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Sample records for recharge des nappes

  1. Recharge

    SciTech Connect

    Fayer, Michael J.

    2008-01-17

    This chapter describes briefly the nature and measurement of recharge in support of the CH2M HILL Tank Farm Vadose Zone Project. Appendix C (Recharge) and the Recharge Data Package (Fayer and Keller 2007) provide a more thorough and extensive review of the recharge process and the estimation of recharge rates for the forthcoming RCRA Facility Investigation report for Hanford single-shell tank (SST) Waste Management Areas (WMAs).

  2. Crimean orogene: A nappe interpretation

    SciTech Connect

    Popadyuk, I.V.; Smirnov, S.E. )

    1993-09-01

    On the International Tectonic Map of Europe, the Crimean orogene presents a structure that has no analog in the Alpine orogenic belt. The Crimean mountain system lacks nappe structures of Alpine age. Its geosynclinal folding deformation is restricted to the Tavria flysch formation, previously dated as Triassic-Liassic. Therefore, the Crimean orogene was considered as the Kimmerian tectonotype. In our model, the Crimean orogene is characterized by nappe structures. The Yayla nappe is composed to Upper Jurassic and Neocomian sediments and is located below the Tavrian nappe, which consists of the Tavrian flysch formation. We dated the age of the Tavrian formation as Hauterivian-Aptian on the basis of published ammonite finds in the stratotype section. Nappe displacements are dated roughly as Austrian (albian) by the occurrence of upper-middle Albian sediments below the nappes and the Upper Cretaceous age of their neoautochthonous sedimentary cover. These north-vergent nappes have a horizontal displacement of about 20 km. In the eastern part of the orogene, these nappe structures were overprinted by Laramide-Savic (Paleocene and end Oligocene-early Miocene) deformations, as evident in the Kerch peninsula. The nature of these late deformation is not clear. The hydrocarbon potential of the prenapping autochthonous series has not yet been studied. Exploration for oil and gas in the Crimean sector of the Black Sea must take the suggested model and its implications into account.

  3. Phénomènes karstiques fossiles et actuels au sein des formations métamorphiques silico-alumineuses de la nappe pan-africaine de Yaoundé (Sud-Cameroun)Fossil and present-time karstic phenomena in silico-aluminous metamorphic formations of the Pan-African nappe of Yaoundé (South-Cameroon)

    NASA Astrophysics Data System (ADS)

    Vicat, Jean-Paul; Mvondo, Hubert; Willems, Luc; Pouclet, André

    Numerous karstic features have been recognised in the non-carbonaceous micaschists and gneisses of the Yaoundé Pan-African nappe, south of Cameroon. It is shown that their formation was controlled by the structural features of the rocks. The wells and the pipes in the bedrock outcrops point out a current karstification process, resulting from the plagioclase dissolution by the acid rain waters. Hill wall alveoli and caves, of pre-Miocene age, are exhumed features that were done by dissolution in the aquiferous underground. To cite this article: J.-P. Vicat et al., C. R. Geoscience 334 (2002) 545-550.

  4. NAPP: the Nucleic Acid Phylogenetic Profile Database.

    PubMed

    Ott, Alban; Idali, Anouar; Marchais, Antonin; Gautheret, Daniel

    2012-01-01

    Nucleic acid phylogenetic profiling (NAPP) classifies coding and non-coding sequences in a genome according to their pattern of conservation across other genomes. This procedure efficiently distinguishes clusters of functional non-coding elements in bacteria, particularly small RNAs and cis-regulatory RNAs, from other conserved sequences. In contrast to other non-coding RNA detection pipelines, NAPP does not require the presence of conserved RNA secondary structure and therefore is likely to identify previously undetected RNA genes or elements. Furthermore, as NAPP clusters contain both coding and non-coding sequences with similar occurrence profiles, they can be analyzed under a functional perspective. We recently improved the NAPP pipeline and applied it to a collection of 949 bacterial and 68 archaeal species. The database and web interface available at http://napp.u-psud.fr/ enable detailed analysis of NAPP clusters enriched in non-coding RNAs, graphical display of phylogenetic profiles, visualization of predicted RNAs in their genome context and extraction of predicted RNAs for use with genome browsers or other software.

  5. Estimation of groundwater recharge using the chloride mass-balance method, Pingtung Plain, Taiwan

    NASA Astrophysics Data System (ADS)

    Ting, Cheh-Shyh; Kerh, Tienfuan; Liao, Chiu-Jung

    Due to rapid economic growth in the Pingtung Plain of Taiwan, the use of groundwater resources has changed dramatically. Over-pumping of the groundwater reservoir, which lowers hydraulic heads in the aquifers, is not only affecting the coastal area negatively but has serious consequences for agriculture throughout the plain. In order to determine the safe yield of the aquifer underlying the plain, a reliable estimate of groundwater recharge is desirable. In the present study, for the first time, the chloride mass-balance method is adopted to estimate groundwater recharge in the plain. Four sites in the central part were chosen to facilitate the estimations using the ion-chromatograph and Thiessen polygon-weighting methods. Based on the measured and calculated results, in all sites, including the mountain and river boundaries, recharge to the groundwater is probably 15% of the annual rainfall, excluding recharge from additional irrigation water. This information can improve the accuracy of future groundwater-simulation and management models in the plain. Résumé Du fait de la croissance économique rapide de la plaine de Pingtung à Taiwan, l'utilisation des ressources en eau souterraine s'est considérablement modifié. La surexploitation des aquifères, qui a abaissé le niveau des nappes, n'affecte pas seulement la région côtière, mais a de sérieuses répercutions sur l'agriculture dans toute la plaine. Afin de déterminer les ressources renouvelables de l'aquifère sous la plaine, une estimation précise de la recharge de la nappe est nécessaire. Dans cette étude, le taux de recharge de la nappe a d'abord été estimé au moyen d'un bilan de matière de chlorure. Quatre sites de la partie centrale ont été sélectionnés pour réaliser ces estimations, à l'aide d'un chromatographe ionique et de la méthode des polygones de Thiessen. A partir des résultats mesurés et calculés, à chaque site, et en prenant comme limites les montagnes et les rivi

  6. Nappe emplacement under lateral pressure gradient

    NASA Astrophysics Data System (ADS)

    Podladchikov, Yury; Schmalholz, Stefan

    2014-05-01

    New thin viscous approximation is under development specifically targeted to model spontaneous initiation and tens of kilometers horizontal displacement of tectonic nappes. Nappes are few kilometers thing and tens of kilometers long rock units trusted towards foreland often preserving internal lithological consistency and laying at near horizontal position at the end of the emplacement. Significant shear stresses and deviation of principal stresses from vertical is required to explain this very peculiar strain localization style from mechanical point of view. There is also a need for the explanation of their common appearances in most collisional settings. Both pure shear thin sheet and flexural models kinematically eliminate nappes formation. Spreading viscous sheet models, such as used to model glaciers, are also not applicable as the direction of motion is upward, against gravity. The reason for this discrepancy is the hydrostatic pressure approximation of the gravity-driven spreading models. Actually, the thin sheet approximation is not sensitive to the assumptions made on pressure profile. Lateral non-lithostatic pressure gradient-driven viscous sheet model is appropriate for modeling of nappes. In turn, significant non-lithostatic pressure must be supported by flexural rigidity of overlying and underlying units. Lateral gradients of this non-lithostatic pressure are responsible for the significant shear stress and, therefore, deviation of principal stress from vertical.

  7. Synthese, etude structurale et electrochimique des materiaux d'electrode positive d'oxydes mixtes lithium cobalt nickel oxide (0 /= 1) pour les batteries rechargeables au lithium

    NASA Astrophysics Data System (ADS)

    Grincourt, Yves

    Depuis une dizaine d'annees, on observe un interet grandissant pour les batteries rechargeables au lithium de tension superieure a 4 volts. La commercialisation de ces batteries pour l'electronique grand marche tend de plus en plus a supplanter celle des accumulateurs Ni-Cd et Ni-MH, de tension nominate 1,2 V. Ces batteries au lithium font appel a des materiaux d'electrode positive (cathode a la decharge) du type oxydes mixtes de metaux de transition LiMnO 2, LiMn2O4, LiNiO2 ou LiCoO2. Si le compose LiCoO2 est relativement aise a synthetiser, il n'en demeure pas moins que le cobalt reste un metal plus couteux compare au nickel et au manganese. La synthese de LiNiO2, quart a elle, demeure un probleme du point de vue stoechiometrique. Un defaut de lithium (5 a 10% molaire) conduira a des proprietes electrochimiques mediocres de la batterie. Dans cette etude nous nous proposons donc de preparer par voie humide et par voie seche les materiaux d'electrode positive de la famille LiCoyNi1-yO2 aver (0 ≤ y ≤ 1) et d'etudier en detail l'influence du pourcentage de nickel et de cobalt sur les proprietes electrochimiques des oxydes mixtes Li-Ni-Co. Une des caracteristiques est la morphologie plus fine des poudres de materiaux, observes par microscopie electronique a balayage (MEB). Un traitement thermique a plus basse temperature (750°C) que pour LiCoO2 (850°C) ainsi qu'un leger exces de lithium dans la preparation, ont permis d'aboutir a un materiau de stoechiometrie quasi parfaite. Neanmoins, le role de pilfer joue par 2 a 4% de moles de Ni2+ presents sur les sites lithium, permet de conserver intacte la structure hexagonale de la maille entre deux cycles consecutifs. Afin de mieux comprendre l'influence du vieillissement dune demi-pile Li/LiMeO2 (Me = Ni, Co) a temperature ambiante, des etudes electrochimiques et d'impedance spectroscopique ont ete menees en parallele. Le vieillissement de la cellule s'accompagne seulement dune chute de son potentiel due a son auto

  8. Global dynamics analysis of nappe oscillation

    NASA Astrophysics Data System (ADS)

    De Rosa, Fortunato; Girfoglio, Michele; de Luca, Luigi

    2014-12-01

    The unsteady global dynamics of a gravitational liquid sheet interacting with a one-sided adjacent air enclosure, typically referred to as nappe oscillation, is addressed, under the assumptions of potential flow and absence of surface tension effects. To the purpose of shedding physical insights, the investigation examines both the dynamics and the energy aspects. An interesting re-formulation of the problem consists of recasting the nappe global behavior as a driven damped spring-mass oscillator, where the inertial effects are linked to the liquid sheet mass and the spring is represented by the equivalent stiffness of the air enclosure acting on the average displacement of the compliant nappe centerline. The investigation is carried out through a modal (i.e., time asymptotic) and a non-modal (i.e., short-time transient) linear approach, which are corroborated by direct numerical simulations of the governing equation. The modal analysis shows that the flow system is characterized by low-frequency and high-frequency oscillations, the former related to the crossing time of the perturbations over the whole domain and the latter related to the spring-mass oscillator. The low-frequency oscillations, observed in real life systems, are produced by the (linear) combination of multiple modes. The non-normality of the operator is responsible for short-time energy amplifications even in asymptotically stable configurations, which are confirmed by numerical simulations and justified by energy budget considerations. Strong analogies with the edge-tone problem are encountered; in particular, the integer-plus-one-quarter resonance criterion is uncovered, where the basic frequency to be multiplied by n + /1 4 is just the one related to the spacing among the imaginary parts of the eigenvalues.

  9. Downstream of downtown: urban wastewater as groundwater recharge

    NASA Astrophysics Data System (ADS)

    Foster, S. S. D.; Chilton, P. J.

    Wastewater infiltration is often a major component of overall recharge to aquifers around urban areas, especially in more arid climates. Despite this, such recharge still represents only an incidental (or even accidental) byproduct of various current practices of sewage effluent handling and wastewater reuse. This topic is reviewed through reference to certain areas of detailed field research, with pragmatic approaches being identified to reduce the groundwater pollution hazard of these practices whilst attempting to retain their groundwater resource benefit. Since urban sewage effluent is probably the only `natural resource' whose global availability is steadily increasing, the socioeconomic importance of this topic for rapidly developing urban centres in the more arid parts of Asia, Africa, Latin America and the Middle East will be apparent. L'infiltration des eaux usées est souvent la composante essentielle de toute la recharge des aquifères des zones urbaines, particulièrement sous les climats les plus arides. Malgré cela, une telle recharge ne constitue encore qu'un sous-produit incident, ou même accidentel, de pratiques courantes variées du traitement de rejets d'égouts et de réutilisation d'eaux usées. Ce sujet est passé en revue en se référant à certaines régions étudiées en détail, par des approches pragmatiques reconnues pour permettre de réduire les risques de pollution des nappes dues à ces pratiques tout en permettant d'en tirer profit pour leur ressource en eau souterraine. Puisque les effluents d'égouts urbains sont probablement la seule « ressource naturelle » dont la disponibilité globale va croissant constamment, l'importance socio-économique de ce sujet est évidente pour les centres urbains à développement rapide de l'Asie, de l'Afrique, de l'Amérique latine et du Moyen-Orient. La infiltración de aguas residuales es a menudo un componente principal de la recarga total en acuíferos ubicados en torno a zonas urbanas

  10. How to Select and Order NAPP and NHAP Photographs

    USGS Publications Warehouse

    ,

    2001-01-01

    The locations of aerial photographs from the National Aerial Photography Program (NAPP) and the National High Altitude Photography (NHAP) program are shown on flight-line indexes, which are available on microfiche or printed copy of microfiche.

  11. Hyperextension in the northern Caledonides: the Gargia nappe in Finnmark

    NASA Astrophysics Data System (ADS)

    Corfu, Fernando; Andersen, Torgeir B.

    2015-04-01

    Hyperextension stretches the lithosphere to the breaking point leading to the exhumation of serpentinized upper mantle peridotites, and the development of sedimentary basins and tectonic melange. The products of such processes are well documented along recent passive margins and in the Alps. Melange defines also a prominent nappe units extending along the southern Scandinavian Caledonides, where it is interpreted as the product of extension during formation of Iapetus (Andersen et al. 2012). In western Finnmark, northern Norway, a melange-type assemblage with km-size serpentinite bodies embedded in various metasedimentary rocks, schists and mylonitic units occurs in the Gargia nappe. The nappe overlies an autochthonous basement suite of Early Paleoproterozoic basalts and associated sedimentary rocks and its Neoproterozic sedimentary cover, including a tillite horizon. The Gargia nappe is itself overlain by the Kalak Nappe Complex, which in this region is composed mainly of psammites, likely deposited around 1000 Ma. The Kalak Nappe Complex contains the record of a multistage tectonic evolution with several episodes of magmatism and metamorphism between 900 and 550 Ma that paleogeographically do not fit the Archean to Paleoproterozoic evolution of the underlying autochthon of the Baltic Shield. Because of this recent new information, the postulation, in past decades, of an origin of the Kalak Nappe Complex from the Baltic margin has been problematic. The presence of exhumed mantle serpentinite bodies in the underlying Gargia Nappe, however, provides evidence for a truly allochthonus nature of the overlying nappes. The serpentinite mega-boudins of the Gargia Nappe are embedded in mica schists, hornblende schists, rare marbles, and mylonitic gneisses. Preliminary U-Pb geochronology indicates that the protoliths of the mylonitic gneisses are about 2830 Ma and probably were derived from the deformed basement gneisses, likely of Archean age, in the nappe. The time of

  12. Groundwater recharge and chemical evolution in the southern High Plains of Texas, USA

    NASA Astrophysics Data System (ADS)

    Fryar, Alan; Mullican, William; Macko, Stephen

    2001-11-01

    The unconfined High Plains (Ogallala) aquifer is the largest aquifer in the USA and the primary water supply for the semiarid southern High Plains of Texas and New Mexico. Analyses of water and soils northeast of Amarillo, Texas, together with data from other regional studies, indicate that processes during recharge control the composition of unconfined groundwater in the northern half of the southern High Plains. Solute and isotopic data are consistent with a sequence of episodic precipitation, concentration of solutes in upland soils by evapotranspiration, runoff, and infiltration beneath playas and ditches (modified locally by return flow of wastewater and irrigation tailwater). Plausible reactions during recharge include oxidation of organic matter, dissolution and exsolution of CO2, dissolution of CaCO3, silicate weathering, and cation exchange. Si and 14C data suggest leakage from perched aquifers to the High Plains aquifer. Plausible mass-balance models for the High Plains aquifer include scenarios of flow with leakage but not reactions, flow with reactions but not leakage, and flow with neither reactions nor leakage. Mechanisms of recharge and chemical evolution delineated in this study agree with those noted for other aquifers in the south-central and southwestern USA. Résumé. L'aquifère libre des Hautes Plaines (Ogallala) est le plus vaste aquifère des états-Unis et la ressource de base pour l'eau potable de la région semi-aride du sud des Hautes Plaines du Texas et du Nouveau-Mexique. Des analyses de l'eau et des sols prélevés au nord-est d'Amarillo (Texas), associées à des données provenant d'autres études dans cette région, indiquent que des processus intervenant au cours de l'infiltration contrôlent la composition de l'eau de la nappe libre dans la moitié septentrionale du sud des Hautes Plaines. Les données chimiques et isotopiques sont compatibles avec une séquence de précipitation épisodique, avec la reconcentration en solut

  13. Thermal history of the westernmost Eastern Alps (Penninic Rhenodanubian Flysch nappes, Helvetic nappes, and Subalpine Molasse thrust sheets)

    NASA Astrophysics Data System (ADS)

    Zerlauth, Michael; Bertrand, Audrey; Rantitsch, Gerd; Groß, Doris; Ortner, Hugo; Pomella, Hannah; Fügenschuh, Bernhard

    2016-07-01

    The frontal part of the westernmost Eastern Alps comprises from top to bottom of the Austroalpine and Penninic nappes, Ultrahelvetic slices, and two Helvetic thrust sheets, thrust upon the northern Alpine Molasse Basin. The thermal evolution of the Penninic Rhenodanubian Flysch nappes, the Helvetic nappes, and the allochthonous part of the Alpine Molasse Basin is constrained by vitrinite reflectance measurements and apatite fission track dating and implemented in a tectonic evolution scheme. Within the Helvetic nappes, vitrinite reflectance increases regionally from north to south and stratigraphically from the Campanian-Maastrichtian Wang Formation to the Toarcian Mols Member. Apatite fission track ages from Penninic and Subalpine Molasse units are consistently younger than the deposition age. They indicate therefore a post-depositional thermal overprint exceeding approximately 120 °C, the upper temperature limit of the apatite partial annealing zone. 1D thermal modelling suggests that the Penninic nappes attained deepest burial between the latest Cretaceous and Early Palaeocene with the Penninic basal thrust being located at approximately 8 km in the north compared to approximately 12 km in the south. Deepest burial of the upper Helvetic nappe occurred between the latest Eocene and Early Miocene. Its base was buried down to approximately 10.5 km in the north compared to 11.5 km in the south. Exhumation of the entire nappe stack started in the Early to Middle Miocene. For both Penninic and Helvetic models, a heatflow minimum during the Cenozoic deformation (max. 27-32 mW/m2), followed by an increase from the Middle Miocene onwards (up to 60 mW/m2), was assumed.

