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Sample records for fluctuating water levels

  1. Wii mote as hydrological sensor: observation of water level fluctuations

    Science.gov (United States)

    Luxemburg, W.; Hut, R.; Weijs, S.; Hegnauer, M.

    2009-12-01

    The input device of the Nintendo Wii, the Wii-mote offers scientist a multitude of cheap, high quality sensors; ideal for proof of concept testing. For a specific application, i.e. the water level fluctuation in a floating evaporation pan the Wii-mote was tested as the observing device. It is shown that the controller can observe movements with high enough temporal and spatial resolution of up to 4 infrared LED’s to describe water level movements. Floating pans positioned in lakes and reservoirs better represent open water evaporation than evaporation pans installed on land. On the other hand performing water level measurements in a floating pan is more complicated due to movement of the pan and wave activities in the pan. The Wii-mote was mounted on the side of a standard class A-pan and a float was placed in the middle of the pan, with 4 LED’s on top moving along a fixed bar. The information that the Wii-mote wirelessly sends by blue tooth was captured on a laptop. With a MATLAB routine this data was converted into movement of the LED’s relatively to the controller. The observations show that wave activities are nicely captured with a typical spatial resolution smaller than 0.1 mm in our set-up and a temporal resolution of maximum 100 Hz. A frequency domain filter was applied to the observed datasets to obtain average water levels. In our laboratory setting the pan was placed in a large basin with a wave generator. A constant, but small, rate of water was added to the evaporation pan. The average pan levels from the filtered datasets showed systematically lower levels compared to the level without any wave activities. This is a typical effect of waves that occur in shallow basins. However, the added water with rates up to 5 mm/hour were clearly recognized in the filtered datasets which indicates that the Wii-mote is very well capable as a sensor for water level observations.

  2. Water level fluctuations due to earth tides in a well pumping from slightly fractured crystalline rock

    International Nuclear Information System (INIS)

    J At the Savannah River plant of the Atomic Energy Commission near Aiken, South Carolina, there are three distinct groundwater systems: the coastal plain sediments, the crystalline metamorphic rocks, and a buried Triassic basin. The coastal plain sediments include several Cretaceous and Tertiary granular aquifers and aquicludes, the total thickness being about 305 m. Below these sediments, water occurs in small fractures in crystalline metamorphic rock (hornblende schist and gneiss with lesser amounts of quartzite). Water level fluctuations due to earth tides are recorded in the crystalline metamorphic rock system and in the coastal plain sediments. No water level fluctuations due to earth tides have been observed in wells in the Triassic rock because of the very low permeability. The water level fluctuations due to earth tides in the crystalline rock are about 10 cm, and those in the sediments are about 1.8 cm. The use of water level fluctuations due to earth tides to calculate porosity appears to present practical difficulties both in the crystalline metamorphic rock system and in the coastal plain sediments. In a 1-yr pumping test on a well in the crystalline metamorphic rock the flow was controlled to within 0.1 percent of the total discharge, which was 0.94 1/s. The water level fluctuations due to earth tides in the pumping well were 10 cm, the same as when this well was not being pumped. (U.S.)

  3. Spectral analysis of observed aquifer water level fluctuations

    Science.gov (United States)

    McLin, Stephen

    2012-09-01

    A mathematical model is presented that describes small, periodic, water level perturbations in a fully screened observation well penetrating a homogeneous, isotropic, confined aquifer system. The analytical solution is formulated in terms of frequency and phase response functions that are controlled by aquifer transmissivity (T) and storage coefficient (S). Well casing storage effects are considered; however, well screen entrance losses associated with turbulence are neglected because piezometric head differences inside and outside the well are small. As the ratio of well casing radius to well screen radius (rc/rw) changes, these theoretical response functions are systematically altered. When rc/rwsigmoidal curve fitting algorithm and observed frequency and phase response functions are used to identify a starting estimate for T. This value is then used in the LM procedure and facilitates convergence to optimal system parameters while minimizing uncertainty. Without this approach, however, the LM scheme will not yield unique estimates. This methodology yields smaller aquifer parameters than traditional specific capacity tests, suggesting either a well bore skin effect or a scaling phenomenon similar to that reported in the literature for slug and aquifer test comparisons. Hence, this technique is probably best suited for monitoring wells where conventional aquifer test methods are impractical. This approach is documented in several MATLAB m-files and illustrated by several examples using observed data.

  4. Pleiades and radar imagery in tracking water level fluctuations in reservoirs

    OpenAIRE

    Simon, R. N.; Tormos, T.; Danis, P. A.

    2014-01-01

    Tracking water level fluctuations is important to the study and management of waterbodies. A geographic object-based image analysis using very high spatial and temporal radar interferometry (Cosmo-Skymed and TerraSAR-X) and optical (Pléiades) imagery is adopted in this study for this purpose. A linear regression model was sufficient to correlate the water surface area of a mildly sloping and unencumbered littoral zone spatial subset (extracted from 14 images) to water surface altitude data f...

  5. A Hydro-Economic Model for Water Level Fluctuations: Combining Limnology with Economics for Sustainable Development of Hydropower

    OpenAIRE

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines...

  6. Earthquake-induced water-level fluctuations at Yucca Mountain, Nevada, June 1992

    International Nuclear Information System (INIS)

    This report presents earthquake-induced water-level and fluid-pressure data for wells in the Yucca Mountain area, Nevada, during June 1992. Three earthquakes occurred which caused significant water-level and fluid-pressure responses in wells. Wells USW H-5 and USW H-6 are continuously monitored to detect short-term responses caused by earthquakes. Two wells, monitored hourly, had significant, longer-term responses in water level following the earthquakes. On June 28, 1992, a 7.5-magnitude earthquake occurred near Landers, California causing an estimated maximum water-level change of 90 centimeters in well USW H-5. Three hours later a 6.6-magnitude earthquake occurred near Big Bear Lake, California; the maximum water-level fluctuation was 20 centimeters in well USW H-5. A 5.6-magnitude earthquake occurred at Little Skull Mountain, Nevada, on June 29, approximately 23 kilometers from Yucca Mountain. The maximum estimated short-term water-level fluctuation from the Little Skull Mountain earthquake was 40 centimeters in well USW H-5. The water level in well UE-25p number-sign 1, monitored hourly, decreased approximately 50 centimeters over 3 days following the Little Skull Mountain earthquake. The water level in UE-25p number-sign 1 returned to pre-earthquake levels in approximately 6 months. The water level in the lower interval of well USW H-3 increased 28 centimeters following the Little Skull Mountain earthquake. The Landers and Little Skull Mountain earthquakes caused responses in 17 intervals of 14 hourly monitored wells, however, most responses were small and of short duration. For several days following the major earthquakes, many smaller magnitude aftershocks occurred causing measurable responses in the continuously monitored wells

  7. Establishment of earth tides effect on water level fluctuations in an unconfined hard rock aquifer using spectral analysis

    CERN Document Server

    Maréchal, Jean-Christophe; Ahmed, Shakeel; Lachassagne, Patrick

    2010-01-01

    Short-interval water level measurements using automatic water level recorder in a deep well in an unconfined crystalline rock aquifer at the campus of NGRI, near Hyderabad shows a cyclic fluctuation in the water levels. The observed values clearly show the principal trend due to rainfall recharge. Spectral analysis was carried out to evaluate correlation of the cyclic fluctuation to the synthetic earth tides as well as groundwater withdrawal time series in the surrounding. It was found that these fluctuations have considerably high correlation with earth tides whereas groundwater pumping does not show any significant correlation with water table fluctuations. It is concluded that earth tides cause the fluctuation in the water table. These fluctuations were hitherto unobserved during manual observations made over larger time intervals. It indicates that the unconfined aquifer is characterised by a low porosity.

  8. Response of littoral macrophytes to water level fluctuations in a storage reservoir

    Directory of Open Access Journals (Sweden)

    Krolová M.

    2013-05-01

    Full Text Available Lakes and reservoirs that are used for water supply and/or flow regulations have usually poorly developed littoral macrophyte communities, which impairs ecological potential in terms of the EU Water Framework Directive. The aim of our study was to reveal controlling factors for the growth of littoral macrophytes in a storage reservoir with fluctuating water level (Lipno Reservoir, Czech Republic. Macrophytes occurred in this reservoir only in the eulittoral zone i.e., the shoreline region between the highest and the lowest seasonal water levels. Three eulittoral sub-zones could be distinguished: the upper eulittoral with a stable community of perennial species with high cover, the middle eulittoral with relatively high richness of emergent and amphibious species present at low cover values, and the lower eulittoral devoid of permanent vegetation. Cover and species composition in particular sub-zones were primarily influenced by the duration and timing of flooding, followed by nutrient limitation and strongly reducing conditions in the flooded organic sediment. Our results stress the ecological importance of eulittoral zone in reservoirs with fluctuating water levels where macrophyte growth can be supported by targeted management of water level, thus helping reservoir managers in improving the ecological potential of this type of water bodies.

  9. A hydro-economic model for water level fluctuations: combining limnology with economics for sustainable development of hydropower.

    Science.gov (United States)

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity). Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands. PMID:25526619

  10. Response of littoral macrophytes to water level fluctuations in a storage reservoir.

    Czech Academy of Sciences Publication Activity Database

    Krolová, Monika; ?ížková, Hana; Hejzlar, Josef; Poláková, S.

    2013-01-01

    Ro?. 408, May (2013), 07p1-07p21. ISSN 1961-9502 R&D Projects: GA ?R(CZ) GA206/09/1764; GA MŠk(CZ) 7E11059 Grant ostatní: EC ENV(CZ) FP7 244121 Institutional research plan: CEZ:AV0Z60170517 Institutional support: RVO:60077344 ; RVO:67179843 Keywords : littoral macrophytes * eulittoral * water level fluctuation * European Water Framework Directive * ecophases Subject RIV: DA - Hydrology ; Limnology Impact factor: 0.622, year: 2013

  11. Earthquake-induced water-level fluctuations at Yucca Mountain, Nevada, April 1992

    International Nuclear Information System (INIS)

    This report presents earthquake-induced water-level and fluid- pressure data for well USW H-5 during April 1992. Well USW H-5 is located in the Yucca Mountain area, Nevada. On April 22,1992 a 6.2-magnitude earthquake occurred in southern California which caused a maximum fluid-pressure change of approximately 50 centimeters in well USW H-5. Within 18 hours on April 25--26, 1992, three major earthquakes occurred in northern California. The water-level responses to these earthquakes were detected in well USW H-5. The maximum water-level fluctuation from the northern California earthquakes was in excess of 52.5 cm

  12. Recurrent Water Level Fluctuation Alleviates the Effects of Submergence Stress on the Invasive Riparian Plant Alternanthera philoxeroides

    Science.gov (United States)

    Zhang, Haijie; Wang, Renqing; Wang, Xiao; Du, Ning; Ge, Xiuli; Du, Yuanda; Liu, Jian

    2015-01-01

    Recurrent water level fluctuation and submergence of plants are common in riparian zones. Our study objectives were to test the independent and interactive effects of submergence level and fluctuation frequency on a globally important riparian invasive plant, Alternanthera philoxeroides. To this end, we conducted a greenhouse experiment, in which ramets of the plants, obtained from a wetland in China, were treated with four fluctuation frequencies (0, 3, 6, and 12 cycles over a 96-day experimental period) under three water levels (0, 10, and 30 cm). We found that effects of fluctuation frequency were non-significant, negative, and positive under water levels of 0, 10 and 30 cm, respectively. As fluctuation frequency increased, the effects of increasing water level decreased significantly. When water levels were high, A. philoxeroides allocated greater biomass to shoot production probably in order to elongate and escape from submergence. However, as fluctuation frequency increased, biomass investment in roots and leaves also increased, probably in order to maximize nutrient absorption and photosynthesis, respectively. These results suggest that water level fluctuation may alleviate the effects of submergence on A. philoxeroides. In addition, A. philoxeroides showed significant phenotypic plasticity, adjusting its functional traits, such as number of nodes and leaves per stem, as well as stem diameter and pith cavity diameter, according to recurrent water level fluctuation. We conclude that A. philoxeroides may perform better in shallow water zones under conditions of disturbance that include recurrent water level fluctuation. This ability to adapt to disturbance likely promotes its growth and invasion in disturbed habitats. PMID:26066509

  13. Water-level fluctuation and its implication on the hydrologic cycle in the Gwangneung Supersite, Korea

    Science.gov (United States)

    Kim, Y.; Woo, N.; Hong, T.; Kim, J.

    2007-12-01

    For effective assessment and management of water resources, it is important to understand and quantify each component of the hydrologic cycle. A careful and detailed analysis of spatio-temporal variations in water levels in aquifers could reveal useful information on the groundwater system. This study is objected to understand the reasons and mechanisms of fluctuations. As a part of an interdisciplinary research project, HydroKorea, to ascertain the water cycle quantitatively, water levels have been monitored from shallow monitoring wells(G1, G4) with less than 1-m in depths and a deep well enclosing three monitoring wells (ft1, ft2 and ft3 screened at depths of 102m, 45m and 6m below ground surface, respectively). Monitoring wells are located in the Gwangneung Supersite, Korea. Water levels used in this study were monitored by 10-min interval from February to May in 2007. Water levels compensated for air pressure were analyzed using a Fast Fourier Transform(FFT) technique for power spectral analysis. Results show periodic variations in 11.38, 12.19, 21.33, 24.38, and 28.44 hours, indicating strong influence of diurnal and semidiurnal tidal components. The diurnal components of the water levels from G1 and G4 in summer had greater power than those in winter, implying that the water table is affected by not only earth tides but evapotranspiration. However, those of the water levels from ft1, ft2 and ft3 do not show seasonal characteristics indicating that evapotranspiration has no influence in water levels of deep monitoring wells.

  14. Water-level fluctuations due to Earth tides in a well pumping from slightly fractured crystalline rock

    International Nuclear Information System (INIS)

    At the Savannah River plant of the Atomic Energy Commission near Aiken, South Carolina, there are three distinct groundwater systems: the coastal plain sediments, the crystalline metamorphic rocks, and a buried Triassic basin. The coastal plain sediments include several Cretaceous and Tertiary granular aquifers and aquicludes, the total thickness being about 305 m. Below these sediments, water occurs in small fractures in crystalline metamorphic rock (hornblende schist and gneiss with lesser amounts of quartzite). Water level fluctuations due to earth tides are recorded in the crystalline metamorphic rock system and in the coastal plain sediments. No water level fluctuations due to earth tides have been observed in wells in the Triassic rock because of the very low permeability. The water level fluctuations due to earth tides in the crystalline rock are about 10 cm, and those in the sediments are about 1.8 cm. The use of water level fluctuations due to earth tides to calculate porosity appears to present practical difficulties both in the crystalline metamorphic rock system and in the coastal plain sediments. In a 1-yr pumping test on a well in the crystalline metamorphic rock the flow was controlled to within 0.1 per cent of the total discharge, which was 0.94 l/s. The water level fluctuations due to earth tides in the pumping well were 10 cm, the same as when this well was not being pumped. (U.S.)

  15. Seismic activity and water level fluctuations in the artificial lakes of Aliakmonas river (NW Greece)

    Science.gov (United States)

    Petrou, Panagiota; Chouliaras, Gerasimos; Drakatos, George

    2015-04-01

    The Public Power Corporation (PPC) of Greece has established four dammed reservoirs, downstream of each other on Aliakmonas River in North Western Greece (namely the artificial lakes of Ilarionas, Polyphyto, Sfikia and Asomata). In addition to the monitoring of the reservoir water levels the PPC has also installed a dense seismological network in the wider area. In this investigation the correlation between the local seismic activity and the water level fluctuations at the Ilarionas and Polyphyto reservoirs is studied. On October 25th, 1984, during the Asomata reservoir initial filling, a Ms=5.4 earthquake occurred in the region which was characterized by weak seismicity, until the strong earthquake of Ms=6.5 that occurred on May 13th, 1995, at a distance of 18 km from the southern edge of the Polyphyto reservoir. More recently, on July 2nd and 3rd, 2013, two moderate earthquakes (Ml=4.7 and Ml=4.6) occurred, almost a year after the filling of the Ilarionas reservoir in 2012. In addition to these events, fourteen earthquakes with magnitudes equal or greater to Ml=4 have also been detected in the wider area of the Aliakmonas reservoir.

  16. Revegetation Strategies for Water-Level Fluctuation Zone of the Three Gorges Reservoir Region

    Directory of Open Access Journals (Sweden)

    JIANG Ming-xi

    2012-05-01

    Full Text Available After the full functioning of the Three Gorges Dam (TGD, the hydrologic regime will be markedly changed and most of the pre-dam vegetation in the new Water-Level Fluctuation Zone (WLFZ may fail to persist. How to revegetate WLFZ of the Three Gorges Reservoir Region (TGRR has become a hot topic for the scientific community and the governments. Based on review of scientific literature and the findings of our research, we here bring forward a scheme addressing strategies for revegetation of WLFZ of TGRR. Firstly, monitor vegetation dynamics based on permanent plots along the Three Gorges upstream from TGD, potentially providing suitable plants for the future revegetation plans. Secondly, examine the potential of soil seed bank for revegetation of the above-ground vegetation, and evaluate self-regeneration of the post-dam vegetation. Based on these data, select suitable plants for revegetation that integrate desirable physiological and life-history traits.Specifically, wetland vegetation could be constructed with lotus (Nelumbo nucifera and aquatic plants. For sites with gentle terrain and fairly hospitable soil conditions, vertical planting of trees, shrubs and grasses / forbs along the elevation gradient could be considered. To attain the sustainable vegetation cover, the newly artificial vegetation should be monitored for at least 5 years.

  17. Effects of fluctuations in river water level on virus removal by bank filtration and aquifer passage--a scenario analysis.

    Science.gov (United States)

    Derx, J; Blaschke, A P; Farnleitner, A H; Pang, L; Blöschl, G; Schijven, J F

    2013-04-01

    Riverbank filtration is an effective process for removing pathogenic viruses from river water. Despite indications that changing hydraulic conditions during floods can affect the efficacy of riverbank filtration to remove viruses, the impact on advection and dispersion of viruses in the riverbank is not well understood. We investigated the effects of fluctuations in river water level on virus transport during riverbank filtration, considering 3-D transient groundwater flow and virus transport. Using constant removal rates from published field experiments with bacteriophages, removal of viruses with distance from the riverbank was simulated for coarse gravel, fine gravel and fine sandy gravel. Our simulations showed that, in comparison with steady flow conditions, fluctuations in river water level cause viruses to be transported further at higher concentrations into the riverbank. A 1-5 m increase in river water levels led to a 2- to 4-log (log10 reduction in concentration relative to the initial concentration in the river) increase in virus concentration and to up to 30% shorter travel times. For particular cases during the receding flood, changing groundwater flow conditions caused that pristine groundwater was carried from further inland and that simulated virus concentrations were more diluted in groundwater. Our study suggests that the adverse effect of water level fluctuations on virus transport should be considered in the simulation of safe setback distances for drinking water supplies. PMID:23500839

  18. Effects of fluctuations in river water level on virus removal by bank filtration and aquifer passage — A scenario analysis

    Science.gov (United States)

    Derx, J.; Blaschke, A. P.; Farnleitner, A. H.; Pang, L.; Blöschl, G.; Schijven, J. F.

    2013-04-01

    Riverbank filtration is an effective process for removing pathogenic viruses from river water. Despite indications that changing hydraulic conditions during floods can affect the efficacy of riverbank filtration to remove viruses, the impact on advection and dispersion of viruses in the riverbank is not well understood. We investigated the effects of fluctuations in river water level on virus transport during riverbank filtration, considering 3-D transient groundwater flow and virus transport. Using constant removal rates from published field experiments with bacteriophages, removal of viruses with distance from the riverbank was simulated for coarse gravel, fine gravel and fine sandy gravel. Our simulations showed that, in comparison with steady flow conditions, fluctuations in river water level cause viruses to be transported further at higher concentrations into the riverbank. A 1-5 m increase in river water levels led to a 2- to 4-log (log10 reduction in concentration relative to the initial concentration in the river) increase in virus concentration and to up to 30 % shorter travel times. For particular cases during the receding flood, changing groundwater flow conditions caused that pristine groundwater was carried from further inland and that simulated virus concentrations were more diluted in groundwater. Our study suggests that the adverse effect of water level fluctuations on virus transport should be considered in the simulation of safe setback distances for drinking water supplies.

  19. Seepage flow-stability analysis of the riverbank of Saigon river due to river water level fluctuation

    CERN Document Server

    Oya, A; Hiraoka, N; Fujimoto, M; Fukagawa, R

    2015-01-01

    The Saigon River, which flows through the center of Ho Chi Minh City, is of critical importance for the development of the city as forms as the main water supply and drainage channel for the city. In recent years, riverbank erosion and failures have become more frequent along the Saigon River, causing flooding and damage to infrastructures near the river. A field investigation and numerical study has been undertaken by our research group to identify factors affecting the riverbank failure. In this paper, field investigation results obtained from multiple investigation points on the Saigon River are presented, followed by a comprehensive coupled finite element analysis of riverbank stability when subjected to river water level fluctuations. The river water level fluctuation has been identified as one of the main factors affecting the riverbank failure, i.e. removal of the balancing hydraulic forces acting on the riverbank during water drawdown.

  20. Can mercury in fish be reduced by water level management? Evaluating the effects of water level fluctuation on mercury accumulation in yellow perch (Perca flavescens)

    Science.gov (United States)

    Larson, James H.; Maki, Ryan P.; Knights, Brent C.; Gray, Brian R.

    2014-01-01

    Mercury (Hg) contamination of fisheries is a major concern for resource managers of many temperate lakes. Anthropogenic Hg contamination is largely derived from atmospheric deposition within a lake’s watershed, but its incorporation into the food web is facilitated by bacterial activity in sediments. Temporal variation in Hg content of fish (young-of-year yellow perch) in the regulated lakes of the Rainy–Namakan complex (on the border of the United States and Canada) has been linked to water level (WL) fluctuations, presumably through variation in sediment inundation. As a result, Hg contamination of fish has been linked to international regulations of WL fluctuation. Here we assess the relationship between WL fluctuations and fish Hg content using a 10-year dataset covering six lakes. Within-year WL rise did not appear in strongly supported models of fish Hg, but year-to-year variation in maximum water levels (?maxWL) was positively associated with fish Hg content. This WL effect varied in magnitude among lakes: In Crane Lake, a 1 m increase in ?maxWL from the previous year was associated with a 108 ng increase in fish Hg content (per gram wet weight), while the same WL change in Kabetogama was associated with only a 5 ng increase in fish Hg content. In half the lakes sampled here, effect sizes could not be distinguished from zero. Given the persistent and wide-ranging extent of Hg contamination and the large number of regulated waterways, future research is needed to identify the conditions in which WL fluctuations influence fish Hg content.

  1. Can mercury in fish be reduced by water level management? Evaluating the effects of water level fluctuation on mercury accumulation in yellow perch (Perca flavescens).

    Science.gov (United States)

    Larson, James H; Maki, Ryan P; Knights, Brent C; Gray, Brian R

    2014-10-01

    Mercury (Hg) contamination of fisheries is a major concern for resource managers of many temperate lakes. Anthropogenic Hg contamination is largely derived from atmospheric deposition within a lake's watershed, but its incorporation into the food web is facilitated by bacterial activity in sediments. Temporal variation in Hg content of fish (young-of-year yellow perch) in the regulated lakes of the Rainy-Namakan complex (on the border of the United States and Canada) has been linked to water level (WL) fluctuations, presumably through variation in sediment inundation. As a result, Hg contamination of fish has been linked to international regulations of WL fluctuation. Here we assess the relationship between WL fluctuations and fish Hg content using a 10-year dataset covering six lakes. Within-year WL rise did not appear in strongly supported models of fish Hg, but year-to-year variation in maximum water levels (?maxWL) was positively associated with fish Hg content. This WL effect varied in magnitude among lakes: In Crane Lake, a 1 m increase in ?maxWL from the previous year was associated with a 108 ng increase in fish Hg content (per gram wet weight), while the same WL change in Kabetogama was associated with only a 5 ng increase in fish Hg content. In half the lakes sampled here, effect sizes could not be distinguished from zero. Given the persistent and wide-ranging extent of Hg contamination and the large number of regulated waterways, future research is needed to identify the conditions in which WL fluctuations influence fish Hg content. PMID:25134675

  2. Deep bore well water level fluctuations in the Koyna region, India: the presence of a low order dynamical system in a seismically active environment

    Directory of Open Access Journals (Sweden)

    D. V. Ramana

    2009-05-01

    Full Text Available Water level fluctuations in deep bore wells in the vicinity of seismically active Koyna region in western India provides an opportunity to understand the causative mechanism underlying reservoir-triggered earthquakes. As the crustal porous rocks behave nonlinearly, their characteristics can be obtained by analysing water level fluctuations, which reflect an integrated response of the medium. A Fractal dimension is one such measure of nonlinear characteristics of porous rock as observed in water level data from the Koyna region. It is inferred in our study that a low nonlinear dynamical system with three variables can predict the water level fluctuations in bore wells.

  3. Predicted Changes in Interannual Water-Level Fluctuations Due to Climate Change and Its Implications for the Vegetation of the Florida Everglades

    Science.gov (United States)

    van der Valk, Arnold G.; Volin, John C.; Wetzel, Paul R.

    2015-04-01

    The number of dominant vegetation types (wet prairies, sawgrass flats, ridges and sloughs, sloughs, and tree islands) historically and currently found in the Everglades, FL, USA, as with other wetlands with standing water, appears to be primarily a function of the magnitude of interannual water-level fluctuations. Analyses of 40 years of water-depth data were used to estimate the magnitude of contemporary (baseline) water-level fluctuations in undisturbed ridge and slough landscapes. Baseline interannual water-level fluctuations above the soil surface were at least 1.5 m. Predicted changes in interannual water-level fluctuations in 2060 were examined for seven climate change scenarios. When rainfall is predicted to increase by 10 %, the wettest scenario, the interannual range of water-level fluctuation increases to 1.8 m above the soil surface in sloughs. When rainfall is predicted to decrease by 10 % and temperatures to increase by 1.5 °C, the driest scenario, the range of interannual range of water-level fluctuations is predicted to decrease to 1.2 m above the soil surface in sloughs. A change of 25-30 cm in interannual water-level fluctuations is needed to change the number of vegetation types in a wetland. This suggests that the two most extreme climate change scenarios could have a significant impact on the overall structure of wetland vegetation, i.e., the number of vegetation types or zones, found in the Everglades.

  4. Water Level Fluctuations in the Congo Basin Derived from ENVISAT Satellite Altimetry

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    Mélanie Becker

    2014-09-01

    Full Text Available In the Congo Basin, the elevated vulnerability of food security and the water supply implies that sustainable development strategies must incorporate the effects of climate change on hydrological regimes. However, the lack of observational hydro-climatic data over the past decades strongly limits the number of studies investigating the effects of climate change in the Congo Basin. We present the largest altimetry-based dataset of water levels ever constituted over the entire Congo Basin. This dataset of water levels illuminates the hydrological regimes of various tributaries of the Congo River. A total of 140 water level time series are extracted using ENVISAT altimetry over the period of 2003 to 2009. To improve the understanding of the physical phenomena dominating the region, we perform a K-means cluster analysis of the altimeter-derived river level height variations to identify groups of hydrologically similar catchments. This analysis reveals nine distinct hydrological regions. The proposed regionalization scheme is validated and therefore considered reliable for estimating monthly water level variations in the Congo Basin. This result confirms the potential of satellite altimetry in monitoring spatio-temporal water level variations as a promising and unprecedented means for improved representation of the hydrologic characteristics in large ungauged river basins.

  5. Seepage Analysis of Rock-Fill Dam Subjected to Water Level Fluctuation: A case study on Gotvand-Olya Dam

    Directory of Open Access Journals (Sweden)

    Ali Beheshti

    2013-01-01

    Full Text Available The Gotvand-Olya Dam is a rock-fill dam, located at Khuzestan province in southwest of Iran. Since the dam is subjected to the daily water level fluctuation, such as rapid drawdown and refill, thus induce a structural impact on the behavior of dam body, it draws many soil engineering concerns. In this paper, seepage analysis of the rock-fill dam was primarily conducted to evaluate the dam safety against the leakage through the dam body. Traditionally, steady-state analysis was employed to investigate the seepage in the dam body, summing that water level is fixed at two cases: high and low water levels. Consequently, it was not able to properly reflect the time-dependent characteristics of seepage phenomena. In this study, seepage analysis was numerically performed using 2-D FEM transient analysis. As a particular boundary condition for an analysis, the water level fluctuation was incorporated to simulate the daily changes. As a result, various seepage phenomena were quantified such as hydraulic gradient, seepage vector and pore water pressure distribution at the corresponding time of interest as the water level rises and recedes. At steady state analysis, the seepage flux at high water level in downstream area was predicted to be 78 l/s. In additions, the seepage flux measured and estimated were both acceptable considering design criteria. The result of this study proves that there is no sign of hazardous sources contributing to the possibility of piping, internal erosion and excess leakage through the dam body.

  6. Dynamics and consequences of water level fluctuations of selected lakes in the catchment of the Ostrowo-Gop?o Channel

    Directory of Open Access Journals (Sweden)

    Piasecki Adam

    2014-12-01

    Full Text Available The article discusses water level fluctuations in lakes and the associated changes in the lake surface and water resources in the years 1992-2011. On the basis of detailed field studies carried out in the hydrological year 2011, short-term and dynamic changes in the lakes’ hydrology were determined. Changes in hydrological lake types were evoked by unexpected hydro-meteorological situations, in particular high precipitation totals and sudden thaws in winter. The main symptom of the lake type change was the restoration, after nearly 10 years, of channels connecting the lakes. In addition, a strong interdependence was recorded in the difference between evaporation and precipitation, as well as the mean annual ranges of lake water levels in the years 1992-2010

  7. Dramatic water-level fluctuations in lakes under intense human impact: modelling the effect of vegetation, climate and hydrogeology

    Science.gov (United States)

    Vainu, M.

    2012-04-01

    Lakes form a highly important ecosystem in the glacial terrain of northern Europe and America, but their hydrology remains understudied. When the water-level of a lake drops significantly and rises again in a time span of half a century and the widespread explanation of the fluctuations seems insufficient, then it raises a question: how do different anthropogenic and natural processes actually affect the formation of a lakes' water body. The abovementioned scenario applies to three small closed-basin Estonian lakes (L. Ahnejärv, L. Kuradijärv and L. Martiska) analysed in the current study. These lakes suffered a major water-level drop (up to 3.8 m) between 1946 and 1987 and a major rise between 1987 and 2010, from 1 m (L. Ahnejärv) to 2.5 m (L. Kuradijärv). Decreasing and increasing groundwater abstraction near the lakes has been widely considered to be the only reason for the fluctuations. It is true that the most severe drop in the lake levels did occur after 1972 when groundwater abstraction for drinking water started in the vicinity of the lakes. However, the lake levels started to fall before the groundwater abstraction began and for the time being the lake levels have risen to a higher level than in the 1970s when the quantity of annually abstracted groundwater was similar to nowadays. Therefore the processes affecting the formation of the lakes' water body prove to be more complex than purely the hydrogeological change caused by groundwater abstraction. A new deterministic water balance model (where the evaporation from the lake surface was calculated by Penman equation and the catchment runoff by Thornthwaite-Mather soil-moisture model), compiled for the study, coupled with LiDAR-based GIS-modelling of the catchments was used to identify the different factors influencing the lakes' water level. The modelling results reveal that the moderate drop in lake water levels before the beginning of groundwater abstraction was probably caused by the growth of a coniferous forest on the lake catchments, due to which evapotranspiration and subsequently runoff from the catchment decreased. The forest had been destroyed by wildfires during World War II. The water-level rise that the lakes have gone through in the last 20 years has in the case of L. Ahnejärv been caused by changing meteorological conditions (precipitation, air temperature and wind speed). In the case of Lakes Kuradijärv and Martiska the change has been caused by both the raise of groundwater level (caused by the decreasing groundwater abstraction) and the change of meteorological conditions. Therefore the vegetation change on the catchment and changes in meteorological conditions have played as important or, at times, even more important role in the water-level fluctuations than changes in the hydrogeological conditions. Although concentrating on three specific lakes in a specific region, the result of the study indicate the complexity of factors influencing the amount of water stored in a lake at a certain moment. Therefore it manifests a need for improved models in order to improve lake management around the world.

  8. Deep bore well water level fluctuations in the Koyna region, India: the presence of a low order dynamical system in a seismically active environment

    OpenAIRE

    Ramana, D. V.; Chelani, A.; Chadha, R. K.; Singh, R. N.

    2009-01-01

    Water level fluctuations in deep bore wells in the vicinity of seismically active Koyna region in western India provides an opportunity to understand the causative mechanism underlying reservoir-triggered earthquakes. As the crustal porous rocks behave nonlinearly, their characteristics can be obtained by analysing water level fluctuations, which reflect an integrated response of the medium. A Fractal dimension is one such measure of nonlinear characteristics of porous rock as observed in wat...

  9. Influence of water level fluctuation on the mortality and aboveground biomass of the aquatic macrophyte Eleocharis interstincta (VAHL) roemer et schults

    OpenAIRE

    Anderson Medeiros dos Santos; Francisco de Assis Esteves

    2004-01-01

    The goal of this study was to study the biometric alterations of Eleocharis interstincta in response to water level fluctuations in Cabiúnas Lagoon, located on the northern coast of the state of Rio de Janeiro, in the municipality of Macaé. Three quadrats of 0.0625 m² were harvested every two weeks from June/1997 to June/1998; samples were separated into stems, dead stems (detritus) and rhizome; lenghted, dried and weighted. The water level fluctuated seasonally in the macrophyte stand wit...

  10. Reasons and Predictions of The Caspian Sea Water Level Fluctuations: Impact of Climate Factors and Man's Activities.

    Science.gov (United States)

    Erlich, M.; Shiklomanov, I.; Yezhov, A.; Georgievsky, V.; Shalygin, A.

    The Caspian Sea - the largest lake in the world - has no connection with the Ocean and is lower than its surface. Fluctuations of the Sea level are very significant: during the period of instrumental observations (since 1830) the level amplitude was 3.78 m with maximum of -25.22 m in 1882 and minimum of -29.00 m in 1978. These fluctuations lead to a great damage for the economy of five countries sharing its coast (Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan). Deep knowledge of hydrological and hydrodynamic Sea regime and scientifically justified forecasts of possible changes in its level, taking into account variability in climate and future climate change, are re- quired for undertaking urgent measures for protection of coastal territories. The inter- national research project CASSEAS, carried out in 1997-2000 within the framework of the INCO-COPERNICUS programme by the scientists of 5 countries: France, Rus- sia, Germany, Turkmenistan and UK, was devoted to these problems. Research made within the Project made it possible to get new precise data on all water balance com- ponents of the Caspian Sea for 1880-1996; moreover, all water balance components for 1940-1996 were computed independently. It was shown that the Sea level fluctua- tions depended on the water balance almost completely. Assessment of possible future runoff changes in the Caspian Sea basin was made using the mathematical model of runoff formation developed at the SHI. Several scenarios from a range of GCMs and on the basis of paleoclimatic reconstructions were used as the models of the future climate for the nearest 3 decades. Besides changes in climate characteristics, three variants were accepted for the future water use in the basins of rivers discharging to the Caspian Sea. All scenarios gave similar results for changes in annual river inflow to the Caspian Sea: its increase would be from 5% to 10% by 2030. The same scenarios, used to estimate changes in precipitation onto the Sea surface and evaporation from it, made it possible to expect visible evaporation increase by 5-10%. To make a prob- abilistic forecast of the Caspian Sea level before 2030 a dynamic stochastic model of the Caspian Sea long-term level fluctuations developed at the SHI was used. The main conclusions based on the modelling results are as follows: - Water level fall is most probable in the future. Mean Sea level mark may be within -27.2 ...-27.3 m (2005), -27.6 ...-28.0 m (2015), -28.4 ...-28.9 m (2030); - A probable Sea level deviation from its mean position at the confidence probability of 95% may be +/- 0.75 m by 2005, +/- 1 1.3 m by 2015 and +/- 1.6 m by 2030; - During the nearest decade the probability of exceedence of the Sea level above -26.0 m would be less than 1%, above -25.5 m less than 0.1% (once per 1000 years); in the next two decades the probability of this event would be even lower; - These conclusions should be considered for decision-making on a development and implementation of projects to protect the coastal zone of the Caspian Sea. 2

  11. Response of Eichhornia crassipes (Pontederiaceae) to water level fluctuations in two lakes with different connectivity in the Paraná River floodplain

    Scientific Electronic Library Online (English)

    Juan José, Neiff; Sylvina Lorena, Casco; Alicia, Poi de Neiff.

    2008-06-01

    Full Text Available Se analiza la respuesta de Eichhornia crassipes, una de las plantas acuáticas más frecuentes en la planicie de inundación del río Paraná, a las fluctuaciones del río en dos lagos con diferente conectividad. Las muestras fueron tomadas en 13 condiciones hidrológicas entre Marzo de 1997 y Diciembre de [...] 2001. Durante el periodo de prolongada conectividad hidrológica, el área cubierta por el agua aumenta más de tres veces y el contenido de nitrógeno inorgánico disuelto fue mayor en comparación con la condición de prolongado aislamiento. En comparación con las plantas del lago más aislado del río, las del más conectado tuvieron significativamente menor densidad de hojas, hojas más largas, menor biomasa de raíces y menor cociente entre la biomasa de las partes aéreas y las partes sumergidas. Las diferencias en la altura y la biomasa de hojas y raíces entre diferentes condiciones hidrológicas y la no significativa relación entre el tamaño y su densidad, indican que las características morfológicas de las plantas responden a fluctuaciones del nivel del agua. Durante la prolongada conexión con el río el contenido de nutrientes de las hojas maduras fue alto, en tanto que durante el aislamiento prolongado las hojas tuvieron mayor contenido de lignina y alto cociente L:N. El éxito de Eichhornia crassipes en la ocupación de hábitats sujetos a amplias y erráticas fluctuaciones del nivel del agua parece estar relacionado con su capacidad para modificar sus características morfológicas en función de las fluctuaciones del nivel del agua. Abstract in english Floodplain lakes are especially dynamic due to the irregular flow regime of the Paraná River and its location along the geomorphologic gradient between the lakes and the river. The response of Eichhornia crassipes (Mart.) Solms (one of the most frequent aquatic plant) was studied in two floodplain l [...] akes with different flooding regimes. Samples were taken between March 1997 and December 2001 on 13 different hydrologic conditions during prolonged hydrologic connection and prolonged hydrologic isolation. Leaf height, leaf density, biomass and nutrient content of the mature leaves of E. crassipes were measured and related to water level fluctuation and the hydrologic connectivity. The lake more connected with the main channel had a long lasting inundation phase. In this condition the surface area covered by water increased more than three times compared to prolonged hydrologic isolation condition. As river water entered the floodplain lakes, dissolved inorganic nitrogen increased to high values, especially NO3-, whereas the isolation condition was characterised by a decrease in NO3- concentrations to undetectable levels. Compared to plants growing in the more isolated lake, those growing in the more connected lake had a significantly lower leaf density, longer leaves, less root biomass and lower ratio between below-ground and above-ground biomasses. However, total and leaf biomasses were not significantly different between sites. In each lake, differences in leaf height, leaf biomass and root biomass between prolonged hydrologic connection and isolation, as well as the insignificant relationship between leaf size and leaf density, indicate that the morphological traits of E. crassipes respond to pluri-annual water level fluctuations. The highest nutrient concentration in mature leaves was registered at the end of the prolonged hydrologic connection in the more connected lake. During the prolonged isolation, leaves had more lignin and a higher L:N ratio than at high waters, at the same sites. The success of E. crassipes in occupying habitats subjected to wide and erratic fluctuations in water level, such as the Paraná River floodplain, appears to be related to its ability to modify morphological traits according to water level. Rev. Biol. Trop. 56 (2): 613-623. Epub 2008 June 30.

  12. Assessing spatial fluctuations, temporal variability, and measurement error in estimated levels of disinfection by-products in tap water: implications for exposure assessment

    OpenAIRE

    Symanski, E.; Savitz, D.; Singer, P.

    2004-01-01

    Aims: To assess spatial fluctuations, temporal variability, and errors due to sampling and analysis in levels of disinfection by-products in routine monitoring tap water samples and in water samples collected in households within the same distribution system for an exposure assessment study.

  13. Revegetation impacts soil nitrogen dynamics in the water level fluctuation zone of the Three Gorges Reservoir, China.

    Science.gov (United States)

    Ye, Chen; Cheng, Xiaoli; Liu, Wenzhi; Zhang, Quanfa

    2015-06-01

    Revegetations in riparian ecosystem are important in regulating soil nitrogen (N) dynamics. However, impacts of revegetation on soil N cycling and thereby on ecosystem functioning are not fully understood. We conducted an in situ incubation in the water level fluctuation zone (WLFZ) of the Three Gorges Reservoir region to evaluate soil N transformation including net N mineralization rate, net ammonification rate, net nitrification rate, net denitrification rate, N leaching and plant N uptake as well as the soil inorganic N (NH4(+)-N and NO3(-)-N) concentration in the top soils (0-20 cm) following revegetations (implementing tree, shrub and herb plantations) over two years. The soil inorganic N concentration and N leaching were lower in the tree soils than in herb and shrub soils. Tree plantations decreased net N mineralization rate and net ammonification rate compared to herb and shrub soils, possibly due to lower soil organic carbon (SOC) input and soil temperatures. Whereas tree plantations increased soil net denitrification rate compared to herb and shrub soils because of higher tree NO3(-)-N uptake together with higher net nitrification rate. The inorganic N in the tree and shrub soils were lower in fall and summer, respectively, which was dependent on the seasonal variations in plant N uptake, soil N transformation, and N leaching. Thus, our results suggest that tree plantations could decrease soil inorganic N concentration and N leaching by altering both the quantity and quality of SOC and thereby potentially improve water quality in the riparian zone. PMID:25723959

  14. Geographic object based image analysis using very high spatial and temporal resolution radar and optical imagery in tracking water level fluctuations in a freshwater reservoir

    OpenAIRE

    Simon, R. N.; Tormos, T.; Danis, P. A.

    2014-01-01

    Tracking water level fluctuations is important to the study and management of waterbodies. A geographic object based image analysis using very high spatial and temporal radar interferometry (Cosmo Skymed and TerraSAR X) and optical (Pléiades) imagery is adopted in this study for this purpose. A linear regression model was sufficient to correlate the water surface area of a mildly sloping and unencumbered littoral zone spatial subset (extracted from 14 images) to water surface altitude data f...

  15. Environmental assessment for the natural fluctuation of water level in Par Pond and reduced water flow in Steel Creek below L-Lake at the Savannah River Site

    International Nuclear Information System (INIS)

    The Savannah River Operations Office Strategic Plan directs Savannah River Site (SRS) to find ways to reduce operating costs, and to determine what site infrastructure must be maintained and what infrastructure is surplus. Because of the mission change, L-Lake, Par Pond, and the river water system are no longer needed to support current missions and therefore provide an opportunity for operating cost reduction. If SRS determines that L-Lake, Par Pond, and the river water system are no longer needed to support future missions and are considered surplus, appropriate NEPA documentation will be prepared. The purpose of the proposed action in this Environmental Assessment is to begin an examination of the need for the Site's river water system by (1) developing data needed to evaluate the potential environmental impacts of further reducing or eliminating the flow demands from the Site's river water system and; (2) evaluating the potential of reducing operating costs by allowing the water level in Par Pond to fluctuate naturally through reduced pumping. This action also includes reducing the current flow rates from L-Lake to Steel Creek to natural stream flows while maintaining full pool. The recently approved Par Pond CERCLA Interim Action Proposed Plan (IAPP) committed to evaluate in a NEPA document the environmental consequences of this proposed action. This document evaluated the remediation of human health and ecological risks associated with the three year drawdown of Par Pond. Should any of the parameters sampled in the reservoir and streams (e.g., water quality, biota, etc.) exceed established threshold levels during the implementation of the proposed action, water would again be pumped into the reservoir to minimize any impacts by bringing the water level back to an appropriate level about 58.2 m (195 ft)

  16. Recovery approach affects soil quality in the water level fluctuation zone of the Three Gorges Reservoir, China: implications for revegetation.

    Science.gov (United States)

    Ye, Chen; Cheng, Xiaoli; Zhang, Quanfa

    2014-02-01

    Plants in the water level fluctuation zone of the Three Gorges Reservoir Region disappeared due to winter-flooding and prolonged inundation. Revegetation (plantation and natural recovery) have been promoted to restore and protect the riparian ecosystem in recent years. Revegetation may affect soil qualities and have broad important implications both for ecological services and soil recovery. In this study, we investigated soil properties including soil pH values, bulk density, soil organic matter (SOM), soil nutrients and heavy metals, soil microbial community structure, microbial biomass, and soil quality index under plantation and natural recovery in the Three Gorges Reservoir Region. Most soil properties showed significant temporal and spatial variations in both the plantation and natural recovery areas. Higher contents of SOM and NO3-N were found in plantation area, while higher contents of soil pH values, bulk density, and total potassium were observed in the natural recovery area. However, there were no significant differences in plant richness and diversity and soil microbial community structure between the two restoration approaches. A soil quality index derived from SOM, bulk density, Zn, Cd, and Hg indicated that natural recovery areas with larger herbaceous coverage had more effective capacity for soil restoration. PMID:24019143

  17. Pattern and Biodiversity of Plant Community in Water-Level-Fluctuation Zone of Pengxi River After 156 m Impoundment of Three Gorges Reservoir

    Directory of Open Access Journals (Sweden)

    WANG Jian-xiu

    2009-10-01

    Full Text Available After impounding to altitude of 156 m, species, spatial pattern and biodiversity of plant community in water-level-fluctuation zone of Three Gorges Reservoir had significant changes. The plant community under altitude of 175 m beside Pengxi River and its tributary Baijia Stream in Kaixian County was studied from July to September, 2008. 108 herb sampling quadrates along five sampling transects, three beside Pengxi River and two beside Baijia Stream, were conducted. The results showed that there are 98 species of vascular plant belong to 38 families, 29 generas. 52 species of wetland plant were investigated. Therophytes(52.0% and cryptophyte (31.6% were the dominant compositions of Raunkiaer’s life. The plant community of study area belonged to 11 associations. Floodplain annual herb zone, Xanthium sibiricum zone, Paspalum paspaloides zone and Imperata cylindrica zone dispersed at the lateral side of Pengxi River and Baijia stream from riparian to altitude of 175 m. The variation and pattern of soil water content significantly influenced the distribution of plant community in water-level-fluctuation zone. There were a low herb biodiversity in water-lever fluctuation zone.

  18. [Mercury dynamics of several plants collected from the water-level fluctuation zone of the Three Gorges Reservoir area during flooding and its impact on water body].

    Science.gov (United States)

    Zhang, Xiang; Zhang, Cheng; Sun, Rong-guo; Wang, Ding-yong

    2014-12-01

    Submerged plants are a major source for the abnormal elevation of methylmercury in reservoir. Several specific plants (Echinochloa crusgalli, Cynodondactylon and Corn stover) were collected and inundated in a simulated aquatic environment in the laboratory for investigating the mercury (Hg) dynamics in plants and the release process into water, aiming to find out the properties of Hg dynamics of plants under inundation conditions and its impact on water body in the Water-Level Fluctuation Zone of the Three Gorges Reservoir Area. The results showed that the contents of total mercury in several plants were in the range of 9. 21-12.07 ng x g(-1), and the percentage content of methylmercury (MeHg) was about 1%-2%. The content of total mercury (THg) in plants gradually decreased, by 35.81%-55.96%, whereas that of the dissolved mercury (DHg) increased sharply, by 103.23% -232.15%, which indicated an emission of Hg from plants to water in the process of decomposition. Furthermore, the state of inundation provided sufficient conditions for the methylation process in plants and therefore caused an increase of the content of methylmercury in the plant residues, which was 3.04-6.63 times as much as the initial content. The concentration of dissolved methylmercury (DMeHg) in the overlying water also increased significantly by 14.84- 16.05 times compared with the initial concentration. Meanwhile, the concentration of dissolved oxygen (DO) in the overlying water was significantly and negatively correlated with DMeHg. On the other hand, the concentration of dissolved organic carbon (DOC) in the overlying water was significantly and positively correlated with DMeHg. During the whole inundation period, the increase of DHg in the overlying water accounted for 41.74% -47.01% of the total amount of THg emission, and there was a negative correlation between the content of THg in plant residues and that of DHg in the overlying water. PMID:25826925

  19. Changes in rotifer communities regarding to the water-level fluctuations in the floodplain Gemenc, Danube (Hungary

    Directory of Open Access Journals (Sweden)

    Schöll, K.

    2006-12-01

    Full Text Available The planktonic rotifer communities in three hydrodynamicaly different river-arms at the floodplain of the Danube River at Gemenc have been studied. In the numerous arms the current has different speeds depending on the water level, therefore the physical and chemical parameters (temperature, conductivity, transparency, dissolved oxygen content are different. We have found forty-six rotifer taxa in the area, but the species-composition changes seasonally. There are therefore big differences in the qualitative and quantitative data between the main arm and the other branches. At high water levels (flood, the rotifer communities of the area are uniformized but, at low water levels the area becomes divided into a series of different water bodies, some near to the lake-state. This phenomenon develops a few days after the flood. The species composition and the abundance relations of the planktonic rotifer communities reflect this effect.

  20. Influence of water level fluctuation on the mortality and aboveground biomass of the aquatic macrophyte Eleocharis interstincta (VAHL roemer et schults

    Directory of Open Access Journals (Sweden)

    Santos Anderson Medeiros dos

    2004-01-01

    Full Text Available The goal of this study was to study the biometric alterations of Eleocharis interstincta in response to water level fluctuations in Cabiúnas Lagoon, located on the northern coast of the state of Rio de Janeiro, in the municipality of Macaé. Three quadrats of 0.0625 m² were harvested every two weeks from June/1997 to June/1998; samples were separated into stems, dead stems (detritus and rhizome; lenghted, dried and weighted. The water level fluctuated seasonally in the macrophyte stand with two periods of drawdown. The first period occurred naturally at the end of winter and beginning of spring, when rainfall in the area was normally lowest. The second period of drawdown was the result of an artificial breaching of the sandbar that isolate the lagoon from the sea. The breach was made in the summer, at the time of highest rainfall, when the water level in the lagoon reached the maximum value recorded during the study (1.35 m. There was a strongly positive correlation of the water level with stems mean height and aboveground biomass, indicating that water level played an important role in the determination of these parameters. There was a significant difference between stem height (ANOVA; p < 0.001 and biomass (ANOVA; p < 0.001 in each sampling period, ranging from 143.9 cm and 338.8 g dry wt.m-2, before the sandbar opening, to 16.3 cm and 20.2 g dry wt.m-2 respectively after the sandbar breaching. The drastic variation of the water level, leading mass mortality of the stems, together with the lowest mean biomass/stem (0.057 g dry wt.individual-1, recorded after the sandbar breaching, did not represent a strong disturbance for E. interstincta, since the resilience time estimated for this population was about 30 days.

  1. Lake level fluctuations boost toxic cyanobacterial ''Oligotrophic Blooms''

    OpenAIRE

    Callieri, Cristiana; Roberto BERTONI; Contesini, Mario; Bertoni, Filippo

    2014-01-01

    Global warming has been shown to strongly influence inland water systems, producing noticeable increases in water temperatures. Rising temperatures, especially when combined with widespread nutrient pollution, directly favour the growth of toxic cyanobacteria. Climate changes have also altered natural water level fluctuations increasing the probability of extreme events as dry periods followed by heavy rains. The massive appearance of Dolichospermum lemmermannii (?=?planktonic Anabaena), ...

  2. Influence of water level fluctuation on the mortality and aboveground biomass of the aquatic macrophyte Eleocharis interstincta (VAHL) roemer et schults

    Scientific Electronic Library Online (English)

    Anderson Medeiros dos, Santos; Francisco de Assis, Esteves.

    2004-06-01

    Full Text Available O objetivo deste trabalho foi verificar as alterações biométricas de Eleocharis interstincta em resposta às variações no nível da água da Lagoa de Cabiúnas, localizada na região norte do Estado do Rio de Janeiro, no município de Macaé (22º00' e 22º30' S, 41º30' e 42º00' O). Três quadrados de 0,0625 [...] m² foram coletados quinzenalmente de junho/1997 a junho/1998; as amostras separadas em caules, detritos e rizoma; medidas, secas e pesadas. O nível da água variou sazonalmente no estande das macrófitas, apresentando dois períodos de seca. O primeiro período ocorreu naturalmente, no final do inverno e início da primavera, quando a precipitação na região é menor. O segundo período de seca foi resultado da abertura artificial da barra de areia, que separa a lagoa do mar. A abertura da barra foi feita no verão, período de maior precipitação, quando o nível da água registrou o máximo valor durante o período de estudo (1,35 m). Foi encontrada uma forte correlação positiva entre o nível da água com o tamanho médio dos caules e a biomassa aérea, indicando que o nível da água desempenha um importante papel na determinação destes parâmetros. Houve uma diferença significativa no tamanho (ANOVA; p Abstract in english The goal of this study was to study the biometric alterations of Eleocharis interstincta in response to water level fluctuations in Cabiúnas Lagoon, located on the northern coast of the state of Rio de Janeiro, in the municipality of Macaé. Three quadrats of 0.0625 m² were harvested every two weeks [...] from June/1997 to June/1998; samples were separated into stems, dead stems (detritus) and rhizome; lenghted, dried and weighted. The water level fluctuated seasonally in the macrophyte stand with two periods of drawdown. The first period occurred naturally at the end of winter and beginning of spring, when rainfall in the area was normally lowest. The second period of drawdown was the result of an artificial breaching of the sandbar that isolate the lagoon from the sea. The breach was made in the summer, at the time of highest rainfall, when the water level in the lagoon reached the maximum value recorded during the study (1.35 m). There was a strongly positive correlation of the water level with stems mean height and aboveground biomass, indicating that water level played an important role in the determination of these parameters. There was a significant difference between stem height (ANOVA; p

  3. Responses of N2O flux to water level fluctuation and other environmental factors at littoral zone of Miyun Reservoir: a comparison with CH4 fluxes

    Science.gov (United States)

    Yang, M.; Geng, X. M.; Grace, J.; Jia, Y. F.; Liu, Y. Z.; Jiao, S. W.; Shi, L. L.; Lu, C.; Zhou, Y.; Lei, G. C.

    2015-04-01

    There have been only a few studies that allow us to estimate the contribution of newly-created reservoirs to greenhouse gas budgets. In particular, information is limited for understanding the spatiotemporal variation of N2O flux and the underlying mechanisms in the littoral zone where complex biochemical processes are induced by water level fluctuations. A study was carried out at five different water levels (deep water area, shallow water area, seasonally flooded area, control site for seasonally flooded area and non-flooded area) at the littoral zone of a temperate reservoir using the static chamber technique. Seasonal and spatial variations of N2O flux and environmental factors were monitored throughout the growing season including a flood event during summer rains. The N2O flux ranged from -2.29 to 182.47 ?g m-2 h-1. Non-flooded dry land emitted more N2O than flooded land, no matter whether it was permanently or seasonally flooded. However, no significant difference was observed between seasonally flooded sites and their control sites. Wind speed, air temperature, soil water content, dissolved oxygen in water and soil nitrate influenced N2O flux significantly. In order to know the contrasting characteristics of N2O and CH4 fluxes in the littoral zone of the reservoir, results were compared with a previous study on CH4 emission carried out at the same sites and time with comparable methods. It showed that N2O flux and CH4 flux was influenced by distinct factors and in differing ways. This work highlights the complexity of N2O flux at the littoral zone. The different response ways of N2O and CH4 to environments implies the big challenge of greenhouse gas emission control through ecosystem management.

  4. Ecological Engineering of Drawdown Wetlands Based on Water-level Fluctuation-Baijia Stream in the Three Gorges Reservoir as a Case Study

    Directory of Open Access Journals (Sweden)

    WANG Qiang

    2012-05-01

    Full Text Available The Three Gorges Reservoir (TGR provides the benefits of flood control, electricity generation and improved transportation along the river corridor. For the purpose of flood control, the reservoir height varies between 145 m and 175 m above sea level, creating a reservoir littoral zone of about 350 km2 in total area distributed along more than 1200 km of shoreline. Most of the littoral zone is flooded during October to May and relatively dry during the remainder of the year. Water level regulation has caused marked ecological changes in the littoral zone of TGR. The littoral zone formed after impounded by TGR not only is the crucible to us, but also the ecological opportunity. The vegetation of large-scale hydro-fluctuation belt is a very valuable resource, if properly used, can turn harm into advantage. In view of the current status and existing problems of the littoral wetland in TGR, we should focus on utilizing resources of the littoral wetland eco-friendly. Based on the needs for the littoral wetland transform into the multifunctional ecological economic benefit such as increasing carbon sources, biological production, and environmental purification, we must develop the ecological engineering model of sustainable utilizing the wetland resources of the littoral zone. In view of the environment problems of TGR and its characteristics of water level fluctuation, the ecological engineering focusing on restoration of littoral wetlands have been carried out since 2008. The eco-logical engineering was mainly conducted at littoral wetlands in Baijia stream of Pengxi River of TGR, including dike-pond system, submergence tolerance wetland-woods and waterfowl habitats recreate projects. The design principle and process for the ecological engineering of littoral wetlands restoration under the condition of the periodic water level change was described in details in this paper. Effects of the ecological engineering and the benefits to the environments were assessed. In the end of the article we proposed that the ecological engineering focus on the restoration of littoral wetlands, also should consider uti.

  5. Global Warming and Caspian Sea Level Fluctuations

    CERN Document Server

    Ardakanian, Reza

    2013-01-01

    Coastal regions have a high social, economical and environmental importance. Due to this importance the sea level fluctuations can have many bad consequences. In this research the correlation between the increasing trend of temperature in coastal stations due to Global Warming and the Caspian Sea level has been established. The Caspian Sea level data has been received from the Jason-1 satellite. It was resulted that the monthly correlation between the temperature and sea level is high and also positive and almost the same for all the stations. But the yearly correlation was negative. It means that the sea level has decreased by the increase in temperature.

  6. Floor level fluctuation in accelerator tunnel

    International Nuclear Information System (INIS)

    Magnet alignment is one of the most important factor for stable particle acceleration. In the KEK-PS main ring, the magnets are aligned in 100 ?m. In 1996 fall, the magnet realignment was done in order to expand the vertical acceptance during the beam injection period. Since the main ring was constructed, a continuous degradation of the floor has been observed for about 20 years. The floor subsidence was mostly brought about by the radiation shields located in the experimental hall. In fact, when the north experimental hall was constructed, the large subsidence of the floor around the beam extraction area was observed. The most origin of the continuous floor subsidence is the heavy materials for the radiation shields, and even now the floor is moving very slowly. The floor subsidence accompanies the corresponding floor upheaval in opposite side of the main ring. As a result, the main ring tunnel inclines and the difference between lowest and highest points has exceeded 2 mm. This floor level fluctuation was considered as rather slow phenomenon in the order of years. In these days, the problem with the floor level fluctuation is closed up since the fast floor movement was observed. The floor level fluctuation damages on the precise magnet alignment and causes the reduction of aperture. It is conjectured that the fast floor fluctuation comes from the moisture in the soil. (author)

  7. Advancing Analysis of Spatio-Temporal Variations of Soil Nutrients in the Water Level Fluctuation Zone of China’s Three Gorges Reservoir Using Self-Organizing Map

    Science.gov (United States)

    Ye, Chen; Li, Siyue; Yang, Yuyi; Shu, Xiao; Zhang, Jiaquan; Zhang, Quanfa

    2015-01-01

    The ~350 km2 water level fluctuation zone (WLFZ) in the Three Gorges Reservoir (TGR) of China, situated at the intersection of terrestrial and aquatic ecosystems, experiences a great hydrological change with prolonged winter inundation. Soil samples were collected in 12 sites pre- (September 2008) and post submergence (June 2009) in the WLFZ and analyzed for soil nutrients. Self-organizing map (SOM) and statistical analysis including multi-way ANOVA, paired-T test, and stepwise least squares multiple regression were employed to determine the spatio-temporal variations of soil nutrients in relation to submergence, and their correlations with soil physical characteristics. Results showed significant spatial variability in nutrients along ~600 km long shoreline of the TGR before and after submergence. There were higher contents of organic matter, total nitrogen (TN), and nitrate (NO3-) in the lower reach and total phosphorus (TP) in the upper reach that were primarily due to the spatial variations in soil particle size composition and anthropogenic activities. Submergence enhanced soil available potassium (K), while significantly decreased soil N, possibly due to the alterations of soil particle size composition and increase in soil pH. In addition, SOM analysis determined important roles of soil pH value, bulk density, soil particle size (i.e., silt and sand) and nutrients (TP, TK, and AK) on the spatial and temporal variations in soil quality. Our results suggest that urban sewage and agricultural runoffs are primary pollutants that affect soil nutrients in the WLFZ of TGR. PMID:25789612

  8. Spatial patterns of zooplanktivore Chirostoma species (Atherinopsidae) during water-level fluctuation in the shallow tropical Lake Chapala, Mexico: seasonal and interannual analysis

    Scientific Electronic Library Online (English)

    Rodrigo, Moncayo-Estrada; Carlos, Escalera-Gallardo; Owen T., Lind.

    Full Text Available El presente estudio describe la influencia que tiene la fluctuación del nivel del agua en la distribución de los peces a dos diferentes escalas: estacional (estiaje y lluvias) e interanual (condiciones de bajo y alto volumen). El análisis de las relaciones de abundancia entre tres especies zooplanct [...] ófagas de Chirostoma en quince sitios del Lago de Chapala, México, reveló una influencia estadísticamente significativa en las condiciones contrastantes (P=0.0002). Estacionalmente, la segregación estuvo más relacionada a la dominancia de las especies en la época de estiaje y exclusivamente relacionada a las características ambientales en la época de lluvias. Interanualmente, la influencia biótica se presenta en los episodios más someros y más profundos del lago. Las características ambientales influenciaron la distribución de las especies cuando el lago alcanzó el 25% de su volumen. El sitio geográfico, profundidad, temperatura y salinidad fueron los principales factores que influenciaron la distribución de los peces. Estos resultados enfatizan la necesidad de implementar diferentes estrategias de manejo de acuerdo al volumen del lago, particularmente cuando se alcanza un umbral crítico. Abstract in english This study addresses the influence of water-level fluctuations on fish distribution at two temporal scales: seasonal (dry and rainy) and interannual (low and high volume conditions). The analysis of abundance relationships among three zooplanktivore Chirostoma species at fifteen sites in Lake Chapal [...] a, Mexico, revealed the significant influence of contrasting conditions (P=0.0002). Seasonally, segregation was more related to species dominance in the dry season and exclusively related to environmental characteristics in the rainy season. Interanually, biotic influence occurred in the shallowest and the deepest episodes of the lake. Environmental characteristics influenced species distribution when the lake reached 25% of its volume. Site, depth, temperature, and salinity were the leading factors influencing fish distribution. These results emphasize the necessity to implement different management strategies according to lake volume, particularly when a critical threshold is reached.

  9. River and cooling water temperature fluctuations

    International Nuclear Information System (INIS)

    Cooling water discharged from a power plant changes the fluctuating water temperature characteristics of a receiving river in a clearly detectable way. Daily and hourly water temperature data from two power plant sites on the Upper Mississippi River were used to compute for illustration the magnitude of such differences. Extreme value analysis, autocovariance and spectral analysis, and nonlinear curve fitting methods were applied alternatively. Amplitudes of seasonal periodicities, of diurnal periodicities, and of random components were determined. The results indicate that time series analysis of water temperatures measured downstream from an existing cooling water outfall may provide equally or even more realistic and useful information on the size of a cooling water plume than quasi-instantaneous surveys of spatial water temperature distributions

  10. Fluctuation of Groundwater Levels and Recharge Patterns in Northern Ghana

    Directory of Open Access Journals (Sweden)

    Alexandra Lutz

    2014-12-01

    Full Text Available Evaluating groundwater levels and recharge patterns is part of sustainably managing the water supply and predicting the possibility of water shortages, especially in light of climate change, extreme events (floods/droughts, increasing population and development. In the northern region of Ghana, groundwater is increasingly relied upon as a source of potable water for rural populations, but seasonal and inter-annual fluctuations of groundwater levels and recharge patterns are not always known. The fluctuation of groundwater levels on a seasonal basis shows that groundwater levels at all sites increase in response to seasonal precipitation. On an annual basis, all sites show an overall net decline of groundwater levels over the study period, which may be associated with below-average departures of precipitation during five of the seven study years. The variability of recharge patterns among five sites is attributed to the spatio-temporal variability of precipitation and hydrogeologic site uniqueness. The overarching potential benefit of this study is to facilitate closing knowledge gaps and contribute to a foundation for a more robust evaluation of groundwater resources in the area, especially as more data become available.

  11. Mesoscale wind fluctuations over Danish waters

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, C.L.

    2010-12-15

    Mesoscale wind fluctuations affect the large scale integration of wind power because they undermine the day-ahead predictability of wind speed and power production, and because they can result in large fluctuations in power generation that must be balanced using reserve power. Large fluctuations in generated power are a particular problem for offshore wind farms because the typically high concentration of turbines within a limited geographical area means that fluctuations can be correlated across large numbers of turbines. Furthermore, organised mesoscale structures that often form over water, such as convective rolls and cellular convection, have length scales of tens of kilometers, and can cause large wind fluctuations on a time scale of around an hour. This thesis is an exploration of the predictability of mesoscale wind fluctuations using observations from the world's first two large offshore wind farms - Horns Rev I in the North Sea, and Nysted in the Baltic Sea. The thesis begins with a climatological analysis of wind fluctuations on time scales of 1-10 hours at the two sites. A novel method for calculating conditional climatologies of spectral information is proposed, based on binning and averaging the time axis of the Hilbert spectrum. Results reveal clear patterns between wind fluctuations and locally observed meteorological conditions. The analysis is expanded by classifying wind fluctuations on time scales of 1-3 hours according to synoptic patterns, satellite pictures and wind classes. Results indicate that cold air outbreaks and open cellular convection are a significant contributor to mesoscale wind variability at Horns Rev. The predictability of mesoscale wind fluctuations is tested by implementing standard statistical models that relate local wind variability to parameters based on a large scale weather analysis. The models show some skill, but only achieve a 15% improvement on a persistence forecast. The possibility of explicitly modelling mesoscale fluctuations in a mesoscale model is then examined using the weather research and forecasting (WRF) model. A set of case studies demonstrate that realistic hour-scale wind fluctuations and open cellular convection patterns develop in WRF simulations with 2 km horizontal grid spacing. The atmospheric conditions during one of the case studies are then used to initialise a simplified version of the model that has no large scale weather forcing, topography or surface inhomogeneties. Using the simplified model, the sensitivity of the modelled open cellular convection to choices in model setup and to aspects of the environmental forcing are tested. Finally, the cell-scale kinetic energy budget of the modelled cells is calculated, and it is shown that the buoyancy and pressure balance terms are important for cell maintenance. It is explained that the representation of mesoscale convection in a mesoscale model is not only important to end users such as wind farm operators, but to the treatment of energy transport within the boundary layer. (Author)

  12. Impact of water table fluctuations on water flow and solute transport in 1D column systems

    Science.gov (United States)

    Rühle, F.; Stumpp, C.

