to lakes (n = 15, mean a(440CDOM = 5.3 m−1. Large lakes on the floodplain with a connection to Mordy-Yakha River received more CDOM (n = 7, mean a(440CDOM = 3.8 m−1 compared to lakes located on higher terraces.

  15. Tracing and quantifying lake water and groundwater fluxes in the area under mining dewatering pressure using coupled O and H stable isotope approach.

    Science.gov (United States)

    Lewicka-Szczebak, Dominika; Jędrysek, Mariusz-Orion

    2013-01-01

    Oxygen and hydrogen stable isotopic compositions of precipitation, lake water and groundwater were used to quantitatively asses the water budget related to water inflow and water loss in natural lakes, and mixing between lake water and aquifer groundwater in a mining area of the Lignite Mine Konin, central Poland. While the isotopic composition of precipitation showed large seasonal variations (δ(2)H from-140 to+13 ‰ and δ(18)O from-19.3 to+7.6 ‰), the lake waters were variously affected by evaporation (δ(2)H from-44 to-21 ‰ and δ(18)O from-5.2 to-1.7 ‰) and the groundwater showed varying contribution from mixing with surface water (δ(2)H from-75 to-39 ‰ and δ(18)O from-10.4 to-4.8 ‰). The lake water budget was estimated using a Craig-Gordon model and isotopic mass balance constraint, which enabled us to identify various water sources and to quantify inflow and outflow for each lake. Moreover, we documented that a variable recharge of lake water into the Tertiary aquifer was dependent on mining drainage intensity. A comparison of coupled δ(2)H-δ(18)O data with hydrogeological results indicated better precision of the δ(2)H-based calculations.

  16. A synthesis of post-glacial diatom records from Lake Baikal

    Science.gov (United States)

    Bradbury, J. Platt; Bezrukova, E.; Chernyaeva, G.; Colman, S.M.; Khursevich, G.; King, J.W.; Likoshway, Ye. V.

    1994-01-01

    The biostratigraphy of fossil diatoms contributes important chronologic, paleolimnologic, and paleoclimatic information from Lake Baikal in southeastern Siberia. Diatoms are the dominant and best preserved microfossils in the sediments, and distinctive assemblages and species provide inter-core correlations throughout the basin at millennial to centennial scales, in both high and low sedimentation-rate environments. Distributions of unique species, once dated by radiocarbon, allow diatoms to be used as dating tools for the Holocene history of the lake.Diatom, pollen, and organic geochemical records from site 305, at the foot of the Selenga Delta, provide a history of paleolimnologic and paleoclimatic changes from the late glacial (15 ka) through the Holocene. Before 14 ka diatoms were very rare, probably because excessive turbidity from glacial meltwater entering the lake impeded productivity. Between 14 and 12 ka, lake productivity increased, perhaps as strong winds promoted deep mixing and nutrient regeneration. Pollen evidence suggests a cold shrub — steppe landscape dominated the central Baikal depression at this time. As summer insolation increased, conifers replaced steppe taxa, but diatom productivity declined between 11 and 9 ka perhaps as a result of increased summer turbidity resulting from violent storm runoff entering the lake via short, steep drainages. After 8 ka, drier, but more continental climates prevailed, and the modern diatom flora of Lake Baikal came to prominence.On Academician Ridge, a site of slow sedimentation rates, Holocene diatom assemblages at the top of 10-m cores reappear at deeper levels suggesting that such cores record at least two previous interglacial (or interstadial?) periods. Nevertheless, distinctive species that developed prior to the last glacial period indicate that the dynamics of nutrient cycling in Baikal and the responsible regional climatic environments were not entirely analogous to Holocene conditions. During

  17. Grand Lake Saint Marys, Ohio, Survey Report for Flood Control and Allied Purposes. Volume 2. Technical Appendix.

    Science.gov (United States)

    1981-08-01

    and nettle . Site 2. Adjacent to the west end of Grand Lake St. Marys between Brown and Monroe Streets, trees in the canopy in this wooded area...or in iieu of, tile drainage in attempts to combat standing water problems in affected fields. Within more recent years, an inczeasing number of farm...further reduce soil erosion since crop rotation is widely practiced to control pest insects and vary nutrient withdrawal. D-86 S . mnuu The remaining

  18. Using satellite images to monitor glacial-lake outburst floods: Lago Cachet Dos drainage, Chile

    Science.gov (United States)

    Friesen, Beverly A.; Cole, Christopher J.; Nimick, David A.; Wilson, Earl M.; Fahey, Mark J.; McGrath, Daniel J.; Leidich, Jonathan

    2015-01-01

    The U.S. Geological Survey (USGS) is monitoring and analyzing glacial-lake outburst floods (GLOFs) in the Colonia valley in the Patagonia region of southern Chile. A GLOF is a type of flood that occurs when water impounded by a glacier or a glacial moraine is released catastrophically. In the Colonia valley, GLOFs originating from Lago Cachet Dos, which is dammed by the Colonia Glacier, have recurred periodically since 2008. The water discharged during these GLOFs flows under or through the Colonia Glacier, into Lago Colonia and then the Río Colonia, and finally into the Río Baker—Chile's largest river in terms of volume of water.

  19. Chemical quality of surface waters in Devils Lake basin, North Dakota

    Science.gov (United States)

    Swenson, Herbert; Colby, Bruce R.

    1955-01-01

    fallen slowly. Hydrologic changes that may have caused Devils Lake to alter from a very large, moderately deep lake of fresh water to a small, shallow body of brackish water are discussed and evaluated on the basis of scanty information. During several years of average precipitation, temperature, and evaporation, Devils Lake and lakes upstream should receive nearly a quarter of an inch of runoff annually from the drainage area of about 3,000 square miles. Approximately 55 square miles of tributary area would be required to maintain each square mile of lake surface. However, runoff, expressed as percentage of the average, differs greatly from year to year. The amount of runoff retained in upstream lakes also Varies greatly. For these two reasons, annual inflow to Devils Lake is extremely variable. Because many waterways in this basin have no surface outlets at normal stages, runoff collects in depressions, is concentrated by evaporation, and forms saline or alkaline lakes. The chemical and physical properties of the lake waters vary chiefly with changes in lake stage and volume of inflow. Scattered records from 1899 to 1923 and more comprehensive data from 1948 to 1952 show a range of salt concentration from 6,130 to 25,000 parts per million (ppm) in the water of Devils Lake. Although concentration has varied, the chemical composition of the dissolved solids has not changed appreciably. Lake waters are more concentrated in the lower part of the basin, downstream from Devils Lake. For periods of record the salt concentration ranged from 14,932 to 62,000 ppm in East Devils Lake and from 19,000 to 106,000 ppm in east Stump Lake. Current and past tonnages of dissolved solids in Devils Lake, East Bay Devils Lake, East Devils Lake, and east and west Stump Lakes were computed from concentrations and from altitude-capacity curves for each lake. Neither the average rate of diversion of water to restore Devils Lake to a higher level nor the quality of the divert

  20. Remote Sensing and Shallow Geophysical Investigations on Moghra Lake in Northeastern Qattarra Depression, Western Desert, Egypt

    Science.gov (United States)

    Khan, S. D.; Fathy, M. S.; Azeem, M. A.

    2012-12-01

    The Western Desert of Egypt encompasses two thirds of the land area of Egypt and constitutes one of the driest regions of the Sahara. This desert has seven depressions; Siwa, Qattara, Fayium, Bahariya, Farafra, Dakhla and Kharga. These depressions may be the manifestation of old drainage basins with extensive erosion and possibly some tectonic activity. Several oases with freshwater can be found in these depressions. Geological and geophysical investigations in Qattara Depression indicate several buried fluvial channels with flow direction from highlands in southeast to northwest. Moghra Lake at the northeastern tip of Qatarra basin may be a small remnant of a larger paleo-lake including the mouth of a paleo-river. This study probed this area for presence of buried channels that may have fed the larger Moghra paleo-lake. We have used ALOS - PALSAR radar remote sensing data to identify the surface features in this region, such as channels, channel fills, and fractures. In addition, dual polarization PALSAR data (HV, HH) allowed analysis of the near surface geology and assisted in delineating areas of interest for GPR surveys. GPR data along 2D profiles were acquired using the GSSI SIR-3000 system with a 400 MHz antenna that provided images to approximately three meters in depth. All the GPS data were processed using RADAN 6.6 software. A conventional processing flow was used for data processing: The positional correction tool removed the air wave. A range-gain balanced the amplitudes and a final band-pass (50 kHz to 500 kHz) filter was applied to the data. Deconvolution was also applied for highlighting the finer details. In addition, spatial filters were used to attenuate continuous vertical noise. The migrated sections of GPR identified a major paleochannel distributary with two minor channels at the margins. The bedrock of the studied area consists of the Lower Miocene Moghra Formation (sandstone and shale intercalations). The area around the present lake is

  1. Stable isotopes, δ18O and δ2H, in the study of water balance of Lake Massoko, Tanzania: Investigation of the exchange between lake and underground water

    International Nuclear Information System (INIS)

    Bergonzini, L.; Gibert, E.; Winckel, A.

    2002-01-01

    Full text: The stable oxygen and deuterium isotope compositions of a lake depend upon its water balance. Therefore the balance equations of stable isotopes, which imply calculation of the composition of evaporating moisture α E , provide information for assessing the water balance. In most cases, this approach is used to investigate the relationships between lakes and groundwater. Lake Massoko (8 deg. 20'S, 33 deg. 45'E, 870 m.a.s.l.) is a freshwater maar-lake without surface outlet. The lake surface and its runoff area cover 0.38 and 0.55 km 2 respectively. In contrast with the mean annual rainfall in the other parts of south Tanzania (1000-1200 mm y -1 ), the presence of Lake Malawi to the South, and the high ranges to the North (Mounts Poroto, Rungwe and Livingstone) imply local climatic features. Air masses overloaded with humidity bypassing Lake Malawi are submitted, especially in April, to ascending currents, producing rainfalls up to 2450 mm y -1 over Massoko area. Because of the evaporation rate from the lake's surface (around 2100 mm y -1 ) and without taking into account the runoff from the drainage basin, hydrological balance is positive and imply underground lost. One of most difficult points in the establishment of the isotope balances is the calculation of the composition of the evaporated water (δ E ), which requires an estimation of the isotopic composition of the water vapour in the atmosphere over the lake (δ Atm ). Without direct measurements, two ways can be used for the determination of the vapour composition (i) equilibrium with precipitation and reconstitution from them, or (ii) calculation from the balances of a terminal lake of the region. Both approaches are presented and compared, but only the second one allows physical solutions. δ Atm determined from Lake Rukwa hydrological and isotope balances has been used to calculate values for δ E over Lake Massoko. The estimation of δ Atm obtained from Lake Rukwa budgets presents a deuterium

  2. An investigation of the effects of an arterial drainage scheme on the rainfall-runoff transformation behaviour of the Brosna catchment in Ireland

    Science.gov (United States)

    Bhattarai, K. P.; O'Connor, K. M.

    2003-04-01

    Inefficient natural land drainage and the consequent frequent flooding of rivers are a problem of particular significance to the Irish economy. Such problems can be attributed less to the amount of annual rainfall, than to the topological configuration of Ireland. Its high maritime rim and relatively flat interior results in poor river gradients, intercepted by many lakes. As a remedial measure to tackle these problems, Arterial Drainage Schemes (ADSs) were started in Ireland from as early as the beginning of the nineteenth century. The major activities carried out under ADSs have been the deepening and widening of channels to increase their discharge-carrying capacity, which naturally affected the hydrological behaviour of the catchments involved. Earlier studies carried out in order to assess the effects of such ADSs on the hydrological behaviour of Irish catchments were concentrated mainly on comparisons of unit hydrographs and relationship between flood peaks of pre- and post-drainage periods. The present study, carried out on the River Brosna catchment in Ireland, concentrates on assessing the changes in the rainfall runoff transformation process, by using the conceptual Soil Moisture Accounting and Routing Model (SMAR), one of the constituent models of the "Galway River Flow Modelling and Forecasting System (GFMFS)" software package. Hydro-meteorological data of the pre-drainage (1942--1947) and post-drainage (1954--2000) periods have been used in this study. The results of the present study show that, for similar patterns of rainfall, the catchment produces higher annual maximum daily flows, and lower annual minimum daily flows in the post-drainage period than in the pre-drainage period. Moreover, the post-drainage unit hydrographs are more "peaky" and have quicker recessions than the pre-drainage counterparts, thus confirming the findings of the earlier studies. It is also observed that, apart from the expected pre-to-post-drainage change, the nature of the

  3. GEOCHEMICAL AND ISOTOPIC INVESTIGATION OF LAKES IN THE TRENTO PROVINCE (ITALY

    Directory of Open Access Journals (Sweden)

    Marco Natale

    2013-09-01

    Full Text Available We present the geochemical composition and the stable isotope signature (18O/16O and 2H/1H of waters sampled from six lakes (Caldonazzo, Levico, Lases, Santa Colomba, Lamar and Santo located in the Province of Trento. The chemical compositions invariably revealed a HCO3-Ca hydrochemical facies; however slight differences were observed among the lakes, in relation to the lithologies distinguishing each lakes’drainage basin. Elemental ratios and in particular the Rb/Sr provide a discriminative tool to recognize the rocks that have been weathered; for example this ratio is high in water that interacted with volcanic ignimbrites (rhyolites, and low in rocks that interacted with carbonate rocks. Many other trace elements were analyzed, thus providing baseline data, and only arsenic displayed concentrations higher than the legislative threshold defined for drinking water (10mg/l, especially in Lake Levico (10-19 mg/l. As concerns the stable isotopes δD and δ18O, the obtained results approach the meteoric signature for waters sampled during the 2012 winter season. The waters sampled during two summers (2011 and 2012 displayed distinctive trends, reflecting the significant influence of evaporative processes. We emphasize that the annual differences recorded in the isotopic composition of distinct years are plausibly related to temperature changes and type of precipitation that recharged the lakes. In this light, the peculiar isotopic signature recorded in the year 2011 is possibly related to a significant snowy period, which greatly contributed to the lakes’ water budget. Interestingly, waters from Lake Santa Colomba were systematically different from all the other samples, possibly due to more effective evaporative processes, or to the involvement of deep underground recharge including fossil waters.

  4. Ecological Health and Water Quality Assessments in Big Creek Lake, AL

    Science.gov (United States)

    Childs, L. M.; Frey, J. W.; Jones, J. B.; Maki, A. E.; Brozen, M. W.; Malik, S.; Allain, M.; Mitchell, B.; Batina, M.; Brooks, A. O.

    2008-12-01

    Big Creek Lake (aka J.B. Converse Reservoir) serves as the water supply for the majority of residents in Mobile County, Alabama. The area surrounding the reservoir serves as a gopher tortoise mitigation bank and is protected from further development, however, impacts from previous disasters and construction have greatly impacted the Big Creek Lake area. The Escatawpa Watershed drains into the lake, and of the seven drainage streams, three have received a 303 (d) (impaired water bodies) designation in the past. In the adjacent ecosystem, the forest is experiencing major stress from drought and pine bark beetle infestations. Various agencies are using control methods such as pesticide treatment to eradicate the beetles. There are many concerns about these control methods and the run-off into the ecosystem. In addition to pesticide control methods, the Highway 98 construction projects cross the north area of the lake. The community has expressed concern about both direct and indirect impacts of these construction projects on the lake. This project addresses concerns about water quality, increasing drought in the Southeastern U.S., forest health as it relates to vegetation stress, and state and federal needs for improved assessment methods supported by remotely sensed data to determine coastal forest susceptibility to pine bark beetles. Landsat TM, ASTER, MODIS, and EO-1/ALI imagery was employed in Normalized Difference Vegetation Index (NDVI) and Normalized Difference Moisture Index (NDMI), as well as to detect concentration of suspended solids, chlorophyll and water turbidity. This study utilizes NASA Earth Observation Systems to determine how environmental conditions and human activity relate to pine tree stress and the onset of pine beetle invasion, as well as relate current water quality data to community concerns and gain a better understanding of human impacts upon water resources.

  5. Percutaneous catheter drainage of tuberculous psoas abscesses

    International Nuclear Information System (INIS)

    Pombo, F.; Martin-Egana, R.; Cela, A.; Diaz, J.L.; Linares-Mondejar, P.; Freire, M.

    1993-01-01

    Six patients with 7 tuberculous psoas or ilio-psoas abscesses were treated by CT-guided catheter drainage and chemotherapy. The abscesses (5 unilateral and 1 bilateral) were completely drained using a posterior or lateral approach. The abscess volume was 70 to 700 ml (mean 300 ml) and the duration of drainage 5 to 11 days (mean 7 days). Immediate local symptomatic improvement was achieved in all patients, and there were no procedural complications. CT follow-up at 3 to 9 months showed normalization in 5 patients, 2 of whom are still in medical therapy. One patient, who did not take the medication regularly, had a recurrent abscess requiring new catheter drainage after which the fluid collection disappeared. Percutaneous drainage represents an efficient and attractive alternative to surgical drainage as a supplement to medical therapy in the management of patients with large tuberculous psoas abscesses. (orig.)

  6. Definition of the drainage filter problem

    NARCIS (Netherlands)

    Zaslavsky, D.

    1977-01-01

    It is common to consider the following: I. Retention of soil particles that may enter the drainage pipe and cause its clogging. For some sensitive structures it is important to prevent settlements due to soil transportation by drainage water.

  7. Effects of Accelerated Deglaciation on Chemical Characteristics of Sub-arctic Lakes and Rivers in South and West Iceland

    Science.gov (United States)

    Ritter, M.; Strock, K.; Edwards, B. R.

    2017-12-01

    Glaciers and their associated paraglacial landscapes have changed rapidly over the past century, and may see increased rates of melt as temperatures increase in high latitude environments. As glaciers recede, glacial meltwater subsidies increase to inland freshwater systems, influencing their structure and function. Evidence suggests melting ice influences the chemical characteristics of systems by providing nutrient subsidies, while inputs of glacial flour influence their physical structure by affecting temperature, reducing water clarity and increasing turbidity. Together, changes in physical and chemical structure of these systems have subsequent effects on biota, with the potential to lower taxonomic richness. This study characterized the chemistry of rivers and lakes fed by glacial meltwater in sub-arctic environments of Iceland, where there is limited limnological data. The survey characterized nutrient chemistry, dissolved organic carbon, and ion chemistry. We surveyed glacial meltwater from six glaciers in south and west Iceland, using the drainage basin of Gigjökull glacier along the southern coast as a detailed study area to examine the interactions between groundwater and surface runoff. The southern systems, within the Eastern Volcanic Zone, have minimal soil development and active volcanoes produce ash input to lakes. Lakes in the Western Volcanic Zone were more diverse, located in older bedrock with more extensively weathered soil. Key differences were observed between aquatic environments subsidized with glacial meltwater and those without. This included physical effects, such as lower temperatures and chemical effects such as lower conductivity and higher pH in glacially fed systems. In the drainage basin of Gigjökull glacier, lakes formed after the former lagoon was emptied and then partly refilled with debris from jokulhlaups during the 2010 Eyjafjallajökull eruption. These newly formed lakes resembled non-glacial melt systems despite receiving

  8. Solid Cattle Manure Less Prone to Phosphorus Loss in Tile Drainage Water.

    Science.gov (United States)

    Wang, Y T; Zhang, T Q; Tan, C S; Qi, Z M; Welacky, T

    2018-03-01

    Forms (e.g., liquid and solid) of manure influence the risk of P loss after land application. The objective of this study was to investigate the effects of P-based application of various forms of cattle manure (liquid, LCM; or solid, SCM) or inorganic P as triple superphosphate (IP) on soil P losses in tile drainage water. A 4-yr field experiment was conducted in a clay loam soil with a corn ( L.)-soybean [ (L.) Merr.] rotation in the Lake Erie basin. Over the 4 yr, the dissolved reactive P (DRP) flow-weighted mean concentration (FWMC) in tile drainage water was greater under SCM fertilization than under either IP or LCM fertilization. Despite its lower value on an annual basis, DRP FWMC rose dramatically immediately after LCM application. However, the differences in DRP FWMC did not result in detectable differences in DRP loads. Regarding particulate P and total P losses during the 4 yr, they were 68 and 47%, respectively, lower in the soils amended with SCM than in those with IP, whereas both values were similar between IP and LCM treatments. Overall, the P contained in solid cattle manure was less prone to P loss after land application. Accordingly, the present results can provide a basis for manure storage and application of best management practices designed to reduce P losses and improve crop growth. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  9. Sanctuaries for lake trout in the Great Lakes

    Science.gov (United States)

    Stanley, Jon G.; Eshenroder, Randy L.; Hartman, Wilbur L.

    1987-01-01

    Populations of lake trout, severely depleted in Lake Superior and virtually extirpated from the other Great Lakes because of sea lamprey predation and intense fishing, are now maintained by annual plantings of hatchery-reared fish in Lakes Michigan, Huron, and Ontario and parts of Lake Superior. The extensive coastal areas of the Great Lakes and proximity to large populations resulted in fishing pressure on planted lake trout heavy enough to push annual mortality associated with sport and commercial fisheries well above the critical level needed to reestablish self-sustaining stocks. The interagency, international program for rehabilitating lake trout includes controlling sea lamprey abundance, stocking hatchery-reared lake trout, managing the catch, and establishing sanctuaries where harvest is prohibited. Three lake trout sanctuaries have been established in Lake Michigan: the Fox Island Sanctuary of 121, 500 ha, in the Chippewa-Ottawa Treaty fishing zone in the northern region of the lake; the Milwaukee Reef Sanctuary of 160, 000 ha in midlake, in boundary waters of Michigan and Wisconsin; and Julian's Reef Sanctuary of 6, 500 ha, in Illinois waters. In northern Lake Huron, Drummond Island Sanctuary of 55, 000 ha is two thirds in Indian treaty-ceded waters in Michigan and one third in Ontario waters of Canada. A second sanctuary, Six Fathom Bank-Yankee Reef Sanctuary, in central Lake Huron contains 168, 000 ha. Sanctuary status for the Canadian areas remains to be approved by the Provincial government. In Lake Superior, sanctuaries protect the spawning grounds of Gull Island Shoal (70, 000 ha) and Devils Island Shoal (44, 000 ha) in Wisconsin's Apostle Island area. These seven sanctuaries, established by the several States and agreed upon by the States, Indian tribes, the U.S. Department of the Interior, and the Province of Ontario, contribute toward solving an interjurisdictional fishery problem.