  14. A petrological and geochemical study of the Surna Nappe (Seve Nappe Complex?) in the Central Scandinavian Caledonides, Norway

    NASA Astrophysics Data System (ADS)

    Weigand, Silvia; Hauzenberger, Christoph; Gasser, Deta

    2016-04-01

    The Seve Nappe Complex, mainly outcropping and investigated in Sweden, comprises relics of Ordovician HP and UHP metamorphic rocks, which were overprinted by upper amphibolite facies metamorphism and anataxis during the Silurian. In Norway, in the hinterland of the Caledonian orogen, rocks of the Surna and Blåhø nappes are generally correlated with the Seve Nappe Complex. However, no detailed metamorphic studies are available from these units to compare it with the Seve Nappe Complex. The Surna and Blåhø nappes are located between the oceanic-derived Støren nappe and the continentally-derived Sætra nappe. Due to a strong post-Caledonian extensional and transtensional overprint and a close proximity to the MTFC (Møre-Trøndelag Fault Complex, a prominent post-Caledonian strike-slip fault complex) investigations of the early metamorphic history of the Surna and Blåhø nappes are challenging. In this contribution we present the results of a petrological and geochemical study of the Surna Nappe, from a ca. 10 km wide transect across this nappe west of Trondheim in Norway. The nappe is lithologically very heterogenous, consisting of quartz-rich mica-schists, amphibole-garnet-mica-schists, amphibolites, calcsilicates as well as pegmatites. Geochemically, the whole rock compositions vary from ultrabasic to acidic, but a distinction between metavolcanic and metasedimentary origin of the lithologies is not always straightforward. Although there are metabasic rocks present they do not show a mineral assemblage with a relic eclogite facies. Garnet occurs in several lithologies and is used together with plagioclase and biotite for conventional geothermobarometry using the TWQ and PET software tools. Additionally, Zr-in-rutile and garnet-biotite thermometers were applied. PT calculations from 18 different samples reveal PT conditions of 600 to 700°C and pressures of 10 to 16 kbar. The elevated phengite content in muscovite (Si up to 3.28) in a few samples may indicate

  15. Crustal imbrication and nappe folding in the southeastern Tauern Window

    NASA Astrophysics Data System (ADS)

    Hawemann, Friedrich; Gipper, Peter; Handy, Mark R.; Oberhänsli, Roland

    2013-04-01

    Metapelitic rocks in the cover of the European Basement exposed in the southeastern Tauern Window document a polyphase deformational history associated with Cenozoic subduction, accretion and exhumation along the European continental margin during Alpine Orogeny. The Mallnitz area is special in exposing almost all structural levels of the Alpine metamorphic edifice, including a stack of imbricated nappes derived from the European margin (Venediger Nappe System) that is separated by a roof thrust from overlying ophiolites of Alpine Tethys (Glockner Nappe). Our samples record four distinct phases of mineral growth and define a clockwise P-T path with two baric peaks that are separated by a period of decompression: (1) Pseudomorphs after lawsonite preserved within garnet clasts and predate the earliest schistosity in the area. These pseudomorphs are interpreted to document Paleogene accretion and subduction of a distal part of the European margin, possibly to blueschist-facies conditions; (2) Subsequent growth of a first generation of biotite and phengite forming the earliest schistosity indicate temperatures of about 560°C at 8 kbar. Chloritoid inclusions in garnet yield similar temperatures within error and are characteristic of amphibolite-facies conditions during isoclinal folding of the obducted nappes; (3) Newly formed staurolite and a second generation of micas characterize the second and main schistosity in the area which, together with continued garnet growth, indicate a second peak of metamorphism at 600°C and 9 kbar. We attribute this second baric peak to tectonic imbrication and thickening associated with the formation of the Venediger Nappe Complex. Subsequently, the nappe stack was exhumed in Late Paleogene time at nearly isothermal conditions. Cross micas overgrow the main schistosity and their recorded range of decreasing temperatures and pressures indicate ongoing exhumation and cooling in Neogene time. We relate this to upright folding and doming

  16. The metamorphic evolution of the Kathmandu Nappe area

    NASA Astrophysics Data System (ADS)

    Zhuk, Yuliya

    2016-04-01

    The Kathmandu Nappe area in central Nepal was initially discovered in the beginning of the 70s and mapped some years later. While the first investigation showed that the Kathmandu Nappe belonged to the less metamorphosed sedimentary and volcanic formations, later findings proved the Kathmandu Nappe to have a distinct lithology and stratigraphy with a separate metamorphic evolution. The aim of this project is to further investigate the geologic evolution of the area. The proposed method for investigation is to perform a detailed geological mapping of the area, collect rock samples based on the mapped information and analyse the samples using optical microscope analysis and zircon crystal morphology analysis. The Kathmandu Nappe forms a huge N100° synclinorium, divided into the lower Bhimpedi group, the Phulchauki group and the Cambrian-Ordovician granites. Detailed geological maps will be generated by focusing on the contact between the metasediment and Palung-, Ipa-, and Agragranite bodies. There are two expected findings. For one, the granite is expected to be younger than the metasediment, suggesting them to be caused by two different tectonic events. This would mean that the granite shows a clear intrusive relation with many pre-existing faults, and, therefore, that it was little affected by faulting. To prove or discard this, a detailed geological mapping will be used. For two, the granite is expected to have a crustal origin. This would mean that the magma generation probably occurred through anatexis of continental crust. To prove or discard this, the origin of the granite bodies will be identified and compared using optical microscope analysis and zircon crystal morphology.

  17. Nappe structure in a crustal scale duplex in Swat, Pakistan

    SciTech Connect

    Lawrence, R.D.; Snee, L.W.; Rosenberg, P.S.

    1985-01-01

    In the internal zone of thrust belts of continental collision orogens like the Himalaya metamorphic rocks of deep origin record penetrative ductile deformation. In Swat, Pakistan, this zone between the Indus suture and the sedimentary fold-and-thrust belt is narrower and tectonically simpler than elsewhere along the Himalayan orogenic belt. Here the authors have recognized large overturned, orthogneiss cored nappes of 15 km half wavelength. These are defined by para-amphibolite marker beds found in upright stratigraphic section above and in overturned section below the gneissic cores. They distinguish premetamorphic granite porphyry and tourmaline granite intruded into quartzose metasediments as gneissic cores of the nappes and a surrounding sequence of quartzites, amphibolites, and carbonates that were either deposited unconformably above the cores or premetamorphically thrust over them. Metamorphic isogrades cut across the nappe and /sup 40/Ar//sup 39/Ar hornblende dates indicate that metamorphic culmination occurred around 37-40 Ma at about 550/sup 0/C and at depths of about 20 km. These structures thus appear to predate the recognized age of metamorphism and thrusting of crystalline rocks on the MCT in the central Himalaya. They represent an early deep burial of the leading edge of the Indian shield by ophiolite slabs of oceanic lithosphere and/or the Kohistan island arc. By 30 Ma metamorphic temperatures (/sup 40/Ar//sup 39/Ar muscovite) had dropped to 320/sup 0/C, and the nappes were rising through the crust on underlying thrusts. The entire structure is very similar to that of the internal zone of the Alps, but such features have not previously been described in the Himalaya.

  18. The Ghomarides Nappes, Rif Coastal Range, Morocco: A Variscan chip in the Alpine Belt

    NASA Astrophysics Data System (ADS)

    Chalouan, Ahmed; Michard, André

    1990-12-01

    The Ghomarides nappes are the uppermost basement nappes in the Rifan Alpine belt. Paleozoic rocks constitute the prominent part of these nappes, together with Triassic and younger cover sediments. Four nappes are distinguished, each one with a distinct stratigraphical sequence, especially for the Devonian and Carboniferous periods. Sedimentological and structural arguments plead for an initial location on the northern margin of the African continent. The main folding and metamorphic events are shown to be Eo-Variscan (late Acadian). Tectonic vergence was to the north (present coordinates). Late Variscan (Hercynian) shortening gave upright, NW-SE trending folds. Alpine ductile overprints are scarce except at the base of the lowest nappe where K/Ar phengite ages are about 25 Ma. The Ghomarides nappes correlate with the Malaguides nappes (Betic Cordilleras, southern Spain), the Kabylian (northern Algeria) and Calabrian (southern Italy) Paleozoic nappes, the Tuscan-South-Alpine basement and the Upper Austro-Alpine nappes. The proposed correlations allow us to restaure the southern margin of the Hercynian belt along northwestern Africa.

  19. Groundwater capture processes under a seasonal variation in natural recharge and discharge

    NASA Astrophysics Data System (ADS)

    Maddock, Thomas, III.; Vionnet, Leticia Beatriz

    "Capture" is the increase in recharge and the decrease in discharge that occurs when pumping is imposed on an aquifer system that was in a previous state of approximate dynamic equilibrium. Regional groundwater models are usually used to calculate capture in a two-step procedure. A steady-state solution provides an initial-head configuration, a set of flows through the boundaries for the modeled region, and the initial basis for the capture calculation. The transient solutions provide the total change in flows through the boundaries. A difference between the transient and steady-state solutions renders the capture calculation. When seasonality is a modeling issue, the use of a single initial hydraulic head and a single set of boundary flows leads to miscalculations of capture. Instead, an initial condition for each season should be used. This approach may be accomplished by determining steady oscillatory solutions, which vary through the seasons but repeat from year to year. A regional groundwater model previously developed for a portion of the San Pedro River basin, Arizona, USA, is modified to illustrate the effect that different initial conditions have on transient solutions and on capture calculations. Résumé Les "prélèvements" sont constitués par l'augmentation de la recharge et par la diminution de l'écoulement qui se produit lorsqu'un pompage est imposéà un système aquifère qui était auparavant dans un état proche de l'équilibre dynamique. Les modèles régionaux de nappe sont en général utilisés pour calculer les prélèvements dans une procédure à deux étapes. Une solution en régime permanent donne la configuration piézométrique initiale, un jeu de conditions aux limites pour la région modélisée et les données de base pour le calcul des prélèvements. Les solutions transitoires donnent les modifications globales des conditions aux limites. Lorsque des variations saisonnières sont produites en sortie du modèle, le recours à une

  20. Origin of the Gargia Nappe in the northernmost Scandinavian Caledonides: Pre-Caledonian hyperextension or a traditional basement-cover nappe?

    NASA Astrophysics Data System (ADS)

    Corfu, Fernando; Andersen, Torgeir B.

    2016-04-01

    In western Finnmark of northern Norway, a melange-type assemblage with km-size serpentinite bodies embedded in various metasedimentary rocks, schists and mylonitic gneissic units occurs in the Gargia Nappe. The nappe overlies an autochthonous basement suite of Early Paleoproterozoic (ca. 2150 Ma) basalts and associated sedimentary rocks and its Neoproterozic sedimentary cover, including an Ediacaran (?) tillite. The Gargia Nappe is itself overlain by the Kalak Nappe Complex (KNC), which in this region is composed mainly of metasandstones, likely deposited around 1000 Ma. The KNC contains the record of a multistage tectonic evolution with several episodes of magmatism and metamorphism between 900 and 550 Ma that paleogeographically do not fit the Archean to Palaeoproterozoic evolution of the underlying autochthon of the Baltic Shield. Because of this new information, the postulation, in the past decades, of an origin of the KNC from the Baltic margin is considered problematic. The presence of serpentinised exhumed mantle peridotite bodies in the underlying Gargia Nappe, however, provides potential evidence for a truly allochthonous nature of the overlying nappes. The serpentinite mega-boudins of the Gargia Nappe are embedded in mica- and hornblende schists and rare marbles. They are structurally overlain by ancient felsic gneisses. New U-Pb geochronology on these mylonitic gneisses indicates that their protoliths in the nappe are ~2830 Ma. They were thus derived from a basement terrane of Archean age similar to the local Baltic shield of northernmost Scandinavia. The time of extension exhuming the mantle peridotites is still uncertain and is presently under investigation. We note, however, that the Gargia Nappe lies in the apparent extension of the Corrovarre Nappe, which is characterized by 610 Ma dykes, akin to those in the Sarek segment of the Seve Nappe further south. The two events may be related. We propose that the structural and lithological architecture of

  1. 3-D numerical models of viscous flow applied to fold nappes and the Rawil depression in the Helvetic nappe system (western Switzerland)

    NASA Astrophysics Data System (ADS)

    von Tscharner, M.; Schmalholz, S. M.; Epard, J.-L.

    2016-05-01

    The Helvetic nappe system exhibits three-dimensional (3-D) features such as the lateral variation in geometry between the Morcles and Doldenhorn fold nappes or the Rawil depression. We perform 3-D finite element simulations of linear and power-law viscous flow to investigate fold nappe formation during shortening of a half graben with laterally varying thickness. 3-D ellipsoids and corresponding 2-D intersection ellipses are used to quantify finite strain. Fold nappes which formed above a thicker graben have (i) larger amplitudes, (ii) a less sheared and thinned overturned limb, and (iii) a larger thickness than fold nappes formed above a thinner graben. These results agree with observations for the Morcles and Doldenhorn nappes. We also perform 3-D simulations for a tectonic scenario suggested for the evolution of the Rawil depression. The basement is shortened and extended laterally and includes a graben which is oblique to the shortening direction and acts as mechanical weak zone. The graben causes laterally varying basement uplift generating a depression whose amplitude depends on the graben orientation and the stress exponent of basement and sediments. The axial plunge of the depression is smaller (approximately 10°) than the observed plunge (approximately 30°) indicating that additional processes are required to explain the geometry of the Rawil depression.

  2. Nappe scale coherent block exhumation from eclogite-facies conditions revealed by Lu-Hf garnet chronometry - the Adula Nappe (Central Alps)

    NASA Astrophysics Data System (ADS)

    Sandmann, S.; Nagel, T. J.; Herwartz, D.; Kurzawski, R. M.

    2012-04-01

    The Adula Nappe in the Central Alps (Switzerland and Italy) is derived from the former continental margin of the European Plate that was subducted beneath the Adriatic Plate during the Alpine orogenic cycle. It mainly consists of various gneisses with layers of garnet-micaschist, marble, and bodies of mafic and locally of ultramafic rocks. High-pressure and ultra-high-pressure conditions are preserved in eclogite and ultramafic rocks but are virtually absent in gneisses and thus in the bulk of the nappe. It is unclear wether the unit was assembled after peak-pressure conditions from units with very different PTt-histories or was exhumed as a more or less coherent block from peak pressure conditions. Eclogite samples from the central Adula Nappe are characterised by the presence of two populations of garnet. A first generation of garnet shows a Variscan Lu-Hf age, a second one an Alpine (Late Eocene) age (Herwartz et al., 2011; this study). In the southern Adula Nappe Alpine metamorphic conditions completely reequilibrated Variscan assemblages and garnet reveals exclusivly Eocene Lu-Hf ages. In contrast, garnet was almost unaffected by Alpine metamorphism and is exclusively of Variscan age in the northern Adula Nappe. Hence, the degree of Alpine metamorphic overprint and Lu-Hf age reequilibration is maximal in the southern part of the unit and decreases towards the north. Isotopic ages are in line with microstructural observations and major element maps of garnet. Element maps display fully equilibrated garnet in the southern Adula Nappe, i.e. garnet with a homogeneous composition due to diffusive reequilibration of probably Alpine age. In the central Nappe, relicts of an older, partly requilibrated generation (Variscan), are overgrown by a garnet generation with prefectly preserved prograde zonation and no diffusive overprint during the Alpine cycle. Towards the northern Adula Nappe, the Alpine generation becomes less abundant and almost impossible to separate. As

  3. The Pan-African nappe tectonics in the Shackleton Range

    USGS Publications Warehouse

    Buggisch, W.; Kleinschmidt, G.

    2007-01-01

    In memory of Campbell Craddock: When J. Campbell Craddock (1972) published his famous 1:5 000 000 map of the Geology of Antarctica, he established major units such as the East Antarctic Craton, the early Palaeozoic Ross, the Mesozoic Ellsworth, and the Cenozoic Andean orogens. It is already evident from this map, that the strike of the Ellsworth Mountains and the Shackleton Range is perpendicular to palaeo-Pacific and modern Pacific margins. While the Ellsworth-Whitmore block is classified as a rotated terrane, the Ross-aged orogen of the Shackleton Range requires another interpretation. The discovery of extended tectonic nappes with south directed transport in the southern Shackleton Range and west transport in the north established a plate tectonic scenery with a subduction dominated Ross Orogen in the Transantarctic Mountains and a transpressive tectonic regime in the Shackleton Range during the final closing of the Mozambique Ocean.

  4. The importance of shear heating for shear localization during tectonic nappe displacement

    NASA Astrophysics Data System (ADS)

    Kiss, Dániel; Duretz, Thibault; Podladchikov, Yuri; Schmalholz, Stefan M.

    2016-04-01

    Localization of deformation plays a major role during tectonic processes at all scale, from the formation of deformation bands within single grains up to crustal and lithospheric scale shear zones. The role of shear localization is particularly important for the formation and displacement of tectonic nappes during orogeny. It has been shown that a simple one-dimensional (1D) thermo-mechanical shear zone model, which considers a power-law flow law and temperature dependent viscosity, can to the first-order explain thrust-sheet and fold nappe formation. This 1D model could successfully reproduce the overall shear strain distribution across natural nappes and shear zones, but underestimated systematically the shear strain at the base of the nappe and shear zone. This underestimation indicates that certain processes have been ignored in the analysis. We present therefore a new 1D thermo-mechanical model which also considers shear heating and the related thermal softening of temperature-dependent viscosity to quantify the impact of shear heating on strain localization during nappe displacement. We perform a dimensional analysis of the equations which describe the 1D shear zone model to determine the dimensionless parameters which control the deformation. Three deformation modes controlled by dimensionless parameters will be distinguished: (1) shear deformation for which shear heating is negligible, (2) shear deformation for which shear heating is moderate and displacement velocities stay in the range of plate velocities, (3) shear deformation for which shear heating is significant and velocities and temperatures increase continuously (thermal runaway). The 1D shear zone model is applied to the Helvetic nappe system in general and the Morcles, Doldenhorn and Wildhorn nappes in particular. For the geological and microstructural data available for the Helvetic nappe system we determine whether shear heating was important during nappe formation or not. The 1D results are

  5. Finite strains within recumbent folds of the kishorn Nappe, northwest Scotland

    NASA Astrophysics Data System (ADS)

    Potts, G. J.

    1982-10-01

    This study is based on the Torridonian and Cambro-Ordovician rocks of the Kishorn Nappe on the Isle of Skye and the adjacent mainland of Scotland. Grain shape fabric, Skolithos pipe shape analysis and palaeomagnetic techniques have been used to give an indication of the strain distribution and possible mechanisms involved in the generation of the recumbent folds within the Kishorn Nappe. Results indicate that recumbent folding has occurred without internal deformation.

  6. Discovery of microdiamond in the Åreskutan Nappe of the Seve Nappe Complex, overlying the COSC-1 drillhole

    NASA Astrophysics Data System (ADS)

    Klonowska, Iwona; Janák, Marian; Majka, Jarosław; ‎ Froitzheim, Nikolaus; Gee, David G.

    2015-04-01

    The Seve Nappe Complex (SNC) crops out for about 800 km along the Scandian mountain belt in northwestern Sweden. In the central Scandes of Jämtland and Tröndelag, the SNC has been mapped 200 km westards into the hinterland, via the Tömmerås and Trollheimen antiforms into the northern parts of the Western Gneiss Region. The Complex is dominated by psammitic metasediments and amphibolites derived from dolerites, basalts and gabbros (locally ultramafites) comprising an outer continental margin assemblage, inferred to represent the Cryogenian-Ediacaran, extended outer margin of Baltica. Although most of the SNC is in amphibolite facies, eclogites and garnet peridotites are locally preserved both in Sweden and farther west in Trollheimen. More pelitic metasediments occur at higher levels in the Complex and the high grade metamorphism is usually accompanied by partial melting and leucogranites. Isotope dating indicates that HP/UHP metamorphism is of mostly of Ordovician age and related to continent-arc subduction during closure of the Iapetus Ocean. In recent years, closer investigation of the high grade metamorphism has led not only to the identification of UHP assemblages in the eclogites and garnet peridotites (Janák et al. 2013, Klonowska et al. 2014), but also that the host paragneisses contain clear evidence of subduction (Majka et al. 2014), with microdiamond inclusions in garnet. Most recently on Åreskutan (Klonowska et al., this volume), on the mountain top above the COSC-1 drillhole, diamond-bearing gneisses have been found. Garnets in Åreskutan gneisses are characterized by inclusion-rich cores. Graphite, carbonates, quartz and CO2-fluid inclusions together with diamonds and moissanite are concentrated in swarms. Garnets are homogeneous, almandine-rich (Alm65-68Prp26-33Grs3-5Sps2-3). However, the highest grossular content is observed in garnet cores (5mol.%). Phengite is characterized by Si content of 3.19-3.47 apfu. Thermodynamic modelling indicates

  7. Dynamics of tectonic nappes: Thrusting versus intrusion or dynamic pressure versus lithostatic pressure

    NASA Astrophysics Data System (ADS)

    Markus Schmalholz, Stefan; Podladchikov, Yuri; Medvedev, Sergei

    2014-05-01

    Despite extensive research, the dynamics of tectonic nappes exhibiting high and ultra-high pressure ((U)HP) rocks is still debated. We classify existing models for nappe formation into two types, and refer to them as thrust and intrusion model. Thrust models approximate the orogen as wedge with a rigid buttress behind and a subducting lithospheric slab beneath. The dominant process of nappe formation is thrusting (brittle and/or ductile) that generates a dominant top-to-the-foreland shear sense. Rocks remain within crustal depth (<~60 km). Uplift and exhumation of (U)HP rocks is explained by underplating accompanied by isostatic uplift, extension in higher levels of the wedge and erosion. Thrust models can explain the imbricate nappe stacking and first-order structural observations in the Western Alps. However, in the last decades (U)HP rocks were found in nappes, and it is usually assumed that metamorphic pressure is a good indicator of maximum burial. This assumption represents a fundamental problem for the thrust model, namely to account for the large burial depth of (U)HP rocks indicating depths >100 km. Nappe formation at such mantle depths cannot be explained by the thrust model. In intrusion models (U)HP rocks are subducted to mantle depths and return to crustal depths by buoyancy driven or tectonically forced flow. Nappes are formed during the return flow with an opposite shear sense at the bottom and top of the nappe. Intrusion models could reproduce the first-order patterns of P-T-time paths of the Western Alps. However, there are problems with intrusion models. First, the intrusion scenario requires a major extensional shear zone in the hanging wall of the exhuming (U)HP unit. However, for most (U)HP units of the Western Alps the earliest coherent structures recorded along the upper boundary are top-to-the-foreland shear zones (consistent with thrust models). Second, dynamic intrusion models are usually unable to generate an imbricate nappe stack. The

  8. Contrasting metamorphic evolutions of metasediments from the Çine and Selimiye nappes in the Anatolide belt, western Turkey

    NASA Astrophysics Data System (ADS)

    Régnier, J. L.; Ring, U.; Passchier, C. W.; Güngör, T.