    2012-04-01

    Although hydrological processes and mass fluxes in the unsaturated and saturated zone have been well studied separately, little is known about transition processes between these zones. Since the transition zone is dynamic and varies spatially and temporally with fluctuations of the water table, water flow and solute transport are believed to vary dynamically, too. This may influence the transport and fate of dissolved contaminants and consequently the quality of groundwater. In order to protect and maintain drinking water resources, improved understanding about hydrological processes at the dynamic interface between the unsaturated and saturated zone is needed. The objective of this study was to investigate the impact of water table fluctuations on one-dimensional vertical flow and solute transport in laboratory column systems. Therefore, two flow-through columns were constantly irrigated with groundwater at an infiltration rate of 4.7 cm/d. In one column the water table was kept statically fixed in the middle, in the other column the water table was continually fluctuated by regularly raising and lowering the outflow tube. Several multi-tracer experiments were conducted and compared injecting the tracers bromide, deuterium and 18-oxygen at different water levels. Data modelling was performed with a lumped parameter model to simulate the hydrological fluxes. Our results showed that at static water table and similar water fluxes in both columns, structural heterogeneities due to packing lead to differences in solute transport, e.g. different dispersivity. Tracer breakthrough curves were well simulated with the lumped parameter model indicating that the systems were at steady state. When the water table was fluctuated small differences in solute transport were observed. Even with a fluctuating water table the lumped parameter model yielded high modelling accuracy and indicated that under certain hydrological conditions water table fluctuations lead to slightly increased dispersivity. It is suggested that the increased dispersivities are caused by a falling water table, which was faster declining compared to the water flux resulting in a more extensive solute distribution over depth. For a more precise identification of hydrological processes and mechanisms occurring near fluctuating water tables a model is needed that accounts for physical non-equilibrium of the system. In conclusion, water table fluctuations contribute to spreading of solutes and have to be considered in predicting the behaviour of dissolved contaminants in soils.

  13. Determining the mean hydraulic gradient of ground water affected by tidal fluctuations

    Science.gov (United States)

    Serfes, Michael E.

    1991-01-01

    Tidal fluctuations in surface-water bodies produce progressive pressure waves in adjacent aquifers. As these pressure waves propagate inland, ground-water levels and hydraulic gradients continuously fluctuate, creating a situation where a single set of water-level measurements cannot be used to accurately characterize ground-water flow. For example, a time series of water levels measured in a confined aquifer in Atlantic City, New Jersey, showed that the hydraulic gradient ranged from .01 to .001 with a 22-degree change in direction during a tidal day of approximately 25 hours. At any point where ground water tidally fluctuates, the magnitude and direction of the hydraulic gradient fluctuates about the mean or regional hydraulic gradient. The net effect of these fluctuations on ground-water flow can be determined using the mean hydraulic gradient, which can be calculated by comparing mean ground- and surface-water elevations. Filtering methods traditionally used to determine daily mean sea level can be similarly applied to ground water to determine mean levels. Method (1) uses 71 consecutive hourly water-level observations to accurately determine the mean level. Method (2) approximates the mean level using only 25 consecutive hourly observations; however, there is a small error associated with this method.

  14. Spatial-temporal Dynamics of Vegetation in the Newly Created Water-level-fluctuation Zone of Three Gorges Reservoir:a Case Study in Baijia Stream, Kaixian County, China

    Directory of Open Access Journals (Sweden)

    YUAN Xing-zhong

    2012-05-01

    Full Text Available "After impoundent of the Three Gorges Reservoir, a large permanent sample plot was placed in its water-level-fluctuation zone beside Baijia Stream, Kaixian County, China. Vegetation in the plot was investigated in the summer of 2008,2009 and 2010. The result indicated that community' s component, biodiversity and aboveground biomass showed obvious spatial-temporal dynamics. Total spiecies number of vascular flora inside decreased yearly, from 52 species in 2008 to 41 species in 2009 and to 35 species in 2010. The area below 156 m in elevation was dominated by Paspalum paspaloides andXanthium sibiricum in 2008. However, Paspalum paspaloides was rapid replaced by Cynodon dactylo in 2009 and X. sibiricum expanded its distribution in upper area of the plot. In 2010, X. sibiricum depressed its population in lower areas of the plot as the Three Gorges Reservoir started to impound half month earlier in the winter of 2009 and decreased seed bank for its germination. Shannon-Wiener Index increased as elevation according to the data of 2009 and 2010, which reflected the influ-ence of submerged gradient. Aboveground biomass of vegetation in each elevation zone of the plot indicated great variation.Key words: Three Gorges Reservoir; water-level-fluctuation zone; vegetation; spatial-temporal dynamics; biodiversity"

  15. Water Level Station History

    National Oceanic and Atmospheric Administration, Department of Commerce — Images contain station history information for 175 stations in the National Water Level Observation Network (NWLON). The NWLON is a network of long-term,...

  16. Air encapsulation. II. Profile water storage and shallow water table fluctuations

    International Nuclear Information System (INIS)

    In a wet soil, volumetric encapsulated air contents can easily approach 0.06 m3 m-3. The objective of this study was to determine, through simulation, the effect of air encapsulation on profile water storage and shallow water table fluctuations and whether air encapsulation should be considered in modeling field events. Using a two-dimensional soil moisture code that included a routine designed to model air encapsulation, the authors simulated profile water storage changes during hypothetical rainfall events and water table responses during actual rainfall events. The simulation results indicated that, following the infiltration of 10 mm of water, profile moisture content differences with and without air encapsulation would be 3 m-3 and thus may not be measurable in the field with a neutron probe. Water table levels, however, rose significantly higher in the profile when air was encapsulated. Depending on the initial depth of the water table and the moisture characteristic, the water table rises were two to five times those when air was not encapsulated. For water tables located within 1.3 m of the surface, application of the model to actual rainfall events improved the fit to the measured water table data. In those situations where water table level predictions are important (e.g., wetlands, stream banks), researchers should consider air encapsulation in their analysis of water table fluctuations

  17. Hydrophobic nanoconfinement suppresses fluctuations in supercooled water

    International Nuclear Information System (INIS)

    We perform very efficient Monte Carlo simulations to study the phase diagram of a water monolayer confined in a fixed disordered matrix of hydrophobic nanoparticles between two hydrophobic plates. We consider different hydrophobic nanoparticle concentrations c. We adopt a coarse-grained model of water that, for c = 0, displays a first-order liquid-liquid phase transition (LLPT) line with negative slope in the pressure-temperature (P-T) plane, ending in a liquid-liquid critical point at about 174 K and 0.13 GPa. We show that upon increase of c the liquid-gas spinodal and the temperature of the maximum density line are shifted with respect to the c = 0 case. We also find dramatic changes in the region around the LLPT. In particular, we observe a substantial (more than 90%) decrease of isothermal compressibility, thermal expansion coefficient and constant-pressure specific heat upon increasing c, consistent with recent experiments. Moreover, we find that a hydrophobic nanoparticle concentration as small as c = 2.4% is enough to destroy the LLPT for P ? 0.16 GPa. The fluctuations of volume apparently diverge at P ? 0.16 GPa, suggesting that the LLPT line ends in an LL critical point at 0.16 GPa. Therefore, nanoconfinement reduces the range of P-T where the LLPT is observable. By increasing the hydrophobic nanoparticle concentration c, the LLPT becomes weaker and its P-T range smaller. The model allows us to explain these phenomena in terms of a proliferation of interf in terms of a proliferation of interfaces among domains with different local order, promoted by the hydrophobic effect of the water-hydrophobic-nanoparticle interfaces. (paper)

  18. [Ultraviolet-visible (UV-Vis) and fluorescence spectral characteristics of dissolved organic matter (DOM) in soils of water-level fluctuation zones of the Three Gorges Reservoir Region].

    Science.gov (United States)

    Gao, Jie; Jiang Tao; Li, Lu-lu; Chen, Xue-shuang; Wei, Shi-qiang; Wang, Ding-yong; Yan, Jin- long; Zhao, Zheng

    2015-01-01

    Ultraviolet-visible (UV-Vis) absorption spectroscopy and three-dimensional fluorescence spectroscopy, combined with fluorescence regional integration were conducted to investigate the geochemical characteristics of DOM extracted from soils of water-level fluctuation zones of the Three Gorges Reservoir Region. The results showed that the average CDOM concentrations in soils were in order of Zhongxian > Fengdu > Fuling > Wanzhou > Wushan > Yunyang > Fengjie > Kaixian. Additionally, in Zhongxian, Fengdu and Fuling, the CDOM concentration [a (355)], aromaticity (SUVA254) and hydrophobicity (SUVA260) were all much higher than those at the other sampling sites, but the humification index (HIX) was lower. Four fluorophores were observed in all soil DOM samples, including three humic-like fluorescence peaks (A, C and M respectively) and one tryptophan-like fluorescence peak (T). Proportion of fluorescence regional integration of ultraviolet region humic-like A fluorophore was the highest as compared with the others. More importantly, tryptophan-like fluorophore (T) and a(355) showed significant correlation (r = 0.674, P < 0.01), indicating the variance of CDOM concentration was possibly dependent on T fluorophore. Meanwhile, the total integrated fluorescence intensity(TOT) of 3D- EEM was an appropriate parameter to characterize the total contributions of fluorophores in DOM. Furthermore, the humification degree of DOM in soils was low in comparison with higher biological availability. Conclusively it seemed that the influence of "alternation of wetting and drying" resulted from water-level fluctuation on the geochemical characteristics of soil DOM was not significant as expected. It might be related to local agricultural activity, littoral plant growth and DOM mineralization process. PMID:25898659

  19. Sea Levels Online: Sea Level Variations of the United States Derived from National Water Level Observation Network Stations

    National Oceanic and Atmospheric Administration, Department of Commerce — Water level records are a combination of the fluctuations of the ocean and the vertical land motion at the location of the station. Monthly mean sea level (MSL)...

  20. Dietary factors and fluctuating levels of melatonin

    Directory of Open Access Journals (Sweden)

    Katri Peuhkuri

    2012-07-01

    Full Text Available Melatonin is secreted principally by the pineal gland and mainly at nighttime. The primary physiological function is to convey information of the daily cycle of light and darkness to the body. In addition, it may have other health-related functions. Melatonin is synthesized from tryptophan, an essential dietary amino acid. It has been demonstrated that some nutritional factors, such as intake of vegetables, caffeine, and some vitamins and minerals, could modify melatonin production but with less intensity than light, the most dominant synchronizer of melatonin production. This review will focus on the nutritional factors apart from the intake of tryptophan that affect melatonin levels in humans. Overall, foods containing melatonin or promoting the synthesis of it by impacting the availability of tryptophan, as well those containing vitamins and minerals which are needed as co-factors and activators in the synthesis of melatonin, may modulate the levels of melatonin. Even so, the influence of daytime diet on the synthesis of nocturnal melatonin is limited, however, the influence of the diet seems to be more obvious on the daytime levels.

  1. Water level indicator

    International Nuclear Information System (INIS)

    A difference of pressure between a standard pressure conduit in communication with a gas phase of a reactor pressure vessel and a water level pressure conduit in communication with a liquid phase of the pressure vessel is detected by a pressure difference gage. A communication pipe and a standard level vessel are disposed between the pressure vessel and the standard pressure conduit, and a standard liquid surface on the side of the standard pressure conduit is formed in the standard level vessel. A gas releaser is disposed to the gas phase portion of the standard level vessel. The gas releaser equipment is constituted by a porous material, a permeation membrane and a gas exhaustion hole. The gas phase of the standard level vessel is divided by a partition plate into a first gas phase being in contact with a connection portion with the communication pipe and a second gas phase in contact with the gas releaser. A gas flow channel hole and a condensate descending hole are disposed to the partition plate. Since incondensible gases accumulated to the standard level vessel are effectively exhausted, the incondensible gases are prevented from being dissolved into liquid. (I.N.)

  2. Experimental and Modeling Investigation of Shallow Water Table Fluctuations in Relation to Reverse Wieringermeer Effect

    OpenAIRE

    Ibrahimi Mohamed Khaled; Miyazaki Tsuyoshi; Nishikawa Kohei; Nishimura Taku; Imoto Hiromi

    2011-01-01

    Soil column experiments and modeling investigations were performed to study the behavior of shallow water table in response to various recharge events. Hence, shallow water table fluctuations inside sandy (Toyoura sand) and clayey (Chiba light clay) soil columns in response to surface and sub-surface recharge events were investigated under laboratory conditions. Experimental results showed that small application of water could raise the shallow water table level more than 100 times in depth i...

  3. Diurnal Water Table Fluctuations: An Underutilized Indicator of Ground-water Consumption by Plants

    Science.gov (United States)

    Bauer, J. P.; Shea, J.; Keller, J.; Butler, J. J.; Kluitenberg, G.; Whittemore, D. O.

    2005-12-01

    Hydrographs from shallow wells in areas with phreatophytes frequently display a distinctive pattern of diurnal fluctuations. Although first linked to variations in plant water use early in the last century, these diurnal fluctuations have received relatively little attention in the ecohydrology literature. In particular, little attention has been given to exploiting the information embedded in the water-level data to improve understanding of plant water use. Results from two field sites in western Kansas will be presented to demonstrate the insights that can be gleaned from these fluctuations. At one site the vegetation is representative of the native riparian-zone assemblage found over much of the Great Plains (major phreatophyte is the cottonwood [ Populus spp.]), whereas at the other site the vegetation is dominated by invasive species (salt cedar [ Tamarix spp.] and Russian olive [ Elaeagnus angustifoli]). Both sites have a network of shallow wells and neutron probe access tubes for monitoring water-table position and moisture content, respectively. The onset and termination of ground-water use by plants during the growing season is readily identifiable at both sites. Data from the first site show that the maximum depth from which phreatophytes can draw water depends on the previous hydrologic conditions experienced at the site, and not the physiological limits of the plant. Phreatophyte control actions (mulch cutting and chemical treatment) have recently been applied in a sequential fashion to a portion of the second site. The initial impact of those actions on ground-water consumption was not as large as expected, suggesting that forbs and grasses, which were not significantly impacted by these actions, also use substantial amounts of ground water. The magnitude of the diurnal fluctuations ranges appreciably between the sites, and even between wells at the same site. A portion of this difference can be attributed to variations in plant water uptake across a site. Often, however, a more important factor is variation in the specific yield of the sediments in the vicinity of the water table. Thus, the hydrogeology of the shallow subsurface cannot be ignored in interpretations of the fluctuations.

  4. Flux Lattice Melting and Lowest Landau Level Fluctuations

    OpenAIRE

    Pierson, Stephen W; Valls, Oriol T

    1997-01-01

    We discuss the influence of lowest Landau level (LLL) fluctuations near H_{c2}(T) on flux lattice melting in YBa$_2$Cu$_3$O$_{7-\\delta}$ (YBCO). We show that the specific heat step of the flux lattice melting transition in YBCO single crystals can be attributed largely to the degrees of freedom associated with LLL fluctuations. These degrees of freedom have already been shown to account for most of the latent heat. We also show that these results are a consequence of the cor...

  5. Barotropic current fluctuations coupled with sea level drawdown in Yellow and Bohai Seas

    Science.gov (United States)

    Wan, Kai; Bao, Xianwen; Wang, Yi; Wan, Xiuquan; Li, Haoqian; Liu, Ke

    2015-01-01

    Sub-tidal barotropic current variations coupled with residual sea level fluctuation in the Bohai and Yellow Seas during wintertime are addressed in this study. The temporal evolution and spatial distribution of current fluctuation are investigated using moored acoustic Doppler current profiler data in a three-dimensional numerical model. It is found that a southward current followed by a northward current occurred in the northern Yellow Sea during the fluctuation, concurrent with a significant outflow followed by inflow through the Bohai Strait. The process is consistent from surface to bottom and is coupled with remarkable residual sea level fluctuation. This quasi three-day fluctuation with amplitude 0.2-0.3 m/s leads to 1 m/1.2 m drawdown in the northern Yellow and Bohai Seas, respectively, strongly influencing water exchange between those seas. Because this a prominent feature in the seas, it is necessary to evaluate its effect on fluctuation during winter in future studies, in particular, the northward current during the recovery phase of sea level in the Bohai and Yellow Seas regarding seasonal variation.

  6. How the fluctuations of water levels affect populations of invasive bivalve Corbicula fluminea (Müller, 1774) in a Neotropical reservoir? / Como a flutuação dos níveis da água afetam as populações do bivalve invasor Corbicula fluminea (Müller, 1774) em um reservatório neotropical?

    Scientific Electronic Library Online (English)

    LRP., Paschoal; DP., Andrade; G., Darrigran.

    2015-03-01

    Full Text Available Corbicula fluminea é um bivalve invasor, responsável por inúmeros problemas ambientais e econômicos ao redor do mundo. Apesar de sua capacidade de invasão, a espécie sofre certas restrições devido a fenômenos naturais em ambientes lênticos, afetando significativamente sua estrutura populacional (e.g [...] . flutuação do nível da água e a exposição à luz solar). O presente trabalho avaliou como o decréscimo temporal do nível da água de um reservatório neotropical e a exposição solar, afeta a estrutura populacional de C. fluminea. Duas amostragens foram realizadas no reservatório da Usina Hidrelétrica (UHE) de Furnas (Minas Gerais, Brasil), em 2011 e 2012. A densidade populacional, o comprimento médio e a distribuição espacial da espécie para cada ano foram estimados após amostragem em 51 quadrats (0,0625m2) dispostos em três transectos em diferentes distâncias das margens do reservatório (0, 10 e 20 m em relação a um ponto fixo). Observou-se o predomínio de C. fluminea em ambos os anos, coincidindo com o decréscimo da densidade e riqueza de espécies nativas nas áreas de amostragem. Foram registradas diferenças significativas na densidade de C. fluminea entre as distâncias da margem, sendo atribuídas principalmente à variabilidade temporal do substrato e da água desses ambientes. Registrou-se também uma tendência em aumento da densidade e agregação com o aumento da distância da margem, devido à maior estabilidade dessas áreas (>10 m). Houveram diferenças significativas no tamanho médio das conchas de C. fluminea entre às distâncias da margem e durante os anos, assim como na interação desses fatores (Distâncias vs. Anos). Tais resultados foram associados à capacidade reprodutiva e invasiva da espécie. Esse estudo revelou que eventos temporais (principalmente, a flutuação do nível da água) em ambientes lênticos neotropicais provocam alterações na densidade, tamanho médio e distribuição de C. fluminea e na composição da malacofauna nativa. Abstract in english Corbicula fluminea is an invasive bivalve responsible for several environmental and financial problems around the globe. Despite the invasive potential of this species, it suffers certain restrictions in lentic environments due to natural phenomena that significantly affect its population structure [...] (e.g. water column fluctuation and sunlight exposure). The present study addresses how temporal decline of the water level in a Neotropical reservoir and exposure to sunlight affect the population structure of C. fluminea. Samplings were carried out twice in the reservoir of Furnas Hydroelectric Power Station (HPS) (Minas Gerais, Brazil), in 2011 and 2012. Population density, spatial distribution and mean shell length of C. fluminea were estimated for each year after sampling in 51 quadrats (0.0625m2) placed on three transects at different distances along the reservoir margins (0, 10 and 20 m from a fixed-point). We observed a predominance of C. fluminea in both years, with a simultaneous gradual decrease in density and richness of native species in the sampling area. Significant differences in density of C. fluminea were registered at different distances from the margin, and are related to the temporal variability of physical conditions of the sediment and water in these environments. We also registered a trend toward an increase in the density and aggregation of C. fluminea as we moved away from the margin, due to the greater stability of these areas (>10 m). The mean shell length of C. fluminea showed significant difference between the distinct distances from the margin and during the years, as well as the interaction of these factors (Distances vs.Years). These results were associated with the reproductive and invasive capacity of this species. This study reveals that these temporal events (especially water column fluctuation) may cause alterations in density, spatial distribution and mean shell length of C. fluminea and the composition of the native malacofauna in Neotropical

  7. Chronology of fluctuating sea levels since the triassic.

    Science.gov (United States)

    Haq, B U; Hardenbol, J; Vail, P R

    1987-03-01

    Advances in sequence stratigraphy and the development of depositional models have helped explain the origin of genetically related sedimentary packages during sea level cycles. These concepts have provided the basis for the recognition of sea level events in subsurface data and in outcrops of marine sediments around the world. Knowledge of these events has led to a new generation of Mesozoic and Cenozoic global cycle charts that chronicle the history of sea level fluctuations during the past 250 million years in greater detail than was possible from seismic-stratigraphic data alone. An effort has been made to develop a realistic and accurate time scale and widely applicable chronostratigraphy and to integrate depositional sequences documented in public domain outcrop sections from various basins with this chronostratigraphic framework. A description of this approach and an account of the results, illustrated by sea level cycle charts of the Cenozoic, Cretaceous, Jurassic, and Triassic intervals, are presented. PMID:17818978

  8. High frequency sea level fluctuations recorded in the Black Sea since the LGM

    OpenAIRE

    Lericolais, Gilles; Bulois, C.; Gillet, Herve; Guichard, F.

    2009-01-01

    This paper presents a 3D geometric interpretation of very high resolution seismic Chirp profiles acquired on the Romanian shelf during ASSEMBLAGE European Project. The results provide a solid record of the Black Sea Last Glacial Maximum (LGM) water level fluctuations. This pseudo-3D seismic interpretation shows that the Black Sea lacustrine shelf deposits form a significant basinward-prograding wedge system. on top of these prograding sequences is a set of sand dunes that delineates a wave cu...

  9. Reactor water level measuring device

    International Nuclear Information System (INIS)

    The device of the present invention contributes to an improvement of maintenance and economics by decreasing the number and the kinds of water level transmitters disposed in a plant site. That is, a plurality of reactor water level monitors disposed in the plant site and a reactor water level monitor disposed in a central operation chamber are connected by a light transmission line. A plant operation state is judged by the monitor in the central operation chamber, and appropriate measuring range switching signals are sent to the water level detectors in the plant site depending on the conditions. Further, water level signals sent from the water level detectors are received in the central operation chamber and a circuit corresponding to the measuring range switching signals is selected, and the reactor water level is displayed by a recorder. Further, if requirement for the measuring range and calibration data of the water level detectors is sent to the water level detectors in the plant site by a selection switch of the monitor in the central operation chamber, the range is recognized and the calibration data are checked, and the results are inputted to a recording circuit of the monitor. (I.S.)

  10. Mesoscale wind fluctuations over Danish waters

    DEFF Research Database (Denmark)

    Vincent, Claire Louise

    2010-01-01

    Mesoscale wind uctuations aect the large scale integration of wind power because they undermine the day-ahead predictability of wind speed and power production, and because they can result in large uctuations in power generation that must be balanced using reserve power. Large uctuations in generated power are a particular problem for oshore wind farms because the typically high concentration of turbines within a limited geographical area means that uctuations can be correlated across large numbers of turbines. Furthermore, organised mesoscale structures that often form over water, such as convective rolls and cellular convection, have length scales of tens of kilometers, and can cause large wind uctuations on a time scale of around an hour. This thesis is an exploration of the predictability of mesoscale wind uctuations using observations from the world's rst two large oshore wind farms - Horns Rev I in the North Sea, and Nysted in the Baltic Sea. The thesis begins with a climatological analysis of wind uctuations on time scales of 1{10 hours at the two sites. A novel method for calculating conditional climatologies of spectral information is proposed, based on binning and averaging the time axis of the Hilbert spectrum. Results reveal clear patterns between wind uctuations and locally observed meteorological conditions. The analysis is expanded by classifying wind uctuations on time scales of 1{3 hours according to synoptic patterns, satellite pictures and wind classes. Results indicate that cold air outbreaks and open cellular convection are a signicant contributor to mesoscale wind variability at Horns Rev. The predictability of mesoscale wind uctuations is tested by implementing standard statistical models that relate local wind variability to parameters based on a large scale weather analysis. The models show some skill, but only achieve a 15% improvement on a persistence forecast. The possibility of explicitly modelling mesoscale uctuations in a mesoscale model is then examined using the weatherresearch and forecasting (WRF) model. A set of case studies demonstrate that realistic hour-scale wind uctuations and open cellular convection patterns develop in WRF simulations with 2km horizontal grid spacing. The atmospheric conditions during one of the case studies are then used to initialise a simplied version of the model that has no large scale weather forcing, topography or surface inhomogeneties. Using the simplied model, the sensitivity of the modelled open cellular convection to choices in model setup and to aspects of the environmental forcing are tested. Finally, the cell-scale kinetic energy budget of the modelled cells is calculated, and it is shown that the buoyancy and pressure balance terms are important for cell maintenance. It is explained that the representation of mesoscale convection in a mesoscale model is not only important to end users such as wind farm operators, but to the treatment of energy transport within the boundary layer.

  11. Banktop responses to Quaternary fluctuations in sea level recorded in periplatform sediments

    Science.gov (United States)

    Boardman, Mark R.; Neumann, A. Conrad; Baker, Paul A.; Dulin, Lise A.; Kenter, Richard J.; Hunter, Gerhart E.; Kiefer, Karen B.

    1986-01-01

    Periplatform sediment from a 12-m core recovered from Northwest Providence Channel, Bahamas, contains a geochemical and paleontological record of sea-surface temperatures, ice volumes, and the response of banktops to highstands of sea level. A comparison of these data suggests that fluctuations of carbonate mineralogy in periplatform sediments result from fluctuations of sea level and from patterns of banktop sedimentation. Highstands of sea level that flood carbonate platforms are recorded in periplatfonn sediments as abrupt increases of exported Sr-rich aragonite derived from banktop orgiuiisms superposed on a background of Sr-poor aragonite (pteropods) and calcite (foraminifera and coccoliths) derived from planktonic sources. The pulses of banktop sediment coincide with increases of water temperature determined from foraminiferal assemblages and with decreases in ratios of oxygen isotopes, indicating decreased ice volume and rising sea level. Following these abrupt changes is a more gradual decline in bank-derived sediment, although paleotemperatures from foraminiferal assemblages and oxygen isotopic data clearly show that warm conditions and a highstand of sea level persist. We suggest that this decrease of offbank transport is part of autocyclic sedimentation patterns of shallow-water carbonate environments. Offbank transport is restricted as reefs, sand shoals, and islands reach sea level. Also, green algal production may decline because progradation of tidal flats decreases lagoon area, and the hydrologic and ecologic conditions change as lagoons are filled.

  12. Low level activity determination by means of gamma spectrometry with respect to the natural background fluctuation

    International Nuclear Information System (INIS)

    The determination of low level activities of natural radionuclides from the uranium and thorium series by gamma-spectrometry faces the problem of proper natural background subtraction. Background fluctuation can cause differences in activity determination. Also the minimum detectable activity (MDA) of natural and artificial radionuclides can be influenced by background fluctuation. In this paper, results of the background fluctuation of shielded HPGe detectors with relative efficiency of 50–150% are presented together with the assessment of its influence on the determination of natural and artificial radionuclides. - Highlights: • Long term study of background peaks and integral counts. • Background fluctuation cause differences in low level activity determination. • Background fluctuation influence MDA calculation

  13. Structural Fluctuation of Protein in Water around Its Native State: A New Statistical Mechanics Formulation

    CERN Document Server

    Kim, Bongsoo

    2012-01-01

    A new statistical mechanics formulation of characterizing the structural fluctuation of protein correlated with that of water is presented based on the generalized Langevin equation and the 3D-RISM/RISM theory of molecular liquids. The displacement vector of atom positions and their conjugated momentum, are chosen for the dynamic variables for protein, while the density fields of atoms and their momentum fields are chosen for water. Projection of other degrees of freedom onto those dynamic variables using the standard projection operator method produces essentially two equations which describe the time evolution of fluctuation concerning the density field of solvent and the conformation of protein around an equilibrium state, which are coupled with each other. The equation concerning the protein dynamics is formally akin to that of the coupled Langevin oscillators, and is a generalization of the latter, to atomic level. The most intriguing feature of the new equation is that it contains the variance-covarianc...

  14. Experimental and Modeling Investigation of Shallow Water Table Fluctuations in Relation to Reverse Wieringermeer Effect

    Directory of Open Access Journals (Sweden)

    Ibrahimi Mohamed Khaled

    2011-09-01

    Full Text Available Soil column experiments and modeling investigations were performed to study the behavior of shallow water table in response to various recharge events. Hence, shallow water table fluctuations inside sandy (Toyoura sand and clayey (Chiba light clay soil columns in response to surface and sub-surface recharge events were investigated under laboratory conditions. Experimental results showed that small application of water could raise the shallow water table level more than 100 times in depth in the case of Toyoura sand and more than 50 times in the case of Chiba LiC, reflecting a reverse Wieringermeer effect (RWE response type of groundwater. This rise was associated with a prompt change of pressure head values which exhibited instantaneous fluctuations of centimeters due to the addition of millimeters of water. The recharge volumes leading to such disproportionate water table rise were successfully estimated using a simple analytical model based on the moisture retention curve of the soil and considering the hysteresis effect on soil water dynamics within the capillary fringe zone.

  15. Observed coherency in the seasonal sea level fluctuations along the coastline of the Indian subcontinent

    Digital Repository Service at National Institute of Oceanography (India)

    Srinivas, K.; DineshKumar, P.K.; Ravichandran, C.

    2007-01-01

    Seasonal sea level fluctuations result from oceanographic, meteorological and hydrological forcings. The largest seasonal signals of sea level, however, are primarily caused by hydrological forcings. The climatological seasonal cycles of pressure...

  16. Water level influences on body condition of Geophagus brasiliensis (Perciformes: Cichlidae) in a Brazilian oligotrophic reservoir

    OpenAIRE

    Alejandra Filippo Gonzalez Neves dos Santos; Luciano Neves dos Santos; Francisco Gerson Araújo

    2004-01-01

    Effects of water level fluctuations on body condition of Geophagus brasiliensis were studied in a 30 km² Brazilian oligotrophic reservoir. Physiological condition (K) and gonadosomatic index (GSI) were compared according to water level (low and high). Females' best conditions were associated to higher resources availability during high water, since gonad development did not change between low and high water. Males' condition did not change between water levels, while the highest gonad develo...

  17. Investigation of free level fluctuations in a simulated model of a sodium cooled Fast Breeder Reactor using pulsating conductance monitoring device

    International Nuclear Information System (INIS)

    Highlights: ? An innovative approach for measurement of water level fluctuation is presented. ? Measurement was conducted with a PC based pulsating type level sensor. ? Deployed the technique in monitoring level fluctuation in PFBR simulated facility. ? The technique helped in validation of hot pool design of PFBR, India. - Abstract: A high resolution measurement technique for rapid and accurate monitoring of water level using an in-house built pulsating conductance monitoring device is presented. The technique has the capability of online monitoring of any sudden shift in water level in a reservoir which is subjected to rapid fluctuations due to any external factor. We have deployed this novel technique for real time monitoring of water level fluctuations in a specially designed ¼ scale model of the Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, India. The water level measurements in various locations of the simulated test facility were carried out in different experimental campaigns with and without inclusion of thermal baffles to it in specific operating conditions as required by the reactor designers. The amplitudes and the frequencies of fluctuations with required statistical parameters in hot water pool of the simulated model were evaluated from the online time versus water level plot in more convenient way using system software package. From experimental results it is computed that the maximum free level fluctuation in the hot pool of PFBR with ban in the hot pool of PFBR with baffle plates provided on the inner vessel is 30 mm which is considerably less than the value (?82 mm) obtained without having any baffle plates. The present work provided useful information for assessment of appropriate design which would be adopted in the PFBR for safe operation of the reactor.

  18. Fluctuation properties of nuclear energy levels: Do theory and experiment agree

    International Nuclear Information System (INIS)

    The fluctuation properties of nuclear energy levels with new spectrally averaged measures are analyzed. A remarkably close agreement between the predictions of random-matrix theories and experiment is found

  19. Fluctuation properties of nuclear energy levels and widths: comparison of theory with experiment

    International Nuclear Information System (INIS)

    We analyze the fluctuation properties of nuclear energy levels and widths with new spectrally averaged measures. A remarkably close agreement between the predictions of random-matrix theories and experiment is found

  20. Memorization of short-range potential fluctuations in Landau levels

    International Nuclear Information System (INIS)

    We calculate energy spectra of a two-dimensional electron system in a perpendicular magnetic field and periodic potentials of short periods. The Coulomb interaction is included within a screened Hartree-Fock approximation. The electrostatic screening is poor and the exchange interaction amplifies the energy dispersion. We obtain, by numerical iterations, self-consistent solutions that have a hysteresis-like property. With increasing amplitude of the external potential the energy dispersion and the electron density become periodic, and they remain stable when the external potential is reduced to zero. We explain this property in physical terms and speculate that a real system could memorize short-range potential fluctuations after the potential has been turned off. (author)

  1. The National Water Level Observation Network

    National Oceanic and Atmospheric Administration, Department of Commerce — The fundamental observational component of the National Water Level Program (NWLP) is the National Water Level Observation Network (NWLON). The NWLON is a network...

  2. Why is the CMB fluctuation level $10^{-5}$?

    CERN Document Server

    Tegmark, M; Tegmark, Max; Rees, Martin

    1998-01-01

    We explore the qualitative changes that would occur if the amplitude Q ~ 10^{-5} of cosmological density fluctuations were different. If is less than about 10^{-6}, the cosmological objects that form would have so low virial temperatures that they may be unable to cool and form stars, and would be so loosely bound that even if they could produce a supernova explosion, they might be unable to retain the heavy elements necessary for planetary life. If Q is greater than about 10^{-4}, dense supermassive galaxies would form, and biological evolution could be marred by short disruption timescales for planetary orbits. If Q were still larger, most bound systems would collapse directly to supermassive black holes. These constraints on Q can be expressed in terms of fundamental constants alone, and depend only on the electromagnetic and gravitational coupling constants, the electron-proton mass ratio and the matter-to-photon ratio. We discuss the implications for inflation and defect models, and note that the recent ...

  3. Fluctuation of the water environmental carrying capacity in a huge river-connected lake.

    Science.gov (United States)

    Wang, Hua; Zhou, Yiyi; Tang, Yang; Wu, Mengan; Deng, Yanqing

    2015-04-01

    A new method, with the non-fully mixed coefficient (NFMC) considered, was put forward to calculate the water environmental carrying capacity (WECC) for huge river-connected lakes, of which the hydrological conditions always vary widely during a year. Poyang Lake, the most typical river-connected lake and the largest freshwater lake in China, was selected as the research area. Based on field investigations and numerical simulation, the monthly pollutant degradation coefficients and non-fully mixed coefficients of different lake regions were determined to explore the WECCs of COD, TN and TP of Poyang Lake in a common water year. It was found that under the hydrological conditions of a common water year the total WECCs of COD, TN and TP in the lake were respectively 181.9 × 104 t, 33.3 × 104 t and 1.86 × 104 t. Due to the varied lake water volume and self-purification ability, an evident temporal fluctuation of WECCs in Poyang Lake was observed. The dry seasons were characterized by a higher NFMCs but lower WECCs owing to the lower water level and degradation ability. Variation coefficients of COD and TN WECC were close to each other, of which the average level was about 58.5%, a little higher than that of TP. PMID:25830284

  4. Can the role of the tectonic-related processes be excluded on the Caspian Sea level fluctuations?

    Science.gov (United States)

    Ozyavas, A.; Khan, S. D.

    2009-12-01

    The Caspian Sea is the largest isolated reservoir in the world and located between Russia, Azerbaijan, Iran, Turkmenistan, and Kazakhstan. Its sea level is 27 meter below the mean sea level of the world oceans. Large sea level fluctuations have been recorded during its history and the reasons of these sea level variations have long been examined. While several authors attribute sea level oscillations to hydroclimatic change in the basin, some suggested that the activities associated with tectonism in the basin could have potential on hydrologic budget of the CS. The water balance of the CS from 1998 to 2005 is calculated. Evaporation is quite significant in water budget calculations in the CS due to the fact that almost all of the water input is compensated by the evaporation itself and that discharge to Kara Bogaz Gol bay is relatively small. We utilize NCEP/DOE Reanalysis II meteorological data to estimate evaporation over the CS by using Penman method. Tropical Rainfall Measuring Mission (TRMM) is the source for computing the direct precipitation on the sea surface. The Volga River is the main water source to it and 80 % of the total inflow to it has been provided via rivers. Total river runoff data along with discharge to KBG bay have been obtained from Geophysical Center of Russian Academy of Science (RAS). Even though Volga river discharge is usually of a high correlation with the sea level rise and drop until 2001, precipitation over the CS together with the contribution of the rest of the rivers has also strong influence over the sea level fluctuations for the rest of the years. Our results reveal that sea level changes from 1998 to 2005 are essentially controlled by meteorological factors. However, geological processes (groundwater outflow and inflow, mud volcanoes, tectonic activity) should be included to the water budget calculations of the CS.

  5. The fluctuations of Lago Maggiore levels in a regulated regime consideration on low water events (Le fluttuazioni di livello del Lago Maggiore in regime regolato: considerazioni sugli eventi di magra)

    OpenAIRE

    Luigi BARBANTI; Walter AMBROSETTI; Angelo ROLLA

    2007-01-01

    Lago Maggiore, due to the elevation and morphological nature of its drainage basin and to its location in a high precipitation climatic zone with a great inter-annual variability, is a water body with a high hydrogeological risk in that it is subject to floods and low water episodes that can be long-lasting. This last aspect, rather neglected in the previous studies, poses a serious risk for the communities on the shoreline and also for the use of the water resources for the irrigation of a w...

  6. Coherent sea-level fluctuations along the global continental slope

    OpenAIRE

    Hughes, Chris W.; Meredith, Michael P.

    2006-01-01

    Signals in sea-level or, more properly, sub-surface pressure (SSP; sea-level corrected for the inverse barometer effect) are expected to propagate rapidly along the continental slope due to the effect of sloping topography on wave modes, resulting in strongly correlated SSP over long-distances. Observations of such correlations around the Arctic and Antarctic are briefly reviewed, and then extended using satellite altimetry to the rest of the global continental slope. It is shown that such lo...

  7. Does temperature affect the accuracy of vented pressure transducer in fine-scale water level measurement?

    Science.gov (United States)

    Liu, Z.; Higgins, C. W.

    2015-03-01

    Submersible pressure transducers have been utilized for collecting water level data since the early 1960s. Together with a digital data logger, it is a convenient way to record water level fluctuations for long-term monitoring. Despite the wide use of pressure transducers for water level monitoring, little has been reported regarding their accuracy and performance under field conditions. The effects of temperature fluctuations on the output of vented pressure transducers were considered in this study. The pressure transducers were tested under both laboratory and field conditions. The results of this study indicate that temperature fluctuation has a strong effect on the transducer output. Rapid changes in temperature introduce noise and fluctuations in the water level readings under a constant hydraulic head while the absolute temperature is also related to sensor errors. The former is attributed to venting and the latter is attributed to temperature compensation effects in the strain gauges. Individual pressure transducers responded differently to the thermal fluctuations in the same testing environment. In the field of surface hydrology, especially when monitoring fine-scale water level fluctuations, ignoring or failing to compensate for the temperature effect can introduce considerable error into pressure transducer readings. It is recommended that a performance test for the pressure transducer is conducted before field deployment.

  8. Water Density Fluctuations Relevant to Hydrophobic Hydration are Unaltered by Attractions

    CERN Document Server

    Remsing, Richard C

    2014-01-01

    An understanding of density fluctuations in bulk water has made significant contributions to our understanding of the hydration and interactions of idealized, purely repulsive hydrophobic solutes. To similarly inform the hydration of realistic hydrophobic solutes that have dispersive interactions with water, here we characterize water density fluctuations in the presence of attractive fields that correspond to solute-water attractions. We find that when the attractive field acts only in the solute hydration shell, but not in the solute core, it does not significantly alter water density fluctuations in the solute core region. We further find that for a wide range of solute sizes and attraction strengths, the free energetics of turning on the attractive fields in bulk water are accurately captured by linear response theory. Our results also suggest strategies for more efficiently estimating hydration free energies of realistic solutes in bulk water and at interfaces.

  9. Characterization of the level fluctuations in a physical model of the steel continuous casting mold through image processing

    Scientific Electronic Library Online (English)

    J.R., Miranda-Tello; F., Sánchez-Rangel; C.A., Real-Ramírez; G., Khatchatourov; J.A., Aragón-Lezama; L.F., Hoyos-Reyes; E.A., Andrade-González; J.I., González-Trejo.

    2012-04-01

    Full Text Available In this work is characterized the periodic behavior of the liquid level inside a scaled cold-model of the mold section of a steel continuous casting machine, which uses water as working fluid. The models are designed in order to simulate the dynamic forces acting on the molten steel inside a mold of [...] continuous casting. The force magnitude can induce choppy flow, waves and vortex formation in the mold. The experimental model uses a closed-loop hydraulic configuration. In the mold, the inlet and the outlet water flow rates are the same. This configuration resembles a perfect control of the liquid level inside the water model. A high-speed video camera was used to get several video clips of the movement of the water level profile. Several techniques were tested in order to obtain the best lighting conditions for recording the water movement. The edge-detection technique of Sobel was used to determine the profile of the liquid level in each one of the images recorded. The analysis of the dynamic behavior of the water profile showed that the fluctuations of the liquid level inside the mold have a complex structure, which is repeated over large time periods.

  10. Numerical simulation of the impacts of water level variation on water age in Dahuofang Reservoir

    Science.gov (United States)

    Li, Xinwen; Shen, Yongming

    2015-06-01

    The transport timescales were investigated in response to water level variation under different constant flow rates in Dahuofang Reservoir. The concept of water age was applied to quantify the transport timescales. A three-dimensional hydrodynamic model was developed based on the Environmental Fluid Dynamics Code (EFDC). The model was calibrated for water surface elevation and temperature profiles from April 1, 2008 to October 31, 2008. Comparisons of observed and modeled data showed that the model reproduced the water level fluctuation and thermal stratification during warm season and vertical mixing during cold season fairly well. The calibrated model was then applied to investigate the response of water age to water level changes in Dahuofang Reservoir. Model results showed that water age increases from confluence toward dam zone. In the vertical direction, the water age is relatively uniform at upstream and stratifies further downstream, with a larger value at bottom layer than at surface layer. Comparisons demonstrated that water level variation has a significant impact on transport timescales in the reservoir. The impact of water level drawdown on water age is stronger at bottom layer than at surface layer. Under high flow conditions, the water age decreases 0-20 days at surface layer and 15-25 days at bottom layer. Under mean flow conditions, the water age decreases 20-30 days at surface layer and 30-50 days at bottom layer. Furthermore, the impact is minor in the upstream and increases further downstream. The vertical stratification of water age weakens as the water level decreases. This study provides a numerical tool to quantify the transport timescale in Dahuofang Reservoir and supports adaptive management of regional water resources by local authorities.

  11. Stabilizing the domestic price level under fluctuating terms of trade

    OpenAIRE

    Gerken, Egbert

    1983-01-01

    In this paper a general equilibrium model of Chile will be applied to quantify (a) the requirements for real exchange rate stabilization in a commodity exporting country, (b) the implications of nominal exchange rate and price level stabilization, and (c) short-run benefits and long-run costs of using compensatory finance. The analysis will be done under conditions of both a closed and an open capital account. The recent Chilean experience, which will be sketched in chapter II, provides an al...

  12. Changes in climate, catchment vegetation and hydrogeology as the causes of dramatic lake-level fluctuations in the Kurtna Lake District, NE Estonia

    OpenAIRE

    Marko Vainu; Jaanus Terasmaa

    2014-01-01

    Numerous lakes in the world serve as sensitive indicators of climate change. Water levels for lakes Ahnejärv and Martiska, two vulnerable oligotrophic closed-basin lakes on sandy plains in northeastern Estonia, fell more than 3 m in 1946–1987 and rose up to 2 m by 2009. Earlier studies indicated that changes in rates of groundwater abstraction were primarily responsible for the changes, but scientifically sound explanations for water-level fluctuations were still lacking. Despite the inconsis...

  13. Changes in climate, catchment vegetation and hydrogeology as the causes of dramatic lake-level fluctuations in the Kurtna Lake District, NE Estonia

    Directory of Open Access Journals (Sweden)

    Marko Vainu

    2014-02-01

    Full Text Available Numerous lakes in the world serve as sensitive indicators of climate change. Water levels for lakes Ahnejärv and Martiska, two vulnerable oligotrophic closed-basin lakes on sandy plains in northeastern Estonia, fell more than 3 m in 1946–1987 and rose up to 2 m by 2009. Earlier studies indicated that changes in rates of groundwater abstraction were primarily responsible for the changes, but scientifically sound explanations for water-level fluctuations were still lacking. Despite the inconsistent water-level dataset, we were able to assess the importance of changing climate, catchment vegetation and hydrogeology in water-level fluctuations in these lakes. Our results from water-balance simulations indicate that before the initiation of ground­water abstraction in 1972 a change in the vegetation composition on the catchments triggered the lake-level decrease. The water-level rise in 1990–2009 was caused, in addition to the reduction of groundwater abstraction rates, by increased precipitation and decreased evaporation. The results stress that climate, catchment vegetation and hydrogeology must all be considered while evaluating the causes of modern water-level changes in lakes.

  14. Relationship between fluctuations in glucose levels measured by continuous glucose monitoring and vascular endothelial dysfunction in type 2 diabetes mellitus

    OpenAIRE

    Torimoto Keiichi; Okada Yosuke; Mori Hiroko; Tanaka Yoshiya

    2013-01-01

    Abstract Background Fluctuations in blood glucose level cause endothelial dysfunction and play a critical role in onset and/or progression of atherosclerosis. We hypothesized that fluctuation in blood glucose levels correlate with vascular endothelial dysfunction and that this relationship can be assessed using common bedside medical devices. Methods Fluctuations in blood glucose levels were measured over 24?hours by continuous glucose monitoring (CGM) on admission day 2 in 57 patients with...

  15. Solute Transport Under Water Table Fluctuations in a Fine Sand and a Sandy Clay Loam Soil

    Directory of Open Access Journals (Sweden)

    Cesáreo Landeros-Sánchez

    2013-12-01

    Full Text Available Drainage contributes to removing the excess of water from cultivated land. In general, most common drainage systems lead to loss of fertilizers applied for plant growth and yield improvement. Thus, the main objective of this work was to study experimentally the redistribution of solutes within the soil profile caused by water table fluctuations by making use of a non-reactive tracer in laboratory studies on soil columns. Two soil materials, namely fine sand and a sandy clay loam soil, were used in this study. Use was made of potassium chloride as a non-reactive tracer. Profiles of chloride redistribution as a function of depth caused by a first drainage of a saturated column with chloride in the surface layer, sub-irrigation and a second drainage were obtained for the fine sand columns with draining water levels at depths 25.5 and 44.5 cm, and for the sandy clay loam columns with a draining water level at depth 44.5 cm. Although only results for water table depth at 44.5 cm for both soils materials are presented. The redistribution of chloride in both the fine sand and the sandy clay loam columns was dominantly attributed to convective movement of solutes and was considered to be little influenced by diffusion. Preferential flow could have taken place through large sized pores of the fine sand columns. The knowledge and data of this study is a contribution towards that needed to define operation strategies for sub-irrigation-drainage systems which can lead to optimize fertilizers use by crops.

  16. Model of m-level low-frequency current fluctuations in metal thermionic cathodes

    International Nuclear Information System (INIS)

    A new model of low-frequency fluctuations, based on the thermionic current model [Mathematical Handbook for Scientists and Engineers, New York, 1961; Introduction to Statistical Radio-Physic. Part 1: Random Processes, Moscow, 1976 (in Russian)], has been designed. The proposed model provides calculation of realization, auto-correlation function (ACF) and power spectral density (PSD) of an m-level quantum signal. This model has allowed to explain the reason of very small magnitude of low-frequency (LF) boundary (10-4 to 10-2 Hz) on experimental spectra of LF current fluctuations in a metal thermionic cathodes

  17. Water Table Fluctuation in Tidal Lowland for Developing Agricultural Water Management Strategies

    Directory of Open Access Journals (Sweden)

    Momon Sodik Imanudin

    2010-09-01

    Full Text Available The research objective is to evaluate the water status in the tertiary block of tidal lowland for developing water management strategies and cropping pattern for food crop agriculture. The research was conducted in tidal lowland reclamation areas of Delta Saleh South Sumatera. The methodology used in this research was survey and monitoring. The result showed that the study area has a potential of acid sulphate soil which is indicated by phyrite layer at 60 cm below the soil surface. Variation of water table was very high in the range of 0-2 cm at rainy season and it was drop up to 90 to 100 cm below soil surface at dry season. This conditions result in the soil oxidation and the pH drop up to 2.5-3.5 (very acid. Analysis of water surplus and deficit during one year period was calculated by surplus excess water under 30 cm (SEW-30 and showed that the area study was experienced water deficit. Analysis of groundwater effect on soil moisture content showed that the critical water level was in 60 cm below soil surface. The soil moisture content at this point in the root zone was dropped into the wilting point level. It means that the water availability for crop water requirement is inadequate. For sustainable agriculture in the area study, the water table should be maintained in 50-60 cm below soil surface. Therefore, the recommendation of water management strategies in the study area is water retention in combination with control drainage system.

  18. Water levels in continuously monitored wells in the Yucca Mountain area, Nevada, 1985--88

    International Nuclear Information System (INIS)

    Water levels have been monitored hourly in 15 wells completed in 23 depth intervals in the Yucca Mountain area, Nevada. Water levels were monitored using pressure transducers and were recorded by data loggers. The pressure transducers were periodically calibrated by raising and lowering them in the wells. The water levels were normally measured at approximately the same time that the transducers were calibrated. Where the transducer output appeared reasonable, it was converted to water levels using the calibrations and manual water- level measurements. The amount of transducer output that was converted to water levels ranged from zero for several intervals to about 98 percent for one interval. Fourteen of the wells were completed in Tertiary volcanic rocks and one well was completed in Paleozoic carbonate rocks. Each well monitored from one to four depth intervals. Water-level fluctuation caused by barometric pressure changes and earth tides were observed

  19. Methods of measuring water levels in deep wells

    Science.gov (United States)

    Garber, M.S.; Koopman, F.C.

    1968-01-01

    Accurate measurement of water levels deeper than 1,000 feet in wells requires specialized equipment. Corrections for stretch and thermal expansion of measuring tapes must be considered, and other measuring devices must be calibrated periodically. Bore-hole deviation corrections also must be made. Devices for recording fluctuation of fluid level usually require mechanical modification for use at these depths. A multichannel recording device utilizing pressure transducers has been constructed. This device was originally designed to record aquifer response to nearby underground nuclear explosions but can also be used for recording data from multi-well pumping tests. Bottom-hole recording devices designed for oil-field use have been utilized in a limited manner. These devices were generally found to lack the precision required, in ground-water investigations at the Nevada Test Site but may be applicable in other areas. A newly developed bottom-hole recording pressure gauge of improved accuracy has been used with satisfactory results.

  20. Uvigerina from Laminated Sediments may Record Bottom Water Nutrient Levels

    Science.gov (United States)

    Marchitto, T. M.; Carriquiry, J.; Ortiz, J. D.; van Geen, A.

    2001-05-01

    It has long been recognized that ? 13C values in the benthic foraminiferal genus Uvigerina are typically about 1 per mil lower than those of Cibicidoides wuellerstorfi. This offset has been attributed to the shallow infaunal habitat of Uvigerina (causing it to record ? 13C-depleted pore waters) relative to the epifaunal habitat of C. wuellerstorfi (recording more enriched bottom waters). In laminated (low-oxygen) sediments, Cibicidoides are absent because of their relatively high oxygen requirement, leaving Uvigerina as probably our best chance at reconstructing bottom water nutrient levels. We have measured Uvigerina ? 13C in an intermediate-depth (700 m) core from the oxygen minimum zone on the Baja California margin. This high sedimentation rate core ( ~30 cm/kyr) displays percent organic carbon fluctuations that bear a striking resemblance to Greenland air temperatures over the past 50 kyr. Warmer periods correspond to higher organic carbon levels, and extremes (including the Holocene and several interstadials) are laminated. Somewhat surprisingly, ? 13C is highest during the Holocene, with values ( ~ -0.3 to 0 per mil) close to modern bottom water estimates. We hypothesize that bottom water and pore water oxygen levels were so low during the Holocene that Uvigerina migrated toward the sediment-water interface and actually recorded bottom water ? 13C. We are currently measuring Uvigerina trace metals (Cd/Ca and Zn/Ca) for comparison. A complication is that the trace metals could be influenced not only by Cd and Zn concentrations in the pore waters, but by the saturation state of those pore waters (through its influence on trace metal partition coefficients). Alternatively the trace metals may be under little pore water influence, as has been suggested previously. Although downcore variations in Uvigerina ? 13C are likely dominated (in this fluctuating-oxygen environment) by microhabitat migrations, it may be possible to infer at what times it is living at/near the surface, perhaps by measuring the abundance of dysoxic species in the benthic assemblage.

  1. Periodic fluctuations in deep water formation due to sea ice

    CERN Document Server

    Saha, Raj

    2015-01-01

    During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural p...

  2. The fluctuating political appeal of water engineering in Australia

    OpenAIRE

    Lin R. Crase; Suzanne M. O’Keefe; Brian E. Dollery

    2009-01-01

    Like many nations, Australia has a mixed history with water engineering. For over a century the engineer was 'king' and water was harnessed as a vehicle for settling the harsh inland, creating wealth and building prosperity. By the 1960s it was becoming increasingly clear that this approach was not without its flaws. Mounting evidence of environmental degradation emerged in the 1970s and the trend towards fiscal responsibility in the 1980s subjected the engineering approach to even greater sc...

  3. Shallow Water Internal Waves and Associated Acoustic Intensity Fluctuations

    Directory of Open Access Journals (Sweden)

    P.V. Hareesh Kumar

    2006-10-01

    Full Text Available Physical oceanographic and acoustic data were simultaneously collected from the coastalwaters of the Arabian Sea. Acoustic transmissions were carried out from an anchored vesselusing 620 Hz transducer and received by an array of hydrophones moored at ~5 km away fromthe anchorage. Thermal structure in this region was characterised by a tri-layer structure, ie, astrong thermocline (> 0.4 oC/m sandwiched between an upper (< 10 m and bottom (> 25 mhomogeneous layer. High-resolution (sampled at 10 s interval temperature data from mooredsensors revealed intense internal wave activity. The maximum value of Brunt-Vaisala frequency,which is the maximum frequency limit of internal waves in the thermocline, suggests that theupper frequency limit of the internal wave, which can be generated during this period, is 23 cph(2.6 min. High and low frequency waves caused variations of ~3 oC and ~5 oC respectively inthe temperature field. But the low frequency internal waves were found to contain maximumenergy compared to the high frequency waves. Fluctuations of 8-12 dB were noticed in themeasured acoustic intensity values in the presence of low frequency internal waves. Simulationstudies carried out using parabolic equation model using 620 Hz source indicated well-definedducted propagation with minimum transmission loss, when the source was kept within thehomogeneous layer. The presence of tri-layer thermal structure, ie, a strong gradient layersandwiched between an upper and bottom homogeneous layer, caused surface and bottom channelpropagation in this region.

  4. Modeling Tidal Water Levels for Canadian Coastal and Offshore waters

    Science.gov (United States)

    Robin, C. M. I.; MacAulay, P.; Nudds, S.; Godin, A.; de Lange Boom, B.; Bartlett, J.; Maltais, L.; Herron, T.; Craymer, M. R.; Veronneau, M.; Fadaie, K.

    2014-12-01

    IIn 2010, the Canadian Hydrographic Service initiated the Continuous Vertical Datum for Canadian Waters (CVDCW) project, the aim of which is to connect tidal water level datums (high and low water levels, chart datum, etc.) to a national geodetic reference frame over all Canadian tidal waters. Currently, water level datums are tied to a geodetic reference frame at approximately 400 tide stations which have been surveyed with GPS, whereas water levels vary significantly in space even a short distance away from tide stations. The CVDCW captures the relevant spatial variability between stations and offshore by integrating ocean models, gauge data (water level analyses and/or GPS observations), sea level trends, satellite altimetry, and a geoid model. The CVDCW will enable the use of Global Navigation Satellite System technologies (primarily GPS) for hydrographers and navigators. It will also be important for other users including oceanographers, environmental and climate scientists, surveyors and engineers. For instance, it will allow easier integration of hydrographic and terrestrial data, provide a baseline for storm surge modeling and climate change adaptation, and aid with practical issues such as sovereignty and the definition of the coastline. Once high and low water surfaces are complete, they will define a large portion of the vertical link between land and ocean, helping to delineate flooding thresholds and inter-tidal ecosystem zones and boundaries. Here we present an overview of the methodology using a set of prototype model results, and will outline features of interest for studies in coastal stability, climate change adaptation, and sea level change.

  5. Early Pleistocene sea level and millennial-scale climate fluctuations: a view from the tropical Pacific

    Science.gov (United States)

    Alix Jakob, Kim; Friedrich, Oliver; Pross, Jörg

    2015-04-01

    This project aims at deciphering the rate of sea level variability and its effect on millennial-scale climate fluctuations during the final phase of the intensification of northern hemisphere glaciation (NHG). Millennial-scale climate fluctuations appear to have changed significantly at glacial-interglacial time scales during the late Pliocene and Pleistocene. Thereby, millennial-scale climate fluctuations under a warmer climate during late Pliocene and early Pleistocene show markedly lower ampitudes compared to the fluctuations of the late Pleistocene. Numerous Pleistocene proxy records (e.g. McManus et al., 1999) suggest that this difference can be explained by an ice-volume/sea-level threshold that amplifies millennial-scale climate fluctuations and was not reached prior to the Mid-Pleistocene Transition (MPT). However, new records question the existence of this threshold (Bolton et al., 2010) and indicate that either the amplification of millennial-scale climate fluctuations before the MPT required a higher ice-volume threshold than in the late Pleistocene, that ice-volume had no significant effect on the amplitude of climate fluctuations, and/or the available sea level estimates for the early Pleistocene are inaccurate. For identifying the mechanisms underlying the dynamics of early Pleistocene ice sheets, material from the tropical Pacific Ocean (ODP Site 849) is studied over a time interval from 2.6 to 2.4 Ma (marine isotope stages 104 to 96). In summary, the main deliverables are (1) the establishment of a precise ?18O chemostratigraphy using the benthic foraminifera Cibicidoides wuellerstorfi by tuning the ?18O dataset to the LR04 benthic isotope stack (Lisiecki & Raymo, 2005), and (2) providing high-resolution (˜700 years) Mg/Ca and ?18O datasets using the benthic foraminifera Oridorsalis umbonatus and the planktonic foraminifera Globigerinoides ruber. This combined geochemical approach will be used to address the following research questions: (1) Quantification of sea level change from 2.6 to 2.4 Ma; (2) Critically assess the hypothesis of an ice-volume threshold for millennial-scale climate amplification during the early Pleistocene (and if it exists, what its value was); (3) Detailed comparison with late Pleistocene glacials; (4) Model-data comparison to assess the fidelity of model-based sea level estimates; and (5) reconstruction of sea surface temperature fluctuations of the tropical Pacific. References Bolton, C.T., Wilson, P.A., Bailey, I., Friedrich, O., Beer, C.J., Becker, J., Baranwal, S., Schiebel, R. (2010): Millennial-scale climate variability in the subpolar North Atlantic Ocean during the late Pliocene. Paleoceanography 25, doi:10.1029/2010PA001951. Lisiecki, L.E. & Raymo, M.E. (2005): A Pliocene-Pleistocene stack of 57 globally distributed benthic ?18O records. Paleoceanography 20, doi:10.1029/2004PA 001071. McManus, J., Oppo, D.W., Cullen, J.L. (1999): A 0.5-Million-Year Record of Millenial-Scale Climate Variability in the North Atlantic. Science 283, 971-975.

  6. Prediction of seasonal water-table fluctuations in La Pampa and Buenos Aires, Argentina

    Science.gov (United States)

    Tanco, Raúl; Kruse, Eduardo

    2001-07-01

    The fluctuation of the water table east of La Pampa province and northwest of Buenos Aires province, Argentina, influences agricultural production in the region because it is closely related to the alternation of dry and wet periods. Sea-surface temperature (SST) anomalies have been used as predictors to forecast atmospheric variables in different regions of the world. The objective of this work is to present a simple model to forecast seasonal rainfall using SST distribution in the Pacific Ocean as a predictor. Once the relationship between precipitation and water-table fluctuations was established, a methodology for the prediction of water-table fluctuations was developed. A good agreement between observed and predicted water-table fluctuations was found when estimating water-table fluctuations in the summer and autumn seasons. Résumé. Les fluctuations de la nappe à l'est de la province de La Pampa et au nord-ouest de la province de Buenos Aires (Argentine) influence la production agricole de la région parce qu'elle est étroitement liée à l'alternance de saisons sèches et humides. Les anomalies de la température de surface de l'océan (SST) ont été utilisées comme prédicteurs pour prévoir les variables atmosphériques dans différentes régions du monde. L'objectif de ce travail est de présenter un modèle simple de prévision des précipitations saisonnières en utilisant comme prédicteur la distribution des SST dans l'Océan Pacifique. Une fois que la relation entre les fluctuations des précipitations et celles de la nappe a été établie, une méthodologie de prédiction des variations de la nappe a été mise au point. Un bon accord entre les variations de la nappe observées et celles prédites a été trouvé pour les estimations des variations de nappe en été et en automne. Resumen. La fluctuación del nivel freático al este de la provincia de La Pampa y al nordeste de la de Buenos Aires (Argentina) repercute en la producción agrícola de la región, ya que está íntimamente relacionada con la alternancia de períodos secos y húmedos. Se ha utilizado las anomalías de la temperatura superficial del mar (TSM) para predecir las variables atmosféricas en diferentes áreas del mundo. El objetivo de este trabajo es presentar un modelo sencillo para pronosticar la precipitación estacional por medio de la distribución de TSM en el Océano Pacífico. Una vez establecida la relación entre la precipitación y las fluctuaciones del nivel freático, se desarrolló una metodología para predecir las fluctuaciones de éste. Se obtuvo un buen ajuste entre las fluctuaciones predichas y observadas del nivel freático en las estaciones de verano y otoño.

  7. Controlling the response of a pressurized water reactor to rapid fluctuations in load

    International Nuclear Information System (INIS)

    Apparatus for controlling the response to a load signal of a pressurized water reactor having controlled process variables is described. It consists of: a control system for effecting control actions to regulate a selected process variable to a value called for by a setpoint reference signal; and means responsive only to rapid fluctuations in the load signal above a predetermined frequency for adjusting the value of the setpoint reference signal by an amount which substantially matches the variation in the value of the selected process variable expected as a result of the rapid fluctuations in the load signal without control action, and taking into account any time delay in the affect of the rapid fluctuations on the selected process variable, whereby control actions effected by the control system are substantially reduced

  8. Effect of hysteresis on water flow in a sand column with a fluctuating capillary fringe

    Science.gov (United States)

    Lehmann, Peter; Stauffer, Fritz; Hinz, Christoph; Dury, Olivier; Flühler, Hannes

    1998-09-01

    The transport of water and solutes from the topsoil to groundwater is sensitive to the mixing regime near and within the capillary fringe. The capillary fringe is the transition zone between the saturated and unsaturated regions of the vadose zone. This study was conducted to describe variations of water content and matric potential in the presence of a capillary fringe. We used a sand column with a fluctuating water table to explore the dynamics of the phase distributions. A column 57 cm in length and 5.3 cm in diameter was packed with a sand mixture. The water pressure fluctuated at the bottom and forced the capillary fringe to move within the column. The column was installed on a balance for measuring the total water mass in it. Water content and potential were measured at different soil depths using TDR probes and tensiometers. The first series of experiments was conducted without irrigating. In a second series water was added to the surface at a constant rate by means of a sprinkling system. The variations of water content and matric potential were increasingly dampened and shifted in time with increasing distance from the capillary fringe. To describe the dynamics of water distribution it was necessary to account for hysteresis. Hysteresis dampened the water dynamics and caused a highly asymmetrical response of water content to the symmetrically oscillating lower boundary condition. The water dynamics were simulated with the computer code HYSTFLOW [Stauffer, F., 1996. Hysterestic unsaturated flow modelling. In: Proceedings of the Second International Conference on Hydroinformatics, Hydroinformatics '96, Zürich, Switzerland. Balkema, Rotterdam, pp. 589-595] which is based on Richards' equation, the Brooks and Corey hydraulic functions and a modified Mualem [Mualem, Y., 1984. A modified dependent-domain theory of hysteresis. Soil Sci. 137 (5), 283-291] hysteresis model. The water dynamics including the hysteretic behaviour were well described by the simulations.

  9. Discrete-storm water-table fluctuation method to estimate episodic recharge.

    Science.gov (United States)

    Nimmo, John R; Horowitz, Charles; Mitchell, Lara

    2015-01-01

    We have developed a method to identify and quantify recharge episodes, along with their associated infiltration-related inputs, by a consistent, systematic procedure. Our algorithm partitions a time series of water levels into discrete recharge episodes and intervals of no episodic recharge. It correlates each recharge episode with a specific interval of rainfall, so storm characteristics such as intensity and duration can be associated with the amount of recharge that results. To be useful in humid climates, the algorithm evaluates the separability of events, so that those whose recharge cannot be associated with a single storm can be appropriately lumped together. Elements of this method that are subject to subjectivity in the application of hydrologic judgment are values of lag time, fluctuation tolerance, and master recession parameters. Because these are determined once for a given site, they do not contribute subjective influences affecting episode-to-episode comparisons. By centralizing the elements requiring scientific judgment, our method facilitates such comparisons by keeping the most subjective elements openly apparent, making it easy to maintain consistency. If applied to a period of data long enough to include recharge episodes with broadly diverse characteristics, the method has value for predicting how climatic alterations in the distribution of storm intensities and seasonal duration may affect recharge. PMID:24588378

  10. The effect of interaural-level-difference fluctuations on the externalization of sound

    DEFF Research Database (Denmark)

    Catic, Jasmina; Santurette, Sébastien

    2013-01-01

    Real-world sound sources are usually perceived as externalized and thus properly localized in both direction and distance. This is largely due to (1) the acoustic filtering by the head, torso, and pinna, resulting in modifications of the signal spectrum and thereby a frequency-dependent shaping of interaural cues and (2) interaural cues provided by the reverberation inside an enclosed space. This study first investigated the effect of room reverberation on the spectro-temporal behavior of interaural level differences (ILDs) by analyzing dummy-head recordings of speech played at different distances in a standard listening room. Next, the effect of ILD fluctuations on the degree of externalization was investigated in a psychoacoustic experiment performed in the same listening room. Individual binaural impulse responses were used to simulate a distant sound source delivered via headphones. The ILDs were altered using a gammatone filterbank for analysis and resynthesis, where the envelopes of the left and right-ear signals were modified such that the naturally occurring fluctuations of the ILDs were restricted. This manipulation reduced the perceived degree of externalization. This was consistent with the analysis of short-term ILDs at different distances showing that a decreased distance to the sound source also reduced the ILD fluctuations. © 2013 Acoustical Society of America.

  11. Fluctuations in Species-Level Protein Expression Occur during Element and Nutrient Cycling in the Subsurface

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, Michael J.; Wrighton, Kelly C.; Nicora, Carrie D.; Williams, Kenneth H.; McCue, Lee Ann; Handley, Kim M.; Miller, C. S.; Giloteaux, L.; Montgomery, A. P.; Lovley, Derek R.; Banfield, Jillian F.; Long, Philip E.; Lipton, Mary S.