  10. Subsurface drainage

    CSIR Research Space (South Africa)

    Van Der

    1993-09-01

    Full Text Available and long term behavior were evaluated. Laboratory tests for geotextile selection are recommended and tentative criteria given. The use of fin drains was evaluated in the laboratory and a field study to monitor the efficacy of drainage systems was started...

  11. Distribution and interannual variability of supraglacial lakes on debris-covered glaciers in the Khan Tengri-Tumor Mountains, Central Asia

    International Nuclear Information System (INIS)

    Qiao, Liu; Mayer, Christoph; Liu, Shiyin

    2015-01-01

    Supraglacial lakes are widely formed on debris-covered glaciers in the Khan Tengri-Tumor Mountains (KTTM), Tianshan, Central Asia. Study of their distribution characters based on regional-wide remote sensing investigations is still lacking, but it can promote our understanding about the influence of supraglacial lakes on the surface melting, hydrology and dynamics of debris-covered glaciers in this region. This study presents results of the supraglacial lake inventory in the KTTM region, based on multi-year Landsat images. We focus on the glacio-geomorphological characters of the supraglacial lakes and their late summer conditions, since all suitable Landsat images were acquired between August and September during 1990–2011. With a minimum threshold extent of 3600 m 2 for conservative mapping results, we totally mapped 775 supraglacial lakes and 38 marginal glacial lakes on eight huge debris-covered glaciers. Supraglacial lakes are concentrated on the Tumor Glacier and the South Inylchek Glacier, two biggest glaciers in this region. Although most supraglacial lakes are short-lived, a number of lakes can be repeatedly identified between different Landsat images. Detailed investigation of these ‘perennial’ lakes on the Tumor Glacier indicates that their filling frequency and area contributions have increased since 2005. Analysis of the area-elevation distributions for all mapped supraglacial lakes shows that they predominantly occur close to the altitude of 3250 m a.s.l., as high as the lowest reach of clean ice where surface debris begins to appear, and can further develop upglacier to a limit of about 3950 m a.s.l.. Total and mean area of supraglacial lakes in the KTTM region during the late summer seasons show great variability between years. Correlation analysis between the annual lake area and the observed nearby meteorological conditions suggests that warmer springs seem related to the draining of some supraglacial lakes during the following seasons, due

  12. Bacterial and toxic pollutants in lakes of river Indus

    International Nuclear Information System (INIS)

    Shafiq, H.B.; Rasool, S.A.; Ajaz, M.

    2011-01-01

    Indus river water gets polluted through three sources viz., municipal wastewater, industrial wastewater and agricultural runoff through drainage structure. The lakes in Sindh (fed by the river Indus), constitute the important source of drinking water, recreation and fish, etc. and offer employment for many. A large number of chemicals that either exist naturally in the land dissolve in the water, or human excreta added due to human activity thereby, contaminating and leading to various diseases. In order to assess the microbial contamination, detection of pollutant indicator organisms (coliform group), using Coliform test was performed by Most Probable Number technique and total bacterial count by Pour Plate method. The level of various heavy metals (arsenic, calcium, cadmium, chromium, copper, iron, lead, mercury, potassium, magnesium, manganese, sodium, selenium and zinc) and electrolytes (Cl/sup -1/, HCO/sub 3/sup -1/) was monitored in water and fish meat samples collected from Haleji and Keenjhar lakes to assess the impact of toxic pollutants. Metal concentrations in water and fish samples were estimated by atomic absorption spectrophotometry. Total coliform organisms were found in both the lake water samples, exceeded in 38% samples than the acceptable limits, while total average aerobic bacterial count analyzed in both the lakes was 102 CFU/ml - 1010 CFU/ml. Toxic chemical contaminants were estimated below the detection limit, while other several (essential) metal ions were found within the range set by WHO, except arsenic, cadmium and iron that exceeded slightly in 12.5% water samples. This study was designed to ensure the access of safe and potable water to urban and rural areas of Sindh. Further, the findings will help public/private enterprises and public health institutions to work for the people health friendly policies. (author)

  13. Endoscopic ultrasound-guided transmural drainage of postoperative pancreatic collections.

    Science.gov (United States)

    Tilara, Amy; Gerdes, Hans; Allen, Peter; Jarnagin, William; Kingham, Peter; Fong, Yuman; DeMatteo, Ronald; D'Angelica, Michael; Schattner, Mark

    2014-01-01

    Pancreatic leak is a major cause of morbidity after pancreatectomy. Traditionally, peripancreatic fluid collections have been managed by percutaneous or operative drainage. Data for endoscopic ultrasound (EUS)-guided drainage of postoperative fluid collections are limited. Here we report on the safety, efficacy, and timing of EUS-guided drainage of postoperative peripancreatic collections. This is a retrospective review of 31 patients who underwent EUS-guided drainage of fluid collections after pancreatic resection. Technical success was defined as successful transgastric deployment of at least one double pigtail plastic stent. Clinical success was defined as resolution of the fluid collection on follow-up CT scan and resolution of symptoms. Early drainage was defined as initial transmural stent placement within 30 days after surgery. Endoscopic ultrasound-guided drainage was performed effectively with a technical success rate of 100%. Clinical success was achieved in 29 of 31 patients (93%). Nineteen of the 29 patients (65%) had complete resolution of their symptoms and collection with the first endoscopic procedure. Repeat drainage procedures, including some with necrosectomy, were required in the remaining 10 patients, with eventual resolution of collection and symptoms. Two patients who did not achieve durable clinical success required percutaneous drainage by interventional radiology. Seventeen (55%) of 31 patients had successful early drainage completed within 30 days of their operation. Endoscopic ultrasound-guided drainage of fluid collections after pancreatic resection is safe and effective. Early drainage (collections was not associated with increased complications in this series. Copyright © 2014 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Climate change induced salinisation of artificial lakes in the Netherlands and consequences for drinking water production.

    Science.gov (United States)

    Bonte, Matthijs; Zwolsman, John J G

    2010-08-01

    In this paper we present a modelling study to investigate the impacts of climate change on the chloride concentration and salinisation processes in two man-made freshwater lakes in the Netherlands, Lake IJsselmeer and Lake Markermeer. We used a transient compartmental chloride and water balance model to elucidate the salinisation processes occurring under present conditions and assess future salinisation under two climate forcing scenarios. The model results showed that the Rhine River is the dominant determinant for the chloride concentration in both lakes, followed by drainage of brackish groundwater from the surrounding polders. The results further show that especially during dry years, seawater intrusion through the tidal closure dam is an important source of chloride to Lake IJsselmeer. The results from the climatic forcing scenarios show that Lake IJsselmeer is especially vulnerable to climate-induced salinisation whereas effects on Lake Markermeer are relatively small. Peak chloride concentrations at the raw water intake of the Andijk drinking water facility on Lake IJsselmeer are projected to increase to values above 250 mg/l in the most far-reaching climate change scenario W+ in 2050 for dry years. This is well above the maximum allowable concentration of 150 mg/l for chloride in drinking water. Modelling showed that climate change impacts the chloride concentrations in a variety of ways: 1) an increasing occurrence of low river flows from summer to autumn reduces the dilution of the chloride that is emitted to the Rhine with a constant load thereby increasing its concentration; 2) increased open water evaporation and reduced rainfall during summer periods and droughts increases the chloride concentration in the water; and 3) rises in sea level increase seawater intrusion through the tidal closure dam of Lake IJsselmeer. The processes described here are likely to affect many other tidal rivers or lakes and should be considered when planning future raw

  15. Thoracoscopic Surgery for Pneumothorax Following Outpatient Drainage Therapy.

    Science.gov (United States)

    Sano, Atsushi; Yotsumoto, Takuma

    2017-10-20

    We investigated the outcomes of surgery for pneumothorax following outpatient drainage therapy. We reviewed the records of 34 patients who underwent operations following outpatient drainage therapy with the Thoracic Vent at our hospital between December 2012 and September 2016. Indications for outpatient drainage therapy were pneumothorax without circulatory or respiratory failure and pleural effusion. Indications for surgical treatment were persistent air leakage and patient preference for surgery to prevent or reduce the incidence of recurrent pneumothorax. Intraoperatively, 9 of 34 cases showed loose adhesions around the Thoracic Vent, all of which were dissected bluntly. The preoperative drainage duration ranged from 5 to 13 days in patients with adhesions and from 3 to 19 days in those without adhesions, indicating no significant difference. The duration of preoperative drainage did not affect the incidence of adhesions. The operative duration ranged from 30 to 96 minutes in patients with adhesions and from 31 to 139 minutes in those without adhesions, also indicating no significant difference. Outpatient drainage therapy with the Thoracic Vent was useful for spontaneous pneumothorax patients who underwent surgery, and drainage for less than 3 weeks did not affect intraoperative or postoperative outcomes.

  16. Foamed emulsion drainage: flow and trapping of drops

    OpenAIRE

    Schneider, Maxime; Zou, Ziqiang; Langevin, Dominique; Salonen, Anniina

    2017-01-01

    Foamed emulsions are ubiquitous in our daily life but the ageing of such systems is still poorly understood. In this study we investigate foam drainage and measure the evolution of the gas, liquid and oil volume fractions inside the foam. We evidence three regimes of ageing. During an initial period of fast drainage, both bubbles and drops are very mobile. As the foam stabilises drainage proceeds leading to a gradual decrease of the liquid fraction and slowing down of drainage. Clusters of oi...

  17. Preoperative endoscopic versus percutaneous transhepatic biliary drainage in potentially resectable perihilar cholangiocarcinoma (DRAINAGE trial): design and rationale of a randomized controlled trial

    OpenAIRE

    Wiggers, Jimme K; Coelen, Robert JS; Rauws, Erik AJ; van Delden, Otto M; van Eijck, Casper HJ; de Jonge, Jeroen; Porte, Robert J; Buis, Carlijn I; Dejong, Cornelis HC; Molenaar, I Quintus; Besselink, Marc GH; Busch, Olivier RC; Dijkgraaf, Marcel GW; van Gulik, Thomas M

    2015-01-01

    Background Liver surgery in perihilar cholangiocarcinoma (PHC) is associated with high postoperative morbidity because the tumor typically causes biliary obstruction. Preoperative biliary drainage is used to create a safer environment prior to liver surgery, but biliary drainage may be harmful when severe drainage-related complications deteriorate the patients? condition or increase the risk of postoperative morbidity. Biliary drainage can cause cholangitis/cholecystitis, pancreatitis, hemorr...

  18. Percutaneous drainage treatment of primary liver abscesses

    Energy Technology Data Exchange (ETDEWEB)

    Berger, H.; Pratschke, E.; Berr, F.; Fink, U.

    1989-02-01

    28 primary liver abscesses, including 9 amoebic abscesses, in 24 patients were drained percutaneously. Indication for drainage in amoebic abscesses was imminent rupture and clinical symptoms as pleural effusion, lung atelectasis and pain. 95% of the primary abscesses were cured by percutaneous drainage and systemic antibiotic treatment. There was one recurrence of abscess, which was managed surgically. Reasons for drainage failure were: tumour necrosis and tumour perforation with secondary liver abscess.

  19. Radiologic drainage of infected and noninfected thoracic fluid collections

    International Nuclear Information System (INIS)

    Van Sonnenberg, E.; Casola, G.; Stavas, J.; Neff, C.C.; Varney, R.A.; Wittich, G.R.; Dillard, J.; Christensen, R.A.; Friedman, P.J.

    1987-01-01

    Radiologically guided drainage of 100 thoracic fluid collections is described in this paper. Collections that underwent drainage include empyemas, lung abscesses, bronchopleural fistulas (BPFs), mediastinal abscesses, paracardial collections, bronchogenic cysts, sequestrations, lymphoceles, lymphangiomas, malignant effusions, and necrotic tumors. Catheters were placed for sclerotherapy in nine patients. Guidance modalities (in descending order of frequency) were CT, US, fluoroscopy, and MR. Inadequate thoracostomy tube drainage occurred in a third of the patients prior to radiologic drainage. Drainages were effective in 85% of cases, sparing surgery or another thoracostomy tube. Complications occurred in 7% of patients, most being minor and none requiring operation. Criteria for drainage of lung abscess and BPF will be emphasized, as will techniques and methods of follow-up

  20. Tile Drainage Expansion Detection using Satellite Soil Moisture Dynamics

    Science.gov (United States)

    Jacobs, J. M.; Cho, E.; Jia, X.

    2017-12-01

    In the past two decades, tile drainage installation has accelerated throughout the Red River of the North Basin (RRB) in parts of western Minnesota, eastern North Dakota, and a small area of northeastern South Dakota, because the flat topography and low-permeability soils in this region necessitated the removal of excess water to improve crop production. Interestingly, streamflow in the Red River has markedly increased and six of 13 major floods during the past century have occurred since the late 1990s. It has been suggested that the increase in RRB flooding could be due to change in agricultural practices, including extensive tile drainage installation. Reliable information on existing and future tile drainage installation is greatly needed to capture the rapid extension of tile drainage systems and to locate tile drainage systems in the north central U.S. including the RRB region. However, there are few reliable data of tile drainage installation records, except tile drainage permit records in the Bois de Sioux watershed (a sub-basin in southern part of the RRB where permits are required for tile drainage installation). This study presents a tile drainage expansion detection method based on a physical principle that the soil-drying rate may increase with increasing tile drainage for a given area. In order to capture the rate of change in soil drying rate with time over entire RRB (101,500 km2), two satellite-based microwave soil moisture records from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) and AMSR2 were used during 2002 to 2016. In this study, a sub-watershed level (HUC10) potential tile drainage growth map was developed and the results show good agreement with tile drainage permit records of six sub-watersheds in the Bois de Sioux watershed. Future analyses will include improvement of the potential tile drainage map through additional information using optical- and thermal-based sensor products and evaluation of its

  1. Evolution of alkaline lakes - Lake Van case study

    Science.gov (United States)

    Tillman Meyer, Felix; Viehberg, Finn; Bahroun, Sonya; Wolf, Annabel; Immenhauser, Adrian; Kwiecien, Ola

    2017-04-01

    Lake Van in Eastern Anatolia (Turkey) is the largest terminal soda lake on Earth. The lake sedimentary profile covers ca. 600 ka (Stockhecke et al. 2014) Based on lithological changes, the presence of freshwater microfossils and close-to-freshwater pH value in the pore water, members of ICDP PALEOVAN concluded that Lake Van might have started as an open lake. Here we show paleontological and geochemical evidence in favour of this idea and constrain the time, when Lake Van likely transformed into a closed lake. Additionally we provide the first conceptual model of how this closure may have happened. Our archives of choice are inorganic and biogenic carbonates, separated by wet sieving. We identified microfossil assemblages (fraction > 125 µm) and performed high-resolution oxygen isotope (delta18O) and elemental (Mg/Ca, Sr/Ca) analyses of the fraction plants growing in the photic zone as food supply. These two aspects point to an increasing salinity in a shallowing lake. The delta18O values of inorganic carbonates are relatively low during the initial phase of Lake Van and increase abruptly (ca. 7‰) after 530 ka BP. At approximately the same time combination of Sr/Ca and Mg/Ca data suggest first occurrence of aragonite. Again, these findings suggest geochemical changes of the lake water concurrent with transition documented by microfossils. Comparison between Lake Van and Lake Ohrid (Lacey et al. 2016) delta18O data, precludes regional climate change (e.g.: increased evaporation) as the main driver of observed changes. With no evidence for increased volcanic or tectonic activity (e.g.: tephra layers, deformation structures, slumping) in the Lake Van sedimentary profile around 530 ka, it seems unlikely that a pyroclastic flow blocked the outflow of the lake. Alternatively, a portion of inflow has been diverged which might have caused a change in the hydrological balance and lake level falling below its outlet. However, as no geomorphological data confirming this

  2. Bundle of measures for external cerebral ventricular drainage-associated ventriculitis.

    Science.gov (United States)

    Chatzi, Maria; Karvouniaris, Marios; Makris, Demosthenes; Tsimitrea, Eleni; Gatos, Charalampos; Tasiou, Anastasia; Mantzarlis, Kostas; Fountas, Kostas N; Zakynthinos, Epaminondas

    2014-01-01

    To assess the prevalence and outcome of external cerebral ventricular drainage-associated ventriculitis in neurocritical patients before and after the implementation of a bundle of external cerebral ventricular drainage-associated ventriculitis control measures. Clinical prospective case series. University Hospital of Larissa, Greece. Consecutive patients were recruited from the ICU of the hospital. Patient inclusion criteria included presence of external ventricular drainage and ICU stay more than 48 hours. The bundle of external cerebral ventricular drainage-associated ventriculitis control measures included 1) reeducation of ICU personnel on issues of infection control related to external cerebral ventricular drainage, 2) meticulous intraventricular catheter handling, 3) cerebrospinal fluid sampling only when clinically necessary, and 4) routine replacement of the drainage catheter on the seventh drainage day if the catheter was still necessary. The bundle was applied after an initial period (preintervention) where standard policy for external cerebral ventricular drainage-associated ventriculitis was established. External cerebral ventricular drainage-associated ventriculitis prevalence, external cerebral ventricular drainage-associated ventriculitis events per 1,000 drainage days (drain-associated infection rate), length of ICU stay, Glasgow Outcome Scale at 6 months, and risk factors for external cerebral ventricular drainage-associated ventriculitis. Eighty-two patients entered the study in the preintervention period and 57 patients during the intervention period. During the preintervention and intervention period, external cerebral ventricular drainage-associated ventriculitis prevalence was 28% and 10.5% (p = 0.02) and drain-associated infection rate was 18 and 7.1, respectively (p = 0.0001); mean (95% CI) length of ICU stay in patients who presented external cerebral ventricular drainage-associated ventriculitis was 44.4 days (36.4-52.4 d), whereas mean

  3. Bathymetry of Lake Erie and Lake Saint Clair

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Erie and Lake Saint Clair has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and...

  4. Percutaneous drainage treatment of primary liver abscesses

    International Nuclear Information System (INIS)

    Berger, H.; Pratschke, E.; Berr, F.; Fink, U.; Klinikum Grosshadern, Muenchen; Klinikum Grosshadern, Muenchen

    1989-01-01

    28 primary liver abscesses, including 9 amoebic abscesses, in 24 patients were drained percutaneously. Indication for drainage in amoebic abscesses was imminent rupture and clinical symptoms as pleural effusion, lung atelectasis and pain. 95% of the primary abscesses were cured by percutaneous drainage and systemic antibiotic treatment. There was one recurrence of abscess, which was managed surgically. Reasons for drainage failure were: tumour necrosis and tumour perforation with secondary liver abscess. (orig.) [de

  5. Endoscopic Ultrasound-Guided Biliary Drainage

    International Nuclear Information System (INIS)

    Artifon, Everson L.A.; Ferreira, Fla'vio C.; Sakai, Paulo

    2012-01-01

    To demonstrate a comprehensive review of published articles regarding endoscopic ultrasound (EUS)-guided biliary drainage. Review of studies regarding EUS-guided biliary drainage including case reports, case series and previous reviews. EUS-guided hepaticogastrostomy, coledochoduodenostomy and choledoantrostomy are advanced biliary and pancreatic endoscopy procedures, and together make up the echo-guided biliary drainage. Hepaticogastrostomy is indicated in cases of hilar obstruction, while the procedure of choice is the coledochoduodenostomy or choledochoantrostomy in distal lesions. Both procedures must be performed only after unsuccessful ERCPs. The indication of these procedures must be made under a multidisciplinary view while sharing information with the patient or legal guardian. Hepaticogastrostomy and coledochoduodenostomy or choledochoantrostomy are feasible when performed by endoscopists with expertise in biliopancreatic endoscopy. Advanced echo-endoscopy should currently be performed under a rigorous protocol in educational institutions.

  6. Endoscopic Ultrasound-Guided Biliary Drainage

    Energy Technology Data Exchange (ETDEWEB)

    Artifon, Everson L.A.; Ferreira, Fla& #x27; vio C.; Sakai, Paulo [University of Saeo Paulo, Saeo Paulo (Brazil)

    2012-02-15

    To demonstrate a comprehensive review of published articles regarding endoscopic ultrasound (EUS)-guided biliary drainage. Review of studies regarding EUS-guided biliary drainage including case reports, case series and previous reviews. EUS-guided hepaticogastrostomy, coledochoduodenostomy and choledoantrostomy are advanced biliary and pancreatic endoscopy procedures, and together make up the echo-guided biliary drainage. Hepaticogastrostomy is indicated in cases of hilar obstruction, while the procedure of choice is the coledochoduodenostomy or choledochoantrostomy in distal lesions. Both procedures must be performed only after unsuccessful ERCPs. The indication of these procedures must be made under a multidisciplinary view while sharing information with the patient or legal guardian. Hepaticogastrostomy and coledochoduodenostomy or choledochoantrostomy are feasible when performed by endoscopists with expertise in biliopancreatic endoscopy. Advanced echo-endoscopy should currently be performed under a rigorous protocol in educational institutions.

  7. Predictors of chest drainage complications in trauma patients

    Directory of Open Access Journals (Sweden)

    CECÍLIA ARAÚJO MENDES

    2018-04-01

    Full Text Available ABSTRACT Objective: to identify predictors of chest drainage complications in trauma patients attended at a University Hospital. Methods: we conducted a retrospective study of 68 patients submitted to thoracic drainage after trauma, in a one-year period. We analyzed gender, age, trauma mechanism, trauma indices, thoracic and associated lesions, environment in which the procedure was performed, drainage time, experience of the performer, complications and evolution. Results: the mean age of the patients was 35 years and the male gender was the most prevalent (89%. Blunt trauma was the most frequent, with 67% of cases, and of these, 50% were due to traffic accidents. The mean TRISS (Trauma and Injury Severity Score was 98, with a mortality rate of 1.4%. The most frequent thoracic and associated lesions were, respectively, rib fractures (51% and abdominal trauma (32%. The mean drainage time was 6.93 days, being higher in patients under mechanical ventilation (p=0.0163. The complication rate was 26.5%, mainly poor drain positioning (11.77%. Hospital drainage was performed in 89% of cases by doctors in the first year of specialization. Thoracic drainage performed in prehospital care presented nine times more chances of complications (p=0.0015. Conclusion: the predictors of post-trauma complications for chest drainage were a procedure performed in an adverse site and mechanical ventilation. The high rate of complications demonstrates the importance of protocols of care with the thoracic drainage.