    2003-04-01

    Metasediments from the Çine and Selimiye nappes at the southern rim of the Anatolide belt of western Turkey record different metamorphic evolutions. The Eocene Selimiye shear zone separates both nappes. Relatively high-grade metasediments from the Çine nappe underneath the Selimiye shear zone record maximum P-T conditions of about 7 kbar and >550^oC. Metasediments from the overlying Selimiye nappe have maximum P-T conditions of 4 kbar and ˜525^oC near the base of the nappe. Kinematic indicators in both nappes are related to movement on the Selimiye shear zone and consistently show a top-S shear sense. Metamorphism in the Selimiye nappe decreases structural upwards as indicated by mineral isograds defining the garnet-chlorite zone at the base, the chloritoid-biotite zone and the biotite-chlorite zone at the top of the nappe. The mineral isograds in the Selimiye nappe run parallel to the regional SR foliation, parallel the Selimiye shear zone and indicate that the Selimiye shear zone formed during this prograde greenschist to lower amphibolite-facies metamorphic event but remained active after the peak of metamorphism. Protolith and 40Ar/39Ar mica dating, as well as tectonometamorphic relationships with the Eocene Cyclades-Menderes thrust, which occurs above the Selimiye nappe in the study area, suggest an Eocene age of metamorphism in the Selimiye nappe. Our preferred interpretation is that metamorphism in the metasediments of the Çine nappe directly below the Selimiye shear zone is of the same age. Metasediments of the Çine nappe 20-30 km north of the Selimiye shear zone record maximum P-T conditions of 8-11 kbar and 600-650^oC. Kinematic indicators show a top-N shear sense associated with prograde amphibolite-facies metamorphism. The age for amphibolite-facies metamorphism in this part of the Çine nappe is less clear. The tectonometamorphic fabric in orthogneiss, which underlies the metasediments of the Çine nappe is ˜550 Ma, and is cut by undeformed

  9. Contrasting metamorphic evolutions of metasediments from the Çine and Selimiye nappes in the Anatolide belt, western Turkey

    NASA Astrophysics Data System (ADS)

    Régnier, J. L.; Ring, U.; Passchier, C. W.; Güngör, T.

    2003-04-01

    Metasediments from the Çine and Selimiye nappes at the southern rim of the Anatolide belt of western Turkey record different metamorphic evolutions. The Eocene Selimiye shear zone separates both nappes. Relatively high-grade metasediments from the Çine nappe underneath the Selimiye shear zone record maximum P-T conditions of about 7 kbar and >550^oC. Metasediments from the overlying Selimiye nappe have maximum P-T conditions of 4 kbar and ˜525^oC near the base of the nappe. Kinematic indicators in both nappes are related to movement on the Selimiye shear zone and consistently show a top-S shear sense. Metamorphism in the Selimiye nappe decreases structural upwards as indicated by mineral isograds defining the garnet-chlorite zone at the base, the chloritoid-biotite zone and the biotite-chlorite zone at the top of the nappe. The mineral isograds in the Selimiye nappe run parallel to the regional SR foliation, parallel the Selimiye shear zone and indicate that the Selimiye shear zone formed during this prograde greenschist to lower amphibolite-facies metamorphic event but remained active after the peak of metamorphism. Protolith and 40Ar/39Ar mica dating, as well as tectonometamorphic relationships with the Eocene Cyclades-Menderes thrust, which occurs above the Selimiye nappe in the study area, suggest an Eocene age of metamorphism in the Selimiye nappe. Our preferred interpretation is that metamorphism in the metasediments of the Çine nappe directly below the Selimiye shear zone is of the same age. Metasediments of the Çine nappe 20--30 km north of the Selimiye shear zone record maximum P-T conditions of 8--11 kbar and 600--650^oC. Kinematic indicators show a top-N shear sense associated with prograde amphibolite-facies metamorphism. The age for amphibolite-facies metamorphism in this part of the Çine nappe is less clear. The tectonometamorphic fabric in orthogneiss, which underlies the metasediments of the Çine nappe is ˜550 Ma, and is cut by undeformed

  10. The Alpine nappe stack in western Austria: A crustal-scale cross-section

    NASA Astrophysics Data System (ADS)

    Pomella, Hannah; Bertrand, Audrey; Ortner, Hugo; Zerlauth, Michael; Fügenschuh, Bernhard

    2013-04-01

    A N-S oriented crustal-scale cross-section was constructed east of the Rhine valley in Vorarlberg, western Austria addressing the central Alps-eastern Alps boundary. The construction was based on published data, surface geology, drillings, as well as on reinterpreted seismic lines. The general architecture of the examined area can be described as a typical foreland fold-and-thrust belt, comprising the tectonic units of the Subalpine Molasse, (Ultra-)Helvetic, Penninic, and Austroalpine nappes. These units overthrusted the autochthonous Molasse along the south-dipping listric Alpine basal thrust. The thermotectonic evolution of this nappe stack is adressed by Bertrand et al. (this session). The Subalpine Molasse is multiply stacked, forming a triangle-zone (Müller et al. 1984). The shortening within the Subalpine Molasse in the cross section has been calculated using the Lower Marine Molasse as a reference and amounts to approx. 46 km, (~70%). Towards east the shortening within the Subalpine Molasse decreases dramatically as shown by Ortner et al. (this session). A well-defined seismic feature in the research area is the European basement together with its autochthonous cover, with a moderate southward dip from about 3500m BSL to approx. 6500m BSL along the ca. 50km long section. Several seismic sections show fault structures offsetting the top of the European basement as well as autochthonous cover. Another discontinuous double reflector that can be identified in several seismic sections is interpreted as the base of the Helvetic nappe complex (approx. at 5000m BSL in the southernmost parts). The internal structure of the Helvetic nappe stack could hardly be resolved. The assumed hinterland dipping duplex-structure of the Helvetic nappes results from surface and borehole-data. However, there are at least two Helvetic nappes needed to fill the available space. The deeper one, termed "Hohenemse nappe" (Wyssling, 1985), is overlain by the superficially exposed

  11. Basement lithostratigraphy of the Adula nappe: implications for Palaeozoic evolution and Alpine kinematics

    NASA Astrophysics Data System (ADS)

    Cavargna-Sani, Mattia; Epard, Jean-Luc; Bussy, François; Ulianov, Alex

    2014-01-01

    The Adula nappe belongs to the Lower Penninic domain of the Central Swiss Alps. It consists mostly of pre-Triassic basement lithologies occurring as strongly folded and sheared gneisses of various types with mafic boudins. We propose a new lithostratigraphy for the northern Adula nappe basement that is supported by detailed field investigations, U-Pb zircon geochronology, and whole-rock geochemistry. The following units have been identified: Cambrian clastic metasediments with abundant carbonate lenses and minor bimodal magmatism (Salahorn Formation); Ordovician metapelites associated with amphibolite boudins with abundant eclogite relicts representing oceanic metabasalts (Trescolmen Formation); Ordovician peraluminous metagranites of calc-alkaline affinity ascribed to subduction-related magmatism (Garenstock Augengneiss); Ordovician metamorphic volcanic-sedimentary deposits (Heinisch Stafel Formation); Early Permian post-collisional granites recording only Alpine orogenic events (Zervreila orthogneiss). All basement lithologies except the Permian granites record a Variscan + Alpine polyorogenic metamorphic history. They document a complex Paleozoic geotectonic evolution consistent with the broader picture given by the pre-Mesozoic basement framework in the Alps. The internal consistency of the Adula basement lithologies and the stratigraphic coherence of the overlying Triassic sediments suggest that most tectonic contacts within the Adula nappe are pre-Alpine in age. Consequently, mélange models for the Tertiary emplacement of the Adula nappe are not consistent and must be rejected. The present-day structural complexity of the Adula nappe is the result of the intense Alpine ductile deformation of a pre-structured entity.

  12. Estimating groundwater recharge

    USGS Publications Warehouse

    Stonestrom, David A.

    2011-01-01

    Groundwater recharge is the entry of fresh water into the saturated portion of the subsurface part of the hydrologic cycle, the modifier "saturated" indicating that the pressure of the pore water is greater than atmospheric.

  13. Tectonic significance of deformation patterns in granitoid rocks of the Menderes nappes, Anatolide belt, southwest Turkey

    NASA Astrophysics Data System (ADS)

    Gessner, Klaus; Piazolo, Sandra; Güngör, Talip; Ring, Uwe; Kröner, Alfred; Passchier, Cees

    Deformation fabrics in Proterozoic/Cambrian granitic rocks of the Çine nappe, and mid-Triassic granites of the Bozdag nappe constrain aspects of the tectonometamorphic evolution of the Menderes nappes of southwest Turkey. Based on intrusive contacts and structural criteria, the Proterozoic/Cambrian granitic rocks of the Çine nappe are subdivided into older orthogneisses and younger metagranites. The deformation history of the granitic rocks documents two major deformation events. An early, pre-Alpine deformation event (DPA) during amphibolite-facies metamorphism affected only the orthogneisses and produced predominantly top-to-NE shear-sense indicators associated with a NE-trending stretching lineation. The younger metagranites are deformed both by isolated shear zones, and by a major shear zone along the southern boundary of the Çine submassif. We refer to this Alpine deformation event as DA3. DA3 shear zones are associated with a N-trending stretching lineation, which formed during greenschist-facies metamorphism. Kinematic indicators associated with this stretching lineation reveal a top-to-south sense of shear. The greenschist-facies shear zones cut the amphibolite-facies structures in the orthogneisses. 207Pb/206Pb dating of magmatic zircons from a metagranite, which crosscuts orthogneiss containing amphibolite-facies top-to-NE shear-sense indicators, shows that DPA occurred before 547.2+/-1.0 Ma. Such an age is corroborated by the observation that mid-Triassic granites of the Çine and Bozdag nappes lack DPA structures. The younger, top-to-south fabrics formed most likely as a result of top-to-south Alpine nappe stacking during the collision of the Sakarya continent with Anatolia in the Eocene.

  14. The Alpine nappe stack in western Austria: a crustal-scale cross section

    NASA Astrophysics Data System (ADS)

    Pomella, Hannah; Ortner, Hugo; Zerlauth, Michael; Fügenschuh, Bernhard

    2015-04-01

    Based on an N-S-oriented crustal-scale cross section running east of the Rhine Valley in Vorarlberg, western Austria, we address the Alpine nappe stack and discuss the boundary between Central and Eastern Alps. For our cross section, we used surface geology, drillings and reinterpreted seismic lines, together with published sections. The general architecture of the examined area can be described as a typical foreland fold-and-thrust belt, comprising the tectonic units of the Subalpine Molasse, (Ultra-)Helvetic, Penninic and Austroalpine nappes. These units overthrusted the autochthonous Molasse along the south-dipping listric Alpine basal thrust. The European Basement, together with its autochthonous cover, dips gently towards the south and is dissected by normal faults and trough structures. The seismic data clearly show an offset not only of the top of the European Basement, but also of the Mesozoic cover and the Lower Marine Molasse. This indicates an activity of the structures as normal faults after the sedimentation of the Lower Marine Molasse. The Subalpine Molasse is multiply stacked, forming a triangle zone at the boundary with the foreland Molasse. The shortening within the Subalpine Molasse amounts to approximately 45 km (~67 %), as deduced from our cross section with the Lower Marine Molasse as a reference. The hinterland-dipping duplex structure of the Helvetic nappes is deduced from surface and borehole data. There are at least two Helvetic nappes needed to fill the available space between the Molasse below and the Northpenninic above. This is in line with the westerly located NRP20-East transect (Schmid et al., Tectonics 15(5):1047-1048, 1996; Schmid et al., The TRANSMED Atlas: the Mediterranean Region from Crust to Mantle, 2004), where the two Helvetic nappes are separated by the Säntis thrust. Yet in contrast to the Helvetic nappes in the NRP20-East transect, both of our Helvetic nappes comprise Cretaceous and Jurassic strata. This change is

  15. Ravia nappe, Bryan County, Oklahoma: a gravity slide block off the Tishomingo uplift

    SciTech Connect

    Jacobson, M.I.

    1983-08-01

    The Ravia nappe in Bryan County, Oklahoma, is located along the southwestern flank of the Tishomingo uplift, between the Cumberland and East Durant oil fields. This mass of Cambrian-Ordovician through Mississippian sediments tectonically overlies younger Springer shales (Pennsylvanian) of the Ardmore basin. Previously, this feature has been interpreted to have been thrust southward along the Cumberland fault, a fault parallel to the Ravia thrust. Reinterpretation of this area, with additional well data, indicates the Ravia nappe is a gravity slide block off the uplifted Tishomingo mountains. The Ravia nappe is interpreted to have been originally the southwest overturned limb of the Tishomingo uplift. Prior to the major thrusting on the Ravia thrust, but after compressional folding and uplift of the Tishomingo mountains, a breakaway fault formed across the most intensely folded beds. The breakaway fault undercut the overturned southwestern limb of the Tishomingo uplift in a concave-upward fault surface. Gravitational forces caused the Ravia nappe Mississippian Caney rocks to Cambrian-Ordoviciena Arbuckle rocks to slide rotationally southwestward 2.5 mi (4 km). Topographic relief prior to the slide may have been as much as 9000 ft (2700 m). The slide occurred sometime during late Morrowan to early Desmoinesian.

  16. Cyclic frictional-viscous slip oscillations along the base of an advancing nappe complex: Insights into brittle-ductile nappe emplacement mechanisms from the Naukluft Nappe Complex, central Namibia

    NASA Astrophysics Data System (ADS)

    Viola, Giulio; Mancktelow, Neil S.; Miller, Jodie A.

    2006-06-01

    The Naukluft Nappe Complex (NNC) forms a far-traveled fold and thrust belt klippe of the Panafrican Damara Belt in central Namibia. Estimates of the SE directed displacement range between 50 and 80 km. The entire nappe stack was thrust along an out-of-sequence, nearly planar, horizontal structure, the "Naukluft Thrust." The thrust zone consists of several distinct lithological components whose typical distribution, when all present, from bottom to top is (1) a massive, ochre-yellow weathering dolomite; (2) a polymict "gritty dolomite" (called in the past "Sole Dolomite"), (3) strongly foliated and isoclinally folded calcmylonites, and (4) an upper massive dolomite. A very discrete (<50 mm thick, often <10 mm thick) planar brittle fault (component 5) can occur at any level within this sequence. Our investigations show that the gritty dolomite forms by progressive cataclasis of the massive dolomite (component 1). Moreover, clasts of gritty dolomite are observed randomly oriented within a similar gritty dolomite matrix, suggesting multiple pulses of brecciation and self-brecciation. The gritty dolomite locally forms injection veins into the calcmylonites, and these veins are themselves boudinaged, indicating broadly coeval cataclastic and ductile deformation. The evolution of structures within the thrust zone is linked to the presence and flow of overpressured pore fluids. Field observations suggest that several pulses of fluid-induced brittle deformation overprinted, in a cyclic fashion, ductile structures formed during the emplacement of the nappe edifice. A "fault valve" behavior is suggested for the basal detachment of the NNC, with bulk shortening being accommodated by incremental slip during a history of combined viscous and frictional flow.

  17. Demonstrating induced recharge

    SciTech Connect

    Caswell, B. )

    1990-03-01

    This paper describes an attempt by a New England community to explore for an aquifer that would yield 1 million gallons of ground water per day. After the discovery of a glacial sand and gravel aquifer, a demonstration of a hydraulic coupling between the aquifer and an adjacent stream was undertaken. This connection was needed to maintain recharge capacity of the well. The paper goes on to describe the techniques needed and used to determine the induced recharge caused by drawdown in these test wells.

  18. Rechargeable lithium cell

    NASA Astrophysics Data System (ADS)

    Salomon, M.; Plichta, E. J.

    1984-09-01

    The general object of this invention is to provide an improved rechargeable lithium cell. A more specific object of the invention is to provide a rechargeable lithium cell having an improved low temperature performance and rate capability. It has now been found that the aformentioned objects can be attained using lithium as the anode, a solution of a lithium salt such as LiF6 or LiAlC14 in a mixed organic solvent as the electrolyte and a lithium intercalating cathode.

  19. The Sumba enigma: Is Sumba a diapiric fore-arc nappe in process of formation?

    NASA Astrophysics Data System (ADS)

    Audley-Charles, M. G.

    1985-10-01

    The anomalous updomed morphological expression of Sumba island, its enigmatic lack of strong Neogene deformation and the northward morphological indentation of southern Sumbawa and Flores require explanation. The stratigraphy of Sumba may be correlated with the Cretaceous to Miocene part of the Timor allochthon. The sedimentary and eruptive rock succession in Sumba shows remarkable similarities with the allochthonous Palelo, Wiluba and Cablac deposits of Timor. In both islands the Cretaceous parts of these sequences are regarded as characteristic of fore-arc deposits built on thin continental crust. The Timor nappe is interpreted as a 5 km thick tectonic flake of the Banda fore-arc thrust onto the Australian continental margin in the mid-Pliocene collision. The postulated Sumba nappe has not yet been thrust onto the Australian margin which, in the Sumba region, has not yet converged as close to the arc as in the Timor area. The postulated Sumba nappe is interpreted as a diapiric elongated dome of the Sunda fore-arc that is being squeezed by the converging margin of Australia against the volcanic islands of Sumbawa and Flores. The absence of indications on the seismic reflection profiles for the presence of the thrust fault of the Sumba nappe may perhaps be explained by the thrusts being nearly horizontal within flat-lying strata. The Savu thrust is correlated with the probably older (pre-Late Pliocene) Wetar Suture as a major southward dipping lithospheric rupture. East of 124°E, this suture does not seem to have moved much since the mid-Pliocene collision that emplaced the nappes on Timor. However, microearthquake data suggest some activity is continuing.

  20. Structural development of the Tso Morari ultra-high pressure nappe of the Ladakh Himalaya

    NASA Astrophysics Data System (ADS)

    Epard, Jean-Luc; Steck, Albrecht

    2008-04-01

    A continental subduction-related and multistage exhumation process for the Tso Morari ultra-high pressure nappe is proposed. The model is constrained by published thermo-barometry and age data, combined with new geological and tectonic maps. Additionally, observations on the structural and metamorphic evolution of the Tso Morari area and the North Himalayan nappes are presented. The northern margin of the Indian continental crust was subducted to a depth of > 90 km below Asia after continental collision some 55 Ma ago. The underthrusting was accompanied by the detachment and accretion of Late Proterozoic to Early Eocene sediments, creating the North Himalayan accretionary wedge, in front of the active Asian margin and the 103-50 Ma Ladakh arc batholith. The basic dikes in the Ordovician Tso Morari granite were transformed to eclogites with crystallization of coesite, some 53 Ma ago at a depth of > 90 km (> 27 kbar) and temperatures of 500 to 600 °C. The detachment and extrusion of the low density Tso Morari nappe, composed of 70% of the Tso Morari granite and 30% of graywackes with some eclogitic dikes, occurred by ductile pure and simple shear deformation. It was pushed by buoyancy forces and by squeezing between the underthrusted Indian lithosphere and the Asian mantle wedge. The extruding Tso Morari nappe reached a depth of 35 km at the base of the North Himalayan accretionary wedge some 48 Ma ago. There the whole nappe stack recrystallized under amphibolite facies conditions of a Barrovian regional metamorphism with a metamorphic field gradient of 20 °C/km. An intense schistosity with a W-E oriented stretching lineation L 1 and top-to-the E shear criteria and crystallization of oriented sillimanite needles after kyanite, testify to the Tso Morari nappe extrusion and pressure drop. The whole nappe stack, comprising from the base to top the Tso Morari, Tetraogal, Karzok and Mata-Nyimaling-Tsarap nappes, was overprinted by new schistosities with a first N

  1. Studies on the structural variations of pentosan polysulfate sodium (NaPPS) from different sources by capillary electrophoresis.