    2013-03-05

    While microbial activities in environmental systems play a key role in the utilization and cycling of essential elements and compounds, microbial activity and growth frequently fluctuates in response to environmental stimuli and perturbations. To investigate these fluctuations within a saturated aquifer system, we monitored a carbon-stimulated in situ Geobacter population while iron reduction was occurring, using 16S rRNA abundances and high-resolution tandem mass spectrometry proteome measurements. Following carbon amendment, 16S rRNA analysis of temporally separated samples revealed the rapid enrichment of Geobacter-like environmental strains with strong similarity to G. bemidjiensis. Tandem mass spectrometry proteomics measurements suggest high carbon flux through Geobacter respiratory pathways, and the synthesis of anapleurotic four carbon compounds from acetyl-CoA via pyruvate ferredoxin oxidoreductase activity. Across a 40-day period where Fe(III) reduction was occurring, fluctuations in protein expression reflected changes in anabolic versus catabolic reactions, with increased levels of biosynthesis occurring soon after acetate arrival in the aquifer. In addition, localized shifts in nutrient limitation were inferred based on expression of nitrogenase enzymes and phosphate uptake proteins. These temporal data offer the first example of differing microbial protein expression associated with changing geochemical conditions in a subsurface environment.

  12. Reading Ground Water Levels with a Smartphone

    Science.gov (United States)

    van Overloop, Peter-Jules

    2015-04-01

    Most ground water levels in the world are measured manually. It requires employees of water management organizations to visit sites in the field and execute a measurement procedure that requires special tools and training. Once the measurement is done, the value is jotted down in a notebook and later, at the office, entered in a computer system. This procedure is slow and prone to human errors. A new development is the introduction of modern Information and Communication Technology to support this task and make it more efficient. Two innovations are introduced to measure and immediately store ground water levels. The first method is a measuring tape that gives a sound and light when it just touches the water in combination with an app on a smartphone with which a picture needs to be taken from the measuring tape. Using dedicated pattern recognition algorithms, the depth is read on the tape and it is verified if the light is on. The second method estimates the depth using a sound from the smartphone that is sent into the borehole and records the reflecting waves in the pipe. Both methods use gps-localization of the smartphone to store the depths in the right location in the central database, making the monitoring of ground water levels a real-time process that eliminates human errors.

  13. Low level plutonium removal from surface waters

    International Nuclear Information System (INIS)

    Methods have been developed to remove low level (1-10,000 pCi/L) plutonium from surface waters and ponds at Rocky Flats Plant, Colorado. The process involves the combining of two existing technologies to accomplish removal levels that are enhanced over the separate methods. The first step is the addition of a fine clay to the water so that sorption of plutonium is accomplished. A variety of clay types were studied including montmorillinite, kaolinte, and bentonite. Most clays were able to remove Pu V and Pu VI. The second step is the addition of a flocculating agent to settle the fine clay particles so negative surface charge, a cationic flocculent was used. A commercial clay already containing flocculent was also studied. Since this mixture contained both the flocculent and the clay the process was reduced to a one step procedure. Both methods showed that this procedure could removed up to 97% of the soluble and colloidal plutonium from surface waters

  14. Averaged electrode voltages: management of electrode failures in children, fluctuating threshold and comfort levels, and otosclerosis.

    Science.gov (United States)

    Mens, L H; Brokx, J P; van den Broek, P

    1995-09-01

    Implant-generated surface potentials, or averaged electrode voltages (AEVs), were collected by means of the electrode-by-electrode (E-E) mapping variable mode strategy. Three topics were investigated. 1) Eighteen children under the age of 7 were tested and the E-E map of 4 of them was found deviant; all 4 children were deaf owing to meningitis. Some electrodes marked as failing by E-E mapping did not cause problems during device fitting, and electrodes not usable in device fitting showed normal AEVs in 1 child. Overall, the AEVs agreed well with abnormalities in the behavioral threshold (T) and comfort (C) levels. The E-E maps provided useful clues for the audiologist in most cases. 2) Repeated E-E mapping in 2 children who displayed large fluctuations over time of T levels suggested a fluctuation in (neural) responsiveness in 1 child and new bone formation in the other. 3) Although massive phase reversals of AEVs in 2 patients deafened by otosclerosis seemed to indicate a very permeable cochlear bone, stimulation in the pseudomonopolar mode across the basal turn did not affect T levels, and affected pitch perception in only 1 patient. Deviant AEVs from abnormal cochleas should, therefore, not be interpreted too easily as an indication of an electrode failure, faulty electrode placement, or inadequate tonotopy. PMID:7668620

  15. Geochemical Changes in the Caspian Salt Marshes Due to the Sea Level Fluctuations

    Directory of Open Access Journals (Sweden)

    Nicolay S. Kasimov

    2012-05-01

    Full Text Available The Caspian Sea is subject to alternating transgressions and regressions that exert a strong impact on the topography, sediments, vegetation, and soils in coastal zones. The last transgression of the Caspian Sea (1978-1995 caused the development of a marsh-lagoon system along the accumulative seashore of the Central Dagestan. Salt marshes are complex and dynamic systems highly vulnerable to sea level fluctuations; therefore, they may be considered as a regional model of rapid environmental changes. Hazards in coastal zones may critically change the soil geochemistry affecting agricultural potential of large areas. Assessments of risks of the natural hazards in coastal zones are extremely difficult unless the end-to-end understanding of all natural factors. The research in the Caspian region shows the impact of extreme events in the coastal zones. Detailed landscape-geochemical investigations of the Caspian salt marshes were carried out in 1995-1996 (during the final stage of the transgression period and in 2001-2003 (during the period of the sea level stabilization. These coastal areas are influenced by different landscape-geochemical processes, such as sulfidization, gleyzation, ferrugination, humus accumulation, halogenesis, and changes of alkali-acidic conditions. The development of the processes characterizes different stages of the Caspian Sea level fluctuations. This paper presents a discussion on stages and rates of landscape-geochemical processes, formation of geochemical barriers, and trace elements distribution in soils of the salt marshes.

  16. Drought impact on water use efficiency and intra-annual density fluctuations in Erica arborea on Elba (Italy).

    Science.gov (United States)

    Battipaglia, Giovanna; DE Micco, Veronica; Brand, Willi A; Saurer, Matthias; Aronne, Giovanna; Linke, Petra; Cherubini, Paolo

    2014-02-01

    Erica arborea (L) is a widespread Mediterranean species, able to cope with water stress and colonize semiarid environments. The eco-physiological plasticity of this species was evaluated by studying plants growing at two sites with different soil moistures on the island of Elba (Italy), through dendrochronological, wood-anatomical analyses and stable isotopes measurements. Intra-annual density fluctuations (IADFs) were abundant in tree rings, and were identified as the key parameter to understand site-specific plant responses to water stress. Our findings showed that the formation of IADFs is mainly related to the high temperature, precipitation patterns and probably to soil water availability, which differs at the selected study sites. The recorded increase in the (13) C-derived intrinsic water use efficiency at the IADFs level was linked to reduced water loss rather than to increasing C assimilation. The variation in vessel size and the different absolute values of ?(18) O among trees growing at the two study sites underlined possible differences in stomatal control of water loss and possible differences in sources of water uptake. This approach not only helped monitor seasonal environmental differences through tree-ring width, but also added valuable information on E.?arborea responses to drought and their ecological implications for Mediterranean vegetation dynamics. PMID:23848555

  17. Analysis and improvements of module incidental interference faults of water level control system pressurize NPP

    International Nuclear Information System (INIS)

    In Daya Bay nuclear power plant, there have been many times that the module used to value the water level outputs a small pulse interference when the pressurizer water level control system is in operation, and the interference exists only in analog storage operation module, which can directly impact the control of the water level of the pressurizer, causing the water level fluctuations and adversely affecting the safe operation of the reactor. This paper analyzes the module incidental interference faults of the water level control system of the NPP pressurizer from the point view of the system control and design of module hardware, and finds out the reasons by the system simulation experiment and power supply circuit test. It is suggested to further improve on the design of hardware loops, add more inductance and capacity to eliminate the interference. (authors)

  18. Arrival-time fluctuations of coherent reflections from surface gravity water waves.

    Science.gov (United States)

    Badiey, Mohsen; Eickmeier, Justin; Song, Aijun

    2014-05-01

    Arrival time fluctuations of coherent reflections from surface gravity waves are examined. A two-dimensional ray model with an evolving rough sea surface is used to explain the mechanism and formation of the deterministic striation patterns due to the surface reflection. Arrival time predictions from the ray model match qualitatively well with the measurements from bidirectional acoustic transmissions in a water depth of 100?m. PMID:24815293

  19. Statistical Derivation of the Evolution Equation of Liquid Water Path Fluctuations in Clouds

    OpenAIRE

    Ivanova, K.; Ausloos, Marcel

    2002-01-01

    How to distinguish and quantify deterministic and random influences on the statistics of turbulence data in meteorology cases is discussed from first principles. Liquid water path (LWP) changes in clouds, as retrieved from radio signals, upon different delay times, can be regarded as a stochastic Markov process. A detrended fluctuation analysis method indicates the existence of long range time correlations. The Fokker-Planck equation which models very precisely the LWP $fluc...

  20. Development and evaluation of a water level proportional water sampler

    Science.gov (United States)

    Schneider, P.; Lange, A.; Doppler, T.

    2013-12-01

    We developed and adapted a new type of sampler for time-integrated, water level proportional water quality sampling (e.g. nutrients, contaminants and stable isotopes). Our samplers are designed for sampling small to mid-size streams based on the law of Hagen-Poiseuille, where a capillary (or a valve) limits the sampling aliquot by reducing the air flux out of a submersed plastic (HDPE) sampling container. They are good alternatives to battery-operated automated water samplers when working in remote areas, or at streams that are characterized by pronounced daily discharge variations such as glacier streams. We evaluated our samplers against standard automated water samplers (ISCO 2900 and ISCO 6712) during the snowmelt in the Black Forest and the Alps and tested them in remote glacial catchments in Iceland, Switzerland and Kyrgyzstan. The results clearly showed that our samplers are an adequate tool for time-integrated, water level proportional water sampling at remote test sites, as they do not need batteries, are relatively inexpensive, lightweight, and compact. They are well suited for headwater streams - especially when sampling for stable isotopes - as the sampled water is perfectly protected against evaporation. Moreover, our samplers have a reduced risk of icing in cold environments, as they are installed submersed in water, whereas automated samplers (typically installed outside the stream) may get clogged due to icing of hoses. Based on this study, we find these samplers to be an adequate replacement for automated samplers when time-integrated sampling or solute load estimates are the main monitoring tasks.

  1. Multifractal detrended fluctuation analysis in examining scaling properties of the spatial patterns of soil water storage

    Directory of Open Access Journals (Sweden)

    A. Biswas

    2012-03-01

    Full Text Available Knowledge about the scaling properties of soil water storage is crucial in transferring locally measured fluctuations to larger scales and vice-versa. Studies based on remotely sensed data have shown that the variability in surface soil water has clear scaling properties (i.e., statistically self similar over a wider range of spatial scales. However, the scaling property of soil water storage to a certain depth at a field scale is not well understood. The major challenges in scaling analysis for soil water are the presence of localized trends and nonstationarities in the spatial series. The objective of this study was to characterize scaling properties of soil water storage variability through multifractal detrended fluctuation analysis (MFDFA. A field experiment was conducted in a sub-humid climate at Alvena, Saskatchewan, Canada. A north-south transect of 624-m long was established on a rolling landscape. Soil water storage was monitored weekly between 2002 and 2005 at 104 locations along the transect. The spatial scaling property of the surface 0 to 40 cm depth was characterized using the MFDFA technique for six of the soil water content series (all gravimetrically determined representing soil water storage after snowmelt, rainfall, and evapotranspiration. For the studied transect, scaling properties of soil water storage are different between drier periods and wet periods. It also appears that local controls such as site topography and texture (that dominantly control the pattern during wet states results in multiscaling property. The nonlocal controls such as evapotranspiration results in the reduction of the degree of multiscaling and improvement in the simple scaling. Therefore, the scaling property of soil water storage is a function of both soil moisture status and the spatial extent considered.

  2. Mitochondrial phylogeography of rock-dwelling cichlid fishes reveals evolutionary influence of historical lake level fluctuations of Lake Tanganyika, Africa.

    Science.gov (United States)

    Verheyen, E; Rüber, L; Snoeks, J; Meyer, A

    1996-06-29

    The East African Lakes Tanganyika, Malawi and Victoria each harbour hundreds of endemic invertebrate and vertebrate species. Inferences about the ecological and evolutionary processes responsible for the origin of these species flocks will only be possible when they are made within historical and comparative frameworks. Specifically, the relative importance of intrinsic characteristics and extrinsic factors may offer information about the processes that drive diversification and speciation in these species. We investigated the sequence variation of a segment of the mitochondrial DNA control region of 32 populations representing all four nominal species in the three genera of eretmodine cichlids from Lake Tanganyika. Based on a phylogenetic analysis of these data we attempted to evaluate the importance of major lake level fluctuations on patterns of intralacustrine speciation. The geography of genetic variation reveals a high degree of within-lake endemism among genetically well-separated lineages distributed along the inferred shore lines of three historically intermittent lake basins. Seismic data indicate that extreme lowering of water levels in the Pleistocene caused the single Lake Tanganyika basin to split into three isolated ones. The strong phylogeographic structure of the Eretmodini, and the observation that some closely related populations occur on opposite shores of the lake, agree with this geological scenario. The three-clade-three-basin phylogeographic pattern was repeated twice within this tribe of cichlids. The phylogeographic pattern of eretmodine cichlids suggests that major fluctuations in the level of the lake have been important in shaping their adaptive radiation and speciation. The mitochondrially defined clades are in conflict with the current taxonomy of the group and suggest that there has been convergent evolution in trophic morphology, particularly in the shapes of oral teeth, taxonomically the most diagnostic characters of the three genera. PMID:8693021

  3. Investment choice and perceived mating intentions regulated by external resource cues and internal fluctuation in blood glucose levels

    Science.gov (United States)

    Rao, Li-Lin; Wang, Xiao-Tian; Li, Shu

    2015-01-01

    We examined resource allocation priorities in the framework of an updated Maslow hierarchy of fundamental human needs. In Experiment 1, the participants in the food abundance priming condition viewing photos of high-calorie food allocated more money to savings than to spending. However, the participants preferred spending to savings under the condition of mating availability priming with romantic photographs. In Experiment 2, before and after drinking either water or a sugary beverage, fasting participants rated photos of a conversation between a man and a woman. Water drinking lowered the rating scores of mating intentions as well as blood glucose (BG) levels. The sugary drink buffered this decline in sexual perceptivity. Overall, the change in BG levels was positively associated with changes in the ratings of mating intentions but was not associated with other likelihood ratings. These results suggest that both external cues of food and mating resources and internal BG fluctuation regulate the cognitive priority of physiological needs vs. mate acquisition and retention. PMID:25610412

  4. Investment choice and perceived mating intentions regulated by external resource cues and internal fluctuation in blood glucose levels.

    Science.gov (United States)

    Rao, Li-Lin; Wang, Xiao-Tian; Li, Shu

    2014-01-01

    We examined resource allocation priorities in the framework of an updated Maslow hierarchy of fundamental human needs. In Experiment 1, the participants in the food abundance priming condition viewing photos of high-calorie food allocated more money to savings than to spending. However, the participants preferred spending to savings under the condition of mating availability priming with romantic photographs. In Experiment 2, before and after drinking either water or a sugary beverage, fasting participants rated photos of a conversation between a man and a woman. Water drinking lowered the rating scores of mating intentions as well as blood glucose (BG) levels. The sugary drink buffered this decline in sexual perceptivity. Overall, the change in BG levels was positively associated with changes in the ratings of mating intentions but was not associated with other likelihood ratings. These results suggest that both external cues of food and mating resources and internal BG fluctuation regulate the cognitive priority of physiological needs vs. mate acquisition and retention. PMID:25610412

  5. Statistical analysis of hydrographs and water-table fluctuation to estimate groundwater recharge

    Science.gov (United States)

    Moon, Sang-Ki; Woo, Nam C.; Lee, Kwang S.

    2004-06-01

    Using water-table monitoring data from the National Groundwater Monitoring Network in Korea, groundwater hydrographs were classified into five typical groups. Then, to estimate groundwater recharge, a modified water-table fluctuation (WTF) method was developed from the relation between the cumulative WTF and corresponding precipitation records. Applying this method to different types of hydrographs, the spatial variability of recharge in river basins was evaluated. Each estimated recharge can be considered the maximum value, and therefore, could be used as a cut-off guideline (an upper limit) for groundwater development in river basins.

  6. Quantum fluctuations and isotope effects in ab initio descriptions of water

    International Nuclear Information System (INIS)

    Isotope substitution is extensively used to investigate the microscopic behavior of hydrogen bonded systems such as liquid water. The changes in structure and stability of these systems upon isotope substitution arise entirely from the quantum mechanical nature of the nuclei. Here, we provide a fully ab initio determination of the isotope exchange free energy and fractionation ratio of hydrogen and deuterium in water treating exactly nuclear quantum effects and explicitly modeling the quantum nature of the electrons. This allows us to assess how quantum effects in water manifest as isotope effects, and unravel how the interplay between electronic exchange and correlation and nuclear quantum fluctuations determine the structure of the hydrogen bond in water

  7. Quantum fluctuations and isotope effects in ab initio descriptions of water

    CERN Document Server

    Wang, Lu; Markland, Thomas E

    2014-01-01

    Nuclear quantum effects, such as zero-point energy and tunneling, cause significant changes to the structure and dynamics of hydrogen bonded systems such as liquid water. However, due to the current inability to simulate liquid water using an exact description of its electronic structure, the interplay between nuclear and electronic quantum effects remains unclear. Here we use simulations that incorporate the quantum mechanical nature of both the nuclei and electrons to provide a fully ab initio determination of the particle quantum kinetic energies, free energy change upon exchanging hydrogen for deuterium and the isotope fractionation ratio in water. These properties, which selectively probe the quantum nature of the nuclear degrees of freedom, allow us to make direct comparison to recent experiments and elucidate how electronic exchange and correlation and nuclear quantum fluctuations determine the structure of the hydrogen bond in water.

  8. Numerical analysis of a three-phase system with a fluctuating water table

    International Nuclear Information System (INIS)

    Numerical simulations are presented of a one-dimensional, multiphase flow system that involves the redistribution of aqueous-phase liquids and nonaqueous-phase liquids (NAPLs) by a fluctuating water table. The numerical analyses were completed using an integrated-volume, finite-difference-based solution scheme of the governing multiphase conservation equations and constitutive theory. Conservation equations were solved for two components water and oil, with the assumption of a passive gas-phase. Nonlinearities introduced into the governing conservation equations through the constitutive theory were handled with a multivariable Newton-Raphson iterative scheme. The functional relationships between the phase relative permeability, the phase saturation, and phase pressures in porous media were described with a general theoretical model that includes the effects of air and oil occlusion during imbibition. Parameters required for the theoretical model were defined for two-phase systems (e.g., air- water, air-oil, and oil-water). The theoretical model assumes that wettability decreases in the following order: water, oil, air. Results from the numerical simulations are compared against measurements taken from a previous multiphase flow experiment. The experiment involved subjecting an initially water-drained, three-phase system (i.e., air-oil-water), to a fluctuating water table. The experimental objective was to quantify the entrapment of air and NAPL by phases of greater wettability under dynamic conditions. Comparison of numerical and experimental results were made for two ratios of imbibition to drainage characteristic, curve-shape parameters and two models for relative permeability in two-phase systems. A description of the numerical methods used to solve the governing conservation and constitutive equations for multiphase hysteretic conditions is given

  9. Water table fluctuation and its effects on vegetation in a semiarid environment

    Directory of Open Access Journals (Sweden)

    L. Duan

    2011-04-01

    Full Text Available A good understanding of water table fluctuation effects on vegetation is crucial for sustaining fragile hydrology and ecology of semiarid areas such as the Horqin Sandy Land (HSL in northern China, but such understanding is not well documented in literature. The objectives of this study were to examine spatio-temporal variations of water table and their effects on vegetation in a semiarid environment. A 9.71 km2 area within the HSL was chosen and well-instrumented to continuously measure hydrometeorologic parameters (e.g., water table. The area comprises of meadow lands and sandy dunes as well as transitional zones in between. In addition to those measured data, this study also used Landsat TM and MODIS imageries and meteorological data at a station near the study area. The spatio-temporal variations were examined using visual plots and contour maps, while the effects on vegetation were determined by overlaying a water table depth map with a vegetation index map derived from the MODIS imageries. The results indicated that water table was mainly dependent on local topography, localized geological settings, and human activities (e.g., reclamation. At annual and monthly scales, water table was mainly a function of precipitation and potential evapotranspiration. A region within the study area where depth to water table was smaller tended to have better (i.e., more dense and productive vegetation cover. Further, the results revealed that water table fluctuation was more sensitive for vegetations in the meadow lands than in the transitional zones, but it was least sensitive for vegetations in the sandy dunes.

  10. Kinetic parameters and intraindividual fluctuations of ochratoxin A plasma levels in humans

    International Nuclear Information System (INIS)

    The mycotoxin ochratoxin A (OTA) is a rodent carcinogen produced by species of the ubiquitous fungal genera Aspergillus and Penicillium. OTA is found in a variety of food items and as a consequence is also found in human plasma (average concentrations found in this study: 0.1-1 ng OTA/ml plasma). To improve the scientific basis for cancer risk assessment the toxicokinetic profile of OTA was studied in one human volunteer following ingestion of 395 ng 3H-labeled OTA (3.8 ?Ci). A two-compartment open model consisting of a central compartment was found to best describe the in vivo data. This two-compartment model consisted of a fast elimination and distribution phase (T1/2 about 20 h) followed by a slow elimination phase (renal clearance about 0.11 ml/min.) and a calculated plasma half-life of 35.55 days. This half-life was approximately eight times longer than that determined previously in rats. In addition, the intraindividual fluctuation of OTA plasma levels was investigated in eight individuals over a period of 2 months. The concentrations determined ranged between 0.2 and 0.9 ng OTA/ml plasma. The plasma levels in some individuals remained nearly constant over time, while others varied considerably (e.g. increase of 0.4 ng/ml within 3 days, decrease of 0.3 ng/ml within 5 days) during the observation period. This intraindividual fluctuation in OTA plasma levels, which may represent differences in OTA exposure and/or metabolism, as well as the losure and/or metabolism, as well as the large difference in plasma half-life in humans compared to rats must be taken into consideration when the results of rat cancer study data are extrapolated to humans for risk assessment purposes. (orig.)

  11. Water levels in continuously monitored wells in the Yucca Mountain Area, Nevada, 1989

    International Nuclear Information System (INIS)

    Water levels have been monitored hourly in 16 wells representing 24 intervals in the Yucca Mountain area, Nevada. Water levels were monitored using pressure transducers and were recorded by data loggers. The pressure transducers were periodically calibrated by raising and lowering them in the wells. The water levels were normally measured at approximately the same time that the transducers were calibrated. Where the transducer output appeared reasonable, it was converted to water levels using the calibrations and manual water-level measurements. The amount of transducer output that was converted to water levels ranged from zero for one interval to 100 percent for one interval. Fifteen of the wells were completed in Tertiary volcanic rocks and one well was completed in Paleozoic carbonate rocks. Each well monitored from one to four depth intervals. Water-level fluctuation caused by barometric pressure changes and earth tides were observed. Transducer output is presented in graphic form and, where appropriate, water-level altitude is presented in graphical and tabular form

  12. Thermal striping temperature fluctuation analysis using the algebraic stress turbulence model in water and sodium

    International Nuclear Information System (INIS)

    A three-dimensional temperature fluctuation analysis was carried out using a general-purpose multidimensional thermohydraulic analysis code for a 1 : 2 scale model water experiment and a 1 : 1 scale model sodium experiment simulating thermal striping phenomena. The code was incorporated with an algebraic stress turbulence model (ASM) and an adaptive control system based on the fuzzy theory to control time step sizes. Calculational results under the test conditions of various flow velocity ratios showed good agreement with the measured intensity distribution and maximum value of the temperature fluctuations. From the analysis, it was concluded that (1) the ASM is applicable to the intensity evaluation of the temperature fluctuations related to the thermal striping phenomena, (2) a combined approach of the ASM and the higher-order accurate schemes such as the quadratic upstream interpolation for convective kinematics (QUICK) and QUICK with the filtering remedy and methodology (FRAM) is recommended to analyze overall turbulent flow and temperature fields in engineering applications, and (3) the adaptive time step size control system is practical in reducing computing efforts. (author)

  13. Analysis of water-level data in the Yucca Mountain area, Nevada, 1985--95

    International Nuclear Information System (INIS)

    From 1985 through 1995, a water-level network that consists of 28 wells for monitoring 36 depth intervals has been maintained in the Yucca Mountain area. The network includes wells that were measured manually, approximately monthly, and/or measured hourly with a transducer/data logger system. Manual water-level measurements were made with either calibrated steel tapes or single or multiconductor-cable units. All wells monitor water levels in Tertiary volcanic rocks, except one that monitors water levels in Paleozoic carbonate rocks. Annual mean water-level altitudes for all wells for the period 1985-95 ranged from 727.93 to 1,034.60 meters. The maximum range in water-level change between monthly measurements and/or monthly mean values was 12.22 meters in well USW H-3 lower interval, and the minimum range was 0.31 meter in wells UE-25 b-1 upper interval, and J-11. In 31 of the 36 depth intervals monitored, the range of water-level change was less than 1 meter. The range of standard deviation of all depth interval measurements for all wells that were monitored was 0.053 to 3.098 meters. No seasonal water-level trends were detected in any of the wells, and regional ground-water withdrawals did not appear to cause water-level changes. Most annual water-level fluctuations can be attributed to barometric and Earth-tide changes. Regional earthquakes, which occurred on June 28--29, 1992, might have simultaneously affected the water level in seven wells. Periods of rising and vel in seven wells. Periods of rising and declining water levels were observed in most wells. However, 11 years of record were not sufficient to determine if these periods were cyclic. Because a goal of monitoring water levels at Yucca Mountain is to determine if there are water-level trends that could affect the potential repository, observed water-level changes over the period of this report may not be representative of the overall long-term trends in water levels

  14. Using GPS Interferometric Reflectometry to estimate soil moisture and vegetation water content fluctuations

    Science.gov (United States)

    Chew, C. C.; Small, E. E.; Larson, K. M.; Braun, J. J.; Shreve, C. M.

    2010-12-01

    High-precision GPS receivers can be used to estimate fluctuations in near surface soil moisture, snow and vegetation water content. This approach, referred to as GPS-Interferometric Reflectometry (GPS-IR), relates precise changes in the geometry of reflected GPS signals to observe soil moisture and snow while simultaneously using signal attenuation and diffuse scattering to infer changes in vegetative state. Previous remote sensing research has shown that microwave signals (e.g., L-band) are optimal for measuring hydrologic variables, such as soil moisture, and because GPS satellites transmit similar signals, they can be useful for sensing water in the environment. In addition, standard GPS antenna configurations that are used in NSF's Plate Boundary Observatory network yield sensing footprints of ~1000 m2. Given this sensitivity, hundreds of GPS receivers that exist in the U.S. could be used to provide near-real time estimates of soil moisture and vegetation water content for satellite validation, drought monitoring and related studies. A significant obstacle to using L-band (or similar) signals for remote sensing is differentiating the effects of soil moisture and vegetation on the retrieval of hydrologic variables. This same challenge exists when using GPS-IR data. We have established nine research sites with identical GPS and hydrologic infrastructure to study this problem. These sites span a wide range of soil, vegetation, and climate types. In addition to daily GPS and hourly soil moisture data, we have collected weekly vegetation water content samples at all sites. Our data demonstrate that soil moisture fluctuations can be estimated from GPS-IR records when vegetation water content is low (soil moisture and vegetation signals and quantifying errors in our retrieval algorithm.

  15. Fluctuations of sea water temperature based on nannofloral changes during the Middle to Late Miocene, Adana Basin, Turkey

    OpenAIRE

    SINACI, Manolya

    2013-01-01

    Some nannoplankton species are sensitive to water temperatures. While Coccolithus pelagicus and Reticulofenestra gelida indicate cooler water conditions, the genera Discoaster and Sphenolithus and Calcidiscus leptoporus are indicative of warmer water environments. This paper focuses on relative fluctuation of sea water temperatures during the Middle and Late Miocene, emphasised by cold and warm nannofossil changes in abundance in 2 wells. At the A-1 well in the Middle Miocene, the total abund...

  16. Relationship between fluctuations in glucose levels measured by continuous glucose monitoring and vascular endothelial dysfunction in type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Torimoto Keiichi

    2013-01-01

    Full Text Available Abstract Background Fluctuations in blood glucose level cause endothelial dysfunction and play a critical role in onset and/or progression of atherosclerosis. We hypothesized that fluctuation in blood glucose levels correlate with vascular endothelial dysfunction and that this relationship can be assessed using common bedside medical devices. Methods Fluctuations in blood glucose levels were measured over 24?hours by continuous glucose monitoring (CGM on admission day 2 in 57 patients with type 2 diabetes mellitus. The reactive hyperemia index (RHI, an index of vascular endothelial function, was measured using peripheral arterial tonometry (EndoPAT on admission day 3. Results The natural logarithmic-scaled RHI (L_RHI correlated with SD (r=?0.504; PPP=0.001 and percentage of time ?200?mg/dl (r=?0.292; P=0.028. In 12 patients with hypoglycemia, L_RHI also correlated with the percentage of time at hypoglycemia (r=?0.589; P=0.044. L_RHI did not correlate with HbA1c or fasting plasma glucose levels. Furthermore, L_RHI did not correlate with LDL cholesterol, HDL cholesterol, and triglyceride levels or with systolic and diastolic blood pressures. Finally, multivariate analysis identified MAGE as the only significant determinant of L_RHI. Conclusions Fluctuations in blood glucose levels play a significant role in vascular endothelial dysfunction in type 2 diabetes. Trial registration UMIN000007581

  17. Sea-level fluctuations show Ocean Circulation controls Atlantic Multidecadal Variability

    Science.gov (United States)

    McCarthy, Gerard; Haigh, Ivan; Hirschi, Joel; Grist, Jeremy; Smeed, David

    2015-04-01

    We present observational evidence that ocean circulation controls the decadal evolution of heat content and consequently sea-surface temperatures (SST) in the North Atlantic. One of the most prominent modes of Atlantic variability is the Atlantic multidecadal oscillation (AMO) observed in SSTs. Positive (negative) phases of the AMO are associated with warmer (cooler) SSTs. Positive phases of the AMO have been linked with decadal climate fluctuations including increased summer precipitation in Europe; increased northern hemisphere land temperatures, fewer droughts in the Sahel region of Africa and increased Atlantic hurricane activity. It is widely believed that the Atlantic circulation controls the phases of the AMO by controlling the decadal changes in heat content in the North Atlantic. However, due to the lack of ocean circulation observations, this link has not been previously proven. We present a new interpretation of the sea-level gradient along to the east coast of the United States to derive a measure of ocean circulation spanning decadal timescales. We use this to estimate heat content changes that we validate against direct estimates of heat content. We use the longevity of the tide gauge record to show that circulation, as interpreted in sea-level gradient changes, drives the major transitions in the AMO since the 1920's. We show that the North Atlantic Oscillation is highly correlated with this sea-level gradient, indicating that the atmosphere drives the circulation changes. The circulation changes are essentially integrated by the ocean in the form of ocean heat content and returned to the atmosphere as the AMO. An additional consequence of our interpretation is that recently reported accelerations in sea-level rise along the US east coast are consistent with a declining AMO that has been predicted by a number of authors.

  18. Drinking Water Maximum Contaminant Levels (MCLs)

    U.S. Environmental Protection Agency — National Primary Drinking Water Regulations (NPDWRs or primary standards) are legally enforceable standards that apply to public water systems. Primary standards...

  19. A Convective Model Conm That Simulates Solute Redistribution Caused by Water Table Fluctuations

    Directory of Open Access Journals (Sweden)

    Cesáreo Landeros-Sánchez

    2012-11-01

    Full Text Available A study of the solute redistribution caused by water-table fluctuations in experimental packed columns of fine sand and a sandy clay loam soil using potassium chloride as a non-reactive tracer is modelled. With the water table initially at the soil surface, the redistribution of surface applied chloride down the profile was measured after the water table was lowered, then after it was raised again to the soil surface, and then after it was again lowered. In each case, sufficient time was allowed before measurements of chloride were made for the soil-water profile in the column to approach equilibrium conditions with the water table. A simple convection model (CONM was developed and used to simulate the chloride redistribution. This was compared with the LEACHM model of Wagenet and Hutson based on the convection-dispersion equation, and the physical basis of each critically discussed. It was found that the experimental results in general agreed better with simulated results using CONM than with those using LEACHM. It was concluded that the chloride movement observed in the experimental columns was dominantly convective. The application of this work to optimise fertiliser requirements when subirrigation-drainage systems are employed is discussed.

  20. Fluctuation of TeV to EeV Energy Muons and Induced Muon Showers in Water

    OpenAIRE

    Okumura, Y.; Takahashi, N.; Misaki, A.

    2010-01-01

    By using the integral method in the muon propagation through water, we calculate the range fluctuation of high and ultra high energy muons. Many authors divide all radiative processes into two parts, namely, the continuous part and radiative part in their Monte Carlo simulation in order to consider the fluctuation in the both ranges and energies of the muons, while we treat all stochastic processes as exactly as possible, without the introduction of the continuous parts in a...

  1. A Simple Water Balance Approach to Monitor Lake Water Level Changes: Validation using TOPEX/Poseidon and Jason Altimetry Data

    Science.gov (United States)

    Velpuri, N.; Senay, G. B.; Alemu, H.; Asante, K. O.

    2008-12-01

    A simple water balance approach is adapted to monitor water resources in semi-arid region of east Africa by integrating coarse and dynamic datasets such as rainfall with fine and static elevation datasets. The model takes in Tropical Rainfall Measuring Mission (TRMM) rainfall data, modeled runoff and reference evapotranspiration (ET) data to monitor changes in lake water heights. Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM) was used to delineate lake Turkana watershed. A simple water balance modeling approach was applied on Turkana basin to estimate lake water level heights for ten years (1997- 2008) and the results were compared with TOPEX/Poseidon and Jason satellite altimeter data. It was observed that simple water balance approach could capture the trend and seasonal variations of lake water fluctuations as measured by the satellite. The El Nino year of 1998 and the following consecutive dry years until 2002 are captured well on both. A mean deviation up to 30 cm of lake water height was found when compared to the satellite measurements. The satellite measurements made since 2004 showed that the lake water height gradually reduced, whereas simulations made using the water balance model showed an increasing trend. This could be reasoned by the fact that, on the Omo river, which contributes to over 80% of the lake inflows, a dam was commissioned in 2004. Knowledge of such processes occurring upstream or downstream is often required while analyzing satellite altimetry data to avoid misinterpretation. Although the absolute accuracy is low, the advantage of the simple water balance method lies in its ability to: (i) capture the trend and seasonal variations of water level fluctuations of small to large lakes around the world; (ii) when coupled with ground measurements or satellite altimetry data for lake water heights, the simple water balance method can identify the presence and absence of upstream and downstream processes; (iii) since water balance approach gives water level variations assuming no flow regulating mechanisms, the simulations can be used to study the impact of climate change on the hydrology of the basin.

  2. Development of heater-and-thermocouple-type water level sensor

    International Nuclear Information System (INIS)

    In the Fukushima-Daiichi Nuclear Power Plant Accident, the measurements of water level in pressure vessel and spent fuel pool was impossible due to station blackout, and it resulted in difficulty for countermeasures against the accidents and for understanding of the situations of reactor core after accidents. Therefore, we started to develop a new water level sensor for spent fuel pool with high reliability, which works with low power voltage. This report describes reviews of conventional water level sensor and design and production of new water level sensor. After production of the sensor, performance tests were performed at the water temperature between room temperature and 95degC, and the it was confirmed that the sensor is able to measure water level with the accuracy of ±20mm. As the results, a perspective to use the new water level sensor as water level gauge for spent fuel pool and reactor vessels after severe accident is acquired. (author)

  3. Cyclic water level oscillations of the KaraBogazGol-Caspian Sea system

    Science.gov (United States)

    Giralt, S.; Julià, R.; Leroy, S.; Gasse, F.

    2003-07-01

    The KaraBogazGol (KBG) water level oscillations were reconstructed in the last 200 years using the geochemical evolution of the uppermost meter of its sedimentary infill. High-resolution studies of the mineralogical composition of the KBG sediments show alternating periods of high concentration brines followed by periods of more dilute waters. The relative water level reconstruction was based on statistical models (factor analysis (FA), correspondence analyses (CA) and detrended correspondence analyses (DCA)) whilst the chronological framework was established using the 210Pb technique. This reconstruction was compared with the instrumental water level record of the Caspian Sea, showing a high degree of correlation ( r2=0.83). The agreement between the reconstructed and the measured water level oscillations of the Caspian Sea indicates that environmental changes can be reconstructed from closed lakes provided that an accurate chronological control of sedimentary processes is available. The water level reconstruction shows that the Caspian Sea water level fluctuations follow a cyclical pattern rather than an 'erratic' one, as has been suggested in the literature. Two main periodicities of 62.5 and 38.46 years have been found.

  4. Distinct role of hydration water in protein misfolding and aggregation revealed by fluctuating thermodynamics analysis.

    Science.gov (United States)

    Chong, Song-Ho; Ham, Sihyun

    2015-04-21

    Protein aggregation in aqueous cellular environments is linked to diverse human diseases. Protein aggregation proceeds through a multistep process initiated by conformational transitions, called protein misfolding, of monomer species toward aggregation-prone structures. Various forms of aggregate species are generated through the association of misfolded monomers including soluble oligomers and amyloid fibrils. Elucidating the molecular mechanisms and driving forces involved in the misfolding and subsequent association has been a central issue for understanding and preventing protein aggregation diseases such as Alzheimer's, Parkinson's, and type II diabetes. In this Account, we provide a thermodynamic perspective of the misfolding and aggregation of the amyloid-beta (A?) protein implicated in Alzheimer's disease through the application of fluctuating thermodynamics. This approach "dissects" the conventional thermodynamic characterization of the end states into the one of the fluctuating processes connecting them, and enables one to analyze variations in the thermodynamic functions that occur during the course of protein conformational changes. The central quantity in this approach is the solvent-averaged effective energy, f = Eu + Gsolv, comprising the protein potential energy (Eu) and the solvation free energy (Gsolv), whose time variation reflects the protein dynamics on the free energy landscape. Protein configurational entropy is quantified by the magnitude of fluctuations in f. We find that misfolding of the A? monomer when released from a membrane environment to an aqueous phase is driven by favorable changes in protein potential energy and configurational entropy, but it is also accompanied by an unfavorable increase in solvation free energy. The subsequent dimerization of the misfolded A? monomers occurs in two steps. The first step, where two widely separated monomers come into contact distance, is driven by water-mediated attraction, that is, by a decrease in solvation free energy, harnessing the monomer solvation free energy earned during the misfolding. The second step, where a compact dimer structure is formed, is driven by direct protein-protein interactions, but again it is accompanied by an increase in solvation free energy. The increased solvation free energy of the dimer will function as the driving force to recruit another A? protein in the approach stage of subsequent oligomerizations. The fluctuating thermodynamics analysis of the misfolding and dimerization of the A? protein indicates that the interaction of the protein with surrounding water plays a critical role in protein aggregation. Such a water-centric perspective is further corroborated by demonstrating that, for a large number of A? mutants and mutants of other protein systems, the change in the experimental aggregation propensity upon mutation has a significant correlation with the protein solvation free energy change. We also find striking discrimination between the positively and negatively charged residues on the protein surface by surrounding water molecules, which is shown to play a crucial role in determining the protein aggregation propensity. We argue that the protein total charge dictates such striking behavior of the surrounding water molecules. Our results provide new insights for understanding and predicting the protein aggregation propensity, thereby offering novel design principles for producing aggregation-resistant proteins for biotherapeutics. PMID:25844814

  5. Modelling wetland bird response to water level changes in the Lake Ontario - St. Lawrence River hydrosystem.

    Science.gov (United States)

    Desgranges, Jean-Luc; Ingram, Joel; Drolet, Bruno; Morin, Jean; Savage, Caroline; Borcard, Daniel

    2006-02-01

    Lake Ontario and St. Lawrence River (LOSL) wetland bird abundance and diversity are greatly influenced by lake and river hydrology. Our study used an interdisciplinary ecosystem approach, blending avian and plant ecology, ecohydraulic, statistical ecology and modelling to evaluate potential impacts of water level fluctuations on indicator species representative of the wetland breeding bird assemblages in the entire LOSL freshwater system. Multi-year (2000-2003) bird surveys captured bird distribution and density in wetland habitats under varying degrees of water inandation, depth and fluctuation. Analyses revealed strong associations between estimated breeding pair densities and plant communities, water depth, and degree of water level fluctuation during the breeding season for a suite of wetland bird species using marsh, wet meadow, shrub swamp and treed swamp habitats. These quantitative associations were used to develop wetland bird performance indicators for use in a LOSL water regulation review study. Several bird species also nest at or near the water surface and are thus vulnerable to nest flooding or stranding. Changes to the seasonal hydrology of Lake Ontario and St. Lawrence River that result in an increased frequency or magnitude of these nest failure events may have a significant impact on regional population sustainability. Long term nest record databases were analyzed to create nesting flooding and stranding probability equations based on water level increases and decreases during the breeding season. These species-specific nesting relationships were incorporated into a reproduction index. Many breeding bird species were strongly associated with specific wetland plant communities. Predicted habitat suitability, as measured by estimated breeding pair density, can also change significantly within a specific wetland plant community based solely on changes in water depth during the breeding season. Three indicator species, Black Tern, Least Bittern and Virginia Rail were selected as key environmental performance indicators for alternate regulation plan comparisons. Water regulation criteria should be such that the long term diversity and abundance of wetland plant communities and frequency of spring flooding in marsh habitats during breeding are not reduced. Magnitude and frequency of water level change during the nesting season (May-July) can also adversely impact reproductive success of many wetland bird species. As such, regulation criteria that increase the seasonal magnitude and frequency of water level change may be detrimental to the long term viability of certain regional breeding bird populations. PMID:16518674

  6. High-frequency volume and boundary acoustic backscatter fluctuations in shallow water.

    Science.gov (United States)

    Gallaudet, Timothy C; de Moustier, Christian P

    2003-08-01

    Volume and boundary acoustic backscatter envelope fluctuations are characterized from data collected by the Toroidal Volume Search Sonar (TVSS), a 68 kHz cylindrical array capable of 360 degrees multibeam imaging in the vertical plane perpendicular to its axis. The data are processed to form acoustic backscatter images of the seafloor, sea surface, and horizontal and vertical planes in the volume, which are used to attribute nonhomogeneous spatial distributions of zooplankton, fish, bubbles and bubble clouds, and multiple boundary interactions to the observed backscatter amplitude statistics. Three component Rayleigh mixture probability distribution functions (PDFs) provided the best fit to the empirical distribution functions of seafloor acoustic backscatter. Sea surface and near-surface volume acoustic backscatter PDFs are better described by Rayleigh mixture or log-normal distributions, with the high density portion of the distributions arising from boundary reverberation, and the tails arising from nonhomogeneously distributed scatterers such as bubbles, fish, and zooplankton. PDF fits to the volume and near-surface acoustic backscatter data are poor compared to PDF fits to the boundary backscatter, suggesting that these data may be better described by mixture distributions with component densities from different parametric families. For active sonar target detection, the results demonstrate that threshold detectors which assume Rayleigh distributed envelope fluctuations will experience significantly higher false alarm rates in shallow water environments which are influenced by near-surface microbubbles, aggregations of zooplankton and fish, and boundary reverberation. PMID:12942954

  7. Lowest Landau level scaling of the fluctuation conductivity for RFeAsO (R=Nd,Pr,Sm) superconductors

    International Nuclear Information System (INIS)

    The fluctuation conductivity under magnetic fields is studied in RFeAsO (R=Nd,Pr,Sm) superconductors reported in literatures within the lowest Landau level (LLL) scaling approach. The mean filed critical temperature Tc(H) is determined by the crossing point technique. With the determined values of Tc(H), the fluctuation conductivity is scaled within both three-dimensional (3D) and two-dimensional (2D) LLL approach. For all the samples studied, the 3D-LLL scaling is found but in a relatively small temperature interval around Tc(H), while 2D-LLL scaling is observed in all other temperature region. These results suggest a 3D-2D crossover of the fluctuation conductivity in RFeAsO superconductors.

  8. Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap system

    Science.gov (United States)

    Cochrane, T. A.; Arias, M. E.; Piman, T.

    2014-11-01

    The rapid rate of water infrastructure development in the Mekong Basin is a cause for concern due to its potential impact on fisheries and downstream natural ecosystems. In this paper, we analyze the historical water levels of the Mekong River and Tonle Sap system by comparing pre- and post-1991 daily observations from six stations along the Mekong mainstream from Chiang Saen (northern Thailand), to Stung Treng (Cambodia), and the Prek Kdam station on the Tonle Sap River. Observed alterations in water level patterns along the Mekong are linked to temporal and spatial trends in water infrastructure development from 1960 to 2010. We argue that variations in historical climatic factors are important, but they are not the main cause of observed changes in key hydrological indicators related to ecosystem productivity. Our analysis shows that the development of mainstream dams in the upper Mekong Basin in the post-1991 period may have resulted in a modest increase of 30-day minimum levels (+17%), but significant increases in fall rates (+42%) and the number of water level fluctuations (+75%) observed in Chiang Saen. This effect diminishes downstream until it becomes negligible at Mukdahan (northeast Thailand), which represents a drainage area of over 50% of the total Mekong Basin. Further downstream at Pakse (southern Laos), alterations to the number of fluctuations and rise rate became strongly significant after 1991. The observed alterations slowly decrease downstream, but modified rise rates, fall rates, and dry season water levels were still quantifiable and significant as far as Prek Kdam. This paper provides the first set of evidence of hydrological alterations in the Mekong beyond the Chinese dam cascade in the upper Mekong. Given the evident alterations at Pakse and downstream, post-1991 changes could also be directly attributed to water infrastructure development in the Chi and Mun basins of Thailand. A reduction of 23 and 11% in the water raising and falling rates respectively at Prek Kdam provides evidence of a diminished Tonle Sap flood pulse in the post-1991 period. Given the observed water level alterations from 1991 to 2010 as a result of water infrastructure development, we can extrapolate that future development in the mainstream and the key transboundary Srepok, Sesan, and Sekong sub-basins will have an even greater effect on the Tonle Sap flood regime, the lower Mekong floodplain, and the delta.

  9. Fluctuating micro-heterogeneity in water–tert-butyl alcohol mixtures and lambda-type divergence of the mean cluster size with phase transition-like multiple anomalies

    International Nuclear Information System (INIS)

    Water–tert-butyl alcohol (TBA) binary mixture exhibits a large number of thermodynamic and dynamic anomalies. These anomalies are observed at surprisingly low TBA mole fraction, with xTBA ? 0.03–0.07. We demonstrate here that the origin of the anomalies lies in the local structural changes that occur due to self-aggregation of TBA molecules. We observe a percolation transition of the TBA molecules at xTBA ? 0.05. We note that “islands” of TBA clusters form even below this mole fraction, while a large spanning cluster emerges above that mole fraction. At this percolation threshold, we observe a lambda-type divergence in the fluctuation of the size of the largest TBA cluster, reminiscent of a critical point. Alongside, the structure of water is also perturbed, albeit weakly, by the aggregation of TBA molecules. There is a monotonic decrease in the tetrahedral order parameter of water, while the dipole moment correlation shows a weak nonlinearity. Interestingly, water molecules themselves exhibit a reverse percolation transition at higher TBA concentration, xTBA ? 0.45, where large spanning water clusters now break-up into small clusters. This is accompanied by significant divergence of the fluctuations in the size of largest water cluster. This second transition gives rise to another set of anomalies around. Both the percolation transitions can be regarded as manifestations of Janus effect at small molecular level

  10. Fluctuating micro-heterogeneity in water–tert-butyl alcohol mixtures and lambda-type divergence of the mean cluster size with phase transition-like multiple anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Saikat; Furtado, Jonathan; Bagchi, Biman, E-mail: bbagchi@sscu.iisc.ernet.in [SSCU, Indian Institute of Science, Bangalore 560012 (India)

    2014-05-21

    Water–tert-butyl alcohol (TBA) binary mixture exhibits a large number of thermodynamic and dynamic anomalies. These anomalies are observed at surprisingly low TBA mole fraction, with x{sub TBA} ? 0.03–0.07. We demonstrate here that the origin of the anomalies lies in the local structural changes that occur due to self-aggregation of TBA molecules. We observe a percolation transition of the TBA molecules at x{sub TBA} ? 0.05. We note that “islands” of TBA clusters form even below this mole fraction, while a large spanning cluster emerges above that mole fraction. At this percolation threshold, we observe a lambda-type divergence in the fluctuation of the size of the largest TBA cluster, reminiscent of a critical point. Alongside, the structure of water is also perturbed, albeit weakly, by the aggregation of TBA molecules. There is a monotonic decrease in the tetrahedral order parameter of water, while the dipole moment correlation shows a weak nonlinearity. Interestingly, water molecules themselves exhibit a reverse percolation transition at higher TBA concentration, x{sub TBA} ? 0.45, where large spanning water clusters now break-up into small clusters. This is accompanied by significant divergence of the fluctuations in the size of largest water cluster. This second transition gives rise to another set of anomalies around. Both the percolation transitions can be regarded as manifestations of Janus effect at small molecular level.

  11. Impact of scaled-down on dissolved oxygen fluctuations at different levels of the lipase synthesis pathway of Yarrowia lipolytica

    Directory of Open Access Journals (Sweden)

    Delvigne, F.

    2010-01-01

    Full Text Available The impact of the fluctuations in dissolved oxygen tension (DOT on the lipase production by Yarrowia lipolytica has been investigated in a scale-down reactor (SDR. This bioreactor comprises a 20 l agitated vessel with an automatic valve controlling the opening and closure of the air flow line. This kind of scale-down apparatus is used in order to generate DOT gradients encountered in large-scale, while maintaining the other environmental conditions constant. The impact of DOT fluctuations has been estimated at three levels of the lipase synthesis machinery: lipase gene expression, lipase translation, lipase excretion to the extracellular medium. Among these levels, the performance of lipase production under oscillating DOT was significantly affected at the lipase gene expression level.

  12. Development of reactor water level sensor for extreme conditions

    International Nuclear Information System (INIS)

    In the Fukushima accident, measurement failure of water level was one of the most important factors which caused serious situation. The differential pressure type water level indicators are widely used in various place of nuclear power plant but after the accident of TMI-2, the need of other reliable method has been required. The BICOTH type and the TRICOTH type water level indicator for light water power reactors had been developed for in-pile water level indicator but currently those are not adopted to nuclear power plant. In this study, the development of new type water level indicator composed of thermocouple and heater is described. Demonstration test and characteristic evaluation of the water level indicator were performed and we had obtained satisfactory results. (author)

  13. Water levels in the Yucca Mountain area, Nevada, 1993

    International Nuclear Information System (INIS)

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1993. Seventeen wells were monitored periodically, generally on a monthly basis, and 11 wells representing 18 intervals were monitored hourly. All wells monitor water levels in Tertiary volcanic rocks, except one that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes and pressure transducers; steel-tape measurements were corrected for mechanical stretch, thermal expansion, and borehole deviation to obtain precise water-level altitudes. Water-level altitudes in the Tertiary volcanic rocks ranged from about 728 meters above sea level east of Yucca Mountain to about 1,034 meters above sea level north of Yucca Mountain. Water-level altitudes in the well monitoring the Paleozoic carbonate rocks varied between 752 and 753 meters above sea level during 1993. Water levels were an average of about 0.04 meter lower than 1992 water levels. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  14. Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap System

    Directory of Open Access Journals (Sweden)

    T. A. Cochrane

    2014-04-01

    Full Text Available The rapid rate of water infrastructure development in the Mekong basin is a cause for concern due to its potential impact on fisheries and downstream natural ecosystems. In this paper we analyse the historical water levels of the Mekong River and Tonle Sap system by comparing pre and post 1991 daily observations from six stations along the Mekong mainstream from Chiang Sean (northern Laos, to Stung Treng (Cambodia, and the Prek Kdam station on the Tonle Sap River. Observed alterations in water level patterns along the Mekong are linked to temporal and spatial trends in water infrastructure development from 1960 to 2010. We argue that variations in historical climatic factors are important, but they are not the main cause of observed changes in key hydrological indicators related to ecosystem productivity. Our analysis shows that the development of mainstream dams in the upper Mekong basin in the post-1991 period have resulted in a significant increase of 7 day minimum (+91.6%, fall rates (+42%, and the number of water level fluctuations (+75 observed in Chiang Sean. This effect diminishes downstream until it becomes negligible at Mukdahan (northeast Thailand, which represents a drainage area of over 50% of the total Mekong Basin. Further downstream at Pakse (southern Laos, alterations to the number of fluctuations and rise rate became strongly significant after 1991. The observed alterations slowly decrease downstream, but modified rise rates, fall rates, and dry season water levels were still quantifiable and significant as far as Prek Kdam. This paper provides the first set of evidence of hydrological alterations in the Mekong beyond the Chinese dam cascade in the upper Mekong. Given the evident alterations with no precedence at Pakse and downstream, post-1991 changes can also be directly attributed to water infrastructure development in the Chi and Mun basins of Thailand. A reduction of 23 and 11% in the water raising and fall rates respectively at Prek Kdam provides evidence of a diminished Tonle Sap flood pulse in the post-1991 period. Given the observed water level alterations from 1991 to 2010 as a result of water infrastructure development, we can extrapolate that future development in the mainstream and the key transboundary Srepok, Sesan and Sekong subbasins will have an even greater effect on the Tonle Sap flood regime, the lower Mekong floodplain, and the delta.

  15. Observing plants dealing with soil water stress: Daily soil moisture fluctuations derived from polymer tensiometers

    Science.gov (United States)

    van der Ploeg, Martine; de Rooij, Gerrit

    2014-05-01

    Periods of soil water deficit often occur within a plant's life cycle, even in temperate deciduous and rain forests (Wilson et al. 2001, Grace 1999). Various experiments have shown that roots are able to sense the distribution of water in the soil, and produce signals that trigger changes in leaf expansion rate and stomatal conductance (Blackman and Davies 1985, Gollan et al. 1986, Gowing et al. 1990 Davies and Zhang 1991, Mansfield and De Silva 1994, Sadras and Milroy 1996). Partitioning of water and air in the soil, solute distribution in soil water, water flow through the soil, and water availability for plants can be determined according to the distribution of the soil water potential (e.g. Schröder et al. 2013, Kool et al. 2014). Understanding plant water uptake under dry conditions has been compromised by hydrological instrumentation with low accuracy in dry soils due to signal attenuation, or a compromised measurement range (Whalley et al. 2013). Development of polymer tensiometers makes it possible to study the soil water potential over a range meaningful for studying plant responses to water stress (Bakker et al. 2007, Van der Ploeg et al. 2008, 2010). Polymer tensiometer data obtained from a lysimeter experiment (Van der Ploeg et al. 2008) were used to analyse day-night fluctuations of soil moisture in the vicinity of maize roots. To do so, three polymer tensiometers placed in the middle of the lysimeter from a control, dry and very dry treatment (one lysimeter per treatment) were used to calculate water content changes over 12 hours. These 12 hours corresponded with the operation of the growing light. Soil water potential measurements in the hour before the growing light was turned on or off were averaged. The averaged value was used as input for the van Genuchten (1980) model. Parameters for the model were obtained from laboratory determination of water retention, with a separate model parameterization for each lysimeter setup. Results show daily fluctuations in water content changes, with both root water uptake and root water excretion. The magnitude of the water content change was in the same order for all treatments, thus suggesting compensatory uptake. References Bakker G, Van der Ploeg MJ, de Rooij GH, Hoogendam CW, Gooren HPA, Huiskes C, Koopal LK and Kruidhof H. New polymer tensiometers: Measuring matric pressures down to the wilting point. Vadose Zone J. 6: 196-202, 2007. Blackman PG and Davies WJ. Root to shoot communication in maize plants of the effects of soil drying. J. Exp. Bot. 36: 39-48, 1985. Davies WJ and Zhang J. Root signals and the regulation of growth and development of plants in drying soil. Annu. Rev. Plant Physiol. Plant Mol. Biol. 42: 55-76, 1991. Gollan T, Passioura JB and Munns R. Soil water status affects the stomatal conductance of fully turgid wheat and sunflower leafs. Aust. J. Plant Physiol. 13: 459-464, 1986. Gowing DJG, Davies WJ and Jones HG. A Positive Root-sourced Signal as an Indicator of Soil Drying in Apple, Malus x domestica Borkh. J. Exp. Bot. 41: 1535-1540, 1990. Grace J. Environmental controls of gas exchange in tropical rain forests. In: Press, M.C, J.D. Scholes and M.G. Barker (ed.). Physiological plant ecology: the 39th Symposium of the British Ecological Society. Blackwell Science, United Kingdom, 1999. Kool D, Agam N, Lazarovitch N, Heitman JL, Sauer TJ, Ben-Gal A. A review of approaches for evapotranspiration partitioning. Agricultural and Forest Meteorology 184: 56- 70, 2014. Mansfield TA and De Silva DLR. Sensory systems in the roots of plants and their role in controlling stomatal function in the leaves. Physiol. Chem. Phys. & Med. 26: 89-99, 1994. Sadras VO and Milroy SP. Soil-water thresholds for the responses of leaf expansion and gas exchange: a review. Field Crops Res. 47: 253-266, 1996. Schröder N, Lazarovitch N, Vanderborcht J, Vereecken H, Javaux M. Linking transpiration reduction to rhizosphere salinity using a 3D coupled soil-plant model. Plant Soil 2013, doi: 10.1007/s11104-013-1990-8 Van der Ploeg MJ, Gooren HPA, Bakker G and de Rooij GH.

  16. Water level influences on body condition of Geophagus brasiliensis (Perciformes: Cichlidae in a Brazilian oligotrophic reservoir

    Directory of Open Access Journals (Sweden)

    Alejandra Filippo Gonzalez Neves dos Santos

    2004-09-01

    Full Text Available Effects of water level fluctuations on body condition of Geophagus brasiliensis were studied in a 30 km² Brazilian oligotrophic reservoir. Physiological condition (K and gonadosomatic index (GSI were compared according to water level (low and high. Females' best conditions were associated to higher resources availability during high water, since gonad development did not change between low and high water. Males' condition did not change between water levels, while the highest gonad development occurred in low water. Females presented higher reproductive investment than males, which allocated most of energy for somatic development. This strategy could be a mechanism to undergo the stress caused by oligotrophic characteristics of the reservoir enhanced during low water level.Efeitos do nível da água na condição de Geophagus brasiliensis foram analisados em um reservatório oligotrófico. A condição fisiológica (K e o índice gonadossomático (IGS foram comparados entre os níveis da água (baixo e alto. Melhores condições de fêmeas foram associadas a maiores disponibilidades de recursos no nível alto, já que o desenvolvimento gonadal não variou. Não foram registradas diferenças na condição de machos, contudo maiores valores de IGS ocorreram no nível baixo. Fêmeas apresentaram elevado investimento reprodutivo, enquanto machos investiram mais no desenvolvimento somático. Tal estratégia pode ser um mecanismo para suportar o estresse causado pelas características oligotróficas do reservatório, intensificadas durante o período de níveis baixos da água.

  17. Evaluation of the Chemcatcher and DGT passive samplers for monitoring metals with highly fluctuating water concentrations.

    Science.gov (United States)

    Allan, Ian J; Knutsson, Jesper; Guigues, Nathalie; Mills, Graham A; Fouillac, Anne-Marie; Greenwood, Richard

    2007-07-01

    Passive sampling devices accumulate chemicals continuously from water and can provide time weighted average (TWA) concentrations of pollutants over the exposure period. Hence, they offer a number of advantages over other conventional monitoring techniques such as spot or grab sampling. The diffusive gradient in thin film (DGT) and the Chemcatcher passive samplers can be used to provide TWA concentrations of labile metals, but the approaches to their calibration differ. DGT uses diffusion coefficients of metals in the hydrogel layer, whereas Chemcatcher uses metal specific uptake rates, with both sets of values obtained under controlled laboratory conditions with constant aqueous metal concentrations. However, little is known of how such samplers respond to fluctuating concentrations. We evaluated the responsiveness of these two passive sampling devices to rapidly changing concentrations of Cd, Cu, Ni, Pb and Zn in natural freshwater, over a relatively short deployment time. Maximum metal concentrations in water were varied between 70 and 140 microg L(-1). Experiments were carried out in a tank with a rotating carousel system and filled with Meuse river water, allowing a degree of control over experimental conditions while using natural river water. Fluctuating concentrations were obtained by stepwise addition of standard solutions of the metals. The reliability and accuracy of the TWA concentrations measured by the samplers were assessed by comparison with concentrations of the metals in spot samples of water taken regularly over the deployment period. The spot samples of water were either unfiltered (total), filtered (0.45 microm) or ultrafiltered (5 kDa). Predictive speciation modelling using the visual MINTEQ programme was also undertaken. There was reasonable agreement between the TWA concentrations of Cd and Ni obtained with Chemcatcher and DGT and the total Cd and Ni concentrations measured in repeated unfiltered spot samples. For elements (i.e. Cu, Pb, Zn) that associate to a significant degree with suspended solids, colloids or dissolved organic carbon, or form complexes with large organic ligands, optimum agreement was with the filtered or ultrafiltered fractions and with the predicted inorganic and inorganic-fulvic acid associated fractions. While Chemcatcher-based TWA concentration ranges for Cu and Zn were in best agreement with the total filtered fraction, there was lack of agreement for Pb. The combined use of DGT devices with open pore (OP) and restricted pore (RP) gels allowed the labile fraction of metal associated with large organic ligands or DOC to be differentiated and quantified, since this is available to DGT OP but unable to diffuse into the DGT RP. This evaluation of the two sampling devices clearly demonstrated their ability to react reliably to transient peaks in concentration of metal pollutants in water and indicated where future efforts are needed to improve calibration data. Such samplers may prove valuable in responding to the monitoring requirements of the European Union's Water Framework Directive. PMID:17607387

  18. Gravimetric response of water table fluctuations in the Sahelian Diffa site (East Niger): local effects including poro-elasticity

    Science.gov (United States)

    Hector, B.; Genthon, P.; Le Coz, M.; Hinderer, J.; Chalikakis, K.; Descloitres, M.

    2010-12-01

    The GHYRAF project (Gravimetry and HYdrology in AFrica) is devoted to a regional study of the relationship between hydrological and gravimetric signals in the Western African Monsoon area. Three sites are monitored in a decreasing pluviometric gradient: Djougou (North Benin), Wankama (Niamey area) and Bagara (Eastern Niger) with annual rainfalls amounting to 1200 mm, 600 mm and 350 mm, respectively. The Diffa/Bagara site is located 640m away from the Yobé temporary river, a tributary of Lake Chad fed by rainfall on the Jos Plateau (Nigeria) and that is generally flowing between mid July and January. Apart from this period, the river bed includes a series of ponds that form the top of the aquifer and that are pumped for intensive irrigated cropping. The 50m thick uppermost unconfined aquifer is locally recharged by the Yobé River and is flowing northwards. It has been explored by geophysical methods involving RMS and TDEM soundings, which provided information on its porosity and electrical conductivity, respectively. A series of nearly 50 holes drilled down to a 10 m depth in the Bagara area allowed to define the detailed sedimentary structure of the aquifer. It consists mainly of fluvial deposits with alternating layers of fine sands, coarse grained sands and clays. The sedimentary pile includes clayed layer of centimetric to metric thickness with a mean lateral extension of 300 m. The groundwater level is monitored by a series of 4 piezometers located at 25 m, 270 m, 500 m and 640 m from the river axis. The shape of the piezometric curve at the Bagara station is 0.4 m amplitude sinusoid and presents a maximum level at mid January and a minimum one near mid July. Clearly, water level fluctuations are governed by infiltration from the Yobe river with an offset controlled by the distance to it. With the 20% porosity measured by MRS, this would imply a nearly 30 nms-2 gravimetric signal, which is in fair agreement with the observed amplitude. However both the observed gravimetic signal and the results of the global hydrological model GLDAS are offset with respect to the piezometric one. In order to assess the influence of local effects, the groundwater level is modeled with the USGS finite-difference ModFlow code using different properties sets of the aquifer deduced from statistical analysis of drill-holes data. Poroelasticity effects resulting from variable saturation of the clay layers observed near the water level on the Bagara site are assessed. The ability of gravity data for monitoring annual and long term water level changes in the uppermost aquifer is then discussed.

  19. Soil migration and plant uptake of technetium from a fluctuating water table

    International Nuclear Information System (INIS)

    Soil columns (50 x 15 cm) were used to determine the potential for 95mTc (as a surrogate for 99Tc which is an important component of some radioactive waste) to migrate from a contaminated, fluctuating water table, through sandy loam soil and into perennial ryegrass. Upward migration was significantly retarded with, generally, only the bottom few centimetres of soil becoming contaminated over the 6 months of the experiment. This is thought to have been due to the presence of anoxic conditions within the water table leading to the reduction of pertechnetate to TcIV species which are relatively insoluble. However, some evidence of very slow upward migration over time was found. Only a small and inconsistent transfer of activity into the perennial ryegrass was observed. Whilst these observations would suggest that 99Tc is less important than radionuclides such as 129I and 36Cl in terms of the risk associated with radioactive waste disposal, the potential for a slow upward migration, and/or a pulse-release following the re-oxidation of reduced soil in which 99Tc has accumulated should not be overlooked

  20. Effects of Water Levels on Productivity of Canada Geese in the Northern Flathead Valley, Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Daniel

    1987-08-01

    The Fish and Wildlife Program of the Northwest Power Planning Council calls for wildlife mitigation at hydroelectric projects in the Columbia River System. Beginning April, 1984, the Bonneville Power Administration funded a study of the effects of the operation of Hungry Horse and Kerr Dams on the western Canada goose (Branta canadensis moffittii) inhabitating the Flathead Valley of northwest Montana. The study was conducted by personnel of the Montana Department of Fish, Wildlife and Parks (MDFWP), to: (1) identify the size and productivity of this population, (2) identify current habitat conditions and losses of nesting and brood-rearing areas, (3) describe the effects of water level fluctuations on nesting and brood-rearing, and (4) identify mitigation alternatives to offset these effects. Annual pair and nest surveys were used to document the location and fate of goose nests. The number of known nesting attempts varied from 44 in 1984 to 108 in 1985, to 136 in 1986 and 134 in 1987. Fifty-four percent of the annual meeting nesting effort took place on elevated sites which were secure from the flooding and dewatering effects of fluctuating water levels. An average of 15 nests were found on stumps in the remnant Flathead River delta, however, an area strongly influenced by the operation of Kerr Dam. Annual nest losses to flooding and predation attributable to fluctuations caused by the dam were recorded. 53 refs., 24 figs., 35 tabs.