  8. Natural attenuation of antimony in mine drainage water

    International Nuclear Information System (INIS)

    Manaka, Mitsuo; Yanase, Nobuyuki; Sato, Tsutomu; Fukushi, Keisuke

    2007-01-01

    In this study, we investigated the natural attenuation of antimony (Sb) in the drainage water of an abandoned mine. Drainage water, waste rocks, and ocherous precipitates collected from the mine were investigated in terms of their mineralogy and chemistry. The chemistry of the drainage water was analyzed by measuring pH, oxidation-reduction potential (ORP), and electric conductivity on site as well as by inductively coupled plasma mass spectrometry and ion chromatography. As the drainage flowed downstream, the pH decreased rapidly from 7.05 to 3.26 and then increased slowly to 3.50. In a section where the pH increased, ocherous precipitates occur on a drainage water channel. We determined Sb levels in the drainage water, and the distribution of Sb in the mineral phases of waste rocks and precipitates was estimated by means of a sequential extraction procedure. The results of these investigations indicated that Sb, which is generated by the dissolution of stibnite (Sb 2 S 3 ) and secondary formed Sb minerals in waste rocks, was attenuated by iron-bearing ocherous precipitates, especially schwertmannite, that form over time in the drainage water. The Sb concentrations in the ocherous precipitates were up to 370 mg/kg, whereas the Sb concentrations in the drainage water downstream were below background levels (0.6 μg/L). Bulk distribution coefficients (K d ) for this Sb adsorption to the precipitates ranges up to at least 10 5 L/kg. (author)

  9. adequacy of drainage channels f drainage channels in a small

    African Journals Online (AJOL)

    eobe

    The area upon which waterfalls and the netw through ... ls were determined using the rational model and manning's equation. A .... runoff, including roads, culverts and drainage systems. ... hence, detailed design information of the drain is.

  10. High-resolution lake sediment reconstruction of industrial impact in a world-class mining and smelting center, Sudbury, Ontario, Canada

    International Nuclear Information System (INIS)

    Schindler, Michael; Kamber, Balz S.

    2013-01-01

    Highlights: • High-resolution sampling of a lake-sediment core. • Resolution of historical events in a smelter-impacted area. • Perturbation of Cu and Ni in a sediment core. • Fingerprinting sediments and pollutants using Pb isotopes and trace elements. - Abstract: A lake sediment core from Vermillion Lake, Sudbury, Ontario was tightly sampled and analyzed for a wide range of trace elements as well as for Pb isotopes. The data resolve multiple historical events in the 140-a history of logging and mining in the Sudbury area in unprecedented detail. Lead-210 data, 137 Cs activity and historical information on the start of anthropogenic activities in the Sudbury area were combined to derive an age model for the sedimentary column. Using the age information, it is possible to identify sediment sections enriched and depleted in trace metal(loid)s, particularly Ni and Cu, the two most relevant metals in the Sudbury area. Maxima and minima in the chronology of Ni and Cu coincide well with local production values for both elements until environmental regulations in the 1990s resulted in a decrease in their emission and drainage into Vermillion Lake. Differences in the deposition rates of Ni and Cu, trace-metal distribution patterns throughout the sedimentary column, Pb-isotope data, and comparison with data for local rocks and ores in the Sudbury area were used to identify the sources of pollutants in the early and late periods of mining activities. In addition, the environmental impact on the sediment itself was also studied via the variation of water content and organic matter. Finally, a surficial Fe–Mn-enriched layer with elevated concentrations of the oxy-anions (PO 4 ) 3− , (AsO 4 ) 4− , and (MoO 4 ) 2− was identified. This can be distinguished from accumulation of Zn and an increase in the Y / Ho ratio in the upper core sections, which likely imply increasing drainage of fertilizers into the Vermillion River watershed. The chemistry, mineralogy, and

  11. Tilting of Lake Pielinen, eastern Finland – an example of extreme transgressions and regressions caused by differential post-glacial isostatic uplift

    Directory of Open Access Journals (Sweden)

    Heikki Seppä

    2012-08-01

    Full Text Available Tilting of large lakes due to differential isostatic uplift in the glaciated regions of the Northern Hemisphere is a well-documented process. With the help of accurate digital elevation models and spatial GIS analysis techniques, the resulting hydro­logical changes, including shifts in the outlets and changes in the size and configuration of lakes, can now be mapped and calculated more precisely than before. As a case study to highlight the magnitude of such changes in Fennoscandia, we investigated and reinterpreted the Holocene palaeogeography and palaeohydrology of Lake Pielinen in eastern Finland. This lake is currently 99 km long and located parallel to the direction of land uplift, being thus particularly sensitive to the impacts of tilting. Our results show that the lake was formed at the end of the regional deglaciation, following drainage of a local ice-dammed lake. In its initial stage until 10 200 cal yr BP, the outlet of the newly-formed lake was located in its northwestern end, but the tilting led to a major water level transgression in the basin, eventually causing formation of a new outlet over the southeastern threshold. The lake area was 143 km long and its area was 1998 km2 at the time of formation of the southeastern outlet at 10 200 cal yr BP. The lake level has been regressive throughout the basin during the last 10 200 years. This regression will continue for approximately another 10 000 years until all the glacial isostatic adjustment has occurred, after which Lake Pielinen will be only 89 km long and 565 km2 in area.

  12. Experimental and numerical analysis of the drainage of aluminium foams

    International Nuclear Information System (INIS)

    Brunke, O; Hamann, A; Cox, S J; Odenbach, S

    2005-01-01

    Drainage is one of the driving forces for the temporal instability of molten metal foams. For usual aqueous foams this phenomenon is well examined and understood on both the experimental and the theoretical side. The situation is different for metallic foams. Due to their opaque nature, the observation of drainage is only possible by either measuring the density distribution of solidified samples ex situ or by x-ray or neutron radioscopy. Up to now there exists just one theoretical study describing the drainage behaviour of metallic foams incorporating the drainage equation, the temperature dependence of the viscosity and thermal transport. This paper will present results on the drainage behaviour of aluminium foams grown by a powder-metallurgical production route. For this purpose an experiment which allows the observation of drainage in cylindrical metal foam columns has been developed. Experimental density profiles after different drainage times are measured ex situ and compared to numerical results of the standard drainage equation for aqueous foams. This first comparison between the density redistribution of metallic aluminium foams and numerical solutions shows that the standard drainage equation can be used to explain the drainage behaviour of metallic foams

  13. Geochemical characterisation of seepage and drainage water quality from two sulphide mine tailings impoundments: Acid mine drainage versus neutral mine drainage

    Science.gov (United States)

    Heikkinen, P.M.; Raisanen, M.L.; Johnson, R.H.

    2009-01-01

    Seepage water and drainage water geochemistry (pH, EC, O2, redox, alkalinity, dissolved cations and trace metals, major anions, total element concentrations) were studied at two active sulphide mine tailings impoundments in Finland (the Hitura Ni mine and Luikonlahti Cu mine/talc processing plant). The data were used to assess the factors influencing tailings seepage quality and to identify constraints for water treatment. Changes in seepage water quality after equilibration with atmospheric conditions were evaluated based on geochemical modelling. At Luikonlahti, annual and seasonal changes were also studied. Seepage quality was largely influenced by the tailings mineralogy, and the serpentine-rich, low sulphide Hitura tailings produced neutral mine drainage with high Ni. In contrast, drainage from the high sulphide, multi-metal tailings of Luikonlahti represented typical acid mine drainage with elevated contents of Zn, Ni, Cu, and Co. Other factors affecting the seepage quality included weathering of the tailings along the seepage flow path, process water input, local hydrological settings, and structural changes in the tailings impoundment. Geochemical modelling showed that pH increased and some heavy metals were adsorbed to Fe precipitates after net alkaline waters equilibrated with the atmosphere. In the net acidic waters, pH decreased and no adsorption occurred. A combination of aerobic and anaerobic treatments is proposed for Hitura seepages to decrease the sulphate and metal loading. For Luikonlahti, prolonged monitoring of the seepage quality is suggested instead of treatment, since the water quality is still adjusting to recent modifications to the tailings impoundment.

  14. Lake whitefish diet, condition, and energy density in Lake Champlain and the lower four Great Lakes following dreissenid invasions

    Science.gov (United States)

    Herbst, Seth J.; Marsden, J. Ellen; Lantry, Brian F.

    2013-01-01

    Lake Whitefish Coregonus clupeaformis support some of the most valuable commercial freshwater fisheries in North America. Recent growth and condition decreases in Lake Whitefish populations in the Great Lakes have been attributed to the invasion of the dreissenid mussels, zebra mussels Dreissena polymorpha and quagga mussels D. bugensis, and the subsequent collapse of the amphipod, Diporeia, a once-abundant high energy prey source. Since 1993, Lake Champlain has also experienced the invasion and proliferation of zebra mussels, but in contrast to the Great Lakes, Diporeia were not historically abundant. We compared the diet, condition, and energy density of Lake Whitefish from Lake Champlain after the dreissenid mussel invasion to values for those of Lake Whitefish from Lakes Michigan, Huron, Erie, and Ontario. Lake Whitefish were collected using gill nets and bottom trawls, and their diets were quantified seasonally. Condition was estimated using Fulton's condition factor (K) and by determining energy density. In contrast to Lake Whitefish from some of the Great Lakes, those from Lake Champlain Lake Whitefish did not show a dietary shift towards dreissenid mussels, but instead fed primarily on fish eggs in spring, Mysis diluviana in summer, and gastropods and sphaeriids in fall and winter. Along with these dietary differences, the condition and energy density of Lake Whitefish from Lake Champlain were high compared with those of Lake Whitefish from Lakes Michigan, Huron, and Ontario after the dreissenid invasion, and were similar to Lake Whitefish from Lake Erie; fish from Lakes Michigan, Huron, and Ontario consumed dreissenids, whereas fish from Lake Erie did not. Our comparisons of Lake Whitefish populations in Lake Champlain to those in the Great Lakes indicate that diet and condition of Lake Champlain Lake Whitefish were not negatively affected by the dreissenid mussel invasion.

  15. Contribution of computed tomography on chest drainage guidance

    International Nuclear Information System (INIS)

    Douvlou, E.; Tzortzis, D.; Vlachou, I.; Petrocheilou, G.; Safarika, V.; Fragopoulou, L.; Stathopoulou, S.; Kokkinis, C.

    2012-01-01

    Full text: Introduction: Thoracic collections (encysted pleural, endopulmonary, mediastinal) are common findings in major trauma hospitals mainly in need of further treatment as drainage. Objectives and tasks: To evaluate the CT-guidance, as a method of choice for thoracic drainages. Material and methods: 35 CT-guided chest drainages were performed for diagnostic and therapeutic purpose in 33 patients, with a mean age of 62 years. Of the 35 drainages, 31 were encysted at the pleura, 3 of them were endopulmonary and 1 was in the mediastinum. During the procedure we used needles of 15cm long and 18-22 G diameter for small collections while for 'large' collections drainage catheters of 10-16 F were placed. Results: All the CT-guided drainages of the chest were successful. Of them, 7 were pleural effusion collections while 24 were exudate collections (18 inflammatory and 6 neoplastic) and all were developed in the lungs or the mediastinum. In all the cases that a catheter was placed, full removal of the collections was achieved leading to a remarkable improvement of the patient's condition. Non-significant pneumothorax and tiny endopulmonary bleeding were the complications that occurred. Conclusion: CT-guided drainage of thoracic collections is an accurate and secure procedure and achieves high diagnostic and therapeutic results

  16. [Endoscopic ultrasound guided rendezvous for biliary drainage].

    Science.gov (United States)

    Knudsen, Marie Høxbro; Vilmann, Peter; Hassan, Hazem; Karstensen, John Gésdal

    2015-04-27

    Endoscopic retrograde cholangiography (ERCP) is currently standard treatment for biliary drainage. Endoscopic ultrasound guided rendezvous (EUS-RV) is a novel method to overcome an unsuccessful biliary drainage procedure. Under endoscopic ultrasound guidance a guidewire is passed via a needle from the stomach or duodenum to the common bile duct and from there on to the duodenum enabling ERCP. With a relatively high rate of success EUS-RV should be considered as an alternative to biliary drainage and surgical intervention.

  17. Effect of ultramafic intrusions and associated mineralized rocks on the aqueous geochemistry of the Tangle Lakes Area, Alaska: Chapter C in Studies by the U.S. Geological Survey in Alaska, 2011

    Science.gov (United States)

    Wang, Bronwen; Gough, Larry P.; Wanty, Richard B.; Lee, Gregory K.; Vohden, James; O’Neill, J. Michael; Kerin, L. Jack

    2013-01-01

    Stream water was collected at 30 sites within the Tangle Lakes area of the Delta mineral belt in Alaska. Sampling focused on streams near the ultramafic rocks of the Fish Lake intrusive complex south of Eureka Creek and the Tangle Complex area east of Fourteen Mile Lake, as well as on those within the deformed metasedimentary, metavolcanic, and intrusive rocks of the Specimen Creek drainage and drainages east of Eureka Glacier. Major, minor, and trace elements were analyzed in aqueous samples for this reconnaissance aqueous geochemistry effort. The lithologic differences within the study area are reflected in the major-ion chemistry of the water. The dominant major cation in streams draining mafic and ultramafic rocks is Mg2+; abundant Mg and low Ca in these streams reflect the abundance of Mg-rich minerals in these intrusions. Nickel and Cu are detected in 84 percent and 87 percent of the filtered samples, respectively. Nickel and Cu concentrations ranged from Ni life criteria; however, Cu concentrations exceed the hardness-based criteria for both chronic and acute exposure at some sites. The entire rare earth element (REE) suite is found in samples from the Specimen Creek sites MH5, MH4, and MH6 and, with the exception of Tb and Tm, at site MH14. These samples were all collected within drainages containing or downstream from Tertiary gabbro, diabase, and metagabbro (Trgb) exposures. Chondrite and source rock fractionation profiles for the aqueous samples were light rare earth element depleted, with negative Ce and Eu anomalies, indicating fractionation of the REE during weathering. Fractionation patterns indicate that the REE are primarily in the dissolved, as opposed to colloidal, phase.

  18. Glacial lake inventory and lake outburst potential in Uzbekistan.

    Science.gov (United States)

    Petrov, Maxim A; Sabitov, Timur Y; Tomashevskaya, Irina G; Glazirin, Gleb E; Chernomorets, Sergey S; Savernyuk, Elena A; Tutubalina, Olga V; Petrakov, Dmitriy A; Sokolov, Leonid S; Dokukin, Mikhail D; Mountrakis, Giorgos; Ruiz-Villanueva, Virginia; Stoffel, Markus

    2017-08-15

    Climate change has been shown to increase the number of mountain lakes across various mountain ranges in the World. In Central Asia, and in particular on the territory of Uzbekistan, a detailed assessment of glacier lakes and their evolution over time is, however lacking. For this reason we created the first detailed inventory of mountain lakes of Uzbekistan based on recent (2002-2014) satellite observations using WorldView-2, SPOT5, and IKONOS imagery with a spatial resolution from 2 to 10m. This record was complemented with data from field studies of the last 50years. The previous data were mostly in the form of inventories of lakes, available in Soviet archives, and primarily included localized in-situ data. The inventory of mountain lakes presented here, by contrast, includes an overview of all lakes of the territory of Uzbekistan. Lakes were considered if they were located at altitudes above 1500m and if lakes had an area exceeding 100m 2 . As in other mountain regions of the World, the ongoing increase of air temperatures has led to an increase in lake number and area. Moreover, the frequency and overall number of lake outburst events have been on the rise as well. Therefore, we also present the first outburst assessment with an updated version of well-known approaches considering local climate features and event histories. As a result, out of the 242 lakes identified on the territory of Uzbekistan, 15% are considered prone to outburst, 10% of these lakes have been assigned low outburst potential and the remainder of the lakes have an average level of outburst potential. We conclude that the distribution of lakes by elevation shows a significant influence on lake area and hazard potential. No significant differences, by contrast, exist between the distribution of lake area, outburst potential, and lake location with respect to glaciers by regions. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Assessment of the effect of anthropogenic pollution on the ecology of small shallow lakes using the palaeolimnological approach

    Directory of Open Access Journals (Sweden)

    Tiiu Koff

    2016-11-01

    Full Text Available Palaeolimnological techniques were utilized to determine the extent of the effect of anthropogenic pollutants or other environmental stressors on three lake ecosystems over the last 200 years. The ecology of the study sites has experienced significant changes due to various activities such as (1 extensive catchment drainage and using poisoning as a fish management measure, (2 seepage of urban waste water due to establishment and growth of a town and (3 artificial inflow of oil-shale mining waters. Sediment geochemical composition, fossil pigments and Cladocera remains from the sediment cores were analysed to demonstrate that sufficient information can be derived from sediments to permit a historical reconstruction. The integrated use of archival maps, historical records and lake monitoring data confirmed links to anthropogenic pollutants, primarily on the catchment level. The examples show how the sediment indicators provide unique insights into the causes and temporal dynamics of lake ecosystem changes relevant for environmental management decisions. This study demonstrates that palaeolimnology has great potential to assist in eutrophication assessment and management efforts in waterbodies.

  20. Weather, landscape, and management effects on nitrate and soluble phosphorus concentrations in subsurface drainage discharge in the western Lake Erie basin

    Science.gov (United States)

    Subsurface drainage, while an important and necessary agricultural production practice in the Midwest, contributes nitrate (NO3) and soluble phosphorus (P) to surface waters. Eutrophication (i.e., excessive enrichment of waters by NO3 and soluble P) supports harmful algal blooms (HABs) in receiving ...

  1. Applicability of API ZYM to capture seasonal and spatial variabilities in lake and river sediments.

    Science.gov (United States)

    Patel, Drashti; Gismondi, Renee; Alsaffar, Ali; Tiquia-Arashiro, Sonia M

    2018-05-02

    Waters draining into a lake carry with them much of the suspended sediment that is transported by rivers and streams from the local drainage basin. The organic matter processing in the sediments is executed by heterotrophic microbial communities, whose activities may vary spatially and temporally. Thus, to capture and evaluate some of these variabilities in the sediments, we sampled six sites: three from the St. Clair River and three from Lake St. Clair in spring, summer, fall, and winter of 2016. At all sites and dates, we investigated the spatial and temporal variations in 19 extracellular enzyme activities using API ZYM. Our results indicated that a broad range of enzymes were found to be active in the sediments. Phosphatases, lipases, and esterases were synthesized most intensively by the sediment microbial communities. No consistent difference was found between the lake and sediment samples. Differences were more obvious between sites and seasons. Sites with the highest metabolic (enzyme) diversity reflected the capacity of the sediment microbial communities to breakdown a broader range of substrates and may be linked to differences in river and lake water quality. The seasonal variability of the enzymes activities was governed by the variations of environmental factors caused by anthropogenic and terrestrial inputs, and provides information for a better understanding of the dynamics of sediment organic matter of the river and lake ecosystems. The experimental results suggest that API ZYM is a simple and rapid enzyme assay procedure to evaluate natural processes in ecosystems and their changes.

  2. Percutaneous transhepatic biliary drainage for hilar cholangiocarcinoma

    International Nuclear Information System (INIS)

    Qian Xiaojun; Jin Wenhui; Dai Dingke; Yu Ping; Gao Kun; Zhai Renyou

    2007-01-01

    Objective: To evaluate the effect of PTBD in treating malignant biliary obstruction caused by hilar cholangiocarcinoma. Methods: We retrospectively analyzed the data of 103 patients(M:62,F:41)with malignant obstructive jaundice caused by hilar cholangiocarcinoma. After taking percutaneous transhepatic cholangiography, metallic stent or plastic external catheter or external-internal catheter for drainage was deployed and then followed up was undertaken with clinical and radiographic evaluation and laboratory. examination. Results: All patients went though PTBD successfully (100%). According to Bismuth classification, all 103 cases consisted of I type(N=30), II type (N=30), III type (N=26) and IV type (N=17). Thirty-nine cases were placed with 47 stents and 64 eases with drainage tubes. 4 cases installed two stems for bilateral drainage, 2 cases installed two stents because of long segmental strictures with stent in stent, 1 case was placed with three stents, and 3 cases installed stent and plastic catheter together. Sixty-four cases received plastic catheters in this series, 35 cases installed two or more catheters for bilateral drainage, 28 cases installed external and internal drainage catheters, 12 eases installed external drainage catheters, and 24 eases installed both of them. There were 17 patients involving incorporative infection before procedure, 13 cases cured after procedure, and 15 new patients got inflammation after procedure. 13 cases showed increase of amylase (from May, 2004), 8 eases had bloody bile drainage and 1 case with pyloric obstruction. Total serum bilirubin reduced from (386 ± 162) μmol/L to (161 ± 117) μmol/L, (P<0.01) short term curative effect was related with the type of hilar cholangiocarcinoma. The survival time was 186 days(median), and 1, 3, 6, 12 month survival rate were 89.9%, 75.3%, 59.6%, 16.9%, respectively. Conclusion: Percutaneous transhepatic bile drainage is a safe and effective palliative therapy of malignant

  3. Environmental engineering interventions to control the expansion of salty lakes and marshes in siwa oasis.

    Science.gov (United States)

    El-Naggar, Hesham M

    2010-01-01

    The main activity in Siwa Oasis society is the agriculture, it depends on the groundwater. The agricultural drainage water and the unused saline water of naturally flowing springs are poured into four main salty lakes. This leads to an increase in the surface area of the saltwater lakes, marshes and rise in water table levels. to investigate some environmental engineering interventions to control the expansion of saltwater surface area in Siwa Oasis. Field visits, observation sheets and questionnaire survey with farmers were carried out to find out the main environmental problems in the Oasis. Environmental survey was carried out to collect different rocks and stones samples as natural construction materials from the desert that surrounds Siwa Oasis. Physical analyses, chemical composition and principal mechanical parameters were conducted on the collected samples. After the analysis, the safa rocks were the best natural construction materials in the Siwa Oasis. So, it could be used to build a construction wall around the salty lakes and marshes. Walls could convert the lakes into basins. The water will be evaporated at high rate during summer season by solar energy. After evaporation, the remaining salty rock named "karshef" can be easily collected from the lakes to be used as a low cost construction material for traditional building houses in Siwa Oasis. Therefore, the water level of lakes will be reduced to dryness and land could be reused as agricultural land. Among different rocks, safa rocks proved to be the best natural construction materials to construct a defense wall around the lakes and marshes. They will save about 80% of the concrete cost. The formed karshef rocks from the lakes will be used in the construction of the traditional building houses which will save about 90% of the concrete buildings. This intervention will save energy as it exchanges fuel consuming man-made material such as cement with naturally made material. This can reduce the green

  4. Foamed emulsion drainage: flow and trapping of drops.

    Science.gov (United States)

    Schneider, Maxime; Zou, Ziqiang; Langevin, Dominique; Salonen, Anniina

    2017-06-07

    Foamed emulsions are ubiquitous in our daily life but the ageing of such systems is still poorly understood. In this study we investigate foam drainage and measure the evolution of the gas, liquid and oil volume fractions inside the foam. We evidence three regimes of ageing. During an initial period of fast drainage, both bubbles and drops are very mobile. As the foam stabilises drainage proceeds leading to a gradual decrease of the liquid fraction and slowing down of drainage. Clusters of oil drops are less sheared, their dynamic viscosity increases and drainage slows down even further, until the drops become blocked. At this point the oil fraction starts to increase in the continuous phase. The foam ageing leads to an increase of the capillary pressure until the oil acts as an antifoaming agent and the foam collapses.