    PubMed

    Degenhardt, M; Ghosh, P; Wätzig, H

    2001-01-01

    Commercial pentosan polysulfate sodium salts (NaPPS) are highly sulfated polysaccharides derived from beechwood hemicellulose by sulfate esterification with a Mrel range of 1500-6000. The polysaccharide backbone of NaPPS consists of repeating linear units of 1-4 linked beta-D-xylopyranose with laterally substituted 4-methylglucopyranosyluronic acid units glycosidically linked to the 2 position of the main chain at every 10th xylopyranose unit on average. For many years NaPPS has been used for antithrombotic prophylaxis in Europe and interstitial cystitis in the USA and Australia. More recently NaPPS has found veterinary application for the treatment of osteoarthritis and related conditions in domestic animals and is registered for this use in Australia, New Zealand, Canada, UK, Eire, and several Scandanavian countries. At present the use of NaPPS for human disorders is confined to material manufactured by one company. However, for veterinary applications, NaPPS from three manufactures have been described. Since it is well known that the biological activities of sulfated polysaccharides are dependent on their molecular structures we considered it important to characterise these various NaPPS preparations using an established method of analysis. Unfortunately, traditional analytical techniques such as TLC, OR, UV/Vis spectroscopy, and size exclusion chromatography were incapable of providing structural information which would distinguish these NaPPS preparations from each other. In contrast, a capillary zone electrophoresis (CZE) method facilitated characterisation of the different NaPPS by a highly reproducible fingerprint, using a benzene-1,2,4-tricarboxylic acid buffer (8.75 mmol/L, pH = 4.9) with indirect UV detection (lambda = 217 nm) and a special capillary pre-treatment (1 M NaOH for 1 h at 25 degrees C, then running buffer for 120 min at 25 degrees C applying -20 kV). In the present study more than 20 batches of NaPPS from the three manufacturers have been

  2. REMOTELY RECHARGEABLE EPD

    SciTech Connect

    Vrettos, N; Athneal Marzolf, A; Scott Bowser, S

    2007-11-13

    Radiation measurements inside the Contact Decon Maintenance Cell (CDMC) in the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) are required to determine stay times for personnel. A system to remotely recharge the transmitter of an Electronic Personnel Dosimeter (EPD) and bail assembly to transport the EPD within the CDMC was developed by the Savannah River National Laboratory (SRNL) to address this need.

  3. Rechargeable Magnesium Power Cells

    NASA Technical Reports Server (NTRS)

    Koch, Victor R.; Nanjundiah, Chenniah; Orsini, Michael

    1995-01-01

    Rechargeable power cells based on magnesium anodes developed as safer alternatives to high-energy-density cells like those based on lithium and sodium anodes. At cost of some reduction in energy density, magnesium-based cells safer because less susceptible to catastrophic meltdown followed by flames and venting of toxic fumes. Other advantages include ease of handling, machining, and disposal, and relatively low cost.

  4. Evolution of quartz microstructures and textures during thrusting of the Kalak nappe complex

    NASA Astrophysics Data System (ADS)

    Marti, Sina; Kern, Nicola; Stünitz, Holger; Kilian, Rüdiger; Heilbronner, Renée; Menegon, Luca

    2013-04-01

    The Kalak nappe of Northern Norway shows penetrative Caledonian shear deformation related to the Scandian collison. Deformation took place under retrograde metamorphic conditions of amphibolite to greenschist facies and locally preserved low strain lenses show relics of pre-Caledonian granulite facies assemblages. Thus, the Kalak nappe represents a detached segment of pre-Caledonian lower crust. Along the E6 at Langfjord and Altafjord south of the Seiland Igneous Province, a transect through the lower part of the Kalak nappe and the contact to the underlying parautochthonous (PA) unit is studied. While the Kalak units consist of metapelites, mafics, metapsammites, and metagranitoids, the PA units consist largely of low grade micaschists and carbonates. We analyzed dynamic quartz microstructures and textures in conjunction with the metamorphic gradient from the PA across the thrust into higher nappe units. From the structurally higher units down towards the thrust contact, dominant recrystallization mechanisms change from grain boundary migration recrystallization (GBM) to grain boundary migration accompanied with subgrain rotation recrystallization (GBM+SGR) to subgrain rotation recrystallization (SGR). Corresponding mean recrystallized grain sizes decrease from ~ 340 μm (GBM) to ~ 180 μm (GBM+SGR) to ~ 60 μm (SGR). In the lowest grade rocks, domains are found where SGR recrystallization overprints an earlier GBM microstructure. Changes in quartz [c]-axis pole figures accompany the change in dominant recrystallization mechanism from distinct maxima in the y-direction for the GBM regime to peripheral maxima (with large angles to the foliation) in the SGR regime. Together with the fabric changes, the Kalak nappe shows a retrograde metamorphic evolution from ~ 700 to 570 ° C, 1.2 to 0.9 GPa and dominant GBM recrystallization to GBM+SGR at ~ 580 - 500 ° C, 1 to 0.9 GPa to dominant SGR below 500 ° C, 0.7 GPa and increasing strain localization during nappe

  5. Extension in the Aegean nappe-stacks: Numerical Model and their Geological Validation

    NASA Astrophysics Data System (ADS)

    Lecomte, E.; Huet, B.; Le Pourhiet, L.; Labrousse, L.; Jolivet, L.

    2010-12-01

    After mountain building, the crust exhibits complex structure. Especially, thickening achieved by nappe-stacking induces rheological heterogenities at all scales: from the fault scale up to the crustal scale. This process is likely to influence post-orogenic evolution. However, it is generally not considered in numerical models. In this study, we consider the impact of pre-existing thrusts and nappes structures on the mode of post-orogenic extension. We focus on thermomechanical modeling of reactivation of convergent structures inherited from compression. The Aegean domain that experienced extension after the formation of the Hellenides is considered as a natural laboratory. Natural data are used to constrain a priori the geometry and rheology of the models and to validate them a posteriori. Three problems at different scales are considered. Firstly, we model the reactivation of a thrust as a low angle normal fault. Recent studies show that Aegean detachments were active in the brittle field with very shallow dips. These observations are in contradiction with the classical fault mechanics theory. In order to reconcile both point of view, we propose a new model by introducing an elasto-plastic frictional fault gouge that is able to compact. Our models show that plastic strain on badly oriented faults is favored by compaction of the fault gouge. Secondly, we model the formation of the Corinth rift. The Phyllite-Quartizte nappe is introduced in the upper crust as a weak shallow-dipping layer between the Pindos and Tripolitza massive carbonate nappes. The competence contrast between this nappe and its surrounding controls the dynamics of rifting. High competence contrast leads to the formation of crustal-scale planar faults rooting on the brittle ductile transition of the crust and thin-skinned listric faults rooting on the nappe itself. This model is consistent with the observed microseismicity patterns, the asymmetry of the Corinth Gulf, and the kinematics of fault

  6. From nappe stacking to exhumation: Cretaceous tectonics in the Apuseni Mountains (Romania)

    NASA Astrophysics Data System (ADS)

    Reiser, Martin Kaspar; Schuster, Ralf; Spikings, Richard; Tropper, Peter; Fügenschuh, Bernhard

    2016-05-01

    New Ar-Ar muscovite and Rb-Sr biotite age data in combination with structural analyses from the Apuseni Mountains provide new constraints on the timing and kinematics of deformation during the Cretaceous. Time-temperature paths from the structurally highest basement nappe of the Apuseni Mountains in combination with sedimentary data indicate exhumation and a position close to the surface after the Late Jurassic emplacement of the South Apuseni Ophiolites. Early Cretaceous Ar-Ar muscovite ages from structurally lower parts in the Biharia Nappe System (Dacia Mega-Unit) show cooling from medium-grade conditions. NE-SW-trending stretching lineation and associated kinematic indicators of this deformation phase (D1) are overprinted by top-NW-directed thrusting during D2. An Albian to Turonian age (110-90 Ma) is proposed for the main deformation (D2) that formed the present-day geometry of the nappe stack and led to a pervasive retrograde greenschist-facies overprint. Thermochronological and structural data from the Bihor Unit (Tisza Mega-Unit) allowed to establish E-directed differential exhumation during Early-Late Cretaceous times (D3.1). Brittle detachment faulting (D3.2) and the deposition of syn-extensional sediments indicate general uplift and partial surface exposure during the Late Cretaceous. Brittle conditions persist during the latest Cretaceous compressional overprint (D4).

  7. Recharge into a shingle beach

    NASA Astrophysics Data System (ADS)

    Keating, T.

    1984-04-01

    Traditionally, groundwater recharge in the U.K. has been calculated by the Penman method on a monthly basis, using values of potential evaporation derived from averaged meteorological data and monthly totals of rainfall. Recent work by K.W.F. Howard and J.W. Lloyd has shown that these monthly totals considerably underestimate recharge calculated over shorter time periods and they suggested that 1-day, or at worst, 10-day intervals should be used. In this paper field experiments to measure recharge into a shingle beach are reported. These experiments were made with a lysimeter over a 6-yr. period and have shown that recharge into the shingle occurs whenever significant precipitation occurs, even during the summer months. The Penman model is shown to be unrealistic for estimating recharge into such a beach and an alternative model for calculating recharge is proposed. This model is shown to yield good results.

  8. Tectonic overpressure may reconcile the structural and petrological records of the Adula nappe (Central Alps)

    NASA Astrophysics Data System (ADS)

    Pleuger, Jan; Podladchikov, Yuri

    2014-05-01

    The Penninic Alps are the result of progressive underthrusting of oceanic and continental domains below the Adriatic microplate. Situated in the internal part of the Alpine orogen, they expose basement and thinned cover nappes which have been metamorphosed to variable degree, among them several units which were subjected to ultrahigh-pressure metamorphism. Due to the more or less strong nappe-internal deformation of these units, cross sections through the Penninic Alps cannot be restored kinematically by area or line balancing techniques. Instead, such restorations attempt to consistently reconcile geochronological and structural data and petrological pressure-temperature estimates. Pressure data are usually converted into depth assuming that they were lithostatic which puts the ultrahigh-pressure units to subcrustal depths. Tectonic exhumation of a unit from such a depth by whatever mechanism requires a large-scale normal fault with several tens of kilometres of displacement in the hanging wall of the unit. However, for all Penninic ultrahigh-pressure units (Dora Maira unit, Zermatt-Saas zone, Monviso unit, Adula-Cima Lunga nappe), the oldest mappable post-peak-pressure structures are related to top-to-the-foreland shearing, i.e. thrusting. There are two potential solutions to this dilemma. The first one is that either the exhumation was indeed accommodated by a large-scale normal fault which became completely overprinted during later deformational stages. The other one is that peak pressures were not lithostatic. To our knowledge, the first solution is applied to all kinematic models of the Alps so far. In order to explore the feasibility of the second solution, we performed a purely structural restoration of the NFP20-East cross section without lithostatic pressure-to-depth-conversions. This cross-section comprises the ultrahigh-pressure Adula nappe (up to ca. 30 kbar) and relies on quantitative strain data from the overlying units. The result shows that, in

  9. Reinterpretation of nappe structures in the Central Alps Evidence from 3D foliation field modelling

    NASA Astrophysics Data System (ADS)

    Maxelon, M.; Mancktelow, N. S.

    2003-04-01

    The Lepontine Alps represent the classic region for both, fold nappe development at mid-crustal levels and fold interference patterns from outcrop to regional scale. They have also been proposed as models for rapid burial and exhumation. However, before such models can be applied or critically assessed, the geometry of the units involved must be accurately known in three dimensions and this is a challenging task in this complex region. The three-dimensional geometry of the Lepontine nappes is not established unequivocally, as the integration and visualisation of structural data reflecting at least five different deformation phases has not yet been achieved satisfactorily. The present study focusses on a combination of new structural mapping in critical and/or contradictory areas, existing observations and their geostatistical assessment with modern computer-based tools (Editeur Géologique, Gocad) in order to develop a testable three-dimensional model of the geometry of the Lepontine Nappes in the Central Alps. Here we present a regional-scale three dimensional model of the southern central part of the Lepontine Region, bordered by the Swiss-Italian frontier in the east and Valle Leventina to the west and by Biasca and Locarno to the north and south. The model visualises a geostatistical calculation of the dominant foliation field in three dimensions, based on field measurements. The present day tectonostratigraphy and nappe geometry are mainly influenced by the three earliest recognisable Alpine deformation phases D_1 to D_3. D_1 structures are associated with first-time crustal nappe emplacement. Lithologies that are interpreted as nappe separators - mainly Mesozoic sediments such as "Bündnerschiefer" - have mostly been interleaved between the nappes during D_1, which entails strong isoclinal folding and pronounced boudinage of the infolded lithologies, with the development of a penetrative foliation S_1. S_1 and the infolded Mesozoic have been intensely

  10. Detrital zircon data support a Timanian origin for the Kalak Nappe Complex, North Norwegian Caledonides

    NASA Astrophysics Data System (ADS)

    Andresen, Arild; Agyei-Dwarko, Nana; Steltenpohl, Mark

    2014-05-01

    Detrital zircon data support a Timanian origin for the Kalak Nappe Complex, North Norwegian Caledonides. Arild Andresen, Nana Yaw Agyei-Dwarko & Mark G. Steltenpohl The origin of the Kalak Nappe Complex (KNC) in the Arctic Caledonides of Norway is historically enigmatic. Psammitic rocks of the KNC traditionally are thought to have been derived from the thinned, rifted margin of western Baltica. Recently, it has been proposed that U-Pb ages on detrital zircon and on magmatic zircon from the many intrusives present in KNC suggest derivation from Laurentian (Kirkland et al. 2007) and peri-Gondwanan (Corfu et al. 2011) realms. In this contribution we argue for a third alternative. Our LA-ICP-MS U-Pb ages on detrital zircon from the Ediacaran and Lower Paleozoic deposits (Dividal Group) in northern Scandinavia indicate that their source region was the Timanian Orogen, formed along Baltica`s northeastern margin in the Late Neoproterozoic. A large proportion of the detrital zircon grains from the Ediacaran-Cambrian deposits range in age between c. 1.7 and 1.0 Ga, but a distinct population of c. 0.57 Ga old-detrital zircon is also present in several samples. The source areas for these Late Paleoproterozoic and younger zircons are unknown from northeastern Fennoscandia, but are, however, known from basement rocks (Timanides) below the Pechora Basin in NW Russia and thus is a fingerprint for sediments derived from the Timanides. Psammitic units of the allochthonous Kalak Nappe Complex (KNC) have zircon-age populations similar to those from the Dividal Group with the exception of the 0.57 Ga zircons. If, however, the detrital zircon dates from the KNC are mixed with detrital zircons from the c. 0.57 Ga Sørøy Igneous Complex, then an almost identical zircon age population should be expected. Instead of arguing for a Laurentian or peri-Gondwana origin of KNC, as some authors do, we prefer to link the KNC to the Timanides, preferentially the northwestern part of the present

  11. FLUIDIC: Metal Air Recharged

    ScienceCinema

    Friesen, Cody

    2016-07-12

    Fluidic, with the help of ARPA-E funding, has developed and deployed the world's first proven high cycle life metal air battery. Metal air technology, often used in smaller scale devices like hearing aids, has the lowest cost per electron of any rechargeable battery storage in existence. Deploying these batteries for grid reliability is competitive with pumped hydro installations while having the advantages of a small footprint. Fluidic's battery technology allows utilities and other end users to store intermittent energy generated from solar and wind, as well as maintain reliable electrical delivery during power outages. The batteries are manufactured in the US and currently deployed to customers in emerging markets for cell tower reliability. As they continue to add customers, they've gained experience and real world data that will soon be leveraged for US grid reliability.

  12. FLUIDIC: Metal Air Recharged

    SciTech Connect

    Friesen, Cody

    2014-03-07

    Fluidic, with the help of ARPA-E funding, has developed and deployed the world's first proven high cycle life metal air battery. Metal air technology, often used in smaller scale devices like hearing aids, has the lowest cost per electron of any rechargeable battery storage in existence. Deploying these batteries for grid reliability is competitive with pumped hydro installations while having the advantages of a small footprint. Fluidic's battery technology allows utilities and other end users to store intermittent energy generated from solar and wind, as well as maintain reliable electrical delivery during power outages. The batteries are manufactured in the US and currently deployed to customers in emerging markets for cell tower reliability. As they continue to add customers, they've gained experience and real world data that will soon be leveraged for US grid reliability.

  13. The Gaissa Nappe, Finnmark, North Norway: an example of a deeply eroded external imbricate zone within the Scandinavian Caledonides

    NASA Astrophysics Data System (ADS)

    Townsend, C.; Roberts, D.; Rice, A. H. N.; Gayer, R. A.

    The Lower Allochthon of the Caledonides of Finnmark, northern Norway, is represented solely by the Gaissa Nappe, which is composed of sub-greenschist facies sedimentary rocks of late Riphean to Tremadoc age. The lithostratigraphic sequence has been shortened by thrusting and folding in an ESE direction. Based on mapping and structural profiling east of Porsangerfjord, the Gaissa Nappe can be divided into four structural segments: the Børsely duplex, developed beneath the Kalak Nappe of the Middle Allochthon, is oblique to an imbricate fan, the Munkavarri imbricate zone, east of which is the Guiverassa duplex zone that is partly covered by the Vuonjalrassa thrust sheet. The sole thrust to the Gaissa Nappe is a flat planar surface which truncates the common N-S folds and associated cleavage in the rocks of the Gaissa Nappe. The Vuonjalrassa-Gaissa thrust cuts down section in the transport direction, possibly as a result of early tectonic downwarping. A balanced cross-section and a hanging-wall diagram have been partially restored, indicating that the metasediments of the trailing edge of the Munkavarri imbricate zone have been displaced by 104 km in their ESE translation direction. Taking the sequence west of Porsangerfjord into consideration, an overall contraction of more than 150 km is possible. In the east, it is argued that the basal Gaissa décollement, formerly thought to die out and pass laterally into an unconformity, extends to the northeast beyond the head of Tanafjord. Folds that occur in front of the sole thrust on the Varanger Peninsula imply the presence of a blind thrust. In an orogenic context, the Gaissa Nappe forms a series of imbricated thrust sheets in the external part to the collision belt, produced during the Finnmarkian orogenic event in late Cambrian to early Ordovician time.