  1. Water levels in the Yucca Mountain Area, Nevada, 1996

    International Nuclear Information System (INIS)

    Water levels were monitored in 24 wells in the Yucca Mountain area, Nevada, during 1996. Twenty-two wells representing 28 depth intervals were monitored periodically, generally on a monthly basis, and 2 wells representing 3 depth intervals were monitored both hourly and periodically. All wells monitor water levels in Tertiary volcanic rocks except one that monitors water levels in paleozoic carbonate rocks. Water levels were measured using either calibrated steel tapes or a pressure sensor. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 727.86 to about 1,034.58 meters above sea level during 1996. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 752.57 meters above sea level during 1996. Mean water-level altitudes for 1996 were an average of about 0.06 meter lower than 1995 mean water-level altitudes and 0.03 meter lower than 1985--95 mean water-level altitudes. During 1996, water levels in the Yucca Mountain area could have been affected by long-term pumping at the C-hole complex that began on May 8, 1996. Through December 31, 1996, approximately 196 million liters were pumped from well UE-25 c number-sign 3 at the C-hole complex. Other ground-water pumpage in the Yucca Mountain area includes annual pumpage from water-supply wells UE-25 J-12 and UE-25 J-13 of approximately 163 and 105 million liters, respectively, and pumpage from well USW G-2 for hydraulic testing during February and April 1996 of approximately 6 million liters

  2. Water levels in the Yucca Mountain area, Nevada, 1995

    International Nuclear Information System (INIS)

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1995. Seventeen wells representing 18 depth intervals were monitored periodically, generally on a monthly basis, 2 wells representing 3 depth intervals were monitored hourly, and 9 wells representing 15 depth intervals were monitored both periodically and hourly. All wells monitor water levels in Tertiary volcanic rocks except one that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes, a multiconductor cable unit, and/or pressure transducers. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1995. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1995. Mean water level altitudes were only an average of about 0.01 meters higher than 1994 mean water level altitudes. A single-well aquifer test was conducted on well UE-25 WT number-sign 12 during August and September 1995. Well USW 0-2 was also pumped during October and November 1995, in preparation for single-well aquifer test at that well. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  3. Water levels in the Yucca Mountain area, Nevada, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Graves, R.P.; Tucci, P.; Goemaat, R.L.

    1996-12-31

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1994. Twelve wells representing 13 intervals were monitored periodically, generally on a monthly basis, 6 wells representing 10 intervals were monitored hourly, and 10 wells representing 13 intervals were monitored both periodically and hourly. All wells monitor water levels in Tertiary volcanic rocks, except one, that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes, a multiconductor cable unit, and pressure transducers. Water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1994. The mean-annual water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1994. Water levels were only an average of about 0.01 meters lower than 1993 water levels. All data were acquired in accordance with a quality-assurance program to support the reliability of the data.

  4. Water levels in the Yucca Mountain area, Nevada, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Graves, R.P.; Goemaat, R.L.

    1998-09-01

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1995. Seventeen wells representing 18 depth intervals were monitored periodically, generally on a monthly basis, 2 wells representing 3 depth intervals were monitored hourly, and 9 wells representing 15 depth intervals were monitored both periodically and hourly. All wells monitor water levels in Tertiary volcanic rocks except one that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes, a multiconductor cable unit, and/or pressure transducers. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1995. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1995. Mean water level altitudes were only an average of about 0.01 meters higher than 1994 mean water level altitudes. A single-well aquifer test was conducted on well UE-25 WT{number_sign}12 during August and September 1995. Well USW 0-2 was also pumped during October and November 1995, in preparation for single-well aquifer test at that well. All data were acquired in accordance with a quality-assurance program to support the reliability of the data.

  5. Water levels in the Yucca Mountain area, Nevada, 1994

    International Nuclear Information System (INIS)

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1994. Twelve wells representing 13 intervals were monitored periodically, generally on a monthly basis, 6 wells representing 10 intervals were monitored hourly, and 10 wells representing 13 intervals were monitored both periodically and hourly. All wells monitor water levels in Tertiary volcanic rocks, except one, that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes, a multiconductor cable unit, and pressure transducers. Water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1994. The mean-annual water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1994. Water levels were only an average of about 0.01 meters lower than 1993 water levels. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  6. The effect of wind speed fluctuations on the performance of a wind-powered membrane system for brackish water desalination

    OpenAIRE

    Park, Gavin L.; Scha?fer, Andrea; Richards, Bryce S.

    2011-01-01

    A wind-powered reverse osmosis membrane (wind-membrane) system without energy storage was tested using synthetic brackish water (2750 and 5500 mg/L NaCl) over a range of simulated wind speeds under both steady-state and fluctuating conditions. The parameters varied were: i) average wind speed from 3.7 (system start-up) to 8.7 m/s; ii) wind turbulence intensity from 0.0 (steady-state conditions) to 0.6 (extreme fluctuations); and iii) period of oscillation from 15 to 90 s. With ...

  7. The role of patterning in peatland water table fluctuations and carbon exchange

    Science.gov (United States)

    Wilson, P.; Shatilla, N.; Roulet, N. T.

    2010-12-01

    Peatlands store 30% of global terrestrial organic carbon. At the Mer Bleue research site in southern Canada (45.40° N, 75.50° W), it has been shown that changes in water storage affect carbon fluxes in and out of the peatland. The water table is an indicator of moisture storage in the bog and it influences the four carbon pathways that make up the Net Ecosystem Carbon Balance (NECB): dissolved organic carbon, gross primary productivity, respiration (aerobic and anaerobic) and methane production, oxidation and transport. Mer Bleue has a distinct hummock - hollow surface topography. The micro-topographical features affect the temporal and spatial variations in water table. We have begun sampling the temporal and spatial variations on two separate plots with varying degrees of micro-topographic relief. Each plot has 100 manual observation wells in a 2 x 2 metre grid that have been sampled every 2-3 weeks and several transects of 4-7 automatic capacitative data loggers, continuously recording water levels every 15 minutes. The continuous water table measurements were situated to maximize the difference in elevation between adjacent hummocks and hollows. Our results indicate that the spatial pattern of the water table at any given time is a subdued reflection of the surface topography - i.e. greater depth under hummocks than hollows. The continuous water table measurements show that the variations in water table, while synchronized, differ in their magnitude of variation depending on topography. When combined with the surface elevation the patterns in time and space can be used to provide a tempo-spatial ecologically meaningful measure of water storage, explain the feedbacks between moisture and peat accumulation, and suggest a basis for scaling point measurements to account for topographic variations.

  8. Short-time variations of the ground water level

    International Nuclear Information System (INIS)

    Investigations have demonstrated that the ground water level of aquifers in the Swedish bedrock shows shorttime variations without changing their water content. The ground water level is among other things affected by regular tidal movements occuring in the ''solid'' crust of the earth variations in the atmospheric pressure strong earthquakes occuring in different parts of the world These effects proves that the system of fissures in the bedrock are not stable and that the ground water flow is influenced by both water- and airfilled fissures

  9. Global land water storage change from GRACE over 2002-2009; Inference on sea level

    Science.gov (United States)

    Llovel, William; Becker, Mélanie; Cazenave, Anny; Crétaux, Jean-François; Ramillien, Guillaume

    2010-03-01

    Global change in land water storage and its effect on sea level is estimated over a 7-year time span (August 2002 to July 2009) using space gravimetry data from GRACE. The 33 World largest river basins are considered. We focus on the year-to-year variability and construct a total land water storage time series that we further express in equivalent sea level time series. The short-term trend in total water storage adjusted over this 7-year time span is positive and amounts to 80.6 ± 15.7 km 3/yr (net water storage excess). Most of the positive contribution arises from the Amazon and Siberian basins (Lena and Yenisei), followed by the Zambezi, Orinoco and Ob basins. The largest negative contributions (water deficit) come from the Mississippi, Ganges, Brahmaputra, Aral, Euphrates, Indus and Parana. Expressed in terms of equivalent sea level, total water volume change over 2002-2009 leads to a small negative contribution to sea level of -0.22 ± 0.05 mm/yr. The time series for each basin clearly show that year-to-year variability dominates so that the value estimated in this study cannot be considered as representative of a long-term trend. We also compare the interannual variability of total land water storage (removing the mean trend over the studied time span) with interannual variability in sea level (corrected for thermal expansion). A correlation of ˜0.6 is found. Phasing, in particular, is correct. Thus, at least part of the interannual variability of the global mean sea level can be attributed to land water storage fluctuations.

  10. Animating ground water levels with Excel.

    Science.gov (United States)

    Shikaze, Steven G; Crowe, Allan S

    2003-01-01

    This note describes the use of Microsoft Excel macros (programs written in Excel's internal language, Visual Basic for Applications) to create simple onscreen animations of transient ground water data within Excel. Compared to many specialized visualization software packages, the use of Excel macros is much cheaper, much simpler, and can rapidly be learned. The Excel macro can also be used to create individual GIF files for each animation frame. This series of frames can then be used to create an AVI video file using any of a number of graphics packages, such as Corel PhotoPaint. The technique is demonstrated through a macro that animates changes in the elevation of a water table along a transect over several years. PMID:12873018

  11. Synthesis water level control by fuzzy logic

    OpenAIRE

    Berk, P.; D. Stajnko; P. Vindis; B. Mursec; M. Lakota

    2011-01-01

    Purpose: This paper focuses on evolving of two types fuzzy and classical PID liquid level controller and examining whether they are better able to handle modelling uncertainties. A two stage strategy is employed to design the synthesis fuzzy and classical PID controller with the process of the first and second order and implements disorder (quadratic function).Design/methodology/approach: The synthesis of fuzzy and classical PID liquid level controller was realized with the HP laptop 6830s Co...

  12. Characteristic of water level changes in river-bed during the 2012 drought in context of ground water levels in a small catchment

    Science.gov (United States)

    Wasilewicz, Micha?; Kaznowska, Ewa; Hejduk, Leszek

    2014-05-01

    The objective of this paper is to characterize the water level changes in river bed during the 2012 drought, in the context of ground water levels in the catchment. During the growing season , and long- lasting lack of precipitation causes atmospheric drought. Prolonged lack of precipitation causes depletion of water resources in the saturated zone . Groundwater recharge of rivers decreases , and hence streamflow droughts (summer droughts) occur, which is identified as hydrological droughts. In the phase of hydrological drought a much stronger relationship between surface and ground waters is observed. The study area is the Zago?d?onka river. The Zago?dzonka catchment is situated in the strip of the Central Polish Lowlands, in the region where droughts are the most frequent. The basin is the research area of the Department of Hydraulic Engineering of WUoLS-SGGW in Warsaw. It is one of the few catchments in Poland, with long-term records of rainfall and runoff occurrences. Hydrometeorological measurements are carried out from July 1962. The catchment area is mainly covered by one Quaternary aquifer . Quaternary layer is composed mostly of Pleistocene sands and gravels, with thickness from 4 to 40 m. Aquifer is at a depth of 1 to 12 m below ground level and is unconfined and fed by direct infiltration of precipitation. The Zago?d?onka river is the main drainage in the local hydrologic cycle. There is a strong relationship between surface waters and occurring in the Quaternary sediments. In the hydrological year 2012 hydrological and atmospheric drought occurred. The duration and deficit of streamflow drought ( defined by with the Q90 % truncation level) in 2012 was three time greater than the average value from the multi-annual period, which influenced the groundwater level fluctuations. Acknowledgment The paper has been prepared with financial support by a grant from National Science Centre

  13. Sensitivity of polarization fluctuations to the nature of protein-water interactions: Study of biological water in four different protein-water systems

    Science.gov (United States)

    Ghosh, Rikhia; Banerjee, Saikat; Hazra, Milan; Roy, Susmita; Bagchi, Biman

    2014-12-01

    Since the time of Kirkwood, observed deviations in magnitude of the dielectric constant of aqueous protein solution from that of neat water (˜80) and slower decay of polarization have been subjects of enormous interest, controversy, and debate. Most of the common proteins have large permanent dipole moments (often more than 100 D) that can influence structure and dynamics of even distant water molecules, thereby affecting collective polarization fluctuation of the solution, which in turn can significantly alter solution's dielectric constant. Therefore, distance dependence of polarization fluctuation can provide important insight into the nature of biological water. We explore these aspects by studying aqueous solutions of four different proteins of different characteristics and varying sizes, chicken villin headpiece subdomain (HP-36), immunoglobulin binding domain protein G (GB1), hen-egg white lysozyme (LYS), and Myoglobin (MYO). We simulate fairly large systems consisting of single protein molecule and 20000-30000 water molecules (varied according to the protein size), providing a concentration in the range of ˜2-3 mM. We find that the calculated dielectric constant of the system shows a noticeable increment in all the cases compared to that of neat water. Total dipole moment auto time correlation function of water ??MW(0)?MW(t)? is found to be sensitive to the nature of the protein. Surprisingly, dipole moment of the protein and total dipole moment of the water molecules are found to be only weakly coupled. Shellwise decomposition of water molecules around protein reveals higher density of first layer compared to the succeeding ones. We also calculate heuristic effective dielectric constant of successive layers and find that the layer adjacent to protein has much lower value (˜50). However, progressive layers exhibit successive increment of dielectric constant, finally reaching a value close to that of bulk 4-5 layers away. We also calculate shellwise orientational correlation function and tetrahedral order parameter to understand the local dynamics and structural re-arrangement of water. Theoretical analysis providing simple method for calculation of shellwise local dielectric constant and implication of these findings are elaborately discussed in the present work.

  14. Keeping fuel covered. ABB's new water level measurement system

    International Nuclear Information System (INIS)

    As one of the basic principles of reactor safety is to ensure that the fuel is covered, knowing water levels is vital. Older designs of water measurement equipment can suffer errors caused by the presence of non-condensable gases in the water during a depressurization transient. ABB Atom's new level measuring system, which uses an advanced condensation pot, is virtually independent of any variation of gas content. (UK)

  15. Quality Level of Bottled Drinking Water Consumed in Saudi Arabia

    OpenAIRE

    Ashraf E.M. Khater; Asma Al-Jaloud; A. El-Taher

    2014-01-01

    The quality of drinking water is a universal health concern and access to safe water is a fundamental human right. Many national and international organizations set certain parameters and levels for Bottled Drinking Water (BDW) to ensure their quality. The present work aims to analyze the quality of various brands of BDW used in Saudi Arabia and to compare the quality levels to the BDW standards. One hundred and twenty six samples of 54 different BDW brands were ...

  16. EFECTOS DE LA FLUCTUACIÓN DEL NIVEL DEL AGUA SOBRE LA ESTRUCTURA DEL ENSAMBLAJE DE ROTÍFEROS EN EL LAGO LARGO (SISTEMA YAHUARCACA - LLANURA DE INUNDACIÓN DEL RÍO AMAZONAS - COLOMBIA) / Effects of water level fluctuation on rotifers assemblage structure in Largo lake (Yahuarcaca sistem - river Amazon floodplain - Colombia)

    Scientific Electronic Library Online (English)

    CAMILO, ANDRADE-SOSSA; MIGDALIA, GARCÍA-FOLLECO; CARLOS A., RODRÍGUEZ-MUNAR; SANTIAGO R., DUQUE; EMILIO, REALPE.

    2011-12-30

    Full Text Available Se realizó un reconocimiento taxonómico y estimación de la densidad en el ensamblaje de rotíferos en el lago Largo, del sistema de lagos Yahuarcaca, en la ribera colombiana del río Amazonas, a partir de muestreos en las fases hidrológicas de aguas bajas, ascenso y descenso. Se identificaron 68 espec [...] ies, 28 de ellas son nuevos registros para ambientes colombianos. Se encontró aumento en la riqueza en las épocas de ascenso y descenso, siendo mayor en la zona litoral respecto de la limnética, y la tendencia a mayor similitud taxonómica entre ambas zonas en el periodo de aguas bajas, debido al mínimo desarrollo de macrófitas en esta fase y la consecuente menor heterogeneidad espacial. Se observó el predominio de rotíferos con trofi adaptados para moler y triturar partículas (maleado y maleorramado) en las épocas de aguas bajas (Brachionus ahlstromi) y descenso (Filina saltator) y en la época de ascenso de Polyarthra vulgaris, con trofi adaptado para perforar y succionar fluidos de algas y otros organismos (virgado) y apéndices que favorecen la rápida natación. En general, se establecieron posibles relaciones entre la riqueza y la densidad de rotíferos con cambios en características como el desarrollo de vegetación acuática en el litoral, profundidad del lago, nivel de conectividad con los otros lagos del sistema Yahuarcaca, influencia de aguas blancas del Amazonas y negras de origen local, potenciales recursos nutricionales y depredadores, y posible efecto de arrastre por la corriente. Abstract in english We conducted a taxonomic recognition and density estimation of the assemblage of rotifers in Lake Largo, in the floodplain system of Yahuarcaca, connected with the Amazon River, in Colombia. Two samplings were made for each hydrological phase (low water, filling and draining phases); 68 species were [...] identified, 28 of them are new records for Colombian environments. We found an increased in species richness in the filling and draining phases, being higher in the littoral than in limnetic region, and a tendency to a higher taxonomic similarity between the two areas during low water periods, due to the reduced macrophyte development in that period and consequent reduced spatial heterogeneity. We observed the predominance of rotifers with trophi adapted for grinding and crushing particles (malleate and malleorramate) in low water phase (Brachionus ahlstromi) and draining phase (Filina saltator) and Polyarthra vulgaris, with a trophi adapted to pierce and suck out the fluids of algae and other organisms (virgate), and appendices that support the rapid swimming, at the filling phase. In general, we established possible relations between rotifers richness and density with changes in characteristics as the development of aquatic vegetation in the littoral zone, lake depth, level of connectivity with other lakes of Yahuarcaca system, level of influence of white waters from the Amazon river, and black waters from local origin, potentials nutritional resources and predators, and drag effect by the current.

  17. Predicting water-surface fluctuation of continental lakes: A RS and GIS based approach in Central Mexico

    Science.gov (United States)

    Mendoza, M.E.; Bocco, G.; Bravo, M.; Lopez, Granados E.; Osterkamp, W.R.

    2006-01-01

    Changes in the water-surface area occupied by the Cuitzeo Lake, Mexico, during the 1974-2001 period are analysed in this study. The research is based on remote sensing and geographic information techniques, as well as statistical analysis. High-resolution satellite image data were used to analyse the 1974-2000 period, and very low-resolution satellite image data were used for the 1997-2001 period. The long-term analysis (1974-2000) indicated that there were temporal changes in the surface area of the Cuitzeo Lake and that these changes were related to precipitation and temperatures that occurred in the previous year. Short-term monitoring (1997-2001) showed that the Cuitzeo Lake surface is lowering. Field observations demonstrated also that yearly desiccation is recurrent, particularly, in the western section of the lake. Results suggested that this behaviour was probably due to a drought period in the basin that began in the mid 1990s. Regression models constructed from long-term data showed that fluctuations of lake level can be estimated by monthly mean precipitation and temperatures of the previous year. ?? Springer Science + Business Media, Inc. 2006.

  18. Analysis of Ground-Water Levels and Associated Trends in Yucca Flat, Nevada Test Site, Nye County, Nevada, 1951-2003

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Fenelon

    2005-10-05

    Almost 4,000 water-level measurements in 216 wells in the Yucca Flat area from 1951 to 2003 were quality assured and analyzed. An interpretative database was developed that describes water-level conditions for each water level measured in Yucca Flat. Multiple attributes were assigned to each water-level measurement in the database to describe the hydrologic conditions at the time of measurement. General quality, temporal variability, regional significance, and hydrologic conditions are attributed for each water-level measurement. The database also includes narratives that discuss the water-level history of each well. Water levels in 34 wells were analyzed for variability and for statistically significant trends. An attempt was made to identify the cause of many of the water-level fluctuations or trends. Potential causes include equilibration following well construction or development, pumping in the monitoring well, withdrawals from a nearby supply well, recharge from precipitation, earthquakes, underground nuclear tests, land subsidence, barometric pressure, and Earth tides. Some of the naturally occurring fluctuations in water levels may result from variations in recharge. The magnitude of the overall water-level change for these fluctuations generally is less than 2 feet. Long-term steady-state hydrographs for most of the wells open to carbonate rock have a very similar pattern. Carbonate-rock wells without the characteristic pattern are directly west of the Yucca and Topgallant faults in the southwestern part of Yucca Flat. Long-term steady-state hydrographs from wells open to volcanic tuffs or the Eleana confining unit have a distinctly different pattern from the general water-level pattern of the carbonate-rock aquifers. Anthropogenic water-level fluctuations were caused primarily by water withdrawals and nuclear testing. Nuclear tests affected water levels in many wells. Trends in these wells are attributed to test-cavity infilling or the effects of depressurization following nuclear testing. The magnitude of the overall water-level change for wells with anthropogenic trends can be large, ranging from several feet to hundreds of feet. Vertical water-level differences at 27 sites in Yucca Flat with multiple open intervals were compared. Large vertical differences were noted in volcanic rocks and in boreholes where water levels were affected by nuclear tests. Small vertical differences were noted within the carbonate-rock and valley-fill aquifers. Vertical hydraulic gradients generally are downward in volcanic rocks and from pre-Tertiary clastic rocks toward volcanic- or carbonate-rock units.

  19. Analysis of ground-water levels and associated trends in Yucca Flat, Nevada Test Site, Nye County, Nevada, 1951-2003

    Science.gov (United States)

    Fenelon, Joseph M.

    2005-01-01

    Almost 4,000 water-level measurements in 216 wells in the Yucca Flat area from 1951 to 2003 were quality assured and analyzed. An interpretative database was developed that describes water-level conditions for each water level measured in Yucca Flat. Multiple attributes were assigned to each water-level measurement in the database to describe the hydrologic conditions at the time of measurement. General quality, temporal variability, regional significance, and hydrologic conditions are attributed for each water-level measurement. The database also includes narratives that discuss the water-level history of each well. Water levels in 34 wells were analyzed for variability and for statistically significant trends. An attempt was made to identify the cause of many of the water-level fluctuations or trends. Potential causes include equilibration following well construction or development, pumping in the monitoring well, withdrawals from a nearby supply well, recharge from precipitation, earthquakes, underground nuclear tests, land subsidence, barometric pressure, and Earth tides. Some of the naturally occurring fluctuations in water levels may result from variations in recharge. The magnitude of the overall water-level change for these fluctuations generally is less than 2 feet. Long-term steady-state hydrographs for most of the wells open to carbonate rock have a very similar pattern. Carbonate-rock wells without the characteristic pattern are directly west of the Yucca and Topgallant faults in the southwestern part of Yucca Flat. Long-term steady-state hydrographs from wells open to volcanic tuffs or the Eleana confining unit have a distinctly different pattern from the general water-level pattern of the carbonate-rock aquifers. Anthropogenic water-level fluctuations were caused primarily by water withdrawals and nuclear testing. Nuclear tests affected water levels in many wells. Trends in these wells are attributed to test-cavity infilling or the effects of depressurization following nuclear testing. The magnitude of the overall water-level change for wells with anthropogenic trends can be large, ranging from several feet to hundreds of feet. Vertical water-level differences at 27 sites in Yucca Flat with multiple open intervals were compared. Large vertical differences were noted in volcanic rocks and in boreholes where water levels were affected by nuclear tests. Small vertical differences were noted within the carbonate-rock and valley-fill aquifers. Vertical hydraulic gradients generally are downward in volcanic rocks and from pre-Tertiary clastic rocks toward volcanic- or carbonate-rock units.

  20. Long-term fluctuations of water resources availability and its implications for a sustainable management of arid agricultural coastal regions

    Science.gov (United States)

    Grundmann, Jens; Schütze, Niels

    2015-04-01

    Freshwater scarcity and ongoing population growth associated with increasing water demands are major challenges for water management in coastal arid regions. Excessive use of groundwater for irrigation in agriculture puts those regions at risk of saltwater intrusion which limits agricultural opportunities. Additionally, some arid regions are characterised by a cyclic climate in which longer periods of dry years are followed by longer periods of wet years. This results also in long-term fluctuations of groundwater replenishment rates and water resources availability which may reach the same order of magnitude like long-term average values. Therefore, these long-term fluctuations should be considered for water resources management planning and operation. In order to evaluate their impact a simulation-based integrated water management system for coastal arid regions is used. The management system couples a groundwater module, assessing the water resources availability, and an agricultural module, controlling irrigation and cultivation within an optimisation module which allow for multi-objective optimisation of the water management regarding profitable and sustainable water resources and agricultural management on farm and regional scale. To achieve a fast and robust operation of the water management system, surrogate models are used which emulate the behaviour of physically based process models and a hierarchical optimisation scheme is applied. The water management system is driven by different scenarios of the water resources availability which were generated by using time series analyses and modelling of local groundwater replenishment rates. An application is performed for the south Batinah coastal region in the Sultanate of Oman which is affected by saltwater intrusion into a coastal aquifer system due to excessive groundwater withdrawal for irrigated agriculture. Several scenarios of water resources availability are used to compare long-term and adaptive management strategies and to demonstrate and to evaluate the impact of climate variability regarding agricultural profit and sustainable aquifer management.

  1. Fluctuation properties of laser light after interaction with an atomic system: comparison between two-level and multilevel atomic transitions

    CERN Document Server

    Lezama, A; Kastberg, A; Tanzilli, S; Kaiser, R

    2015-01-01

    The complex internal atomic structure involved in radiative transitions has an effect on the spectrum of fluctuations (noise) of the transmitted light. A degenerate transition has different properties in this respect than a pure two-level transition. We investigate these variations by studying a certain transition between two degenerate atomic levels for different choices of the polarization state of the driving laser. For circular polarization, corresponding to the textbook two-level atom case, the optical spectrum shows the characteristic Mollow triplet for strong laser drive, while the corresponding noise spectrum exhibits squeezing in some frequency ranges. For a linearly polarized drive, corresponding to the case of a multilevel system, additional features appear in both optical and noise spectra. These differences are more pronounced in the regime of a weakly driven transition: whereas the two-level case essentially exhibits elastic scattering, the multilevel case has extra noise terms related to sponta...

  2. Synthesis water level control by fuzzy logic

    Directory of Open Access Journals (Sweden)

    P. Berk

    2011-04-01

    Full Text Available Purpose: This paper focuses on evolving of two types fuzzy and classical PID liquid level controller and examining whether they are better able to handle modelling uncertainties. A two stage strategy is employed to design the synthesis fuzzy and classical PID controller with the process of the first and second order and implements disorder (quadratic function.Design/methodology/approach: The synthesis of fuzzy and classical PID liquid level controller was realized with the HP laptop 6830s Compaq NA779ES, software Matlab/Simulink 2008b, FIS (Fuzzy Inference System soft logical tool, input-output unit 500 Dragon Rider and ultrasonic sensor. Using the simulation program Matlab/Simulink/FIS we simulate the operation of fuzzy and classical controller in the liquid level regulating cycle and made a comparison between fuzzy and classical controller functioning.Findings: From the responses to step fuzzy and classical controller for first-order process shows that the actual value of the controlled variable takes the value one. Fuzzy and classical PID controller does not allow control derogation, which is also inappropriate for fuzzy and classical control cycle with incorporating disturbance. Classical PID controller in the first-order process provides short-term regulation, such as fuzzy PID controller. In fuzzy control cycle with fuzzy PID controller and incorporating disturbance in the process of second-order the control cycle is stable and at certain predetermined parameters (integral gain a control does not allow deviations.Research limitations/implications: In future research, the robustness of the fuzzy logic controller will be investigated in more details.Practical implications: Using fuzzy liquid level controller can reduce power consumption by 25%. Originality/value: Fuzzy logic controller is useful in applications of nonlinear static characteristic, where classical methods with usually classical PID controllers cannot be a satisfactory outcome

  3. Density fluctuations in aqueous solution of ionic liquid with lower critical solution temperature: Mixture of tetrabutylphosphonium trifluoroacetate and water

    Science.gov (United States)

    Nitta, Ayako; Morita, Takeshi; Saita, Shohei; Kohno, Yuki; Ohno, Hiroyuki; Nishikawa, Keiko

    2015-05-01

    Aqueous solutions of tetrabutylphosphonium trifluoroacetate ([P4444]CF3COO) exhibit a LCST-type phase transition with the critical point near 0.025 in mole fraction of [P4444]CF3COO at T = 302 K. The phase behavior of [P4444]CF3COO-water mixtures was investigated by evaluating their density fluctuations, which provide quantitative descriptions of the mixing states of the solutions. The concentration dependence of the density fluctuations was investigated at 293 and 301 K for the mixtures without distinguishing the components and for the individual components ([P4444]CF3COO and water). A drastic change in the mixing state was observed for the solution when the critical point was approached.

  4. Water-Level Changes in Shallow Wells Before and After the 1999 Ýzmit and Düzce Earthquakes and Comparison with Long-Term Water-Level Observations (1999-2004), NW Turkey.

    Science.gov (United States)

    Yaltirak, Cenk; Yalçin, Tolga; Yüce, Galiip; Bozkurto?lu, Erkan

    2005-12-01

    It is well known that earthquakes cause hydrological changes, such as drying or flooding of water wells, fluctuations in ground-water levels in wells, changes in water quality, and formation of new springs. Significant drops in ground-water levels in wells were recorded during recent earthquakes in NW Turkey on August 17, 1999 in Ýzmit and on November 12, 1999 in Düzce. The Ýzmit earthquake (Ms 7.4) caused pre-seismic water-level changes in wells at Eskisehir, located 118-216 km away from the epicentre. Well-level changes in the Eskisehir, Sakarya, Bursa, Yalova, Yenisehir and Ýnegöl basins were recorded prior to and after the Düzce earthquake (Ms 7.2) as well. These changes are due to strain on the southern Marmara segments of the Thrace-Eskisehir Fault Zone (TEFZ), which is affected by deformation of the North Anatolian Fault Zone (NAFZ). Ground-water-level changes in wells prior to and after the earthquake away from the epicentre and the position of Eastern Marmara-Eskisehir region indicate a possible connection between well-level changes that respond to compressive and tensile stresses and shear strain away from active strike-slip faults. The wells, located in basins having an angular connection with the earthquake-producing main faults, completely activate only during major earthquakes. The wells showing anomalies prior to earthquakes are generally found near epicentres or in basins having an angular connection as stated above. The data collected after the 1999 anomalies up to September 2004 indicate that the 1999 anomalies are unique to that year. It was not difficult to separate the seasonal fluctuations of the water levels from the earthquake anomalies. In this context, it is concluded that the 1999 water level anomalies prior to the earthquake were the fast- and short-period signature of slow but long-term deformations that occurred over a large area.

  5. Water Pollution by Surfactants: Fluctuations Due to Tourism Exploitation in a Lagoon Ecosystem

    Directory of Open Access Journals (Sweden)

    Silvano E. Focardi

    2012-09-01

    Full Text Available This paper describes recent levels of surfactants measured in a coastal lagoon ecosystem highly stressed by human activites: the Orbetello lagoon (Southern Tuscany, Italy, Ramsar Site IT008. Significance of difference among concentrations measured before and after summertime are explored in order to evaluate effects related to tourism exploitation. Among surfactants, methylene blue active anionic substances (MBAS are selected as tracers for untreated discharges originated by domestic and urban activities. Water samplings were performed in 2011 following a randomly replicated nested logic model (n = 144. MBAS mean level of 0.070 mg.L–1 (–1 and 0.530 mg.L–1 (–1 are respectively recorded in June and October evidencing a significant increase after the touristic season. Possible MBAS concentration phenomena could be induced by different evaportaton rates among sampling stations and between winter and summer seasons and were evaluated, in this study, using water salinity as possible factor affecting samples segregations. Results evidence that differences of MBAS levels related to evaporation rates are trascurabile if compared to the variability induced by the presence of not-collected wastewater hot-spot pollution sources located closed around the urban settlement and along sandbars. Measured levels of surfactants could act negatively on living organisms both animals and plants contributing to affect Orbetello lagoon biodiversity. In this ecosystem, after the complete reorganization of urban wastewater treatment plants occured in 2008, further management actions should be focalized on reducing untreated sources of MBAS.

  6. Experimental study of the fluctuations of an upward air-water flow in the circular pipe

    International Nuclear Information System (INIS)

    Among all the interactions between fluids and mechanical structures, the author is in particular interested in decoupled random excitations due to a two-phase flow on a transverse mechanical structure. The aim of this work is to know the parameters of the two-phase flow which drive the excitation forces of the vibrational modes of these structures. The fluctuations of an upward bubble two-phase flow have been studied in a cylindrical pipe with and without barrier(s). Three measurements techniques have been used to determine the mean characteristics of the flow and the fluctuations of the liquid mass flux and of the liquid movement quantity (nuclear magnetic resonance), of the local void fraction (optical probe) and of the wall pressure (piezoelectric sensor). The obtained results show that the fluctuations of the mass fluxes and of the liquid movement quantities are mainly driven by the fluctuations of the surface void fractions and particularly when the mean void fraction is great. Similarly, the pressure fluctuations are strongly influenced by the surface void fraction fluctuations. In the case of a barrier context, an instability phenomenon, inducing a sudden rise of the void fraction fluctuations in the range of the mean void fraction between 5 and 20 per cent, has been observed. The presence of grids leads to the formation of strong amplitude peaks of the pressure spectra. The study on the evolution of these peaks in terms of gas and liquid velocities implies that the pressure fluctuations, caused by the phenomenon of releases of these two-phase flows, are mainly controlled by the velocity of this mixture and by the fluctuations of the surface void fraction. (author)

  7. Temporal scaling behavior of sea-level change in Hong Kong - Multifractal temporally weighted detrended fluctuation analysis

    Science.gov (United States)

    Zhang, Yuanzhi; Ge, Erjia

    2013-01-01

    The rise in global sea levels has been recognized by many scientists as an important global research issue. The process of sea-level change has demonstrated a complex scaling behavior in space and time. Large numbers of tide gauge stations have been built to measure sea-level change in the North Pacific Ocean, Indian Ocean, North Atlantic Ocean, and Antarctic Ocean. Extensive studies have been devoted to exploring sea-level variation in Asia concerning the Bohai Gulf (China), the Yellow Sea (China), the Mekong Delta (Thailand), and Singapore. Hong Kong, however, a mega city with a population of over 7 million situated in the mouth of the Pear River Estuary in the west and the South China Sea in the east, has yet to be studied, particularly in terms of the temporal scaling behavior of sea-level change. This article presents an approach to studying the temporal scaling behavior of sea-level change over multiple time scales by analyzing the time series of sea-level change in Tai Po Kou, Tsim Bei Tsui, and Quarry Bay from the periods of 1964-2010, 1974-2010, and 1986-2010, respectively. The detection of long-range correlation and multi-fractality of sea-level change seeks answers to the following questions: (1) Is the current sea-level rise associated with and responsible for the next rise over time? (2) Does the sea-level rise have specific temporal patterns manifested by multi-scaling behaviors? and (3) Is the sea-level rise is temporally heterogeneous in the different parts of Hong Kong? Multi-fractal temporally weighted de-trended fluctuation analysis (MF-TWDFA), an extension of multi-fractal de-trended fluctuation analysis (MF-DFA), has been applied in this study to identify long-range correlation and multi-scaling behavior of the sea-level rise in Hong Kong. The experimental results show that the sea-level rise is long-range correlated and multi-fractal. The temporal patterns are heterogeneous over space. This finding implies that mechanisms associated with the local ecological environment, hydrodynamic and morphodynamic processes, and human activities might have driven a distinct sea-level rise in Hong Kong.

  8. Diurnal lamotrigine plasma level fluctuations: clinical significance and indication of shorter half-life with chronic administration

    DEFF Research Database (Denmark)

    Nielsen, K.A.; Dahl, M.

    2008-01-01

    For therapeutic monitoring of antiepileptic drugs (AEDs), morning trough levels (MTLs) are generally used. For specific questions like verification of breakthrough seizures or reported toxicity, however, other measures such as minimal and maximal concentrations (C(min), C(max)) can be important and may require daily profiles. For clinical reasons, 20 daily profiles of lamotrigine (LTG) plasma levels were determined in nine patients. The results revealed fluctuations exceeding those expected from its elimination half-life (t(1/2)) of 22h as reported in the literature. Patients on twice-daily regimens without pharmacokinetic interactions exhibited C(min)/C(max) ratios between 0.62 and 0.69. Fluctuations were smaller in those co-medicated with valproate, and reached a ratio of 0.55 in those co-medicated with phenobarbital. The C(max) was as much as 58% above the MTL. Therefore, verification of complaints indicating toxicity requires determination of drug levels when the symptoms are present. Our findings indicate that the t(1/2) of LTG with chronic treatment is shorter than generally assumed, and suggest that a slow-release formulation could be helpful in achieving full seizure control in patients with a narrow individual therapeutic index for LTG Udgivelsesdato: 2008/10

  9. Fluctuations of Phytoplankton Community in the Coastal Waters of Caspian Sea in 2006

    Directory of Open Access Journals (Sweden)

    Siamak Bagheri

    2011-01-01

    Full Text Available Problem statement: The Caspian Sea ecosystem has been suffered with many problems since 1980s. Aanthropogenic pollution from heavy metals, hydrocarbons, pesticides, changes in the quantity of nutrient inputs by rivers, are significant threats to biodiversity and biological resources such as plankton structure in the Caspian Sea. According to the significant of phytoplankton community in marine system. The state of the fluctuations of phytoplankton communities of the southwestern Caspian Sea was investigated and compared with the findings of before 2006. Approach: Phytoplankton abundance and species composition of the Caspian Sea were evaluated by using samples collected at 12 stations along three transects. Samplings were conducted seasonal in 2006 at 5, 10, 20 and 50 m depth were fixed for each transect in the southwestern Caspian Sea. Results: A total of 39 species phytoplankton species were distinguished during 2006, the annual phytoplankton abundance were calculated as 57, 300±15,550 cells.l-1, which ranged from 89, 250±35, 062 cells.l-1 in September to 16, 200±6,664 cells.l-1 in February. The diatoms formed more than half of the total abundance (61% while cyanophytes were the second important group in view of contribution to total phytoplankton (26% in 2006. The study showed that diatoms Thalassionema nitzschioides, Cyclotella meneghiniana and cyanophyte Osillatoria sp. numerically dominated in this area. Conclusion: The study revealed that diatoms were higher than other groups of phytoplankton in 2006. The hydrology variation, increased fresh water inflow via rivers and a rise in nutrients concentrations have played important roles in blooming of phytoplankton species, e.g., the diatoms in this study, which is also known from other marines. Similar studies on determination of the effects of environmental degradation on phytoplankton and hydrological processes should be taken into account in near future.

  10. The Constant Levelers: Water, Ice, and Gravity

    Science.gov (United States)

    This site has information about the work of three of the agents of erosion in the Northern Cascade Range. Since much of the range is made up of exotic terrains that probably did not evolve on the same spot on the Earth as the present North Cascades, the geologists confine their view to some time since the earliest Tertiary. Within that time frame, they can speculatively recreate the North Cascade scene and ponder its erosional history. The erosional work of rivers has constantly been altered by volcanic activity and whatever drainage pattern was established. It was profoundly altered about 35 million years ago by the renewed volcanic activity of the Cascade Volcanic Arc. A section about how rivers erode describes differential erosion, stream capture, and base level. The section about glaciers explains how they are formed, how they do their work, and what is left behind. The section about the work of gravity focuses on creep and landslides.

  11. Natural C-14 variations and consequences for sea-level fluctuations and frequency analysis of periods of peat growth

    International Nuclear Information System (INIS)

    The rise in sea level during the past 18,000 years has been studied largely by means of radiocarbon dating. The question whether small fluctuations are superimposed on the steadily rising sea level is discussed. Support for this is the observed succession of clastic deposits and peat layers, resulting from alternating periods of transgressive and regressive activity. However, irregularities in the 14C time scale might not only give rise to apparent steps in the relative sea-level rise, but also to clustering of 14C dates of geological finds at certain 14C intervals. Therefore, until there is more evidence the succession of clastic deposits and peat layers is interpreted as caused by local disasters at certain times and random regressive peat growth during quiet periods. (Auth.)

  12. Carboxyhaemoglobin levels in water-pipe and cigarette smokers

    Scientific Electronic Library Online (English)

    Ansa, Theron; Cedric, Schultz; James A, Ker; Nadia, Falzone.

    2010-02-01

    Full Text Available Water-pipe smoking is growing in popularity, especially among young people, because of the social nature of the smoking session and the assumption that the effects are less harmful than those of cigarette smoking. It has however been shown that a single water-pipe smoking session produces a 24-hour [...] urinary cotinine level equivalent to smoking 10 cigarettes per day. AIM: We aimed to measure carboxyhaemoglobin (COHb) blood levels before and after water-pipe and cigarette smoking sessions. METHOD: Self-confessed smokers older than 18 years (N=30) volunteered to smoke a water-pipe or a cigarette and have their blood COHb levels measured under controlled conditions. RESULTS: Mean baseline COHb levels were 2.9% for the 15 cigarette smokers and 1.0% for the 15 water-pipe smokers. Levels increased by a mean of 481.7% in water-pipe smokers as opposed to 39.9% in cigarette smokers. CONCLUSION: The study demonstrated that water-pipe smokers had significantly higher increases in blood COHb levels thancigarette smokers during a single smoking session.

  13. Stability of a natural slope under combined effects of reservoir water level drawdown and rainfall infiltration

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Q. [Sichuan Univ., Chengdu, Sichuan (China). School of Hydraulic and Hydroelectric Engineering; Zhang, L. [Hong Kong Univ. of Science and Technology, Hong Kong (China). Dept. of Civil Engineering

    2005-07-01

    Several large-scale soil slopes were immersed when China's Three-Gorge reservoir was filled. The stability of these slopes during subsequent water level fluctuations is a public concern. For that reason, a series of transient seepage and slope stability analyses were performed to analyze the changes in the groundwater table in a landslide under the combined effects of reservoir water level drawdown and rainfall infiltration. The effects of gravel content in the slope soil on the groundwater regimes and the slope stability were also studied. The pore water pressures from these analyses were used for the stability analyses of the slope. The stability of the slope was found to decrease significantly when the reservoir level was lowered quickly during a rainstorm. This study also revealed that the infiltration rate is larger and the ground water level is higher in soil slopes with less gravel content, because the hydraulic conductivity of a soil with less gravel content is larger than that with higher gravel content when the soils are desaturated. It was concluded that the calculated factor of safety of the soil slope with less gravel content is smaller during rainfall. 21 refs., 1 tab., 8 figs.

  14. Water level-dependent morphological plasticity in Sagittaria montevidensis Cham. and Schl. (Alismataceae).

    Science.gov (United States)

    Demetrio, G R; Barbosa, M E A; Coelho, F F

    2014-08-01

    Aquatic plants are able to alter their morphology in response to environmental condition variation, such as water level fluctuations. The aim of this study was to evaluate the effect of water level on Sagittaria montevidensis morphology through measures of vegetative structures formed in drought and flood periods. We hypothesised that the plant height and the biomass of S. montevidensis leaves will increase during flood periods, while the biomass and diameter of petioles, and the basal plant area will increase during dry periods. We sampled a total amount of 270 individuals in nine sediment banks per visit, totalling 1080 plants. In order to compare plant morphology between dry and flood periods, we measured the water level in each bank and took the following variables for each plant: diameter, height and diameter of the biggest petiole. In order to compare biomass allocation between dry and flood periods, we sampled a total amount of 90 individuals in nine sediment banks per visit, totalling 360 plants. Plants were dried and weighed in the laboratory. All measured morphologic traits, as well as the biomass of leaf blades and petioles, were higher during flood periods, indicating that water level highly influences the morphology of S. montevidensis individuals. Our results suggest that these morphological responses allow survival and maintenance of S. montevidensis populations under environmental stress. These results can be linked to the invasive potential of S. montevidensis and sheds light on basic management practices that may be applied in the future. PMID:25627386

  15. Growth of floating-leaved and submerged plants in artificial co-cultured microcosms: morphological responses to various water fluctuation regimes

    International Nuclear Information System (INIS)

    Hydrocharis dubia can alternate between a rooted floating-leaved and a free-floating form, so given increasingly frequent precipitation extremes, it is not expected to be more negatively impacted by rapid water fluctuations than by gradual ones and may adapt water fluctuations by alteration of life forms. However, the opposite may be true for Nymphoides peltata, with only a rooted floating-leaved form. We designed an experiment combining six water depth treatments (constant shallow, constant deep, and two rapidly and two gradually fluctuating treatments) with three speciescombinations (N. peltata H. dubia, N. peltata Ceratophyllum demersum, and H. dubia C. demersum) to investigate plant responses to depth fluctuations and their co-cultured species. The total mass of N. peltata was considerably lower in the rapidly- than in the gradually-fluctuating treatments. However, total mass of H. dubia in the rapidly-fluctuating treatments was similar to or higher than in the gradually-fluctuating ones. Rapid fluctuations had a negative impact on the growth of C. demersum than gradual fluctuating. The floating-leaved species demonstrated divergent adaptive strategies to different water fluctuation patterns. In addition to expanding leaf blades, H. dubia can adapt to changing water depths by changing its life form. However, N. peltata, which mainly relies on morphological plasticity, such as petiole elongation, to adapt to water rise may reduce its abundance in communities subjected to increasingly frequent floods. The growth of submerged C. demersum, either co-occurring with H. dubia or with N. peltata, may be repressed by high flooding rates. (author)

  16. Seasonal fluctuations in the occurrence of Cladocera in the Mandovi-Zuari estuarine waters of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Devassy, V.P.

    1991-01-01

    Annual fluctuations in environmental features were noticeable particularly in the concentration of salinity and nutrients. The cladocerans showed a wide range of salinity tolerance and exhibited positive correlation with chlorophyll a(r = 0...

  17. Modelling Water Level Influence on Habitat Choice and Food Availability for Zostera Feeding Brent Geese Branta bernicla in Non-Tidal Areas

    DEFF Research Database (Denmark)

    Clausen, P.

    2000-01-01

    Brent geese Branta bernicla spring fattening around Agero, Denmark, alternate between feeding on saltmarshes and submerged Zostera beds in Limfjorden. It appeared from field observations that these alternations depended on the water level in Limfjorden. A model was developed to assess the impact of water level fluctuations on the habitat use. A second model was developed to estimate the impact of water level on Zostera availability. The first model was successful in demonstrating that fluctuations in water levels had considerable influence on habitat use by the brent geese, i.e. they fed on Zostera at low water levels and on saltmarshes during high water levels, particularly so in early spring, and that the switch between habitats occurred within a narrow water level span of ca 30 cm. The second model demonstrated that the switch between habitats could be explained by lowered availability of Zostera as water levels increased. By combining the output from the two models, differences between years could partly be explained by differences in Zostera availability in the early spring period (21 March - 25 April), whereas a more complicated situation was detected later in spring (26 April - 31 May). The models presented may be considered as tools in investigations of habitat use and carrying capacity of seagrass beds in non-tidal areas, where birds' access to feeding areas regularly may be hindered by high water levels.

  18. A multi-source satellite data approach for modelling Lake Turkana water level: calibration and validation using satellite altimetry data

    Directory of Open Access Journals (Sweden)

    N. M. Velpuri

    2012-01-01

    Full Text Available Lake Turkana is one of the largest desert lakes in the world and is characterized by high degrees of inter- and intra-annual fluctuations. The hydrology and water balance of this lake have not been well understood due to its remote location and unavailability of reliable ground truth datasets. Managing surface water resources is a great challenge in areas where in-situ data are either limited or unavailable. In this study, multi-source satellite-driven data such as satellite-based rainfall estimates, modelled runoff, evapotranspiration, and a digital elevation dataset were used to model Lake Turkana water levels from 1998 to 2009. Due to the unavailability of reliable lake level data, an approach is presented to calibrate and validate the water balance model of Lake Turkana using a composite lake level product of TOPEX/Poseidon, Jason-1, and ENVISAT satellite altimetry data. Model validation results showed that the satellite-driven water balance model can satisfactorily capture the patterns and seasonal variations of the Lake Turkana water level fluctuations with a Pearson's correlation coefficient of 0.90 and a Nash-Sutcliffe Coefficient of Efficiency (NSCE of 0.80 during the validation period (2004–2009. Model error estimates were within 10% of the natural variability of the lake. Our analysis indicated that fluctuations in Lake Turkana water levels are mainly driven by lake inflows and over-the-lake evaporation. Over-the-lake rainfall contributes only up to 30% of lake evaporative demand. During the modelling time period, Lake Turkana showed seasonal variations of 1–2 m. The lake level fluctuated in the range up to 4 m between the years 1998–2009. This study demonstrated the usefulness of satellite altimetry data to calibrate and validate the satellite-driven hydrological model for Lake Turkana without using any in-situ data. Furthermore, for Lake Turkana, we identified and outlined opportunities and challenges of using a calibrated satellite-driven water balance model for (i quantitative assessment of the impact of basin developmental activities on lake levels and for (ii forecasting lake level changes and their impact on fisheries. From this study, we suggest that globally available satellite altimetry data provide a unique opportunity for calibration and validation of hydrologic models in ungauged basins.

  19. A multi-source satellite data approach for modelling Lake Turkana water level: calibration and validation using satellite altimetry data

    Science.gov (United States)

    Velpuri, N. M.; Senay, G. B.; Asante, K. O.

    2012-01-01

    Lake Turkana is one of the largest desert lakes in the world and is characterized by high degrees of inter- and intra-annual fluctuations. The hydrology and water balance of this lake have not been well understood due to its remote location and unavailability of reliable ground truth datasets. Managing surface water resources is a great challenge in areas where in-situ data are either limited or unavailable. In this study, multi-source satellite-driven data such as satellite-based rainfall estimates, modelled runoff, evapotranspiration, and a digital elevation dataset were used to model Lake Turkana water levels from 1998 to 2009. Due to the unavailability of reliable lake level data, an approach is presented to calibrate and validate the water balance model of Lake Turkana using a composite lake level product of TOPEX/Poseidon, Jason-1, and ENVISAT satellite altimetry data. Model validation results showed that the satellite-driven water balance model can satisfactorily capture the patterns and seasonal variations of the Lake Turkana water level fluctuations with a Pearson's correlation coefficient of 0.90 and a Nash-Sutcliffe Coefficient of Efficiency (NSCE) of 0.80 during the validation period (2004-2009). Model error estimates were within 10% of the natural variability of the lake. Our analysis indicated that fluctuations in Lake Turkana water levels are mainly driven by lake inflows and over-the-lake evaporation. Over-the-lake rainfall contributes only up to 30% of lake evaporative demand. During the modelling time period, Lake Turkana showed seasonal variations of 1-2 m. The lake level fluctuated in the range up to 4 m between the years 1998-2009. This study demonstrated the usefulness of satellite altimetry data to calibrate and validate the satellite-driven hydrological model for Lake Turkana without using any in-situ data. Furthermore, for Lake Turkana, we identified and outlined opportunities and challenges of using a calibrated satellite-driven water balance model for (i) quantitative assessment of the impact of basin developmental activities on lake levels and for (ii) forecasting lake level changes and their impact on fisheries. From this study, we suggest that globally available satellite altimetry data provide a unique opportunity for calibration and validation of hydrologic models in ungauged basins.

  20. A multi-source satellite data approach for modelling Lake Turkana water level: Calibration and validation using satellite altimetry data

    Science.gov (United States)

    Velpuri, N.M.; Senay, G.B.; Asante, K.O.

    2012-01-01

    Lake Turkana is one of the largest desert lakes in the world and is characterized by high degrees of interand intra-annual fluctuations. The hydrology and water balance of this lake have not been well understood due to its remote location and unavailability of reliable ground truth datasets. Managing surface water resources is a great challenge in areas where in-situ data are either limited or unavailable. In this study, multi-source satellite-driven data such as satellite-based rainfall estimates, modelled runoff, evapotranspiration, and a digital elevation dataset were used to model Lake Turkana water levels from 1998 to 2009. Due to the unavailability of reliable lake level data, an approach is presented to calibrate and validate the water balance model of Lake Turkana using a composite lake level product of TOPEX/Poseidon, Jason-1, and ENVISAT satellite altimetry data. Model validation results showed that the satellitedriven water balance model can satisfactorily capture the patterns and seasonal variations of the Lake Turkana water level fluctuations with a Pearson's correlation coefficient of 0.90 and a Nash-Sutcliffe Coefficient of Efficiency (NSCE) of 0.80 during the validation period (2004-2009). Model error estimates were within 10% of the natural variability of the lake. Our analysis indicated that fluctuations in Lake Turkana water levels are mainly driven by lake inflows and over-the-lake evaporation. Over-the-lake rainfall contributes only up to 30% of lake evaporative demand. During the modelling time period, Lake Turkana showed seasonal variations of 1-2m. The lake level fluctuated in the range up to 4m between the years 1998-2009. This study demonstrated the usefulness of satellite altimetry data to calibrate and validate the satellite-driven hydrological model for Lake Turkana without using any in-situ data. Furthermore, for Lake Turkana, we identified and outlined opportunities and challenges of using a calibrated satellite-driven water balance model for (i) quantitative assessment of the impact of basin developmental activities on lake levels and for (ii) forecasting lake level changes and their impact on fisheries. From this study, we suggest that globally available satellite altimetry data provide a unique opportunity for calibration and validation of hydrologic models in ungauged basins. ?? Author(s) 2012.

  1. Ditch water levels manages for environmental aims: effects on field soil water regimes

    OpenAIRE

    Armstrong, A; Rose, S.

    1999-01-01

    The effects of ditch water management regimes on water tables are examined for two test sites in England, Halvergate in the Broads and Southlake Moor in the Somerset Levels and Moors Environmentally Sensitive Areas. It is observed that in some fields the effects of water management are only poorly transferred from the ditch to the field centre, especially where the hydraulic conductivity of the subsoil is small. Where there are large variations in the ditch water levels, reflecting the influe...

  2. Trace-level mercury removal from surface water

    International Nuclear Information System (INIS)

    Many sorbents have been developed for the removal of mercury and heavy metals from waters; however, most of the data published thus far do not address the removal of mercury to the target levels represented in this project. The application to which these sorbents are targeted for use is the removal of mercury from microgram-per-liter levels to low nanogram-per-liter levels. Sorbents with thiouronium, thiol, amine, sulfur, and proprietary functional groups were selected for these studies. Mercury was successfully removed from surface water via adsorption onto Ionac SR-4 and Mersorb resins to levels below the target goal of 12 ng/L in batch studies. A thiol-based resin performed the best, indicating that over 200,000 volumes of water could be treated with one volume of resin. The cost of the resin is approximately $0.24 per 1,000 gal of water

  3. Water-level change, High Plains aquifer, 1980 to 1995

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 1980 to 1995, in feet. The High Plains aquifer underlies...

  4. Water-level change, High Plains aquifer, 1995 to 2000

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 1995 to 2000, in feet. The High Plains aquifer underlies...

  5. Water level and vegetation change analysis at Stillwater Wildlife Refuge

    US Fish and Wildlife Service, Department of the Interior — The aim of the project summarized in this report was to determine the feasibility of detecting change in surface water levels and associated wetland biomass at the...

  6. Water-level change, High Plains aquifer, 2000 to 2005

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 2000 to 2005, in feet. The High Plains aquifer underlies...

  7. Water-level change, High Plains aquifer, 2005 to 2009

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 2005 to 2009, in feet. The High Plains aquifer underlies...

  8. Ground-water levels and tritium concentrations at the Maxey Flats low-level radioactive waste disposal site near Morehead, Kentucky, June 1984 to April 1989

    International Nuclear Information System (INIS)

    The Maxey Flats disposal site, Kentucky encompasses about 280 acres near the edge of a flat-topped ridge. The ridge is underlain by fractured shale and sandstone beds of the Nancy Member and the Farmers Member of the Borden Formation of Mississippian age. Groundwater flow in the strata beneath the site occurs through fractures, and flow patterns are difficult to delineate. The potentiometric surface also is difficult to delineate because several saturated and unsaturated zones are present in the rocks. Generally, ground-water levels in wells intersecting permeable fractures fluctuated seasonally and were lowest from December through June and highest from July through November. Water levels in the disposal trenches fluctuations less than those in wells, and for most trenches the fluctuations were less than 0.5 foot. From June 1984 to April 1989, tritium concentrations in groundwater ranged from 0 to 2,402,200 picocuries/ml. The greatest and most variable tritium concentrations were in wells along the northwest side of the site. The major conduit of groundwater flow from the trenches in the northwestern part of the site is a fractured sandstone bed that forms the base of most trenches. Elsewhere along the site perimeter, elevated levels of tritium were not detected in wells, and mean tritium were not detected in wells, and mean tritium concentrations showed little change between 1986 and 1988

  9. Typhoon and elevated radon level in a municipal water supply

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Cheng-Hsin [Nuclear Science and Development Center, National Tsing Hua Univ., Taiwan (China); Weng, Pao-Shan [Radiation Protection Association ROC, Taiwan (China)

    2000-05-01

    The Municipal Water Supply at Hsinchu City is a water treatment plant using poly- aluminum chloride (PAC) for coagulation and then followed by precipitation and filtration. Its capacity is 70,000 m{sup 3}/day. The raw water is drawn from the nearby river. Since the subject of interest is the radon level during typhoon season, the sampling period was from March to December 1999. Commercially available electret was used for water samples taken from the five ponds in the plant. This technique relies on the measurement of radon in air above a water sample enclosed in a sealed vessel. The concentration of airbone radon released from water was determined by means of the electret ion chamber. During the first sampling period there came two typhoons. One is called Magie during June 10-17, and the other called Sam during August 20-26. The first typhoon led to the radon level measured from the water samples as high as 705 Bq/m{sup 3}, while the second caused even higher radon level as high as 772 Bq/m{sup 3}. Similar results were obtained for the second sampling period after August till December 1999. For those measured without typhoon influence, the average radon was lower from the coagulation pond yet without coagulation process during March through August 1999. However, water samples taken from the pond after precipitation did not show similar results in radon level. (author)

  10. Typhoon and elevated radon level in a municipal water supply

    International Nuclear Information System (INIS)

    The Municipal Water Supply at Hsinchu City is a water treatment plant using poly- aluminum chloride (PAC) for coagulation and then followed by precipitation and filtration. Its capacity is 70,000 m3/day. The raw water is drawn from the nearby river. Since the subject of interest is the radon level during typhoon season, the sampling period was from March to December 1999. Commercially available electret was used for water samples taken from the five ponds in the plant. This technique relies on the measurement of radon in air above a water sample enclosed in a sealed vessel. The concentration of airbone radon released from water was determined by means of the electret ion chamber. During the first sampling period there came two typhoons. One is called Magie during June 10-17, and the other called Sam during August 20-26. The first typhoon led to the radon level measured from the water samples as high as 705 Bq/m3, while the second caused even higher radon level as high as 772 Bq/m3. Similar results were obtained for the second sampling period after August till December 1999. For those measured without typhoon influence, the average radon was lower from the coagulation pond yet without coagulation process during March through August 1999. However, water samples taken from the pond after precipitation did not show similar results in radon level. (author)

  11. Radium-226 levels in Italian drinking waters and foods

    International Nuclear Information System (INIS)

    Levels of 226Ra in Italian waters and foods were measured. Results were similar to those found in other countries, except for some mineral waters with 226Ra concentrations above 1 pCi/liter andup to 19 pCi/liter. No difinite correlation was found between the 226Ra concentrations measured and the high natural background radiation levels determined in central Italy in previous work

  12. Transient response of Salix cuttings to changing water level regimes

    Science.gov (United States)

    Gorla, L.; Signarbieux, C.; Turberg, P.; Buttler, A.; Perona, P.

    2015-03-01

    Sustainable water management requires an understanding of the effects of flow regulation on riparian ecomorphological processes. We investigated the transient response of Salix viminalis by examining the effect of water-level regimes on its above-ground and below-ground biomass. Four sets of Salix cuttings, three juveniles (in the first growing season) and one mature (1 year old), were planted and initially grown under the same water-level regime for 1 month. We imposed three different water-level regime treatments representing natural variability, a seasonal trend with no peaks, and minimal flow (characteristic of hydropower) consisting of a constant water level and natural flood peaks. We measured sap flux, stem water potential, photosynthesis, growth parameters, and final root architecture. The mature cuttings were not affected by water table dynamics, but the juveniles displayed causal relationships between the changing water regime, plant growth, and root distribution during a 2 month transient period. For example, a 50% drop in mean sap flux corresponded with a -1.5 Mpa decrease in leaf water potential during the first day after the water regime was changed. In agreement with published field observations, the cuttings concentrated their roots close to the mean water table of the corresponding treatment, allowing survival under altered conditions and resilience to successive stress events. Juvenile development was strongly impacted by the minimum flow regime, leading to more than 60% reduction of both above-ground and below-ground biomass, with respect to the other treatments. Hence, we suggest avoiding minimum flow regimes where Salix restoration is prioritized.

  13. Determination of Heavy Metal Levels in Various Industrial Waste Waters

    Directory of Open Access Journals (Sweden)

    Mustafa ?ahin Dündar

    2012-06-01

    Full Text Available Important part of the environmetal pollution consists of waste water and water pollution. The water polluted by anthropogenical, industrial, and agricultural originated sources are defined as waste waters which are the main pollution sources for reservoirs, rivers, lakes, and seas. In this work, waste waters of leather, textile, automotive side, and metal plating industries were used to determine the levels of Cu, Zn, Cr, Pb and Ni by using Flame Atomic Absorption Spectrometer. As a result, highest mean levels of copper in supernatants of plating and textile industries were observed as 377,18 ng ml-1, respectively 103 ng ml-1 lead and 963,6 ng ml-1 nickel in plating industry, 1068,2 ng ml-1 zinc and 14557,1 ng ml-1 chromium in plating and leather industries were determined.

  14. Relict faunal testimony for sea-level fluctuations off Myanmar (Burma)

    Digital Repository Service at National Institute of Oceanography (India)

    Panchang, R.; Nigam, R.; Raviprasad, G.V.; Rajagopalan, G.; Ray, D.K.; Hla, U Ko Yi

    2008-01-01

    in the geological past. Radiocarbon AMS dating of 7 select samples representing different depths revealed different ages at different depths. To derive a sea-level curve, the sea level was assigned to 17.5 m above the depth of finding the relict fauna as deciphered...

  15. A Feasibility Study to Lower Steam Generator Low Water Level Trip Setpoint to Reduce Unnecessary Scram Frequency for KORI 3,4 Plant

    International Nuclear Information System (INIS)

    The steam generator low water level trip setpoint of KORI NPP units 3 and 4(KNU 3 and 4), three-loop Westinghouse pressurized water reactor, is higher than that of OPR1000. In addition, steam generator downcomer water level in KNU 3 and 4 could fluctuate easily during a transient because of smaller downcomer water inventory, compared to the total water inventory in the steam generator. Due to these reasons, there is a higher possibility of unnecessary reactor trips caused by the steam generator low-low water level in KNU 3 and 4. Its operating history shows that most of reactor trips were caused by steam generator low-low level reactor trip signal. Such reactor trips, especially unnecessary ones, result in time and economic losses. In this paper, a feasibility study was performed to reduce unnecessary reactor trip by changing steam generator low-low water level reactor trip setpoint(SGLLRTS) for KNU 3 and 4

  16. Fluctuation of TeV to EeV Energy Muons and Induced Muon Showers in Water

    CERN Document Server

    Okumura, Y; Misaki, A

    2010-01-01

    By using the integral method in the muon propagation through water, we calculate the range fluctuation of high and ultra high energy muons. Many authors divide all radiative processes into two parts, namely, the continuous part and radiative part in their Monte Carlo simulation in order to consider the fluctuation in the both ranges and energies of the muons, while we treat all stochastic processes as exactly as possible, without the introduction of the continuous parts in all stochastic processes. The validity of our Monte Carlo method is checked by the corresponding analytical method which is methodologically independent on the Monte Carlo procedure. Accompanied cascade showers are generated by the direct electron pair production, bremsstrahlung and photo-nuclear interaction. These showers are calculated by the exact Monte Carlo Method in one dimensional way. We report survival probabilities, range distributions and examples of individual muon behavior.

  17. Water level regime in the Danube river and its river branches

    International Nuclear Information System (INIS)

    In the major part of the left side river branch system, fed through the intake structure at Dobrohost, relatively high level conditions are kept during the whole vegetation period. The flow in the upstream part (upstream line D) is comparable with the pre-dam stages for 4000 m3 s-1 in Bratislava and between lines E to D with the pre dam 3000 m3 s-1. The very downstream part of the system is controlled by the water level fluctuation in the Danube. The water level in the old Danube could be increased substantially by constructing a series of submerged hydraulic structures. An increase in water level of more than 1.5 m was achieved by the discharge of 400 m3 s-1 in the old Danube using preliminary design of structures situated in the reach between rkm 1817-1825. The guaranteed width of 90 m and depth of 2 m in the old Danube could be achieved at discharge rates of 1500 m3 s-1 or higher. The flow velocity is about 0.5 m s-1 or higher. The flow velocity is about 0.5 m s-1 in the reaches between the structures at discharge 400 m3 s-1 and about 1 m s-1 at discharge of m3 s-1. (authors). 8 figs., 1 map, 12 refs

  18. WATER-LEVEL MONITOR FOR BOREWELL AND WATER TANK BASED ON GSM

    Directory of Open Access Journals (Sweden)

    R.Ramani

    2012-10-01

    Full Text Available Now a days, home automation & remote control and monitoring systems have seen a rapid growth in terms of technology. Apparently there is no early warning system to monitor the tank water level and bore well water level when it has reached the critical level. In this paper we have provided water level monitoring in the tank as well as in the bore well. If the water level in a bore well drops below the threshold level for pumping its pump motor may get air locked or more burn out due to dry running. It is awkward for farmers to walk all the way to their fields at night just to switch the pump motor off. Besides, he may never get to identify the problem. This problem can be solved by using this GSM based system that will automatically make a call to the user mobile phone, when the water Level in the bore well drops threshold below or rises to the threshold level for pumping. The user can also remotely switch on or off the pump motor by sending a SMS from his mobile phone. The system is simple, reliable, portable and affordable. We proposed the work in which, Whenever water level in the tankdrops below the required level the system try to fill the tank by switching on the bore well motor to pump the water into the tank It is must to have enough water in the bore well to avoid the formation of air gap or empty running of bore well motor. High precision water level sensor is used to identify the reference water level to activate and deactivate the motor and system properly by interfacing the sensor devices into the well definedembedded system.

  19. Cadmium level: a comparative study in district Abbottabad's drinking water

    International Nuclear Information System (INIS)

    Abbottabad is a beautiful city of North West Frontier Province of Pakistan. A comparative study was conducted in order to see cadmium (Cd) level in drinking water of Abbottabad. 81 water samples were collected from wells, hand pumps, boring and municipal water distribution points. The samples were analyzed on atomic absorption spectrophotometer at Quaid-e-Azam University, Islamabad for the assessment of Cd level. The district Abbottabad was divided into five zones. Zone 1 consists of tehsil Havalian (16 samples), zone 2 consists of Qalanderabad to Mirpur area (16 samples), zone 3 consists of Nathiagali to Naryan area (21 samples), zone 4 consists of Sherwan to Shimla Hills area (13 samples), and zone 5 consists of Abbottabad City and Cantonment area (16 samples). The exact location of sampling points is shown in figure 1. Majority of the samples show Cd level within safe limits as described by World Health Organization (WHO) i.e. 3 micro g/l to 5 micro g/l. But in Zone 3 sample No.16,17, 18, 19 and zone 5 sample no 5 to 12 show high level of Cd. The results with respect to toxicity are dangerous to health. It is believed that this high level of Cd is due to underground mineral environment or due to seepage of domestic and Industrial waste water. Plumbing system of water supplies may also contribute to the increase of Cd level. According to municipal authorities in these areas the water supply (pipe line) has been laid before the creation of Pakistan (1947). Due to Poshe creation of Pakistan (1947). Due to Possible dangerous effect of Cd on health and environment, it is suggested that this higher level of Cd should be removed from water. We can use electrodialysis, revers osmosis or ion exchange processes consisting of resins (like Amberlite DP-1/ Amberlite IRC-718 for this purpose. (author)

  20. Monitoring water levels by integrating optical and synthetic aperture radar water masks with lidar DEMs

    Science.gov (United States)

    Hopkinson, C.; Brisco, B.; Patterson, S.