  5. Priority Scale of Drainage Rehabilitation of Cilacap City

    Science.gov (United States)

    Rudiono, Jatmiko

    2018-03-01

    Characteristics of physical condition of Cilacap City is relatively flat and low to sea level (approximately 6 m above sea level). In the event of a relatively heavy rainfall resulting in inundation at several locations. The problem of inundation is a serious problem if there is in a dense residential area or occurs in publicly-used infrastructure, such as roads and settlements. These problems require improved management of which include how to plan a sustainable urban drainage system and environmentally friendly. The development of Cilacap City is increasing rapidly, this causes drainage system based on the Drainage Masterplan Cilacap made in 2006 has not been able to accommodate rain water, so, it is necessary to evaluate the drainage masterplan for subsequent rehabilitation. Priority scale rehabilitation of the drainage sections as a guideline is an urgent need of rehabilitation in the next time period.

  6. Climate simulation and flood risk analysis for 2008-40 for Devils Lake, North Dakota

    Science.gov (United States)

    Vecchia, Aldo V.

    2008-01-01

    Devils Lake and Stump Lake in northeastern North Dakota receive surface runoff from a 3,810-square-mile drainage basin, and evaporation provides the only major water loss unless the lakes are above their natural spill elevation to the Sheyenne River. In September 2007, flow from Devils Lake to Stump Lake had filled Stump Lake and the two lakes consisted of essentially one water body with an elevation of 1,447.1 feet, about 3 feet below the existing base flood elevation (1,450 feet) and about 12 feet below the natural outlet elevation to the Sheyenne River (1,459 feet).Devils Lake could continue to rise, causing extensive additional flood damages in the basin and, in the event of an uncontrolled natural spill, downstream in the Red River of the North Basin. This report describes the results of a study conducted by the U.S. Geological Survey, in cooperation with the Federal Emergency Management Agency, to evaluate future flood risk for Devils Lake and provide information for developing updated flood-insurance rate maps and planning flood-mitigation activities such as raising levees or roads.In about 1980, a large, abrupt, and highly significant increase in precipitation occurred in the Devils Lake Basin and elsewhere in the Northern Great Plains, and wetter-than-normal conditions have persisted through the present (2007). Although future precipitation is impossible to predict, paleoclimatic evidence and recent research on climate dynamics indicate the current wet conditions are not likely to end anytime soon. For example, there is about a 72-percent chance wet conditions will last at least 10 more years and about a 37-percent chance wet conditions will last at least 30 more years.A stochastic simulation model for Devils Lake and Stump Lake developed in a previous study was updated and used to generate 10,000 potential future realizations, or traces, of precipitation, evaporation, inflow, and lake levels given existing conditions on September 30, 2007, and randomly

  7. Lake-level frequency analysis for Devils Lake, North Dakota

    Science.gov (United States)

    Wiche, Gregg J.; Vecchia, Aldo V.

    1996-01-01

    Two approaches were used to estimate future lake-level probabilities for Devils Lake. The first approach is based on an annual lake-volume model, and the second approach is based on a statistical water mass-balance model that generates seasonal lake volumes on the basis of seasonal precipitation, evaporation, and inflow. Autoregressive moving average models were used to model the annual mean lake volume and the difference between the annual maximum lake volume and the annual mean lake volume. Residuals from both models were determined to be uncorrelated with zero mean and constant variance. However, a nonlinear relation between the residuals of the two models was included in the final annual lakevolume model.Because of high autocorrelation in the annual lake levels of Devils Lake, the annual lake-volume model was verified using annual lake-level changes. The annual lake-volume model closely reproduced the statistics of the recorded lake-level changes for 1901-93 except for the skewness coefficient. However, the model output is less skewed than the data indicate because of some unrealistically large lake-level declines. The statistical water mass-balance model requires as inputs seasonal precipitation, evaporation, and inflow data for Devils Lake. Analysis of annual precipitation, evaporation, and inflow data for 1950-93 revealed no significant trends or long-range dependence so the input time series were assumed to be stationary and short-range dependent.Normality transformations were used to approximately maintain the marginal probability distributions; and a multivariate, periodic autoregressive model was used to reproduce the correlation structure. Each of the coefficients in the model is significantly different from zero at the 5-percent significance level. Coefficients relating spring inflow from one year to spring and fall inflows from the previous year had the largest effect on the lake-level frequency analysis.Inclusion of parameter uncertainty in the model

  8. Lake trout in northern Lake Huron spawn on submerged drumlins

    Science.gov (United States)

    Riley, Stephen C.; Binder, Thomas; Wattrus, Nigel J.; Faust, Matthew D.; Janssen, John; Menzies, John; Marsden, J. Ellen; Ebener, Mark P.; Bronte, Charles R.; He, Ji X.; Tucker, Taaja R.; Hansen, Michael J.; Thompson, Henry T.; Muir, Andrew M.; Krueger, Charles C.

    2014-01-01

    Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.

  9. An update on the drainage of pyogenic lung abscesses

    Directory of Open Access Journals (Sweden)

    Siraj O Wali

    2012-01-01

    Full Text Available Most lung abscesses (80-90% are now successfully treated with antibiotics; however, this conservative approach may occasionally fail. When medical treatment fails, pulmonary resection is usually advised. Alternatively, percutaneous transthoracic tube drainage or endoscopic drainage can be considered, though both remain controversial. In this communication, the medical literature focusing on percutaneous tube drainage efficacy, indications, techniques, complications, and mortality, as well as available data regarding endoscopic drainage are reviewed.

  10. An Optimal Balance between Efficiency and Safety of Urban Drainage Networks

    Science.gov (United States)

    Seo, Y.

    2014-12-01

    Urban drainage networks have been developed to promote the efficiency of a system in terms of drainage time so far. Typically, a drainage system is designed to drain water from developed areas promptly as much as possible during floods. In this regard, an artificial drainage system have been considered to be more efficient compared to river networks in nature. This study examined artificial drainage networks and the results indicate they can be less efficient in terms of network configuration compared with river networks, which is counter-intuitive. The case study of 20 catchments in Seoul, South Korea shows that they have wide range of efficiency in terms of network configuration and consequently, drainage time. This study also demonstrates that efficient drainage networks are more sensitive to spatial and temporal rainfall variation such as rainstorm movement. Peak flows increase more than two times greater in effective drainage networks compared with inefficient and highly sinuous drainage networks. Combining these results, this study implies that the layout of a drainage network is an important factor in terms of efficient drainage and also safety in urban catchments. Design of an optimal layout of the drainage network can be an alternative non-structural measures that mitigate potential risks and it is crucial for the sustainability of urban environments.

  11. Lake sturgeon population characteristics in Rainy Lake, Minnesota and Ontario

    Science.gov (United States)

    Adams, W.E.; Kallemeyn, L.W.; Willis, D.W.

    2006-01-01

    Rainy Lake contains a native population of lake sturgeon Acipenser fulvescens that has been largely unstudied. The aims of this study were to document the population characteristics of lake sturgeon in Rainy Lake and to relate environmental factors to year-class strength for this population. Gill-netting efforts throughout the study resulted in the capture of 322 lake sturgeon, including 50 recaptures. Lake sturgeon in Rainy Lake was relatively plump and fast growing compared with a 32-population summary. Population samples were dominated by lake sturgeon between 110 and 150 cm total length. Age–structure analysis of the samples indicated few younger (<10 years) lake sturgeon, but the smallest gill net mesh size used for sampling was 102 mm (bar measure) and would not retain small sturgeon. Few lake sturgeon older than age 50 years were captured, and maximum age of sampled fish was 59 years. Few correlations existed between lake sturgeon year-class indices and both annual and monthly climate variables, except that mean June air temperature was positively correlated with year-class strength. Analysis of Rainy Lake water elevation and resulting lake sturgeon year-class strength indices across years yielded consistent but weak negative correlations between late April and early June, when spawning of lake sturgeon occurs. The baseline data collected in this study should allow Rainy Lake biologists to establish more specific research questions in the future.

  12. Zooplankton communities in a large prealpine lake, Lake Constance: comparison between the Upper and the Lower Lake

    Directory of Open Access Journals (Sweden)

    Gerhard MAIER

    2005-08-01

    Full Text Available The zooplankton communities of two basins of a large lake, Lake Constance, were compared during the years 2002 and 2003. The two basins differ in morphology, physical and chemical conditions. The Upper Lake basin has a surface area of 470 km2, a mean depth of 100 and a maximum depth of 250 m; the Lower Lake basin has a surface area of 62 km2, a mean depth of only 13 and a maximum depth of 40 m. Nutrient, chlorophyll-a concentrations and mean temperatures are somewhat higher in the Lower than in the Upper Lake. Total abundance of rotifers (number per m2 lake surface was higher and rotifer development started earlier in the year in the Lower than in the Upper Lake. Total abundance of crustaceans was higher in the Upper Lake in the year 2002; in the year 2003 no difference in abundance could be detected between the lake basins, although in summer crustacean abundance was higher in the Lower than in the Upper Lake. Crustacean communities differed significantly between lake basins while there was no apparent difference in rotifer communities. In the Lower Lake small crustaceans, like Bosmina spp., Ceriodaphnia pulchella and Thermocyclops oithonoides prevailed. Abundance (number per m2 lake surface of predatory cladocerans, large daphnids and large copepods was much lower in the Lower than in the Upper Lake, in particular during the summer months. Ordination with nonmetric multidimensional scaling (NMS separated communities of both lakes along gradients that correlated with temperature and chlorophyll a concentration. Clutches of copepods were larger in the Lower than in the Upper Lake. No difference could be detected in clutch size of large daphnids between lake basins. Our results show that zooplankton communities in different basins of Lake Constance can be very different. They further suggest that the lack of large crustaceans in particular the lack of large predatory cladocerans in the Lower Lake can have negative effects on growth and

  13. Lake trout rehabilitation in Lake Erie: a case history

    Science.gov (United States)

    Cornelius, Floyd C.; Muth, Kenneth M.; Kenyon, Roger

    1995-01-01

    Native lake trout (Salvelinus namaycush) once thrived in the deep waters of eastern Lake Erie. The impact of nearly 70 years of unregulated exploitation and over 100 years of progressively severe cultural eutrophication resulted in the elimination of lake trout stocks by 1950. Early attempts to restore lake trout by stocking were unsuccessful in establishing a self-sustaining population. In the early 1980s, New York's Department of Environmental Conservation, Pennsylvania's Fish and Boat Commission, and the U.S. Fish and Wildlife Service entered into a cooperative program to rehabilitate lake trout in the eastern basin of Lake Erie. After 11 years of stocking selected strains of lake trout in U.S. waters, followed by effective sea lamprey control, lake trout appear to be successfully recolonizing their native habitat. Adult stocks have built up significantly and are expanding their range in the lake. Preliminary investigations suggest that lake trout reproductive habitat is still adequate for natural reproduction, but natural recruitment has not been documented. Future assessments will be directed toward evaluation of spawning success and tracking age-class cohorts as they move through the fishery.

  14. Microbiology of Lonar Lake and other soda lakes

    Science.gov (United States)

    Paul Antony, Chakkiath; Kumaresan, Deepak; Hunger, Sindy; Drake, Harold L; Murrell, J Colin; Shouche, Yogesh S

    2013-01-01

    Soda lakes are saline and alkaline ecosystems that are believed to have existed throughout the geological record of Earth. They are widely distributed across the globe, but are highly abundant in terrestrial biomes such as deserts and steppes and in geologically interesting regions such as the East African Rift valley. The unusual geochemistry of these lakes supports the growth of an impressive array of microorganisms that are of ecological and economic importance. Haloalkaliphilic Bacteria and Archaea belonging to all major trophic groups have been described from many soda lakes, including lakes with exceptionally high levels of heavy metals. Lonar Lake is a soda lake that is centered at an unusual meteorite impact structure in the Deccan basalts in India and its key physicochemical and microbiological characteristics are highlighted in this article. The occurrence of diverse functional groups of microbes, such as methanogens, methanotrophs, phototrophs, denitrifiers, sulfur oxidizers, sulfate reducers and syntrophs in soda lakes, suggests that these habitats harbor complex microbial food webs that (a) interconnect various biological cycles via redox coupling and (b) impact on the production and consumption of greenhouse gases. Soda lake microorganisms harbor several biotechnologically relevant enzymes and biomolecules (for example, cellulases, amylases, ectoine) and there is the need to augment bioprospecting efforts in soda lake environments with new integrated approaches. Importantly, some saline and alkaline lake ecosystems around the world need to be protected from anthropogenic pressures that threaten their long-term existence. PMID:23178675

  15. Nonsurgical drainage of splenic abscess

    International Nuclear Information System (INIS)

    Berkman, W.A.; Harris, S.A. Jr.; Bernardino, M.E.

    1983-01-01

    The mortality associated with intraabdominal abscess remains high despite modern surgical methods and antibiotics. Draingae of abscesses of the abdomen, retroperitoneum, pelvis, pancreatic pseudocyst, mediastinum, and lung may be treated effectively by percutaneous catheter placement. In several reports of percutaneous abdominal abscess drainage, only three cases of splenic abscess drainage have been reported. The authors have recently drained two splenic abscesses with the aid of computed tomography (CT) and emphasize several advantages of the percutaneous guided approach

  16. Aquatic balance in Vegoritis Lake, West Macedonia, Greece, relating to lignite mining works in the area

    Science.gov (United States)

    Dimitrakopoulos, D.; Grigorakou, E.; Koumantakis, J.

    2003-04-01

    Vegoritis Lake, which is located at Vegoritis closed Basin in West Macedonia, Greece, is the biggest lake in Greece. In 1994 the area of the lake was 35 Km2 with maximum depth 42 m at the northwestern part of the lake. It is the final receiving body of the surface runoff of the hydrological basin. Moreover, it is the surficial appearance of an enormous and not well-known karstic aquifer. Being a closed hydrological basin any interference in surface or groundwater conditions in every part of its area affects the level of the lake. The level of the lake in 1900 was 525 masl, in 1942 was 542 masl reaching the higher level of 543 masl in 1956. The increase of the level of the lake was due to the drainage of Ptolemais (Sarigiol) swamp through Soulou drain ditches that transfer the water in the lake. Since then, a continuous drawdown took place with small periods of rising of water level. Today, the level of the lake is declined in a smaller rate having reached the level of 510 masl. Water coming from the lake has been used in the past, and in some cases still does, for agricultural, industrial and domestic use, for hydropower generation and for the cooling system of power plants. Moreover, P.P.C. (Public Power Corporation of Greece) develops an intense activity in the area with the exploitation of the lignite deposits of the basin and power generation in several Power Plants. Few years ago significant quantities from Vegoritis Lake were used for hydro power of Agras Power Plant. With the elaboration of the existent data (water level measurements, recharge, discharge) the connection between the lowering of the surface of the lake and the subtracted quantities through the Arnissa Tunel the first years of its use, is obvious. The last twenty years the condition has change. Outflow through the Arnissa Tunnel for hydropower has stopped. The continued lowering of the level of the lake is caused, mainly, by overexploitation due to the intense increase of the irrigating land

  17. Water quality management in Lake Kinneret (Israel: hydrological and food web perspectives

    Directory of Open Access Journals (Sweden)

    Moshe GOPHEN

    2003-09-01

    . The similarity between seasonal fluctuations of food web components and residence time is a result of the natural subtropical conditions. The major effect on nutrient loads is due to inputs from the catchment and to a lesser extend to internal processes. Consequently, management implications aimed at lake water quality protection should be mostly directed towards nutrient removal in the drainage basin and loads reduction by pumping water for supply. When such a management is successfully implemented biomanipulation (fish removal might be efficient.

  18. High and Increasing Shoreline Erosion Rates of Thermokarst Lakes Set in Ice-Rich Permafrost Terrain of the Arctic Coastal Plain of Alaska

    Science.gov (United States)

    Bondurant, A. C.; Arp, C. D.; Jones, B. M.; Shur, Y.; Daanen, R. P.

    2017-12-01

    Thermokarst lakes are a dominant landform shaping landscapes and impacting permafrost on the Arctic Coastal Plain (ACP) of northern Alaska, a region of continuous permafrost. Here lakes cover greater than 20% of the landscape and drained lake basins cover an additional 50 to 60% of the landscape. The formation, expansion, and drainage of thaw lakes has been described by some researchers as part of a natural cycle that has reworked the ACP landscape during the Holocene. Yet the factors and processes controlling contemporary thermokarst lake expansion remain poorly described. This study focuses on the factors controlling expansion rates of thermokarst lakes in three ACP regions that vary in landscape history, ground-ice content, and lake morphology (i.e. size and depth), as well as evaluating changes through time. Through the use of historical aerial imagery, satellite imagery, and field observations, this study identifies the controlling factors at multiple spatial and temporal scales to better understand the processes relating to thermokarst lake expansion. Studies of 35 lakes across the ACP shows regional differences in expansion rate related to permafrost ice content ranging from an average expansion rate of 0.62 m/yr where ice content is highest ( 86%) to 0.16 m/yr where ice content is lowest (45%-71%). A subset of these lakes analyzed over multiple time periods show increasing rates of erosion, with average rates being 37% higher over the period 1979-2002 (0.73 m/yr) compared to 1948-1979 (0.53 m/yr). These increased rates of erosion have important implications for the regional hydrologic cycle and localized permafrost degradation. Predicting how thermokarst lakes will behave locally and on a landscape scale is increasingly important for managing habitat and water resources and informing models of land-climate interactions in the Arctic.

  19. Effect of viscosity on tear drainage and ocular residence time.

    Science.gov (United States)

    Zhu, Heng; Chauhan, Anuj

    2008-08-01

    An increase in residence time of dry eye medications including artificial tears will likely enhance therapeutic benefits. The drainage rates and the residence time of eye drops depend on the viscosity of the instilled fluids. However, a quantitative understanding of the dependence of drainage rates and the residence time on viscosity is lacking. The current study aims to develop a mathematical model for the drainage of Newtonian fluids and also for power-law non-Newtonian fluids of different viscosities. This study is an extension of our previous study on the mathematical model of tear drainage. The tear drainage model is modified to describe the drainage of Newtonian fluids with viscosities higher than the tear viscosity and power-law non-Newtonian fluids with rheological parameters obtained from fitting experimental data in literature. The drainage rate through canaliculi was derived from the modified drainage model and was incorporated into a tear mass balance to calculate the transients of total solute quantity in ocular fluids and the bioavailability of instilled drugs. For Newtonian fluids, increasing the viscosity does not affect the drainage rate unless the viscosity exceeds a critical value of about 4.4 cp. The viscosity has a maximum impact on drainage rate around a value of about 100 cp. The trends are similar for shear thinning power law fluids. The transients of total solute quantity, and the residence time agrees at least qualitatively with experimental studies. A mathematical model has been developed for the drainage of Newtonian fluids and power-law fluids through canaliculi. The model can quantitatively explain different experimental observations on the effect of viscosity on the residence of instilled fluids on the ocular surface. The current study is helpful for understanding the mechanism of fluid drainage from the ocular surface and for improving the design of dry eye treatments.

  20. Small hydropower plant in Ruetenen - Drainage water utilization from the Alpine motor way tunnel 'Seelisberg' in Switzerland

    International Nuclear Information System (INIS)

    Odermatt, K.; Ettlin, M.

    2001-01-01

    This report for the Swiss Federal Office of Energy (SFOE) describes a project that uses the drainage water from the Seelisberg motor way tunnel in central Switzerland to drive a small turbine that uses the fall distance between the collection point near the tunnel portal and the lake of Lucerne, which lies 48 meters below, to generate more than 100 kW of electrical power. The operation of the hydraulic power station and the experience gained during initial operation are described and the somewhat erratic amounts of water - depending on rainfall, snow-melting etc. - are discussed. Figures are given on the building and operational costs, electricity production and the price of the electricity produced. The report is illustrated with technical drawings and photos of the installation

  1. Preoperative biliary drainage in hilar cholangiocarcinoma: When and how?

    Science.gov (United States)

    Paik, Woo Hyun; Loganathan, Nerenthran; Hwang, Jin-Hyeok

    2014-01-01

    Hilar cholangiocarcinoma is a tumor of the extrahepatic bile duct involving the left main hepatic duct, the right main hepatic duct, or their confluence. Biliary drainage in hilar cholangiocarcinoma is sometimes clinically challenging because of complexities associated with the level of biliary obstruction. This may result in some adverse events, especially acute cholangitis. Hence the decision on the indication and methods of biliary drainage in patients with hilar cholangiocarcinoma should be carefully evaluated. This review focuses on the optimal method and duration of preoperative biliary drainage (PBD) in resectable hilar cholangiocarcinoma. Under certain special indications such as right lobectomy for Bismuth type IIIA or IV hilar cholangiocarcinoma, or preoperative portal vein embolization with chemoradiation therapy, PBD should be strongly recommended. Generally, selective biliary drainage is enough before surgery, however, in the cases of development of cholangitis after unilateral drainage or slow resolving hyperbilirubinemia, total biliary drainage may be considered. Although the optimal preoperative bilirubin level is still a matter of debate, the shortest possible duration of PBD is recommended. Endoscopic nasobiliary drainage seems to be the most appropriate method of PBD in terms of minimizing the risks of tract seeding and inflammatory reactions. PMID:24634710

  2. Modeling the Sedimentary Infill of Lakes in the East African Rift: A Case Study of Multiple versus Single Rift Basin Segments

    Science.gov (United States)

    Zhang, C.; Scholz, C. A.