  14. Dual-porosity modeling of groundwater recharge: testing a quick calibration using in situ moisture measurements, Areuse River Delta, Switzerland

    NASA Astrophysics Data System (ADS)

    Alaoui, Abdallah; Eugster, Werner

    A simple method for calibrating the dual-porosity MACRO model via in situ TDR measurements during a brief infiltration run (2.8 h) is proposed with the aim of estimating local groundwater recharge (GR). The recharge was modeled firstly by considering the entire 3 m of unsaturated soil, and secondly by considering only the topsoil to the zero-flux plane (0-0.70 m). The modeled recharge was compared against the GR obtained from field measurements. Measured GR was 313 mm during a 1-year period (15 October 1990-15 October 1991). The best simulation results were obtained when considering the entire unsaturated soil under equilibrium conditions excluding the macropore flow effect (330 mm), whereas under non-equilibrium conditions GR was overestimated (378 mm). Sensitivity analyses showed that the investigation of the topsoil is sufficient in estimating local GR in this case, since the water stored below this depth appears to be below the typical rooting depth of the vegetation and is not available for evapotranspiration. The modeled recharge under equilibrium conditions for the 0.7-m-topsoil layer was found to be 364 mm, which is in acceptable agreement with measurements. Une méthode simple pour la calibration du modèle à double porosité MACRO par des mesures TDR in situ durant un bref essai d'infiltration (2.8 h) a été proposée pour l'estimation locale de la recharge de la nappe (RN). La RN a été d'abord simulée en tenant compte de toute la zone non saturée (3 m) et ensuite, en considérant uniquement la couverture du sol entre zéro et le plan du flux nul (0.70 m). La RN simulée a été comparée à la RN observée. La RN mesurée durant une année (15 octobre 1990-15 octobre 1991) était de 313 mm. Les meilleures simulations ont été obtenues en tenant compte de toute la zone non saturée sous les conditions d'équilibre excluant le flux préférentiel (330 mm). Sous les conditions de non équilibre, la RN a été surestimée (378 mm). Les analyses de

  15. Kinematics of the Central Taurides during Neotethys closure and collision, the nappes in the Sultan Mountains, Turkey

    NASA Astrophysics Data System (ADS)

    Güngör, Talip

    2013-07-01

    In the Central Taurides, the Sultan Mountains comprise in ascending order the Çimendere unit and the Akşehir, Doğanhisar, Çay nappes composed of metasedimentary sequences deposited from Cambrian to Tertiary. The overthrust of the Çay nappe on the Lutetian Celeptaş formation representing the uppermost stratigraphic position in the Çimendere unit indicates that the latest nappe emplacement occurred during the Middle Eocene. The Oligocene and Miocene rocks are in post-tectonic facies in the west Central Taurides. The kinematic data from these nappes related to closure of the Neotethys reveal a top-NE shear sense in the northwest part and a top-SE shear sense in the southeast part of the Sultan Mountains. The Sultan Mountains are located in the north part of the Isparta Angle which was tectonically assembled by the Lycian, Hoyran-Beyşehir-Hadim and Antalya allochthons on the Bey Dağları and Anamas-Akseki autochthons from the Latest Cretaceous to the Late Pliocene. The previous paleomagnetic data showed that the west and east subsections of the Isparta Angle were subjected to post-Eocene 30°-40° anticlockwise and clockwise rotations, respectively. In consideration of these paleomagnetic data, the kinematic data measured in the Sultan Mountains might be restored into approximately E-W-trending linear fabric associated with a top-E shear sense. These new kinematic data from the nappes in the Sultan Mountains disagree with the existing tectonic models that suggest N-S nappe translation over the Central Taurides during the latest Cretaceous-Middle Eocene. The alternative tectonic model for the Antalya nappes in the core of the Isparta Angle related to east-west compression suggests westward and eastward nappe emplacements on the surrounding autochthons. However, the new kinematic data presented here point consistently to a top-E shear sense in all tectonostratigraphic units in the Sultan Mountains currently located in the north part of the Anamas

  16. How does shear zone nucleate? An example from the Suretta nappe (Swiss Eastern Alps)

    NASA Astrophysics Data System (ADS)

    Goncalves, Philippe; Poilvet, Jean-Charles; Oliot, Emilien; Trap, Pierre; Marquer, Didier

    2016-05-01

    In order to address the question of the processes involved during shear zone nucleation, we present a petro-structural analysis of millimetre-scale shear zones within the Roffna rhyolite (Suretta nappe, Eastern central Alps). Field and microscopic evidences show that ductile deformation is localized along discrete fractures that represent the initial stage of shear zone nucleation. During incipient brittle deformation, a syn-kinematic metamorphic assemblage of white mica + biotite + epidote + quartz precipitated at ca. 8.5 ± 1 kbar and 480 ± 50 °C that represent the metamorphic peak conditions of the nappe stacking in the continental accretionary wedge during Tertiary Alpine subduction. The brittle to ductile transition is characterized by the formation of two types of small quartz grains. The Qtz-IIa type is produced by sub-grain rotation. The Qtz-IIb type has a distinct CPO such that the orientation of c-axis is perpendicular to the shear fracture and basal and rhombhoedric slip systems are activated. These Qtz-IIb grains can either be formed by recrystallization of Qtz-IIa or by precipitation from a fluid phase. The shear zone widening stage is characterized by a switch to diffusion creep and grain boundary sliding deformation mechanisms. During the progressive evolution from brittle nucleation to ductile widening of the shear zone, fluid-rock interactions play a critical role, through chemical mass-transfer, metasomatic reactions and switch in deformation mechanisms.

  17. Microstructural and fabric studies from the rocks of the Moine Nappe, Eriboll, NW Scotland

    NASA Astrophysics Data System (ADS)

    Evans, D. J.; White, S. H.

    Microstructures and quartz c-axis fabric diagrams from mylonites and psammitic Moine schists, collected in traverses across the lower levels of the Moine Nappe in the Eriboll area, are presented. On approaching the Moine Thrust from the Kyle of Tongue, the following microstructural sequence is encountered: interlayered coarse grained biotite psammitic and schistose tectonites being in part mylonitic with two platy slide zones, one containing biotite and the other only muscovite and chlorite and both showing quartz microstructures indicative of post-tectonic relaxation; these pass into more mylonitic rocks nearer the thrust zone which in turn passes into the main chlorite-grade mylonite belt and finally, adjacent to the Moine Thrust, into reworked lower chlorite grade mylonites. Although there is some local variation, the overall quartz c-axis fabric is an incomplete asymmetric type I girdle. The main variation is the development of type II girdles in the reworked, ultrafine grained mylonites. The extent of the mylonitization is more extensive than previously reported. Studies of folds within the mylonite belt have revealed eye structures and small-scale folds; many are sheath folds. They cannot be unequivocally correlated with large-scale recumbent folds within the Moine Nappe. The results presented indicate that mylonitization is not limited to a single phase, and raises the possibility that there may be earlier Caledonian or possibly Precambrian structural elements present in the Eriboll region Moines prior to much of the mylonitization.

  18. Basement-cover relationships in the Tambo nappe (Central Alps, Switzerland): geometry, structure and kinematics

    NASA Astrophysics Data System (ADS)

    Baudin, Thierry; Marquer, Didier; Persoz, Francis

    1993-05-01

    In the Pennine zone of the Central Alps, the Tambo nappe forms a thin crystalline sliver embedded in the Mesozoic cover. Four Tertiary Alpine deformations are observed. The D1 ductile deformation is linked to the progressive Eocene stacking of the nappes towards the northwest. During D1, basement deformation is governed by imbricate tectonics whereas cover is thin-skinned and intensively folded. These different structures reflect the original strong rheological contrast between basement and cover. During the heterogeneous and ductile D2 deformation, the behaviour of the basement and cover became similar. The strong vertical D2 shortening, associated with a 'top-to-the-east' shear, led to the folding of the prior SE-dipping structures, developing SE-vergent folds with axes close to the E-W L2 stretching lineation. D2 corresponds to post-collisional crustal thinning following D2 crustal thickening. The D3 and D4 deformations occurred under retrograde conditions and can be correlated with uplift and late dextral movement on the Insubric line, respectively.

  19. Water-induced fabrics of olivine in peridotites from the Lindas Nappe, Bergen arc, western Norway

    NASA Astrophysics Data System (ADS)

    Jung, Sejin; Jung, Haemyeong; Austrheim, Hâkon

    2010-05-01

    The Bergen Arc, western Norway is composed of several units distributed in an arc shape. Lindas Nappe is one of these units. Two peridotite outcrops in Lindas Nappe anorthosite complex were studied to understand deformation conditions of olivine. A mylonite zone was found in the peridoties and deformation fabrics of small olivine in the area were also studied. Lattice preferred orientation (LPO) of olivine was determined using the electron backscattered diffraction (EBSD) in SEM. Water content of olivine in the samples was measured using the Fourier transformation infrared (FTIR) spectroscopy. We observed three different types of LPOs (E-, B-, and A-type) of olivine in a large grain area. Sample (372) showed that [100] axes of olivine are aligned subparallel to the lineation and [001] axes aligned normal to the foliation, which is known as E-type LPO of olivine (Jung et al., 2006). Three samples (375, 380, and 381) showed that [001] axes of olivine are aligned subparallel to the lineation and [010] axes aligned normal to the foliation, which is known as B-type LPO of olivine. Another sample (379) in the large grain area showed that [100] axes of olivine are aligned subparallel to the lineation and [010] axes aligned normal to the foliation, which is known as A-type LPO of olivine. On the other hand, we observed two types of LPOs of olivine in a mylonite zone with a small grain-size: B- and C-type. C-type LPO is characterized as [001] axes of olivine aligned subparallel to the lineation and [100] axes of olivine aligned nearly normal to the foliation. Previous experimental study showed that B-, C-, and E-type LPO patterns were observed in a wet condition and A-type LPO was observed in a dry condition (Jung et al., 2006). FTIR analysis of olivine revealed that a sample showing the A-type LPO showed only small IR absorption peaks in the range of wave numbers 3000 - 3750 cm-1. In contrast, samples showing B-, C-, and E-type LPO showed large IR absorption peaks in the

  20. How does shear zone nucleate? An example from the Suretta nappe (Swiss Eastern Alps)

    NASA Astrophysics Data System (ADS)

    Goncalves, Philippe; Poilvet, Jean-Charles; Oliot, Emilien; Trap, Pierre; Marquer, Didier

    2016-05-01

    In order to address the question of the processes involved during shear zone nucleation, we present a petro-structural analysis of millimetre-scale shear zones within the Roffna rhyolite (Suretta nappe, Eastern central Alps). Field and microscopic evidences show that ductile deformation is localized along discrete fractures that represent the initial stage of shear zone nucleation. During incipient brittle deformation, a syn-kinematic metamorphic assemblage of white mica + biotite + epidote + quartz precipitated at ca. 8.5 ± 1 kbar and 480 ± 50 °C that represent the metamorphic peak conditions of the nappe stacking in the continental accretionary wedge during Tertiary Alpine subduction. The brittle to ductile transition is characterized by the formation of two types of small quartz grains. The Qtz-IIa type is produced by sub-grain rotation. The Qtz-IIb type has a distinct CPO such that the orientation of c-axis is perpendicular to the shear fracture and basal and rhombhoedric slip systems are activated. These Qtz-IIb grains can either be formed by recrystallization of Qtz-IIa or by precipitation from a fluid phase. The shear zone widening stage is characterized by a switch to diffusion creep and grain boundary sliding deformation mechanisms. During the progressive evolution from brittle nucleation to ductile widening of the shear zone, fluid-rock interactions play a critical role, through chemical mass-transfer, metasomatic reactions and switch in deformation mechanisms.

  1. Functional materials for rechargeable batteries.

    PubMed

    Cheng, Fangyi; Liang, Jing; Tao, Zhanliang; Chen, Jun

    2011-04-19

    There is an ever-growing demand for rechargeable batteries with reversible and efficient electrochemical energy storage and conversion. Rechargeable batteries cover applications in many fields, which include portable electronic consumer devices, electric vehicles, and large-scale electricity storage in smart or intelligent grids. The performance of rechargeable batteries depends essentially on the thermodynamics and kinetics of the electrochemical reactions involved in the components (i.e., the anode, cathode, electrolyte, and separator) of the cells. During the past decade, extensive efforts have been dedicated to developing advanced batteries with large capacity, high energy and power density, high safety, long cycle life, fast response, and low cost. Here, recent progress in functional materials applied in the currently prevailing rechargeable lithium-ion, nickel-metal hydride, lead acid, vanadium redox flow, and sodium-sulfur batteries is reviewed. The focus is on research activities toward the ionic, atomic, or molecular diffusion and transport; electron transfer; surface/interface structure optimization; the regulation of the electrochemical reactions; and the key materials and devices for rechargeable batteries. PMID:21394791

  2. Reusable Energy and Power Sources: Rechargeable Batteries

    ERIC Educational Resources Information Center

    Hsiung, Steve C.; Ritz, John M.

    2007-01-01

    Rechargeable batteries are very popular within consumer electronics. If one uses a cell phone or portable electric tool, she/he understands the need to have a reliable product and the need to remember to use the recharging systems that follow a cycle of charge/discharge. Rechargeable batteries are being called "green" energy sources. They are a…

  3. Choosing appropriate techniques for quantifying groundwater recharge

    USGS Publications Warehouse

    Scanlon, B.R.; Healy, R.W.; Cook, P.G.

    2002-01-01

    Various techniques are available to quantify recharge; however, choosing appropriate techniques is often difficult. Important considerations in choosing a technique include space/time scales, range, and reliability of recharge estimates based on different techniques; other factors may limit the application of particular techniques. The goal of the recharge study is important because it may dictate the required space/time scales of the recharge estimates. Typical study goals include water-resource evaluation, which requires information on recharge over large spatial scales and on decadal time scales; and evaluation of aquifer vulnerability to contamination, which requires detailed information on spatial variability and preferential flow. The range of recharge rates that can be estimated using different approaches should be matched to expected recharge rates at a site. The reliability of recharge estimates using different techniques is variable. Techniques based on surface-water and unsaturated-zone data provide estimates of potential recharge, whereas those based on groundwater data generally provide estimates of actual recharge. Uncertainties in each approach to estimating recharge underscore the need for application of multiple techniques to increase reliability of recharge estimates.

  4. Organic facies characteristics of the Carboniferous Pamucakyayla Formation, western Taurus, Antalya Nappes, Kemer (Antalya/Turkey)

    NASA Astrophysics Data System (ADS)

    Bertan Gulludag, Cevdet; Altunsoy, Mehmet; Ozcelik, Orhan

    2015-04-01

    The study area is located in the western part of the Taurus Belt (SW Turkey). This region exhibits a complex structure involving two autochthonous units surrounded and imbricated with three allochthonous complexes. Antalya Nappes is a complex tectonic imbricate structure including sedimantary and ultrabasic rocks. In this study, organic facies characteristics of Carboniferous coaly units in the Pamucakyayla region (Kemer, Antalya-Turkey) were examined. The Carboniferous Pamucakyayla Formation, which is characterized by sandstone, claystone, marl and coaly units. This units includes different levels of coal seams in different thicknesses. Organic matter is composed predominantly of woody and amorphous material, with a minor contribution of planty and coaly material. Kerogen in the deposits is type II/III, as indicated by organic petrographic observations and Rock-Eval data. Total organic carbon (TOC) values are generally between 0.01 and 1.44 %, but reach 5.81 % in the formation. Tmax values vary between 446 and 451 °C and indicate mature zone (Based on the value of 0.25 % TOC). Organic facies type BC, C and CD were identified in the investigated units. Organic facies BC is related sandstoneand marl lithofacies. This facis is deposited under an anoxic water column in a fine grained clastics, where rapid deposition creates anoxia in the sediments after deposition. This facies is characterized by average values of HI around 317 (equivalent to type II kerogene), TOC around 0.02 %, and an average of S2 of 0.04 mg HC/g of rock. Organic facies C is related to sandstone, marl and coal lithofacies. This facies is characterized by average values of HI around 176 (equivalent to type III kerogene), TOC around 0.19 %, and an average of S2 of 0.03 mg HC/g of rock. The organic matter is partly oxidized, and terrestrial. Organic facies C is the "gas-prone" facies. Organic facies CD is related to limestone, marl and coal lithofacies. This facies is characterized by average values

  5. First evidence of UHP metamorphism within the Seve Nappe Complex of central Sweden

    NASA Astrophysics Data System (ADS)

    Majka, J.; Janák, M.; Gee, D. G.; Van Roermund, H. L. M.; Verbaas, J.

    2012-04-01

    The first evidence of UHP metamorphism in the Seve Nappe Complex of northern Jämtland, central Swedish Caledonides, was discovered in 2010 (Majka & Janák 2011). The UHP parageneses occur within a kyanite-bearing eclogite, forming part of a metabasic dyke that truncates an orogenic garnet peridotite body. This kyanite-eclogite provides key information about the peak UHP metamorphic conditions and subsequent granulite facies overprint. The garnet peridotite body is located close to lake Friningen, northeast of the town Gäddede. The metabasic dyke consists predominantly of a bi-mineralic garnet pyroxenite (Cpx=diopside); however this dominant composition locally "grades" into that of the kyanite-eclogite described here. The kyanite-eclogite is composed of coarse grained garnet and omphacite, with minor kyanite. Garnet occurs in three varieties: large (< 1 cm), small (< 100 µm) and tiny lamellae within omphacite. In terms of chemistry the three garnet varieties reveal similar compositions (XPrp = 0.40-0.44, XGrs = 0.25-0.29, XAlm = 0.29-0.33; XSps = 0.01). Large garnets commonly contain inclusions of omphacite, kyanite, zoisite, rutile, quartz, amphibole and rare phengite. Omphacite (25% of Jd and 2.6% of Ca-Eskola components) exhibits rods of SiO2 and kyanite, which are crystallographically oriented and are interpreted as exsolutions. A set of retrogressive microtextures is represented by symplectites of diopside + plagioclase (after omphacite), sapphirine+spinel+corundum (after kyanite) and, together with orthopyroxene and diopside, defining lower pressure granulite facies assemblages. The calculated peak P-T metamorphic conditions, obtained from Grt-Omp-Ky-Phn geothermobarometry and confirmed by pseudosection modelling, are 2.9-3.5 GPa and 720-822 °C, clearly falling inside the coesite stability field. The retrograde granulite facies overprint occurred at 0.8-1.0 GPa and 750-850 °C, constrained by pseudosection. Brueckner & Van Roermund (2007) reported a Sm

  6. Hydrocarbon possibilities of concealed Mesozoic-Paleogene sediments below Himalayan nappes - reappraisal

    SciTech Connect

    Acharyya, S.K.; Ray, K.K.

    1982-01-01

    Hydrocarbon exploration of the Ganga (Ganges) and Sub-Himalayan basins indicates the presence of upper Neogene-Quaternary continental molasse and the absence of Paleogene sediments regarded as hydrocarbon source beds. Marine to brackish water Paleogene-lower Neogene sediments, closely fringing the Sub-Himalayan foothills, increase in thickness northward. Their presence and facies in the frontal schuppen zone and in the Lesser Himalayan windows, commonly in close association with upper Mesozoic shelf sediments, indicate a formerly greater width for the late Mesozoic-early Neogene shelf-miogeosynclinal basin. The pre-Tertiary rocks of the Lesser Himalayas are in nappes floored by the flat-lying sole thrust redesignated the Main Boundary thrust (MBT). Schuppen structure and lateral shortening complicate the geometry of the MBT. Pre-Tertiary tectonic grain and metamorphism, ubiquitously developed within the Lesser Himalayan cover rocks, are typically absent in the subjacent Paleogene-lower Neogene window-zone sediments. This opinion is corroborated by a few oil and gas shows from the Eocene limestone outcrops close to the MBT and also from the Lesser Himalayan pre-Tertiary metamorphic cover rocks.

  7. Evidence for dilution of deep, confined ground water by vertical recharge of isotopically heavy Pleistocene water

    SciTech Connect

    Siegel, D.I. )

    1991-05-01

    New analyses of the isotopic composition of water, {sup 14}C-dating of dissolved inorganic carbon, and order-of-magnitude Darcy calculations suggest that a dilute body of water, trending north-south in the Cambrian-Ordovician aquifer of Iowa, was emplaced as vertical recharge of Pleistocene-age water from the base of the Des Moines lobe of late Wisconsin time. The recharge occurred through more than 300 m of overlaying Silurian to Mississippian age rocks. The {delta}{sup 18}O values range from {minus}10{per thousand} to {minus}9{per thousand} for the dilute water body and are consistent with a mixture of Des Moines lobe meltwater and precipitation found today in the north-central US. These results suggest that (1) the climate at the end of the last glaciation was mild and (2) a ground-water stable isotope signature similar to that of modern precipitation in an aquifers recharge area is not a priori evidence for relatively recent recharge.

  8. Rechargeable Aluminum-Ion Batteries

    SciTech Connect

    Paranthaman, Mariappan Parans; Liu, Hansan; Sun, Xiao-Guang; Dai, Sheng; Brown, Gilbert M

    2015-01-01

    This chapter reports on the development of rechargeable aluminum-ion batteries. A possible concept of rechargeable aluminum/aluminum-ion battery based on low-cost, earth-abundant Al anode, ionic liquid EMImCl:AlCl3 (1-ethyl-3-methyl imidazolium chloroaluminate) electrolytes and MnO2 cathode has been proposed. Al anode has been reported to show good reversibility in acid melts. However, due to the problems in demonstrating the reversibility in cathodes, alternate battery cathodes and battery concepts have also been presented. New ionic liquid electrolytes for reversible Al dissolution and deposition are needed in the future for replacing corrosive EMImCl:AlCl3 electrolytes.

  9. Electrically rechargeable REDOX flow cell

    NASA Technical Reports Server (NTRS)

    Thaller, L. H. (Inventor)

    1976-01-01

    A bulk energy storage system is designed with an electrically rechargeable reduction-oxidation (REDOX) cell divided into two compartments by a membrane, each compartment containing an electrode. An anode fluid is directed through the first compartment at the same time that a cathode fluid is directed through the second compartment. Means are provided for circulating the anode and cathode fluids, and the electrodes are connected to an intermittent or non-continuous electrical source, which when operating, supplies current to a load as well as to the cell to recharge it. Ancillary circuitry is provided for disconnecting the intermittent source from the cell at prescribed times and for circulating the anode and cathode fluids according to desired parameters and conditions.

  10. Research on rechargeable oxygen electrodes

    NASA Technical Reports Server (NTRS)

    Giner, J.; Malachesky, P. A.; Holleck, G.

    1971-01-01

    Studies were carried out on a number of factors which may influence the behavior of the platinum electrocatalyst of oxygen electrodes for use in rechargeable metal-oxygen batteries or hydrogen-oxygen fuel cells. The effects of pretreatments for various potentials and added ionic species, which could be present in such systems, were studied with reguard to: (1) the state of surface oxidation, (2) platinum dissolution, (3) the kinetics of oxygen evolution and reduction (including the role of hydrogen peroxide), and (4) changes in porous electrode structure. These studies were carried out on smooth platinum, platinized platinum, and Teflon-bonded platinum black electrodes in carefully purified electrolyte solutions. The main factors which appear to affect rechargeable oxygen electrode performance and life are: (1) the buildup of a refractory anodic layer on extended cycling, and (2) the dissolution of platinum.