    2014-12-01

    The ability to map and monitor wetland and lake open water extent and levels across the landscape allows improved estimates of watershed water balance, surface storage and flood inundation. The study presents open water classifications over the wetland dominated Sheppard Slough watershed east of Calgary in western Canada using parallel temporal imagery captured from the RapidEye and RadarSat satellites throughout 2013, a year of widespread and costly flood inundation in this region. The optical and SAR-based temporal image stacks were integrated with a high-resolution lidar DEM in order to delineate regions of inundation on the DEM surface. GIS techniques were developed to extract lidar-derived water surface elevations and track the spatio-temporal variation in pond and lake water level across the watershed. Water bodies were assigned unique identifiers so that levels could be tracked and linked to their associated watershed channel reach. The procedure of optical image classification through to merging of individual water bodies into watershed channel topology and extracting reach water levels has been automated within python scripts. The presentation will describe: i) the procedures used; ii) a comparison of the SAR and optical classification and water level extraction results; iii) a discussion of the spatio-temporal variations in water level across the Sheppard Slough watershed; and iv) a commentary on how the approach could be implemented for web-based operational monitoring and as simulation initialisation inputs for flood inundation model studies.

  1. Ground-water discharge determined from measurements of evapotranspiration, other available hydrologic components, and shallow water-level changes, Oasis Valley, Nye County, Nevada

    International Nuclear Information System (INIS)

    Oasis Valley is an area of natural ground-water discharge within the Death Valley regional ground-water flow system of southern Nevada and adjacent California. Ground water discharging at Oasis Valley is replenished from inflow derived from an extensive recharge area that includes the northwestern part of the Nevada Test Site (NTS). Because nuclear testing has introduced radionuclides into the subsurface of the NTS, the U.S. Department of Energy currently is investigating the potential transport of these radionuclides by ground water flow. To better evaluate any potential risk associated with these test-generated contaminants, a number of studies were undertaken to accurately quantify discharge from areas downgradient in the regional ground-water flow system from the NTS. This report refines the estimate of ground-water discharge from Oasis Valley. Ground-water discharge from Oasis Valley was estimated by quantifying evapotranspiration (ET), estimating subsurface outflow, and compiling ground-water withdrawal data. ET was quantified by identifying areas of ongoing ground-water ET, delineating areas of ET defined on the basis of similarities in vegetation and soil-moisture conditions and computing ET rates for each of the delineated areas. A classification technique using spectral-reflectance characteristics determined from satellite imagery acquired in 1992 identified eight unique areas of ground-water ET. These areas encompass about 3,426 acres of sparsely to denselys about 3,426 acres of sparsely to densely vegetated grassland, shrubland, wetland, and open water. Annual ET rates in Oasis Valley were computed with energy-budget methods using micrometeorological data collected at five sites. ET rates range from 0.6 foot per year in a sparse, dry saltgrass environment to 3.1 feet per year in dense meadow vegetation. Mean annual ET from Oasis Valley is estimated to be about 7,800 acre-feet. Mean annual ground-water discharge by ET from Oasis Valley, determined by removing the annual local precipitation component of 0.5 foot, is estimated to be about 6,000 acre-feet. Annual subsurface outflow from Oasis Valley into the Amargosa Desert is estimated to be between 30 and 130 acre-feet. Estimates of total annual ground-water withdrawal from Oasis Valley by municipal and non-municipal users in 1996 and 1999 are 440 acre-feet and 210 acre-feet, respectively. Based on these values, natural annual ground-water discharge from Oasis Valley is about 6,100 acre-feet. Total annual discharge was 6,500 acre-feet in 1996 and 6,300 acre-feet in 1999. This quantity of natural ground-water discharge from Oasis Valley exceeds the previous estimate made in 1962 by a factor of about 2.5. Water levels were measured in Oasis Valley to gain additional insight into the ET process. In shallow wells, water levels showed annual fluctuations as large as 7 feet and daily fluctuations as large as 0.2 foot. These fluctuations may be attributed to water loss associated with evapotranspiration. In shallow wells affected by E T, annual minimum depths to water generally occurred in winter or early spring shortly after daily ET reached minimum rates. Annual maximum depths to water generally occurred in late summer or fall shortly after daily ET reached maximum rates. The magnitude of daily water-level fluctuations generally increased as ET increased and decreased as depth to water increased

  2. Environmental factors related to water level regulation - a comparative study in northern Finland

    International Nuclear Information System (INIS)

    The environmental conditions of the littoral zone were studied in the regulated Lake Ontojaervi and the unregulated Lake Lentua in northern Finland. The general aims of the study were to analyse the environmental factors related to water level regulation in the littoral zone and to produce information for assessing the effects of hydroelectric development in northern lakes. The study was basically carried out by comparing the littoral environments of the two study lakes. The most visible effects of water level regulation were related to the raised water level, which yielded erosion of sandy shores at the beginning of the regulation. Another effect of lake regulation was the altered fluctuation of the water level, which led to bottom instability and increased the size of the frozen and ice penetration zones. The effect of ice penetration was also easy to recognize on the shores of Lake Ontojaervi, where the surface sediment was frozen to a greater depth and across wider areas than in Lake Lentua. Below the freezing zone, the ice just pressed down on the sediment. The shores of Lake Ontojaervi were steeper than those of Lake Lentua, which affected the distribution of bottom types, with sandy bottoms being more common in Lake Lentua than in Lake Ontojaervi. The factors related to site exposure included effective fetch and the shape of the shoreline. The sedimentation level correlated only with the slope and was not predicted by the fetch or shape. The vertical reduction he fetch or shape. The vertical reduction of light was estimated on the basis of water colour. The main environmental factors from the two lakes were used in a discriminant analysis to predict the bottom type distribution of the littoral (r2 = 0.41). (orig.) 66 refs

  3. Subsidence at the Fairport Harbor Water Level Gauge

    Science.gov (United States)

    Conner, D. A.

    2014-12-01

    SUBSIDENCE AT THE FAIRPORT HARBOR WATER LEVEL GAUGE I will provide information on methods being used to monitor Lake Erie water levels and earth movement at Fairport Harbor, Ohio. Glacial Isostatic Adjustment (GIA) is responsible for vertical movement throughout the Great Lakes region. Fairport Harbor is also experiencing vertical movement due to salt mining, so the nearby water level gauge operated by the National Oceanic and Atmospheric Administration (NOAA) is affected by both GIA and mining. NOAA's National Geodetic Survey (NGS) defines and maintains the National Spatial Reference System (NSRS). The NSRS includes a network of permanently marked points; a consistent, accurate, and up-to-date national shoreline; a network of Continuously Operating Reference Stations (CORS) which supports three-dimensional positioning activities; and a set of accurate models describing dynamic, geophysical processes that affect spatial measurements. The NSRS provides the spatial reference foundation for transportation, mapping, charting and a multitude of scientific and engineering applications. Fundamental elements of geodetic infrastructure include GPS CORS (3-D), water level and tide gauges (height) and a system of vertical bench marks (height). When two or more of these elements converge they may provide an independent determination of position and vertical stability as is the case here at the Fairport Harbor water level gauge. Analysis of GPS, leveling and water level data reveal that this gauge is subsiding at about 2-3 mm/year, independent of the effects of GIA. Analysis of data from the nearby OHLA GPS CORS shows it subsiding at about 4 mm/yr, four times faster than expected due to GIA alone. A long history of salt mine activity in the area is known to geologists but it came as a surprise to other scientists.

  4. Sea-level fluctuations and coastal evolution in the state of Rio de Janeiro, southeastern Brazil

    Scientific Electronic Library Online (English)

    JOÃO WAGNER A., CASTRO; KENITIRO, SUGUIO; JOSÉ C.S., SEOANE; ALINE M. DA, CUNHA; FABIO F., DIAS.

    2014-06-01

    Full Text Available O presente trabalho tem como objetivo investigar as variações do nível relativo do mar e a evolução costeira durante o Holoceno no litoral do Estado do Rio de Janeiro, com base em indicadores geológicos e biológicos. Realizou-se levantamento altimétrico, execução de sondagens e datações ao 14C na pl [...] anície costeira e em afloramentos de rochas de praia. A partir dos dados obtidos, construiu-se uma curva do nível relativo do mar para o Holoceno. Pela primeira vez na costa brasileira foi identificado um recorde negativo do nível relativo do mar, envolvendo a transição final do Pleistoceno e início do Holoceno. Após a transição, iniciou-se um processo relativamente rápido de subida do nível do mar. Há aproximadamente 8.500 anos cal A.P., o nível marinho, encontrava-se a - 0.5 m abaixo do nível atual. O “zero” (nível médio atual) foi ultrapassado pela primeira vez no Holoceno há cerca de 7.500 anos A.P. Entre 5.500 - 4.500 cal anos A.P, o nível relativo do mar atingiu o primeiro máximo holocênico com altura máxima de +2.50 m acima do atual. A descida do nível relativo do mar subseqüente ao máximo transgressivo, levou à construção de terraços marinhos, resultando na progradação da linha de costa até o presente. A maioria dos resultados corroboram dados já obtidos em outros segmentos da costa atlântica da América do Sul. Resultados aqui apresentados são consistentes com pesquisas anteriores e ajudam refinar o registro do nível relativo do mar Holoceno na costa brasileira. Abstract in english The present paper aims to investigate the relative sea-level and the coastal evolution during the Holocene in the Rio de Janeiro coastline, based on geological and biological indicators. Using topographic survey, excavation and coring, and 14C dating of these coastal deposits and beachrocks outcrops [...] , we have reconstructed a sea-level curve for the Holocene. For the first time on the Brazilian coast it was identified a negative record of relative sea-level during Late Pleistocene and Early Holocene transition. After the transition, a relatively rapid increase of sea-level began. At approximately at 8500 cal yr BP, the sea-level was 0.5 m below the current level, was overtaken for the first time in the Holocene, at approximately 7500 cal yr BP. The maximum level of +2.5 m was reached between 4770 and 4490 cal yr BP. At the point of maximum transgression, the sea-level began a general behavior of lowering until the present. These results confirm other data already obtained elsewhere along the Atlantic coast of South America. The results of this study are consistent with previous researches and they help to refine the Holocene sea-level record along the Brazilian coast.

  5. Reticulate evolution and sea-level fluctuations together drove species diversification of slipper orchids (Paphiopedilum) in South-East Asia.

    Science.gov (United States)

    Guo, Yan-Yan; Luo, Yi-Bo; Liu, Zhong-Jian; Wang, Xiao-Quan

    2015-06-01

    South-East Asia covers four of the world's biodiversity hotspots, showing high species diversity and endemism. Owing to the successive expansion and contraction of distribution and the fragmentation by geographical barriers, the tropical flora greatly diversified in this region during the Tertiary, but the evolutionary tempo and mode of species diversity remain poorly investigated. Paphiopedilum, the largest genus of slipper orchids comprising nearly 100 species, is mainly distributed in South-East Asia, providing an ideal system for exploring how plant species diversity was shaped in this region. Here, we investigated the evolutionary history of this genus with eight cpDNA regions and four low-copy nuclear genes. Discordance between gene trees and network analysis indicates that reticulate evolution occurred in the genus. Ancestral area reconstruction suggests that vicariance and long-distance dispersal together led to its current distribution. Diversification rate variation was detected and strongly correlated with the species diversity in subg. Paphiopedilum (~80 species). The shift of speciation rate in subg. Paphiopedilum was coincident with sea-level fluctuations in the late Cenozoic, which could have provided ecological opportunities for speciation and created bridges or barriers for gene flow. Moreover, some other factors (e.g. sympatric distribution, incomplete reproductive barriers and clonal propagation) might also be advantageous for the formation and reproduction of hybrid species. In conclusion, our study suggests that the interplay of reticulate evolution and sea-level fluctuations has promoted the diversification of the genus Paphiopedilum and sheds light into the evolution of Orchidaceae and the historical processes of plant species diversification in South-East Asia. PMID:25847454

  6. Performance of broilers submitted to high CO2 levels during incubation combined with temperature fluctuations at late post-hatch

    Scientific Electronic Library Online (English)

    JIM, Fernandes; C, Bortoluzzi; AFG, Esser; JP, Contini; PB, Stokler; D, Faust.

    2014-09-01

    Full Text Available Incubation represents around 1/3 of the life cycle of broilers of modern strains; therefore, the appropriate management of this period is crucial to ensure the quality of the neonate. An experiment evaluated the effect of carbon dioxide concentrations during incubation on the live performance, heart [...] morphology, and differential leukocyte count in the blood of broilers submitted to fluctuating temperatures between 35 and 42 days of age. In total, 2,520 fertile eggs were distributed according to a completely randomized design with four CO2 concentrations (4,000; 6,000; 8,000 and 10,000 ppm) during the first ten days of incubation, after which all eggs were incubated at the same CO2 level (4,000 ppm). After hatching, male chicks were placed in the experimental broiler houses, and at 35 days of age, 25 birds from each level of CO2 were separated and placed in cages to study the effect of cyclic temperature variations up to 42 days of age on their live performance, heterophil:lymphocyte ratio, and heart morphology. At 42 days of age, blood was collected for hematology and two birds per replicate were sacrificed and evaluated for ascites score and heart and liver relative weights. Heart morphology was assessed by analyzing digital images. In this experiment, hypercapnia during incubation and fluctuating temperatures during the growout did not affect mortality, ascites score, heart and liver relative weights, or heart characteristics (p>0.05). However, heterophill:lymphocyte ratio increased (p

  7. Measurement of water potential in low-level waste management

    International Nuclear Information System (INIS)

    The measurement of soil water is important to the shallow land burial of low-level waste. Soil water flow is the principle mechanism of radionuclide transport, allows the establishment of stabilizing vegetation and also governs the dissolution and release rates of the waste. This report focuses on the measurement of soil water potential and provides an evaluation of several field instruments that are available for use to monitor waste burial sites located in arid region soils. The theoretical concept of water potential is introduced and its relationship to water content and soil water flow is discussed. Next, four major areas of soils research are presented in terms of their dependence on the water potential concept. There are four basic types of sensors used to measure soil water potential. These are: (1) tensiometers; (2) soil psychrometers; (3) electrical resistance blocks; and (4) heat dissipation probes. Tensiometers are designed to measure the soil water potential directly by measuring the soil water pressure. Monitoring efforts at burial sites require measurements of soil water over long time periods. They also require measurements at key locations such as waste-soil interfaces and within any barrier system installed. Electrical resistance blocks are well suited for these types of measurements. The measurement of soil water potential can be a difficult task. There are several sensors commercially available; however, each has its own limitations. It is important to carefully select the appropriate sensor for the job. The accuracy, range, calibration, and stability of the sensor must be carefully considered. This study suggests that for waste management activities, the choice of sensor will be the tensiometer for precise soil characterization studies and the electrical resistance block for long term monitoring programs

  8. Development of an in-vessel water level gauge for light water power reactors

    International Nuclear Information System (INIS)

    The in-vessel water level gauge, in principle, is based on the measurement of the temperature distribution on the surface of a long sheathed heater-pin which is partially immersed in water. Instead of adopting the measurement with many thermocouples, a binary-coded thermocouple array consisting of differential thermocouple array consisting of differential thermocouple trains (DTCTs) is settled on or in the sheath of a heater-pin to give a binary output related to the water level. Thus, this new-type of water level gauge was named BICOTH (Binary-Coded Thermocouple-array with Heater). After feasibility tests of the method with a prototype BICOTH, two types of in-vessel BICOTH were fabricated. The performance of each type was examined under the conditions of cold water and high-temperature, high-pressure water, and encouraging results were obtained. The principle and the test results are presented

  9. Holocene Sea-Level Fluctuations and Paleo-environmental changes in Maputo Bay, Mozambique, using stable isotopes

    Science.gov (United States)

    Martinez de Lecea, Ander; Green, Andrew; Wiles, Errol; Strachan, Kate; Cooper, Andrew

    2015-04-01

    Mozambique has been classified as a "hot-spot" for potential impacts derived from sea-level rise, yet there is little knowledge on past sea-level fluctuation in this part of the world. Further understanding of sea-level fluctuations in the region would be of great benefit. To this end a high resolution record of paleo-environmental changes in Maputo Bay, Mozambique, are determined. Stable isotope analyses (?13Corg; ?15N; ?18O) are conducted on the sediment organic matter and foraminifera Elphidium crispum from two cores, a 3.6 m long core collected at 5m below mean sea-level (m.s.l.) (Core V13) and a 6.2 m long core collected at 13.5m below m.s.l. (Core V40). Evolution of the region is informed through a seismic study and dating of cores is under-way using 14C analysis. The two cores analysed in this study showed evidence of catastrophic flooding events, as well as environmental changes. Core V13 represents a higher resolution of environmental changes, while core V40 shows a longer period, with the system changing from terrestrial dominated environment to marine, to terrestrially dominated once again before settling at the present system of marine dominated environment. The deepest layer of Core V13 is of marine origin with evidence of beachrock formation occurring, indicating a beach environment, while the top 190 cm indicate repeated alternation between marine and terrestrial environments, representing a contemporary highstand bay-head delta highly influenced by terrestrial input. This is further supported by the seismic interpretation. Enriched ?15N signatures from the terrestrial layers from the top 190 cm, could suggest the settling of early Europeans in the area (~1,544 AD). Core V40's deepest layer is of terrestrial origin, and terminates abruptly in marine sand, most likely due to the sudden, catastrophic collapse of the dune barrier following sea-level rise. Comparisons of preliminary results with existing studies suggests that this core covers a time period of almost 10 ka yr BP and we anticipate that the 14C results will confirm this. Finally, there is evidence of vegetation change in Maputo Bay through time; core V40's terrestrial strata have a strong C3 plant (original forest) signature, while the terrestrial strata from core V13 have a C4 plant (current crops) signature. Our results suggest that Maputo Bay represents an extremely dynamic environment for at least the last 9 ka yr BP, where sudden, catastrophic events can occur, and provide important insights into the environmental evolution of the region.

  10. Return Levels of Northern Great Plains Snow Water Equivalents

    Science.gov (United States)

    Grundstein, Andrew J.; Lu, Qiqi; Lund, Robert

    2006-07-01

    This paper estimates return levels of extreme snow water equivalents (SWE) in the northern Great Plains region, containing North and South Dakota, Iowa, Minnesota, and Nebraska. The return levels are estimated from extreme-value methods using a new hybrid SWE dataset that improves the spatial resolution of existing data in the area. A novel aspect of the methods is the use of standard error margins to spatially smooth the estimated SWE return levels computed on individual grid cells. The end product is a reliable return-level estimate that controls for uncertainties in the raw observations. The methods should prove useful in analyses of other geographical regions.

  11. Analysis of the cross-correlation between seismicity and water level in the Aswan area (Egypt from 1982 to 2010

    Directory of Open Access Journals (Sweden)

    L. Telesca

    2012-07-01

    Full Text Available In this study the correlation between the monthly fluctuations of the water level of the Aswan High Dam and monthly number of earthquakes from 1982 to 2010, which occurred in the surrounding area, was investigated. Our findings reveal that significant correlation is present during the period 1982–1993 between water level and shallow seismicity (depth less than 15 km. The deep seismicity (depth larger than 15 km is significantly correlated with the water level between January and April 1989. The time lag of the significant maximal cross-correlation varies from 2–8~months for the shallow seismicity, while it is around 7–8 months for the deep seismicity. These values of the time lags could be in favour of the presence of two distinct triggering mechanisms: one due to pore pressure diffusion and the other due to fracture compaction (undrained response.

  12. Ground Water Modeling Of Arsenic Contaminated Sandy Aquifer With Response To Transient River Levels, Mekong Delta, Cambodia.

    Science.gov (United States)

    Ganguly, S.; Polizzotto, M.; Sampson, M.; Fendor, S.; Benner, S.

    2006-12-01

    The sandy aquifer of Mekong River Delta in Cambodia is a primary drinking water source and contains elevated concentrations of dissolved arsenic (15-1300?g/L), a common problem of Southeast Asia. Both hydraulic heads and dissolved arsenic concentrations vary temporally with respect to transient hydraulic head of the Mekong River, suggesting that groundwater flow plays a potentially important role in arsenic mobilization/transportation. The river fluctuates annually 5 to 8 m, with the highest levels in mid-September due to upstream monsoonal rains and Himalayan snowmelt and the lowest levels in mid-May to early June. The hydraulic gradient between the river and adjacent aquifer changes direction biannually; when the river is rising the gradient is from the river to the aquifer, when the river is falling the gradient is from the aquifer towards the river. In contrast, wetlands overlying the aquifer exhibit time varying head change of 2.5 to 3m annually due to local rain from late September to early October and an apparent limited hydraulic connection to aquifer. Numerical modeling (using MODFLOW) is able to reproduce the aquifer head distribution by transiently altering the river boundary condition, supporting the hypothesis that the temporal variations in observed hydraulic head are primarily driven by the seasonal river fluctuations. The modeling also supports the conclusion that the observed dampening of water level fluctuations in the distal part of the study area is due to increasing distance from the Mekong River.

  13. Ensemble approach for projections of return periods of extreme water levels in Estonian waters

    Science.gov (United States)

    Eelsalu, Maris; Soomere, Tarmo; Pindsoo, Katri; Lagemaa, Priidik

    2014-12-01

    The contribution of various drivers to the water level in the eastern Baltic Sea and the presence of outliers in the time series of observed and hindcast water level lead to large spreading of projections of future extreme water levels. We explore the options for using an ensemble of projections to more reliably evaluate return periods of extreme water levels. An example of such an ensemble is constructed by means of fitting several sets of block maxima (annual maxima and stormy season maxima) with a Generalised Extreme Value, Gumbel and Weibull distribution. The ensemble involves projections based on two data sets (resolution of 6 h and 1 h) hindcast by the Rossby Centre Ocean model (RCO; Swedish Meteorological and Hydrological Institute) and observed data from four representative sites along the Estonian coast. The observed data are transferred into the grid cells of the RCO model using the HIROMB model and a linear regression. For coastal segments where the observations represent the offshore water level well, the overall appearance of the ensembles signals that the errors of single projections are randomly distributed and that the median of the ensemble provides a sensible projection. For locations where the observed water level involves local effects (e.g. wave set-up) the block maxima are split into clearly separated populations. The resulting ensemble consists of two distinct clusters, the difference between which can be interpreted as a measure of the impact of local features on the water level observations.

  14. AUTOMATED WATER LEVEL MEASUREMENTS IN SMALL-DIAMETER AQUIFER TUBES

    Energy Technology Data Exchange (ETDEWEB)

    PETERSEN SW; EDRINGTON RS; MAHOOD RO; VANMIDDLESWORTH PE

    2011-01-14

    Groundwater contaminated with hexavalent chromium, strontium-90, and uranium discharges into the Columbia River along approximately 16 km (10 mi) of the shoreline. Various treatment systems have and will continue to be implemented to eliminate the impact of Hanford Site contamination to the river. To optimize the various remediation strategies, it is important to understand interactions between groundwater and the surface water of the Columbia River. An automated system to record water levels in aquifer sampling tubes installed in the hyporheic zone was designed and tested to (1) gain a more complete understanding of groundwater/river water interactions based on gaining and losing conditions ofthe Columbia River, (2) record and interpret data for consistent and defensible groundwater/surface water conceptual models that may be used to better predict subsurface contaminant fate and transport, and (3) evaluate the hydrodynamic influence of extraction wells in an expanded pump-and-treat system to optimize the treatment system. A system to measure water levels in small-diameter aquifer tubes was designed and tested in the laboratory and field. The system was configured to allow manual measurements to periodically calibrate the instrument and to permit aquifer tube sampling without removing the transducer tube. Manual measurements were collected with an e-tape designed and fabricated especially for this test. Results indicate that the transducer system accurately records groundwater levels in aquifer tubes. These data are being used to refine the conceptual and numeric models to better understand interactions in the hyporheic zone of the Columbia River and the adjacent river water and groundwater, and changes in hydrochemistry relative to groundwater flux as river water recharges the aquifer and then drains back out in response to changes in the river level.

  15. Fluctuations of Phytoplankton Community in the Coastal Waters of Caspian Sea in 2006

    OpenAIRE

    Siamak Bagheri; Mashhor Mansor; Marzieh Makaremi; Jalil Sabkara; Maznah, W. O. W.; Alireza Mirzajani; Khodaparast, Seyed H.; Hossein Negarestan; Azemat Ghandi; Akbar Khalilpour

    2011-01-01

    Problem statement: The Caspian Sea ecosystem has been suffered with many problems since 1980s. Aanthropogenic pollution from heavy metals, hydrocarbons, pesticides, changes in the quantity of nutrient inputs by rivers, are significant threats to biodiversity and biological resources such as plankton structure in the Caspian Sea. According to the significant of phytoplankton community in marine system. The state of the fluctuations of phytoplankton communities of the southwestern Caspian Sea w...

  16. Politics of innovation in multi-level water governance systems

    Science.gov (United States)

    Daniell, Katherine A.; Coombes, Peter J.; White, Ian

    2014-11-01

    Innovations are being proposed in many countries in order to support change towards more sustainable and water secure futures. However, the extent to which they can be implemented is subject to complex politics and powerful coalitions across multi-level governance systems and scales of interest. Exactly how innovation uptake can be best facilitated or blocked in these complex systems is thus a matter of important practical and research interest in water cycle management. From intervention research studies in Australia, China and Bulgaria, this paper seeks to describe and analyse the behind-the-scenes struggles and coalition-building that occurs between water utility providers, private companies, experts, communities and all levels of government in an effort to support or block specific innovations. The research findings suggest that in order to ensure successful passage of the proposed innovations, champions for it are required from at least two administrative levels, including one with innovation implementation capacity, as part of a larger supportive coalition. Higher governance levels can play an important enabling role in facilitating the passage of certain types of innovations that may be in competition with currently entrenched systems of water management. Due to a range of natural biases, experts on certain innovations and disciplines may form part of supporting or blocking coalitions but their evaluations of worth for water system sustainability and security are likely to be subject to competing claims based on different values and expertise, so may not necessarily be of use in resolving questions of "best courses of action". This remains a political values-based decision to be negotiated through the receiving multi-level water governance system.

  17. The response of mire vegetation to water level drawdown

    Science.gov (United States)

    Kurki, Kirsi; Laine, Jukka; Vasander, Harri; Tuittila, Eeva-Stiina

    2010-05-01

    Mires have a significant role in climate change mitigation due to their enormous carbon storage and due to the fluxes of greenhouse gases between ecosystem and the atmosphere. Mire vegetation is controlled by ecohydrology, climate and by the competition of plants on light and nutrients. The water logged conditions create a challenging environment for both vascular plants and bryophytes; therefore majority of plants growing in these habitats are highly specialized. Global warming is predicted to affect mire vegetation indirectly through increased evapotranspiration leading to decreased water table levels down to 14-22 centimeters. Water level drawdown is likely to affect the vegetation composition and consequently the ecosystem functioning of mires. Previous studies covering the first years following water table level drawdown have shown that vascular plants benefit from a lower water table and hollow-specific Sphagnum species suffer. In addition to changes in plant abundances the diversity of plant communities decreases. The lawn and hollow communities of Sphagna and sedges are found to be the most sensitive plant groups. It has been shown that surveys on vegetation changes can have different results depending on the time scale. The short and long term responses are likely vary in heterogenous mire vegetation; therefore predictions can be done more reliably with longer surveys. We applied BACI (before-after-control-impact) experimental approach to study the responses of different functional mire plant groups to water level drawdown. There are 3 control plots, 3 treatment plots with moderate water level drawdown and 3 plots drained for forestry 40 years ago as a reference. The plots are located in meso-, oligo- and ombrotrophic sites in Lakkasuo (Orivesi, Finland). The vegetation was surveyed from permanent sampling points before ditching in 2000 and during the years 2001-2003 and 2009. The data was analyzed with NMDS (PC-Ord) and DCA (CANOCO). Overall results show that the control and treatment plots were similar before the treatment which is crucial in studies conducted with BACI- experimental design. The vegetation composition in the varied between the years also in the control plots following variation in weather conditions, i.e., growing season temperature and precipitation. The year 2003 stood out with lowest water table levels and with highest coverage of the evergreen vascular plants in all plots. By 2009 there was a dramatic decrease in sedge species cover. There seems to be more changes in bryophyte cover in mesotrophic sites than in ombrotrophic ones. Especially lawn-specific Sphagnum responded to water level drawdown. To quantify the impact of water level drawdown for different plant groups we used Principal Response Curves (CANOCO). Results show that all plant groups have a different short and long term response to water level drawdown. The first three years after ditching appeared to be a disturbance state. Only after that the vegetation started to adapt to the lowered water table conditions.

  18. Secular Global Changes in different Tidal High Water, Low Water and Range levels

    Science.gov (United States)

    Mawdsley, Robert; Haigh, Ivan; Wells, Neil

    2015-04-01

    Tides exert a major control on the coastal zone by influencing high sea levels and coastal flooding, navigation, sediment dynamics and ecology. Therefore, any changes to tides have wide ranging and important implications. In this paper, we uniquely assess secular changes in 15 regularly used tidal levels (five high water, five low water and five tidal ranges), which have direct practical applications. Using sea level data from 220 tide gauge sites, we found changes have occurred in all analysed tidal levels in many parts of the world. For the tidal levels assessed, between 36% and 63% of sites had trends significantly different (at 95% confidence level) from zero. At certain locations, the magnitude of the trends in tidal levels were similar to trends in mean sea level over the last century, with observed changes in tidal range and high water levels of over 5mm/yr and 2mm/yr respectively. More positive than negative trends were observed in tidal ranges and high water levels, and vice versa for low water levels. However we found no significant correlation between trends in mean sea level and any tidal levels. Spatially coherent trends were observed in some regions, including the north-east Pacific, German Bight and Australasia, and we also found that differences in trends occur between different tidal levels. This implies that analysing different tidal levels is important. Because changes in the tide are widespread and of similar magnitude to mean sea level rise at a number sites, changes in tides should be considered in coastal risk assessments.

  19. In vivo detection of fluctuating brain steroid levels in zebra finches.

    Science.gov (United States)

    Ikeda, Maaya; Rensel, Michelle A; Schlinger, Barney A; Remage-Healey, Luke

    2014-12-01

    This protocol describes a method for the in vivo measurement of steroid hormones in brain circuits of the zebra finch. A guide cannula is surgically implanted into the skull, microdilysate is collected through a microdialysis probe that is inserted into the cannula, and steroid concentrations in the microdialysate are determined using the enzyme-linked immunosorbent assay (ELISA). In some cases, the steroids measured are derived locally (e.g., neural estrogens in males), whereas in other cases, the steroids measured reflect systemic circulating levels and/or central conversion (e.g., the primary androgen testosterone and the primary glucocorticoid corticosterone). A reverse-microdialysis ("retrodialysis") method that can be used to deliver pharmacological agents into the brain to influence local steroid neurochemistry as well as behavior is also discussed. PMID:25342066

  20. Dynamics of a Landau-Zener non-dissipative system with fluctuating energy levels

    Science.gov (United States)

    Fai, L. C.; Diffo, J. T.; Ateuafack, M. E.; Tchoffo, M.; Fouokeng, G. C.

    2014-12-01

    This paper considers a Landau-Zener (two-level) system influenced by a three-dimensional Gaussian and non-Gaussian coloured noise and finds a general form of the time dependent diabatic quantum bit (qubit) flip transition probabilities in the fast, intermediate and slow noise limits. The qubit flip probability is observed to mimic (for low-frequencies noise) that of the standard LZ problem. The qubit flip probability is also observed to be the measure of quantum coherence of states. The transition probability is observed to be tailored by non-Gaussian low-frequency noise and otherwise by Gaussian low-frequency coloured noise. Intermediate and fast noise limits are observed to alter the memory of the system in time and found to improve and control quantum information processing.

  1. Experimental detection of radiative energy signal from a supercharged marine boiler and simulation on its application in control of drum water level

    International Nuclear Information System (INIS)

    This paper describes a study on the application of a flame detecting system installed in a marine supercharged boiler. Flame images captured from experiments show that fluctuation of the flame in the supercharged boiler is intensive than that in stationary power plant boilers. Radiative Energy Signal (RES) is obtained from experiments by the flame detecting system, and it is shown that RES varies approximately linearly with the oil consumption rate and the heat absorption rate in the riser. Then, an instantaneous heat absorption rate is deduced from the real time RES by a linear equation, and a control strategy for the water level in drum by RES is proposed, in which the real time RES is used to control the flow rate of feed water in advance. Simulation results show that the fluctuating amplitude of the water level can be reduced significantly by introducing RES, and this control strategy has a great potential to improve the control quality of drum water level in the supercharged boiler. - Highlights: ? We install a flame detecting system on a marine boiler to monitor furnace combustion. ? We use flame image processing technology to analyze the boiler combustion behavior. ? A control strategy is proposed as introducing RES into the feed water control system. ? Simulation shows the drum water level overcome fluctuations by inducing RES. ? Experiments state this strategy and detecting method for improving combustion efficiency.

  2. Statistical characterization of fluctuations of a laser beam transmitted through a random air-water interface: new results from a laboratory experiment

    Science.gov (United States)

    Majumdar, Arun K.; Land, Phillip; Siegenthaler, John

    2014-10-01

    New results for characterizing laser intensity fluctuation statistics of a laser beam transmitted through a random air-water interface relevant to underwater communications are presented. A laboratory watertank experiment is described to investigate the beam wandering effects of the transmitted beam. Preliminary results from the experiment provide information about histograms of the probability density functions of intensity fluctuations for different wind speeds measured by a CMOS camera for the transmitted beam. Angular displacements of the centroids of the fluctuating laser beam generates the beam wander effects. This research develops a probabilistic model for optical propagation at the random air-water interface for a transmission case under different wind speed conditions. Preliminary results for bit-error-rate (BER) estimates as a function of fade margin for an on-off keying (OOK) optical communication through the air-water interface are presented for a communication system where a random air-water interface is a part of the communication channel.

  3. Water table fluctuation in aquifers overlying a semi-impervious layer due to transient recharge from a circular basin

    Science.gov (United States)

    Ilias, Teloglou S.; Thomas, Zissis S.; Andreas, Panagopoulos C.

    2008-01-01

    SummaryAn analytical solution of a linearised form of Boussinesq equation is presented in this paper to describe the water table fluctuation in unconfined aquifers overlying a semi-impervious layer in response to transient recharge. This solution does not require the common assumption of an impervious formation underlain the unconfined aquifer. On the contrary, it shows that even when the hydraulic conductivity of the semi-impervious layer is several orders of magnitude less than the aquifer hydraulic conductivity, downward leakage can be important and can lead to large overestimations of water table heights if it is ignored. The rate of recharge is considered to decrease exponentially with time during a single cycle of recharge while two cycles of time varying recharge are approximated by continuous elements described by Nth degree polynomials. Numerical solution of the non-linear Boussinesq equation was implemented to validate the applied linearisation.

  4. Comparison Between Water Level and Precipitation in Rio Negro Basin

    Science.gov (United States)

    Figliuolo, G. C.; Santos Da Silva, J.; Calmant, S.; Seyler, F.; Correia, F.; Oliveira, R. J.

    2013-12-01

    The Amazon Basin holds a lot of difficulties for providing data that enable regional researching works, because of its large extension and for having areas, whose access is very difficult. Remote sensing data presents an excellent way for monitoring the Amazon Basin and collecting data for researches. This current study aims matching radar altimetry data from the JASON-2, with the rainfall data from the TRMM satellite in order to analyze the relation between the water level and the precipitation in two different points along the Rio Negro Basin. After data analysis, it was possible noting a difference on the responding process for both regions. Whilst at the NEGRO_089_03 station (located in the city of São Gabriel da Cachoeira) the graphic of precipitation and water level were very similar, in NEGRO_063 station (located in the city of Manaus) the graphic showed a two month discrepancy due to the difference of the river's bottom size in both regions, at NEGRO_089_03's area for having a smaller river and the water level rises faster, whereas in NEGRO_063 the water level takes about two months to respond to precipitation.

  5. CAN FLUORIDATION AFFECT WATER LEAD LEVELS AND LEAD NEUROTOXICITY?

    Science.gov (United States)

    Recent reports have attempted to show that certain approaches to fluoridating potable water is linked to increased levels of lead(II) in the blood. We examine these claims in light of the established science and critically evaluate their significance. The completeness of nexafluo...

  6. Global secular changes in different tidal high water, low water and range levels

    Science.gov (United States)

    Mawdsley, Robert J.; Haigh, Ivan D.; Wells, Neil C.

    2015-02-01

    Tides exert a major control on the coastal zone by influencing high sea levels and coastal flooding, navigation, sediment dynamics, and ecology. Therefore, any changes to tides have wide ranging and important implications. In this paper, we uniquely assess secular changes in 15 regularly used tidal levels (five high water, five low water and five tidal ranges), which have direct practical applications. Using sea level data from 220 tide gauge sites, we found changes have occured in all analyzed tidal levels in many parts of the world. For the tidal levels assessed, between 36% and 63% of sites had trends significantly different (at 95% confidence level) from zero. At certain locations, the magnitude of the trends in tidal levels were similar to trends in mean sea level over the last century, with observed changes in tidal range and high water levels of over 5 mm yr-1 and 2 mm yr-1, respectively. More positive than negative trends were observed in tidal ranges and high water levels, and vice versa for low water levels. However we found no significant correlation between trends in mean sea level (MSL) and any tidal levels. Spatially coherent trends were observed in some regions, including the north-east Pacific, German Bight and Australasia, and we also found that differences in trends occur between different tidal levels. This implies that analyzing different tidal levels is important. Because changes in the tide are widespread and of similar magnitude to MSL rise at a number sites, changes in tides should be considered in coastal risk assessments.

  7. Radioactivity levels in waters and sediments from Van Lake / Turkey

    International Nuclear Information System (INIS)

    It is well known that natural radionuclides can be effective as tracers for the different processes controlling the distribution of elements dissolved and particulate phases in aquatic systems. Significant radiation doses to man can potentially occur following radioactive contamination of water bodies such as rivers, lakes and reservoirs. In the long term, radioactivity in the water body can remain at significant levels as a result of secondary contamination processes. The Van Lake is located at Eastern part of Turkey and it is largest Lake of Turkey. The purpose of this study is to measure natural radioactivity in the waters and sediments taken from along to shore of Van Lake. Total of 19 surface coast lake waters and 18 sediments samples were collected from Van Lake in dry season in 2005, in the first part of this Project. In surface lake water samples, pH, mV and conductivity values were measured and alkalinity content was determined titrimetrically. The uranium concentrations in the lake water samples were measured using uranium analyzer. Radioactivities related to gross radium isotopes, gross-? and gross-? radioactivity levels in the surface water were determined. Gross radium isotopes were separated using the barium sulphate co-precipitation method and then the radioactivity of gross radium isotopes was measured by ZnS(Ag) alpha scintillation counter. The correlation among measured parameters for water samples and concentrations of uranium and gross radium isotopes are also discussed. Natural radioactivity in the sediments was also determined by gamma spectrometer. The field and laboratory studies on this project are carried out

  8. An analysis of the water-level monitoring system for a boiling-water reactor

    International Nuclear Information System (INIS)

    The water-level instrumentation system is very important to the overall safety of a BWR. This system is being monitored by the Safety Parameter Display System (SPDS) that is being installed in Georgia Power Company's Plant Hatch. One of the most significant functions of the SPDS is the comparison of redundant instrument readings and formation of the best estimate of each parameter from those readings which are consistent. When comparing water-level instrument readings, it is necessary to correct the individual readings for differences between current and calibration conditions as well as for differences between calibration conditions for the multiple instruments. This paper documents the examination of the water-level instrumentation system at Plant Hatch and presents the development of the equations that were used to determine the differences between indicated and actual water levels. (author)

  9. Response to an oral calcium load in nephrolithiasis patients with fluctuating parathyroid hormone and ionized calcium levels

    Scientific Electronic Library Online (English)

    S.A., Gomes; A., Lage; M., Lazaretti-Castro; J.G.H., Vieira; I.P., Heilberg.

    2004-09-01

    Full Text Available the response to an oral calcium load test was assessed in 17 hypercalciuric nephrolithiasis patients who presented elevated parathyroid hormone (PTH) irrespective of the ionized calcium (sCa2+) levels. Blood samples were collected at baseline (0 min) and at 60 and 180 min after 1 g calcium load for [...] serum PTH, total calcium, sCa2+, and 1.25(OH)2D3 determinations. According to the sCa2+ level at baseline, patients were classified as normocalcemic (N = 9) or hypercalcemic (N = 8). Six healthy subjects were also evaluated as controls. Bone mineral density was reduced in 14/17 patients. In the normocalcemic group, mean PTH levels at 0, 60 and 180 min (95 ± 76, 56 ± 40, 57 ± 45 pg/ml, respectively) did not differ from the hypercalcemic group (130 ± 75, 68 ± 35, 80 ± 33 pg/ml) but were significantly higher compared to healthy subjects despite a similar elevation in sCa2+ after 60 and 180 min vs baseline in all 3 groups. Mean total calcium and 1.25(OH)2D3 were similar in the 3 groups. Additionally, we observed that 5 of 9 normocalcemic patients presented a significantly higher concentration-time curve for serum PTH (AUC0',60',180') than the other 4 patients and the healthy subjects, suggesting a primary parathyroid dysfunction. These data suggest that the individual response to an oral calcium load test may be a valuable dynamic tool to disclose a subtle primary hyperparathyroidism in patients with high PTH and fluctuating sCa2+ levels, avoiding repeated measurements of both parameters.

  10. Response to an oral calcium load in nephrolithiasis patients with fluctuating parathyroid hormone and ionized calcium levels

    Directory of Open Access Journals (Sweden)

    S.A. Gomes

    2004-09-01

    Full Text Available the response to an oral calcium load test was assessed in 17 hypercalciuric nephrolithiasis patients who presented elevated parathyroid hormone (PTH irrespective of the ionized calcium (sCa2+ levels. Blood samples were collected at baseline (0 min and at 60 and 180 min after 1 g calcium load for serum PTH, total calcium, sCa2+, and 1.25(OH2D3 determinations. According to the sCa2+ level at baseline, patients were classified as normocalcemic (N = 9 or hypercalcemic (N = 8. Six healthy subjects were also evaluated as controls. Bone mineral density was reduced in 14/17 patients. In the normocalcemic group, mean PTH levels at 0, 60 and 180 min (95 ± 76, 56 ± 40, 57 ± 45 pg/ml, respectively did not differ from the hypercalcemic group (130 ± 75, 68 ± 35, 80 ± 33 pg/ml but were significantly higher compared to healthy subjects despite a similar elevation in sCa2+ after 60 and 180 min vs baseline in all 3 groups. Mean total calcium and 1.25(OH2D3 were similar in the 3 groups. Additionally, we observed that 5 of 9 normocalcemic patients presented a significantly higher concentration-time curve for serum PTH (AUC0',60',180' than the other 4 patients and the healthy subjects, suggesting a primary parathyroid dysfunction. These data suggest that the individual response to an oral calcium load test may be a valuable dynamic tool to disclose a subtle primary hyperparathyroidism in patients with high PTH and fluctuating sCa2+ levels, avoiding repeated measurements of both parameters.

  11. Response to an oral calcium load in nephrolithiasis patients with fluctuating parathyroid hormone and ionized calcium levels

    Directory of Open Access Journals (Sweden)

    Gomes S.A.

    2004-01-01

    Full Text Available the response to an oral calcium load test was assessed in 17 hypercalciuric nephrolithiasis patients who presented elevated parathyroid hormone (PTH irrespective of the ionized calcium (sCa2+ levels. Blood samples were collected at baseline (0 min and at 60 and 180 min after 1 g calcium load for serum PTH, total calcium, sCa2+, and 1.25(OH2D3 determinations. According to the sCa2+ level at baseline, patients were classified as normocalcemic (N = 9 or hypercalcemic (N = 8. Six healthy subjects were also evaluated as controls. Bone mineral density was reduced in 14/17 patients. In the normocalcemic group, mean PTH levels at 0, 60 and 180 min (95 ± 76, 56 ± 40, 57 ± 45 pg/ml, respectively did not differ from the hypercalcemic group (130 ± 75, 68 ± 35, 80 ± 33 pg/ml but were significantly higher compared to healthy subjects despite a similar elevation in sCa2+ after 60 and 180 min vs baseline in all 3 groups. Mean total calcium and 1.25(OH2D3 were similar in the 3 groups. Additionally, we observed that 5 of 9 normocalcemic patients presented a significantly higher concentration-time curve for serum PTH (AUC0',60',180' than the other 4 patients and the healthy subjects, suggesting a primary parathyroid dysfunction. These data suggest that the individual response to an oral calcium load test may be a valuable dynamic tool to disclose a subtle primary hyperparathyroidism in patients with high PTH and fluctuating sCa2+ levels, avoiding repeated measurements of both parameters.

  12. Identification of flow regimes for steam-water two phase flow using differential pressure fluctuations

    International Nuclear Information System (INIS)

    Based on wavelet analysis, a novel method of steam-liquid two phase flow regimes on-line fuzzy identification is presented. The pipeline pressure drop is adopted for measurement signal along the heated test section, its fluctuation characteristic has been proceeded two-stage decompose based on third-stratum Daubechies wavelet, and a criterion of identifying the flow regimes is proposed in the term of root-mean-square deviation of two-stage fine coefficient obtained in the wavelet analysis. The research results show that the method is feasible for the flow regimes identification of typical bubble and slug flow. (authors)

  13. Fluctuations of the Caspian Sea level as an indicator of global climatic changes - using data from radiocarbon dating of sediments

    International Nuclear Information System (INIS)

    Because of the large area of the basin water, the level of the Caspian Sea reflects the global change of climate of the Northern hemisphere. In order to reconstruct the paleoclimatic situation, samples were taken from ancient salt marshes, depressions and bars which form when the sea level has fallen significantly. Mollusc shells, peat, carbonates and organic matter were used for 14C dating. The data obtained demonstrate the relationship between the sea level and climatic changes. During cooling the sea level rises and vice versa. This relates to the long-period (13,000 y) as well as to the short-period (2,000-2,500 y) and to secular changes of the climate. (author)

  14. Quadratic controller syntheses for the steam generator water level

    International Nuclear Information System (INIS)

    The steam generator water level, (SGWL), control problem in the pressurized water reactor of a nuclear power plant is considered from robust control techniques point of view. The plant is a time-varying system with a non minimum phase behavior and an unstable open-loop response. The time-varying nature of the plant due to change in operating power is taken into account by including slowly time-varying uncertainty in the model. A linear Time-Invariant, (LTI) guaranteed cost quadratic stabilizing controller is designed in order to address some of the particular issues arising for such a control problem. (author)

  15. Quality Level of Bottled Drinking Water Consumed in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Ashraf E.M. Khater

    2014-01-01

    Full Text Available The quality of drinking water is a universal health concern and access to safe water is a fundamental human right. Many national and international organizations set certain parameters and levels for Bottled Drinking Water (BDW to ensure their quality. The present work aims to analyze the quality of various brands of BDW used in Saudi Arabia and to compare the quality levels to the BDW standards. One hundred and twenty six samples of 54 different BDW brands were collected from the Saudi market. The quality level parameters were analyzed using portable meters for pH, EC and TDS; spectrophotometer, HACH DR-2800 for F, SO4 and NO3; Inductively Coupled Plasma (ICP Mass Spectrometer (MS and atomic emission spectrometer (AES for elemental analysis. To evaluate the quality level parameters of BDW, the parameters were classified as following: (1 Parameters and substances affect the quality of BDW (pH, EC, TDS, HCO3, F, NO3 and SO4. (2 Macronutrients (Ca, K, Mg and Na. (3 Micronutrients-trace elements (Co, Cr, Cu, Fe, Mo, Se and Zn, (4 Potentially essential elements that have some beneficial health effects (B, Mn, Ni and V and (5 Toxic elements (Al, As, Cd, Hg, Pb, Th and U using Inductively coupled plasma-mass spectrometry, ICP-MS. The concentrations of the detected elements were compared with the Golf and international standard like World Health Organization.

  16. Analytical approach for predicting fresh water discharge in an estuary based on tidal water level observations

    Directory of Open Access Journals (Sweden)

    H. Cai

    2014-06-01

    Full Text Available As the tidal wave propagates into an estuary, the tidally averaged water level tends to rise in landward direction due to the density difference between saline and fresh water and the asymmetry of the friction. The effect of friction on the residual slope is even more remarkable when accounting for fresh water discharge. In this study, we investigate the influence of river discharge on tidal wave propagation in the Yangtze estuary with specific attention to residual water level slope. This is done by using a one-dimensional analytical model for tidal hydrodynamics accounting for the residual water level. We demonstrate the importance of the residual slope on tidal dynamics and use it to improve the prediction of the tidal propagation in estuaries (i.e., tidal damping, velocity amplitude, wave celerity and phase lag, especially when the influence of river discharge is significant. Finally, we develop a new inverse analytical approach for estimating fresh water discharge on the basis of tidal water level observations along the estuary, which can be used as a tool to obtain information on the river discharge that is otherwise difficult to measure in the tidal region.

  17. Predicting the residual aluminum level in water treatment process

    Directory of Open Access Journals (Sweden)

    J. Tomperi

    2012-06-01

    Full Text Available In water treatment processes, aluminum salts are widely used as coagulation chemical. High dose of aluminum has been proved to be at least a minor health risk and some evidence points out that aluminum could increase the risk of Alzheimer's disease thus it is important to minimize the amount of residual aluminum in drinking water and water used at food industry. In this study, the data of a water treatment plant (WTP was analyzed and the residual aluminum in drinking water was predicted using Multiple Linear Regression (MLR and Artificial Neural Network (ANN models. The purpose was to find out which variables affect the amount of residual aluminum and create simple and reliable prediction models which can be used in an early warning system (EWS. Accuracy of ANN and MLR models were compared. The new nonlinear scaling method based on generalized norms and skewness was used to scale all measurement variables to range [?2...+2] before data-analysis and modeling. The effect of data pre-processing was studied by comparing prediction results to ones achieved in an earlier study. Results showed that it is possible to predict the baseline level of residual aluminum in drinking water with a simple model. Variables that affected the most the amount of residual aluminum were among others: raw water temperature, raw water KMnO4 and PAC / KMnO4-ratio. The accuracies of MLR and ANN models were found to be almost equal. Study also showed that data pre-processing affects to the final prediction result.

  18. Effects of Water Levels on Productivity of Canada Geese in the Northern Flathead Valley, 1985 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Daniel

    1986-04-01

    Operation of Hungry Horse Dam on the South Fork Flathead River causes sporadic water level fluctuations along the main stem Flathead River. Changes in chronology of seasonal water level fluctuations and substantial habitat losses have occurred as a result of construction and operation of Kerr Dam, which regulates Flathead Lake. These fluctuations may impact goose populations through flooding and erosion of nesting and brood-rearing habitats, and increased susceptibility of nests and young to predation. The number, location, and success of goose nests were determined through pair surveys and nest searches. Our 1985 pair count data indicated that 95 to 143 nests may have been present. Hatching success for 1985 nests (55%) was low compared to long-term averages for the region. Predation was the predominant cause of ground nest failure (25 nests); we documented 2 nest failures due to flooding. The maximum gosling count in the study area for 1985 was 197. Six key brood-rearing areas were identified. Most (80%) sites were located in the herbaceous or pasture cover type and the riparian bench landform. Analysis of aerial photographs taken prior to construction of Kerr Dam documented the loss of 1859 acres of habitat along the north shore of Flathead Lake. Losses were attributed to inundation and to continuing erosion due to operation of Kerr Dam. Lake and river water level regimes were compared with the chronology of important periods in the nesting cycle. Low lake levels in May and early June coincide with the breed-rearing period. Mudflats are heavily used by broods, but their effect on survival must still be documented. Preliminary recommendations to protect and enhance Canada goose habitat and production are being developed.

  19. Water-level and fuel-failure external monitoring

    International Nuclear Information System (INIS)

    One of the lessons from the TMI-2 incident is the need for better real-time operator knowledge of water level and coolant density in the core and downcomer. Although several level-measurement instrument systems internal to the pressure vessel have been developed, each has certain inherent limitations. Some performance capabilities are lacking also in a neutron detection method that uses shielded counters located external to the pressure vessel. Judging from the experience gained in prior level-gauge developments and relying on two decades of data accumulated from fast neutron hodoscopes, a gamma-ray detection method ought to provide better liquid level and density detection, with the added capability of on-line fuel-failure monitoring. Most important, the monitoring of high-energy gamma rays could provide information specific to the properties of direct interest

  20. Investigation of natural radioactivity levels in water around Kadugli, Sudan

    International Nuclear Information System (INIS)

    Surface water from Miri Lake and groundwater from around Kadugli (West-Central Sudan) obtained by means of hand-pumps was analysed for 238U, 226Ra, 222Rn, and 232Th activity concentrations. The surface water showed very low levels of radionuclide concentrations: -1 for 238U, 226Ra, 222Rn, and 232Th, respectively. Groundwater revealed a significant amount of natural radioactivity (16.1-1720, 7.7-14.3, 3000-139,000, -1) respectively. The overall annual effective dose was below the WHO reference dose level of 0.1 mSv yr-1 except in one groundwater sample with an associated dose of 0.7 mSv yr-1

  1. The Water Level Fall of Lake Megali Prespa (N Greece): an Indicator of Regional Water Stress Driven by Climate Change and Amplified by Water Extraction?

    Science.gov (United States)

    van der Schriek, Tim; Giannakopoulos, Christos

    2014-05-01

    The Mediterranean stands out globally due to its sensitivity to (future) climate change, with future projections predicting an increase in excessive drought events and declining rainfall. Regional freshwater ecosystems are particularly threatened: precipitation decreases, while extreme droughts increase and human impacts intensify (e.g. water extraction, drainage, pollution and dam-building). Many Mediterranean lake-wetland systems have shrunk or disappeared over the past two decades. Protecting the remaining systems is extremely important for supporting global biodiversity and for ensuring sustainable water availability. This protection should be based on a clear understanding of lake-wetland hydrological responses to natural and human-induced changes, which is currently lacking in many parts of the Mediterranean. The interconnected Prespa-Ohrid Lake system is a global hotspot of biodiversity and endemism. The unprecedented fall in water level (~8m) of Lake Megali Prespa threatens this system, but causes remain debated. Modelling suggests that the S Balkan will experience rainfall and runoff decreases of ~30% by 2050. However, projections revealing the potential impact of these changes on future lake level are unavailable as lake regime is not understood. A further drop in lake level may have serious consequences. The Prespa Lakes contribute ~25% of the total inflow into Lake Ohrid through underground karst channels; falling lake levels decrease this discharge. Lake Ohrid, in turn, feeds the Drim River. This entire catchment may therefore be affected by falling lake levels; its water resources are of great importance for Greece, Albania, FYROM and Montenegro (e.g. tourism, agriculture, hydro-energy, urban & industrial use). This new work proves that annual water level fluctuations of Lake Megali Prespa are predominantly related to precipitation during the first 7 months (Oct-Apr) of the hydrological year (Oct-Sep). Lake level is very sensitive to regional and Mediterranean wet-dry events during this period. There are robust indications for a link between lake level and the North Atlantic Oscillation, which is known to strongly influence Mediterranean winter precipitation. Hydro-climatic records show a complicated picture, but tentatively support the conclusion that the unprecedented lake level fall is principally related to climate change. The available fluvial discharge record and most existing snowfall records show statistically significant decreases in annual averages. Annual rainfall only shows a statistically significant decrease of the 25th percentile; 7-month rainfall (Oct-Apr) additionally shows a statistically significant but non-robust decrease of the mean. The modest amount of water extraction (annually: ~14*103m3, ~0.004% of total lake volume) exerts a progressive and significant impact on lake level over the longer term, accounting for ~25% of the observed fall. Lake level lowering ends when lake-surface area shrinkage has led to a decrease in lake-surface evaporation that is equivalent to the amount of water extracted. The adjustment of lake level to stable extraction rates requires two to three decades. This work aims to steer adaptation and mitigation strategies by informing on lake response under different climate change and extraction scenarios. Lake protection is a cost effective solution for supporting global biodiversity and for providing sustainable water resources.

  2. Evaluation of statistical properties of free-surface fluctuation on a high-speed water jet using laser refraction technique

    International Nuclear Information System (INIS)

    Free-surface fluctuation on a high-speed water jet has been evaluated using a laser beam refraction technique. This technique employs two pulse laser diodes and one high-speed optic detector. By detecting the two dimensional (2D) trajectory of laser beams refracted at free surface, the local streamwise slope-angle fluctuation at two measuring locations 1.27 mm apart on a jet free surface can be evaluated. The experiments are conducted for several locations along the jet center axis within the range of average velocity up to 10 m/s. The wave speed is evaluated from dominant time lag of cross-correlation coefficient for individual wave period, which is divided from time-series slope-angle data according to the zero-up-crossing method. The shape of waves is also calculated by integrating the free-surface slope angle. The wavelength and wave height are evaluated from the individual waveform. The steepness of free surface wave takes a maximum at a certain distance from nozzle exit for U ? 8 m/s. This suggests that the initial amplification of wave results in a wave breaking on the jet free surface for these velocity conditions. (author)

  3. Water level changes for Lake Turkana and climate variability during the African Humid Period

    Science.gov (United States)

    Bloszies, C.; Forman, S. L.; Wright, D. K.

    2013-12-01

    The chronology of East African paleoclimate suggests the transition through the African Humid Period (AHP) at ca. 15 to 5 ka was a binary shift from wet conditions in the Late Pleistocene to current aridity. Previous studies indicate that water levels for Lake Turkana for the AHP were stable at ~88 to 98 m above current level with outflow into the White Nile Basin. This study of relict beaches around Lake Turkana indicates surprisingly >50 m variability in water level between 14 and 4 ka. The elevation of past water level is constrained by barometric and GPS-based altimetry of relict beaches and age control by 14C dating of associated mollusks and OSL dating of quartz grains from surrounding littoral and sublittoral deposits. We also include well provenanced lake level data from prior studies to constrain more fully the timing and height of water level fluctuations in the Late Quaternary. Additionally, previous studies indicate that peak water levels may be regionally amplified by increased precipitation causing overflow into the Lake Turkana Basin from the adjacent Suguta and Chew Bahir basins, particularly during high stands at ca. >8.5 ka and at 6.3 ka. Our analysis of the Lake Turkana strandplain reveals that water level may have varied by × 60 m, potentially reaching the outlet elevation at ca.11.3, 10.3, 9.0, 6.3 and 5.1 ka. There are other possible high stands at ca. 13.0, 8.4, 7.8 and 7.0 ka with limited elevational and age constraints; it is unknown if these lake stands reached the outlet elevation. Evidence from relict strand plains indicate that lake level was probably below 20 m since ca. 4.5 ka, though there were two noticeable high stands up to >12 to 18 m at ca. 830 years ago and wax (?Dwax) from lakes Tanganika and Victoria and associated sea surface temperature (SST) records from the Indian and the Atlantic oceans. A brief (<500 yr) high stand up to at least 50 m at ca. 7 ka appears to be coincident with warm postglacial SSTs in the western Indian Ocean and thus may reflect a strengthened East African Monsoon, though some precipitation was probably derived from Atlantic sources as well. Similarly, the brief high stand (< 400 yr) at 6.3 ka, possibly up to 100 m, is associated with warming across the Indian Ocean and equator-ward compression of the ITCZ reflecting a strengthened East African Monsoon. This high stand also may be in response to elevated SSTs in the eastern Atlantic Ocean and associated intensification of West African Monsoon. A final high stand up to at least 95 m at ca. 5.0 to 5.5 ka appears to have occurred with sustained moisture influx into East Africa from Atlantic-derived sources, coincident with warming in the western Indian Ocean. The AHP for Lake Turkana is characterized by extreme water level variability, rather than a sustained water level, with a final and rapid fall in lake level between 5.0 and 4.5 ka associated with increasing aridity.

  4. Steam Pressurizer test and water level measurement performance test

    International Nuclear Information System (INIS)

    The reports discuss steam high pressure chamber test and water level measurement system performance test. In the report, the necessity and the methodology of test is described. The test loop and small scale steam chamber are designed. The validation for the design is conducted. Muliti-channel(200 or more) high-speed data acquisition system is required and chosen. The achievement of 1st year and 2nd year plan are presented

  5. Visualization of Flow in Pressurizer Spray Line Piping and Estimation of Thermal Stress Fluctuation Caused by Swaying of Water Surface

    Science.gov (United States)

    Oumaya, Toru; Nakamura, Akira; Onojima, Daisuke; Takenaka, Nobuyuki

    The pressurizer spray line of PWR plants cools reactor coolant by injecting water into pressurizer. Since the continuous spray flow rate during commercial operation of the plant is considered insufficient to fill the pipe completely, there is a concern that a water surface exists in the pipe and may periodically sway. In order to identify the flow regimes in spray line piping and assess their impact on pipe structure, a flow visualization experiment was conducted. In the experiment, air was used substituted for steam to simulate the gas phase of the pressurizer, and the flow instability causing swaying without condensation was investigated. With a full-scale mock-up made of acrylic, flow under room temperature and atmospheric pressure conditions was visualized, and possible flow regimes were identified based on the results of the experiment. Three representative patterns of swaying of water surface were assumed, and the range of thermal stress fluctuation, when the surface swayed instantaneously, was calculated. With the three patterns of swaying assumed based on the visualization experiment, it was confirmed that the thermal stress amplitude would not exceed the fatigue endurance limit prescribed in the Japanese Design and Construction Code.

  6. Peatland pines as a proxy for water table fluctuations: disentangling tree growth, hydrology and possible human influence.

    Science.gov (United States)

    Smiljani?, Marko; Seo, Jeong-Wook; Läänelaid, Alar; van der Maaten-Theunissen, Marieke; Staji?, Branko; Wilmking, Martin

    2014-12-01

    Dendrochronological investigations of Scots pine (Pinus sylvestris L.) growing on Männikjärve peatland in central Estonia showed that annual tree growth of peatland pines can be used as a proxy for past variations of water table levels. Reconstruction of past water table levels can help us to better understand the dynamics of various ecological processes in peatlands, e.g. the formation of vegetation patterns or carbon and nitrogen cycling. Männikjärve bog has one of the longest water table records in the boreal zone, continuously monitored since 1956. Common uncertainties encountered while working with peatland trees (e.g. narrow, missing and wedging rings) were in our case exacerbated with difficulties related to the instability of the relationship between tree growth and peatland environment. We hypothesized that the instable relationship was mainly due to a significant change of the limiting factor, i.e. the rise of the water table level due to human activity. To test our hypothesis we had to use several novel methods of tree-ring chronology analysis as well as to test explicitly whether undetected missing rings biased our results. Since the hypothesis that the instable relationship between tree growth and environment was caused by a change in limiting factor could not be rejected, we proceeded to find possible significant changes of past water table levels using structural analysis of the tree-ring chronologies. Our main conclusions were that peatland pines can be proxies to water table levels and that there were several shifting periods of high and low water table levels in the past 200 years. PMID:25217744

  7. Wave-induced mass transport affects daily Escherichia coli fluctuations in nearshore water

    Science.gov (United States)

    Ge, Zhongfu; Whitman, Richard L.; Nevers, Meredith B.; Phanikumar, Mantha S.

    2012-01-01

    Characterization of diel variability of fecal indicator bacteria concentration in nearshore waters is of particular importance for development of water sampling standards and protection of public health. Significant nighttime increase in Escherichia coli (E. coli) concentration in beach water, previously observed at marine sites, has also been identified in summer 2000 from fixed locations in waist- and knee-deep waters at Chicago 63rd Street Beach, an embayed, tideless, freshwater beach with low currents at night (approximately 0.015 m s–1). A theoretical model using wave-induced mass transport velocity for advection was developed to assess the contribution of surface waves to the observed nighttime E. coli replenishment in the nearshore water. Using average wave conditions for the summer season of year 2000, the model predicted an amount of E. coli transported from water of intermediate depth, where sediment resuspension occurred intermittently, that would be sufficient to have elevated E. coli concentration in the surf and swash zones as observed. The nighttime replenishment of E. coli in the surf and swash zones revealed here is an important phase in the cycle of diel variations of E. coli concentration in nearshore water. According to previous findings in Ge et al. (Environ. Sci. Technol. 2010, 44, 6731–6737), enhanced current circulation in the embayment during the day tends to displace and deposit material offshore, which partially sets up the system by the early evening for a new period of nighttime onshore movement. This wave-induced mass transport effect, although facilitating a significant base supply of material shoreward, can be perturbed or significantly influenced by high currents (orders of magnitude larger than a typical wave-induced mass transport velocity), current-induced turbulence, and tidal forcing.

  8. Modelling the impact of climate change on groundwater in the UK. Stage 2 report, using an unsaturated zone transfer function to model groundwater level fluctuations

    OpenAIRE

    O Dochartaigh, B. E.

    2001-01-01

    This report describes work carried out as part of the second stage of the joint BGS-CEH project “Modelling the impact of climate change on groundwater in the UK”. The work described in the report involved testing and developing a simple approach to the reproduction of historical groundwater level fluctuations. The technique makes use of an unsaturated zone transfer function to represent delayed recharge. The model was used to replicate long-term groundwater level records fr...

  9. Holocene lake level fluctuations of a small alpine lake in the Qilian Mountains, NW China: a comparison of chironomid, ostracod, pollen and geochemistry data.

    Science.gov (United States)

    Mischke, S.; Herzschuh, U.

    2003-04-01

    A core of 14 m length was drilled in a small alpine lake in the Qilian Mountains, NW China. The lake Luanhaizi has a drainage area of about 30 km2 and is situated at an altitude of 3200 m which represents the altitude of the present regional upper timberline. Due to the small size of the open-basin lake (surface area about 1 km2) and the sharply outlined catchment area the lake is regarded as a very sensitively and rapidly responding ecosystem. Analyses of ostracod shells, head capsules of larval chironomids and pollen and spores were conducted and the organic and carbonate content (LOI), element concentrations and magnetic susceptibility of core samples determined. Ostracod taxa mainly comprise Candona candida, C. neglecta, C. rawsoni, Cyclocypris ovum, Cypridopsis vidua, Fabaeformiscandona caudata, F. danielopoli, F. hyalina, Herpetocypris chevreuxi, Heterocypris salina, Ilyocypris cf. bradyi, I. echinata, I. lacustris and Limnocythere inopinata. They may be used to distinguish periods of low lake levels corresponding to a dense cover of aquatic plants at the lake bottom from stages of higher lake levels and a corresponding decrease in macrophytes at the core site. Chironomid taxa belonging to Chironomus, Cladopelma, Glyptotendipes, Micropsectra, Paratanytarsus, Polypedilum, Psectrocladius and Tanytarsus further provide information on variations in benthic oxygen availability and lake level fluctuations. Several units of the core show high abundances of pollen and spores of higher aquatic and wetland plants and fungi (Cyperaceae, Hippuris, Myriophyllum and Glomus) indicating low lake levels. In contrast, algae such as Botryococcus, Pediastrum and Tetraedron were regarded to reflect higher water levels. Typha angustifolia-type, Typha latifolia, Alisma and Potamogeton were recorded in low abundances as well. The organic content of core samples averages 6 % displaying four alternating stages of distinct minima and maxima. Lowest values of about 1 % occur at the core base whereas the organic content rises to 16 % at maximum near the top. The carbonate content displays a similar pattern with strong shifts ranging from 3 to 31%. The results of the investigation of the sediment core from the alpine lake in the Qilian Mountains were presented and the validity of single proxies with respect to lake level changes discussed.