    2016-12-01

    The sedimentary basins in the East African Rift are considered excellent modern examples for investigating sedimentary infilling and evolution of extensional systems. Some lakes in the western branch of the rift have formed within single-segment systems, and include Lake Albert and Lake Edward. The largest and oldest lakes developed within multi-segment systems, and these include Lake Tanganyika and Lake Malawi. This research aims to explore processes of erosion and sedimentary infilling of the catchment area in single-segment rift (SSR) and multi-segment rift (MSR) systems. We consider different conditions of regional precipitation and evaporation, and assess the resulting facies architecture through forward modeling, using state-of-the-art commercial basin modeling software. Dionisos is a three-dimensional numerical stratigraphic forward modeling software program, which simulates basin-scale sediment transport based on empirical water- and gravity-driven diffusion equations. It was classically used to quantify the sedimentary architecture and basin infilling of both marine siliciclastic and carbonate environments. However, we apply this approach to continental rift basin environments. In this research, two scenarios are developed, one for a MSR and the other for a SSR. The modeled systems simulate the ratio of drainage area and lake surface area observed in modern Lake Tanganyika and Lake Albert, which are examples of MSRs and SSRs, respectively. The main parameters, such as maximum subsidence rate, water- and gravity-driven diffusion coefficients, rainfall, and evaporation, are approximated using these real-world examples. The results of 5 million year model runs with 50,000 year time steps show that MSRs are characterized by a deep water lake with relatively modest sediment accumulation, while the SSRs are characterized by a nearly overfilled lake with shallow water depths and thick sediment accumulation. The preliminary modeling results conform to the features

  3. Recent Developments in the Treatment of Uranium Ores from the Elliot Lake District

    Energy Technology Data Exchange (ETDEWEB)

    Downes, K W [Extraction Metallurgy Division, Department of Mines and Technical Surveys, Ottawa (Canada)

    1967-06-15

    A summary of the results obtained during investigations on the treatment of uranium ores from the Elliot Lake district in the laboratories of the Mines Branch, and of developments in operating procedures introduced in the uranium mills in the Elliot Lake district, is presented. Concentration of Elliot Lake ore on a pilot-plant scale by a combined gravity-flotation procedure yielded a 90% recovery of uranium at a ratio of concentration of 2.4 to 1.0. The mineralogical composition of the ore, the flow sheet used and the reagents employed are described. An approximate cost estimate indicates that, although the capacity of an existing uranium leaching plant would be doubled by introducing the procedure, the production cost per pound of U{sub 3}0{sub 8} would not be affected. Bacterial leaching of Elliot Lake ore on a laboratory scale yielded, under favourable conditions, extractions of 90 per cent in 5 weeks, and of 95 per cent in 15 weeks. The conditions that were found to influence the leaching results are outlined, and the effects of the leaching solutions are discussed. The purification of ion exchange eluates by liquid-liquid extraction, using tri-n-butyl phosphate, dibutyl butylphosphonate and tri-capryl amine in a continuous process, yielded solutions from which refined ammonium diuranate was precipitated using gaseous ammonia. The effectiveness of the three extractants is discussed, and the effects of the procedures employed on the production costs per pound of U{sub 3}O{sub 8} is estimated. Some improvements in operating procedures introduced in the Elliot Lake district uranium mills are briefly described, and their effects on the operations are indicated. Present methods of controlling radiological pollution of drainage waters by uranium mill tailings are outlined. (author)

  4. Holocene Lake-Level Fluctuations of Lake Aricota, Southern Peru

    Science.gov (United States)

    Placzek, Christa; Quade, Jay; Betancourt, Julio L.

    2001-09-01

    Lacustrine deposits exposed around Lake Aricota, Peru (17° 22‧S), a 7.5-km2 lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal 14C reservoir effects (<350 yr). Diatomites associated with highstands several meters above the modern lake level indicate wet episodes. Maximum Holocene lake level was attained before 6100 14C yr B.P. and ended ∼2700 14C yr B.P. Moderately high lake levels occurred at 1700 and 1300 14C yr B.P. The highstand at Lake Aricota during the middle Holocene is coeval with a major lowstand at Lake Titicaca (16°S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes.

  5. Drainage of Splenic Abscess: A Case Report | Kombo | Nigerian ...

    African Journals Online (AJOL)

    ... and was managed by tube drainage. His post operative recovery was uneventful. Conclusion: Tube drainage of the splenic abscess is encouraged if there is easy access to the abscess and there is evidence of residual splenic tissue in the critically ill patient. Key Word: Tube drainage, splenic abscess, splenectomy.

  6. The construction technology of Chinese ancient city drainage facilities

    Science.gov (United States)

    Hequn, Li; Yufengyun

    2018-03-01

    In ancient china, according to the local natural environment, a variety of drainage facilities were built in order to excrete rainwater, domestic sewage, production wastewater and so on. These drainage facilities were mainly made of pottery, bricks, wood, stone, etc. For example, ceramic water pipelines, buried in the ground, connect together one by one, and there was a slight drop from one end to the other in favor of drainage. These measures can also be used for reference in today’s urban drainage and flood control.

  7. Evolution of soil and vegetation cover on the bottom of drained thermokarst lake (a case study in the European Northeast of Russia)

    Science.gov (United States)

    Kaverin, Dmitry; Pastukhov, Alexander

    2015-04-01

    The evolution of soils and landscapes has been studied in a lake bed of former thermokarst lake, which was totally drained in 1979. Melioration of thermokarst lakes was conducted experimentally and locally under Soviet economics program during 1970-s. The aim of the program was to increase in biomass productivity of virgin tundra permafrost-thermokarst sites under agricultural activities. The former thermokarst lake "Opytnoe" located in the Bolshezemelskaya Tundra, Russian European Northeast. The lake bed is covered by peat-mineral sediments, which serves as soil-forming sediments favoring subsequent permafrost aggradation and cryogenic processes as well. Initially, after drainage, swampy meadows had been developed almost all over the lake bed. Further on, succession of landscape went diversely, typical and uncommon tundra landscapes formed. When activated, cryogenic processes favored the formation of peat mounds under dwarf shrub - lichen vegetation (7% of the area). Frost cracks and peat circles affected flat mounds all over the former lake bottom. On drained peat sites, with no active cryogenic processes, specific grass meadows on Cryic Sapric Histosols were developed. Totally, permafrost-affected soils occupy 77% of the area (2011). In some part of the lake bed further development of waterlogging leads to the formation of marshy meadows and willow communities where Gleysols prevail. During last twenty years, permafrost degradation has occurred under tall shrub communities, and it will progress in future. Water erosion processes in the drained lake bottom promoted the formation of local hydrographic network. In the stream floodplain grassy willow-stands formed on Fluvisols (3% of the area). The study has been conducted under Clima-East & RFBR 14-05-31111 projects.

  8. Control Scheme of River-lake System from the View of Ecological Sponge Basin aiming at Sponge City Construction

    Science.gov (United States)

    Ding, X.; Liu, J.; Yang, Z.

    2017-12-01

    China is in the rapid advance of urbanization, and is promoting the Sponge City Construction (SCC) with the characteristics of natural accumulation, natural infiltration and natural purification. The Chinese government selected 16 and 14 cities as pilot cities in 2015 and 2016 respectively to carry out SCC taking Low Impact Development (LID) as the concept. However, in 2015 and 2016, water-logging occurred in 10 cities and 9 cities respectively during the pilot cities. Therefore, relying solely on LID can not solve the problem of urban flood and waterlogging. Except for a series of LID measures during the process of SCC, corresponding control scheme of river-lake system should be established to realize water-related targets. From the view of ecological sponge basin, this study presents the general idea of SCC both in and out of the unban built-up area and the corresponding control scheme of river-lake system: for the regions outside the built-up area, the main aim of SCC is to carry out the top-level design of urban flood control and waterlogging, establish the water security system outside the city for solving the problems including flood control, water resources, water environment and water ecology; for the built-up area, the main aim of SCC is to construct different kinds of urban sponge according to local conditions and develop multi-scale drainage system responding to different intensities of rainfall taking the river-lake system as the core. Taking Fenghuang County of Hunan Province as an example for the application research, the results indicate that, after the implementation of the control scheme of river-lake system: 1) together with other SCC measures including LID, the control rate of total annual runoff in Fenghuang County is expected to be 82.9% which meets the target requirement of 80%; 2) flood control and drainage standards in Fenghuang County can be increased from the current 10-year return to 20-year return; 3) urban and rural water supply

  9. Application of BIM Technology in Building Water Supply and Drainage Design

    Science.gov (United States)

    Wei, Tianyun; Chen, Guiqing; Wang, Junde

    2017-12-01

    Through the application of BIM technology, the idea of building water supply and drainage designers can be related to the model, the various influencing factors to affect water supply and drainage design can be considered more comprehensively. BIM(Building information model) technology assist in improving the design process of building water supply and drainage, promoting the building water supply and drainage planning, enriching the building water supply and drainage design method, improving the water supply and drainage system design level and building quality. Combined with fuzzy comprehensive evaluation method to analyze the advantages of BIM technology in building water supply and drainage design. Therefore, application prospects of BIM technology are very worthy of promotion.

  10. Genetic and Phenotypic Catalog of Native Resident Trout of the interior Columbia River Basin : FY-2001 Report : Populations in the Wenatchee, Entiat, Lake Chelan and Methow River Drainages.

    Energy Technology Data Exchange (ETDEWEB)

    Trotter, Patrick C.

    2001-10-01

    The 1994 Fish and Wildlife Program of the Northwest Power Planning Council specifies the recovery and preservation of population health of native resident fishes of the Columbia River Basin. Among the native resident species of concern are interior rainbow trout of the Columbia River redband subspecies Oncorhynchus mykiss gairdneri 1 and westslope cutthroat trout O. clarki lewisi. The westslope cutthroat trout has been petitioned for listing under the U. S. Endangered Species Act (American Wildlands et al. 1997). Before at-risk populations can be protected, their presence and status must be established. Where introgression from introduced species is a concern, as in the case of both westslope cutthroat trout and redband rainbow trout, genetic issues must be addressed as well. As is true with native trout elsewhere in the western United States (Behnke 1992), most of the remaining pure populations of these species in the Columbia River Basin are in relatively remote headwater reaches. The objective of this project was to photo-document upper Columbia Basin native resident trout populations in Washington, and to ascertain their species or subspecies identity and relative genetic purity using a nonlethal DNA technique. FY-2001 was year three (and final year) of a project in which we conducted field visits to remote locations to seek out and catalog these populations. In FY-2001 we worked in collaboration with the Wenatchee National Forest to catalog populations in the Wenatchee, Entiat, Lake Chelan, and Methow River drainages of Washington State.

  11. An overview of a uranium acidic mining lake (Caldas, Brazil): composition of the zooplankton community and limno-chemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, H.; Ferrari, C.; Roque, C.V.; Nascimento, M.R. [Brazilian Nuclear Energy Commission/Pocos de Caldas Laboratory (Brazil); Wisniewski, M.J. [Alfenas Federal University/Limnology Laboratory (Brazil); Rodgher, S. [Universidade Estadual Paulista Julio de Mesquita Filho/Science and Technology Laboratory (Brazil)

    2014-07-01

    This research represents an attempt to fill a gap in the information on the zooplankton composition and limno-chemical aspects of the uranium pit lake (Osamu Utsumi Pit, Brazil), affected by acid mine drainage. In the present study water samples were collected three-monthly, for a period of one year (2008-2009). The water samples from the uranium pit lake showed moderately acidic pH values (3.6 to 4.1), high values of the electrical conductivity, sulfate, uranium, fluoride, zinc, manganese and aluminum concentrations. The Rotifera cephalodella sp., Keratella americana, K. cochlearis, Bdelloidea order and the Cladocera Bosminopsis deitersi, Bosmina sp., were registered in the samples from the uranium pit lake with ADM. Of the species registered the Bdelloidea order was the most important in terms of density (17,500 - 77,778 ind m{sup -3}), since it occurred throughout the whole sampling period. In this study, probably the combined effect of moderately acid pH values and other potentially co-stressors factors, for example the high concentrations of stable and radioactive chemical species, could have influenced this richness and also the composition of the zooplankton species in the water samples from the uranium pit lake. Document available in abstract form only. (authors)

  12. Percutaneous transhepatic biliary drainage: analysis of 175 cases

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Kyung Jin; Lee, Sang Kwon; Kim, Tae Hun; Kim, Yong Joo; Kang, Duk Sik [College of Medicine, Kyungpook National Univ., Daegu (Korea, Republic of)

    1990-10-15

    Percutaneous transhepatic biliary drainage is a safe, effective and palliative means of treatment in biliary obstruction, especially in cases with malignant obstruction which are inoperable. 175 cases of transhepatic biliary drainage were performed on 119 patients with biliary obstruction from January 1985 to June 1989 at Kyung-pook National University Hospital. The causes of obstructive jaundice were 110 malignant diseases and 9 benign diseases. The most common indication for drainage was palliative intervention of obstruction secondary to malignant tumor in 89 cases. 86 cases of external drainage were performed including 3 cases of left duct approach, 29 cases of external-internal drainage and 60 cases of endoprosthesis. In external and external-internal drainages, immediate major complications (11.9%) occurred, including not restricted to, but sepsis, bile peritonitis and hemobilia. Delayed major complications (42.9%) were mainly catheter related. The delayed major complication of endoprosthesis resulted from obstruction of the internal stent. The mean time period to reobstruction of the internal stent was about 12 weeks. To improve management status, regular follow-up is required, as is education of both patients and their families as to when immediate clinical attention is mandated. Close communication amongst the varying medical specialities involved will be necessary to provide optional treatment for each patient.

  13. Percutaneous transhepatic biliary drainage: analysis of 175 cases

    International Nuclear Information System (INIS)

    Suh, Kyung Jin; Lee, Sang Kwon; Kim, Tae Hun; Kim, Yong Joo; Kang, Duk Sik

    1990-01-01

    Percutaneous transhepatic biliary drainage is a safe, effective and palliative means of treatment in biliary obstruction, especially in cases with malignant obstruction which are inoperable. 175 cases of transhepatic biliary drainage were performed on 119 patients with biliary obstruction from January 1985 to June 1989 at Kyung-pook National University Hospital. The causes of obstructive jaundice were 110 malignant diseases and 9 benign diseases. The most common indication for drainage was palliative intervention of obstruction secondary to malignant tumor in 89 cases. 86 cases of external drainage were performed including 3 cases of left duct approach, 29 cases of external-internal drainage and 60 cases of endoprosthesis. In external and external-internal drainages, immediate major complications (11.9%) occurred, including not restricted to, but sepsis, bile peritonitis and hemobilia. Delayed major complications (42.9%) were mainly catheter related. The delayed major complication of endoprosthesis resulted from obstruction of the internal stent. The mean time period to reobstruction of the internal stent was about 12 weeks. To improve management status, regular follow-up is required, as is education of both patients and their families as to when immediate clinical attention is mandated. Close communication amongst the varying medical specialities involved will be necessary to provide optional treatment for each patient

  14. The diversity of benthic mollusks of Lake Victoria and Lake Burigi ...

    African Journals Online (AJOL)

    Molluscan diversity, abundance and distribution in sediments of Lake Victoria and its satellite lake, Lake Burigi, were investigated. The survey was carried out in January and February 2002 for Lake Victoria and in March and April 2002 for Lake Burigi. Ten genera were recorded from four zones of Lake Victoria while only ...

  15. Achieving Long-Term Protection of Water Quality of Grand Lake St. Marys Through Implementation of Conservation Practices and Control of Phosphorus Input from Agricultural Drainage

    Science.gov (United States)

    Grand Lake St. Marys (GLSM), a 13,000 acre lake in northwestern Ohio, is experiencing toxic levels of algal blooms resulting primarily from phosphorus input from agricultural runoff. The algal blooms are so severe that the Ohio Department of Natural Resources advised against any...

  16. Lake Morphometry for NHD Lakes in Great Lakes Region 4 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  17. Hungry Horse Mitigation : Flathead Lake : Annual Progress Report 2008.

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Barry; Evarts, Les [Confederated Salish and Kootenai Tribes

    2009-08-06

    The Confederated Salish and Kootenai Tribes (CSKT) and Montana Fish Wildlife and Parks (MFWP) wrote the 'Fisheries Mitigation Plan for Losses Attributable to the Construction and Operation of Hungry Horse Dam' in March 1991 to define the fisheries losses, mitigation alternatives and recommendations to protect, mitigate and enhance resident fish and aquatic habitat affected by Hungry Horse Dam. On November 12, 1991, the Northwest Power Planning Council (NPPC) approved the mitigation plan with minor modifications, called for a detailed implementation plan, and amended measures 903(h)(1) through (7). A long-term mitigation plan was submitted in August 1992, was approved by the Council in 1993, and the first contract for this project was signed on November 11, 1993. The problem this project addresses is the loss of habitat, both in quality and quantity, in the Flathead Lake and River basin resulting from the construction and operation of Hungry Horse Dam. The purpose of the project is to both implement mitigation measures and monitor the biological responses to those measures including those implemented by Project Numbers 9101903 and 9101904. Goals and objectives of the 1994 Fish and Wildlife Program (Section 10.1) addressed by this project are the rebuilding to sustainable levels weak, but recoverable, native populations injured by the hydropower system. The project mitigates the blockage of spawning runs by Hungry Horse Dam by restoring and even creating spawning habitats within direct drainages to Flathead Lake. The project also addresses the altered habitat within Flathead Lake resulting from species shifts and consequent dominance of new species that restricts the potential success of mitigation measures. Specific goals of this project are to create and restore habitat and quantitatively monitor changes in fish populations to verify the efficacy of our mitigation measures. The project consists of three components: monitoring, restoration and research

  18. Hungry Horse Mitigation : Flathead Lake : Annual Progress Report 2007.

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Barry; Evarts, Les [Confederated Salish and Kootenai Tribes

    2008-12-22

    The Confederated Salish and Kootenai Tribes (CSKT) and Montana Fish Wildlife and Parks (MFWP) wrote the 'Fisheries Mitigation Plan for Losses Attributable to the Construction and Operation of Hungry Horse Dam' in March 1991 to define the fisheries losses, mitigation alternatives and recommendations to protect, mitigate and enhance resident fish and aquatic habitat affected by Hungry Horse Dam. On November 12, 1991, the Northwest Power Planning Council (NPPC) approved the mitigation plan with minor modifications, called for a detailed implementation plan, and amended measures 903(h)(1) through (7). A long-term mitigation plan was submitted in August 1992, was approved by the Council in 1993, and the first contract for this project was signed on November 11, 1993. The problem this project addresses is the loss of habitat, both in quality and quantity, in the Flathead Lake and River basin resulting from the construction and operation of Hungry Horse Dam. The purpose of the project is to both implement mitigation measures and monitor the biological responses to those measures including those implemented by Project Numbers 9101903 and 9101904. Goals and objectives of the 1994 Fish and Wildlife Program (Section 10.1) addressed by this project are the rebuilding to sustainable levels weak, but recoverable, native populations injured by the hydropower system. The project mitigates the blockage of spawning runs by Hungry Horse Dam by restoring and even creating spawning habitats within direct drainages to Flathead Lake. The project also addresses the altered habitat within Flathead Lake resulting from species shifts and consequent dominance of new species that restricts the potential success of mitigation measures. Specific goals of this project are to create and restore habitat and quantitatively monitor changes in fish populations to verify the efficacy of our mitigation measures. The project consists of three components: monitoring, restoration and research

  19. Superficial drainage studies in open-pit mines

    International Nuclear Information System (INIS)

    Teixeira Junior, P.B.; Leite, C.B.B.

    1984-01-01

    Drainage studies concerning large open-pit mining projects can be of vital importance throughout the mining activity itself as they may assist in avoiding activity interruptions due to drainage problems, therefore representing substantial savings. These studies should, in fact, be carried out from the initial activity stages and shall be considered in operational, project and planning decisions in order to optimize results and reduce costs. This specific study presents a drainage study systematization proposal, enphasazing economic decision criteria. The authors comment on studies of this nature developed at the Caldas uranium mine - NUCLEBRAS. (D.J.M.) [pt

  20. Gravity Drainage Kinetics of Papermaking Fibrous Suspensions

    Directory of Open Access Journals (Sweden)

    Przybysz Piotr

    2014-12-01

    Full Text Available The study analyses application possibilities of filtration and thickening models in evaluation of papermaking suspension drainage rate. The authors proposed their own method to estimate the drainage rate on the basis of an existing Ergun capillary model of liquid flow through a granular material. The proposed model was less sensitive to porosity changes than the Ergun model. An empirical verification proved robustness of the proposed approach. Taking into account discrepancies in the published data concerning how the drainage velocity of papermaking suspension is defined, this study examines which of the commonly applied models matches experimental results the best.

  1. Surgical vs ultrasound-guided drainage of deep neck space abscesses: a randomized controlled trial: surgical vs ultrasound drainage.

    Science.gov (United States)

    Biron, Vincent L; Kurien, George; Dziegielewski, Peter; Barber, Brittany; Seikaly, Hadi

    2013-02-26

    Deep neck space abscesses (DNAs) are relatively common otolaryngology-head and neck surgery emergencies and can result in significant morbidity with potential mortality. Traditionally, surgical incision and drainage (I&D) with antibiotics has been the mainstay of treatment. Some reports have suggested that ultrasound-guided drainage (USD) is a less invasive and effective alternative in select cases. To compare I&D vs USD of well-defined DNAs, using a randomized controlled clinical trial design. The primary outcome measure was effectiveness (length of hospital stay (LOHS) and safety), and the secondary outcome measure was overall cost to the healthcare system. Patients presenting to the University of Alberta Emergency Department with a well-defined deep neck space abscess were recruited in the study. Patients were randomized to surgical or US-guided drainage, placed on intravenous antibiotics and admitted with airway precautions. Following drainage with either intervention, abscess collections were cultured and drains were left in place until discharge. Seventeen patients were recruited in the study. We found a significant difference in mean LOHS between patients who underwent USD (3.1 days) vs I&D (5.2 days). We identified significant cost savings associated with USD with a 41% cost reduction in comparison to I&D. USD drainage of deep neck space abscesses in a certain patient population is effective, safe, and results in a significant cost savings to the healthcare system.

  2. Environmental geochemistry of dissolved and biogenic silicon and its nutrient limitation effects in an inland lake, China.