  11. Recharge Data for Hawaii Island

    DOE Data Explorer

    Nicole Lautze

    2015-01-01

    Recharge data for Hawaii Island in shapefile format. The data are from the following sources: Whittier, R.B and A.I. El-Kadi. 2014. Human Health and Environmental Risk Ranking of On-Site Sewage Disposal systems for the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii – Final, Prepared for Hawaii Dept. of Health, Safe Drinking Water Branch by the University of Hawaii, Dept. of Geology and Geophysics. Oki, D. S. 1999. Geohydrology and Numerical Simulation of the Ground-Water Flow System of Kona, Island of Hawaii. U.S. Water-Resources Investigation Report: 99-4073. Oki, D. S. 2002. Reassessment of Ground-water Recharge and Simulated Ground-Water Availability for the Hawi Area of North Kohala, Hawaii. U.S. Geological Survey Water-Resources Investigation report 02-4006.

  12. Iron-Air Rechargeable Battery

    NASA Technical Reports Server (NTRS)

    Narayan, Sri R. (Inventor); Prakash, G.K. Surya (Inventor); Kindler, Andrew (Inventor)

    2014-01-01

    Embodiments include an iron-air rechargeable battery having a composite electrode including an iron electrode and a hydrogen electrode integrated therewith. An air electrode is spaced from the iron electrode and an electrolyte is provided in contact with the air electrode and the iron electrodes. Various additives and catalysts are disclosed with respect to the iron electrode, air electrode, and electrolyte for increasing battery efficiency and cycle life.

  13. Survey of rechargeable battery technology

    SciTech Connect

    Not Available

    1993-07-01

    We have reviewed rechargeable battery technology options for a specialized application in unmanned high altitude aircraft. Consideration was given to all rechargeable battery technologies that are available commercially or might be available in the foreseeable future. The LLNL application was found to impose very demanding performance requirements which cannot be met by existing commercially available battery technologies. The most demanding requirement is for high energy density. The technology that comes closest to providing the LLNL requirements is silver-zinc, although the technology exhibits significant shortfalls in energy density, charge rate capability and cyclability. There is no battery technology available ``off-the-shelf` today that can satisfy the LLNL performance requirements. All rechargeable battery technologies with the possibility of approaching/meeting the energy density requirements were reviewed. Vendor interviews were carried out for all relevant technologies. A large number of rechargeable battery systems have been developed over the years, though a much smaller number have achieved commercial success and general availability. The theoretical energy densities for these systems are summarized. It should be noted that a generally useful ``rule-of-thumb`` is that the ratio of packaged to theoretical energy density has proven to be less than 30%, and generally less than 25%. Data developed for this project confirm the usefulness of the general rule. However, data shown for the silver-zinc (AgZn) system show a greater conversion of theoretical to practical energy density than would be expected due to the very large cell sizes considered and the unusually high density of the active materials.

  14. Estimate of regional groundwater recharge rate in the Central Haouz Plain, Morocco, using the chloride mass balance method and a geographical information system

    NASA Astrophysics Data System (ADS)

    Ait El Mekki, Ouassil; Laftouhi, Nour-Eddine; Hanich, Lahoucine

    2015-09-01

    Located in the extreme northwest of Africa, the Kingdom of Morocco is increasingly affected by drought. Much of the country is characterised by an arid to semi-arid climate and the demand for water is considerably higher than the supply, particularly on the Haouz Plain in the centre of the country. The expansion of agriculture and tourism, in addition to industrial development and mining, have exacerbated the stress on water supplies resulting in drought. It is therefore necessary to adopt careful management practices to preserve the sustainability of the water resources in this region. The aquifer recharge rate in the piedmont region that links the High Atlas and the Central Haouz Plain was estimated using the chloride mass balance hydrochemical method, which is based on the relationship between the chloride concentrations in groundwater and rainwater. The addition of a geographical information system made it possible to estimate the recharge rate over the whole 400 km2 of the study area. The results are presented in the form of a map showing the spatialized recharge rate, which ranges from 13 to 100 mm/year and the recharge percentage of the total rainfall varies from 3 to 25 % for the hydrological year 2011-2012. This approach will enable the validation of empirical models covering areas >6200 km2, such as the Haouz nappe.

  15. Charge Characteristics of Rechargeable Batteries

    NASA Astrophysics Data System (ADS)

    Maheswaranathan, Ponn; Kelly, Cormac

    2014-03-01

    Rechargeable batteries play important role in technologies today and they are critical for the future. They are used in many electronic devices and their capabilities need to keep up with the accelerated pace of technology. Efficient energy capture and storage is necessary for the future rechargeable batteries. Charging and discharging characteristics of three popular commercially available re-chargeable batteries (NiCd, NiMH, and Li Ion) are investigated and compared with regular alkaline batteries. Pasco's 850 interface and their voltage & current sensors are used to monitor the current through and the potential difference across the battery. The discharge current and voltage stayed fairly constant until the end, with a slightly larger drop in voltage than current, which is more pronounced in the alkaline batteries. After 25 charge/discharge cycling there is no appreciable loss of charge capacities in the Li Ion battery. Energy densities, cycle characteristics, and memory effects will also be presented. Sponsored by the South Carolina Governor's school for Science and Mathematics under the Summer Program for Research Interns program.

  16. Groundwater recharge and agricultural contamination

    USGS Publications Warehouse

    Böhlke, J.K.

    2002-01-01

    Agriculture has had direct and indirect effects on the rates and compositions of groundwater recharge and aquifer biogeochemistry. Direct effects include dissolution and transport of excess quantities of fertilizers and associated materials and hydrologic alterations related to irrigation and drainage. Some indirect effects include changes in water-rock reactions in soils and aquifers caused by increased concentrations of dissolved oxidants, protons, and major ions. Agrilcultural activities have directly or indirectly affected the concentrations of a large number of inorganic chemicals in groundwater, for example NO3-, N2, Cl, SO42-, H+, P, C, K, Mg, Ca, Sr, Ba, Ra, and As, as well a wide variety of pesticides and other organic compounds. For reactive contaminants like NO3-, a combination of chemical, isotopic, and environmental-tracer analytical approaches might be required to resolve changing inputs from subsequent alterations as causes of concentration gradients in groundwater. Groundwater records derived from multi-component hydrostratigraphic data can be used to quantify recharge rates and residence times of water and dissolved contaminants, document past variations in recharging contaminant loads, and identify natural contaminant-remediation processes. These data indicate that many of the world's surficial aquifers contain transient records of changing agricultural contamination from the last half of the 20th century. The transient agricultural groundwater signal has important implications for long-term trends and spatial heterogeneity in discharge.

  17. Groundwater recharge and agricultural contamination

    NASA Astrophysics Data System (ADS)

    Böhlke, John-Karl

    2002-02-01

    Agriculture has had direct and indirect effects on the rates and compositions of groundwater recharge and aquifer biogeochemistry. Direct effects include dissolution and transport of excess quantities of fertilizers and associated materials and hydrologic alterations related to irrigation and drainage. Some indirect effects include changes in water-rock reactions in soils and aquifers caused by increased concentrations of dissolved oxidants, protons, and major ions. Agricultural activities have directly or indirectly affected the concentrations of a large number of inorganic chemicals in groundwater, for example NO3 -, N2, Cl, SO4 2-, H+, P, C, K, Mg, Ca, Sr, Ba, Ra, and As, as well as a wide variety of pesticides and other organic compounds. For reactive contaminants like NO3 -, a combination of chemical, isotopic, and environmental-tracer analytical approaches might be required to resolve changing inputs from subsequent alterations as causes of concentration gradients in groundwater. Groundwater records derived from multi-component hydrostratigraphic data can be used to quantify recharge rates and residence times of water and dissolved contaminants, document past variations in recharging contaminant loads, and identify natural contaminant-remediation processes. These data indicate that many of the world's surficial aquifers contain transient records of changing agricultural contamination from the last half of the 20th century. The transient agricultural groundwater signal has important implications for long-term trends and spatial heterogeneity in discharge.

  18. Basement nappes on the NE boundary the Ossa-Morena Zone (SW Iberian Variscides)

    NASA Astrophysics Data System (ADS)

    Romao, Jose Manuel; Ribeiro, Antonio; Munha, Jose; Ribeiro, Luisa

    2010-05-01

    basement nappe is considerable, at least 5 to 10 km, considering the presence of mafic granulites included in intermediate granulites, both retrograded into the amphibolite facies, in the SW Bioucas and in the NE Olalhas klippe, resting on top of the lower-grade poly-metamorphic Cadomian assemblages. Geological data summarized above confirm the presence of Cadomian basement nappes that were reactivated under a thick-skinned thrust regime during the Variscan cycle; therefore, implying a poly-orogenic evolution for the studied tectonic units. TBCSZ represents a Cadomian suture that was initially reactivated during Lower Paleozoic intercontinental rifting, later evolving to transpressive intra-plate flower structure during the Upper Paleozoic Variscan convergence phase. It is concluded that thick-skinned tectonic regime by Variscan reactivation of Cadomian basement is a major element in the geodynamic evolution in the internal zones of SW European Variscides and of the Variscan Orogen in general terms.

  19. Thermal history of crystalline nappes of the Maria fold and thrust belt, west central Arizona

    SciTech Connect

    Knapp, J.H. ); Heizler, M.T. )

    1990-11-10

    The thermal history of the crust in west central Arizona, as documented by {sup 40}Ar/{sup 39}Ar step-heating analysis of mineral suites from crystalline nappes of the Maria fold and thrust belt, is characterized by three distinct stages for Late Cretaceous and Tertiary time. Regional heating of the crust occurred during basement-involved folding and thrust faulting in middle Late Cretaceous time and represents the earliest phase recorded by the {sup 40}/{sup 39}Ar data. The second stage was dominated by uplift and slow cooling (5-10C/m.y.) of the crust throughout latest Cretaceous and early Tertiary time. Tectonic denudation in late Oligocene to early Miocene time resulted in rapid uplift and cooling of midcrustal rocks in the footwall of the Whipple-Buckskin-Rawhide detachment system, marking the final thermal signature in the region. Partially outgassed hornblende in the northern Granite Wash Mountains reflects temperatures of {approximately}450C, whereas complete resetting of hornblende at Mesquite Mountain suggests that this area attained temperatures in excess of 500C. In contrast, data from the northern Plomosa Mountains indicate that this area did not attain temperatures sufficient to completely degas biotite or K-feldspar during Late Cretaceous time. Either (1) lower plate rocks were still sufficiently hot following Late Cretaceous heating that argon clocks were set simply due to rapid cooling or (2) the area experienced a renewed thermal input associated with extension, causing argon loss from previously cool rocks. Based on consideration of diffusion domain behavior in K-feldspars, the authors infer that a renewed thermal pulse was associated with the early stages of extension and was related to the cause for crustal weakening.

  20. Rechargeable lithium battery technology - A survey

    NASA Technical Reports Server (NTRS)

    Halpert, Gerald; Surampudi, Subbarao

    1990-01-01

    The technology of the rechargeable lithium battery is discussed with special attention given to the types of rechargeable lithium cells and to their expected performance and advantages. Consideration is also given to the organic-electrolyte and polymeric-electrolyte cells and to molten salt lithium cells, as well as to technical issues, such as the cycle life, charge control, rate capability, cell size, and safety. The role of the rechargeable lithium cell in future NASA applications is discussed.

  1. Ground-Water Recharge in Minnesota

    USGS Publications Warehouse

    Delin, G.N.; Falteisek, J.D.

    2007-01-01

    'Ground-water recharge' broadly describes the addition of water to the ground-water system. Most water recharging the ground-water system moves relatively rapidly to surface-water bodies and sustains streamflow, lake levels, and wetlands. Over the long term, recharge is generally balanced by discharge to surface waters, to plants, and to deeper parts of the ground-water system. However, this balance can be altered locally as a result of pumping, impervious surfaces, land use, or climate changes that could result in increased or decreased recharge. * Recharge rates to unconfined aquifers in Minnesota typically are about 20-25 percent of precipitation. * Ground-water recharge is least (0-2 inches per year) in the western and northwestern parts of the State and increases to greater than 6 inches per year in the central and eastern parts of the State. * Water-level measurement frequency is important in estimating recharge. Measurements made less frequently than about once per week resulted in as much as a 48 percent underestimation of recharge compared with estimates based on an hourly measurement frequency. * High-quality, long-term, continuous hydrologic and climatic data are important in estimating recharge rates.

  2. Imprint of foreland structure on the deformation of a thrust sheet: The Plio-Pleistocene Gela Nappe (southern Sicily, Italy)

    NASA Astrophysics Data System (ADS)

    Ghisetti, Francesca C.; Gorman, Andrew R.; Grasso, Mario; Vezzani, Livio

    2009-08-01

    In Sicily, the progressive imbrication of the Apenninic thrust belt above the Pelagian-African Foreland is traced by the southward migration of marine basins that were progressively shortened during the late Miocene-Pleistocene. The outermost and youngest thrust sheet (Gela Nappe) displays a peculiar shortening, with Messinian to early Pliocene E-W folds refolded in the late Pliocene-early Pleistocene by approximately N-S folds (subparallel to the transport direction of the thrust sheets). This structural interference is documented in south Sicily within localized belts of refolding spaced ˜5-8 km apart. The significance of this fold interference pattern is highlighted by our analysis of the offshore seismic reflection line M23A (CROP Mare Project) that intersects the Gela Nappe along a trace suborthogonal to the thrust transport direction. Migration and depth conversion of the line reveal multiple imbrications and draping of the allochthonous units above structural highs of the foreland, delimited by inherited N-S faults. The largest faults bound mid-late Miocene extensional basins but were reactivated in compression during the late Pliocene-early Pleistocene, causing (1) superposed folding along discordant N-S structural trends, (2) compressional extrusion of the whole wedge of the Gela Nappe, and (3) offset of its sole thrust. The reactivation of faults subparallel to the transport direction accommodates differential flexure of the rigid foreland beneath the Apenninic wedge, and these late stage deformations in the foreland are responsible for the superposition of E-W finite shortening onto N-S shortening.

  3. Paired stable isotopes (O, C) and clumped isotope thermometry of magnesite and silica veins in the New Caledonia Peridotite Nappe

    NASA Astrophysics Data System (ADS)

    Quesnel, Benoît; Boulvais, Philippe; Gautier, Pierre; Cathelineau, Michel; John, Cédric M.; Dierick, Malorie; Agrinier, Pierre; Drouillet, Maxime

    2016-06-01

    The stable isotope compositions of veins provide information on the conditions of fluid-rock interaction and on the origin of fluids and temperatures. In New Caledonia, magnesite and silica veins occur throughout the Peridotite Nappe. In this work, we present stable isotope and clumped isotope data in order to constrain the conditions of fluid circulation and the relationship between fluid circulation and nickel ore-forming laterization focusing on the Koniambo Massif. For magnesite veins occurring at the base of the nappe, the high δ18O values between 27.8‰ and 29.5‰ attest to a low temperature formation. Clumped isotope analyses on magnesite give temperatures between 26 °C and 42 °C that are consistent with amorphous silica-magnesite oxygen isotope equilibrium. The meteoric origin of the fluid is indicated by calculated δ18Owater values between -3.4‰ to +1.5‰. Amorphous silica associated with magnesite or occurring in the coarse saprolite level displays a narrow range of δ18O values between 29.7‰ and 35.3‰. For quartz veins occurring at the top of the bedrock and at the saprolite level, commonly in association with Ni-talc-like minerals, the δ18O values are lower, between 21.8‰ and 29.0‰ and suggest low-temperature hydrothermal conditions (∼40-95 °C). Thermal equilibration of the fluid along the geothermic gradient before upward flow through the nappe and/or influence of exothermic reactions of serpentinization could be the source(s) of heat needed to form quartz veins under such conditions.

  4. Hot granulite nappes — Tectonic styles and thermal evolution of the Proterozoic granulite belts in East Africa

    NASA Astrophysics Data System (ADS)

    Fritz, Harald; Tenczer, Veronika; Hauzenberger, Christoph; Wallbrecher, Eckart; Muhongo, Sospeter

    2009-11-01

    A section through the Neoproterozoic Mozambique Belt of Tanzania exposes western foreland (Archaean Tanzania Craton and Palaeoproterozoic Usagaran Belt), marginal (Western Granulites) and eastern, internal (Eastern Granulites) portions of the orogen. The assembly of granulite nappes at ca. 620 Ma displays westward emplacement along an eastward deepening basal decollement and forward propagation of thrusts, climbing from the deep crust to the surface. This goes along with eastward increase of syntectonic temperatures, derived from prevalent deformation mechanisms, and eastward decrease of the kinematic vorticity number. Distinctly different pressure - temperature paths with a branch of isothermal decompression (ITD) in Western Granulites and isobaric cooling (IBC) in Eastern Granulites reflect residence times of rocks within lower crustal levels. Western Granulites, exhumed rapidly at the orogen margin, display ITD and non-coaxial fabrics. Eastern Granulites in the internal orogen portions escaped from rapid exhumation and show IBC and co-axial flow fabrics. The vertical variation of structural elements, i.e. basement — cover relations within the Eastern Granulites, shows decoupling between lower and middle crust with horizontal west — east stretching in the basement and horizontal west — east shortening in the cover. A model of hot fold nappes [Beaumont, C., Nguyen, M.H., Jamieson, R.A., Ellis, S., 2006. Crustal flow modes in large hot orogens. In: Law, R.D., Searle, M.P., Godin, L., (eds). Channel Flow, Ductile Extrusion and Exhumation in Continental Collision Zones. Geological Society, London, Special Publications. vol. 268, 91-145] is adopted to explain flow diversity in the deep crust. The lower crust represented by Eastern Granulite basement flowed coaxially outwards (westward) in response to thickened crust and elevated gravitational forces, supported by a melt-weakened, viscous channel at the crustal base. Horizontal flow with rates faster than thermal

  5. Progressive deformation structures associated with ductile thrusts in the Moine Nappe, Sutherland, N. Scotland

    NASA Astrophysics Data System (ADS)

    Holdsworth, Robert E.

    In the deeper parts of mountain belts, polyphase structural sequences observed at outcrop-scale can arise due either to overprinting of regionally distinct deformation phases (e.g. reworking, changes in orogenic boundary conditions), or to localized controls that bring about transient changes in the patterns of ductile flow. These are unlikely to be mutually exclusive processes, and examples from Scotland demonstrate that, once regionally separate events are delimited using radiometric evidence, it is possible to isolate complex deformation sequences arising due to local controls. In the western Moine Nappe of Sutherland, the dominant structures were formed during Caledonian ductile thrusting towards the WNW, whilst earlier (?Precambrian) phases are relatively minor in importance. Two groups of Caledonian folds and fabrics are recognized in many exposures: main phase ( D2) structures which are broadly contemporaneous with ductile thrust fabrics, and later secondary phase ( F3) folds. The latter can be divided into two geometric groups: sheath-fold types which formed initially as WNW-overturned buckles subsequently modified by ductile shearing; and asymmetric types, which are commonly open folds apparently formed with axes close or sub-parallel to the thrust transport direction. Secondary structures show a close spatial association with high strain zones along ductile thrusts, and can be shown to have formed during the later stages of thrusting in certain critical exposures. I propose that they may form due to strain perturbations resulting from variations in the relative rates of ductile flow within the mylonites. Where differential shearing occurs due to flow-normal perturbations, wrench-related asymmetric fold types may form. In contrast, secondary sheath-fold structures may result from localized compression phases caused by flow-parallel perturbations. Local flow-perturbation models may be appropriate in situations where the distribution of later structures is

  6. Reflections on Dry-Zone Recharge

    NASA Astrophysics Data System (ADS)

    Gee, G. W.

    2005-05-01

    Quantifying recharge in regions of low precipitation remains a challenging task. The design of permanent nuclear-waste isolation at Yucca Mountain, Nevada, the design of arid-site landfill covers and the pumping of groundwater in desert cities, like Las Vegas, are examples where accurate recharge estimates are needed because they affect billion-dollar decisions. Recharge cannot be measured directly and must rely on estimation methods of various kinds including chemical tracers, thermal profiling, lysimetry, and water-balance modeling. Chemical methods, like chloride-mass-balance can significantly underestimate actual recharge rates and water-balance models are generally limited by large uncertainties. Studies at the U. S. Department of Energy's Hanford Site in Washington State, USA illustrate how estimates of recharge rates have changed over time and how these estimates can affect waste management decisions. Lysimetry has provided reliable estimates of recharge for a wide range of surface condittions. Lysimetric observations of reduced recharge, resulting from advective drying of coarse rock piles, suggest a way to avoid costly recharge protection using titanium shields at Yucca Mountain. The Pacific Northwest National Laboratory is funded by the U. S. Department of Energy under contract DE-AC05-76-RL01830.