  10. Response of the Apodi-Mossoró estuary-incised valley system (NE Brazil) to sea-level fluctuations

    OpenAIRE

    Helenice Vital; Lima Furtado, Samia F.; Moab Praxedes Gomes

    2010-01-01

    This study focuses on the Quaternary sea level changes in the Apodi-Mossoró Estuary and adjacent shelf, Northeastern Brazil, based on the analysis of high-resolution seismic profiles, integrated with echosounder, SRTM and satellite image data. We use these data to develop a relative stratigraphy. An incised-valley extending from the Apodi-Mossoró Estuary onto the shelf dominates the investigated area. In very shallow waters (down to 10 m depth) the channel lies mainly in a NW-SE direction, ...

  11. CRC technology of nozzle. Water level instrumentation nozzle

    International Nuclear Information System (INIS)

    Inconel 182 is used for welding joint material between Reactor Pressure Vessel (RPV) nozzle and nozzle safe-end in nuclear power plants (Nozzle indicates an only water level instrumentation nozzle in this paper). Corrosion Resistant Cladding (CRC) is the method which is welded a Stress Corrosion Cracking (SCC) resistant material cladding to the welding joint portion. Still more CRC technology is applied to the internal surface of nozzle made of Inconel 600 which is known to have SCC sensitivity. This technology prevents from the SCC initiation of material. In actual work after cutting nozzle safe-end, small-sized welding machine is put into the nozzle whose inside diameter is about 50 mm. These nozzles are installed at the three different levels of RPV. In case of the lowest nozzle, which placed near the core, it is necessary to build the shielding blocks outside RPV, and keep the reactor water in the vessel to protect workers' radiation exposure. Therefore a water-proof working box is installed around nozzle area inside RPV to perform CRC in dry environment. This technology had been applied to a couple of operating plants. (author)

  12. Primary collector wall local temperature fluctuations in the area of water-steam phase boundary

    International Nuclear Information System (INIS)

    A limited number of temperature sensors could be installed at the primary collector surface in the area of water - steam phase boundary. The surface temperatures as well WWER 440 steam generator process data were measured and stored for a long time and off-line evaluated. Selected results are presented in the paper. (orig.)

  13. An Indirect Adaptive Controller to Regulate UTSG Water Level in Pressurized Water Nuclear Reactor

    Directory of Open Access Journals (Sweden)

    Djamel Boukhetala

    2012-01-01

    Full Text Available Stabilizing water level of the Steam Generator (SG in nuclear power plant is a very important problem since its parameters vary with operating conditions and dynamics of the system is very different according to the power levels and changes as time goes on. Therefore, it is an intractable as well as challenging task to improve the water level control system of the SG. In this study, a new framework for building an adaptive Minimum Variance controller for stabilizing water-level of SG is proposed. We use the recursive least squares algorithm to identify the Input/Output models. Minimum Variance Control (MVC law is also used to develop the adaptation controller. Emphasis is put on the evaluation of the parameter identification in order to avoid instabilities because of disturbances or insufficient excitations. This is especially of importance when the adaptive control is carried out in closed loop systems and without additional test signals. The algorithm so proposed is simulated and applied to the water level control in the U-Tube Steam Generating unit (UTSG used for electricity generation. It is shown through application to a nonlinear model of steam generators that the proposed controller has good performance.

  14. Constraints on the amplitude of late Pliocene eustatic sea-level fluctuations: New evidence from the New Zealand shallow-marine sediment record

    Science.gov (United States)

    Naish, Tim

    1997-12-01

    Since 2.5 Ma, global eustatic sea-level fluctuations have driven recurrent transgressions and regressions of the shoreline across the world's continental shelves. The resulting shallow-marine sedimentary record is cyclothemic, each cyclothem corresponding to a single Milankovitch climatic or sea-level cycle. Wanganui Basin, New Zealand, contains one of the most complete late Neogene shallow-marine stratigraphic records in the world in the form of a continuous cyclostratigraphy representing every 41 k.y. and 100 k.y. sea-level cycle since oxygen isotope stage 104 (ca. 2.6 Ma). A eustatic sea-level curve is derived for oxygen isotope stages 100 74, from high-resolution faunal paleobathymetric, subsidence, and stratigraphic analyses of 12 superposed, shallow-marine cyclothems in the Rangitikei River section, Wanganui Basin. Between 2.6 and 2.0 Ma minimum amplitudes of eustatic sea-level fluctuations ranged from 110 ± 20 m (stages 100 99) to 25 ± 10 m (stages 76 75). These independently derived fluctuations are ˜20% larger than previous estimates, and imply greater climatic variability during the onset of major Northern Hemisphere ice ages.

  15. Optimum Water Level for Spent Fuel Pool using MCNP Code

    International Nuclear Information System (INIS)

    TRIGA reactor (RTP) has been operated for more than 30 years. Some of the part of the reactor become degraded by the time. Sooner or later, all these part either will be changed with a new part and proceed with upgrading plan or the reactor itself will be decommissioned. By that time, spent fuel pool (SFP) need to be ready to keep all the fuel from the core. The conceptual design of the SFP has been established. This paper will determine optimum water level to avoid any radiation hazard expose to the workers during managing the fuel later. This determination will use MCNP computer code. (author)

  16. [Bacterial fluctuations in the recreational waters of the Mar del Plata area].

    Science.gov (United States)

    Cabezalí, C B; Darlan, L A; Pezzani, S; Serra, S

    1986-01-01

    In the period comprised between 1981 and 1983, a study was carried out in relation with the bacteriological quality of the sea water used for recreational purposes. Beaches are situated along 35 km of coast, including Mar Chiquita and Gral. Pueyrredón Departments. The principal pollution focus is the city of Mar del Plata which, like many other big cities, overturns its industrial, rainy and urban sewer liquids to the sea, with no previous treatment, in most of the cases. The effluent open sewer, situated in the north suburban district, drives into the sea the content of three maximum sewers that recollect domiciliary branches. To determine quali and quantitatively heterotrophic aerobic mesophilic, psicrophilic, marine and E. coli bacteria, water samples were taken at 0.30 m depth, behind the shoal, in each of the 17 determined stations (Figure 1), and an enumeration of colonies in agar plate was carried out in duplicate. E. coli was used as indicator of fecal contamination and served to establish the quality of the water used in bath and other recreational functions. The quantification was done by recounts in plates or membrane filter methods, in duplicate, with previous revivification. Serology of strains isolated from marine medium by polyvalent sera was done. Independently of the recount obtained, the distribution of serological groups was rather uniform along all the coast. Colony-forming units (CFU) did not exceed values of 240/100 ml, except in the beach situated at 0.5 km of the effluent, which always gave values above those accepted internationally for bathing waters or other recreational uses (Figure 2).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3685386

  17. Establishing solar water disinfection as a water treatment method at household level

    Directory of Open Access Journals (Sweden)

    Regula Meierhofer

    2006-12-01

    Full Text Available 1.1 billion People worldwide do not have access to safe drinking water and therefore are exposed to a high risk for diarrhoeal diseases. As a consequence, about 6,000 children die each day of dehydration due to diarrhoea. Adequate water treatment methods and safe storage of drinking water, combined with hygiene promotion, are required to prevent the population without access to safe drinking water from illness and death. Solar water disinfection (SODIS is a new water treatment to be applied at household level with a great potential to reduce diarrhoea incidence of users. The method is very simple and the only resources required for its application are transparent PET plastic bottles (or glass bottles and sufficient sunlight: microbiologically contaminated water is filled into the bottles and exposed to the full sunlight for 6 hours. During solar exposure, the diarrhoea causing pathogens are killed by the UV-A radiation of the sunlight. At present, SODIS is used by about 2 Million users in more than 20 countries of the South. Diarrhoea incidence of users significantly has been reduced by 30 to 70 %. A careful and long-term community education process that involves creating awareness on the importance of treating drinking water and initiates behaviour change is required to establish the sustainable practice of SODIS at community level. In Madagascar, more than 160 children younger than 5 years die each day from malaria, diarrhoea and acute respiratory illnesses. The application of household water treatment methods such as SODIS significantly could contribute to improve their health.

  18. Level of Water Awareness at Some Jordanian Universities Studentâ??s

    OpenAIRE

    Mohamad Said Damanhouri; Bashar Abdallah Al-Saleem; Yousra Yousef AL-Ali

    2012-01-01

    Problem statement: Jordan has been facing shortage in water sector during the last three decades due to natural and society factors, weakness of water awareness is one of these Society factors, so this study focused on the level of water awareness in fields of; water significant in life, water problem in Jordan, water conservation at part of Jordanian society. Approach: The study aimed to Investigate how some Jordanian Universities students behave to identify the level of water awareness in s...

  19. Fractal water quality fluctuations spanning the periodic table in an intensively farmed watershed.

    Science.gov (United States)

    Aubert, Alice H; Kirchner, James W; Gascuel-Odoux, Chantal; Faucheux, Mikael; Gruau, Gérard; Mérot, Philippe

    2014-01-21

    Recently developed measurement technologies can monitor surface water quality almost continuously, creating high-frequency multiparameter time series and raising the question of how best to extract insights from such rich data sets. Here we use spectral analysis to characterize the variability of water quality at the AgrHys observatory (Western France) over time scales ranging from 20 min to 12 years. Three years of daily sampling at the intensively farmed Kervidy-Naizin watershed reveal universal 1/f scaling for all 36 solutes, yielding spectral slopes of 1.05 ± 0.11 (mean ± standard deviation). These 36 solute concentrations show varying degrees of annual cycling, suggesting different controls on watershed export processes. Twelve years of daily samples of SO4, NO3, and dissolved organic carbon (DOC) show that 1/f scaling does not continue at frequencies below 1/year in those constituents, whereas a 12-year daily record of Cl shows a general 1/f trend down to the lowest measurable frequencies. Conversely, approximately 12 months of 20 min NO3 and DOC measurements show that at frequencies higher than 1/day, the spectra of these solutes steepen to slopes of roughly 3, and at time scales shorter than 2-3 h, the spectra flatten to slopes near zero, reflecting analytical noise. These results confirm and extend the recent discovery of universal fractal 1/f scaling in water quality at the relatively pristine Plynlimon watershed in Wales, further demonstrating the importance of advective-dispersive transport mixing in catchments. However, the steeper scaling at subdaily time scales suggests additional short-term damping of solute concentrations, potentially due to in-stream or riparian processes. PMID:24328425

  20. CFNN based water level control for nuclear steam generator

    International Nuclear Information System (INIS)

    Because normal PID controller can't change its parameters according to the change of control object parameters. In this paper, the compensatory fuzzy neural network (CFNN) was used with a simplified model of nuclear steam generator (NSG) to design a NSG water level controller. Compensatory neurons which were introduced in the CFNN will make the control system improve the quality of fault tolerant and more stable. Meanwhile compensative fuzzy computation is optimized dynamically in the study algorithm of neural network, therefore the network is much more adaptive and the training speed is much faster. The results of simulation show that under this control method the system has smaller maximum overshoot and faster convergence speed than that of under normal PID control method. The CFNN can not only adjust parameters properly on line, but also can optimized relevant fuzzy reasoning in dynamic way, so it suit to be used on ling learning and control. The control method used in this paper is meaningful to the research of NSG water level intelligent control. (authors)

  1. Fluctuations in the meiofauna of the Aufwuchs community in a brackish-water lagoon

    Science.gov (United States)

    Little, Colin

    1986-08-01

    The organization of the Aufwuchs community in a brackish-water lagoon (Swanpool, Falmouth, U.K.) is described. Changes in the population densities of encrusting bryozoans and mobile meiofauna are described for a period of 3 years. Most meiofaunal species reached peak densities in the spring (January-March). These included tardigrades ( Macrobiotus sp.), oligochaetes ( Nais elinguis, Chaetogaster diaphanus), the harpacticoid copepod Schizopera clandestina, ostracods, the nematodes Dichromadora geophila and Theristus spp., and possibly the nematodes Chromadorina germanica and Atrochromadora microlaima. Other meiofaunal populations peaked in summer (July-September), and these included the chironomid Chironomus salinarius, the harpacticoid copepod Nitocra spinipes and the nematode Adoncholaimus thalassophygas. Two further species, the mite Halacarus balticus and the nematode Aphelencoides sp., showed irregular bursts in numbers. It is concluded that the spring-peaking species increased in numbers dependent upon the growth of the Aufwuchs, and particularly of the surface film of diatoms, while the summer-peaking species may have been controlled more by limiting values of salinity and temperature. These conclusions are contrasted with the general view of salinity as the over-riding factor in brackish-water ecosystems.

  2. Differential equations governing slip-induced pore-pressure fluctuations in a water-saturated granular medium

    Science.gov (United States)

    Iverson, R.M.

    1993-01-01

    Macroscopic frictional slip in water-saturated granular media occurs commonly during landsliding, surface faulting, and intense bedload transport. A mathematical model of dynamic pore-pressure fluctuations that accompany and influence such sliding is derived here by both inductive and deductive methods. The inductive derivation shows how the governing differential equations represent the physics of the steadily sliding array of cylindrical fiberglass rods investigated experimentally by Iverson and LaHusen (1989). The deductive derivation shows how the same equations result from a novel application of Biot's (1956) dynamic mixture theory to macroscopic deformation. The model consists of two linear differential equations and five initial and boundary conditions that govern solid displacements and pore-water pressures. Solid displacements and water pressures are strongly coupled, in part through a boundary condition that ensures mass conservation during irreversible pore deformation that occurs along the bumpy slip surface. Feedback between this deformation and the pore-pressure field may yield complex system responses. The dual derivations of the model help explicate key assumptions. For example, the model requires that the dimensionless parameter B, defined here through normalization of Biot's equations, is much larger than one. This indicates that solid-fluid coupling forces are dominated by viscous rather than inertial effects. A tabulation of physical and kinematic variables for the rod-array experiments of Iverson and LaHusen and for various geologic phenomena shows that the model assumptions commonly are satisfied. A subsequent paper will describe model tests against experimental data. ?? 1993 International Association for Mathematical Geology.

  3. Ground-water levels near the top of the water-table mound, western Cape Cod, Massachusetts, 2002-04

    Science.gov (United States)

    Massey, Andrew J.; Carlson, Carl S.; LeBlanc, Denis R.

    2006-01-01

    In January 2002 the U.S. Geological Survey began continuous water-level monitoring in three wells in the vicinity of the Southeast Ranges of Camp Edwards, near the Impact Area of the Massachusetts Military Reservation on Cape Cod. The purpose of this effort was to examine how water levels at sites with different unsaturated-zone thicknesses near the top of the water-table mound beneath western Cape Cod are affected by temporally variable recharge from precipitation, which is the sole source of water to the sand and gravel aquifer. The depths to water at the well sites are about 18, 30, and 101 feet below land surface. This report presents the first 3 years of water-level records and an estimate of aquifer recharge calculated from climatological measurements by the Jensen and Haise method and the Thornthwaite method. The water levels in the three wells varied temporally by about 4.5 feet during the study period. A comparison of the water levels with those measured in a nearby monitoring well with about 42 years of monthly measurements indicates that the 3-year monitoring period included the lowest water levels on western Cape Cod since the drought of the 1960's. The response of water levels to recharge was related to the depth to water. Water levels in the two wells with shallow depths to water responded quickly (within hours or days) to recharge, whereas the water-level response in the well with the greatest depth to water often lagged the recharge event by a month or more. The variations in the water levels among the wells changed as the location of the top of the water-table mound moved with the changing water-table altitude.

  4. Response of the Apodi-Mossoró estuary-incised valley system (NE Brazil) to sea-level fluctuations

    Scientific Electronic Library Online (English)

    Helenice, Vital; Samia F.Lima, Furtado; Moab Praxedes, Gomes.

    Full Text Available Este estudo utiliza a integração de dados sísmicos de alta resolução, batimétricos, SRTM e imagens de satélite para desenvolvimento da estratigrafia relativa visando entender as variações do nível do mar durante o Quaternário no estuário do rio Apodi-Mossoró e plataforma adjacente, nordeste do Brasi [...] l. A principal feição identificada foi um canal submerso, na plataforma interna, parcialmente preenchido, provavelmente relacionado com o sistema de vales incisos formado durante o rebaixamento do nível do mar no Pleistoceno. O canal apresenta duas direções principais (NW-SE e NE-SW), em forma da letra J, aparentemente controladas pelas estruturas tectônicas da Bacia Potiguar. A margem oeste do canal é relativamente soerguida em relação à margem leste. Com base nos dados sísmicos foi possível identificar uma descontinuidade presente em toda a área, interpretada como o limite Pleistoceno/Holoceno, bem como sismofácies referentes a padrões de preenchimento e sedimentação do canal submerso e da plataforma durante a subida do nível do mar no Holoceno. Abstract in english This study focuses on the Quaternary sea level changes in the Apodi-Mossoró Estuary and adjacent shelf, Northeastern Brazil, based on the analysis of high-resolution seismic profiles, integrated with echosounder, SRTM and satellite image data. We use these data to develop a relative stratigraphy. An [...] incised-valley extending from the Apodi-Mossoró Estuary onto the shelf dominates the investigated area. In very shallow waters (down to 10 m depth) the channel lies mainly in a NW-SE direction, changing to NE-SW in waters below10 m, in the form of a J-shaped valley. The southern flank of the shallow channel presents an abrupt morphology, probably determined by a residual scarp due to neotectonic reactivation of a pre-existing fault. This incised-valley can be correlated with a former river valley formed during the late Pleistocene fall in sea-level. The base-level change related to this drop in sea level can be regionally expressed on seismic lines as a laterally-continuous stratigraphic surface named Horizon I, interpreted as representing the sub-aerial exposure of the continental shelf. Many incised valleys were excavated on this exposed shelf, including that of the Apodi-Mossoró Estuary and its incised valley system. This incised valley has lain buried since the Holocene transgression. The Holocene sediments present sub-horizontal layers, or they have filled the incised valley with oblique features.

  5. Response of the Apodi-Mossoró estuary-incised valley system (NE Brazil to sea-level fluctuations

    Directory of Open Access Journals (Sweden)

    Helenice Vital

    2010-01-01

    Full Text Available This study focuses on the Quaternary sea level changes in the Apodi-Mossoró Estuary and adjacent shelf, Northeastern Brazil, based on the analysis of high-resolution seismic profiles, integrated with echosounder, SRTM and satellite image data. We use these data to develop a relative stratigraphy. An incised-valley extending from the Apodi-Mossoró Estuary onto the shelf dominates the investigated area. In very shallow waters (down to 10 m depth the channel lies mainly in a NW-SE direction, changing to NE-SW in waters below10 m, in the form of a J-shaped valley. The southern flank of the shallow channel presents an abrupt morphology, probably determined by a residual scarp due to neotectonic reactivation of a pre-existing fault. This incised-valley can be correlated with a former river valley formed during the late Pleistocene fall in sea-level. The base-level change related to this drop in sea level can be regionally expressed on seismic lines as a laterally-continuous stratigraphic surface named Horizon I, interpreted as representing the sub-aerial exposure of the continental shelf. Many incised valleys were excavated on this exposed shelf, including that of the Apodi-Mossoró Estuary and its incised valley system. This incised valley has lain buried since the Holocene transgression. The Holocene sediments present sub-horizontal layers, or they have filled the incised valley with oblique features.Este estudo utiliza a integração de dados sísmicos de alta resolução, batimétricos, SRTM e imagens de satélite para desenvolvimento da estratigrafia relativa visando entender as variações do nível do mar durante o Quaternário no estuário do rio Apodi-Mossoró e plataforma adjacente, nordeste do Brasil. A principal feição identificada foi um canal submerso, na plataforma interna, parcialmente preenchido, provavelmente relacionado com o sistema de vales incisos formado durante o rebaixamento do nível do mar no Pleistoceno. O canal apresenta duas direções principais (NW-SE e NE-SW, em forma da letra J, aparentemente controladas pelas estruturas tectônicas da Bacia Potiguar. A margem oeste do canal é relativamente soerguida em relação à margem leste. Com base nos dados sísmicos foi possível identificar uma descontinuidade presente em toda a área, interpretada como o limite Pleistoceno/Holoceno, bem como sismofácies referentes a padrões de preenchimento e sedimentação do canal submerso e da plataforma durante a subida do nível do mar no Holoceno.

  6. Impact assessment of climate change and human activities on annual highest water level of Taihu Lake

    Directory of Open Access Journals (Sweden)

    Qing-fang HU

    2009-03-01

    Full Text Available The annual highest water level of Taihu Lake (Zm is very significant for flood management in the Taihu Basin. This paper first describes the inter-annual and intra-annual traits of Zm from 1956 to 2000. Then, using the Mann-Kenall (MK and Spearman (SP nonparametric tests, the long-term change trends of area precipitation and pan evaporation in the Taihu Basin are determined. Meanwhile, using the Morlet wavelet transformation, the fluctuation patterns and change points of precipitation and pan evaporation are analyzed. Also, human activities in the Taihu Basin are described, including land use change and hydraulic project construction. Finally, the relationship between Zm, the water level of Taihu Lake 30 days prior to the day of Zm (Z0, and the 30-day total precipitation and pan evaporation prior to the day of Zm (P and E0, respectively is described based on multi-linear regression equations. The relative influence of climate change and human activities on the change of Zm is quantitatively ascertained. The results demonstrate that: (1 Zm was distinctly higher during the 1980-2000 period than during the 1956-1979 period, and the 30 days prior to the day of Zm are the key phase influencing Zm every year; (2 P increased significantly at a confidence level of 95% during the 1956-2000 period, while the reverse was true for E0; (3 The relationship between Zm, P and E0 distinctly changed after 1980; (4 Climate change and human activities together caused frequent occurrences of high Zm after 1980; (5 Climate change caused a substantially greater Zm difference between the 1956-1979 and 1980-2000 periods than human activities. Climate change, as represented by P and E0, was the dominant factor raising Zm, with a relative influence ratio of 83.6%, while human activities had a smaller influence ratio of 16.4%.

  7. Characterisation of Culex quinquefasciatus (Diptera: Culicidae) larval habitats at ground level and temporal fluctuations of larval abundance in Córdoba, Argentina

    Scientific Electronic Library Online (English)

    Marta, Grech; Paolo, Sartor; Elizabet, Estallo; Francisco, Luduena-Almeida; Walter, Almiron.

    2013-09-01

    Full Text Available The aims of this study were to characterise the ground-level larval habitats of the mosquito Culex quinquefasciatus, to determine the relationships between habitat characteristics and larval abundance and to examine seasonal larval-stage variations in Córdoba city. Every two weeks for two years, 15 [...] larval habitats (natural and artificial water bodies, including shallow wells, drains, retention ponds, canals and ditches) were visited and sampled for larval mosquitoes. Data regarding the water depth, temperature and pH, permanence, the presence of aquatic vegetation and the density of collected mosquito larvae were recorded. Data on the average air temperatures and accumulated precipitation during the 15 days prior to each sampling date were also obtained. Cx. quinquefasciatus larvae were collected throughout the study period and were generally most abundant in the summer season. Generalised linear mixed models indicated the average air temperature and presence of dicotyledonous aquatic vegetation as variables that served as important predictors of larval densities. Additionally, permanent breeding sites supported high larval densities. In Córdoba city and possibly in other highly populated cities at the same latitude with the same environmental conditions, control programs should focus on permanent larval habitats with aquatic vegetation during the early spring, when the Cx. quinquefasciatus population begins to increase.

  8. On the evaluation of environmental condition by the level of fluctuating asymmetry in anuran amphibian of lake frog (Rana ridibunda as an example ?? ?????? ????????? ?????????? ????? ?? ?????? ????????????? ?????????? ? ?????????? ??????? ?? ??????? ??????? ??????? (Rana ridibunda

    Directory of Open Access Journals (Sweden)

    Lada Georgiy Arcadyevich

    2012-11-01

    Full Text Available The possibility of the usage of environmental condition evaluation by the level of fluctuating asymmetry in anuram amphibians is discussed. On the basis of original results and literature cited the conclusion is made that similar studies must be provided with the thought-over choice of studied objects and used characteristics as well as by the objective search of the causes with the account of all the assemblage of ecological factors acting on the development of an organism.??????????? ??????????? ????????????? ?????? ????????? ?????????? ????? ?? ?????? ????????????? ?????????? ? ?????????? ???????????. ?? ????????? ??????????? ??????????? ? ?????????? ???????????? ?????????? ???????? ?????, ??? ???????? ?????? ?????? ?????????????? ??????????? ??????? ???????? ???????????? ? ???????????? ?????????, ? ????? ??????????? ??????? ?????? ? ?????? ???? ???????????? ????????????? ????????, ??????????? ?? ???????? ??????????.

  9. Estimation of the influence of level fluctuations of the Caspian Sea on navigation and development of activities on the improvement of the condition of the infrastructure of waterways in the delta of the Astrakhan region

    Directory of Open Access Journals (Sweden)

    Karasaeva Al’finur Ravil’evna

    2010-10-01

    Full Text Available According experts’ forecasts, the fall of the level of the Caspian Sea, which has been recently stabilized on the mark – minus 26.5 m. on the coast of the Russian Federation, is expected. The modern condition of waterways of the Astrakhan region is considered due to the fact that navigation belongs to basic branches of the national economy, depending on fluctuations of the sea level. It is noticed that many objects of the infrastructure of the Astrakhan region, such as industrial enterprises, agricultural and fishing organizations, and ports, including the port Olya, are situated in so-called "coastal zone of risk". It is offered to apply bank protection of half-slope type as means to protect the given territo-ries from the influence of waters of the Caspian Sea. It is a levee, which frontal slope is strengthened by precast concrete slabs.

  10. Non Invasive Water Level Monitoring on Boiling Water Reactors Using Internal Gamma Radiation: Application of Soft Computing Methods

    International Nuclear Information System (INIS)

    To provide best knowledge about safety-related water level values in boiling water reactors (BWR) is essentially for operational regime. For the water level determination hydrostatic level measurement systems are almost exclusively applied, because they stand the test over many decades in conventional and nuclear power plants (NPP). Due to the steam generation especially in BWR a specific phenomenon occurs which leads to a water-steam mixture level in the reactor annular space and reactor plenum. The mixture level is a high transient non-measurable value concerning the hydrostatic water level measuring system and it significantly differs from the measured collapsed water level. In particular, during operational and accidental transient processes like fast negative pressure transients, the monitoring of these water levels is very important. In addition to the hydrostatic water level measurement system a diverse water level measurement system for BWR should be used. A real physical diversity is given by gamma radiation distribution inside and outside the reactor pressure vessel correlating with the water level. The vertical gamma radiation distribution depends on the water level, but it is also a function of the neutron flux and the coolant recirculation pump speed. For the water level monitoring, special algorithms are required. An analytical determination of the gamma radiation distribution outside the reactor pressure vessel is impossible due to the multitude of radiis impossible due to the multitude of radiation of physical processes, complicated non-stationary radiation source distribution and complex geometry of fixtures. For creating suited algorithms Soft Computing methods (Fuzzy Sets Theory, Artificial Neural Networks, etc.) will be used. Therefore, a database containing input values (gamma radiation distribution) and output values (water levels) had to be built. Here, the database was established by experiments (data from BWR and from a test setup) and simulation with the authorised thermo-fluid code ATHLET. (authors)

  11. Water levels in periodically measured wells in the Yucca Mountain Area, Nevada, 1988

    International Nuclear Information System (INIS)

    This report presents water-level data for 10 wells that were periodically measured in 1988 in the Yucca Mountain Area, Nevada. Water levels measured during 1987 are included in the report for reference. The report includes discussions of the methods used and corrections applied to obtain water-level depths and altitudes from onsite measurements. Water levels for each well are presented in tabular and graphical (hydrograph) form. The altitude of the water level in the upper part of the saturated zone is about 775 meters above sea level to the west of and along part of the crest of Yucca Mountain; along the eastern edge and southern end of Yucca Mountain, the water level is 728 to 730 meters above sea level. The water-level data were obtained to help evaluate the suitability of the area for storing high-level nuclear waste. 14 refs., 2 figs., 2 tabs

  12. Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin, With Special Emphasis on Responses of an Oligotrophic Seepage Lake to Changes in Phosphorus Loading and Water Level

    Science.gov (United States)

    Robertson, Dale M.; Rose, William J.; Juckem, Paul F.

    2009-01-01

    Whitefish Lake, which is officially named Bardon Lake, is an oligotrophic, soft-water seepage lake in northwestern Wisconsin, and classified by the Wisconsin Department of Natural Resources as an Outstanding Resource Water. Ongoing monitoring of the lake demonstrated that its water quality began to degrade (increased phosphorus and chlorophyll a concentrations) around 2002 following a period of high water level. To provide a better understanding of what caused the degradation in water quality, and provide information to better understand the lake and protect it from future degradation, the U.S. Geological Survey did a detailed study from 2004 to 2008. The goals of the study were to describe the past and present water quality of the lake, quantify water and phosphorus budgets for the lake, simulate the potential effects of changes in phosphorus inputs on the lake's water quality, analyze changes in the water level in the lake since 1900, and relate the importance of changes in climate and changes in anthropogenic (human-induced) factors in the watershed to the water quality of the lake. Since 1998, total phosphorus concentrations increased from near the 0.005-milligrams per liter (mg/L) detection limit to about 0.010 mg/L in 2006, and then decreased slightly in 2007-08. During this time, chlorophyll a concentrations and Secchi depths remained relatively stable at about 1.5 micrograms per liter (ug/L) and 26 feet, respectively. Whitefish Lake is typically classified as oligotrophic. Because the productivity in Whitefish Lake is limited by phosphorus, phosphorus budgets were constructed for the lake. Because it was believed that much of its phosphorus comes from the atmosphere, phosphorus deposition was measured in this study. Phosphorus input from the atmosphere was greater than computed based on previously reported wetfall phosphorus concentrations. The concentrations and deposition rates can be used to estimate atmospheric loading in future lake studies. The average annual load of phosphorus to the lake was 232 pounds: 56 percent from precipitation, 27 percent from groundwater, and 16 percent from septic systems. During a series of dry years (low water levels) and wet years (high water levels), the inputs of water and phosphorus ranged by only 10-13 percent. Results from the Canfield and Bachmann eutrophication model and Carlson trophic-state-index equations demonstrated that the lake directly responds to changes in external phosphorus loading, with percent change in chlorophyll a being similar to the percent change in loading and the change in total phosphorus and Secchi depth being slightly smaller. Therefore, changes in phosphorus loading should affect the water quality of the lake. Specific scenarios that simulated the effects of anthropogenic (human-induced) and climatic (water level) changes demonstrated that: surface-water inflow (runoff) based on current development has little effect on pelagic water quality, changes in the inputs from septic systems and development in the watershed could have a large effect on water quality, and decreases in water and phosphorus loading during periods of low water level had little effect on water quality. Sustained high water levels, resulting from several wet years with relatively high water and phosphorus input, however, could cause a small degradation in water quality. Although high water levels may be associated with a degradation in water quality, it appears that anthropogenic changes in the watershed may be more important in affecting the future water quality of the lake. Fluctuations in water levels since 1998 are representative of what has occurred since 1900, with fluctuations of about 3 feet occurring about every 15 years. Based on total phosphorus concentrations inferred from sediment core analysis, there has been little long-term change in water quality and there has been a slight deterioration in water quality following most periods of high water levels. There

  13. Natural radioactivity levels in different mineral waters from Bulgaria

    International Nuclear Information System (INIS)

    The total radioactivity content of 76 mineral waters from different districts in Bulgaria was determined. Natural radioactivity levels resulting from uranium, radium-226, gross alpha and gross beta activity were measured. The results show that the specific activity range from < 0.02 Bq/l to 1.34 (12) Bq/l and from 0.068 (23) Bq/l to 2.60 (50) Bq/l for gross alpha and gross beta activity respectively. For natural Uranium the results vary between 0.020 (5) ?g/l and 180(50) ?g/l. Radium-226 content is between < 0.03 Bq/l to 0.296 (75) Bq/l. Due to differences in the geological structure of the aquifer, a large difference in values of the radioactive content was mSv/year. Excluding one value, TID do not exceed the permissible limit of 0.10 mSv/year. The correlations between investigated isotopes and Total Dissolved observed. The estimated Total Indicative Dose (TID) ranged from 0.0113 (57) mSv/year to 0.1713 (481) Solvents (TDS) in water were carried out. The results do not show a strong correlation between TDS values and dissolved radionuclides. (author)

  14. Emergency action levels for light water reactors. Draft report

    International Nuclear Information System (INIS)

    United States nuclear power plants are currently preparing revised radiological emergency response plans. As part of these plans, each licensee is establishing plant-specific instrumentation readings, called emergency action levels (EALs), that indicate the presence of a problem and the need to declare one of four classes of emergency as designated by the U.S. Nuclear Regulatory Commission. In this report, the EALs prepared for a pressurized water reactor and a boiling water reactor are assessed to determine whether they meet the requirements of NUREG-0654, Rev. 1 Appendix 1. In addition, five recent nuclear incidents are studied to determine how their outcomes might have been affected by the new emergency response plans. Most of the EALs reviewed were judged adequate. In some cases, alternate EALs or sets of generic EALs are proposed to meet the intent of NUREG-0654 Rev 1 Appendix 1, and the wording of some of the initiating conditions for the four emergency classes is clarified. For three of the five incidents reviewed, the new emergency response plans probably would not have affected the outcome; in one case, the plans would probably have prevented core damage; and any effect on the outcome of the last incident is uncertain

  15. Investigation of pond water levels during the 1972 waterfowl brooding season

    US Fish and Wildlife Service, Department of the Interior — A report on water levels in Malheur ponds in 1972 Water level management in the ponds of Malheur National Wildlife Refuge is important in providing food and habitat...

  16. Trend Analysis of Ground-Water Levels and Spring Discharge in the Yucca Mountain Region, Nevada and California, 1960-2000

    International Nuclear Information System (INIS)

    Ground-water level and discharge data from 1960 to 2000 were analyzed for the Yucca Mountain region of southern Nevada and eastern California. Included were water-level data from 37 wells and a fissure (Devils Hole) and discharge data from five springs and from a flowing well. Data were evaluated for variability and for upward, downward, or cyclic trends with an emphasis on the period 1992-2000. Potential factors causing trends in water levels and discharge include ground-water withdrawal, infiltration of precipitation, earthquakes, evapotranspiration, barometric pressure, and earth tides. Statistically significant trends in ground water levels or spring discharge from 1992 to 2000 were upward at 12 water-level sites and downward at 14 water-level sites and 1 spring-discharge site. In general, the magnitude of the change in water level from 1992 to 2000 was small (less than 2 feet), except where influenced by pumping or local effects such as possible equilibration from well construction or diversion of nearby surface water. Seasonal trends are superimposed on some of the long-term (1992-2000) trends in water levels and discharge. Factors causing seasonal trends include barometric pressure, evapotranspiration, and pumping. The magnitude of seasonal change in water level can vary from as little as 0.05 foot in regional aquifers to greater than 5 feet in monitoring wells near large supply wells in the Amargosa Farms area. Three major episodes of earthquake activity affecajor episodes of earthquake activity affected water levels in wells in the Yucca Mountain region between 1992 and 2000: the Landers/Little Skull Mountain, Northridge, and Hector Mine earthquakes. The Landers/Little Skull Mountain earthquakes, in June 1992, had the largest observed effect on water levels and on discharge during the study period. Monthly measurements of wells in the study network show that earthquakes affected water levels from a few tenths of a foot to 3.5 feet. In the Ash Meadows area, water levels remained relatively stable from 1992 to 2000, with some water levels showing small rising trends and some declining slightly. Possible reasons for water-level fluctuations at sites AD-6 (Tracer Well 3), AM-5 (Devils Hole Well), and AM-4 (Devils Hole) from 1960 to 2000 include climate change, local and regional ground-water withdrawals, and tectonic activity. In Jackass Flats, water levels from 1992 to 2000 in six wells adjacent to Fortymile Wash displayed either small upward trends or no upward or downward trend. Comparison of trends in water levels from 1983 to 2000 for these six wells shows good correlations between all wells and suggests a common mechanism controlling water levels in the area. Of the likely controls on the system-precipitation or pumping in Jackass Flats-precipitation appears to be the predominant factor controlling water levels near Fortymile Wash. Water levels in the heavily pumped Amargosa Farms area declined from about 10 to 30 feet from 1964 to 2000. Water-level declines accelerated beginning in the early 1990's as pumping rates increased substantially. Pumping in the Amargosa Farms area may affect water levels in some wells as far away as 5-14 miles. The water level at site DV-3 (Travertine Point 1 Well) and discharge at site DV-2 (Navel Spring), both in the Death Valley hydrographic area, had downward trends from 1992 to 2000. The cause of these downward trends may be linked to earthquakes, pumping in the Amargosa Farms area, or both

  17. Trend analysis of ground-water levels and spring discharge in the Yucca Mountain Region, Nevada and California, 1960-2000

    Science.gov (United States)

    Fenelon, Joseph M.; Moreo, Michael T.

    2002-01-01

    Ground-water level and discharge data from 1960 to 2000 were analyzed for the Yucca Mountain region of southern Nevada and eastern California. Included were water-level data from 37 wells and a fissure (Devils Hole) and discharge data from five springs and from a flowing well. Data were evaluated for variability and for upward, downward, or cyclic trends with an emphasis on the period 1992-2000. Potential factors causing trends in water levels and discharge include ground-water withdrawal, infiltration of precipitation, earthquakes, evapotranspiration, barometric pressure, and earth tides. Statistically significant trends in ground-water levels or spring discharge from 1992 to 2000 were upward at 12 water-level sites and downward at 14 water-level sites and 1 spring-discharge site. In general, the magnitude of the change in water level from 1992 to 2000 was small (less than 2 feet), except where influenced by pumping or local effects such as possible equilibration from well construction or diversion of nearby surface water. Seasonal trends are superimposed on some of the long-term (1992-2000) trends in water levels and discharge. Factors causing seasonal trends include barometric pressure, evapotranspiration, and pumping. The magnitude of seasonal change in water level can vary from as little as 0.05 foot in regional aquifers to greater than 5 feet in monitoring wells near large supply wells in the Amargosa Farms area. Three major episodes of earthquake activity affected water levels in wells in the Yucca Mountain region between 1992 and 2000: the Landers/Little Skull Mountain, Northridge, and Hector Mine earthquakes. The Landers/Little Skull Mountain earthquakes, in June 1992, had the largest observed effect on water levels and on discharge during the study period. Monthly measurements of wells in the study network show that earthquakes affected water levels from a few tenths of a foot to 3.5 feet. In the Ash Meadows area, water levels remained relatively stable from 1992 to 2000, with some water levels showing small rising trends and some declining slightly. Possible reasons for water-level fluctuations at sites AD-6 (Tracer Well 3), AM-5 (Devils Hole Well), and AM-4 (Devils Hole) from 1960 to 2000 include climate change, local and regional ground-water withdrawals, and tectonic activity. In Jackass Flats, water levels from 1992 to 2000 in six wells adjacent to Fortymile Wash displayed either small upward trends or no upward or downward trend. Comparison of trends in water levels from 1983 to 2000 for these six wells shows good correlations between all wells and suggests a common mechanism controlling water levels in the area. Of the likely controls on the system--precipitation or pumping in Jackass Flats--precipitation appears to be the predominant factor controlling water levels near Fortymile Wash. Water levels in the heavily pumped Amargosa Farms area declined from about 10 to 30 feet from 1964 to 2000. Water-level declines accelerated beginning in the early 1990's as pumping rates increased substantially. Pumping in the Amargosa Farms area may affect water levels in some wells as far away as 5-14 miles. The water level at site DV-3 (Travertine Point 1 Well) and discharge at site DV-2 (Navel Spring), both in the Death Valley hydrographic area, had downward trends from 1992 to 2000. The cause of these downward trends may be linked to earthquakes, pumping in the Amargosa Farms area, or both.

  18. Behaviors of extreme water level in the Pearl River Delta and possible impacts from human activities

    OpenAIRE

    Chen, Y. D.; Zhang, Q.; Yang, T.; Xu, C.; Chen, X.; Jiang, T.

    2007-01-01

    Trends and variations of the extreme water levels defined as exceeding/falling below certain thresholds (mean ± std) across the Pearl River Delta (PRD) are systematically explored using the linear regression method. Research results indicate that: 1) The upper PRD is dominated by the significant decreasing low water level, and significant increasing low water level can be identified in the lower PRD. The variations of the relative frequency of the high water level are characterized...

  19. GPS water level measurements for Indonesia's Tsunami Early Warning System

    Directory of Open Access Journals (Sweden)

    T. Schöne

    2011-03-01

    Full Text Available On Boxing Day 2004, a severe tsunami was generated by a strong earthquake in Northern Sumatra causing a large number of casualties. At this time, neither an offshore buoy network was in place to measure tsunami waves, nor a system to disseminate tsunami warnings to local governmental entities. Since then, buoys have been developed by Indonesia and Germany, complemented by NOAA's Deep-ocean Assessment and Reporting of Tsunamis (DART buoys, and have been moored offshore Sumatra and Java. The suite of sensors for offshore tsunami detection in Indonesia has been advanced by adding GPS technology for water level measurements.

    The usage of GPS buoys in tsunami warning systems is a relatively new approach. The concept of the German Indonesian Tsunami Early Warning System (GITEWS (Rudloff et al., 2009 combines GPS technology and ocean bottom pressure (OBP measurements. Especially for near-field installations where the seismic noise may deteriorate the OBP data, GPS-derived sea level heights provide additional information.

    The GPS buoy technology is precise enough to detect medium to large tsunamis of amplitudes larger than 10 cm. The analysis presented here suggests that for about 68% of the time, tsunamis larger than 5 cm may be detectable.

  20. Fluctuating water table affects gross ecosystem production and gross radiation use efficiency in a sedge-grass marsh.

    Czech Academy of Sciences Publication Activity Database

    Dušek, Ji?í; ?ížková, Hana; Stellner, Stanislav; Czerný, Radek; Kv?t, Jan

    2012-01-01

    Ro?. 692, ?. 1 (2012), s. 57-66. ISSN 0018-8158 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA MŽP(CZ) SP/2D1/93/07; GA MŠk OC08021 Institutional research plan: CEZ:AV0Z60870520 Keywords : Wetland * fen * carbon * water level * Carex acuta L. * Eddy covariance Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.985, year: 2012

  1. Effects of alternative Missouri River management plans on ground-water levels in the lower Missouri River flood plain

    Science.gov (United States)

    Kelly, Brian P.

    2000-01-01

    In 1998, the U.S. Army Corps of Engineers (USACE) proposed eight Alternative River Management Plans (ARMPs) for managing reservoir levels and water-release rates for the Missouri River. The plans include the Current Water Control Plan (CWCP), Conservation 18, 31, and 44 (C18, C31, and C44) that provide different levels of water conservation in the reservoirs during droughts, Fish and Wildlife 10, 15, and 20 (FW10, FW15, and FW20) that vary water-release rates to provide additional fish and wildlife benefits, and Mississippi River 66 (M66) that maintains a 66,000 cubic feet per second discharge at St. Louis to provide navigation support for the Mississippi River. Releases from Gavin?s Point Dam affect both the lower 1,305 kilometers of the Missouri River and ground-water levels in the lower Missouri River flood plain. Changes in the magnitude and timing of ground-water-level fluctuations in response to changes in river management could impact agriculture, urban development, and wetland hydrology along the lower Missouri River flood plain. This study compared simulated ground-water altitude and depth to ground water for the CWCP in the Missouri River alluvial aquifer near the Kansas City area between 1970 and 1980 with each ARMP, determined the average change in simulated ground-water level for selected river-stage flood pulses at selected distances from the river, and compared simulated flood pulse, ground-water responses with actual flood pulse, and ground-water responses measured in wells located at three sites along the lower Missouri River flood plain.For the model area, the percent total shallow ground-water area (depth to ground water less than 0.3048 meter) is similar for each ARMP because of overall similarities in river flow between ARMPs. The percent total shallow ground-water area for C18 is the most similar to CWCP followed by C31, M66, C44, FW10, FW15, and FW20. ARMPs C18, C31, C44, and M66 do not cause large changes in the percent shallow ground-water area when compared to CWCP. FW10 and FW15 each cause a spring increase and a summer decrease in the shallow ground-water area. FW20 has a larger spring increase in the shallow ground-water area, but the largest decrease is delayed into November. Analysis of daily changes between the ARMPs indicate large differences can exist in both duration and extent of shallow ground-water areas.A series of 12 flood pulses of 0.5-, 1-, and 3-meters in magnitude and 1-, 8-, 32-, and 128-days in duration were simulated using the ground-water flow model. A ground-water response factor (GWRF, defined as the change in ground-water level at a known distance from the river, at a specified time after the beginning of a flood pulse divided by the magnitude of the flood pulse) was determined daily for selected distances from the river. The GWRF multiplied by the magnitude of the flood pulse can be used to estimate the change in ground-water level at a known time after the beginning of a flood pulse for a known distance from the river. Flood-pulse simulation results indicate the relatively small impact on ground-water levels of small river-stage fluctuations of short duration as might occur daily or weekly. The larger impact on ground-water levels from larger river-stage increases of longer duration indicate the importance of river management flow releases, seasonal changes in river flow, and the effects of continuous high-river stage for long periods on ground-water levels of the lower Missouri River flood plain.A comparison of model results to well hydrographs from three areas along the lower Missouri River flood plain was used to determine how closely the simulated GWRFs matched the measured GWRFs for similar flood pulses and the transferability of GWRFs to other parts of the lower Missouri River flood plain. The comparison between the measured and simulated ground-water responses indicate that the simulated ground-water responses can provide a reasonable estimate of the ground-water resp

  2. Survey of fluoride levels in vended water stations.

    Science.gov (United States)

    Jadav, Urvi G; Archarya, Bhavini S; Velasquez, Gisela M; Vance, Bradley J; Tate, Robert H; Quock, Ryan L

    2014-01-01

    This study sought to measure the fluoride concentration of water derived from vended water stations (VWS) and to identify its clinical implications, especially with regard to caries prevention and fluorosis. VWS and corresponding tap water samples were collected from 34 unique postal zip codes; samples were analyzed in duplicate for fluoride concentration. Average fluoride concentration in VWS water was significantly lower than that of tap water (P Fluoride concentration in the VWS water ranged from fluoride supplementation may be indicated. Conversely, to minimize the risk of fluorosis in infants consuming reconstituted infant formula, water from a VWS may be used. PMID:25184716

  3. Water levels in wells J-11 and J-12, 1989-91, Yucca Mountain Area, Nevada

    International Nuclear Information System (INIS)

    Water levels have been measured in the Yucca Mountain area, Nevada, since 1981 in order to gain a better understanding of the ground-water flow system in the area. Water levels in wells J-11 and J-12 have been periodically measured using calibrated reeled steel tapes since 1989, however, calculation of water-level altitude was not possible prior to 1993 due to missing reference elevations. These elevations were determined in 1993 by the U.S. Geological Survey. During 1989-91, water-level altitudes for well J-11 ranged from 732.09 to 732.40 meters and the mean water-level altitude was 732.19 meters. During 1989-91, water-level altitudes for well J-12 ranged from 727.84 to 728.03 meters, and the mean water-level altitude was 727.95 meters

  4. Fluctuating sea levels off Bombay (India) between 14,500 and 10,000 years before present

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; Hashimi, N.H.; Menezes, E.T.; Wagh, A.B.

    1992-01-01

    A 26.5-metre-long core collected from the outer-shelf area off Bombay (India) at 75 m water depth showed ooids and shallow-water benthic foraminifera all along the core. The presence of these well-known indicators of shallow-water environment...

  5. Drinking cholera : Salinity levels and palatability of drinking water in coastal Bangladesh

    DEFF Research Database (Denmark)

    Grant, Stephen Lawrence; Tamason, Charlotte Crim

    2015-01-01

    Objectives: To measure the salinity levels of common water sources in coastal Bangladesh and explore perceptions of water palatability among the local population to investigate the plausibility of linking cholera outbreaks in Bangladesh with ingestion of saline-rich cholera-infected river water. Methods: Hundred participants took part in a taste-testing experiment of water with varying levels of salinity. Salinity measurements were taken of both drinking and non-drinking water sources. Informal group discussions were conducted to gain an in-depth understanding of water sources and water uses. Results: Salinity levels of non-drinking water sources suggest that the conditions for Vibrio cholerae survival exist 7-8 days within the local aquatic environment. However, 96% of participants in the taste-testing experiment reported that they would never drink water with salinity levels that would be conducive to V. cholerae survival. Furthermore, salinity levels of participant's drinking water sources were all well below the levels required for optimal survival of V. cholerae. Respondents explained that they preferred less salty and more aesthetically pleasing drinking water. Conclusion: Theoretically, V. cholerae can survive in the river systems in Bangladesh; however, water sources which have been contaminated with river water are avoided as potential drinking water sources. Furthermore, there are no physical connecting points between the river system and drinking water sources among the study population, indicating that the primary driver for cholera cases in Bangladesh is likely not through the contamination of saline-rich river water into drinking water sources.

  6. To save water or not? : A study of water scarcity at multiple levels, and people's attitudestowards it in Bangalore, India

    OpenAIRE

    Bognäs, Désirée

    2011-01-01

    In a situation where population growth and development is to be sustained throughnaturally limited water resources, something needs to be done to either render waterusage more effective or make more water available. This is the situation in Bangalore Urban District (BUD), an ever growing city lying far from perennial water sources. This thesis presents the water situation in BUD, and aims to analyze the current status of water resources on multiple levels in BUD. Further the aim is to look at...

  7. ERPWS: An Energy Efficient Routing Protocol for Conductive Sensor based Water Level Monitoring and Control System using Zigbee and 74HC14 Inverter

    Directory of Open Access Journals (Sweden)

    Saima Maqbool

    2013-07-01

    Full Text Available In this paper we have shown how to use conductive sensor, Zigbee and 74HC14 Inverter to monitor the water level and to control the working of pump. This project is designed to automatically fill the over head tank when it gets empty and monitor the water level in it. The motor is switched ON when the water level in the overhead tank drops below a pre fixed low level (on point and puts off the motor when water level rises up to pre fixed high level (off point.The motor is also switched off during the following conditions: when the sump water is exhausted before filling overhead tank, pump running dry, mains voltage fluctuations. We also introduce an energy efficient routing protocol for Wireless Sensor Networks (ERPWS for Conductive Sensor based Water Level Monitoring and Control System using Zigbee (XBEE 802.15.4 in terms of energy consumptions, the packet loss ratio, network lifetime and the average delivery delay. The XBEE used here is XBEE Pro Series 1(XBP24-AWI-001 and IC used is 74HC14 Hex Inverting Schmitt trigger. Simulation results have been obtained by using NS2 simulator. The evaluation results show that the energy consumption of routing using ERPWS is significantly lower than LEACH and traditional routing protocols.

  8. Analysis of the causes of price fluctuations of dairy products at individual levels of the product vertica

    OpenAIRE

    Z. Gebeltová

    2010-01-01

    The paper analyzes the reasons for the prices of milk and milk products in the Czech Republic for the period 2008 – 2009. In January 2008, the purchase price of raw milk was 10.08 CZK/l, and in the subsequent period it began to decline. At the end of 2008, the price was more than 3 crowns lower, and still the decrease continued. The research determined that the essential reason for the price fluctuations is the impact of the economic crisis. A substantial portion of the article was devoted ...

  9. Snapshots of the fluctuating hydrogen bond network in liquid water on the sub-femtosecond timescale with vibrational resonant inelastic x-ray scattering.

    Science.gov (United States)

    Pietzsch, A; Hennies, F; Miedema, P S; Kennedy, B; Schlappa, J; Schmitt, T; Strocov, V N; Föhlisch, A

    2015-02-27

    Liquid water molecules interact strongly with each other, forming a fluctuating hydrogen bond network and thereby giving rise to the anomalous phase diagram of liquid water. Consequently, symmetric and asymmetric water molecules have been found in the picosecond time average with IR and optical Raman spectroscopy. With subnatural linewidth resonant inelastic x-ray scattering (RIXS) at vibrational resolution, we take sub-femtosecond snapshots of the electronic and structural properties of water molecules in the hydrogen bond network. We derive a strong dominance of nonsymmetric molecules in liquid water in contrast to the gas phase on the sub-femtosecond timescale of RIXS and determine the fraction of highly asymmetrically distorted molecules. PMID:25768783

  10. Behaviors of extreme water level in the Pearl River Delta and possible impacts from human activities

    Directory of Open Access Journals (Sweden)

    Y. D. Chen

    2007-12-01

    Full Text Available Trends and variations of the extreme water levels defined as exceeding/falling below certain thresholds (mean ± std across the Pearl River Delta (PRD are systematically explored using the linear regression method. Research results indicate that: 1 The upper PRD is dominated by the significant decreasing low water level, and significant increasing low water level can be identified in the lower PRD. The variations of the relative frequency of the high water level are characterized by the decreasing variability in the middle PRD. However more stations show significant changes of the relative frequency of the low water level across the PRD. No confirmative changing patterns of the relative frequency of the low water level can be detected in the middle PRD; 2 When it comes to the seasonal variations of the high/low water level in JJA (high flow periods in the PRD, stations located closer to the estuary tend to exhibit increasing high/low water level. However stations located closer to the upper PRD tend to show decreasing high/low water level. Similar patterns can be identified in the high/low water level in DJF (low flow periods in the PRD; 3 The changes of the water level in the PRD are heavily affected by human interferences, e.g. in-channel dredging, sand mining and the construction of levees. The stations dominated by decreasing water level are mostly located along the river channels featured by highly-intensive dredging. The stations along the coastal regions show significant increasing extreme high/low water level. The coastal regions are not influenced by in-channel dredging, and furthermore, sediment loads from upper and middle PRD are deposited in the river mouths and which will tend to raise the water level in the estuary of the PRD. The findings of this paper may be helpful for local water resource management.

  11. Fuzzy logic control of steam generator water level in pressurized water reactors

    International Nuclear Information System (INIS)

    In this paper a fuzzy logic controller is applied to control the steam generator water level in a pressurized water reactor. The method does not require a detailed mathematical mode of the object to be controlled. The design is based on a set of linguistic rules that were adopted from the human operator's experience. After off-line fuzzy computation, the controller is a lookup table, and thus, real-time control is achieved. Shrink-and-swell phenomena are considered in the linguistic rules, and the simulation results show that their effect is dramatically reduced. The performance of the control system can also be improved by changing the input and output scaling factors, which is convenient for on-line tuning

  12. A near-uniform fluctuation of ocean bottom pressure and sea level across the deep ocean basins of the Arctic Ocean and the Nordic Seas

    Science.gov (United States)

    Fukumori, Ichiro; Wang, Ou; Llovel, William; Fenty, Ian; Forget, Gael

    2015-05-01

    Across the Arctic Ocean and the Nordic Seas, a basin-wide mode of ocean bottom pressure and sea level fluctuation is identified using satellite and in situ observations in conjunction with a global ocean circulation model and its adjoint. The variation extends across the interconnected deep ocean basins of these semi-enclosed Arctic seas, collectively called the Arctic Mediterranean, with spatially near-uniform amplitude and phase. The basin-wide fluctuation is barotropic and dominates the region's large-scale variability from sub-monthly to interannual timescales. The fluctuation results from bifurcating coastally trapped waves generated by winds along the continental slopes of the Arctic Mediterranean and its neighboring seas, including the North Atlantic Ocean. The winds drive Ekman transport across the large bathymetric gradients, forcing mass divergence between the shallow coastal area and the deep ocean basins and creating ocean bottom pressure anomalies of opposite signs in the two regions. The anomalies rapidly propagate away as barotropic coastally trapped waves with the coast and continental slope as respective boundaries. The waves subsequently bifurcate at the shallow straits connecting the Arctic Mediterranean with the rest of the globe. The straits transmit the shallow anomalies but not the deep variations, thereby inhibiting the anomalies' mutual cancelation by geographically separating the two. Anomalies that enter the deep Arctic basins equilibrate uniformly across the domain characterized by a homogeneous depth-integrated planetary potential vorticity distribution. The potential vorticity's steep gradient that borders the basins shields the region from neighboring shallow variations, giving rise to the observed spatially confined fluctuation. Compensating anomalies outside the Arctic adjust similarly across the rest of the globe but are comparatively negligible in amplitude because of the global ocean's larger area relative to that of the deep Arctic Mediterranean. The study, from a technical perspective, illustrates the utility of a model's adjoint in identifying causal mechanisms underlying a complex system.

  13. Decadal fluctuations in North Atlantic water inflow in the North Sea between 1958-2003: impacts on temperature and phytoplankton populations

    Directory of Open Access Journals (Sweden)

    Martin J. Attrill

    2008-03-01

    Full Text Available The circulation of Atlantic water along the European continental slope, in particular the inflow into the North Sea, influences North Sea water characteristics with consequent changes in the environment affecting plankton community dynamics. The long-term effect of fluctuating oceanographic conditions on the North Sea pelagic ecosystem is assessed. It is shown that (i there are similar regime shifts in the inflow through the northern North Sea and in Sea Surface Temperature, (ii long-term phytoplankton trends are influenced by the inflow only in some North Sea regions, and (iii the spatial variability in chemicophysical and biological parameters highlight the influence of smaller scale processes.

  14. Description of the US Geological Survey's water level monitoring program at the Hallam Nuclear Facility, September 1993--February 1994; Description of the collection of continuous water-level data; Description of the collection of monthly water-level data

    International Nuclear Information System (INIS)

    The US Department of Energy and the US Department of the Interior agreed to monitor water-level data in 16 observation wells located at Hallam Facility, Hallam, Nebraska. The data collection period began in September 1993 and continued through August 1994. This report contains the interim summary representing six months of data collection. Specific sections include the following: description of the US Geological Survey's monitoring program at the Hallam Nuclear Facility (Sept. 1993 to Feb. 1994); description of the collection of continuous water-level data; description of the collection of monthly water-level data; table of observation well number, latitude, longitude, and depth; table of monthly ground-water levels data; table of recorder wells, rainfall, and barometric pressure unit values; and table of recorder well, rainfall, and barometric daily values; hydrographs of selected wells

  15. Level of Water Awareness at Some Jordanian Universities Studentâ??s

    Directory of Open Access Journals (Sweden)

    Mohamad Said Damanhouri

    2012-01-01

    Full Text Available Problem statement: Jordan has been facing shortage in water sector during the last three decades due to natural and society factors, weakness of water awareness is one of these Society factors, so this study focused on the level of water awareness in fields of; water significant in life, water problem in Jordan, water conservation at part of Jordanian society. Approach: The study aimed to Investigate how some Jordanian Universities students behave to identify the level of water awareness in sectors of water, giving students positive attitudes towards water resources and conservation, uses and reduce consumption. Encourage students for voluntary collective actions as A hope to raising water awareness. The society sample study were represented by (320 Jordanian Universities students, take in consideration the following variables: Academic specialists, sex, University status and average monthly income per family. Data base for previous variables obtained by special questioner prepared for this study. Data run to statistical analysis through some simple Descriptive statistical approaches as (ANOVA. Results: The study showed that the level of water awareness towards water significant at a weak level, it reached to (57% of sample study towards water conservation. Students of scientific specializes have water awareness more than humanitarian specializes. There isnâ??t impact of University status and average monthly income on the level of water awareness. Conclusion/Recommendations: Most of study sample recognized with significant of water at life, they admit that Jordan faced water problem, but female were more than male at the level of water awarenes, also scientific specialists more than humanitarian specialties. Study recommends to enrich the curriculum of humanitarian sciences, with more topics looking for water and encourage personal activities and volunteers work to conserve water and rationalized it, also activation laws and legislation related with water.

  16. Options for future effective water management in Lombok: A multi-level nested framework

    Science.gov (United States)

    Sjah, Taslim; Baldwin, Claudia

    2014-11-01

    Previous research on water use in Lombok identified reduced water available in springs and limits on seasonal water availability. It foreshadowed increasing competition for water resources in critical areas of Lombok. This study examines preliminary information on local social-institutional arrangements for water allocation in the context of Ostrom's rules for self-governing institutions. We identify robust customary mechanisms for decision-making about water sharing and rules at a local level and suggest areas of further investigation for strengthening multi-level networked and nested frameworks, in collaboration with higher levels of government.

  17. Lake Storage Measurements For Water Resources Management: Combining Remotely Sensed Water Levels and Surface Areas

    Science.gov (United States)

    Brakenridge, G. R.; Birkett, C. M.

    2013-12-01

    Presently operating satellite-based radar altimeters have the ability to monitor variations in surface water height for large lakes and reservoirs, and future sensors will expand observational capabilities to many smaller water bodies. Such remote sensing provides objective, independent information where in situ data are lacking or access is restricted. A USDA/NASA (http://www.pecad.fas.usda.gov/cropexplorer/global_reservoir/) program is performing operational altimetric monitoring of the largest lakes and reservoirs around the world using data from the NASA/CNES, NRL, and ESA missions. Public lake-level products from the Global Reservoir and Lake Monitor (GRLM) are a combination of archived and near real time information. The USDA/FAS utilizes the products for assessing international irrigation potential and for crop production estimates; other end-users study climate trends, observe anthropogenic effects, and/or are are involved in other water resources management and regional water security issues. At the same time, the Dartmouth Flood Observatory (http://floodobservatory.colorado.edu/), its NASA GSFC partners (http://oas.gsfc.nasa.gov/floodmap/home.html), and associated MODIS data and automated processing algorithms are providing public access to a growing GIS record of the Earth's changing surface water extent, including changes related to floods and droughts. The Observatory's web site also provide both archival and near real time information, and is based mainly on the highest spatial resolution (250 m) MODIS bands. Therefore, it is now possible to provide on an international basis reservoir and lake storage change measurements entirely from remote sensing, on a frequently updating basis. The volume change values are based on standard numerical procedures used for many decades for analysis of coeval lake area and height data. We provide first results of this combination, including prototype displays for public access and data retrieval of water storage volume changes. Ground-based data can, in some cases, test the remote sensing accuracy and precision. Data accuracy requirements vary for different applications: reservoir management for flood control, agriculture, or power generation may need more accurate and timely information than (for example) regional assessments of water and food security issues. Thus, the long-term goal for the hydrological sciences community should be to efficiently mesh both types of information and with as extensive geographic coverage as possible.

  18. Stochastic modeling of Lake Van water level time series with jumps and multiple trends

    OpenAIRE

    Aksoy, H.; N. E. Unal; E. Eris; M. I. Yuce

    2013-01-01

    In 1990s, water level in the closed-basin Lake Van located in the Eastern Anatolia, Turkey has risen up about 2 m. Analysis of the hydrometeorological shows that change in the water level is related to the water budget of the lake. In this study, a stochastic model is generated using the measured monthly water level data of the lake. The model is derived after removal of trend and periodicity in the data set. Trend observed in the lake water level time series is fitted by mono- and mul...

  19. Tritium activity levels in environmental water samples from different origins

    International Nuclear Information System (INIS)

    Tritium activity was determined in environmental waters from different areas of Catalonia, using a distillation procedure before liquid scintillation counting. The developed method was validated by analysing two samples from proficiency tests. In most of water samples (from rivers, rain, mineral bottled waters and tap waters) analysed, the activity values were lower or close to the minimum detectable activity (MDA) for our method which has a value of 0.6 Bq/l. However, the Ebro river samples had a mean activity around 3.6±0.6Bq/l. The nuclear power station of Asco, which is located on the banks of this river, can be a source of tritium production and introduction into the environment, so a more exhaustive study of these waters was carried out. Tritium activities in this river were a long way above the normative limit in Spain for waters intended for human consumption, which is 100 Bq/l

  20. Investigation of natural radioactivity level of the waters in Yunnan Province

    International Nuclear Information System (INIS)

    The authors report the investigation results of natural radioactivity level in river, lake, reservoir, spring, well, offshore water and tap water in Yunnan Province. There were totally 344 samples collected from 223 measuring points. The results show that the radioactivity level of varied water bodies of the province was within normal natural background

  1. Comparison Of Vented And Absolute Pressure Transducers For Water-Level Monitoring In Hanford Site Central Plateau Wells

    International Nuclear Information System (INIS)

    Automated water-level data collected using vented pressure transducers deployed in Hanford Site Central Plateau wells commonly display more variability than manual tape measurements in response to barometric pressure fluctuations. To explain this difference, it was hypothesized that vented pressure transducers installed in some wells are subject to barometric pressure effects that reduce water-level measurement accuracy. Vented pressure transducers use a vent tube, which is open to the atmosphere at land surface, to supply air pressure to the transducer housing for barometric compensation so the transducer measurements will represent only the water pressure. When using vented transducers, the assumption is made that the air pressure between land surface and the well bore is in equilibrium. By comparison, absolute pressure transducers directly measure the air pressure within the wellbore. Barometric compensation is achieved by subtracting the well bore air pressure measurement from the total pressure measured by a second transducer submerged in the water. Thus, no assumption of air pressure equilibrium is needed. In this study, water-level measurements were collected from the same Central Plateau wells using both vented and absolute pressure transducers to evaluate the different methods of barometric compensation. Manual tape measurements were also collected to evaluate the transducers. Measurements collected during this study demonstrated that the vented pressure transducers over-responded to barometric pressure fluctuations due to a pressure disequilibrium between the air within the wellbores and the atmosphere at land surface. The disequilibrium is thought to be caused by the relatively long time required for barometric pressure changes to equilibrate between land surface and the deep vadose zone and may be exacerbated by the restriction of air flow between the well bore and the atmosphere due to the presence of sample pump landing plates and well caps. The disequilibrium is likely limited to wells screened across the water table (i.e., open to the deep vadose zone) where the depth to water is large or a low-permeability layer occurs in the vadose zone. Such wells are a pathway for air movement between the deep vadose zone and land surface and this sustains the pressure disequilibrium between the well bore and the atmosphere for longer time periods. Barometric over-response was not observed with the absolute pressure transducers because barometric compensation was achieved by directly measuring the air pressure within the well. Users of vented pressure transducers should be aware of the over-response issue in certain Hanford Site wells and ascertain if it will affect the use of the data. Pressure disequilibrium between the well and the atmosphere can be identified by substantial air movement through the wellbore. In wells exhibiting pressure disequilibrium, it is recommended that absolute pressure transducers be used rather than vented transducers for applications that require precise automated determinations of well water-level changes in response to barometric pressure fluctuations.

  2. Effect of water level drawdown on decomposition in boreal peatlands

    Science.gov (United States)

    Straková, Petra; Penttilä, Timo; Laiho, Raija

    2010-05-01

    Plant litter production and decomposition are key processes in element cycling in most ecosystems. In peatlands, there has been a long-term imbalance between litter production and decay caused by high water levels (WL) and consequent anoxia. This has resulted in peatlands being a significant sink of carbon (C) from the atmosphere. However, peatlands are experiencing both "natural" (global climate change) and anthropogenic (ditching) changes that threaten their ability to retain this ecosystem identity and function. Many of these alterations can be traced back to WL drawdown, which can cause increased aeration, higher acidity, falling temperatures, and a greater probability of drought. Such changes are also associated with an increasing decomposition rate, and therefore a greater amount of C released back to the atmosphere. Yet studies about how the overall C balance of peatlands will be affected have come up with conflicting conclusions, demonstrating that the C store could increase, decrease, or remain static. A factor that has been largely overlooked is the change in litter type composition following persistent WL drawdown. It is the aim of our study, then, to help to resolve this issue. We studied the effects of short-term (ca. 4 years) and long-term (ca. 40 years) persistent WL drawdown on the decomposition of numerous types of above-ground and below-ground plant litters at three boreal peatland sites: bog, oligotrophic fen and mesotrophic fen. We thus believe that enough permutations have been created to obtain a good assessment of how each factor, site nutrient level, WL regime, and litter type composition, influences decomposition. We used the litter bag method to measure the decomposition rates: placed measured amounts of plant litter, or cellulose strips as a control, into closed mesh bags, and installed the bags in the natural environment for decomposition for each litter type for varying amounts of time. Following litter bag recovery, the litter was cleaned of excess debris and analyzed for changes in mass, enzyme activity, mesofauna presence, and microbial community composition, among other things. The experiment has a run-time of ten years, the results from the first two years are presented in the poster.