    Science.gov (United States)

    Lü, Changwei; He, Jiang; Wang, Bing; Zhou, Bin; Wang, Wei; Fan, Mingde

    2015-07-01

    Silicon (Si) processing and retention play a key role in nutrients biogeochemistry cycling in aquatic environment. In order to interpret the possibility of Si limitation, multivariate analysis was performed based on stoichiometric nutrients balance, distribution characteristics of dissolved silicon (DSi) and biogenic silica (BSi), adsorption behavior, and response relation of BSi with paleoenvironment in water-sediment system of Lake Daihai. The spatial distributions of DSi and BSi in the water-sediment system indicated that terrigenous inputs (such as the weathering of rock and soil in the drainage basin) was the main sources of Si. Meanwhile, grain sizes of sediments, water hydrogeochemistry, and space competition between diatoms and submergent or emerging plants also played important roles in regulating BSi spatial distributions. The sediments from the lake presented obvious releasing trend of Si at low initial concentrations (≤ 3 mg/L) in adsorption experiments, indicating that the sediments were the source of Si to the overlying water. Furthermore, the good response relation between BSi and paleoenvironment observed in the sediment profiles from Lake Daihai indicated that the main reasons for Si limitation to siliceous plankton were different during different periods. The multi-evidences of distribution characteristics, stoichiometric nutrient balance, adsorption behaviors, and response to paleoenvironment were jointly indicative of Si limitation on the primary production of siliceous plankton in Lake Daihai.

  3. Improved drainage with active chest tube clearance.

    Science.gov (United States)

    Shiose, Akira; Takaseya, Tohru; Fumoto, Hideyuki; Arakawa, Yoko; Horai, Tetsuya; Boyle, Edward M; Gillinov, A Marc; Fukamachi, Kiyotaka

    2010-05-01

    This study was performed to evaluate the efficacy of a novel chest drainage system. This system employs guide wire-based active chest tube clearance to improve drainage and maintain patency. A 32 Fr chest tube was inserted into pleural cavities of five pigs. On the left, a tube was connected to the chest canister, and on the right, the new system was inserted between the chest tube and chest canister. Acute bleeding was mimicked by periodic infusion of blood. The amount of blood drained from each chest cavity was recorded every 15 min for 2 h. After completion of the procedure, all residual blood and clots in each chest cavity were assessed. The new system remained widely patent, and the amount of drainage achieved with this system (670+/-105 ml) was significantly (P=0.01) higher than that with the standard tube (239+/-131 ml). The amount of retained pleural blood and clots with this system (150+/-107 ml) was significantly (P=0.04) lower than that with the standard tube (571+/-248 ml). In conclusion, a novel chest drainage system with active tube clearance significantly improved drainage without tube manipulations. 2010 Published by European Association for Cardio-Thoracic Surgery. All rights reserved.

  4. Fluoroscopy guided percutaneous catheter drainage of pneumothorax in good mid-term patency with tube drainage

    International Nuclear Information System (INIS)

    Park, Ga Young; Oh, Joo Hyung; Yoon, Yup; Sung, Dong Wook

    1995-01-01

    To evaluate efficacy and the safety of percutaneous catheter drainage in patients with pneumothorax that is difficult to treat with closed thoracotomy. We retrospectively reviewed effectiveness of percutaneous catheter drainage (PCD) in 10 patients with pneumothorax. The catheter was inserted under fluoroscopic guidance. Seven patients had spontaneous pneumothorax caused by tuberculosis (n =4), reptured bullae (n = 2), and histiocytosis-X (n = 1). Three patients had iatrogenic pneumothorax caused by trauma (n = 1) and surgery (n = 2). All procedures were performed by modified Seldinger's method by using 8F-20F catheter. All catheter were inserted successfully. In 9 of 10 patients, the procedure was curative without further therapy. Duration of catheter insertion ranged from 1 day to 26 days. In the remaining 1 patient in whom multiple pneumothorax occurred after operation, catheter insertion was performed twice. Percutaneous catheter drainage under fluoroscopic guidance is effective and safe procedure for treatment of pneumothorax in patients with failed closed thoracotomy

  5. Fluoroscopy guided percutaneous catheter drainage of pneumothorax in good mid-term patency with tube drainage

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ga Young; Oh, Joo Hyung; Yoon, Yup; Sung, Dong Wook [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    1995-10-15

    To evaluate efficacy and the safety of percutaneous catheter drainage in patients with pneumothorax that is difficult to treat with closed thoracotomy. We retrospectively reviewed effectiveness of percutaneous catheter drainage (PCD) in 10 patients with pneumothorax. The catheter was inserted under fluoroscopic guidance. Seven patients had spontaneous pneumothorax caused by tuberculosis (n =4), reptured bullae (n = 2), and histiocytosis-X (n = 1). Three patients had iatrogenic pneumothorax caused by trauma (n = 1) and surgery (n = 2). All procedures were performed by modified Seldinger's method by using 8F-20F catheter. All catheter were inserted successfully. In 9 of 10 patients, the procedure was curative without further therapy. Duration of catheter insertion ranged from 1 day to 26 days. In the remaining 1 patient in whom multiple pneumothorax occurred after operation, catheter insertion was performed twice. Percutaneous catheter drainage under fluoroscopic guidance is effective and safe procedure for treatment of pneumothorax in patients with failed closed thoracotomy.

  6. Dissolved organic matter and lake metabolism: Biogeochemistry and controls of nutrient flux dynamics in lakes: Technical progress report, 1 July 1986-30 June 1987

    International Nuclear Information System (INIS)

    Wetzel, R.G.

    1987-01-01

    Most lakes are small and possess large littoral and wetland components in the interface region between the open water per se and the drainage basin. Not only does the photosynthetic productivity of the surrounding littoral-wetland complex vastly exceed that of the pelagic zone, but the littoral-wetland vegetation and its intensive synthesis and decompositional metabolism regulate loading of inorganic nutrients passing to the open water (functioning as pulsed sources and sinks), and regulate loading of dissolved organic matter and particulate organic matter to the recipient open water, which by numerous complex pathways and mechanisms enhance or suppress pelagic productivity. Research emphasis was placed on the sources, fates, and interactions of dissolved and particulate organic matter in relation to inorganic chemical cycling: allochthonous loading to the lake system; and the coupled nutrient physiology and metabolism of phytoplankton, bacterial populations, macrophytes and attendant sessile algal-bacterial communities. Regulatory mechanisms of growth and rates of carbon and nutrient cycling were evaluated among the inorganic-organic influxes of allochthonous sources as they are controlled by wetland-littoral communities, the littoral photosynthetic producer-decomposer complex, the microflora of the sediment-water interface, and the microflora of the pelagic zone. 28 refs., 13 figs., 2 tabs

  7. Evaluation of the sustainability of road drainage systems

    Science.gov (United States)

    García-Diez, Iván; Palencia, Covadonga; Fernández Raga, María

    2017-04-01

    Water is the most erosive agent that exists on the linear structures, because they are constantly subjected to outdoor condition like irregular infiltration, frosts and different rain intensities. Another variables that highly influence in the entire lifetime of a natural drainage system are the spatial and temporal variability of the rainfall, the soil, the vegetation cover and the design. All this factors are affecting the vulnerability of the clearings and embankments, by wearing away the weakest materials which surround the roads or train rails, producing erosion and very bumpy surfaces. The result is that the original pattern, developped to disminished the lost of soil, is not properly working and it cannot eliminate water, with the consequence destruction of the linear structure after several rainfall periods, and the accumulation of material down slope. The propose of this research focuses on analysing the drainage systems used in spanish roads and railways lines. For this purpose, a revision of the literature has been done, and the main drainage solutions have been recovered, carrying out an evaluation of them from an environmental point of view. This procedure has been requested by several authors in the past (Nwa, E.U. & Twocock, J.G., 1969; Goulter, I.C., 1992), together with the need of designing a more sustainable drainage system. The final objective of this complete revision is to compare objetively the designs to valuate them in order to develop a new drainage patter which minimize the erosion, increasing the durability and effectiveness of the drainage system. For this purpose, it is neccesary to assure that all the systems will be compare under similar parameters of flow rate, vegetation, substrate, lenght, slope and total section. Only the channels pattern and water distribution will change. The analysis has been done following Liu, H. & Zhu, X.B., (2012), who pointed out that the main parameters to take into account to select a road drainage

  8. Subdural drainage versus subperiosteal drainage in burr-hole trepanation for symptomatic chronic subdural hematomas.

    Science.gov (United States)

    Bellut, David; Woernle, Christoph Michael; Burkhardt, Jan-Karl; Kockro, Ralf Alfons; Bertalanffy, Helmut; Krayenbühl, Niklaus

    2012-01-01

    Symptomatic chronic subdural hematoma (scSDH) is one of the most frequent diseases in neurosurgical practice, and its incidence is increasing. However, treatment modalities are still controversial. The aim of this retrospective single-center study is to compare for the first time two surgical methods in the treatment of subdural hematoma that have been proven to be efficient in previous studies in a direct comparison. We analyzed the data of 143 scSDHs in 113 patients undergoing surgery for subdural hematoma with placement of subperiosteal or subdural drainage after double burr-hole trepanation for hematoma evacuation. Overall, there were no statistically significant differences regarding general patient characteristics, preoperative and postoperative symptoms, postoperative hematoma remnant, rates of recurrences, mortality, complications, and outcome at discharge and at 3-month follow up between the groups. There was a close to significant tendency of lower mortality after placement of subperiosteal drainage system and a tendency towards lower rate of recurrent hematoma after placement of subdural drainage system. Our study shows for the first time a direct comparison of two mainly used surgical techniques in the treatment of scSDH. Both methods proved to be highly effective, and general patient data, complications, outcome and mortality of both groups are equal or superior compared with previously published series. Because there is a clear tendency to less mortality and fewer serious complications, treatment with double burr-hole trepanation, irrigation, and placement of subperiosteal drainage is our treatment of choice in patients with predictable high risk of complications. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Spatial and temporal genetic diversity of lake whitefish (Coregonus clupeaformis (Mitchill)) from Lake Huron and Lake Erie

    Science.gov (United States)

    Stott, Wendylee; Ebener, Mark P.; Mohr, Lloyd; Hartman, Travis; Johnson, Jim; Roseman, Edward F.

    2013-01-01

    Lake whitefish (Coregonus clupeaformis (Mitchill)) are important commercially, culturally, and ecologically in the Laurentian Great Lakes. Stocks of lake whitefish in the Great Lakes have recovered from low levels of abundance in the 1960s. Reductions in abundance, loss of habitat and environmental degradation can be accompanied by losses of genetic diversity and overall fitness that may persist even as populations recover demographically. Therefore, it is important to be able to identify stocks that have reduced levels of genetic diversity. In this study, we investigated patterns of genetic diversity at microsatellite DNA loci in lake whitefish collected between 1927 and 1929 (historical period) and between 1997 and 2005 (contemporary period) from Lake Huron and Lake Erie. Genetic analysis of lake whitefish from Lakes Huron and Erie shows that the amount of population structuring varies from lake to lake. Greater genetic divergences among collections from Lake Huron may be the result of sampling scale, migration patterns and demographic processes. Fluctuations in abundance of lake whitefish populations may have resulted in periods of increased genetic drift that have resulted in changes in allele frequencies over time, but periodic genetic drift was not severe enough to result in a significant loss of genetic diversity. Migration among stocks may have decreased levels of genetic differentiation while not completely obscuring stock boundaries. Recent changes in spatial boundaries to stocks, the number of stocks and life history characteristics of stocks further demonstrate the potential of coregonids for a swift and varied response to environmental change and emphasise the importance of incorporating both spatial and temporal considerations into management plans to ensure that diversity is preserved.

  10. Pleistocene lake level changes in Western Mongolia

    Science.gov (United States)

    Borodavko, P. S.

    2009-04-01

    lake is 75 km long and 31 km wide. Its mean depth is 47 m, with the deepest point reaching 80 m, and its total water volume is 66,034 km3 and drainage basin 115,500 km2. The only water flowing into it is Galbiyn Hooloi. Hara-Us Nur Lake is a fresh-water (mineralization ca 107-348 mg/l, pH -7.8) basin situated in the Mongolian Great Lakes Depression [2]. Hara-Us Nur is fed by the Kobdo and Buyant rivers, which start in the Mongolian Altay, and outflows via the Chano-Hairkhan River into Hara-Us Nur Lake. Hara-Us Nur is divided by the Ak-Bashi Island into two subbasins. It has a water area of 1857 km2 with a length of 72.2 km and a maximum width of 27 km [4]. The maximum depth is 4 m and the average depth is ca 2 m [5,6]. The terraced lake shores are covered by steppe and desert vegetation. Pharagmites is abundant in the river deltas and close to the shore-line and the shallow-water littoral is covered by rich aquatic vegetation, including Myriophyllum verticulatum, Zannichelia pedunculata, Utricularia vulgaris [3]. Hara-Nur Lake is situated in the desert steppe subzone of the Mongolian Great Lakes Depression. The fresh-water Hara-Nur Lake receives inflow from Hara-Us Nur Lake via the Chano-Hairkhan River. There are two outflows from the lake one outflow is via a 10 km-long channel which flows to the Dzabhan River, which in turn flows into the closed Hyargas Lake. The other outflow is a small semi-permanent stream with flows southward into the closed brackish-water Dorgon Lake. Hara-Nur has a water area of 57,500 ha, with a length of 37 km and a maximum width of ca 24 km. The maximum depth is 7 m and the average depth is ca 4 m. The mean water mineralization is 260 mg/l and the pH is 8.0 [5]. The catchment area is ca 7,200,000 ha. Lake Ureg located in the Mongolian Altay at an altitude of 1425 m.a.s.1., this lake has an area 237.6 km2 and maximum depth of 48 m. Secchi disk transparency is to 8 m. Macrophyte beds cover up to 20 per cent of the lake area, with the common

  11. Ultrasound guided transrectal catheter drainage of pelvic collections.

    Science.gov (United States)

    Thakral, Anuj; Sundareyan, Ramaniwas; Kumar, Sheo; Arora, Divya

    2015-01-01

    The transrectal approach to draining deep-seated pelvic collections may be used to drain The transrectal approach to draining deep-seated pelvic collections may be used to drain intra-abdominal collections not reached by the transabdominal approach. We discuss 6 patients with such pelvic collections treated with transrectal drainage using catheter placement via Seldinger technique. Transrectal drainage helped achieve clinical and radiological resolution of pelvic collections in 6 and 5 of 6 cases, respectively. It simultaneously helped avoid injury to intervening bowel loops and neurovascular structures using real-time visualization of armamentarium used for drainage. Radiation exposure from fluoroscopic/CT guidance was avoided. Morbidity and costs incurred in surgical exploration were reduced using this much less invasive ultrasound guided transrectal catheter drainage of deep-seated pelvic collections.

  12. Intermediate report on the problems of warm water drainage

    International Nuclear Information System (INIS)

    1976-01-01

    The investigation into the solution of the problems of warm water drainage and its related matters was conducted, and the result was summarized by the warm water drainage sectional committee of the central public nuisance-prevention council entrusted by the Environment Agency. The first section of this report deals with the background of the warm water drainage problems. In December 1970, the environmental pollution prevention act was revised so as to include warm water drainage in the law. The second section deals with the progress of deliberation by the sectional committee. The third section deals with the actual conditions of warm water drainage. The temperature difference at the inlet and outlet of water was 5 to 11 0 C in power plants, 5 to 16 0 C in iron and steel works, 4 to 11 0 C in petroleum refineries, and 7 to 25 0 C in petrochemical plants. The amount of heat energy discharged from power plants was greater than that from the others. Other sections deal with its effects on the living things in water, the forecast of diffusion of warm drainage, the concept of the regulation of warm drainage, and the present countermeasure. Twelve points which require future investigation are listed. They are the change in the phases of living things affected by the change in temperature and flow of warm drainage, the effects on fishery resources, the estimation system for the environmental calorific capacity in the sea, the mechanism of diffusion and the forecasting method for the diffusion range. (Iwakiri, K.)

  13. An iron-age cultural hiatus enigma: mega-flooding and human settlement abandonment over the last millennium in the Lanyang Drainage System, northeastern Taiwan

    Science.gov (United States)

    Huang, Jyh-Jaan; Wei, Kuo-Yen; Löwemark, Ludvig; Song, Sheng-Rong; Huh, Chih-An; Chuang, Chih-Kai; Yang, Tien-Nan; Lee, Meng-Yang; Chen, Yu-Be; Lee, Teh-Quei

    2015-04-01

    Active tectonic activities and frequent typhoon landfalls make Taiwan unique in having very high rates of uplift, precipitation, denudation and sedimentation. Particularly, intense rainfall associated with typhoons often causes flooding, large-scale landslides, and debris flows in river systems. Such natural disasters have affected human societies both at present and in the past; the Typhoon Morakot in 2009 may serve as a modern example of such events. Kiwulan is a newly discovered archaeological site from the Iron Age situated on the Lanyang Plain in NE Taiwan. In the deposits from this society, a cultural hiatus centered around 1200-1500 cal. yr AD is found, suggesting that the settlement was abandoned for a period of a few hundred years before being recolonized. Until now it has remained a mystery what caused this cultural hiatus. This study assembles radiocarbon dates of upland river terraces, organic proxies in flood plain lake sediments, and content of wood shreds in nearby marine sediments from the continental slope off NE Taiwan. These records are synthesized to infer the frequency and magnitude of ancient flood events over the past 1250 years in the Lanyang Drainage System in northeastern Taiwan. Alluvial fan terraces distributed along the banks of the upper Lanyang River are considered to be the results of ancient debris flow events, and their radiocarbon dates fall in two time ranges: 850-1100 and 1400-1600 cal. yr AD. Organic proxies which representing terrestrial organic input were measured from bulk sediments of Lake Dahu and Lake Meihua in the Lanyang Plain. Peak values of TOC, C/N ratio and organic indicator (inc/coh) from Itrax-XRF core scanner measurements are conspicuous during 900-950, and 1400-1500 cal. yr AD, implying frequent flood events. Moreover, abundance peaks of wood shreds and peaks in the C/N ratio in marine box core ORI-801-7A from the continental slope SE of the Lanyang Plain are dated to about 950-1050 and 1450-1550 cal. yr AD

  14. Development of laundry drainage treatment system with ceramic ultra filter

    International Nuclear Information System (INIS)

    Kanda, Masanori; Kurahasi, Takafumi

    1995-01-01

    A compact laundry drainage treatment system (UF system hereafter) with a ceramic ultra filter membrane (UF membrane hereafter) has been developed to reduce radioactivity in laundry drainage from nuclear power plants. The UF membrane is made of sintered fine ceramic. The UF membrane has 0.01 μm fine pores, resulting in a durable, heat-resistant, and corrosion-resistant porous ceramic filter medium. A cross-flow system, laundry drainage is filtrated while it flows across the UF membrane, is used as the filtration method. This method creates less caking when compared to other methods. The UF membrane is back washed at regular intervals with permeated water to minimize caking of the filter. The UF membrane and cross-flow system provides long stable filtration. The ceramic UF membrane is strong enough to concentrate suspended solids in laundry drainage up to a weight concentration of 10%. The final concentrated laundry drainage can be treated in an incinerator. The performance of the UF system was checked using radioactive laundry drainage. The decontamination factor of the UF system was 25 or more. The laundry drainage treatment capacity and concentration ratio of the UF system, as well as the service life of the UF membrane were also checked by examination using simulated non-radioactive laundry drainage. Even though laundry drainage was concentrated 1000 times, the UF system showed good permeated water quality and permeated water flux. (author)

  15. Proceedings of the international land reclamation and mine drainage conference and third international conference on the abatement of acidic drainage. Volume 1: Mine drainage -- SP 06A-94

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Volume 1 of these proceedings is divided into the following sections: Modeling mine water quality; Water treatment with wetlands; Predicting mine water quality; Water treatment--Chemical; Control of acid mine drainage--Wet covers; Site characterization monitoring; Control of acid mine drainage--Alkaline addition; and Mine water geochemistry. Papers dealing with or applicable to coal or uranium mining have been processed separately for inclusion on the data base

  16. Conditions to generate Steam Fog Occurred around the Chungju Lake in the South Korea

    Science.gov (United States)

    Byungwoo, J.

    2017-12-01

    We have collected the field observation data of the steam fog occurred around the Chungju Lake in the South Korea for 3 years(2014 2016) and analyzed conditions in which the steam fog occurred. The Chungju Lake is an artificial lake made by the Chungju Dam with a water storage of 2.7 billion tons, which is the second largest in South Korea. The Chungju Dam have discharged water of the average 2.2 million tons downstream to produce electricity per day. The drainage water heats downstream of the Chungju dam and the air above water surface of downstream of that. When the warm, humid air above the downstream water mixed with cold air mass, it caused "steam fog" around the downstream of Chungju lake regardless of amount of the discharged water. The condition that promote the generation of steam fog in autumn and winter is as follows: (1) cloudless night with light winds below 1.5 m/s. (2) The differences between the temperature of discharged water from the Chungju Dam and the air temperature above the discharged water varied from 3° to 15° in autumn, from 15° to 20° in winter respectively. (3) When stream fog was generated, sensible heat flux ranged in autumn from 5 to 15 W/m2, in winter from 15 to 20 W/m2 respectively. Latent heat flux ranged in autumn from 15 to 20 W/m2, in winter from 10 to 15 W/m2 respectively.

  17. Energy density of lake whitefish Coregonus clupeaformis in Lakes Huron and Michigan

    Science.gov (United States)

    Pothoven, S.A.; Nalepa, T.F.; Madenjian, C.P.; Rediske, R.R.; Schneeberger, P.J.; He, J.X.

    2006-01-01

    We collected lake whitefish Coregonus clupeaformis off Alpena and Tawas City, Michigan, USA in Lake Huron and off Muskegon, Michigan USA in Lake Michigan during 2002–2004. We determined energy density and percent dry weight for lake whitefish from both lakes and lipid content for Lake Michigan fish. Energy density increased with increasing fish weight up to 800 g, and then remained relatively constant with further increases in fish weight. Energy density, adjusted for weight, was lower in Lake Huron than in Lake Michigan for both small (≤800 g) and large fish (>800 g). Energy density did not differ seasonally for small or large lake whitefish or between adult male and female fish. Energy density was strongly correlated with percent dry weight and percent lipid content. Based on data from commercially caught lake whitefish, body condition was lower in Lake Huron than Lake Michigan during 1981–2003, indicating that the dissimilarity in body condition between the lakes could be long standing. Energy density and lipid content in 2002–2004 in Lake Michigan were lower than data for comparable sized fish collected in 1969–1971. Differences in energy density between lakes were attributed to variation in diet and prey energy content as well as factors that affect feeding rates such as lake whitefish density and prey abundance.