  7. Recharge at the Hanford Site: Status report

    SciTech Connect

    Gee, G.W.

    1987-11-01

    A variety of field programs designed to evaluate recharge and other water balance components including precipitation, infiltration, evaporation, and water storage changes, have been carried out at the Hanford Site since 1970. Data from these programs have indicated that a wide range of recharge rates can occur depending upon specific site conditions. Present evidence suggests that minimum recharge occurs where soils are fine-textured and surfaces are vegetated with deep-rooted plants. Maximum recharge occurs where coarse soils or gravels exist at the surface and soils are kept bare. Recharge can occur in areas where shallow-rooted plants dominate the surface, particularly where soils are coarse-textured. Recharge estimates have been made for the site using simulation models. A US Geological Survey model that attempts to account for climate variability, soil storage parameters, and plant factors has calculated recharge values ranging from near zero to an average of about 1 cm/yr for the Hanford Site. UNSAT-H, a deterministic model developed for the site, appears to be the best code available for estimating recharge on a site-specific basis. Appendix I contains precipitation data from January 1979 to June 1987. 42 refs., 11 figs., 11 tabs.

  8. Rechargeable lithium-ion cell

    DOEpatents

    Bechtold, Dieter; Bartke, Dietrich; Kramer, Peter; Kretzschmar, Reiner; Vollbert, Jurgen

    1999-01-01

    The invention relates to a rechargeable lithium-ion cell, a method for its manufacture, and its application. The cell is distinguished by the fact that it has a metallic housing (21) which is electrically insulated internally by two half shells (15), which cover electrode plates (8) and main output tabs (7) and are composed of a non-conductive material, where the metallic housing is electrically insulated externally by means of an insulation coating. The cell also has a bursting membrane (4) which, in its normal position, is located above the electrolyte level of the cell (1). In addition, the cell has a twisting protection (6) which extends over the entire surface of the cover (2) and provides centering and assembly functions for the electrode package, which comprises the electrode plates (8).

  9. Recharge in semiarid mountain environments

    SciTech Connect

    Gross, G.W.

    1982-06-01

    A systematic investigation of tritium activity in precipitation, surface water, springs, and ground water of the Roswell artesian basin in New Mexico, has been supplemented by hydrogeologic reconnaissance of spring systems; by various statistical correlations and spectral analysis of stream flow and water level records of observation wells; by spring discharge measurements; by stable isotope determinations (oxygen 18 and deuterium); and by numerical modeling of part of the basin. Two recharge contributions to the Principal or Carbonate Aquifer have been distinguished principally on the basis of their tritium label and aquifer response characteristics. Almost all basin waters (including deep ground water) fall close to the meteoric line of hydrogen/oxygen isotope composition, and this rules out a juvenile origin or appreciable bedrock interaction.

  10. Lithium ion rechargeable systems studies

    SciTech Connect

    Levy, S.C.; Lasasse, R.R.; Cygan, R.T.; Voigt, J.A.

    1995-02-01

    Lithium ion systems, although relatively new, have attracted much interest worldwide. Their high energy density, long cycle life and relative safety, compared with metallic lithium rechargeable systems, make them prime candidates for powering portable electronic equipment. Although lithium ion cells are presently used in a few consumer devices, e.g., portable phones, camcorders, and laptop computers, there is room for considerable improvement in their performance. Specific areas that need to be addressed include: (1) carbon anode--increase reversible capacity, and minimize passivation; (2) cathode--extend cycle life, improve rate capability, and increase capacity. There are several programs ongoing at Sandia National Laboratories which are investigating means of achieving the stated objectives in these specific areas. This paper will review these programs.

  11. Rechargeable lead-acid batteries.

    PubMed

    1990-09-01

    Batteries used in medical equipment, like their counterparts in consumer products, attract little attention until they fail to function effectively. In some applications, such as in emergency medical devices, battery failure can have fatal consequences. While modern batteries are usually quite reliable, ECRI has received 53 written problem reports and countless verbal reports or questions related to battery problems in hospitals during the past five years. This large number of reports is due, at least in part, to the enormous quality of batteries used to operate or provide backup power in contemporary hospital equipment. As part of an ongoing evaluation of rehabilitation assistive equipment, ECRI has been studying the performance of 12 V rechargeable deep-cycle lead-acid batteries used in powered wheelchairs. During the course of this evaluation, it has become apparent that many professionals, both clinical and industrial, regard batteries as "black box" devices and know little about proper care and maintenance--and even less about battery selection and purchase. Because equipment performance and reliability can be strongly influenced by different battery models, an understanding of battery characteristics and how they affect performance is essential when selecting and purchasing batteries. The types of rechargeable batteries used most commonly in hospitals are lead-acid and nickel-cadmium (nicad), which we compare below; however, the guidance we provide in this article focuses on lead-acid batteries. While the examples given are for high-capacity 12 V deep-cycle batteries, similar analyses can be applied to smaller lead-acid batteries of different voltages.

  12. A new restoration of the NFP20-East cross section and possible tectonic overpressure in the Penninic Adula Nappe (Central Alps)

    NASA Astrophysics Data System (ADS)

    Pleuger, J.; Podladchikov, Y.

    2012-04-01

    The Adula Nappe in the eastern Central Alps is one of the four units in the Alps from which ultrahigh-pressure rocks have been reported. Several very different models for its tectonic history have been published but none of these models is fully satisfactory. In the models of Schmid et al. (1996) and Engi et al. (2001), the main mechanism of exhumation is assumed to be extrusion. The extrusion models require top-to-the-hinterland, i.e. top-to-the-south faulting in the hanging wall of the exhuming nappe for which there is no evidence. Froitzheim et al. (2003) proposed a scenario with two different subduction zones, an internal one in which the South Penninic and Briançonnais domains were subducted, and an external one in which the North Penninc domain and the European margin, including the Adula nappe, were subducted. In this model, the exhumation of the Adula nappe results from the subduction of the overlying sub-Briançonnais and sub-South-Penninic mantle in the internal subduction zone. The Adula nappe would then have been exhumed from below into a top-to-the-north shear zone also affecting the overriding Briançonnais units. The main shortcoming of this model is that otherwise there is little evidence for two Alpine subduction zones. All the models cited above are based on the conversion of peak pressures obtained from geobarometry to depth by assuming lithostatic pressures. This results in a much greater burial depth of the Adula Nappe with respect to the surrounding units which poses major problems when trying to reconcile maximum burial depths of the Penninic nappes with their structural record. We performed a new restoration of the NFP20-East cross section (Schmid et al. 1996) without applying a lithostatic pressure-to-depth conversion but a purely geometrical restoration of deformation events in the Penninic nappe stack. The major constraints on these reconstructions are given by strain estimates for the major deformation phases in the units overlying the

  13. Des Moines.

    ERIC Educational Resources Information Center

    Gore, Deborah, Ed.

    1988-01-01

    This document, intended for elementary students, contains articles and activities designed to acquaint young people with the history of Des Moines, Iowa. The articles are short, and new or difficult words are highlighted and defined for young readers. "The Raccoon River Indian Agency" discusses the archeological exploration of the indian…

  14. Recharge and groundwater models: An overview

    USGS Publications Warehouse

    Sanford, W.

    2002-01-01

    Recharge is a fundamental component of groundwater systems, and in groundwater-modeling exercises recharge is either measured and specified or estimated during model calibration. The most appropriate way to represent recharge in a groundwater model depends upon both physical factors and study objectives. Where the water table is close to the land surface, as in humid climates or regions with low topographic relief, a constant-head boundary condition is used. Conversely, where the water table is relatively deep, as in drier climates or regions with high relief, a specified-flux boundary condition is used. In most modeling applications, mixed-type conditions are more effective, or a combination of the different types can be used. The relative distribution of recharge can be estimated from water-level data only, but flux observations must be incorporated in order to estimate rates of recharge. Flux measurements are based on either Darcian velocities (e.g., stream base-flow) or seepage velocities (e.g., groundwater age). In order to estimate the effective porosity independently, both types of flux measurements must be available. Recharge is often estimated more efficiently when automated inverse techniques are used. Other important applications are the delineation of areas contributing recharge to wells and the estimation of paleorecharge rates using carbon-14.

  15. A purely structural restoration of the NFP20-East cross section and potential tectonic overpressure in the Adula nappe (central Alps)

    NASA Astrophysics Data System (ADS)

    Pleuger, Jan; Podladchikov, Yuri Y.

    2014-05-01

    Common extrusion-type models for the high- to ultrahigh-pressure Adula nappe require a major normal fault along the top of this unit which is not conveyed in the structural record. This implies that such a normal fault existed but was completely erased during later deformational stages. However, there is evidence that decompression occurred during top-to-the-foreland thrusting. We performed a new, purely structural kinematic restoration of the central part of the NFP20-East cross section in order to estimate the burial depths of individual units without converting petrological pressure data into depth under the assumption that pressures were lithostatic. The results show that pressures within most of the units were close to but somewhat higher than lithostatic for several stages of the tectono-metamorphic history. Only for the maximum burial stage of the Adula nappe, we estimate local tectonic overpressures of 40 to 80% of the lithostatic pressures. Accepting such an amount of overpressure, which is moderate compared to values theoretically possible, the Adula nappe was probably not subducted to subcrustal depth. We propose that the structural record of the Penninic nappe stack is quite complete and suggest that the decay of tectonic overpressure is a feasible explanation for decompression from eclogite- to amphibolite-facies conditions during thrusting. Consequently, exhumation and convergence rates of the Eocene to Oligocene Alps may be smaller than previously assumed.

  16. Cyclic ductile and brittle deformation related to coseismic thrust fault propagation: Structural record at the base of a basement nappe (Preveli, Crete)

    NASA Astrophysics Data System (ADS)

    Nüchter, Jens-Alexander; Wassmann, Sara; Stöckhert, Bernhard

    2013-09-01

    structural record at the base of a basement nappe (Preveli nappe, Crete, Greece) thrust upon sedimentary rocks is investigated, aimed on understanding mechanisms which result in decoupling of the thrust sheet from its original substratum. We identify several superimposed deformation stages, each with characteristic structural style and indications of episodic deformation at initially high differential stress. The final stage involves formation of a matrix supported breccia transected by pseudotachylytes, comprising the lowermost 30 m of the nappe. Brecciation and pseudotachylyte formation occurred in a single event, and structures were not modified afterward. Complete induration of breccia and composition of phengite crystallized during devitrification of pseudotachylytes place the sequence of events into the middle crust. We propose a model relating episodic deformation and cyclic stress history to propagation of a thrust fault in a limited number of seismic events. Terminal brecciation and frictional fusion record passage of the fault front beneath the site of observation and decoupling of the thrust sheet. Absence of discernible further deformation is consistent with negligible basal friction during transport as a nappe. Brecciation and pseudotachylyte formation mark the switch from a history of repeated coseismic loading and postseismic stress relaxation in the plastosphere, driven by seismic events on the approaching thrust fault, to passive transport with deformation localized in a weak thrust plane. For a sequence of superimposed ductile to brittle structures, our model provides an alternative to progressive cooling and exhumation concomitant with deformation over millions of years.

  17. Groundwater recharge estimation and regionalization: the Great Bend Prairie of central Kansas and its recharge statistics

    USGS Publications Warehouse

    Sophocleous, M.

    1992-01-01

    The results of a 6 year recharge study in the Great Bend Prairie of central Kansas are statistically analyzed to regionalize the limited number of site-specific but year-round measurements. Emphasis is placed on easily measured parameters and field-measured data. The results of the statistical analysis reveal that a typical recharge event in central Kansas lasts 5-7 days, out of which 3 or 4 days are precipitation days with total precipitation of ??? 83 mm. The maximum soil-profile water storage and the maximum groundwater level resulting from the recharge event exhibit the lowest coefficients of variation, whereas the amount of recharge exhibits the highest coefficient of variation. The yearly recharge in the Great Bend Prairie ranged from 0 to 177 mm with a mean of 56 mm. Most of the recharge events occur during the months of April, May, and June, which coincide with the months of highest precipitation in the region. A multiple regression analysis revealed that the most influential variables affecting recharge are, in order of decreasing importance, total annual precipitation average maximum soil-profile water storage during the spring months, average shallowest depth to water table during the same period, and spring rainfall rate. Classification methods, whereby relatively homogeneous hydrologic-unit areas based on the four recharge-affecting variables are identified, were combined with a Geographic Information Systems (ARC/INFO) overlay analysis to derive an area-wide map of differing recharge regions. This recharge zonation is in excellent agreement with the field-site recharge values. The resulting area-weighted average annual recharge for the region is 36 mm. ?? 1992.

  18. The internal deformation of the Peridotite Nappe of New Caledonia: A structural study of serpentine-bearing faults and shear zones in the Koniambo Massif

    NASA Astrophysics Data System (ADS)

    Quesnel, Benoît; Gautier, Pierre; Cathelineau, Michel; Boulvais, Philippe; Couteau, Clément; Drouillet, Maxime

    2016-04-01

    We present a structural analysis of serpentine-bearing faults and shear zones in the Koniambo Massif, one of the klippes of the Peridotite Nappe of New Caledonia. Three structural levels are recognized. The upper level is characterized by a dense network of fractures. Antigorite and polygonal serpentine form slickenfibers along fault planes with distinct kinematics. As a result, the upper level keeps the record of at least two deformation events, the first associated with the growth of antigorite (WNW-ESE extension), the second with the growth of polygonal serpentine (NW-SE compression). The lower level coincides with the 'serpentine sole' of the nappe, which consists of massive tectonic breccias overlying a layer of mylonitic serpentinites. The sole records pervasive tangential shear with top-to-SW kinematics and represents a décollement at the base of the nappe. The intermediate level is characterized by the presence of several meters-thick conjugate shear zones accommodating NE-SW shortening. Like the sole, these shear zones involve polygonal serpentine and magnesite as the main syn-kinematic mineral phases. The shear zones likely root into the basal décollement, either along its roof or, occasionally, around its base. Compared to top-to-SW shearing along the sole, the two deformation events recorded in the upper level are older. The three structural levels correlate well with previously recognized spatial variations in the degree of serpentinization. It is therefore tempting to consider that the intensity of serpentinization played a major role in the way deformation has been distributed across the Peridotite Nappe. However, even the least altered peridotites, in the upper level, contain so much serpentine that, according to theoretical and experimental work, they should be nearly as weak as pure serpentinite. Hence, no strong vertical gradient in strength due to variations in the degree of serpentinization is expected within the exposed part of the nappe

  19. Towards a rechargeable alcohol biobattery

    NASA Astrophysics Data System (ADS)

    Addo, Paul K.; Arechederra, Robert L.; Minteer, Shelley D.

    This research focused on the transition of biofuel cell technology to rechargeable biobatteries. The bioanode compartment of the biobattery consisted of NAD-dependent alcohol dehydrogenase (ADH) immobilized into a carbon composite paste with butyl-3-methylimidazolium chloride (BMIMCl) ionic liquid serving as the electrolyte. Ferrocene was added to shuttle electrons to/from the electrode surface/current collector. The bioanode catalyzed the oxidation of ethanol to acetaldehyde in discharge mode. This bioanode was coupled to a cathode that consisted of Prussian Blue in a carbon composite paste with Nafion 212 acting as the separator between the two compartments. The biobattery can be fabricated in a charged mode with ethanol and have an open circuit potential of 0.8 V in the original state prior to charging or in the discharged mode with acetaldehyde and have an open circuit potential of 0.05 V. After charging it has an open circuit potential of 1.2 V and a maximum power density of 13.0 μW cm -3 and a maximum current density of 35.0 μA cm -3, respectively. The stability and efficiency of the biobattery were studied by cycling continuously at a discharging current of 0.4 mA and the results obtained showed reasonable stability over 50 cycles. This is a new type of secondary battery inspired by the metabolic processes of the living cell, which is an effective energy conversion system.

  20. Conductivity of electrolytes for rechargeable lithium batteries

    NASA Astrophysics Data System (ADS)

    Dudley, J. T.; Wilkinson, D. P.; Thomas, G.; Levae, R.; Woo, S.

    1991-06-01

    The conductivity of 150 nonaqueous electrolytes for rechargeable Li batteries between -60 and 80 C is reported. A wide range of solvents including esters, ethers, aromatics, chlorinated solvents, etc., and mixtures thereof, were studied. Results for five electrolyte salts which have some promise for rechargeable Li cells are presented. Several of the trends in the data are discussed, and the importance of solvent viscosity in determining electrolyte conductivity is shown.

  1. Fault zone architecture of a major oblique-slip fault in the Rawil depression, Western Helvetic nappes, Switzerland

    NASA Astrophysics Data System (ADS)

    Gasser, D.; Mancktelow, N. S.

    2009-04-01

    The Helvetic nappes in the Swiss Alps form a classic fold-and-thrust belt related to overall NNW-directed transport. In western Switzerland, the plunge of nappe fold axes and the regional distribution of units define a broad depression, the Rawil depression, between the culminations of Aiguilles Rouge massif to the SW and Aar massif to the NE. A compilation of data from the literature establishes that, in addition to thrusts related to nappe stacking, the Rawil depression is cross-cut by four sets of brittle faults: (1) SW-NE striking normal faults that strike parallel to the regional fold axis trend, (2) NW-SE striking normal faults and joints that strike perpendicular to the regional fold axis trend, and (3) WNW-ESE striking normal plus dextral oblique-slip faults as well as (4) WSW-ENE striking normal plus dextral oblique-slip faults that both strike oblique to the regional fold axis trend. We studied in detail a beautifully exposed fault from set 3, the Rezli fault zone (RFZ) in the central Wildhorn nappe. The RFZ is a shallow to moderately-dipping (ca. 30-60˚) fault zone with an oblique-slip displacement vector, combining both dextral and normal components. It must have formed in approximately this orientation, because the local orientation of fold axes corresponds to the regional one, as does the generally vertical orientation of extensional joints and veins associated with the regional fault set 2. The fault zone crosscuts four different lithologies: limestone, intercalated marl and limestone, marl and sandstone, and it has a maximum horizontal dextral offset component of ~300 m and a maximum vertical normal offset component of ~200 m. Its internal architecture strongly depends on the lithology in which it developed. In the limestone, it consists of veins, stylolites, cataclasites and cemented gouge, in the intercalated marls and limestones of anastomosing shear zones, brittle fractures, veins and folds, in the marls of anastomosing shear zones, pressure

  2. Estimated recharge rates at the Hanford Site

    SciTech Connect

    Fayer, M.J.; Walters, T.B.

    1995-02-01

    The Ground-Water Surveillance Project monitors the distribution of contaminants in ground water at the Hanford Site for the U.S. Department of Energy. A subtask called {open_quotes}Water Budget at Hanford{close_quotes} was initiated in FY 1994. The objective of this subtask was to produce a defensible map of estimated recharge rates across the Hanford Site. Methods that have been used to estimate recharge rates at the Hanford Site include measurements (of drainage, water contents, and tracers) and computer modeling. For the simulations of 12 soil-vegetation combinations, the annual rates varied from 0.05 mm/yr for the Ephrata sandy loam with bunchgrass to 85.2 mm/yr for the same soil without vegetation. Water content data from the Grass Site in the 300 Area indicated that annual rates varied from 3.0 to 143.5 mm/yr during an 8-year period. The annual volume of estimated recharge was calculated to be 8.47 {times} 10{sup 9} L for the potential future Hanford Site (i.e., the portion of the current Site bounded by Highway 240 and the Columbia River). This total volume is similar to earlier estimates of natural recharge and is 2 to 10x higher than estimates of runoff and ground-water flow from higher elevations. Not only is the volume of natural recharge significant in comparison to other ground-water inputs, the distribution of estimated recharge is highly skewed to the disturbed sandy soils (i.e., the 200 Areas, where most contaminants originate). The lack of good estimates of the means and variances of the supporting data (i.e., the soil map, the vegetation/land use map, the model parameters) translates into large uncertainties in the recharge estimates. When combined, the significant quantity of estimated recharge, its high sensitivity to disturbance, and the unquantified uncertainty of the data and model parameters suggest that the defensibility of the recharge estimates should be improved.

  3. Transient, spatially varied groundwater recharge modeling

    NASA Astrophysics Data System (ADS)

    Assefa, Kibreab Amare; Woodbury, Allan D.