  3. Borehole sounding device with sealed depth and water level sensors

    Science.gov (United States)

    Skalski, Joseph C.; Henke, Michael D.

    2005-08-02

    A borehole device having proximal and distal ends comprises an enclosure at the proximal end for accepting an aircraft cable containing a plurality of insulated conductors from a remote position. A water sensing enclosure is sealingly attached to the enclosure and contains means for detecting water, and sending a signal on the cable to the remote position indicating water has been detected. A bottom sensing enclosure is sealingly attached to the water sensing enclosure for determining when the borehole device encounters borehole bottom and sends a signal on the cable to the remote position indicating that borehole bottom has been encountered.

  4. Response of bacterial community structure to seasonal fluctuation and anthropogenic pollution on coastal water of Alang-Sosiya ship breaking yard, Bhavnagar, India.

    Science.gov (United States)

    Patel, Vilas; Munot, Hitendra; Shouche, Yogesh S; Madamwar, Datta

    2014-06-01

    Bacterial community structure was analyzed from coastal water of Alang-Sosiya ship breaking yard (ASSBY), world's largest ship breaking yard, near Bhavnagar, using 16S rRNA gene sequencing (cultured dependent and culture independent). In clone libraries, total 2324 clones were retrieved from seven samples (coastal water of ASSBY for three seasons along with one pristine coastal water) which were grouped in 525 operational taxonomic units. Proteobacteria was found to be dominant in all samples. In pristine samples, Gammaproteobacteria was found to be dominant, whereas in polluted samples dominancy of Gammaproteobacteria has shifted to Betaproteobacteria and Epsilonproteobacteria. Richness and diversity indices also indicated that bacterial community in pristine sample was the most diverse followed by summer, monsoon and winter samples. To the best of knowledge, this is the first study describing bacterial community structure from coastal water of ASSBY, and it suggests that seasonal fluctuation and anthropogenic pollutions alters the bacterial community structure. PMID:24727696

  5. Influence of Closing Storm Surge Barrier on Extreme Water Levels and Water Exchange; The Limfjord, Denmark

    DEFF Research Database (Denmark)

    NØrgaard, JØrgen Quvang Harck; Bentzen, Thomas Ruby

    2014-01-01

    The Limfjord is the largest Danish estuary and is connected to both the North Sea in the west and the Kattegat in the east. The connection to the North Sea was formed in 1825 by a storm surge, and has since been kept open partly artificially. The debate about the climate changes and thereby the increased risk of flooding in the estuary has revitalized the discussion whether this connection should be closed. In this paper, it is shown by numerical simulation that the establishment of a storm surge barrier across Thyborøn Channel can significantly reduce the peak water levels in the central of the fjord. The reduction is obtained by blocking the ingoing flow with a sluice in due time before the storm surge peaks in the North Sea. In order to avoid problems with reduced water quality and salinity, the water exchange should be controlled by only keeping the sluice open for ingoing currents for the rest of days during the year. Depending on the effective cross-sectional area of the sluice, the depth-averaged salinity in the Limfjord remains status quo for cross-sectional areas of 500m2, whereas the salinity increases with up to 1.5 PSU for larger openings.

  6. Sulfur Isotope Systematics and the Link Between Fluctuating Sulfate Levels and P Recycling in a Low Sulfate, Permanently Anoxic Lake (Lake McCarrons, MN): Implications for the Precambrian Rise of Oxygen

    Science.gov (United States)

    Gomes, M. L.; Hurtgen, M. T.

    2009-12-01

    Seawater sulfate concentrations have been used to track the rise of oxygen in the Precambrian ocean-atmosphere system because the primary mode of sulfate delivery to the ocean is the oxidative weathering of sulfides on land. Ancient seawater sulfate concentrations have been inferred from the extent of sulfur (S) isotope fractionation incurred during bacterial sulfate reduction (BSR) where organisms preferentially utilize 32S (over 34S) in the process of reducing of sulfate to sulfide. Within this context, increased variability in ?34Spyrite values in Proterozoic (~2.3 Ga) sediments—along with a corresponding increase in the isotopic difference between sulfate and pyrite (?34S)—has been attributed to an increase in seawater sulfate concentrations (from 1 mM) and inferentially Earth-surface oxygen levels. However, most S isotope studies have been calibrated using modern marine sediments that contain sulfate-reducing bacteria that are adapted to the high concentration of sulfate in the modern ocean (~28mM). In order to better understand S isotope systematics within a low sulfate system and to improve our interpretive construct for S isotope results generated from ancient strata, we explore the magnitude of S isotope fractionations associated with microbial activity in the water column and sediments of a low sulfate (<300 µM), permanently anoxic lake in Minnesota (Lake McCarrons). Furthermore, we explore the link between fluctuating sulfate levels and phosphorus (P) recycling in low sulfate systems by conducting lab incubation experiments under low and varying sulfate concentrations using sediment collected from Lake McCarrons. The results indicate: (1) surface water sulfate levels are ~275 µM and fall to ~130 µM at the sediment-water interface; (2) the S isotope difference between surface water sulfate and bottom water sulfide is ~5‰ (?34S) while in situ S isotope fractionations associated with BSR at the sediment-water interface approach 35‰; (3) sulfate reduction rates in the upper 3 cm of organic carbon rich sediment are ~0.1 µM cm-3 d-1, an order of magnitude lower than those recorded under higher (modern marine) sulfate concentrations; and (4) sulfate concentrations influence the efficiency of P recycling (as determined via bag incubation experiments). Here, we suggest that an increase in sulfate levels at ~2.3 Ga, as indicated by larger ?34S values recorded in strata of this age, facilitated higher rates of BSR, enhanced P recycling and thus higher primary production within marine surface waters and contributed to the magnitude of the “Great Oxidation Event.”

  7. Water Hardness Level and ItAND#8217;s Health Effects

    Directory of Open Access Journals (Sweden)

    Necmettin Kocak

    2011-04-01

    Full Text Available Water hardness is a term used to define the number of ions contained in the water, especially quantity sulphate, carbonate salts of calcium and magnesium. This characteristis of water is a important quality in it’s use as drinking water, industrial water and service water. The temporary hardness level of water cames from bicarbonate salts of calcium and magnesium whereas chloride, sulphate, nitrate, phosphate, silicate salts of calcium and magnesium. In order to indicate the hardness level of water samples French Hardness Level is used in our country. There is a larger amounth of calcium and magnesium salts in hard water samples. These minerals have very important functions in the human body. In this study, the importance of hard water in terms of human health has been assessed under light of current information. The studies about the preventive role of hard water in cardiovascular diseases, cerebrovascular diseases, stroke and many types of cancer areviewed. These studies Express that higher levels of calcium and magnesium hard water provide a higher reduction in these disease. Water, which must be consumed as 2 liters per dayis very important for human life. Hard water contains a lot of the minerals that must be taker daily, especially calcium and magnesium. It’s advised that water for consumption to have medium hardness. The hardness level of water is an aesthetic quality. Thus, in populations having a taste for soft water, the effort of individuals to softer the network water provided by municipalities using different equipments, in addition to their preference of soft water in plastic or glass bottles for consumption could imply lack of benefit of hard water for population health and also bring out some risks in terms of water hygiene. [TAF Prev Med Bull 2011; 10(2.000: 187-192

  8. 1:750,000-scale static ground-water levels of Nevada

    U.S. Geological Survey, Department of the Interior — This data set consists of static ground-water levels for the State of Nevada based on a 1974 ground-water map (Rush, 1974) published by the Nevada Department of...

  9. Stochastic modeling of Lake Van water level time series with jumps and multiple trends

    Science.gov (United States)

    Aksoy, H.; Unal, N. E.; Eris, E.; Yuce, M. I.

    2013-06-01

    In the 1990s, water level in the closed-basin Lake Van located in the Eastern Anatolia, Turkey, has risen up about 2 m. Analysis of the hydrometeorological data shows that change in the water level is related to the water budget of the lake. In this study, stochastic models are proposed for simulating monthly water level data. Two models considering mono- and multiple-trend time series are developed. The models are derived after removal of trend and periodicity in the dataset. Trend observed in the lake water level time series is fitted by mono- and multiple-trend lines. In the so-called mono-trend model, the time series is treated as a whole under the hypothesis that the lake water level has an increasing trend. In the second model (so-called multiple-trend), the time series is divided into a number of segments to each a linear trend can be fitted separately. Application on the lake water level data shows that four segments, each fitted with a trend line, are meaningful. Both the mono- and multiple-trend models are used for simulation of synthetic lake water level time series under the hypothesis that the observed mono- and multiple-trend structure of the lake water level persist during the simulation period. The multiple-trend model is found better for planning the future infrastructural projects in surrounding areas of the lake as it generates higher maxima for the simulated lake water level.

  10. Stochastic modeling of Lake Van water level time series with jumps and multiple trends

    Directory of Open Access Journals (Sweden)

    H. Aksoy

    2013-06-01

    Full Text Available In the 1990s, water level in the closed-basin Lake Van located in the Eastern Anatolia, Turkey, has risen up about 2 m. Analysis of the hydrometeorological data shows that change in the water level is related to the water budget of the lake. In this study, stochastic models are proposed for simulating monthly water level data. Two models considering mono- and multiple-trend time series are developed. The models are derived after removal of trend and periodicity in the dataset. Trend observed in the lake water level time series is fitted by mono- and multiple-trend lines. In the so-called mono-trend model, the time series is treated as a whole under the hypothesis that the lake water level has an increasing trend. In the second model (so-called multiple-trend, the time series is divided into a number of segments to each a linear trend can be fitted separately. Application on the lake water level data shows that four segments, each fitted with a trend line, are meaningful. Both the mono- and multiple-trend models are used for simulation of synthetic lake water level time series under the hypothesis that the observed mono- and multiple-trend structure of the lake water level persist during the simulation period. The multiple-trend model is found better for planning the future infrastructural projects in surrounding areas of the lake as it generates higher maxima for the simulated lake water level.

  11. Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study

    OpenAIRE

    Luke Barbara; Fleming Lora E; Messing Rita; Backer Lorraine C; Manassaram Deana M; Monteilh Carolyn P

    2010-01-01

    Abstract Background Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL). Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The objective of this study was to assess methemoglobin levels and examine how various factors affect...

  12. Bath-tub vortex attenuation with the increase of in-vessel water level

    International Nuclear Information System (INIS)

    During the study of a bath-tub vortex formed in water flowing out through the hole in a vessel's bottom, a methodology was developed that enables controlling the change of in-vessel water level by continuous replenishment. The controlled rate of replenishment enables not only compensating for the loss of drained water and maintaining it at a constant level, but also increasing such a level. Enhancement of water level at different times after the formation of the bath-tub vortex leads to the gradual extinction of the vortex until its complete disappearance when a certain critical level of water in the vessel is achieved. A bath-tub vortex shape with a decrease of in-vessel water level and increase differs significantly. (paper)

  13. Global Climate and Sea Level ENDURING VARIABILITY AND RAPID FLUCTUATIONS OVER THE PAST 150,000 YEARS

    OpenAIRE

    Yusuke Yokoyama; Esat, Tezer M.

    2011-01-01

    Although climate variations and sea level changes are often discussed interchangeably, climate change need not always result in sea level change. Perturbations in Earth’s orbit cause major climate changes, and the resulting variations in the amount and distribution of solar radiation at ground level follow cycles lasting for thousands of years. Research done in the last decade shows that climate can change on centennial or shorter time scales. These more rapid changes appear to be related t...

  14. Fuzzy Control of Water Level and Temperature in Fish Eggs Breeding Tank with Different Sensor Inputs

    OpenAIRE

    Tarik Namas

    2013-01-01

    In this paper fuzzy logic principles are used to control the level and temperature of water in fish eggs breading tank. The control task aims to keep the water level and the water temperature in a tank within certain ranges, the temperature due to Newton’s law of cooling would drop down, and to keep it within limits, hot water is added, and cold water is drained. Sensors for temperature and level are used to give fuzzy input to the fuzzy controller which outputs the amount of opening in the...

  15. Analysis of the causes of price fluctuations of dairy products at individual levels of the product vertica

    Directory of Open Access Journals (Sweden)

    Z. Gebeltová

    2010-09-01

    Full Text Available The paper analyzes the reasons for the prices of milk and milk products in the Czech Republic for the period 2008 – 2009. In January 2008, the purchase price of raw milk was 10.08 CZK/l, and in the subsequent period it began to decline. At the end of 2008, the price was more than 3 crowns lower, and still the decrease continued. The research determined that the essential reason for the price fluctuations is the impact of the economic crisis. A substantial portion of the article was devoted to analyzing the behavior of supermarket chains toward their suppliers. It was discovered that even here there is a lot of room for the creation of pricing policy. Margin trading networks up to 25% of the delivered goods. Price negotiations affect the position papers in the manufacturing vertical. The power of suppliers and processors is based on the establishment of a strong integration unit. In the conclusion the author discusses possible future developments in price, sales policy, and the self-sufficiency of milk production in the Czech Republic. The paper was processed within the framework of the Research Project of MSM 6046070906 "The economics of Czech agricultural resources and their effective use within the framework of multifunctional agri-food systems".

  16. Challenge to high-activity-level water treatment by adsorbents

    International Nuclear Information System (INIS)

    There are over 280,000 tonnes of contaminated water in the damaged Fukushima Daiichi Nuclear Plant site in various tanks and barges and a large amount of contaminated water is now producing at the rate of several tonnes/day owing to inevitable cooling of the reactor cores. SARRY (Simplified Active Water Retrieve and Recovery System) and ALPS (Advanced Liquid Processing System) are installed to remove Cs and multi-elements respectively utilizing ion exchangers (zeolite, crystalline silicon titanate, and metal ferrocyanides) from contaminated water. The author continues efforts to find effective and selective adsorbents for Cs and Sr by measuring partition data, adsorption isotherms and adsorption rate referring with chemical structure elucidated from X-ray diffraction and SEM techniques. The obtained data are presented. (S. Ohno)

  17. Modelling water table levels to integrate wetland management and ecosystem functions

    Science.gov (United States)

    Acreman, M.; Bradford, R.

    2003-04-01

    The Somerset Levels and Moors (UK) contain a range of wetland types with different management regimes, including important areas of wet grassland habitats. A groundwater flow model, MODFLOW, is applied at the field-scale to predict spatial and temporal variations in water table levels. The results are used for a range of applications, including the impact of controlled water levels for the conflicting water requirements of agriculture and biodiversity and to assist the study of microbial activity that controls methane production.

  18. Coastal hazards projections on the U.S. West Coast using a dynamic water level modeling approach

    Science.gov (United States)

    Barnard, P.; Erikson, L. H.; Foxgrover, A. C.; O'Neill, A.

    2014-12-01

    Many studies of future coastal flooding vulnerability consider sea level rise and tides only, typically applying a bath-tub type approach that omits key physical-forcing factors that elevate flood levels during storm events such as waves, surge and fluvial discharge. Here we present a new modeling approach that considers all the relevant factors that contribute to elevated water levels for open coast and embayment settings along the U.S. West Coast during projected 21stcentury storms. The Coastal Storm Modeling System (CoSMoS) is a numerical modeling system developed to predict coastal flooding due to both SLR and plausible 21st century storms for active-margin settings like the U.S. West Coast. CoSMoS applies a predominantly deterministic framework that encompasses large geographic scales (100s to 1000s of kilometers) yet models flood extents to a local resolution (2 m) so that storm related changes in water levels at the shore can be resolved. In the latest iteration of CoSMoS applied to San Francisco Bay, efforts were made to incorporate water level fluctuations in response to trapped coastal waves, low pressure systems, ocean swell energy penetrating through the Golden Gate, locally wind-generated waves, and backflow induced by river discharge. The end product is a web-based tool (www.prbo.org/ocof) where users can assess variations in flood extent, maximum flood depth, maximum current velocities and wave heights in response to a number of potential SLR and storm combinations, providing direct support for adaptation and management decisions. Future efforts in Southern California will feature a dynamic coastal DEM that evolves over decadal time scales to provide updated boundary conditions for future storm simulations.

  19. Investigation of spatio-temporal water level and mass oscillations by using satellite gravimetry, altimetry and thermal data in Caspian Sea

    Science.gov (United States)

    Moradi, A.; de Viron, O.; Metivier, L.

    2012-12-01

    As Caspian Sea does not communicate with the world oceans, its dynamics are very different from the global water. Although -as for the world ocean- its level presents regular annual oscillations, estimations from last century and new more precise measurements shows large interannual fluctuations. Changes in the Caspian Sea water volume are investigated using space altimetry, whereas the GRACE satellite gravimetry mission allows monitoring the change of the surface mass distribution. Under the hypothesis that the change in water mass is the only cause of gravity change, it is possible to convert the mass distribution change into volume change, using a steric equation for the sea water. Combinations of multi-mission gridded altimetry data from AVISO with mono mission time series were used in order to analyze the local fluctuations of the lake, revealing a significant tilt between north and south. Large differences in the surface mass distribution rate of change in the basin and in the lake are evidenced in the GRACE data, as well as small differences in phase, which are due to delayed snow melting. Ignoring the short-term changes in water level due to winds, the main reason to cause periodic spatial water level disuniformity is spatial disuniformity in water density. Steric effect was calculated by interfering 2 factors of temperature and salinity. Steric anomaly maps show that it is able to change water level up to 17 cm. As the northern part of the lake has the least salinity in summers the largest effect would be expected to occur in the northern part, but the opposite is observed, probably due to the fact that this part is the shallowest. For the steric anomaly the lake presents spatially variations of 3 cm in winter but 7 cm in the summers. Generally, the largest steric induced fluctuations are observed in the middle of the lake, mostly in the north and east parts of the lake center. We used altimetry and space gravity data jointly, in order to build an improved and more coherent picture of the time space variation of the lake level and mass distribution. ;

  20. Neural Network Model for Prediction of Ground Water Level in Metropolitan Considering Rainfall-Runoff as a Parameter

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar

    2013-07-01

    Full Text Available In metropolitan area the ground water is the important resource of drinking water. To preserve the ground water level several rain water harvesting techniques are implemented now a days. A neural network model has been developed for ground water level prediction. Various models developed before for ground water level prediction with artificial neural network methodology. Most of these models these models consider rainfall and current ground water level as input parameter. This model considers rainfall-runoff as an important factor which represents the performance of rain water harvesting techniques in urban area. So this model predicts the ground water level with the effect of rain water harvesting techniques.

  1. Neural Network Model for Prediction of Ground Water Level in Metropolitan Considering Rainfall-Runoff as a Parameter

    OpenAIRE

    Sanjeev Kumar; Ajay Indian; Zubair Khan

    2013-01-01

    In metropolitan area the ground water is the important resource of drinking water. To preserve the ground water level several rain water harvesting techniques are implemented now a days. A neural network model has been developed for ground water level prediction. Various models developed before for ground water level prediction with artificial neural network methodology. Most of these models these models consider rainfall and current ground water level as input parameter. This model considers...

  2. Establishing solar water disinfection as a water treatment method at household level

    OpenAIRE

    Regula Meierhofer

    2006-01-01

    1.1 billion People worldwide do not have access to safe drinking water and therefore are exposed to a high risk for diarrhoeal diseases. As a consequence, about 6,000 children die each day of dehydration due to diarrhoea. Adequate water treatment methods and safe storage of drinking water, combined with hygiene promotion, are required to prevent the population without access to safe drinking water from illness and death. Solar water disinfection (SODIS) is a new water treatment to be applied ...

  3. Dual-Level Material and Psychological Assessment of Urban Water Security in a Water-Stressed Coastal City

    Directory of Open Access Journals (Sweden)

    Yajing Huang

    2015-04-01

    Full Text Available The acceleration of urbanization and industrialization has been gradually aggravating water security issues, such as water shortages, water pollution, and flooding or drought disasters and so on. Water security issues have become a great challenge to urban sustainable development. In this context, we proposed a dual-level material and psychological assessment method to assess urban water security. Psychological security coefficients were introduced in this method to combine material security and residents’ security feelings. A typical water-stressed coastal city in China (Dalian was chosen as a case study. The water security status of Dalian from 2010 to 2012 was analysed dynamically. The results indicated that the Dalian water security statuses from 2010 to 2012 were basically secure, but solutions to improve water security status and solve water resource problems are still required. This dual-level material and psychological assessment for urban water security has improved conventional material assessment through the introduction of psychological security coefficients, which can benefit decision-making for urban water planning, management and protection.

  4. Radioactivity levels in surface water of lakes around Izmir / Turkey

    International Nuclear Information System (INIS)

    Radioactivity presents in surface continental waters is mainly due to the presence of radioactive elements in the earth's crust, other artificial radionuclides have appeared due to such human activities as nuclear power plants, nuclear weapons testing and manufacture and use of radioactive sources It is well known that natural radionuclides can be effective as tracers for the different processes controlling the distribution of elements among dissolved and particulate phases in aquatic systems. The detection of high radionuclide concentrations was proposed as a public health problem in several areas and consequently studies into the risks of radionuclides were started in the 2000s. Especially, these radioactive substances in groundwater are an unwanted and involuntary risk factor from natural sources, not artificial sources. These radioactive substances include uranium, radon found in uranium series, and other radioactive substances such as radium and gross alpha. Uranium present in rock, soil, and natural materials, and is found in small quantities in air, water, and food that people always contact. In this project, lake water samples were collected from three lakes around Izmir-Turkey. In surface lake water samples, pH, mV and conductivity values were measured and alkaline content was determined titrimetrically. The uranium concentrations in the lake water samples were measured using uranium analyzer. The radioactivity concentrations related to gross radium isotopes, gross-? and gross-? activities in the surface lake water were determined. The correlation among some parameters for water samples and concentrations of uranium, activity concentration of gross radium isotopes, gross alpha and gross beta radioactivity are also discussed

  5. Layers of air in the water beneath the floating fern salvinia are exposed to fluctuations in pressure.

    Science.gov (United States)

    Mayser, Matthias J; Barthlott, Wilhelm

    2014-12-01

    Superhydrophobic, hierarchically structured, technical surfaces (Lotus-effect) are of high scientific and economic interest because of their remarkable properties. Recently, the immense potential of air-retaining superhydrophobic surfaces, for example, for low-friction transport of fluids and drag-reducing coatings of ships has begun to be explored. A major problem of superhydrophobic surfaces mimicking the Lotus-effect is the limited persistence of the air retained, especially under rough conditions of flow. However, there are a variety of floating or diving plant and animal species that possess air-retaining surfaces optimized for durable water-repellency (Salvinia-effect). Especially floating ferns of the genus Salvinia have evolved superhydrophobic surfaces capable of maintaining layers of air for months. Apart from maintaining stability under water, the layer of air has to withstand the stresses of water pressure (up to 2.5 bars). Both of these aspects have an application to create permanent air layers on ships' hulls. We investigated the effect of pressure on air layers in a pressure cell and exposed the air layer to pressures of up to 6 bars. We investigated the suppression of the air layer at increasing pressures as well as its restoration during decreases in pressure. Three of the four examined Salvinia species are capable of maintaining air layers at pressures relevant to the conditions applying to ships' hulls. High volumes of air per surface area are advantageous for retaining at least a partial Cassie-Baxter-state under pressure, which also helps in restoring the air layer after depressurization. Closed-loop structures such as the baskets at the top of the "egg-beater hairs" (see main text) also help return the air layer to its original level at the tip of the hairs by trapping air bubbles. PMID:24925548

  6. Human Impacts on Tides Overwhelm the Effect of Sea Level Risee on Extreme Water Levels in the Rhine-Meuse Delta

    Science.gov (United States)

    Hoitink, T.; Vellinga, N.; Hoekstra, P.; Van Der Vegt, M.; Zhang, W.

    2014-12-01

    Mean sea level rise receives ample attention in the literature. However, peak water levels, which are most important for flood vulnerability and salinity intrusion in tidal river networks, may not be linearly related with mean surface levels. To quantify tidal and subtidal water level changes and to link these changes to human intervention, 70 years of water level data for the Rhine-Meuse tidal river network is analysed using a variety of statistical methods. Using a novel parameterization of probability density functions, mean high and low water levels are examined, and extreme water levels are investigated by applying the combined Mann-Kendall and Pettitt tests to find trends and trend changes. Tidal water levels are studied based on harmonic analysis. Results show that the mean water levels throughout the system rise with the same pace as the mean sea level. However, high and low water levels do not show the same increase, and the spatial variability in decadal trends in high- and low water levels is high. High water and low water extremes generally decrease. Both the extreme water level analysis and the harmonic analysis display significant trend breaks in 1970, 1981 and 1997. These breaks can be attributed to the closure of the Haringvliet estuary, the removal of sluices and the removal of a dam, respectively, which radically alter the tidal motion. These results demonstrate that the direct human influence on the tidal motion can overwhelm the effect of mean sea level rise on water level extremes.

  7. Design and Implementation of a Water Level Controller using Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Namrata Dey

    2013-06-01

    Full Text Available This paper analyzes the effectiveness of water level control using fuzzy logic. The water level in the tank is sensed using transistor switching principle. The level sensed is fed to the PIC16 microcontroller. The user provides the set point to the microcontroller through serial communication using the COM development port software, Terminal. It computes the error as the difference between the set point and the process variable. The fuzzy logic programmed in the microcontroller is applied which controls the water level in the tank using the drain and the feed pumps. Once the set point has been reached, the message along with the present level is sent back through serial communication to the user interface on a PC. Thus, the water level in the tank is controlled according to the set point given by the user. The implementation of a fuzzy level controller has many applications such as boiler drum level control, reverse osmosis plant, demineralisation plant etc.

  8. Global Climate and Sea Level ENDURING VARIABILITY AND RAPID FLUCTUATIONS OVER THE PAST 150,000 YEARS

    Directory of Open Access Journals (Sweden)

    Yusuke Yokoyama

    2011-06-01

    Full Text Available Although climate variations and sea level changes are often discussed interchangeably, climate change need not always result in sea level change. Perturbations in Earth’s orbit cause major climate changes, and the resulting variations in the amount and distribution of solar radiation at ground level follow cycles lasting for thousands of years. Research done in the last decade shows that climate can change on centennial or shorter time scales. These more rapid changes appear to be related to modifications in ocean circulation initiated during the last glacial period either by injections of fresh meltwater or huge ice discharges into the North Atlantic. When first detected, these rapid climate changes were characterized as episodes decoupled from any significant change in sea level. New data clearly show a direct connection between climate and sea level, and even more surprising, this link may extend to times of glacial-interglacial transitions and possibly also to interglacials. The full extent of this sea level/climate coupling is unknown and is the subject of current research.

  9. Natural radiation level in drinking water in Homs city

    International Nuclear Information System (INIS)

    In this study, radon concentrations were measured at the sources of drinking water and in some tap water in houses in Homs County. All measurements showed that concentrations are within the international allowed limits and there is no big difference in concentration between the sources and the houses. Also total alpha/beta and radium-226 content were measured in the samples of the sources and the houses using liquid scintillation counter. All measurements showed that concentrations are within the international allowed limits. (authors)

  10. Hydrology and water quality of Shell Lake, Washburn County, Wisconsin, with special emphasis on the effects of diversion and changes in water level on the water quality of a shallow terminal lake

    Science.gov (United States)

    Juckem, Paul F.; Robertson, Dale M.

    2013-01-01

    Shell Lake is a relatively shallow terminal lake (tributaries but no outlets) in northwestern Wisconsin that has experienced approximately 10 feet (ft) of water-level fluctuation over more than 70 years of record and extensive flooding of nearshore areas starting in the early 2000s. The City of Shell Lake (City) received a permit from the Wisconsin Department of Natural Resources in 2002 to divert water from the lake to a nearby river in order to lower water levels and reduce flooding. Previous studies suggested that water-level fluctuations were driven by long-term cycles in precipitation, evaporation, and runoff, although questions about the lake’s connection with the groundwater system remained. The permit required that the City evaluate assumptions about lake/groundwater interactions made in previous studies and evaluate the effects of the water diversion on water levels in Shell Lake and other nearby lakes. Therefore, a cooperative study between the City and U.S. Geological Survey (USGS) was initiated to improve the understanding of the hydrogeology of the area and evaluate potential effects of the diversion on water levels in Shell Lake, the surrounding groundwater system, and nearby lakes. Concerns over deteriorating water quality in the lake, possibly associated with changes in water level, prompted an additional cooperative project between the City and the USGS to evaluate efeffects of changes in nutrient loading associated with changes in water levels on the water quality of Shell Lake. Numerical models were used to evaluate how the hydrology and water quality responded to diversion of water from the lake and historical changes in the watershed. The groundwater-flow model MODFLOW was used to simulate groundwater movement in the area around Shell Lake, including groundwater/surface-water interactions. Simulated results from the MODFLOW model indicate that groundwater flows generally northward in the area around Shell Lake, with flow locally converging toward the lake. Total groundwater inflow to Shell Lake is small (approximately 5 percent of the water budget) compared with water entering the lake from precipitation (83 percent) and surface-water runoff (13 percent). The MODFLOW model also was used to simulate average annual hydrologic conditions from 1949 to 2009, including effects of the removal of 3 billion gallons of water during 2003–5. The maximum decline in simulated average annual water levels for Shell Lake due to the diversion alone was 3.3 ft at the end of the diversion process in 2005. Model simulations also indicate that although water level continued to decline through 2009 in response to local weather patterns (local drought), the effects of the diversion decreased after the diversion ceased; that is, after 4 years of recovery (2006–9), drawdown attributable to the diversion alone decreased by about 0.6 ft because of increased groundwater inflow and decreased lake-water outflow to groundwater caused by the artificially lower lake level. A delayed response in drawdown of less than 0.5 ft was transmitted through the groundwater-flow system to upgradient lakes. This relatively small effect on upgradient lakes is attributed in part to extensive layers of shallow clay that limit lake/groundwater interaction in the area. Data collected in the lake indicated that Shell Lake is polymictic (characterized by frequent deep mixing) and that its productivity is limited by the amount of phosphorus in the lake. The lake was typically classified as oligotrophic-mesotrophic in June, mesotrophic in July, and mesotrophic-eutrophic in August. In polymictic lakes like Shell Lake, phosphorus released from the sediments is not trapped near the bottom of the lake but is intermittently released to the shallow water, resulting in deteriorating water quality as summer progresses. Because the productivity of Shell Lake is limited by phosphorus, the sources of phosphorus to the lake were quantified, and the response in water quality to changes in phosphorus inputs were evaluated by means of eutrophication models. During

  11. Applying Water-Level Difference Control to Central Arizona Project

    Science.gov (United States)

    The Central Arizona Project (CAP) has been supplying Colorado River water to Central Arizona for roughly 25 years. The CAP canal is operated remotely with a Supervisory Control and Data Acquisition (SCADA) System. Gate position changes are made either manually or through the use of automatic control...

  12. Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Luke Barbara

    2010-10-01

    Full Text Available Abstract Background Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL. Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The objective of this study was to assess methemoglobin levels and examine how various factors affected methemoglobin levels during pregnancy. We also examined whether differences in water use practices existed among pregnant women based on household drinking water source of private vs. public supply. Methods A longitudinal study of 357 pregnant women was conducted. Longitudinal regression models were used to examine changes and predictors of the change in methemoglobin levels over the period of gestation. Results Pregnant women showed a decrease in methemoglobin levels with increasing gestation although Conclusion Pregnant women potentially exposed to nitrate levels primarily below the MCL for drinking water were unlikely to show methemoglobin levels above the physiologic normal. Water use practices such as the use of treatment devices to remove nitrates varied according to water source and should be considered in the assessment of exposure to nitrates in future studies.

  13. Classical and Quantal Descriptions of Small Amplitude Fluctuations Around Equilibriums in the Two-Level Pairing Model

    OpenAIRE

    Tsue, Y.; Providencia, C.; Da Providencia, J.; Yamamura, M.

    2006-01-01

    Various classical counterparts for the two-level pairing model in a many-fermion system are presented in the Schwinger boson representation. It is shown that one of the key ingredients giving the classical descriptions for quantal system is the use of the various trial states besides the $su(2)\\otimes su(2)$-coherent state, which may be natural selection for the two-level pairing model governed by the $su(2)\\otimes su(2)$-algebra. It is pointed out that the fictitious behavi...

  14. Response to an oral calcium load in nephrolithiasis patients with fluctuating parathyroid hormone and ionized calcium levels

    OpenAIRE

    Gomes S.A.; Lage A.; Lazaretti-Castro M.; Vieira J.G.H.; Heilberg I.P.

    2004-01-01

    the response to an oral calcium load test was assessed in 17 hypercalciuric nephrolithiasis patients who presented elevated parathyroid hormone (PTH) irrespective of the ionized calcium (sCa2+) levels. Blood samples were collected at baseline (0 min) and at 60 and 180 min after 1 g calcium load for serum PTH, total calcium, sCa2+, and 1.25(OH)2D3 determinations. According to the sCa2+ level at baseline, patients were classified as normocalcemic (N = 9) or hypercalcemic (N = 8). Six healthy su...

  15. Sub-tidal water-level oscillations in the Mandovi estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Vijith, V.

    2013-01-01

    Using water-level data collected at six locations during March–April 2003 in the main channel of the Mandovi estuary, one of the 50 odd estuaries on the west coast of India, we describe the nature of variability of water level in the estuary...

  16. Investigation of natural radioactivity level of the waters in Guangxi Zhuangzu Autonomous Region

    International Nuclear Information System (INIS)

    This paper reports the investigation results of natural radioactivity level in river, lake reservoir, spring, well and tap water in Guangxi Zhuangzu Autonomous Region. There were totally 194 samples collected from 143 measuring points. The results show that the radioactivity level of varied water bodies of the region was within normal natural background

  17. Water Scarcity and Allocation in the Tarim Basin: Decision Structures and Adaptations on the Local Level

    Directory of Open Access Journals (Sweden)

    Niels Thevs

    2011-01-01

    Full Text Available The Tarim River is the major water source for all kinds of human activities and for the natural ecosystems in the Tarim Basin, Xinjiang, China. The major water consumer is irrigation agriculture, mainly cotton. As the area under irrigation has been increasing ever since the 1950s, the lower and middle reaches of the Tarim are suffering from a water shortage. Within the framework of the Water Law and two World Bank projects, the Tarim River Basin Water Resource Commission was founded in 1997 in order to foster integrated water resource management along the Tarim River. Water quotas were fixed for the water utilization along the upstream and downstream river stretches. Furthermore, along each river stretch, quotas were set for water withdrawal by agriculture and industry and the amount of water to remain for the natural ecosystems (environmental flow. Furthermore, huge investments were undertaken in order to increase irrigation effectiveness and restore the lower reaches of the Tarim River. Still, a regular water supply for water consumers along the Tarim River cannot be ensured. This paper thus introduces the hydrology of the Tarim River and its impacts on land use and natural ecosystems along its banks. The water administration in the Tarim Basin and the water allocation plan are elaborated upon, and the current water supply situation is discussed. Finally, the adaptations made due to issues of water allocation and water scarcity on the farm level are investigated and discussed.

  18. Radiation levels during shutdown in boiling water reactors

    International Nuclear Information System (INIS)

    To perform a realistic dose assessment, a data collection program was initiated to determine what balance of plant systems contribute to operational exposure. Six utilities that operate boiling water reactors participated in the program. As a result of the study, systems or components that were most important with respect to crud-based radiation were identified. The study focused on the following systems: residual heat removal, spent fuel cooling and cleanup, transverse in-core probes, flow and equipment drains, feed, reactor water cleanup, and steam systems. During the study, additional components or systems where no crud-based radiation was expected were identified, e.g., control rod drive pumps, scram discharge volumes, and certain condensate system equipment. It is expected that this information will help utility operators limit crud-producing radiation doses by providing prior knowledge of potential and buildup

  19. Projections of extreme water level events for atolls in the western Tropical Pacific

    Science.gov (United States)

    Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

    2014-12-01

    Conditions that lead to extreme water levels and coastal flooding are examined for atolls in the Republic of the Marshall Islands based on a recent field study of wave transformations over fringing reefs, tide gauge observations, and wave model hindcasts. Wave-driven water level extremes pose the largest threat to atoll shorelines, with coastal levels scaling as approximately one-third of the incident breaking wave height. The wave-driven coastal water level is partitioned into a mean setup, low frequency oscillations associated with cross-reef quasi-standing modes, and wind waves that reach the shore after undergoing high dissipation due to breaking and bottom friction. All three components depend on the water level over the reef; however, the sum of the components is independent of water level due to cancelling effects. Wave hindcasts suggest that wave-driven water level extremes capable of coastal flooding are infrequent events that require a peak wave event to coincide with mid- to high-tide conditions. Interannual and decadal variations in sea level do not change the frequency of these events appreciably. Future sea-level rise scenarios significantly increase the flooding threat associated with wave events, with a nearly exponential increase in flooding days per year as sea level exceeds 0.3 to 1.0 m above current levels.

  20. Analysing water level strategies to reduce soil subsidence in Dutch peat meadows

    OpenAIRE

    Querner, E. P.; Jansen, P. C.; Akker, J. J. H.; Kwakernaak, C.

    2012-01-01

    The survival of peat meadows in the Netherlands is threatened by soil subsidence, less favourable conditions for farming and rising costs of water management. To support policy-making, a study examined possible future strategies for these meadows in the west of the Netherlands. Future scenarios with different water level strategies and climate scenarios were modelled with the SIMGRO regional hydrological model. The analysis focused on water level control strategies, in combination with subsur...

  1. TIME SERIES METHODS FOR WATER LEVEL FORECASTING OF DUNGUN RIVER IN TERENGGANU MALAYSIA

    OpenAIRE

    SITI HAJAR ARBAIN; ANTONI WIBOWO

    2012-01-01

    Due to climate change and global warming, the possibility of floods may increase to occur in Malaysia. Water level forecasting are important for the water catchment management in particular for flood warning systems. The aim of this study is to predict water level with input variables monthly rainfall and rate of evaporation takenfrom the same catchment at Dungun River, Terengganu-Malaysia, using ARIMA and Artificial Neural Network (ANN). The process of pre-processing data has been made to th...

  2. Preliminary Assessment of Flourine Level of Spring and Stream Water in South West Nigeria

    OpenAIRE

    Olakunle Moses Makanjuola

    2012-01-01

    Four water samples from each of spring and stream in some locations across South-West, Nigeria, were analyzed for their fluoride levels and some other quality parameters. The samples coded 101, 202, 303, 404 representing spring water and 505, 606, 707, 808 representing stream water were analyzed for fluoride levels using Ion Selective Electrode method (ISE) while other quality parameters such as calcium, chloride, alkalinity, hardness and pH were determined using standard methods. The results...

  3. The level of environmental noise affects the physiological performance of Glycine max under water deficit

    Scientific Electronic Library Online (English)

    Suzana Chiari, Bertolli; Gustavo M., Souza.

    Full Text Available Plants in natural environments are subjected to a multitude of environmental cues. However, studies addressing physiological analyzes are usually focused on the isolation of a stress factor, making it difficult to understand plants behavior in their extremely complex natural environments. Herein, we [...] analyzed how environmental variability (noise) may influence physiological processes of Glycine max under water deficit conditions. The plants were kept in a greenhouse (semi-controlled environment - E SC) and in a growth chamber (controlled environment - E C) under two water regime conditions (100 and 30% of replacement of the water lost by evapotranspiration) for 30 days. The environmental variability was daily monitored with automatic sensors to record temperature, humidity, and irradiance. The physiological responses were analyzed by leaf gas exchanges, chlorophyll fluorescence, biomembrane integrity, and growth parameters. The results showed that water deficiency caused significant reductions in the physiological parameters evaluated. However, the environment with high variability (E SC) caused more extensive damages to biomembranes, regardless the water regime likely compromising physiological efficiency. The lower variability of E C promoted higher efficiency of total biomass production in both water regimes compared to the E SC. Therefore, our results support the hypothesis that more variable environmental conditions can limit the growth of Glycine max in response to the fluctuation of resources, therefore amplifying the effect of water deficit.

  4. Classical and Quantal Descriptions of Small Amplitude Fluctuations around Equilibriums in the Two-Level Pairing Model

    Science.gov (United States)

    Tsue, Y.; Providência, C.; Providência, J. D.; Yamamura, M.

    2007-05-01

    Various classical counterparts to the two-level pairing model in a many-fermion system are presented in the Schwinger boson representation. It is shown that one of the key ingredients giving the classical descriptions for quantal systems is the use of various trial states in addition to the su(2) otimes su(2)-coherent state, which may be a natural selection for the two-level pairing model governed by the su(2) otimes su(2)-algebra. It is pointed out that a spurious behavior such as a sharp phase transition can be avoided by using the other states including the su(2) otimes su(1,1)- and su(1,1) otimes su(1,1)-coherent states. This contrasts with the situation regarding the usual Hartree-Fock-Bogoliubov and quasi-particle random phase approximations applied to the original fermion system, which yield a sharp phase transition.

  5. Classical and Quantal Descriptions of Small Amplitude Fluctuations Around Equilibriums in the Two-Level Pairing Model

    CERN Document Server

    Tsue, Y; Providência, J; Yamamura, M

    2006-01-01

    Various classical counterparts for the two-level pairing model in a many-fermion system are presented in the Schwinger boson representation. It is shown that one of the key ingredients giving the classical descriptions for quantal system is the use of the various trial states besides the $su(2)\\otimes su(2)$-coherent state, which may be natural selection for the two-level pairing model governed by the $su(2)\\otimes su(2)$-algebra. It is pointed out that the fictitious behavior like the sharp phase transition can be avoided by using the other states such as the $su(2)\\otimes su(1,1)$- and the $su(1,1)\\otimes su(1,1)$-coherent states, while the sharp phase transition appears in the usual Hartree-Fock-Bogoliubov and the quasi-particle random phase approximations in the original fermion system.

  6. Classical and quantal descriptions of small amplitude fluctuations around equilibriums in the two-level pairing model

    International Nuclear Information System (INIS)

    Various classical counterparts to the two-level pairing model in a many-fermion system are presented in the Schwinger boson representation. It is shown that one of the key ingredients giving the classical descriptions for quantal systems is the use of various trial states in addition to the su(2) x su(2)-coherent state, which may be a natural selection for the two-level pairing model governed by the su(2) x su(2)-algebra. It is pointed out that a spurious behavior such as a sharp phase transition can be avoided by using the other states including the su(2) x su(1, 1)- and su(1, 1) x su(1, 1)-coherent states. This contrasts with the situation regarding the usual Hartree-Fock-Bogoliubov and quasi-particle random phase approximations applied to the original fermion system, which yield a sharp phase transition. (author)

  7. The study of chloroform levels during water disinfection by chlorination reference to health risk in drinking water of karachi (pakistan)

    International Nuclear Information System (INIS)

    This study presents the levels of the chloroform formation during water disinfiction treatment by chlorination with the subsequent formation of by-products like trihalomethanes (THMs) are formed. These THMs in drinking water are found in the form of chloroform, bromodichloromethane, Chlorodibromomethane and bromoform. Out of these four compounds chloroform is the major culprit and Contribute 9.0% of the total THMs concentration (I). Therefore the present work was focused on the Estimation of levels of chloroform in the drinking water samples of Karachi city (Pakistan) by using Bootstrapping statistical technique with regards to the average cancer risk in the community. (author)

  8. Structured hydrological analysis for targeting fallow evaporation to improve water productivity at the irrigation system level

    OpenAIRE

    Khan, S; M. M. Hafeez; Rana, T.; Mushtaq, S.

    2007-01-01

    This paper provides results of an application of a holistic systematic approach of water accounting using remote sensing and GIS coupled with ground water modeling to evaluate water saving options by tracking non-beneficial evaporation in the Liuyuankou Irrigation System (LIS) of China. Groundwater rise is a major issue in the LIS, where groundwater levels have risen alarmingly close to the ground surface (within 1 m) near the Yellow River. The lumped water balance analysis showed high fallow...

  9. Relationship of drinking water disinfectants to plasma cholesterol and thyroid hormone levels in experimental studies.

    OpenAIRE

    Revis, N. W.; Mccauley, P.; Bull, R.; Holdsworth, G.

    1986-01-01

    The effects of drinking water containing 2 or 15 ppm chlorine (pH 6.5 and 8.5), chlorine dioxide, and monochloramine on thyroid function and plasma cholesterol were studied because previous investigators have reported cardiovascular abnormalities in experimental animals exposed to chlorinated water. Plasma thyroxine (T4) levels, as compared to controls, were significantly decreased in pigeons fed a normal or high-cholesterol diet and drinking water containing these drinking water disinfectant...

  10. The Effect of Water Level on The Effectiveness of Sediment Flushing

    Directory of Open Access Journals (Sweden)

    S. Suripin

    2012-10-01

    Full Text Available This research is focused on determining the effective flushing water level in pressure flushing activity at storage sedimen based on the hydraulic physical model test in the laboratory. The effective water level is the elevation of water level in sediment flushing which result in the highest concentration of sediment scours. Effective flushing water level is the elevation of water level near the top layer of sediment deposit which can trigger the erosion of the top layer of sediment so that it creates a maximum scours. That elevation is known as Effective Flushing Water Level (EFWL. This research was conducted in the laboratory using Wonogiri Reservoir prototype, with scale model of 1:66.67. The model operated without inflow, started from control water level (CWL .and lowered gradually by operating the flushing gates. The gates were operated of a = 2.50 cm. The flushing implementation was repeated with variation of sediment thickness Hs=1.50; 3.00; 3.75 and 4.50 cm. The water level, sediment concentration, flushing discharge, and the flow velocity in the upstream of the gates were observed every 1.50 cm lowered of water level. Coal dust was used in this research to substitute sediment material. The result of this research is expected to be used as an initial consideration of effective sediment flushing in Wonogiri reservoir protoype in order to reduce the capacity loss of the reservoir due to sedimentation , or in other words to extend the life time plan of reservoir. doi: http://dx.doi.org/10.12777/ijwr.2.2.2012.20-31 [ How to cite this article: Atmodjo, P. S., & Suripin, S. (2012. The Effect of Water Level on The Effectiveness of Sediment Flushing. International Journal of Waste Resources (IJWR, 2(2, 20-31. doi: http://dx.doi.org/10.12777/ijwr.2.2.2012.20-31

  11. Evaluation of the Dynamic Velocity Effect for Steam Generator Wide Range Water Level

    International Nuclear Information System (INIS)

    The measurement of Steam Generator (SG) water level is based upon pressure differential of the level transmitter. As shown in Fig. 1, if the location of a lower tap is in the downcomer region, a deviation between the indicated level and the actual level occurs. This phenomenon is called 'velocity effect' or 'dynamic effect.' This effect needs to be addressed to obtain a more accurate SG water level. Korean Utility Requirements Document (KURD) requires Downcomer Velocity Effect (DVE) to be quantified and to be considered in the instrument requirements. In this paper, DVE occurred through downcomer will be evaluated for SG wide range (WR) level for OPR1000

  12. Effect of Pressure, Water Depth and Water Flow Rate on Oxygen Saturation Level in Activated Sludge Process

    Directory of Open Access Journals (Sweden)

    Nabil N. Atta

    2011-01-01

    Full Text Available Problem statement: The role of aeration in activated sludge process is to provide oxygen to microorganisms as they assimilate the organic carbon compounds and digest a portion of them to carbon dioxide and water, sulfate and nitrate compounds. The water aeration equipment used in this process consumes as much as 60-80% of total power requirements in modern wastewater treatment plants. Approach: The objective of this study is to enhance the oxygen transfer in aeration tank in activated sludge process by increasing pressure inside the part of aeration tank to increase the saturation level of dissolved oxygen in wastewater. The diffuser cap model is the experimental model which was used to show the effect of increasing pressure on oxygen transfer level. Three cases were considered, the first used without diffuser cap, the second with diffuser cap and the third with diffuser cap and plastic strips. Results: Obtained results show that in case of using the model with diffuser cap enhanced the oxygen level by about 5% than in case of without diffuser cap while that of adding plastic strips enhanced the oxygen level by about 7%. The variation of water flow showed that increasing water flow rate from 1-2 L min-1 decreased the oxygen saturation level by about 6%. Furthermore, increasing water depth from 15-60 cm increased the oxygen level by about 40%. Conclusion: The diffuser cap model showed that the increase of pressure and water depth increased the dissolved oxygen level while increasing water flow rate decreased the dissolved oxygen level.

  13. Fuzzy logic control of water level in advanced boiling water reactor

    International Nuclear Information System (INIS)

    The feedwater control system in the Advanced Boiling Water Reactor (ABWR) is more challenging to design compared to other control systems in the plant, due to the possible change in level from void collapses and swells during transient events. A basic fuzzy logic controller is developed using a simplified ABWR mathematical model to demonstrate and compare the performance of this controller with a simplified conventional controller. To reduce the design effort, methods are developed to automatically tune the scaling factors and control rules. As a first step in developing the fuzzy controller, a fuzzy controller with a limited number of rules is developed to respond to normal plant transients such as setpoint changes of plant parameters and load demand changes. Various simulations for setpoint and load demand changes of plant performances were conducted to evaluate the modeled fuzzy logic design against the simplified ABWR model control system. The simulation results show that the performance of the fuzzy logic controller is comparable to that of the Proportional-Integral (PI) controller, However, the fuzzy logic controller produced shorter settling time for step setpoint changes compared to the simplified conventional controller

  14. Water levels in the Yucca Mountain area, Nevada, 1990--91

    International Nuclear Information System (INIS)

    Water levels were monitored in 27 wells in the Yucca Mountain area, Nevada during 1990--91. Twelve wells were monitored periodically, generally on a monthly basis, and 15 wells representing 24 intervals were monitored hourly. All wells monitor water levels in Tertiary volcanic rocks, except one that monitors levels in paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes and pressure transducers; steel-tape measurements were corrected for mechanical stretch, thermal expansion, and borehole deviation to obtain precise water-level altitudes. Water-level altitudes in the Tertiary volcanic rocks ranged from about 728 meters above sea level east of Yucca Mountain to about 1,035 meters above sea level north of Yucca Mountain. Water-level altitudes in the well monitoring the Paleozoic carbonate rocks varied between 752 and 753 meters above sea level during 1990--91. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  15. An electrical impedance sensor for water level measurements in air–water two-phase stratified flows

    International Nuclear Information System (INIS)

    We report a design of an optimized ring-type impedance sensor for water level measurements in air–water stratified flows through horizontal pipes. The ring-type sensor is optimized in view of the sensor linearity. In order to determine an optimal electrode and gap size of a ring-type sensor which generates a linear relationship between the impedance (resistance and/or reactance) and the water level, systematic numerical calculations are performed, and a ring-type impedance sensor of electrode width-to-diameter ratio 0.25 and gap-to-diameter ratio 0.2 has been selected as optimal. Lab-scale static experiments have been conducted to verify the sensor performance in terms of the linearity. Finally, this proposed sensor is installed in a horizontal loop 40 mm in diameter and roughly 5200 mm in length and measures water levels for various stratified flow conditions. The comparisons of water level measurements between the proposed sensor and the high-speed camera images post-processed by the edge detection scheme show that the maximum deviation in dimensionless water level is roughly 0.037, which corresponds to 1.5 mm over the range 40 mm. (paper)

  16. Oxygen Saturation and Hemoglobin Level in the Muscles of Hypertensive Patients during Exercise in Water.

    Science.gov (United States)

    Sakakima, Harutoshi; Ijiri, Kosei; Iwai, Maki; Oowatashi, Akihiko; Morimoto, Norio; Komiya, Seturo; Tsunoda, Naoya; Sudo, Akiharu

    2004-01-01

    To clarify whether exercise therapy in a water environment is appropriate therapy for hypertensive patients, we investigated oxygen saturation and hemoglobin level in the vastus medialis muscle using a laser tissue blood oxygen monitor. Seven hypertensive patients (52 to 77 years of age, hypertensive group) and five healthy volunteers (44 to 69 years of aged, control group) participated in this study. Subjects maintained resting postures for about 5 minutes each in a standing position, a sitting position on a chair, a lying position out of water, and a position in water below the navel and to the chest level. Subjects performed flexion/extension movement of the knee joint (30 times/min) in and out of water. Oxygen saturation level (SaO2), oxygenated hemoglobin level (HbO2), deoxygenated hemoglobin level (HbD), and total tissue hemoglobin level (HbT) were measured in the muscle tissue. Blood pressure (BP) and pulse rate (PR) were monitored simultaneously. In the hypertensive group, SaO2 in muscle tissue in water was significantly increased compared with that in a standing position out of water (pstanding position (p<0.05). In both groups, the ratios of HbD and HbO2 (O2/D ratio) was significantly increased in water environment compared with that out of water (p<0.05). The O2 /D ratio, which indicates oxygenation within the tissue, increased during exercise in water in the hypertensive group. This study demonstrated that oxygen saturation in the muscles of the hypertensive group was lower than that in controls out of water, but the level was increased in water. Our findings suggest that water provides a good exercise environment for hypertensive patients from the perspective of oxygen saturation in hypertensive muscle tissue. PMID:25792935

  17. The west African mangrove: an indicator of sea-level fluctuations and regional climate changes during the last deglaciation

    International Nuclear Information System (INIS)

    The review of modern and late Quaternary pollen data recording the mangrove evolution in West Africa shows that littoral and deep-sea sediments have registered different signals. The first one gives evidence for past sea-level variations from ca. 12,000 B.P. to ca. 5,000 B.P. The second one records the first widespread response of tropical forest ecosystems to the last deglaciation step and enhanced monsoonal rains at ca. 9,500 B.P. (authors)

  18. Measurement of low radioactive levels of radioiodine in surface waters

    International Nuclear Information System (INIS)

    Two methods which are complementary or alternative to the method specified in the ISO 10703/1970 standard were developed. In the first alternative, NaOH is used for the final adjustment of the basic pH. The amount of residue in the desiccation is lower than that for the carbonates in the standard method, using the same volumes and characteristics of the water. After adjusting the pH to 9 in order to filter the solution two sub-samples can be obtained. From the solid fraction, after successive stages of purification by washing in concentrated nitric acid, an AgI precipitate can be obtained and assayed by gamma spectrometry and/or beta emission counting. The soluble fraction, plus the different solutions produced during the previous purification, can be reconditioned together to an acid pH, typically 1-2, and evaporated to dryness, producing in this case a residue similar to that obtained by applying the section of the ISO standard 10703/1970 without iodine retention. The second alternative consists of conditioning the original water sample with NaHSO3 to maintain the iodine in the ionic form, which will subsequently be adsorbed during vigorous stirring or flow through an AG1 1 x 8 100-200 mesh chloride-form resin. The supernatant and the resin are dried, allowing both sub-samples to be assayed by high resolution gamma spectrometry

  19. Design and Implementation of a Water Level Controller using Fuzzy Logic

    OpenAIRE

    Namrata Dey; Ria Mandal; Monica Subashini, M.

    2013-01-01

    This paper analyzes the effectiveness of water level control using fuzzy logic. The water level in the tank is sensed using transistor switching principle. The level sensed is fed to the PIC16 microcontroller. The user provides the set point to the microcontroller through serial communication using the COM development port software, Terminal. It computes the error as the difference between the set point and the process variable. The fuzzy logic programmed in the microcontroller is applied whi...

  20. Modeling Caspian Sea water level oscillations under different scenarios of increasing atmospheric carbon dioxide concentrations

    OpenAIRE

    Roshan GholamReza; Moghbel Masumeh; Grab Stefan

    2012-01-01

    Abstract The rapid rise of Caspian Sea water level (about 2.25 meters since 1978) has caused much concern to all five surrounding countries, primarily because flooding has destroyed or damaged buildings and other engineering structures, roads, beaches and farm lands in the coastal zone. Given that climate, and more specifically climate change, is a primary factor influencing oscillations in Caspian Sea water levels, the effect of different climate change scenarios on future Caspian Sea levels...

  1. Sensitivity and uncertainty analysis for crop water footprint accounting at a basin level

    Science.gov (United States)

    Zhuo, L.; Mekonnen, M. M.; Hoekstra, A. Y.

    2013-12-01

    Water footprint has been recognized as a comprehensive indicator in water management to evaluate the human pressure on water resources from either production or consumption perspectives. The agricultural sector in particular crop production takes the largest share of the global water footprint. Water footprint of producing unit mass of a crop (m3/ ton) is normally expressed by single volumetric numbers referring to an average value for certain areas and periods. However, the divergence in crop water footprint accounts from different studies, primarily due to the input data quality, may confuse water users and managers. The study investigates the output sensitivity and uncertainty of the green (rainfall) and blue (irrigation water) crop water footprint to key input variables (reference evapotranspiration (ETo), precipitation (PR), crop coefficient (Kc) and crop calendar (D)) at a basin level. A grid-based daily water balance model was applied to compute water footprints of four major crops - maize, rice, soybean and wheat - in the Yellow River basin for 1996-2005 at a 5 by 5 arc minute resolution. Sensitivities of the yearly crop water footprints to individual input variability were assessed by the one-at-a-time (';sensitivity curve') method. Uncertainty in crop water footprint to input uncertainties were quantified through Monte Carlo simulations for selected years 1996 (wet), 2000 (dry) and 2005 (average). Results show that the crop water footprint is most sensitive to ETo and Kc, followed by D and PR. Blue water footprints were more sensitive than green water footprints to input variability. Interestingly, the smaller the annual blue water footprint, the higher its sensitivity to PR, ETo and Kc variability. The uncertainties in total crop water footprints to combined uncertainties in four key input variables was less than × 30% for total water footprints at 95% confidence level. The sensitivity and uncertainty level of crop water footprints also differs with crop types. In the current study, soybean had the highest sensitivity and the largest uncertainty in water footprints. The study provides the first detailed estimate of the output sensitivity and uncertainty in crop water footprint accounting to input variability and uncertainties. Providing the uncertainty ranges in combination with the estimated crop water footprint can undoubtedly increase the output reliability and adaptability in water management.

  2. Individual two level fluctuators in the tunneling conductance of Al/AlOx/Al Josephson junctions for superconducting qubits

    Science.gov (United States)

    Nugroho, Christopher; Orlyanchik, Vladimir; van Harlingen, Dale

    2014-03-01

    Two level system (TLS) defects in AlOx tunnel barriers can lead to low-frequency 1 / f critical current noise and losses in coherent superconducting circuits. Understanding the nature of these defects and how to eliminate them are critical in order to achieve ultra-long coherence times. We present measurements of the tunneling conductance of ultrasmall, A quantum-limited tunneling at lower temperatures. Tracking the TLS switching rates as a function of the applied voltage bias provides an estimate of the TLS charge dipole moment. In some quantum tunneling limited TLSs we have observed a non-equilibrium enhancement of the switching rates that cannot be explained by simple dissipative heating of the TLSs. Further investigations into these TLS defects may lead to the identification of their physical origins and strategies to eliminate them. Research funded by the Intelligence Advanced Research Projects Activity (IARPA).

  3. A Screening-Level Hydroeconomic Model of South Florida Water Resources System

    Science.gov (United States)

    Mirchi, A.; Watkins, D. W., Jr.; Flaxman, M.; Wiesmann, D.

    2014-12-01

    South Florida's water resources management is characterized by system-wide tradeoffs associated with maintaining the ecological integrity of natural environments such as the Everglades while meeting the water demands of the agricultural sector and growing urban areas. As these tradeoffs become more pronounced due to pressures from climate change, sea level rise, and population growth, it will be increasingly challenging for policy makers and stakeholders to reach consensus on water resources management objectives and planning horizons. A hydroeconomic optimization model of south Florida's water resources system is developed to incorporate the value of water for preserving ecosystem services alongside water supplies to the Everglades Agricultural Area and urban areas. Results of this screening-level network flow model facilitate quantitative analysis and provide insights for long-term adaptive management strategies for the region's water resources.

  4. Determining return water levels at ungauged coastal sites: a case study for northern Germany

    Science.gov (United States)

    Arns, Arne; Wahl, Thomas; Haigh, Ivan D.; Jensen, Jürgen

    2015-04-01

    We estimate return periods and levels of extreme still water levels for the highly vulnerable and historically and culturally important small marsh islands known as the Halligen, located in the Wadden Sea offshore of the coast of northern Germany. This is a challenging task as only few water level records are available for this region, and they are currently too short to apply traditional extreme value analysis methods. Therefore, we use the Regional Frequency Analysis (RFA) approach. This originates from hydrology but has been used before in several coastal studies and is also currently applied by the local federal administration responsible for coastal protection in the study area. The RFA enables us to indirectly estimate return levels by transferring hydrological information from gauged to related ungauged sites. Our analyses highlight that this methodology has some drawbacks and may over- or underestimate return levels compared to direct analyses using station data. To overcome these issues, we present an alternative approach, combining numerical and statistical models. First, we produced a numerical multidecadal model hindcast of water levels for the entire North Sea. Predicted water levels from the hindcast are bias corrected using the information from the available tide gauge records. Hence, the simulated water levels agree well with the measured water levels at gauged sites. The bias correction is then interpolated spatially to obtain correction functions for the simulated water levels at each coastal and island model grid point in the study area. Using a recommended procedure to conduct extreme value analyses from a companion study, return water levels suitable for coastal infrastructure design are estimated continuously along the entire coastline of the study area, including the offshore islands. A similar methodology can be applied in other regions of the world where tide gauge observations are sparse.

  5. Seven years of external control of fluoride levels in the public water supply in Bauru, Sao Paulo, Brazil

    Scientific Electronic Library Online (English)

    Marilia Afonso Rabelo, BUZALAF; Camila Mascarenhas, MORAES; Kelly Polido Kaneshiro, OLYMPIO; Juliano Pelim, PESSAN; Larissa Tercilia, GRIZZO; Thelma Lopes, SILVA; Ana Carolina, MAGALHAES; Rodrigo Cardoso de, OLIVEIRA; Sonia, GROISMAN; Irene, RAMIRES.

    2013-01-01

    Full Text Available Fluoridation of the public water supplies is recognized as among the top ten public health achievements of the twentieth century. However, the positive aspects of this measure depend on the maintenance of fluoride concentrations within adequate levels. Objective To report the results of seven years [...] of external control of the fluoride (F) concentrations in the public water supply in Bauru, SP, Brazil in an attempt to verify, on the basis of risk/benefit balance, whether the levels are appropriate. Material and Methods From March 2004 to February 2011, 60 samples were collected every month from the 19 supply sectors of the city, totaling 4,641 samples. F concentrations in water samples were determined in duplicate, using an ion-specific electrode (Orion 9609) coupled to a potentiometer after buffering with TISAB II. After the analysis, the samples were classified according to the best risk-benefit adjustment. Results Means (±standard deviation) of F concentrations ranged between 0.73±0.06 and 0.81±0.10 mg/L for the different sectors during the seven years. The individual values ranged between 0.03 and 2.63 mg/L. The percentages of the samples considered “low risk” for dental fluorosis development and of “maximum benefit” for dental caries prevention (0.55-0.84 mg F/L) in the first, second, third, fourth, fifth, sixth, and seventh years of the study were 82.0, 58.5, 37.4, 61.0, 89.9, 77.3, and 72.4%, respectively, and 69.0% for the entire period. Conclusions Fluctuations of F levels were found in the public water supply in Bauru during the seven years of evaluation. These results suggest that external monitoring of water fluoridation by an independent assessor should be implemented in cities where there is adjusted fluoridation. This measure should be continued in order to verify that fluoride levels are suitable and, if not, to provide support for the appropriate adjustments.

  6. Predicted impacts of future water level decline on monitoring wells using a ground-water model of the Hanford Site

    International Nuclear Information System (INIS)

    A ground-water flow model was used to predict water level decline in selected wells in the operating areas (100, 200, 300, and 400 Areas) and the 600 Area. To predict future water levels, the unconfined aquifer system was stimulated with the two-dimensional version of a ground-water model of the Hanford Site, which is based on the Coupled Fluid, Energy, and Solute Transport (CFEST) Code in conjunction with the Geographic Information Systems (GIS) software package. The model was developed using the assumption that artificial recharge to the unconfined aquifer system from Site operations was much greater than any natural recharge from precipitation or from the basalt aquifers below. However, artificial recharge is presently decreasing and projected to decrease even more in the future. Wells currently used for monitoring at the Hanford Site are beginning to go dry or are difficult to sample, and as the water table declines over the next 5 to 10 years, a larger number of wells is expected to be impacted. The water levels predicted by the ground-water model were compared with monitoring well completion intervals to determine which wells will become dry in the future. Predictions of wells that will go dry within the next 5 years have less uncertainty than predictions for wells that will become dry within 5 to 10 years. Each prediction is an estimate based on assumed future Hanford Site operating conditions and model assumptions

  7. [Effect of external condition on the static migration and release of dibutylphthalate in the soil of the fluctuating zone of the Three Gorges Reservoir to the overlying water].

    Science.gov (United States)

    Song, Jiao-yan; Mu, Zhi-jian; Wang, Qiang; Yang, Zhi-dan; Wang, Fa

    2015-01-01

    In order to understand the environmental behavior of the organic pollutants Dibutyl-phthalate (DBP) in fluctuating zone soil, the migration and release processes of DBP in the fluctuating zone of the Three Gorges Reservoir to the overlying water and the impacts of temperature, light, coexistence phthalate-bis (2-ethylhexyl)-ester (DEHP), microbial activity on the process were studied using static flooding method. The results showed that DBP migrated from the soil to the overlying water in the early days after flooding, and the release process of DBP was divided into two phases: one was the quick release with a relatively short releasing time and a rapid releasing rate; the other was the slow release with a relatively long releasing time and a slow releasing rate. The slow release was a major speed control step, which could be well fitted by two-compartment first-order kinetics. In the interim (12 d) after flooding, the capacity of release reached a maximum, the DBP released from the soil into the water migrated from the water to the soil again after continued flooding, and eventually the content of DBP in soil and water reached equilibrium in the later period after flooding. The intensity of DBP releasing into the overlying water and the rapid releasing rate increased, while the slow releasing rate decreased when the temperature increased. The concentrations of DBP released into the water were different with different light sources. The concentration of DBP in the overlying water with treatment of natural light was higher than those with treatment of ultraviolet light UVB, UVA. After the amount of DBP in the overlying water reached the maximum, the content of DBP in the overlying water decreased relatively faster under the ultraviolet light than under the natural light. The largest release content of DBP and the time reached the largest release content were different with different oxygen content in the overlying water. Overall, the higher oxygen content in the overlying water, the higher content of DBP in the overlying water. The time when the concentration of DBP in overlying water reached the maximum was on the 8th day after flooding in the high oxygen and low oxygen studies, while the time was on the 12th day in natural study. When the phthalate-bis (2-ethylhexyl)-ester(DEHP) co-existed in the soil, there would be some significant influence on the release of DBP. After DEHP addition in the soil, it could release more DBP than the control, and both the rapid releasing rate and slow releasing rate were bigger than those of the control. The microbial activity had some impacts on the process. However, the effect was not obvious. After adding microbial activity inhibitor, the content of migrated DBP was slightly lower than that of the control. PMID:25898658

  8. DATA QUALIFICATION REPORT: WATER-LEVEL DATA FROM THE NYE COUNTY EARLY WARNING DRILLING PROGRAM

    International Nuclear Information System (INIS)

    The objective of this work is to evaluate unqualified, water-level data gathered under the Nye County Early Warning Drilling Program (EWDP) and to determine whether the status of the data should be changed to ''qualified'' data in accordance with AP-SIII.2Q (Qualification of Unqualified Data and the Documentation of Rationale for Accepted Data). The corroboration method (as defined in Attachment 2 of AP-SIII.2Q) was implemented to qualify water-level data from Nye County measurements obtained directly from the Nye County Nuclear Waste Repository Program Office (NWRPO). Comparison of United States Geological Survey (USGS) measurements contained in DTN GS990608312312.003 with the Nye County water-level data has shown that the differences in water-level altitudes for the same wells are significantly less than 1 meter. This is an acceptable finding. Evaluation and recommendation criteria have been strictly applied to qualify Nye County measurements of water levels in selected wells measured by the USGS. However, the process of qualifying measured results by corroboration also builds confidence that the Nye County method for measurement of water levels is adequate for the intended use of the data (which is regional modeling). Therefore, it is reasonable to extend the term of ''qualified'' to water-level measurements in the remaining Nye County Phase I wells on the basis that the method has been shown to produce adequate results for the intended purpose of supporting large-scale modeling activities for the Yucca Mountain Project (YMP). The Data Qualification Team recommends the Nye County, water-level data contained in Appendix D of this report be designated as ''qualified''. These data document manual measurements of water-levels in eight (8) EWDP Phase I drillholes that were obtained prior to the field installation of continuous monitoring equipment

  9. Radar Based Flow and Water Level Forecasting in Sewer Systems : a danisk case study

    DEFF Research Database (Denmark)

    Thorndahl, SØren; Rasmussen, Michael R.