  18. Holocene evolution of the River Nile drainage system as revealed from the Lake Dendi sediment record, central Ethiopian highlands

    Science.gov (United States)

    Wagner, B.; Viehberg, F. A.; Wennrich, V.; Junginger, A.; Kolvenbach, A.; Rethemeyer, J.; Schaebitz, F.; Schmiedl, G. H.

    2015-12-01

    A 12 m long sediment sequence from Dendi Crater lakes, located on the central Ethiopian Plateau, was analysed with sedimentological and geochemical methods to reconstruct the regional environmental history. Bulk organic carbon samples from 23 horizons throughout the sequence were used for AMS radiocarbon dating and indicate that the sediment sequence spans the last ca. 12 cal kyr BP. Microscope analyses and sedimentological data reveal three tephra layers, of which the most prominent layer with a thickness of ~2 m was deposited at 10.2 cal kyr BP and probably originates from an eruption of the Wenchi crater 12 km to the west of the Dendi lakes. Sedimentological data of the pelagic deposits indicate shifts in erosion and rainfall throughout the record. A decrease in Ca and Sr at 11.6 cal kyr BP is related to the shift of less humid condition during the Younger Dryas (YD) to the return to full humid conditions of the African Humid Period (AHP). Single thin horizons with high carbonate content or high Ti and K imply that short spells of dry conditions and significantly increased rainfall superimpose the generally more humid conditions during the AHP. The end of the AHP is gradual. Relatively stable and less humid conditions characterised the Dendi Crater lakes until around 3.9 cal kyr BP. A highly variable increase in clastic matter over the last 1500 years indicates higher erosion due to short-term variations in precipitation within the Dendi catchment. Overall, the sediment record suggests moderate change of precipitation during the Holocene, which is probably due to their exposed location in the Ethiopian highlands. The data from the Dendi Crater lakes show, in concert with other records from the Nile catchment and the Eastern Mediterranean Sea (EMS), that the Blue Nile provided the main freshwater source for maintaining EMS stratification and sapropel S1 formation between ca. 10.0 and 8.7 cal kyr BP. Subsequent aridification is recorded from equatorial East Africa

  19. Numerical Three-Dimensional Model of Airport Terminal Drainage System

    Directory of Open Access Journals (Sweden)

    Strzelecki Michał

    2014-03-01

    Full Text Available During the construction of an airport terminal it was found that as a result of the hydrostatic pressure of underground water the foundation plate of the building had dangerously shifted in the direction opposite to that of the gravitational forces. The only effective measure was to introduce a drainage system on the site. The complex geology of the area indicated that two independent drainage systems, i.e., a horizontal system in the Quaternary beds and a vertical system in the Tertiary water-bearing levels, were necessary. This paper presents numerical FEM calculations of the two drainage systems being part of the airport terminal drainaged esign. The computer simulation which was carried out took into consideration the actual effect of the drainage systems and their impact on the depression cone being formed in the two aquifers.

  20. Land drainage and restoration of land after NCB opencast mining

    Energy Technology Data Exchange (ETDEWEB)

    Bragg, N.

    The author outlines the MAFF Field Drainage Research Unit's research into drainage of reinstated land. Current investigations have aimed at identifying the problems of reinstated soil and how they affect drainage design. Experiments on efficiency of permeable field drains and non-permeable field drains are mentioned. Further work is needed to examine long-term effects of storage on soil structure and whether existing drainage can be revitalised by secondary treatment.

  1. Effects of lake trout refuges on lake whitefish and cisco in the Apostle Islands Region of Lake Superior

    Science.gov (United States)

    Zuccarino-Crowe , Chiara M.; Taylor, William W.; Hansen, Michael J.; Seider, Michael J.; Krueger, Charles C.

    2016-01-01

    Lake trout refuges in the Apostle Islands region of Lake Superior are analogous to the concept of marine protected areas. These refuges, established specifically for lake trout (Salvelinus namaycush) and closed to most forms of recreational and commercial fishing, were implicated as one of several management actions leading to successful rehabilitation of Lake Superior lake trout. To investigate the potential significance of Gull Island Shoal and Devils Island Shoal refuges for populations of not only lake trout but also other fish species, relative abundances of lake trout, lake whitefish (Coregonus clupeaformis), and cisco (Coregonus artedi) were compared between areas sampled inside versus outside of refuge boundaries. During 1982–2010, lake trout relative abundance was higher and increased faster inside the refuges, where lake trout fishing was prohibited, than outside the refuges. Over the same period, lake whitefish relative abundance increased faster inside than outside the refuges. Both evaluations provided clear evidence that refuges protected these species. In contrast, trends in relative abundance of cisco, a prey item of lake trout, did not differ significantly between areas inside and outside the refuges. This result did not suggest indirect or cascading refuge effects due to changes in predator levels. Overall, this study highlights the potential of species-specific refuges to benefit other fish species beyond those that were the refuges' original target. Improved understanding of refuge effects on multiple species of Great Lakes fishes can be valuable for developing rationales for refuge establishment and predicting associated fish community-level effects.

  2. Depth of cinder deposits and water-storage capacity at Cinder Lake, Coconino County, Arizona

    Science.gov (United States)

    Macy, Jamie P.; Amoroso, Lee; Kennedy, Jeff; Unema, Joel

    2012-01-01

    The 2010 Schultz fire northeast of Flagstaff, Arizona, burned more than 15,000 acres on the east side of San Francisco Mountain from June 20 to July 3. As a result, several drainages in the burn area are now more susceptible to increased frequency and volume of runoff, and downstream areas are more susceptible to flooding. Resultant flooding in areas downgradient of the burn has resulted in extensive damage to private lands and residences, municipal water lines, and roads. Coconino County, which encompasses Flagstaff, has responded by deepening and expanding a system of roadside ditches to move flood water away from communities and into an area of open U.S. Forest Service lands, known as Cinder Lake, where rapid infiltration can occur. Water that has been recently channeled into the Cinder Lake area has infiltrated into the volcanic cinders and could eventually migrate to the deep regional groundwater-flow system that underlies the area. How much water can potentially be diverted into Cinder Lake is unknown, and Coconino County is interested in determining how much storage is available. The U.S. Geological Survey conducted geophysical surveys and drilled four boreholes to determine the depth of the cinder beds and their potential for water storage capacity. Results from the geophysical surveys and boreholes indicate that interbedded cinders and alluvial deposits are underlain by basalt at about 30 feet below land surface. An average total porosity for the upper 30 feet of deposits was calculated at 43 percent for an area of 300 acres surrounding the boreholes, which yields a total potential subsurface storage for Cinder Lake of about 4,000 acre-feet. Ongoing monitoring of storage change in the Cinder Lake area was initiated using a network of gravity stations.

  3. Drainage Water Filtration

    Science.gov (United States)

    Tile drainage discharge from managed turf is known to carry elevated concentrations of agronomic fertilizers and chemicals. One approach being considered to reduce the transport is end-of-tile-filters. Laboratory and field studies have been initiated to address the efficacy of this approach. Result...

  4. NORM levels in Spanish pit lakes and their impact in neighboring environments

    Energy Technology Data Exchange (ETDEWEB)

    Manjon, G.; Galvan, J.A.; Mantero, J.; Diaz, I.; Garcia-Tenorio, R. [University of Seville (Spain)

    2014-07-01

    The Iberian Pyrite Belt (IPB) is a part of the South Zone of the Hercynian Iberian Massif (SW of Iberian Peninsula), being pyrite (FeS{sub 2}) the main mineral associated to this volcano-sedimentary complex. The intensive mining activities in the area, which started in the Roman Empire, have generated mine pits where underground and/or rainwater are stored. These stored waters have produced oxidation of pyrite and, consequently, the pH of pit water has become acid (pH around 2), causing the dissolution of metals and natural radionuclides. The main objective of this work is to show and discuss the levels found for different natural radionuclides (mainly uranium isotopes and daughters via α/γ spectrometry) in water samples and sediments collected from several mine pit lakes located in the south-west of Spain. The waters of the studied pit lakes can interact with the environment, and a fraction can be transferred to surrounding aquifers and even to the main river of the zone (the Odiel River). The waters of this river, when cross the mining area, show low pH values and high concentrations of U-isotopes due to acid mining drainage. Through the analysis of several isotope activity ratios, the presence of natural radionuclides in these pit lakes and its influence in the surrounding area and Odiel river will be additionally evaluated. Document available in abstract form only. (authors)

  5. The effect of climate change on urban drainage

    DEFF Research Database (Denmark)

    Grum, M.; Jørgensen, A.T.; Johansen, R.M.

    2006-01-01

    and consequences of climate change on urban drainage and urban runoff pollution issues. This study uses predictions from a regional climate model to look at the effects of climate change on extreme precipitation events. Results are presented in terms of point rainfall extremes. The analysis involves three steps......That we are in a period of extraordinary rates of climate change is today evident. These climate changes are likely to impact local weather conditions with direct impacts on precipitation patterns and urban drainage. In recent years several studies have focused on revealing the nature, extent...... to urban drainage. However, in spite of these uncertainties, and others raised in the discussion, the tendency is clear: extreme precipitation events effecting urban drainage and causing flooding will become more frequent as a result of climate change....

  6. Hazards of volcanic lakes: analysis of Lakes Quilotoa and Cuicocha, Ecuador

    Directory of Open Access Journals (Sweden)

    G. Gunkel

    2008-01-01

    Full Text Available Volcanic lakes within calderas should be viewed as high-risk systems, and an intensive lake monitoring must be carried out to evaluate the hazard of potential limnic or phreatic-magmatic eruptions. In Ecuador, two caldera lakesLakes Quilotoa and Cuicocha, located in the high Andean region >3000 a.s.l. – have been the focus of these investigations. Both volcanoes are geologically young or historically active, and have formed large and deep calderas with lakes of 2 to 3 km in diameter, and 248 and 148 m in depth, respectively. In both lakes, visible gas emissions of CO2 occur, and an accumulation of CO2 in the deep water body must be taken into account.

    Investigations were carried out to evaluate the hazards of these volcanic lakes, and in Lake Cuicocha intensive monitoring was carried out for the evaluation of possible renewed volcanic activities. At Lake Quilotoa, a limnic eruption and diffuse CO2 degassing at the lake surface are to be expected, while at Lake Cuicocha, an increased risk of a phreatic-magmatic eruption exists.

  7. PASSIVE TREATMENT OF ACID ROCK DRAINAGE FROM A SUBSURFACE MINE

    Science.gov (United States)

    Acidic, metal-contaminated drainages are a critical problem facing many areas of the world. Acid rock drainage results when metal sulfide minerals, particularly pyrite, are oxidized by exposure to oxygen and water. The deleterious effects of these drainages on receiving streams a...

  8. Systematic review and meta-analysis of closed suction drainage versus non-drainage in primary hip arthroplasty.

    LENUS (Irish Health Repository)

    Kelly, Enda G

    2014-03-01

    The routine use of drains in surgery has been dogmatically instituted in some disciplines. Orthopaedic surgery is one such sub-speciality. The use of postoperative closed suction drainage in total hip arthroplasty (THA) has become increasingly controversial with multiple randomised control trials performed to assess the benefit to outcome in THA. The hypothesis of this systematic review is that closed suction drainage does not infer a benefit and increase transfusion requirements of primary total hip arthroplasty patients. A systematic review and meta-analysis was conducted adhering to the PRISMA guidelines. A search of the available literature was performed on PubMed, Cochrane Central Registry of Controlled Trials, MEDLINE (OVID) and EMBASE using a combination of MeSH terms and Boolean operators. All data analysis was performed using the Cochrane Collaboration\\'s Review Manager 5.1. Sixteen studies (n=2705) were included in the analysis. Post-operative closed suction drainage was found to increase total blood loss and blood transfusion requirements (p<0.05). Surgical site infection demonstrated no significant difference between the two groups (p=0.82). No significant difference in haematoma formation between groups (p=0.19) was elicited. The routine use of closed suction drainage systems post primary hip arthroplasty is not supported by this meta-analysis. However, the heterogeneity between studies does limit the accuracy of the meta-analysis.

  9. A model to measure lymphatic drainage from the eye.

    Science.gov (United States)

    Kim, Minhui; Johnston, Miles G; Gupta, Neeru; Moore, Sara; Yücel, Yeni H

    2011-11-01

    Intraocular pressure (IOP) is the most important risk factor for glaucoma development and progression. Most anti-glaucoma treatments aim to lower IOP by enhancing aqueous humor drainage from the eye. Aqueous humor drainage occurs via well-characterized trabecular meshwork (TM) and uveoscleral (UVS) pathways, and recently described ciliary body lymphatics. The relative contribution of the lymphatic pathway to aqueous drainage is not known. We developed a sheep model to quantitatively assess lymphatic drainage along with TM and UVS outflows. This study describes that model and presents our initial findings. Following intracameral injection of (125)I-bovine serum albumin (BSA), lymph was continuously collected via cannulated cervical lymphatic vessels and the thoracic lymphatic duct over either a 3-h or 5-h time period. In the same animals, blood samples were collected from the right jugular vein every 15 min. Lymphatic and TM drainage were quantitatively assessed by measuring (125)I-BSA in lymph and plasma, respectively. Radioactive tracer levels were also measured in UVS and "other" ocular tissue, as well as periocular tissue harvested 3 and 5 h post-injection. Tracer recovered from UVS tissue was used to estimate UVS drainage. The amount of (125)I-BSA recovered from different fluid and tissue compartments was expressed as a percentage of total recovered tracer. Three hours after tracer injection, percentage of tracer recovered in lymph and plasma was 1.64% ± 0.89% and 68.86% ± 9.27%, respectively (n = 8). The percentage of tracer in UVS, other ocular and periocular tissues was 19.87% ± 5.59%, 4.30% ± 3.31% and 5.32% ± 2.46%, respectively. At 5 h (n = 2), lymphatic drainage was increased (6.40% and 4.96% vs. 1.64%). On the other hand, the percentage of tracer recovered from UVS and other ocular tissue had decreased, and the percentage from periocular tissue showed no change. Lymphatic drainage increased steadily over the 3 h post-injection period, while TM

  10. Regulated Electric Drainage and its Interference with Track Circuits

    Directory of Open Access Journals (Sweden)

    Vaclav Kolar

    2018-01-01

    Full Text Available Electric drainage is a power electronic device used to protect underground metal devices (such as piping from the corrosive effects of stray currents. Stray currents are usually caused by DC electric traction, such as trams or railways. In places where stray currents leave the underground device and return into rails, they cause significant electrochemical corrosion of buried devices. The principle of electric drainage is based on electrical connection between the underground device and electric traction rails, which ensures that current flows through this connection, instead of flowing into the ground. Nowadays, the most widely used type is regulated electric drainage, where current is regulated by means of Pulse Width Modulation (PWM. Because of this modulation, current flowing through the drainage contains harmonic components with different frequencies. In modern railways, track circuits are often used as an important part of the track security system. For safe operation, it is necessary to ensure that frequencies generated by the drainage do not interfere with track circuits. This paper describes the design of a regulated drainage control system, with regard to its compatibility with track circuits and this paper contains related computer simulations and discussion of the results

  11. Radiologic guidance of drainage of infected and noninfected thoracic fluid collections

    International Nuclear Information System (INIS)

    Van Sonnenberg, E.; Casola, G.; Stavas, J.; Neff, C.C.; Wittich, G.R.; Varney, R.A.; Christensen, R.; Friedman, P.

    1987-01-01

    This exhibit illustrates the spectrum and benefits of radiologic guidance of drainage of 100 thoracic fluid collections. Collections which underwent drainage include: empyemas, lung abscesses, bronchopleural fistulas (BPF), mediastinal abscesses, paracardial collections, bronchogenic cysts, sequestrations, lymphocoeles, malignant effusions, and necrotic tumors. Sclerotherapy catheterization also is described. The modalities for guidance were CT, US, and fluoroscopy. Inadequate thoracostomy tube drainage occurred in a third of the patients prior to radiologic drainage. Drainages were effective in 85% of cases sparing surgery or another thoracostomy tube. Complications occurred in 7% of patients, most being minor and none requiring operation. Pitfalls and caveats are highlighted. Criteria for drainage of lung abscesses and BPF are emphasized, as are techniques and methods of follow-up

  12. Acid mine drainage

    Science.gov (United States)

    Bigham, Jerry M.; Cravotta, Charles A.

    2016-01-01

    Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage usually contains elevated concentrations of sulfate, iron, aluminum, and other potentially toxic metals leached from rock that hydrolyze and coprecipitate to form rust-colored encrustations or sediments. When AMD is discharged into surface waters or groundwaters, degradation of water quality, injury to aquatic life, and corrosion or encrustation of engineered structures can occur for substantial distances. Prevention and remediation strategies should consider the biogeochemical complexity of the system, the longevity of AMD pollution, the predictive power of geochemical modeling, and the full range of available field technologies for problem mitigation.

  13. Risk factors influencing the pleural drainage volume after transthoracic oesophagectomy.

    Science.gov (United States)

    Kosugi, Shin-ichi; Kanda, Tatsuo; Yajima, Kazuhito; Ishikawa, Takashi; Sakamoto, Kaoru

    2013-06-01

    The objective of this study was to clarify the factors influencing pleural drainage volume after transthoracic oesophagectomy and to determine criteria for the selection of patients who would benefit from the early removal of chest drains. Clinicopathological characteristics of 155 patients who underwent transthoracic oesophagectomy were prospectively collected, and the daily drainage volume of each patient was retrospectively reviewed. Potential risk factors were compared between the high-output group (n = 39) and low-output group (n = 116), which were dichotomized using the 75th percentile of total pleural drainage volume of the total study population. Multivariate logistic regression analyses were used to identify independent risk factors. The median duration of drainage was 10 days, with a median total drainage volume of 2258 ml. Of 27 potential risk factors influencing the drainage volume, creatinine clearance (P = 0.04), operative approach (P = 0.03) and thoracic duct removal (P = 0.01) were significantly associated with the total pleural drainage volume. The removal of the thoracic duct (P = 0.02; odds ratio, 4.02; 95% confidence interval 1.20-13.41) and lower creatinine clearance (P = 0.04; odds ratio, 1.02; 95% confidence interval 1.00-1.04) was independent risk factors for increased pleural drainage volume after transthoracic oesophagectomy. The early removal of chest drains may be possible in patients without these risk factors.

  14. Estimating the benefits of improved drainage on pavement ...

    African Journals Online (AJOL)

    user

    2 Centre for Transportation Systems, Indian Institute of Technology Roorkee, INDIA ... parking lots that only allow cars, not trucks). ..... drainage section) and 2015 & 2019 (for poor drainage section) after the construction of an overlay, it was ...

  15. Acid Mine Drainage Treatment

    National Research Council Canada - National Science Library

    Fripp, Jon

    2000-01-01

    .... Acid mine drainage (AMD) can have severe impacts to aquatic resources, can stunt terrestrial plant growth and harm wetlands, contaminate groundwater, raise water treatment costs, and damage concrete and metal structures...

  16. Agricultural Drainage Well Intakes

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Locations of surface intakes for registered agriculture drainage wells according to the database maintained by IDALS. Surface intakes were located from their...

  17. CT-guided biopsies and drainage

    International Nuclear Information System (INIS)

    Scheppers, I.; Wollschlaeger, D.

    2011-01-01

    Following the implementation of computed tomography (CT) or ultrasound-guided biopsy of solid tumors and the puncture and drainage of liquid processes, the number of surgical open biopsies and curative operations for abscess drainage has declined. Such CT-guided interventions are performed in nearly every organ. Instead of aspiration biopsies, more and more core biopsies are being performed to allow histopathological evaluation and thus allowing targeted therapy. This article is intended to give a general overview of techniques, materials, indications and contraindications. Ultrasound-guided biopsies as well as large bore vacuum biopsies of the breast are not included in this review. (orig.) [de

  18. Management of chest drainage tubes after lung surgery.

    Science.gov (United States)

    Satoh, Yukitoshi

    2016-06-01

    Since chest tubes have been routinely used to drain the pleural space, particularly after lung surgery, the management of chest tubes is considered to be essential for the thoracic surgeon. The pleural drainage system requires effective drainage, suction, and water-sealing. Another key point of chest tube management is that a water seal is considered to be superior to suction for most air leaks. Nowadays, the most common pleural drainage device attached to the chest tube is the three-bottle system. An electronic chest drainage system has been developed that is effective in standardizing the postoperative management of chest tubes. More liberal use of digital drainage devices in the postoperative management of the pleural space is warranted. The removal of chest tubes is a common procedure occurring almost daily in hospitals throughout the world. Extraction of the tube is usually done at the end of full inspiration or at the end of full expiration. The tube removal technique is not as important as how it is done and the preparation for the procedure. The management of chest tubes must be based on careful observation, the patient's characteristics, and the operative procedures that had been performed.

  19. Drainage from coal mines: Chemistry and environmental problems

    International Nuclear Information System (INIS)

    Wildeman, T.