    2009-01-01

    This paper describes the first radar based forecast of flow and/or water level in sewer systems in Denmark. The rainfall is successfully forecasted with a lead time of 1-2 hours, and flow/levels are forecasted an additional ½-1½ hours using models describing the behaviour of the sewer system. Both radar data and flow/water level model are continuously updated using online rain gauges and online in-sewer measurements, in order to make the best possible predictions. The project show very promising results, and show large potentials, exploiting the existing water infrastructure in future climate changes.

  10. Recent reduction in the water level of Lake Victoria has created more habitats for Anopheles funestus

    Directory of Open Access Journals (Sweden)

    Futami Kyoko

    2008-07-01

    Full Text Available Abstract Background The water level of Lake Victoria has fallen more than 1.5 m since 1998, revealing a narrow strip of land along the shore. This study determined whether the recent drop in the water level has created additional breeding grounds for malaria vectors. Methods The recent and past shorelines were estimated using landmarks and a satellite image. The locations of breeding habitats were recorded using a GPS unit during the high and low lake water periods. GIS was used to determine whether the breeding habitats were located on newly emerged land between the new and old shorelines. Results Over half of the breeding habitats existed on newly emerged land. Fewer habitats for the Anopheles gambiae complex were found during the low water level period compared to the high water period. However, more habitats for Anopheles funestus were found during the high water level period, and they were all located on the newly emerged land. Conclusion The recent reduction in water level of Lake Victoria has increased the amount of available habitat for A. funestus. The results suggest that the water drop has substantially affected the population of this malaria vector in the Lake Victoria basin, particularly because the lake has a long shoreline that may harbour many new breeding habitats.

  11. Fluctuating micro-heterogeneity in water - tert-butyl alcohol mixtures and lambda-type divergence of the mean cluster size with phase transition-like multiple anomalies

    CERN Document Server

    Banerjee, Saikat; Bagchi, Biman

    2014-01-01

    Water - tert-butyl alcohol (TBA) binary mixture exhibits a large number of thermodynamic and dynamic anomalies. These anomalies are observed at surprisingly low TBA mole fraction, with $x_{\\text{TBA}} \\approx 0.03 - 0.07$. We demonstrate here that the origin of the anomalies lies in the local structural changes that occur due to self-aggregation of TBA molecules. We observe a percolation transition of the TBA molecules at $x_{\\text{TBA}} \\approx 0.05$. We note that "islands" of TBA clusters form even below this mole fraction, while a large spanning cluster emerges above that mole fraction. At this percolation threshold, we observe a lambda-type divergence in the fluctuation of the size of the largest TBA cluster, reminiscent of a critical point. Alongside, the structure of water is also perturbed, albeit weakly, by the aggregation of TBA molecules. There is a monotonic decrease in the tetrahedral order parameter of water, while the dipole moment correlation shows a weak non-linearity. Interestingly, water mol...

  12. Reduction in fluoride levels in rinse water effluent from zircaloy component pickling

    International Nuclear Information System (INIS)

    Pickled zircaloy fuel tubes and components were being rinsed in running water, resulting in some carry-over of F- from the pickling solution to the rinse water. Reduction of F- level in the rinse water to environmentally acceptable level has been achieved by introducing a neutralising step between the stages of pickling and water rinsing. After large scale trials at Nuclear Fuel Complex (NFC), Hyderabad ammonium bicarbonate solution was found to be suitable for neutralisation of the acid carry-over from the pickling bath. The products of neutralisation (such as ammonium fluoride and ammonium zirconyl fluoro carbonate) are water soluble, leaving no residue on zircaloy. F- having thus been collected in the neutralising solution, the rinse water at the next stage is almost free from it. While the conventional approach in water treatment has been to remove F- from the contaminated water, in the NFC method contamination of water is prevented by neutralising the source of contamination. The neutralising solution is being periodically removed and lime treated to precipitate as insoluble fluoride land then disposed to solar evaporation ponds within NFC. This simple and less expensive process has been found to have the advantages of a fifty fold reduction in the volume of effluent to be lime treated for disposal and a fifty fold reduction in the F- level in rinse water. Saving in equipment and manpower have been achieved wquipment and manpower have been achieved while meeting environmental requirements. (author). 8 refs

  13. Study of emergency-action levels for light water reactors

    International Nuclear Information System (INIS)

    An emergency action level (EAL) is an observation or judgment that forms the basis for declaring an emergency status at a nuclear generating facility. There are four graded emergency category classifications which indicate an increasing potential for offsite radiological impact. Each emergency category is normally associated with an implementation procedure that outlines the preplanned actions that the emergency director will undertake. Thus a transient which causes a system or parameter to reach an EAL will also cause a transition of the normal station organization to an emergency organization. This transition will include an augmentation of the basic shift staff in order to support the corrective and mitigative actions of the nuclear reactor operators. In this regard, the major purpose of EALs is to provide an early indication of potential problems. Ideally, the ensuing response of the emergency organization will prevent a propagation of errors or failures that could result in serious consequences

  14. Solvating atomic level fine-grained proteins in supra-molecular level coarse-grained water for molecular dynamics simulations.

    Science.gov (United States)

    Riniker, Sereina; Eichenberger, Andreas P; van Gunsteren, Wilfred F

    2012-08-01

    Simulation of the dynamics of a protein in aqueous solution using an atomic model for both the protein and the many water molecules is still computationally extremely demanding considering the time scale of protein motions. The use of supra-atomic or supra-molecular coarse-grained (CG) models may enhance the computational efficiency, but inevitably at the cost of reduced accuracy. Coarse-graining solvent degrees of freedom is likely to yield a favourable balance between reduced accuracy and enhanced computational speed. Here, the use of a supra-molecular coarse-grained water model that largely preserves the thermodynamic and dielectric properties of atomic level fine-grained (FG) water in molecular dynamics simulations of an atomic model for four proteins is investigated. The results of using an FG, a CG, an implicit, or a vacuum solvent environment of the four proteins are compared, and for hen egg-white lysozyme a comparison to NMR data is made. The mixed-grained simulations do not show large differences compared to the FG atomic level simulations, apart from an increased tendency to form hydrogen bonds between long side chains, which is due to the reduced ability of the supra-molecular CG beads that represent five FG water molecules to make solvent-protein hydrogen bonds. But, the mixed-grained simulations are at least an order of magnitude faster than the atomic level ones. PMID:22797564

  15. Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap System

    OpenAIRE

    Cochrane, T. A.; Arias, M. E.; Piman, T.

    2014-01-01

    The rapid rate of water infrastructure development in the Mekong basin is a cause for concern due to its potential impact on fisheries and downstream natural ecosystems. In this paper we analyse the historical water levels of the Mekong River and Tonle Sap system by comparing pre and post 1991 daily observations from six stations along the Mekong mainstream from Chiang Sean (northern Laos), to Stung Treng (Cambodia), and the Prek Kdam station on the Tonle Sa...

  16. Estimation method of water level behavior in the case of large pressure change in a BWR

    International Nuclear Information System (INIS)

    In a BWR, coolant of core and upper plenum involves so much void volume that free surface level change at downcomer is conspicuous owing to increase and decrease of void volume influenced by pressure change. When mass balance in a reactor vessel becomes non-equilibrium due to steam valve stuck open or feedwater pump trip, difference between liquid level and mixture level becomes very large because of void increased due to depressurization. Therefore, it is very difficult to estimate changes in water level after void exclusion by isolation valve closure etc. So a new parameter ''effective increased void volume'' was contrived to estimate water level in the occurrance of above mentioned phenomena, as a result of consideration about relation between discharged mass and reactor pressure. Degree of water level change under initial operating conditions and reactor pressure change can be estimated by using this parameter. (author)

  17. Understanding the connection of extreme water levels to mortality in the megacity Dhaka

    Science.gov (United States)

    Thiele-Eich, Insa; Burkart, Katrin; Simmer, Clemens

    2015-04-01

    To quantitatively assess the impact of extreme water levels on a local scale we study both low and high water levels and their connection to mortality in the megacity Dhaka. Dhaka is currently threatened by a range of natural hazards such as earth quakes, tropical cyclones and - on an almost annual basis - flooding . Flooding in the megacity is largely determined by the close proximity to the confluence of the Ganges and Brahmaputra rivers upstream as well as the conjunction with the Meghna river further downstream. The risk of flooding is aggravated through rapid urbanization and concurrent encroachment on retention areas, as well as increasing problems with both the natural and man-made drainage system. A growing population, continuing urbanization and climate change are all expected to worsen the situation in Dhaka. This prompted us to study historical trends in extreme water levels using over 100 years of daily water level data with respect to trends in frequency, magnitude and duration, focusing on rare but particularly high-risk events using extreme-value theory. In a further step, the complex link between water levels and mortality are studied using a distributed lag non-linear model with mortality data available on a daily basis for a five-year period (2003-2007). Our analysis suggests that water levels have indeed changed over the course of the past century. While the magnitude and duration of average flood events decreased, the frequency of extreme flood events has increased. Low water levels have also changed, with a significant decrease in the annual minimum water level when comparing the time periods 1909-1939 and 1979-2009. Results further indicate that for the period of 2003-2007, which entails two major flood events in 2004 and 2007, high water levels do not lead to a significant increase in relative mortality, which indicates a good level of adaptation and capacity to cope with flooding. However, following low water levels, an increase in mortality could be found. This is particularly alarming as low water levels have continuously decreased over the past 100 years. Thus, to ensure the population is capable of coping with future climate change, we stress the importance of not only continuing and improving the current adaptation measures for flooding, but to also prepare the population for drought events.

  18. Incorporation of GIS Based Program into Hydraulic Model for Water Level Modeling on River Basin

    Directory of Open Access Journals (Sweden)

    Hadi Memarian

    2012-01-01

    Full Text Available Water resources management usually requires that hydraulic, ecological, and hydrological models be linked. The Hy- drologic Engineering Center River Analysis System (HEC-RAS hydraulic model and the Hydrologic Engineering Center Geospatial River Analysis System (HEC-GEORAS, imitates flow and water profiles in the Neka river basin’s downstream flood plain. Hydrograph phases studied during the flood seasons of 1986-1999 and from 2002-2004 were used to calibrate and verify the hydraulic model respectively. Simulations of peak flood stages and hydrographs’ evaluations are congruent with studies and observations, with the former showing mean square errors between 4.8 - 10 cm. HECRAS calculations and forecast flood water levels. Nash-Sutcliffe effectiveness (CR3 is more than 0.92 along with elevated levels of water which were created with some effectiveness (CR5 of 0.94 for the validation period. The coupled two models show good performance in the water level modeling.

  19. Trends in water level and flooding in Dhaka, Bangladesh and their impact on mortality.

    Science.gov (United States)

    Thiele-Eich, Insa; Burkart, Katrin; Simmer, Clemens

    2015-02-01

    Climate change is expected to impact flooding in many highly populated coastal regions, including Dhaka (Bangladesh), which is currently among the fastest growing cities in the world. In the past, high mortality counts have been associated with extreme flood events. We first analyzed daily water levels of the past 100 years in order to detect potential shifts in extremes. A distributed lag non-linear model was then used to examine the connection between water levels and mortality. Results indicate that for the period of 2003-2007, which entails two major flood events in 2004 and 2007, high water levels do not lead to a significant increase in relative mortality, which indicates a good level of adaptation and capacity to cope with flooding. However, following low water levels, an increase in mortality could be found. As our trend analysis of past water levels shows that minimum water levels have decreased during the past 100 years, action should be taken to ensure that the exposed population is also well-adapted to drought. PMID:25648177

  20. Trends in Water Level and Flooding in Dhaka, Bangladesh and Their Impact on Mortality

    Directory of Open Access Journals (Sweden)

    Insa Thiele-Eich

    2015-01-01

    Full Text Available Climate change is expected to impact flooding in many highly populated coastal regions, including Dhaka (Bangladesh, which is currently among the fastest growing cities in the world. In the past, high mortality counts have been associated with extreme flood events. We first analyzed daily water levels of the past 100 years in order to detect potential shifts in extremes. A distributed lag non-linear model was then used to examine the connection between water levels and mortality. Results indicate that for the period of 2003–2007, which entails two major flood events in 2004 and 2007, high water levels do not lead to a significant increase in relative mortality, which indicates a good level of adaptation and capacity to cope with flooding. However, following low water levels, an increase in mortality could be found. As our trend analysis of past water levels shows that minimum water levels have decreased during the past 100 years, action should be taken to ensure that the exposed population is also well-adapted to drought.

  1. Nimbus-6/SCAMS Level 2 Water Vapor and Temperature V001

    National Aeronautics and Space Administration — The Nimbus-6 Scanning Microwave Spectrometer (SCAMS) Level 2 data product contains water vapor and temperature profiles. The SCAMS was designed to map tropospheric...

  2. HIRDLS/Aura Level 3 Water Vapor (H2O) Zonal Fourier Coefficients V007

    National Aeronautics and Space Administration — The "HIRDLS/Aura Level 3 Water Vapor (H2O) Zonal Fourier Coefficients" version 7 data product (H3ZFCH2O) contains the entire mission (~3 years) of HIRDLS data...

  3. Effects of radiation heat transfer for prediction of water temperature and level in spent fuel pit

    International Nuclear Information System (INIS)

    In order to predict water temperature of the spent fuel pit (SFP) of nuclear power plants after shutdown of its cooling systems, a prediction system with a one-region model was developed based on three-dimensional (3D) thermal-hydraulic behavior calculated by using the CFD software, FLUENT 6.3.26. In the prediction system, decay heat calculated by using the burn-up calculation software, ORIGEN 2.2, and the previously proposed correlation for evaporation heat fluxes from the water surface to air were used. The prediction system was extended to calculate water temperature and level during loss of all AC power supplies under natural convection of air flow and the calculated results were verified using measured values from the Fukushima Daiichi Nuclear Power Station. This prediction system was introduced a conservative heat transfer model which ignored radiation heat fluxes that contained uncertain emissivity. Therefore, in this, study, we used a non-conservative heat transfer model including radiation heat fluxes with relatively large emissivity and we calculated effects of radiation heat fluxes on the water temperature and level to investigate uncertainties of the prediction system. As a result, we found radiation heat fluxes affected the decreasing rate of the water level but did not directly affect the water temperature. Then we did sensitivity calculations to obtain decay heat and evaporation heat flux which gave good agreement with the measured decreasing rate of the water level and water temperature, respectively. (author)

  4. Determination of Trace Level Triclosan in Water by Online Preconcentration and HPLC-UV Diode Array

    Science.gov (United States)

    An online high performance liquid chromatography (HPLC) method for the detection and quantification of trace levels of triclosan in water is discussed. Triclosan, an anti-bacterial agent, and related compounds have been shown to reach municipal waste waters through the disposal ...

  5. Prediction of design water level due to storm surge at teh Seogwipo coastal zone in Korea

    OpenAIRE

    Rok, M. S.; Man, Y. S.; Whan, K. J.; Jin, H. S.

    2013-01-01

    Seogwipo coastal region is known to develop coast tourist attractions and expand its harbor facilities, but this region is also more likely to get damaged by typhoons since it is affected by most of the typhoons coming into the Korean Peninsula. This study comprehended the characteristics of Jeju Island coastal areas by analyzing severe weather elements like a typhoon, and particularly reviewed design water levels by storm surge in Seogwipo Harbor. The design water level was calculated on the...

  6. Trends in Water Level and Flooding in Dhaka, Bangladesh and Their Impact on Mortality

    OpenAIRE

    Thiele-Eich, Insa; Burkart, Katrin; Simmer, Clemens

    2015-01-01

    Climate change is expected to impact flooding in many highly populated coastal regions, including Dhaka (Bangladesh), which is currently among the fastest growing cities in the world. In the past, high mortality counts have been associated with extreme flood events. We first analyzed daily water levels of the past 100 years in order to detect potential shifts in extremes. A distributed lag non-linear model was then used to examine the connection between water levels and mortality. Results ind...

  7. Changes in Breath Trihalomethane Levels Resulting from Household Water-Use Activities

    Science.gov (United States)

    Gordon, Sydney M.; Brinkman, Marielle C.; Ashley, David L.; Blount, Benjamin C.; Lyu, Christopher; Masters, John; Singer, Philip C.

    2006-01-01

    Common household water-use activities such as showering, bathing, drinking, and washing clothes or dishes are potentially important contributors to individual exposure to trihalomethanes (THMs), the major class of disinfection by-products of water treated with chlorine. Previous studies have focused on showering or bathing activities. In this study, we selected 12 common water-use activities and determined which may lead to the greatest THM exposures and result in the greatest increase in the internal dose. Seven subjects performed the various water-use activities in two residences served by water utilities with relatively high and moderate total THM levels. To maintain a consistent exposure environment, the activities, exposure times, air exchange rates, water flows, water temperatures, and extraneous THM emissions to the indoor air were carefully controlled. Water, indoor air, blood, and exhaled-breath samples were collected during each exposure session for each activity, in accordance with a strict, well-defined protocol. Although showering (for 10 min) and bathing (for 14 min), as well as machine washing of clothes and opening mechanical dishwashers at the end of the cycle, resulted in substantial increases in indoor air chloroform concentrations, only showering and bathing caused significant increases in the breath chloroform levels. In the case of bromodichloromethane (BDCM), only bathing yielded a significantly higher air level in relation to the preexposure concentration. For chloroform from showering, strong correlations were observed for indoor air and exhaled breath, blood and exhaled breath, indoor air and blood, and tap water and blood. Only water and breath, and blood and breath were significantly associated for chloroform from bathing. For BDCM, significant correlations were obtained for blood and air, and blood and water from showering. Neither dibromochloromethane nor bromoform gave measurable breath concentrations for any of the activities investigated because of their much lower tap-water concentrations. Future studies will address the effects that changes in these common water-use activities may have on exposure. PMID:16581538

  8. Paleo-megalake termination in the Quaternary: Paleomagnetic and water-level evidence from south Bohai Sea, China

    Science.gov (United States)

    Yi, Liang; Deng, Chenglong; Xu, Xingyong; Yu, Hongjun; Qiang, Xiaoke; Jiang, Xingyu; Chen, Yanping; Su, Qiao; Chen, Guangquan; Li, Ping; Ge, Junyi; Li, Yan

    2015-04-01

    Asian marginal seas play an important role in moderating material and energy flux linkages between Asia and the Northwest Pacific, and thus have profound climatic and environmental effects. In this study, by combining paleomagnetic study with sediment grain-size analysis on the Lz908 borehole sedimentary sequence from the southern Bohai Sea, new insights into regional geomorphological process since the late early Pleistocene are obtained. The main results are as follows. (1) Paleomagnetic findings suggest that the sequence recorded the Brunhes normal chron and the late Matuyama reverse chron, including the Jaramillo normal subchron. (2) The sedimentary processes in the study area since 1327 ka show a three-stage pattern, with depositional rates of 4.3, 17 and 107 cm/ka during 1327-260 ka (later part of the early and middle Pleistocene), 260-10 ka (late middle and late Pleistocene), and the Holocene, respectively. (3) The sedimentary basin was a part of the Bohai Paleolakes (BHPL) prior to 260 ka, whose water levels were consistently higher than 3 m above the present-day level. After 260 ka, seawater entered the Bohai basin, and relative sea level cyclically fluctuated with global sea-level changes. We therefore infer that the Miaodao Islands, which were the natural barrier of the BHPL blocking seawater entry, had partially subsided before 260 ka, only allowing seawater to enter the basin during a global sea-level maximum. The BHPL terminated around 260 ka, and the "barrier" subsided completely around ~ 130 ka, causing the Bohai basin to become an inner shelf sea.

  9. Influence of tidal fluctuations in the water table and methods applied in the calculation of hydrogeological parameters. The case of Motril-Salobreña coastal aquifer

    Science.gov (United States)

    Sánchez Úbeda, Juan Pedro; Calvache Quesada, María Luisa; Duque Calvache, Carlos; López Chicano, Manuel; Martín Rosales, Wenceslao

    2013-04-01

    The hydraulic properties of coastal aquifer are essential for any estimation of groundwater flow with simple calculations or modelling techniques. Usually the application of slug test or tracers test are the techniques selected for solving the uncertainties. Other methods are based on the information associated to the changes induced by tidal fluctuation in coastal zones. The Tidal Response Method is a simple technique based in two different factors, tidal efficiency factor and time lag of the tidal oscillation regarding to hydraulic head oscillation caused into the aquifer. This method was described for a homogeneous and isotropic confined aquifer; however, it's applicable to unconfined aquifers when the ratio of maximum water table fluctuation and the saturated aquifer thickness is less than 0.02. Moreover, the tidal equations assume that the tidal signal follows a sinusoidal wave, but actually, the tidal wave is a set of simple harmonic components. Due to this, another methods based in the Fourier series have been applied in earlier studies trying to describe the tidal wave. Nevertheless, the Tidal Response Method represents an acceptable and useful technique in the Motril-Salobreña coastal aquifer. From recently hydraulic head data sets at discharge zone of the Motril-Salobreña aquifer have been calculated transmissivity values using different methods based in the tidal fluctuations and its effects on the hydraulic head. The effects of the tidal oscillation are detected in two boreholes of 132 m and 38 m depth located 300 m to the coastline. The main difficulties for the application of the method were the consideration of a confined aquifer and the variation of the effect at different depths (that is not included into the tidal equations), but these troubles were solved. In one hand, the assumption that the storage coefficient (S) in this unconfined aquifer is close to confined aquifers values due to the hydrogeological conditions at high depth and without saturation changes. In the other hand, we have monitored hydraulic head fluctuations due to tidal oscillations in different shallow boreholes close to the shoreline, and comparing with the deep ones. The calculated values with the tidal efficiency factor in the deep boreholes are about one less order of magnitude regarding to the obtained results with time lag method. Nevertheless, the application of these calculation methods based on tidal response in unconfined aquifers provides knowledge about the characteristics of the discharge zone and groundwater flow patterns, and it may be an easy and profitable alternative to traditional pumping tests.

  10. Contested water rights in post-apartheid South Africa: the struggle for water at catchment level

    Scientific Electronic Library Online (English)

    JS, Kemerink; R, Ahlers; P, van der Zaag.

    2011-10-01

    Full Text Available The National Water Act (1998) of South Africa provides strong tools to redress inequities inherited from the past. However, a decade after the introduction of the Act, access to water is still skewed along racial lines. This paper analyses the various ways in which the Water Act is contested, based [...] on empirical data detailing the interactions between smallholder farmers and commercial farmers in a case-study catchment in KwaZulu-Natal Province. The paper argues that the legacy of the apartheid era still dominates the current political and economical reality and shows how the redistribution of water resources is contested by the elite. The paper identifies several issues that prevent the smallholder farmers from claiming their rights, including the institutional arrangements in former homelands, the 'community approach' of Government and NGOs, the disconnect between land and water reform processes, and historically-entrenched forms of behaviour of the various actors. The paper concludes that the difficulties encountered in the water reform process are illustrative for what is happening in the society at large and raises the question as to what price is being paid to maintain the current status quo in the division of wealth?

  11. Fluctuations in coral health of four common inshore reef corals in response to seasonal and anthropogenic changes in water quality.

    Science.gov (United States)

    Browne, Nicola K; Tay, Jason K L; Low, Jeffrey; Larson, Ole; Todd, Peter A

    2015-04-01

    Environmental drivers of coral condition (maximum quantum yield, symbiont density, chlorophyll a content and coral skeletal growth rates) were assessed in the equatorial inshore coastal waters of Singapore, where the amplitude of seasonal variation is low, but anthropogenic influence is relatively high. Water quality variables (sediments, nutrients, trace metals, temperature, light) explained between 52 and 83% of the variation in coral condition, with sediments and light availability as key drivers of foliose corals (Merulina ampliata, Pachyseris speciosa), and temperature exerting a greater influence on a branching coral (Pocillopora damicornis). Seasonal reductions in water quality led to high chlorophyll a concentrations and maximum quantum yields in corals, but low growth rates. These marginal coral communities are potentially vulnerable to climate change, hence, we propose water quality thresholds for coral growth with the aim of mitigating both local and global environmental impacts. PMID:25682391

  12. Prediction of Flow Rate in a Passive Residual Heat Removal System with Various Water Levels

    International Nuclear Information System (INIS)

    A passive residual heat removal system (PRHRS) is one of passive safety systems that have been adopted in SMART. In the case of an emergency such as an unavailability of the secondary side feedwater supply or a station blackout, the PRHRS passively removes the core decay heat and sensible heat through a two-phase natural circulation, and thus maintains the reactor in a stable condition without any AC power or operator actions. The PRHRS consists of an emergency cool-down tank (ECT), a condensing heat exchanger (HX), a makeup tank (MT), valves, pipes, and monitoring instruments. Its conceptual diagram is given in Fig. 1. If the passive residual heat removal actuation signal is generated, the PRHRS starts running. Subcooled water in the HX flows into the secondary side of the SG due to the difference in the water level. The feedwater is evaporated by residual heat, and exits the SG cassette nozzle header at a two-phase flow or superheated steam condition. Then, as it flows into the HX submerged in the ECT, the steam is condensed into subcooled water by emitting the residual heat into the cool-down water. Thus, continuous coolant circulation occurs in the PRHRS. Such a natural circulation becomes weakened, however, as the water level and density differences between the HX and the secondary side of the SG dwindle due to the decrease of residual heat. In this study, therefore, the effects of water level in the PRHRS on the flow rate are theoretically examined. To obtain the flow rate variation, the natural circulation in PRHRS is modeled with basic hydraulic theory. The effect of the water level of the SG, HX and MT on the natural circulation in the PRHRS has been investigated. The HX flow rate also increases with the decrease in the SG water level. It is noted that a natural circulation in PRHRS mainly occurs through the flow path of the HX because the flow path configuration through the MT gives an inherently high hydraulic resistance. Thus, the total flow rate has a similar value as the HX flow rate. The highest HX water level yields 0.6%, 13.4% and 25.0% augmented total flow rates compared to the design flow rate when the SG water level is high, middle, and low, respectively. However, the low water level in the MT provides an extremely low total flow rate owing to the decline in the water level difference

  13. Low-level tritium concentration measurements by liquid scintillation counting in environmental water samples

    International Nuclear Information System (INIS)

    Despite the relatively low toxicity of tritium, monitoring of tritium activity concentrations in the environment is necessary in order to follow up its circulation in the hydrosphere and biosphere. There are two standard recommendations that specify the method for determining tritium concentration in water by liquid scintillation counting. Basically, the principle is the same with small differences between the two chemical treatments of water samples. In the present work, a low background liquid scintillation detector system Quantulus 1220, is used to determine tritium concentration in different sorts of water: drinking water, precipitation water, surface water and wastewater. All samples were measured according to the two studied standards, but we observed several parameters that were important for an accurate scintillation measurement, namely the pH-value, conductivity, and holding time of sample/scintillator mixture. There appears some interferences in the measurement process that lead to different results for the same water sample prepared by the two methods. Establishing the most appropriate routine procedure for tritium measurement in water sample, was the main goal of our study. The results reported to the 6th IAEA Inter-comparison of Low-level Tritium Measurements in Water (TRIC2000) confirm the settled procedure. Even if the uncertainty of the method is high, and even if tritium levels in the environment continue to decrease, the direct measurement of tritiumecrease, the direct measurement of tritium concentration in water samples can still be a more rapid and cheaper measurement method for environment. (authors)

  14. Assessment of sanitation levels of sources of water in Osun State Capital, Nigeria

    Directory of Open Access Journals (Sweden)

    Felix A. Oginni

    2014-12-01

    Full Text Available A study of the physicochemical and bacteriological analysis including BOD and COD was carried out for sources of water in Oshogbo the Capital of the State of Osun. Seven water sampling areas were selected to cover the low, medium and high population density areas of the State Capital. Water samples were collected from five sources of water, namely, shallow well, borehole, stream, rain and river. Water samples were collected from the well, borehole and stream water sources from Dada Estate and Isale Oshun for low density population, Ayetoro, Ogo-Oluwa and Oke-Ayepe for medium density, and Oke-Bale and Igbona for high density population areas. Three sampling points were undertaken for the rain water source while River Oshun source at Isale-Oshun was the 25th water sampling point. A total of 25 water quality parameters were analyzed for each of the 25 water sources sampled using the facility at the Rural Water And Environmental Sanitation Agency, RUWESA in Osun State Government Secretariat in Abere. Results indicated that 8 of the water quality parameters, pH, Turbidity; Magnesium hardness, Free Chlorine, Nitrite, Bacteriological, BOD and COD were not within Standards Organization of Nigeria (SON permitted water quality standards and are of concern to sanitation of potable water in the State Capital. The level of each parameter differs from source to source as well as from level of population densities. The sources that were adjudged polluted were Ogo-Oluwa and Oke-Ayepe well sources; Ogo-Oluwa, Oke-Bale and Igbona stream sources Oke-Bale Rain source.R and the River source at Isale-Oshun. The polluted sources are all within the medium and high population density areas of the State Capital.

  15. Lithostratigraphy of the Middle Eocene Dammam Formation in Qatar, Arabian Gulf: effects of sea-level fluctuations along a tidal environment

    Science.gov (United States)

    Al-Saad, Hamad

    2005-08-01

    The Middle Eocene Dammam Formation dominates the surface exposure of Qatar. It consists of shales followed by limestone and is topped by dolomitic limestone. It is subdivided, from oldest to youngest, into the Midra Shale, Dukhan, Umm Bab and Abaruq members. Three patterns of facies dominate the formation. Shale-marl facies in the lower part, mudstone/wackestone/packstone facies in the middle part and argillaceous dolomitic wackestone/packstone facies in the upper part. The main fauna of the Dammam Formation include Nummulites, Alveolines, Linderines, shark teeth, molluscs and echinoderms. The Nummulites species are common, particularly within the middle members (Dukhan and Umm Bab members). Coarsening-upward parasequences reflect the cyclicity of the Eocene Dammam Formation in Qatar. At least three short-lived transgressive/regressive cyclothems can be recognized in sediments of the formation. These small-scale cycles resulted from fluctuations in sea level. A local hiatus is believed to separate these cycles in northeastern Qatar. A warm shallow marine environment was predominant as indicated by extensive dolomitization and the presence of Alveolines, Linderines and Nummulites with globular tests.

  16. Linking levels of societal and ecosystems metabolism of water in a Mediterranean watershed

    Science.gov (United States)

    Cabello, V.

    2014-12-01

    Water resources degradation is a complex environmental problem that involves multiple dimensions and scales of analysis. The Socio-Ecological Systems Water Metabolism has been proposed as a general holistic framework to deal with integrated analysis of water use sustainability (Madrid and Giampietro 2014). The innovation of the approach is that it sets the research focus beyond the classical supply-demand modeling to societal integrity and ecosystems integrity. To do so, it integrates quantitative grammars of water use (relating water exchange to societal and ecosystems organization) and qualitative methods (discourse analysis). This work presents the first case study focused at a river basin extent: the Upper Andarax, in South-East Spain. Water metabolism is indicated at multiple levels for ecosystems and society. To deal with the interfaces among them, relational indicators of water exploitation, water use and impact over ecosystems are used alongside policies and narratives analysis.While being a rather not intensively exploited river basin (year Water Exploitation Index~0.3 blue water,~0.15 green water), impacts over water bodies are yet important (periodic aquifer overdraft, biological degradation of the river) especially during dry season. Perceived mayor problems of water sustainability are generated by the not integration of different policies at European, national and regional scales: while the water authority establishes a compulsory reduction over water withdrawal to attend environmental flows, agricultural markets force to raise productivity increasing water demands. Adaptation strategies are divided among irrigation efficiency improvement and a reorientation of the economy towards touristic activities. Both of them entail specific trade-offs to be deemed. Aquifer-river interactions and climate change impacts are yet mayor research challenges.

  17. Isotope studies of water dynamics. Implications of the rise of the Caspian Sea level

    International Nuclear Information System (INIS)

    After more than 40 years of continuous decline, since 1978 the Caspian Sea level has been rising and at the end of 1994 it was nearly 2.5 m above the 1978 level. The nature and the mechanism of perpetual sea level variations are unknown. But in this particular case it was observed that the sea level is accompanied by an increase of river runoff from the catchment area and a decrease of evaporation from the sea surface. In order to understand the implications of the sea level rise isotope studies of water dynamics were undertaken by periodical sampling of sea, river and precipitation water. By comparison of oxygen isotopes and salinity distribution it was found that the pattern of the river and sea water mixing is changing. The residence time of water masses of the North Caspian Sea and the main water balance characteristics were determined using oxygen isotope salinity analysis. The problem of vertical mixing processes of cold bottom and warm surface water in the middle and the southern depression was studied using tritium data from sampling cruises in 1983, 1991 and 1994. Owing to an increase of the river runoff the cold bottom water rise was intensified. Consequently the surface layer temperature dropped and evaporation decreased. This feedback effect of water dynamics on sea level variation was derived from the study. Quasi-periodic hydrotroilite layers in the sea bottom core sediments were discovered. Preliminary isotope and chemical analyses show that the hydrotrnd chemical analyses show that the hydrotroilite (FeS·nH2O) is a promising indicator of sea level variation in the past. (author). 5 refs, 6 figs, 2 tabs

  18. TIME SERIES METHODS FOR WATER LEVEL FORECASTING OF DUNGUN RIVER IN TERENGGANU MALAYSIA

    Directory of Open Access Journals (Sweden)

    SITI HAJAR ARBAIN

    2012-04-01

    Full Text Available Due to climate change and global warming, the possibility of floods may increase to occur in Malaysia. Water level forecasting are important for the water catchment management in particular for flood warning systems. The aim of this study is to predict water level with input variables monthly rainfall and rate of evaporation takenfrom the same catchment at Dungun River, Terengganu-Malaysia, using ARIMA and Artificial Neural Network (ANN. The process of pre-processing data has been made to the original rainfall data since they contain imperfect characteristics data. Our experiments show that the ANN with cleansing rainfall data gives better performance than ARIMA and ANN without cleansing data.

  19. Permeability of covers over low-level radioactive-waste burial trenches, West Valley, Cattaraugus County, New York. Water resources investigations (final) 1977-78

    International Nuclear Information System (INIS)

    Gas pressure in the unsaturated parts of radioactive waste burial trenches responds to fluctuations in atmospheric pressure. Measurements of atmospheric pressure and the differential pressure between the trench gas and the atmosphere on several dates in 1977-78 were used to calculate hydraulic conductivity of the reworked silty-clay till that covers the trenches. Generally the hydraulic conductivity of covers over trenches that had a history of rapidly rising water levels are higher, at least seasonally, than covers over trenches in which the water level remained low. This supports the hypothesis that recharge occurs through the cover, presumably through fractures caused by desiccation and (or) subsidence. Hydraulic conductivities of the cover as calculated from gas- and air-pressure measurements at several trenches were 100 to 1,000 times greater than those calculated from the increase in water levels in the trenches. This difference suggests that the values obtained from the air- and gas-pressure measurements need to be adjusted and at present are not directly usable in ground-water flux calculations. The difference in magnitude of values may be caused by rapidly decreasing hydraulic conductivity during periods of recharge or by the clogging of fractures with sediment washed in by runoff

  20. Fluctuation phenomena

    International Nuclear Information System (INIS)

    Fluctuation phenomena are the ''tip of the iceberg'' revealing the existence, behind even the most quiescent appearing macroscopic states, of an underlying world of agitated, ever-changing microscopic processes. While the presence of these fluctuations can be ignored in some cases, e.g. if one is satisfied with purely thermostatic description of systems in equilibrium, they are central to the understanding of other phenomena, e.g. the nucleation of a new phase following the quenching of a system into the co-existence region. This volume contains a collection of review articles, written by experts in the field, on the subject of fluctuation phenomena. Some of the articles are of a very general nature discussing the modern mathematical formulation of the problems involved, while other articles deal with specific topics such as kinetics of phase transitions and conductivity in solids. The juxtaposition of the variety of physical situations in which fluctuation phenomena play an important role is novel and should give the reader an insight into this subject

  1. Elevación máxima del agua en la laguna Mar Chiquita, Córdoba, Argentina / Maximum Water Level in Mar Chiquita, Lagoon, Cordoba, Argentina

    Scientific Electronic Library Online (English)

    Mariana, Pagot; Gerardo, Hillman; Cecilia, Pozzi-Piacenza; Paolo, Gyssels; Antoine, Patalano; Andrés, Rodriguez.

    2014-08-01

    Full Text Available La laguna Mar Chiquita es el mayor cuerpo de agua endorreico de la República Argentina y está ubicada al noreste de la provincia de Córdoba. El nivel de agua máximo es objeto de este trabajo y se definió con base en el efecto combinado del máximo nivel de agua histórico medido sobre la costa sur y d [...] e la máxima sobre-elevación por tormenta estimado para recurrencias de 25, 50 y 100 años. El análisis de las series de niveles de agua permitió definir el valor máximo histórico del nivel medido en la laguna. Este valor se registró en el año 2003 con una cota de 71.9 m sobre nivel del mar (snm). La máxima sobre-elevación por tormenta se definió por la acción conjunta del viento y del oleaje generado por el mismo. Para estas estimaciones se utilizaron programas específicos y formulaciones empíricas. Para propagar el oleaje sobre el perfil de playa, se reconstruyó la batimetría de la laguna, basada en técnicas de teledetección. A tal efecto se utilizaron datos de elevación del terreno, tomando relevamientos espaciales con radar y mapas temáticos derivados de imágenes satelitales ópticas, productos LandSat, basados en el proceso de extracción digital de los contornos de agua. Los resultados indicaron que la cota máxima de inundación de la laguna Mar Chiquita para la costa sur del sistema podría llegar a los 73.5 msnm para una recurrencia de 100 años. Este análisis es importante realizarlo en sistemas que presentan grandes fluctuaciones del nivel de agua, como el aquí presentado. Abstract in english Mar Chiquita lagoon is the largest endorheic body of water in Argentina. It is located in the northeast portion of the province of Cordoba. The maximum water level is the topic of this work, which is defined using the combined effect of the historical maximum water level measured on the coast and th [...] e maximum storm elevation (considering both wind and waves) estimated for recurrences of 25, 50 and 100 years. The analysis of the series of water levels made it possible to determine the historical maximum level measured in the lagoon. This value was recorded in 2003 as a height of 71.9 meters above sea level (masl). The maximum storm level is defined by both the action of the wind and waves generated by the storm. Specific software and empirical formulas were used to obtain these estimates. To propagate the waves on the beach profile, the bathymetry of the lagoon was rebuilt using remote sensing techniques. To this end, terrain elevation data were used from space surveys derived from radar and from thematic maps based on Landsat images with the digital extraction of water contours. The results indicate that the maximum flood that could occur in Laguna Mar Chiquita, on the southern coast of the system, is 73.5 masl with a recurrence of 100 years. It is important to conduct this analysis for systems with large fluctuations in water levels, such as the one presented here.

  2. Flutuação populacional e intensidade de infestação da broca-dos-frutos em cupuaçu Population fluctuation and infestation levels of the cupuaçu fruit borer

    Directory of Open Access Journals (Sweden)

    Marcílio José Thomazini

    2002-09-01

    Full Text Available Dentre as pragas do cupuaçueiro Theobroma grandiflorum (Wild. ex Spreng. Schum., a broca-dos-frutos, Conotrachelus humeropictus Fiedler (Coleoptera: Curculionidae, é a mais importante, devido aos danos causados e por estar disseminada em alguns Estados da região Norte do Brasil. Os objetivos deste trabalho foram avaliar a flutuação populacional de adultos de C. humeropictus, determinar a intensidade de infestação e caracterizar o ataque de larvas desta praga em frutos de cupuaçueiros, em sistemas agroflorestais no Estado de Rondônia. Para obter a flutuação populacional de adultos da broca, foram amostradas semanalmente, durante o período de março/98 a julho/00, 20 plantas de cupuaçu, pelo método do sacolejo, em duas áreas de agrossilvicultores. A avaliação da população de larvas foi realizada durante duas safras, onde foram coletados e abertos frutos atacados pela broca. A determinação da infestação da praga foi obtida através da porcentagem de frutos broqueados. Adultos de C. humeropictus ocorrem durante todo ano nas plantas de cupuaçu, na área estudada, mas predominam na floração, início da frutificação e durante o período de safra. Tanto os frutos verdes como os maduros são atacados, sendo que larvas de idades diferentes podem ocorrem em um mesmo fruto. Perdas superiores a 50% na produção de frutos, devido ao ataque da broca, ressaltam a importância desta praga na região.The most important pest of the cupuaçu crop is the fruit borer, Conotrachelus humeropictus Fiedler (Coleoptera: Curculionidae, wich severely damages fruits and is disseminated all over North Brazil. The objectives of this study were evaluating the population fluctuations of C. humeropictus adults, infestation levels and to characterize the pest larval attack in cupuaçu fruits of agroforestry systems of the Rondonia State, Brazil. Population fluctuations from C. humeropictus adults were evaluated weekly from March/98 to July/00 in twenty cupuaçu plants, by shaking the tree branches, of two producer areas. During two harvest periods, fruits attacked by the borer were collected and examined for evaluation of larvae population. Pest infestation was determined by the percentage of damaged fruits. C. humeropictus adults occur year around on cupuaçu plants, but predominate at the stages of flowering, fruit formation and during the harvest period. It was observed that mature and non-mature fruits are attacked by the pest; larvae of different ages can occur in a same fruit; the insect may cause losses greater than 50% of fruit yield.

  3. Flutuação populacional e intensidade de infestação da broca-dos-frutos em cupuaçu / Population fluctuation and infestation levels of the cupuaçu fruit borer

    Scientific Electronic Library Online (English)

    Marcílio José, Thomazini.

    2002-09-01

    Full Text Available Dentre as pragas do cupuaçueiro Theobroma grandiflorum (Wild. ex Spreng.) Schum., a broca-dos-frutos, Conotrachelus humeropictus Fiedler (Coleoptera: Curculionidae), é a mais importante, devido aos danos causados e por estar disseminada em alguns Estados da região Norte do Brasil. Os objetivos deste [...] trabalho foram avaliar a flutuação populacional de adultos de C. humeropictus, determinar a intensidade de infestação e caracterizar o ataque de larvas desta praga em frutos de cupuaçueiros, em sistemas agroflorestais no Estado de Rondônia. Para obter a flutuação populacional de adultos da broca, foram amostradas semanalmente, durante o período de março/98 a julho/00, 20 plantas de cupuaçu, pelo método do sacolejo, em duas áreas de agrossilvicultores. A avaliação da população de larvas foi realizada durante duas safras, onde foram coletados e abertos frutos atacados pela broca. A determinação da infestação da praga foi obtida através da porcentagem de frutos broqueados. Adultos de C. humeropictus ocorrem durante todo ano nas plantas de cupuaçu, na área estudada, mas predominam na floração, início da frutificação e durante o período de safra. Tanto os frutos verdes como os maduros são atacados, sendo que larvas de idades diferentes podem ocorrem em um mesmo fruto. Perdas superiores a 50% na produção de frutos, devido ao ataque da broca, ressaltam a importância desta praga na região. Abstract in english The most important pest of the cupuaçu crop is the fruit borer, Conotrachelus humeropictus Fiedler (Coleoptera: Curculionidae), wich severely damages fruits and is disseminated all over North Brazil. The objectives of this study were evaluating the population fluctuations of C. humeropictus adults, [...] infestation levels and to characterize the pest larval attack in cupuaçu fruits of agroforestry systems of the Rondonia State, Brazil. Population fluctuations from C. humeropictus adults were evaluated weekly from March/98 to July/00 in twenty cupuaçu plants, by shaking the tree branches, of two producer areas. During two harvest periods, fruits attacked by the borer were collected and examined for evaluation of larvae population. Pest infestation was determined by the percentage of damaged fruits. C. humeropictus adults occur year around on cupuaçu plants, but predominate at the stages of flowering, fruit formation and during the harvest period. It was observed that mature and non-mature fruits are attacked by the pest; larvae of different ages can occur in a same fruit; the insect may cause losses greater than 50% of fruit yield.

  4. Basic concepts for the linear model of ground water level recession

    Science.gov (United States)

    Rutledge, A.T.

    2006-01-01

    Basic concepts are illustrated for the display of ground water level recession as a linear plot on a semilog graph, as first described by Rorabaugh. This exponential decay function can be achieved if there is a definable outflow boundary such as a lake or river and if water levels are expressed relative to the altitude of the boundary. The model can be used to estimate aquifer hydraulic diffusivity. Concepts are illustrated using three finite-difference simulations. One represents the ideal case as described by Rorabaugh, in which the altitude of the outflow boundary is uniform along its length. Another simulation includes a sloping boundary with simple geometry and demonstrates that the model can be used accurately. Based on this simulation, it appears that the ground water level must be expressed relative to the closest point on the outflow boundary. The third simulation includes a sloping boundary and complex boundary shape, and demonstrates departures from the linear model of recession and errors in the estimate of hydraulic diffusivity. Another cause of nonlinearity is the instability of the ground water head profile soon after a recharge event. The nature of these early-time departures will vary depending on the location of the water level observation site relative to the outflow boundary and the hydrologic divide of the ground water flow system. ?? 2006 National Ground Water Association.

  5. Laboratory and field tests of the Sutron RLR-0003-1 water level sensor

    Science.gov (United States)

    Fulford, Janice M.; Bryars, R. Scott

    2015-01-01

    Three Sutron RLR-0003-1 water level sensors were tested in laboratory conditions to evaluate the accuracy of the sensor over the manufacturer’s specified operating temperature and distance-to-water ranges. The sensor was also tested for compliance to SDI-12 communication protocol and in field conditions at a U.S. Geological Survey (USGS) streamgaging site. Laboratory results were compared to the manufacturer’s accuracy specification for water level and to the USGS Office of Surface Water (OSW) policy requirement that water level sensors have a measurement uncertainty of no more than 0.01 foot or 0.20 percent of the indicated reading. Except for one sensor, the differences for the temperature testing were within 0.05 foot and the average measurements for the sensors were within the manufacturer’s accuracy specification. Two of the three sensors were within the manufacturer’s specified accuracy and met the USGS accuracy requirements for the laboratory distance to water testing. Three units passed a basic SDI-12 communication compliance test. Water level measurements made by the Sutron RLR-0003-1 during field testing agreed well with those made by the bubbler system and a Design Analysis Associates (DAA) H3613 radar, and they met the USGS accuracy requirements when compared to the wire-weight gage readings.

  6. The effect of applying different water levels and irrigation frequencies in propagating rosemary (Rosmarinus officinalis L.

    Directory of Open Access Journals (Sweden)

    Javier Giovanni Álvarez Herrera

    2010-05-01

    Full Text Available Rosemary seedlings are obtained by vegetative propagation because the seeds present low viability. Despite being an expanding crop, there is little information on water consumption during the propagation stage. Water levels and irrigation frequencies were therefore applied using a completely randomised design having a 4 x 2 factorial arrangement. The first factor concerned irrigation frequency (4 and 8 days and the second concerned water level (0.6, 0.8, 1.0 and 1.2 evaporation inside the greenhouse. A 1.0 coefficient combined with 4-day irrigation frequency presented the best results regarding height (39.3 cm, fresh weight, dry weight and branch length (146 cm. Water level affected the fresh and dry weight of leaves regardless of frequency. Relative water content in leaves did not present differences due to environmental conditions minimising treatment effect. Rooting percent- tage showed no significant differences regarding irrigation frequency or water level. Irrigation frequency did not affect rosemary growing pattern because sphagnum retains high moisture content. The best branch number (34 was obtained with 1.0 coefficient and 4-day frequency, this being important from the production point of view because this is the material which is sold. Water management changes photoassimilate distribution in rosemary plants.

  7. Estimating severity of seismically induced landslides and lateral spreads using threshold water levels

    Science.gov (United States)

    Chung, Jae-won; Rogers, J. David; Watkins, Conor M.

    2014-01-01

    The potential for an earthquake-induced landslide increases when the shear strength of a slope decreases and the hydrostatic pressure increases from the dynamic stresses induced by seismic shaking and/or heavy rainfalls. This paper presents an assessment of seismically induced slope failure in the St. Louis, MO, USA, area; it emphasizes water elevations as the controlling factor, realizing that such levels vary over space and time. We estimated the threshold water table depths to initiate seismically induced landslides in the uplands and liquefaction-induced lateral spreads in the alluvial floodplains under an M7.5 earthquake with a peak ground acceleration of 0.20 to 0.40 g. These threshold water table depths were computed as a function of ground steepness using the Newmark model for rigid block landslides and an empirical regression for lateral spreads. The seismic microzonation was prepared by comparing the map of threshold water table depths and maps of average water levels. The resultant hazard maps suggest that the river bluffs are prone to seismically induced landslides only when the water reaches its highest recorded levels, while much of the floodplains are prone to lateral spreads. Lateral spreads occur more extensively when the water exceeds its normal level.

  8. NMR study of seed hydration with deuterated water: Dependence of proton signals on hydration level

    International Nuclear Information System (INIS)

    Proton NMR signals in seeds are shown to depend on hydration level. In fact at low water amount, as it occurs in many native seeds, protons can have a restricted mobility and are not detectable. A NMR method for measuring the dependence of proton signals on hydration is reported. The method also allows the separation of the contributions of water and non-water protons in a low-resolution NMR experiment. It is based on successive hydrations (with deuterated water) - desiccation steps and on the analysis of the transverse magnetization decay curves

  9. Trench water chemistry at commercially operated low-level radioactive waste disposal sites

    International Nuclear Information System (INIS)

    Water samples from the disposal trenches of two low-level radioactive-waste-disposal sites were analyzed for their inorganic, organic, and radionuclide contents. Since oxidation of the trench waters can occur during their movement along the groundwater flow path, experiments were performed to measure the chemical and physical changes that occur in these waters upon oxidation. Low concentrations of chelating agents, shown to exist in trench waters, may be responsible for keeping radionuclides, particularly 60Co, in solution. 4 figures, 5 tables

  10. Response of Drip Irrigated Sorghum Varieties Growing in Dune Sand to Salinity Levels in Irrigation Water

    OpenAIRE

    B.A. Ould Ahmed; Yamamoto, T.; Inoue, M.

    2007-01-01

    Saline-water drip irrigated sorghum varietal response to limited available soil water in dune sand was assessed using salinity response function. In a randomized complete block design three sorghum varieties (Local sorghum, BK 16 and EC 90) were grown with drip irrigated saline-water, at four salinity levels (5.47, 7.32, 9.38 and 12.50 dS m-1) and with quality water of 0.11 dS m-1 serving as the control. Four salinity response models were used to assess their ability to discriminate sa...

  11. Assessment of radon-222 levels in drinking water sources of Tula region

    International Nuclear Information System (INIS)

    Field technique of sampling and radon transfer to measuring chamber of radiometer for radon level determination in natural waters is described. The circuit of radiometric device, enabling to measure radon content in water up to its concentrations of 1-2 Bq/l, is given. Results of examination of 60 drinking water sources in four areas of Tula region, conducted with the use of mentioned technique, are presented. It is shown that radon concentration in used water sourceschanges by more, than 2 orders - from 1 to 250 Bq/l

  12. Kalman filter approach for estimating water level time series over inland water using multi-mission satellite altimetry

    Science.gov (United States)

    Schwatke, C.; Dettmering, D.; Bosch, W.; Seitz, F.

    2015-05-01

    Satellite altimetry has been designed for sea level monitoring over open ocean areas. However, since some years, this technology is also used for observing inland water levels of lakes and rivers. In this paper, a new approach for the estimation of inland water level time series is described. It is used for the computation of time series available through the web service "Database for Hydrological Time Series over Inland Water" (DAHITI). The method is based on a Kalman filter approach incorporating multi-mission altimeter observations and their uncertainties. As input data, cross-calibrated altimeter data from Envisat, ERS-2, Jason-1, Jason-2, Topex/Poseidon, and SARAL/AltiKa are used. The paper presents water level time series for a variety of lakes and rivers in North and South America featuring different characteristics such as shape, lake extent, river width, and data coverage. A comprehensive validation is performed by comparison with in-situ gauge data and results from external inland altimeter databases. The new approach yields RMS differences with respect to in-situ data between 4 and 38 cm for lakes and 12 and 139 cm for rivers, respectively. For most study cases, more accurate height information than from available other altimeter data bases can be achieved.

  13. Stratification in the reactor water level instrumentation system caused by backfill modification in a BWR plant

    International Nuclear Information System (INIS)

    Due to the radiolysis inside Boiling Water Reactors, gases will be generated and can submerge into the water of the reference leg of the instrumentation. This will induce erroneous indication of RPV water level. To correct this phenomenon, a continuous backfill system is designed for most of the BWR plants. However, this backfill modification requires an injection of cold water into the instrumentation line. This condition will cause thermal stratification of the instrument system and create additional loading on piping, equipment and reactor nozzle. Analytical procedure is developed to convert a three-dimensional thermal hydraulic and conjugate heat transfer solution into stratification moments and local stresses on the condensing chamber and to determine the variable stratification moments and local stresses of the pipe. This procedure enables the qualification of the reactor water level instrumentation system by a standard pipe stress analysis computer code

  14. Wheat Productivity, Land and Water Use Efficiency by Traditional and Laser Land-leveling Techniques

    Directory of Open Access Journals (Sweden)

    Muhammad Asif

    2003-01-01

    Full Text Available Present study was conducted to determine the impact of laser land leveling versus traditional land leveling on wheat productivity, land and water-use efficiency during Rabi 2000-2001. The result indicated that Laser land leveling gave significantly higher grain yields (5.56 t ha-1 than the unleveled land (3.99 t ha-1 but was at par with traditionally leveled one. However, no significant differences among the treatments were recorded for 1000-grain weight and grains ear-1. The total irrigation duration and applied water depth was reduced by 47 and 15% as compared to unleveled and traditional leveled fields, respectively. The laser-leveled fields exhibited the highest water use efficiency (WUE, which was 98.7 and 29.36% higher than the unleveled and traditionally leveled field, respectively. It was concluded that the use of Laser Land leveling surely increases grain yield and save irrigation water as compared to traditional method of sowing.

  15. HEADCO: a program for converting observed water levels and pressure measurements to formation pressure and standard hydraulic head

    International Nuclear Information System (INIS)

    Static water-level and fluid pressure measurements are commonly converted in hydrologic studies to formation pressure and hydraulic head, which are used to determine groundwater flow characteristics of aquifer systems. While the direct use of field measurements is usually adequate for determining formation pressure and hydraulic head for shallow flow systems (i.e., <1000 ft), corrections and conversion parameters must be used to properly account for fluid-column density effects, which commonly occur with deep systems. This report presents a program, HEADCO, for converting static water-level and pressure measurements to formation pressure and standard hydraulic head. The HEADCO program corrects field measurements for the effects of fluid-density variation and selected external stresses. Factors that affect density of the fluid column, in which field measurements are made, include temperature, pressure, salinity, suspended solids, and multiphase conditions. External stresses examined in HEADCO include barometric and earth tide fluctuations, and gravitational acceleration variation. A program description and procedures for converting field measurements obtained using field test arrangements commonly employed in the Basalt Waste Isolation Project field program are provided in this report. The report includes user instructions and an illustrative test example. Results of a field example comparison are also provided. This comparison examines observed and HEADCO-calculated p examines observed and HEADCO-calculated pressures for 30 pressure probes recently calibrated in a laboratory and tested under field conditions at borehole DC-8. The test case and field example comparisons indicate that HEADCO provides accurate estimates of formation pressure and standard hydraulic head that are well within the accuracy range of downhole pressure-measuring instrumentation. 44 refs., 14 figs., 8 tabs

  16. Radar Based Flow and Water Level Forecasting in Sewer Systems : a danisk case study

    OpenAIRE

    Thorndahl, Søren Liedtke; Rasmussen, Michael R.; Grum, M.; Neve, S. L.

    2009-01-01

    This paper describes the first radar based forecast of flow and/or water level in sewer systems in Denmark. The rainfall is successfully forecasted with a lead time of 1-2 hours, and flow/levels are forecasted an additional ½-1½ hours using models describing the behaviour of the sewer system. Both radar data and flow/water level model are continuously updated using online rain gauges and online in-sewer measurements, in order to make the best possible predictions. The project show very prom...

  17. Holocene hydrological changes in south-western Mediterranean as recorded by lake-level fluctuations at Lago Preola, a coastal lake in southern Sicily, Italy

    Science.gov (United States)

    Magny, Michel; Vannière, Boris; Calo, Camilla; Millet, Laurent; Leroux, Aurélie; Peyron, Odile; Zanchetta, Gianni; La Mantia, Tommaso; Tinner, Willy

    2011-09-01

    This paper presents a high-resolution lake-level record for the Holocene at Lago Preola (Sicily, southern Italy) based on a specific sedimentological approach, with a chronology derived from AMS radiocarbon dates. It gives evidence of three major successive palaeohydrological periods, with (1) a pronounced dryness during the early Holocene until ca 10300 cal BP, (2) a highstand from ca 10300 to 4500 cal BP, and (3) a marked lowstand from 4500 cal BP to present. Large amplitude lake-level fluctuations characterise two transition phases at ca 10300-9000 and 6400-4500 cal BP. Period 2 was interrupted between 8300 and 7000 cal BP by a dry phase that was punctuated to ca 7300 cal BP by the deposition of a tephra from neighbouring Pantelleria Island. Comparisons of the Preola record with other palaeohydrological records along north-south and west-east transects in the Mediterranean show contrasting patterns of hydrological changes: north (south) of around 40°N latitude, the records highlight a mid-Holocene period characterised by lake-level minima (maxima). Humid mid-Holocene conditions over the Mediterranean south of 40°N were probably linked to a strong weakening of the Hadley cell circulation and of monsoon winds. We suggest that the maximum of humidity in the Mediterranean during the mid-Holocene was characterised by humid winters to the north of 40°N and humid summers to the south. On a multi-centennial scale, the high-resolution palaeohydrological reconstructions in the central Mediterranean area reveal a strong climate reversal around 4500-4000 cal BP, with contrasting changes in the hydrological cycle. In addition to seasonal and inter-hemispherical changes related to orbital forcing, this major oscillation might be related to non-linear responses of the climatic system to the gradual decrease in summer insolation at northern latitudes. Another major climate oscillation around 7500-7000 cal BP may have resulted from the combined effects of (1) a strong rate of change in insolation, and (2) variations in solar activity. Finally, comparisons of the Preola lake-level record with Sicilian pollen records suggest a strong influence of moisture availability on vegetation development in Sicily. Very dry early Holocene conditions probably prevented the expansion of coastal evergreen forests, while decreasing moisture availability since the onset of the late Holocene may have exacerbated effects of intensive land-use.

  18. Paleohydrology of the southern Great Basin, with special reference to water table fluctuations beneath the Nevada Test Site during the Late Pleistocene

    International Nuclear Information System (INIS)

    The magnitude of water table rise during Pleistocene pluvial climates, and of the resultant shortening of ground-water flow path and reduction in unsaturated zone thickness, is investigated. The distribution of calcitic veins in alluvium and lakebeds, and of tufa deposits, between the Ash Meadows spring discharge area and the Nevada Test Site suggests that discharge from the regional Paleozoic carbonate aquifer during the Late Pleistocene occurred at distances as much as 14 kilometers northeast of Ash Meadows and at altitudes up to 50 meters higher than at present. Use of the underflow equation (relating discharge to transmissivity, aquifer width, and hydraulic gradient), and various assumptions regarding pluvial recharge, transmissivity, and altitude of ground-water base level, suggest possible rises in potentiometric level in the carbonate aquifer of 6 to 90 meters beneath central Frenchman Flat, 58 kilometers northeast of Ash Meadows. During Wisconsin time the rise probably did not exceed 30 meters. Water-level rises beneath Frenchman Flat during future pluvials are unlikely to exceed 30 meters, and future levels might even be 10 meters lower than the modern one, 210 meters beneath the center of the valley. Neither the cited rise in potentiometric level in the regional carbonate aquifer, nor the shortened flow path during the Late Pleistocene precludes utilization of the NTS as a repository for high-level or transuranic-element radioactive wastes provided other reqment radioactive wastes provided other requisite conditions are met at this site. Deep water tables, attendant thick (up to several hundred meter) unsaturated zones, and ground-water flow paths tens of kilometers in length characterized the region during Wisconsin time and possibly throughout the Pleistocene, and are likely to so characterize it during future pluvial climates

  19. Early Water Stress Detection Using Leaf-Level Measurements of Chlorophyll Fluorescence and Temperature Data

    Directory of Open Access Journals (Sweden)

    Zhuoya Ni

    2015-03-01

    Full Text Available The purpose of this paper was to investigate the early water stress in maize using leaf-level measurements of chlorophyll fluorescence and temperature. In this study, a series of diurnal measurements, such as leaf chlorophyll fluorescence (Fs, leaf spectrum, temperature and photosynthetically active radiation (PAR, were conducted for maize during gradient watering and filled watering experiments. Fraunhofer Line Discriminator methods (FLD and 3FLD were used to obtain fluorescence from leaves spectrum. This simulated work using the SCOPE model demonstrated the variations in fluorescence and temperature in stress levels expressed by different stress factors. In the field measurement, the gradient experiment revealed that chlorophyll fluorescence decreased for plants with water stress relative to well-water plants and Tleaf-Tair increased; the filled watering experiment stated that chlorophyll fluorescence of maize under water stress were similar to those of maize under well-watering condition. In addition, the relationships between the Fs, retrieved fluorescence, Tleaf-Tair and water content were analyzed. The Fs determination resulted to the best coefficients of determination for the normalized retrieved fluorescence FLD/PAR (R2 = 0.54, Tleaf-Tair (R2 = 0.48 and water content (R2 = 0.71. The normalized retrieved fluorescence yielded a good coefficient of determination for Tleaf-Tair (R2 = 0.48. This study demonstrated that chlorophyll fluorescence could reflect variations in the physiological states of plants during early water stress, and leaf temperature confirmed the chlorophyll fluorescence analysis results and improved the accuracy of the water stress detection.

  20. DENTAL CARIES AND FLOUROSIS IN DIFFERENT LEVELS OF DRINKING WATER FLOURIDE

    OpenAIRE

    Khademi, H.; Taleb, M.

    2000-01-01

    Introduction. In some area of our country for example: Bushehre, some parts of Hormozgan, Yazd, Azarbayjan provinces, the levels of fIouride in drinking water is over optimom level. So because of this reason the incidence of flourosis in these areas is high. Determination of dental flourosis in four areas of Najafabad, Filor, Joozdan and Rahmatabad with different levels of flourosis with DMFT index is the aim of this study. Methods. This study is a cross sectional study. Samples have bee...

  1. Wood–water interactions : Linking molecular level mechanisms with macroscopic performance

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2011-01-01

    Predicting the performance of wood for decades ahead is important when using the material for structural purposes. The performance is closely related to the hierarchical material structure of wood and the dependent interaction with water in the structure. Accurately predicting wood performance therefore requires an understanding of material structure from molecular to macroscopic level as well as of the impact of water molecules. The objective of this work is to investigate the performance of wood in terms of mechanical response of the material and effect of water. To understand the latter, one must first know in which parts of the wood structure, water is located. If parts of the water in wood are held in capillaries in the wood structure, these water molecules interact with the material differently than those held within wood cell walls. In this study, the occurrence of capillary water in wood is investigated at high levels of relative humidity (RH), where capillary water might be present. Three different techniques are employed in overlapping RH regimes. The three techniques give similar results and show that the amount of capillary water is insignificant up to at least 99.5 % RH. Thus, for wood in equilibrium with surrounding climate in the RH range 0-99.5 %, water is only significantly present within cell walls. A structural model of a wood cell is developed in this study using Finite Element Method for predicting the mechanical performance of wood. The starting point for the model is the physical behaviour on the molecular level since water interferes with wood at this level. The elastic material properties of the wood cell wall are explained by the organisation of wood constituents and their properties. The effect of water as well as temperature is incorporated by considering the amount of hydrogen bonds between wood constituents and the stiffness of these bonds. The mechanical response of wood includes a substantial time-dependent response, which previously has been explained by sliding between wood constituents on the molecular level. In this study, this is incorporated in the model as time-dependent shearing of the material planes of the cell wall. The calculated results of the model is verified against various experimental results from literature as well as from measurements presented in this work. It is shown that the structural model is able to describe a diverse range of mechanical responses of wood cells in both elastic and time-dependent domains. Furthermore, comparison of results from experiments and model suggests that the mechanical response of wood tissue, i.e. the hierarchical level above single wood cells, is a sum of responses from both wood cells and intercellular layer, i.e. the middle lamella.

  2. Louisiana/Everglades wetland water level monitoring using satellite radar altimetry

    Science.gov (United States)

    Lee, H.; Shum, C.; Lu, Z.; Alsdorf, D.; Ibaraki, M.; Braun, A.; Kuo, C.

    2008-05-01

    Coastal estuaries, which connect coastal ocean, wetlands and coastal land region, play important roles in ecological environments. Wetlands typically occur in low-lying areas on the edges of lakes, and rivers, or in coastal areas protected from waves and are found in a variety of climates on every continent except Antarctica. Wetlands not only provide habitat for thousands of aquatic/terrestrial plant and animal species but also control floods by holding water much like a sponge by absorbing and reducing the velocity of storm-water. Human activities have so many negative impacts on wetlands and they became main contributing factors to the wetlands losses. For example, Louisiana's wetlands have lost more than 100 km2 of its area per year (Walker et al., 1987; Bourne, 2000). The loss of Louisiana wetlands as a result of ecological erosion or geological subsidence potentially have had significant impacts in slowing down storm surge from the devastating Hurricane Katrina. The ability to quantitatively measure accurate wetland water level changes in Louisiana has impacts on ecology and natural hazards mitigation including improved storm surge modeling resulting from hurricanes. Interferometric synthetic aperture radar (InSAR) has been proven to be useful to measure centimeter-scale water level changes over Amazon flood plain and Everglades wetland using L-band SAR imagery. This is based on the fact that flooded forests permit double-bounce returns, which allow InSAR coherence to be maintained. Furthermore, ERS-1/2 C-band InSAR data have been used to demonstrate its feasibility to monitor water level changes over Louisiana wetlands. In addition, satellite radar altimetry has been used to measure inland water level variation over large river basins. In this study, we use the decadal (1992-2002) Topex/Poseidon (T/P) measurements from cycle 9 to 364 to detect water</