    1991-01-01

    Much of the research on coal-mine drainage chemistry was conducted a decade ago, and now increased environmental awareness has brought about renewed interest in the findings. Consideration of the trace minerals and elements in coal points to the possible generation of acidic waters upon weathering, especially when pyrite is present. When pyrite weathers, it produces H + and Fe 3+ which catalyze the incongruent weathering of other carbonates and sulfides. In this weathering mechanism, catalysis by bacteria is important. Of the environmental problems in coal mine drainage, the mineral acidity of the water is the most serious. This is caused not only by the H + , but also by Mn 4+ , Fe 3+ , and Al 3+ that are found or generated within the drainage. Case studies in Kentucky, Pennsylvania, Illinois, and Colorado show that the abundance and form of pyrite in the deposit and in the overburden determines the level of acidity and the concentration of heavy metal pollutants in the drainage. Recent trends in environmental enforcement that emphasize integrated stream water standards and biotoxicity assays point to the possibility that the concentrations of heavy metals in coal mine drainages may cause environmental concern

  20. Subsurface irrigation of potato crop (Solanum tuberosum ssp. Andigena) in Suka Kollus with different drainage systems

    Science.gov (United States)

    Serrano-Coronel, Genaro; Chipana-Rivera, René; Fátima Moreno-Pérez, María; Roldán-Cañas, José

    2016-04-01

    Among the most important hydraulic structures of pre-Hispanic ancestral technology developed in the Andean region, we find the suka kollus, aymara word, called also waru waru, en quechua or raised fields, in English. They are raised platforms surrounded by water canals that irrigate subsurface, but also have the function of draining, to deal with floods because they are surrounding Lake Titicaca. They also have the property of generating a thermoregulatory effect to crops, depending on the configuration of the channels and platforms. Such agro-ecosystems are being abandoned, however, if properly addressed crop management and some drainage canals are replaced by underground drains for increased crop area could be very useful in enabling marginal soils affected by salts and / or excess water. For these reasons, the objective of this study was to evaluate the subsurface irrigation in the potato crop in suka kollus under a system of surface drainage, and mixed drainage (surface and subsurface). The study was conducted in marginal soils of Kallutaca area, located 30 km from the city of La Paz, Bolivia, at a height of 3892 m.a.s.l. The cultivation of the potato (Solanum tuberosum ssp. Andigena) was used. Four treatments were tested with different widths of the platforms: T1 (Control) with drainage through channels; T2 (replacing a channel by a drain); T3 (replacing two channels by two drains); T4 (replacing three channels by three drains). The flow of water into the soil from the water table was predominantly upward, except during periods of high rainfall. In terms of treatments, the flow in T1 was higher, mainly at weeks 8 to 11 after seedling emergence, coinciding with the phenological phases of flowering and at the beginning of the tuber ripening. It was followed by T3, T2 and T4 treatments, respectively. Tuber yield, if one considers that the channels detract arable land, was higher in the T3 treatment,16.4 Mg / ha, followed by T2 treatment, 15.2 Mg / ha, T1

  1. Glaucoma Drainage Device Erosion Following Ptosis Surgery.

    Science.gov (United States)

    Bae, Steven S; Campbell, Robert J

    2017-09-01

    To highlight the potential risk of glaucoma drainage device erosion following ptosis surgery. Case report. A 71-year-old man underwent uncomplicated superotemporal Ahmed glaucoma valve implantation in the left eye in 2008. Approximately 8 years later, the patient underwent bilateral ptosis repair, which successfully raised the upper eyelid position. Three months postoperatively, the patient's glaucoma drainage implant tube eroded through the corneal graft tissue and overlying conjunctiva to become exposed. A graft revision surgery was successfully performed with no further complications. Caution and conservative lid elevation may be warranted when performing ptosis repair in patients with a glaucoma drainage implant, and patients with a glaucoma implant undergoing ptosis surgery should be followed closely for signs of tube erosion.

  2. Principles of lake sedimentology

    International Nuclear Information System (INIS)

    Janasson, L.

    1983-01-01

    This book presents a comprehensive outline on the basic sedimentological principles for lakes, and focuses on environmental aspects and matters related to lake management and control-on lake ecology rather than lake geology. This is a guide for those who plan, perform and evaluate lake sedimentological investigations. Contents abridged: Lake types and sediment types. Sedimentation in lakes and water dynamics. Lake bottom dynamics. Sediment dynamics and sediment age. Sediments in aquatic pollution control programmes. Subject index

  3. Characteristics and ontogeny of oligotrophic hardwater lakes in the Forsmark area, central Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Brunberg, A.K.; Blomqvist, P. [Uppsala Univ. (Sweden). Dept. of Limnology

    1999-12-01

    colonise the littoral, and a mire is formed around the lake. In later stages of succession, Sphagnum becomes more and more dominant in the system, which successively turns acidic. The final stage of the ontogeny is likely to be a raised bog ecosystem with an autonomous hydrological functioning. A tentative model for a mature hardwater lake has been created, indicating how and where substances from the drainage area may be accumulated in the system. Depending on the (unknown) hydrology of the lake basin, accumulation of substances can either take place in the Sphagnum littoral, in the illuminated soft-bottom sediments or in both these habitats. Processes in the open water will be of less importance in the system, since production of organisms in that habitat is most likely low. However, fish may act as a pump for nutrients and organic matter between the soft-bottom and the open water habitats, thereby disturbing the accumulation of substances in the sediments. In conclusion, several pieces are lacking to complete the picture of the structure and functioning of the ecosystem in the oligotrophic hardwater lakes of the Forsmark area. Research directed towards the understanding of the lakes as a trap for contaminants should be focused on the hydrology of the basin and on the basal production in two of the key habitats; the mire/floating littoral system and the 'microbial mat' in the light exposed soft bottom areas.

  4. Characteristics and ontogeny of oligotrophic hardwater lakes in the Forsmark area, central Sweden

    International Nuclear Information System (INIS)

    Brunberg, A.K.; Blomqvist, P.

    1999-12-01

    colonise the littoral, and a mire is formed around the lake. In later stages of succession, Sphagnum becomes more and more dominant in the system, which successively turns acidic. The final stage of the ontogeny is likely to be a raised bog ecosystem with an autonomous hydrological functioning. A tentative model for a mature hardwater lake has been created, indicating how and where substances from the drainage area may be accumulated in the system. Depending on the (unknown) hydrology of the lake basin, accumulation of substances can either take place in the Sphagnum littoral, in the illuminated soft-bottom sediments or in both these habitats. Processes in the open water will be of less importance in the system, since production of organisms in that habitat is most likely low. However, fish may act as a pump for nutrients and organic matter between the soft-bottom and the open water habitats, thereby disturbing the accumulation of substances in the sediments. In conclusion, several pieces are lacking to complete the picture of the structure and functioning of the ecosystem in the oligotrophic hardwater lakes of the Forsmark area. Research directed towards the understanding of the lakes as a trap for contaminants should be focused on the hydrology of the basin and on the basal production in two of the key habitats; the mire/floating littoral system and the 'microbial mat' in the light exposed soft bottom areas

  5. Dynamic drainage of froth with wood fibers

    Science.gov (United States)

    J.Y. Zhu; Freya Tan

    2005-01-01

    Understanding froth drainage with fibers (or simply called fiber drainage in froth) is important for improving fiber yield in the flotation deinking operation. In this study, the data of water and fiber mass in foams collected at different froth heights were used to reconstruct the time dependent and spatially resolved froth density and fiber volumetric concentration...

  6. Intermediate-term and long-term outcome of piggyback drainage: connecting glaucoma drainage device to a device in-situ for improved intraocular pressure control.

    Science.gov (United States)

    Dervan, Edward; Lee, Edward; Giubilato, Antonio; Khanam, Tina; Maghsoudlou, Panayiotis; Morgan, William H

    2017-11-01

    This study provides results of a treatment option for patients with failed primary glaucoma drainage device. The study aimed to describe and evaluate the long-term intraocular pressure control and complications of a new technique joining a second glaucoma drainage device directly to an existing glaucoma drainage device termed 'piggyback drainage'. This is a retrospective, interventional cohort study. Eighteen eyes of 17 patients who underwent piggyback drainage between 2004 and 2013 inclusive have been studied. All patients had prior glaucoma drainage device with uncontrolled intraocular pressure. The piggyback technique involved suturing a Baerveldt (250 or 350 mm) or Molteno3 glaucoma drainage device to an unused scleral quadrant and connecting the silicone tube to the primary plate bleb. Failure of intraocular pressure control defined as an intraocular pressure greater than 21 mmHg on maximal therapy on two separate occasions or further intervention to control intraocular pressure. The intraocular pressure was controlled in seven eyes (39%) at last follow-up with a mean follow-up time of 74.2 months. The mean preoperative intraocular pressure was 27.1 mmHg (95% confidence interval 23.8-30.3) compared with 18.4 mmHg (95% confidence interval 13.9-22.8) at last follow-up. The mean time to failure was 57.1 months (95% confidence interval 32.2-82), and the mean time to further surgery was 72.3 months (95% confidence interval 49.9-94.7). Lower preoperative intraocular pressure was associated with longer duration of intraocular pressure control (P = 0.048). If the intraocular pressure was controlled over 2 years, it continued to be controlled over the long term. Two eyes (11%) experienced corneal decompensation. Piggyback drainage represents a viable surgical alternative for the treatment of patients with severe glaucoma with failing primary glaucoma drainage device, particularly in those at high risk of corneal decompensation. © 2017 Royal Australian and New Zealand

  7. Responses of phytoplankton upon exposure to a mixture of acid mine drainage and high levels of nutrient pollution in Lake Loskop, South Africa.

    CSIR Research Space (South Africa)

    Oberholster, Paul J

    2009-01-01

    Full Text Available ¼ 5001–25,000 cells l�1. Equi- librial phytoplankton species (sensu Naselli-Flores et al., 2003) in the main lake basin (lacustrine zone, sampling sites 4 and 5) were determined over the study period of 6 months, using the following criteria: (1) 1, 2... of the phytoplankton community for this period, indicating that it was an ‘‘equilibrial species’’ (sensu Naselli-Flores et al., 2003). 3.3. Responses of S. capricornutum bioassay Water samples collected in the riverine zone (sites 1 and 2) of Lake Loskop were found...

  8. Lake Afdera: a threatened saline lake in Ethiopia | Getahun | SINET ...

    African Journals Online (AJOL)

    Lake Afdera is a saline lake located in the Afar region, Northern Ethiopia. Because of its inaccessibility it is one of the least studied lakes of the country. It supports life including three species of fish of which two are endemic. Recently, reports are coming out that this lake is used for salt extraction. This paper gives some ...

  9. Streamflow distribution maps for the Cannon River drainage basin, southeast Minnesota, and the St. Louis River drainage basin, northeast Minnesota

    Science.gov (United States)

    Smith, Erik A.; Sanocki, Chris A.; Lorenz, David L.; Jacobsen, Katrin E.

    2017-12-27

    Streamflow distribution maps for the Cannon River and St. Louis River drainage basins were developed by the U.S. Geological Survey, in cooperation with the Legislative-Citizen Commission on Minnesota Resources, to illustrate relative and cumulative streamflow distributions. The Cannon River was selected to provide baseline data to assess the effects of potential surficial sand mining, and the St. Louis River was selected to determine the effects of ongoing Mesabi Iron Range mining. Each drainage basin (Cannon, St. Louis) was subdivided into nested drainage basins: the Cannon River was subdivided into 152 nested drainage basins, and the St. Louis River was subdivided into 353 nested drainage basins. For each smaller drainage basin, the estimated volumes of groundwater discharge (as base flow) and surface runoff flowing into all surface-water features were displayed under the following conditions: (1) extreme low-flow conditions, comparable to an exceedance-probability quantile of 0.95; (2) low-flow conditions, comparable to an exceedance-probability quantile of 0.90; (3) a median condition, comparable to an exceedance-probability quantile of 0.50; and (4) a high-flow condition, comparable to an exceedance-probability quantile of 0.02.Streamflow distribution maps were developed using flow-duration curve exceedance-probability quantiles in conjunction with Soil-Water-Balance model outputs; both the flow-duration curve and Soil-Water-Balance models were built upon previously published U.S. Geological Survey reports. The selected streamflow distribution maps provide a proactive water management tool for State cooperators by illustrating flow rates during a range of hydraulic conditions. Furthermore, after the nested drainage basins are highlighted in terms of surface-water flows, the streamflows can be evaluated in the context of meeting specific ecological flows under different flow regimes and potentially assist with decisions regarding groundwater and surface

  10. Treatment of dyeing drainage by radiation

    International Nuclear Information System (INIS)

    Shimokawa, Toshinari; Sawai, Takeshi

    1985-01-01

    Decolorization of artificial dyeing drainage and sewage by radiation treatment. Artifical dyeing drainage was prepared from water, polyvinyl alcohol, starch, urea and several kinds of inorganic salts, and artificial sewage, from water, peptone, broth, urea and several kinds of inorganic salts. The above mentioned sample liquors of artificial dyeing drainage and sewage were exposed to γ-radiation of 5 kCi of 60 Co source by aerating through a ball filter. Absorption spectra, total organic carbon (TOC) and chemical oxygen demand (COD) were determined after irradiation to evaluate radiation treatment effect. With the experimental data obtained, it was clarified that absorbance, COD and TOC was decreased with the increase of absorbed dose. Decoloring was made effectively and about 95 % of bleaching ratio was obtained at 5 kGy of radiation. COD was decreased also by irradiation rather slower decreasing rate than that of decolorization, and TOC decrease was very slow at the initial stage of radiation but 40 % of TOC was decomposed by 10 kGy radiation. Dye of chemically stable structure was found more resistant to radiation decolorization. Decomposition efficiency was found less for dyes in the artificial sewage but secondary treated sewage showed no adverse effect. With the obtained understandings, a tentative scheme was planned for the radiation decolorization of dyeing drainage after aeration treatment. (Takagi, S.)

  11. Preoperative biliary drainage for pancreatic cancer.

    Science.gov (United States)

    Van Heek, N T; Busch, O R; Van Gulik, T M; Gouma, D J

    2014-04-01

    This review is to summarize the current knowledge about preoperative biliary drainage (PBD) in patients with biliary obstruction caused by pancreatic cancer. Most patients with pancreatic carcinoma (85%) will present with obstructive jaundice. The presence of toxic substances as bilirubin and bile salts, impaired liver function and altered nutritional status due to obstructive jaundice have been characterized as factors for development of complications after surgery. Whereas PBD was to yield beneficial effects in the experimental setting, conflicting results have been observed in clinical studies. The meta-analysis from relative older studies as well as more importantly a recent clinical trial showed that PBD should not be performed routinely. PBD for patients with a distal biliary obstruction is leading to more serious complications compared with early surgery. Arguments for PBD have shifted from a potential therapeutic benefit towards a logistic problem such as patients suffering from cholangitis and severe jaundice at admission or patients who need extra diagnostic tests, or delay in surgery due to a referral pattern or waiting list for surgery as well as candidates for neoadjuvant chemo(radio)therapy. If drainage is indicated in these patients it should be performed with a metal stent to reduce complications after the drainage procedure such as stent occlusion and cholangitis. Considering a change towards more neoadjuvant therapy regimes improvement of the quality of the biliary drainage concept is still important.

  12. Water quality of Lake Austin and Town Lake, Austin, Texas

    Science.gov (United States)

    Andrews, Freeman L.; Wells, Frank C.; Shelby, Wanda J.; McPherson, Emma

    1988-01-01

    Lake Austin and Town Lake are located on the Colorado River in Travis County, central Texas, and serve as a source of water for municipal and industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Lake Austin, located immediately downstream of Lake Travis, extends for more than 20 miles into the western edge of the city of Austin. Town Lake extends through the downtown area of the city of Austin for nearly 6 miles where the Colorado River is impounded by Longhorn Dam.

  13. Role of Lithology and Rock Structure in Drainage Development in ...

    African Journals Online (AJOL)

    Lithology and Rock structure play a vital role in the development of Drainage Network in any drainage basin. The drainage patterns upon land surface develop as directed by the underlying lithology and rock structure. In fact, lithology and rock structure together shape the basin and are decisive parameters of nature and ...

  14. Gravitational shunt units may cause under-drainage in bedridden patients.

    Science.gov (United States)

    Kaestner, S; Kruschat, T; Nitzsche, N; Deinsberger, W

    2009-03-01

    Implantation of a shunt in a hydrocephalic patient still carries a risk of complications such as over-drainage and under-drainage. Gravitational shunt units are especially designed to minimize the problem of over-drainage. Nevertheless, these valves carry a risk of under-drainage. The best choice of valve for a patient is still challenging. The purpose of this survey was to identify in which patients a gravitational shunt valve is liable to lead to under-drainage. Patients with hydrocephalus entered prospectively into a data base were reviewed retrospectively. The patients were treated between January 2006 to the end of Feb 2007 and those experiencing under- or over-drainage were identified. Thirty-five ventriculo-peritoneal shunt systems were implanted in adult patients. The cause of the hydrocephalus was: normal pressure hydrocephalus in 18 patients, post-haemorrhagic following subarachnoid or intracerebral haemorrhage in 11, associated with a tumour in four and followed a head injury in two patients. Three different valves were used: an adjustable shunt valve with gravitational unit (Pro-GAV 0-20/25 in 21 patients), a gravitational shunt valve with fixed opening pressure (GAV 5/30 in nine patients) and an adjustable differential valve (Hakim medos in five patients). Four patients developed severe, valve-related under-drainage. Each had received a gravitational shunt valve and all were bedridden. In two of these patients it was necessary to change the valve. One patient who had received a differential valve, after regaining mobility developed severe over-drainage with bilateral subdural haematomas. Over-drainage was not seen in long-term bedridden patients with a differential shunt valve. If a bedridden patient with a gravitational shunt valve system lies with a slightly elevated head, this leads to activation of the gravitational unit and this may cause under drainage. As a result, we advise not using an anti-siphon devices in a patient who is bedridden for a

  15. Ultrasound-guided percutaneous transhepatic biliary drainage: Experiences in 146 patients

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jai Keun [Sohwa Children' s Hospital, Seoul(Korea, Republic of); Yu, Jeong Sik; Kim, Ki Whang; Chung, Soo Yoon; Jeong, Mi Gyoung [Yonsei University College of Medicine, Seoul (Korea, Republic of); Choi, Deuk Lin; Kwon, Gui Hyang; Lee, Hae Kyung [Soonchunhyang University College of Medicine, Seoul (Korea, Republic of)

    1999-03-15

    Percutaneous biliary drainage is an important technique for palliative therapy of obstructive biliary disease and diagnostic information. The purpose of this study is to review and evaluate the experiences of ultrasound-guided percutaneous transhepatic biliary drainage. Ultrasound-guided percutaneous transhepatic biliary drainage was performed on 146 occasions in 134 patients. The causes of biliary obstruction were: benign diseases (19 cases, 14.2%) such as bile duct stones or stricture, cholangiocarcinoma (37 cases, 27.6%), pancreatic carcinoma (35 cases, 26.1%), metastasis (22 cases, 16.5%), gall bladder cancer (14 cases, 10.4%), ampulla of Vater cancer (4 cases, 3.0%), hepatocellular carcinoma (3 cases, 2.2%). Retrospectively reviewing medical records, we found out frequency of external or external/internal biliary drainages, puncture of left or right hepatic duct, and presence of bileinfection. Ultrasound-guided percutaneous transhepatic biliary drainage was compared with conventional biliary drainage of previous reports on the basis of frequency of complications. External (124 procedures, 84.9%) and external/internal biliary drainage (22 procedures, 15.1%) were carried out by puncture of dilated right (59.6%) or left (40.4%) intrahepatic duct. Sixty-nine complications occurred in 47 patients. Catheter related complications (33/69, 47.8%) were most common: catheter dislodgement (17/69, 24.6%), malfunction (9/69, 13.1%), leakage (7/69, 10.1%). Other minor complications such as simple fever (16/69, 23.2%), cholangitis (7/69, 10.1%), hemobilia (4/69, 5.8%), biloma (2/69, 2.9%) and wound infection (1/69, 1.5%) occurred. Major complications including sepsis (4/69, 5.8%) and bile peritonitis (2/69, 2.9%) were also noted. Puncture-related complications such as hemobilia, biloma and bile peritonitis occurred in 8 cases (5.5%). Comparing with conventional X-ray guided drainage, ultrasound-guided percutaneous transhepatic biliary drainage is a safe procedure for

  16. Refuge Lake Reclassification in 620 Minnesota Cisco Lakes under Future Climate Scenarios

    Directory of Open Access Journals (Sweden)

    Liping Jiang

    2017-09-01

    Full Text Available Cisco (Coregonus artedi is the most common coldwater stenothermal fish in Minnesota lakes. Water temperature (T and dissolved oxygen (DO in lakes are important controls of fish growth and reproduction and likely change with future climate warming. Built upon a previous study, this study uses a modified method to identify which of 620 cisco lakes in Minnesota can still support cisco populations under future climate and therefore be classified as cisco refuge lakes. The previous study used oxythermal stress parameter TDO3, the temperature at DO of 3 mg/L, simulated only from deep virtual lakes to classify 620 cisco lakes. Using four categories of virtual but representative cisco lakes in modified method, a one-dimensional water quality model MINLAKE2012 was used to simulate daily T and DO profiles in 82 virtual lakes under the past (1961–2008 and two future climate scenarios. A multiyear average of 31-day largest TDO3 over variable benchmark (VB periods, AvgATDO3VB, was calculated from simulated T and DO profiles using FishHabitat2013. Contour plots of AvgATDO3VB for four categories of virtual lakes were then developed to reclassify 620 cisco lakes into Tier 1 (AvgATDO3VB < 11 °C or Tier 2 refuge lakes, and Tier 3 non-refuge lakes (AvgATDO3VB > 17 °C. About 20% of 620 cisco lakes are projected to be refuge lakes under future climate scenarios, which is a more accurate projection (improving the prediction accuracy by ~6.5% from the previous study since AvgATDO3VB was found to vary by lake categories.

  17. Endoscopic Ultrasound-guided Drainage of Pancreatic Pseudocysts

    DEFF Research Database (Denmark)

    Ng, Pui Yung; Nytoft Rasmussen, Ditlev; Vilmann, Peter

    2013-01-01

    or by telephonic interview. RESULTS: A total of 61 procedures were performed. The symptoms that indicated drainage were abdominal pain (n = 43), vomiting (n = 7) and jaundice (n = 5). The procedure was technically successful in 57 of the 61 procedures (93%). The immediate complication rate was 5%. At a mean follow......-up of 45 weeks, the treatment success was 75%. The medium term complications appeared in 25% of cases, which included three cases each of stent clogging, stent migration, infection and six cases of recurrence. There was no mortality. CONCLUSION: EUS-guided drainage is an effective treatment for PPC...... with a successful outcome in most of patients. Most of the complications require minimal invasive surgical treatment or repeated EUS-guided drainage procedures....

  18. Profile of thoracic trauma victims submitted to chest drainage

    Directory of Open Access Journals (Sweden)

    CESAR AUGUSTO BROSKA JÚNIOR

    Full Text Available ABSTRACT Objective: to describe and compare the variables involved in trauma victims undergoing thoracic drainage. Methods: we conducted a retrospective, analytical, descriptive, cross-sectional study, with medical records of patients attended at the Trauma Service of the Curitiba Evangelical University Hospital between February 2011 and January 2014. Results: there were 488 patients undergoing chest drainage, 84.7% men and 15.3% women, with an average age of 38.2 years. Attendances usually occurred at night, without predominance between open or closed mechanism, gender or age group. The majority of patients with thoracic trauma requiring drainage were diagnosed by anamnesis and physical examination (41.1% and drained in the emergency room (