    2013-08-01

    The objective of this work is to integrate field data and modeling tools in producing temporally and spatially varying groundwater recharge in a pilot watershed in North Okanagan, Canada. The recharge modeling is undertaken by using the Richards equation based finite element code (HYDRUS-1D), ArcGIS™, ROSETTA, in situ observations of soil temperature and soil moisture, and a long-term gridded climate data. The public version of HYDUS-1D and another version with detailed freezing and thawing module are first used to simulate soil temperature, snow pack, and soil moisture over a one year experimental period. Statistical analysis of the results show both versions of HYDRUS-1D reproduce observed variables to the same degree. After evaluating model performance using field data and ROSETTA derived soil hydraulic parameters, the HYDRUS-1D code is coupled with ArcGIS™ to produce spatially and temporally varying recharge maps throughout the Deep Creek watershed. Temporal and spatial analysis of 25 years daily recharge results at various representative points across the study watershed reveal significant temporal and spatial variations; average recharge estimated at 77.8 ± 50.8 mm/year. Previous studies in the Okanagan Basin used Hydrologic Evaluation of Landfill Performance without any attempt of model performance evaluation, notwithstanding its inherent limitations. Thus, climate change impact results from this previous study and similar others, such as Jyrkama and Sykes (2007), need to be interpreted with caution.

  4. UHT overprint of HP rocks? A case study from the Adula nappe complex (Central Alps, N Italy)

    NASA Astrophysics Data System (ADS)

    Tumiati, Simone; Zanchetta, Stefano; Malaspina, Nadia; Poli, Stefano

    2014-05-01

    The Adula-Cima Lunga nappe complex is located on the eastern flank of the Lepontine Dome and represents the highest of the Lower Penninic units of the Central Alps. The Adula nappe largely consists of orthogneiss and paragneiss of pre-Mesozoic origin, variably retrogressed eclogites preserved as boudins within paragneiss, minor ultramafic bodies and metasedimentary rocks of presumed Mesozoic age. The higher metamorphic conditions have been estimated for the peridotite lenses in the southern part of the nappe at pressure over 3.0 GPa and temperature of 800-850°C. Garnet lherzolite bodies crop out at three localities, from west to east: Cima di Gagnone, Alpe Arami and Mt. Duria. After the partial subduction of the European distal margin beneath the Africa-Adria margin, the HP rocks were overprinted by an upper amphibolite facies metamorphism that postdates the main phase of nappe stacking. In the southern sector of the Lepontine Dome, adjacent to the Insubric Fault, metamorphic conditions promoted extensive migmatization of both metasedimentary and metagranitoid rocks. In one single outcrop, at Monte Duria, garnet lherzolites occur in m-sized boudins hosted within partly granulitized amphibole-bearing and k-feldspar gneisses that contain also some decimeter-sized boudins of both mafic and metapelitic eclogites. This rock association is in turn embedded within the migmatitic gneisses that form most of the southern sector of the Adula nappe. Petrographic and chemical analyses indicate that garnet peridotite is composed of olivine (XMg=0.88), orthopyroxene, clinopyroxene and garnet (Py68; Cr2O3 up to 1.45 wt%) with inclusions of Cr-rich spinel (up to Cr/(Al+Cr)=0.55) surrounded by kelyphitic symplectites of opx + cpx/amph + spl. These reaction produced double coronas, one composed of opx (former ol) and one composed of cpx + opx+ spl. In one kelyphite, we observed the uncommon occurrence of ZrO2 (baddeleyite) and ZrTi2O6 (srilankite). Tiny crystals of these two Zr

  5. Using groundwater levels to estimate recharge

    USGS Publications Warehouse

    Healy, R.W.; Cook, P.G.

    2002-01-01

    Accurate estimation of groundwater recharge is extremely important for proper management of groundwater systems. Many different approaches exist for estimating recharge. This paper presents a review of methods that are based on groundwater-level data. The water-table fluctuation method may be the most widely used technique for estimating recharge; it requires knowledge of specific yield and changes in water levels over time. Advantages of this approach include its simplicity and an insensitivity to the mechanism by which water moves through the unsaturated zone. Uncertainty in estimates generated by this method relate to the limited accuracy with which specific yield can be determined and to the extent to which assumptions inherent in the method are valid. Other methods that use water levels (mostly based on the Darcy equation) are also described. The theory underlying the methods is explained. Examples from the literature are used to illustrate applications of the different methods.

  6. Recharge estimation for transient ground water modeling.

    PubMed

    Jyrkama, Mikko I; Sykes, Jon F; Normani, Stefano D

    2002-01-01

    Reliable ground water models require both an accurate physical representation of the system and appropriate boundary conditions. While physical attributes are generally considered static, boundary conditions, such as ground water recharge rates, can be highly variable in both space and time. A practical methodology incorporating the hydrologic model HELP3 in conjunction with a geographic information system was developed to generate a physically based and highly detailed recharge boundary condition for ground water modeling. The approach uses daily precipitation and temperature records in addition to land use/land cover and soils data. The importance of the method in transient ground water modeling is demonstrated by applying it to a MODFLOW modeling study in New Jersey. In addition to improved model calibration, the results from the study clearly indicate the importance of using a physically based and highly detailed recharge boundary condition in ground water quality modeling, where the detailed knowledge of the evolution of the ground water flowpaths is imperative. The simulated water table is within 0.5 m of the observed values using the method, while the water levels can differ by as much as 2 m using uniform recharge conditions. The results also show that the combination of temperature and precipitation plays an important role in the amount and timing of recharge in cooler climates. A sensitivity analysis further reveals that increasing the leaf area index, the evaporative zone depth, or the curve number in the model will result in decreased recharge rates over time, with the curve number having the greatest impact.

  7. Groundwater recharge from point to catchment scale

    NASA Astrophysics Data System (ADS)

    Leterme, Bertrand; Di Ciacca, Antoine; Laloy, Eric; Jacques, Diederik

    2016-04-01

    Accurate estimation of groundwater recharge is a challenging task as only a few devices (if any) can measure it directly. In this study, we discuss how groundwater recharge can be calculated at different temporal and spatial scales in the Kleine Nete catchment (Belgium). A small monitoring network is being installed, that is aimed to monitor the changes in dominant processes and to address data availability as one goes from the point to the catchment scale. At the point scale, groundwater recharge is estimated using inversion of soil moisture and/or water potential data and stable isotope concentrations (Koeniger et al. 2015). At the plot scale, it is proposed to monitor the discharge of a small drainage ditch in order to calculate the field groundwater recharge. Electrical conductivity measurements are necessary to separate shallow from deeper groundwater contribution to the ditch discharge (see Di Ciacca et al. poster in session HS8.3.4). At this scale, two or three-dimensional process-based vadose zone models will be used to model subsurface flow. At the catchment scale though, using a mechanistic, process-based model to estimate groundwater recharge is debatable (because of, e.g., the presence of numerous drainage ditches, mixed land use pixels, etc.). We therefore investigate to which extent various types of surrogate models can be used to make the necessary upscaling from the plot scale to the scale of the whole Kleine Nete catchment. Ref. Koeniger P, Gaj M, Beyer M, Himmelsbach T (2015) Review on soil water isotope based groundwater recharge estimations. Hydrological Processes, DOI: 10.1002/hyp.10775

  8. Experimental studies in natural groundwater-recharge dynamics: The analysis of observed recharge events

    USGS Publications Warehouse

    Sophocleous, M.; Perry, C.A.

    1985-01-01

    The amounts and time distribution of groundwater recharge from precipitation over an approximately 19-month period were investigated at two instrumented sites in south-central Kansas. Precipitation and evapotranspiration sequences, soil-moisture profiles and storage changes, water fluxes in the unsaturated zone and hydraulic gradients in the saturated zone at various depths, soil temperatures, water-table hydrographs, and water-level changes in nearby wells clearly depict the recharge process. Antecedent moisture conditions and the thickness and nature of the unsaturated zone were found to be the major factors affecting recharge. Although the two instrumented sites are located in sand-dune environments in areas characterized by shallow water table and subhumid continental climate, a significant difference was observed in the estimated effective recharge. The estimates ranged from less than 2.5 to approximately 154 mm at the two sites from February to June 1983. The main reasons for this large difference in recharge estimates were the greater thickness of the unsaturated zone and the lower moisture content in that zone resulting from lower precipitation and higher potential evapotranspiration for one of the sites. Effective recharge took place only during late winter and spring. No summer or fall recharge was observed at either site during the observation period of this study. ?? 1985.

  9. The recharge process in alluvial strip aquifers in arid Namibia and implication for artificial recharge

    NASA Astrophysics Data System (ADS)

    Sarma, Diganta; Xu, Yongxin

    2016-10-01

    Alluvial strip aquifers associated with ephemeral rivers are important groundwater supply sources that sustain numerous settlements and ecological systems in arid Namibia. More than 70 % of the population in the nation's western and southern regions depend on alluvial aquifers associated with ephemeral rivers. Under natural conditions, recharge occurs through infiltration during flood events. Due to the characteristic spatial and temporal variability of rainfall in arid regions, recharge is irregular making the aquifers challenging to manage sustainably and they are often overexploited. This condition is likely to become more acute with increasing water demand and climate change, and artificial recharge has been projected as the apparent means of increasing reliability of supply. The article explores, through a case study and numerical simulation, the processes controlling infiltration, significance of surface water and groundwater losses, and possible artificial recharge options. It is concluded that recharge processes in arid alluvial aquifers differ significantly from those processes in subhumid systems and viability of artificial recharge requires assessment through an understanding of the natural recharge process and losses from the aquifer. It is also established that in arid-region catchments, infiltration through the streambed occurs at rates dependent on factors such as antecedent conditions, flow rate, flow duration, channel morphology, and sediment texture and composition. The study provides an important reference for sustainable management of alluvial aquifer systems in similar regions.

  10. Improved Separators For Rechargeable Lithium Cells

    NASA Technical Reports Server (NTRS)

    Shen, David; Surampudi, Subbarao; Huang, Chen-Kuo; Halpert, Gerald

    1994-01-01

    Improved pairs of separators proposed for use in rechargeable lithium cells operating at ambient temperature. Block growth of lithium dendrites and help prevent short circuits. Each cell contains one separator made of microporous polypropylene placed next to anode, and one separator made of microporous polytetrafluoroethylene (PTFE) next to cathode. Separators increase cycle lives of secondary lithium cells. Cells to which concept applicable those of Li/TiS(2), Li/NbSe(3), Li/CoO(2), Li/MoS(2), Li/VO(x), and Li/MnO(2) chemical systems. Advantageous in spacecraft, military, communications, automotive, and other applications in which high energy density and rechargeability needed.

  11. Characterization of basement highs in hyper-extended rift systems: examples from the Err nappe, SE Switzerland.

    NASA Astrophysics Data System (ADS)

    Epin, Marie-Eva; Manatschal, Gianreto; Haupert, Isabelle; Decarlis, Alessandro

    2015-04-01

    Despite of the fact that many studies investigated magma-poor rifted margins, there are still open questions that are related to the nature of basement highs and the timing and processes related to their formation. While these questions are difficult to answer at present-day margins due to the lack of drill hole data, field analogues provide important insights and enable to find some answers to these questions. This is particularly true for the Err nappe in southeastern Switzerland, which is one of the world's few exposed and preserved rift-related hyper-extended domains. This nappe preserves a rift related extensional detachment system that is exposed over more than 200km2, characterized by distinctive black gouges and green cataclasites and preserving the relation to its hanging wall and footwall rocks and the pre-, syn-, and post-tectonic sediments. The aim of our study was to investigate the 3D architecture of the detachment system based on detailed mapping of this structure north and south of the Julier valley between Bivio and San Moritz in Central Grisons, SE Switzerland. Our results show the lateral variation of the morphology of the major detachment fault and its relation to extensional allochthons and the pre-, syn- and post-tectonic sediments. The main observation is that the architecture of the detachment system changes over very short distance across the Julier valley. While in the north the detachment is overlain by an allochthonous block (e.g. the Bardella block), to the south this block disappears and the detachment fault is exhumed at the seafloor. The mapping of the syn-tectonic sediments show that they are thick in the north and get thinner to the south where they are locally absent and the post-rift sediments directly overlie the detachment system. Furthermore the syn-tectonic sediments are locally characterized by basement clasts. These relationships suggest a rapid change from a domain where the detachment is overlain by allochthons and thick

  12. Karst and artificial recharge: Theoretical and practical problems. A preliminary approach to artificial recharge assessment

    NASA Astrophysics Data System (ADS)

    Daher, Walid; Pistre, Séverin; Kneppers, Angeline; Bakalowicz, Michel; Najem, Wajdi

    2011-10-01

    SummaryManaged Aquifer Recharge (MAR) is an emerging sustainable technique that has already generated successful results and is expected to solve many water resource problems, especially in semi-arid and arid zones. It is of great interest for karst aquifers that currently supply 20-25% of the world's potable water, particularly in Mediterranean countries. However, the high heterogeneity in karst aquifers is too complex to be able to locate and describe them simply via field observations. Hence, as compared to projects in porous media, MAR is still marginal in karst aquifers. Accordingly, the present work presents a conceptual methodology for Aquifer Rechargeability Assessment in Karst - referred to as ARAK. The methodology was developed noting that artificial recharge in karst aquifers is considered an improbable challenge to solve since karst conduits may drain off recharge water without any significant storage, or recharge water may not be able to infiltrate. The aim of the ARAK method is to determine the ability of a given karst aquifer to be artificially recharged and managed, and the best sites for implementing artificial recharge from the surface. ARAK is based on multi-criteria indexation analysis modeled on karst vulnerability assessment methods. ARAK depends on four independent criteria, i.e. Epikarst, Rock, Infiltration and Karst. After dividing the karst domain into grids, these criteria are indexed using geological and topographic maps refined by field observations. ARAK applies a linear formula that computes the intrinsic rechargeability index based on the indexed map for every criterion, coupled with its attributed weighting rate. This index indicates the aptitude for recharging a given karst aquifer, as determined by studying its probability first on a regional scale for the whole karst aquifer, and then by characterizing the most favorable sites. Subsequently, for the selected sites, a technical and economic feasibility factor is applied, weighted

  13. REFLEAK: NIST Leak/Recharge Simulation Program for Refrigerant Mixtures

    National Institute of Standards and Technology Data Gateway

    SRD 73 NIST REFLEAK: NIST Leak/Recharge Simulation Program for Refrigerant Mixtures (PC database for purchase)   REFLEAK estimates composition changes of zeotropic mixtures in leak and recharge processes.

  14. Characteristics of groundwater recharge on the North China Plain.

    PubMed

    Tan, Xiu-Cui; Wu, Jing-Wei; Cai, Shu-Ying; Yang, Jin-Zhong

    2014-01-01

    Groundwater recharge is an important component of the groundwater system. On the North China Plain (NCP), groundwater is the main water supply. Because of large-scale overexploitation, the water table has declined, which has produced severe adverse effects on the environment and ecosystem. In this article, tracer experiment and watershed model were used to calculate and analyze NCP groundwater recharge. In the tracer experiment, average recharge was 108 mm/year and recharge coefficient 0.16. With its improved irrigation, vegetation coverage and evapotranspiration modules, the INFIL3.0 model was used for calculation of groundwater recharge. Regional modeling results showed an average recharge of 102 mm/year and recharge coefficient 0.14, for 2001-2009. These values are very similar to those from the field tracer experiment. Influences in the two methods were analyzed. The results can provide an important reference for NCP groundwater recharge.

  15. Nappes, tectonics of oblique plate convergence, and metamorphic evolution related to 140 million years of continuous subduction, Franciscan Complex, California

    SciTech Connect

    Wakabayashi, J. )

    1992-01-01

    This paper presents a new synthesis of Franciscan Complex tectonics, with the emphasis on the pre-San Andreas fault history of these rocks. Field relations suggest that the Franciscan is characterized by nappe structures that formed during sequential accretion at the trench. The presence of these structures along with other field relations, including the lack of evidence for large offset of conglomerate suites, indicates that strike-slip fault systems of large displacement ({gt}500 km) did not cut the Franciscan Complex during subduction. Regional geology and comparisons to modern arc-trench systems suggest that strike-slip faulting associated with oblique subduction took place inboard (east) of the Franciscan in the vicinity of the magmatic arc. The Franciscan varies along strike, because individual accreted elements (packets of trench sediment, seamounts, etc.) did not extend the full length of the trench. Different depths of underplating, distribution of post-metamorphic faulting, and level of erosion produced the present-day surface distribution of high P/T metamorphism. Franciscan Complex tectonic history is presented in this paper.

  16. Magnetic fabric development in a highly anisotropic magnetite-bearing ductile shear zone (Seve Nappe Complex, Scandinavian Caledonides)

    NASA Astrophysics Data System (ADS)

    Kontny, A.; Engelmann, R.; Grimmer, J. C.; Greiling, R. O.; Hirt, A.

    2012-04-01

    Magnetite-bearing mylonitic garnet-micaschists close to the major suture between the Baltica and Iapetus terranes (Seve Nappe Complex, Scandinavian Caledonides) show very high anisotropy of magnetic susceptibility (AMS) with corrected degree of anisotropy ( P') up to 4.8. Three different magnetic fabric types can be distinguished. They correspond to protomylonite (type I, P' < 2), mylonite (type II, 2 < P' < 3), and ultramylonite (type III, P' > 3), respectively. The orientation of the ellipsoid axes from all applied magnetic fabric methods in this study is similar with shallow dips of the metamorphic foliation toward WSW and subhorizontal, mostly NW-SE trending mineral lineation. Differences between subfabrics were minimized under high shear strain as all markers tend to align parallel with the shear plane. The very high anisotropies and mostly oblate ellipsoid shapes of type III correlate with high magnetic susceptibility ( k mean up to 55 × 10-3 SI units) and are related to the concentration of magnetite aggregates with shape-preferred orientation. They show a distinct field dependence of magnetic susceptibility of up to 10% in the k max-direction. We attribute this field dependence to a "memory" of high strains in the domain walls of the crystals acquired during synkinematic magnetite growth during shear zone fabric development at temperatures of 550-570°C.

  17. Rechargeable solid polymer electrolyte battery cell

    DOEpatents

    Skotheim, Terji

    1985-01-01

    A rechargeable battery cell comprising first and second electrodes sandwiching a solid polymer electrolyte comprising a layer of a polymer blend of a highly conductive polymer and a solid polymer electrolyte adjacent said polymer blend and a layer of dry solid polymer electrolyte adjacent said layer of polymer blend and said second electrode.

  18. Application potential of rechargeable lithium batteries

    SciTech Connect

    Hunger, H.F.; Bramhall, P.J.

    1983-10-01

    Rechargeable lithium cells with Cr /SUB 0.5/ V/sub 0/ /sub 5/S/sub 2/ and MoO/sub 3/ cathodes were investigated in the temperature range of -30/sup 0/C to +25/sup 0/C. The electrolyte was 1.5M LiAsF/sub 6/ in 2-methyl tetrahydrofuran with tetrahydrofuran (50:50 V percent). Current densities and capacities as a function of temperature, cathode utilization efficiencies versus cycle life, and shelf lives were determined. The state of charge could be related to open circuit voltages after partial discharge. The potential of the system for communication applications is discussed. Recent advances in rechargeable lithium batteries were mainly due to the discovery of stable, cyclic ether electrolyte solvents (1) and to the use of rechargeable cathode materials (2). The practical usefulness of rechargeable lithium cells with Cr /SUB 0.5/ V /SUB 0.5/ S/sub 2/ and MoO/sub 3/ cathodes was investigated in the temperature range of -30/sup 0/C to +25/sup 0/C. The electrolyte was mainly 1.5M LiAsF/sub 6/ in 2-methyl tetrahydrofuran with tetrahydrofuran (50:50 V percent). The two cathode materials were chosen because Cr /SUB 0.5/ V /SUB 0.5/ S/sub 2/ resembles TiS/sub 2/ in capacity and cycling behavior and MoO/sub 3/ is a low cost cathode material of interest.

  19. Anodes for Rechargeable Lithium-Sulfur Batteries

    SciTech Connect

    Cao, Ruiguo; Xu, Wu; Lu, Dongping; Xiao, Jie; Zhang, Jiguang

    2015-04-10

    In this work, we will review the recent developments on the protection of Li metal anode in Li-S batteries. Various strategies used to minimize the corrosion of Li anode and reducing its impedance increase will be analyzed. Other potential anodes used in sulfur based rechargeable batteries will also be discussed.

  20. Design considerations for rechargeable lithium batteries

    NASA Technical Reports Server (NTRS)

    Shen, D. H.; Huang, C.-K.; Davies, E.; Perrone, D.; Surampudi, S.; Halpert, Gerald

    1993-01-01

    Viewgraphs of a discussion of design considerations for rechargable lithium batteries. The objective is to determine the influence of cell design parameters on the performance of Li-TiS2 cells. Topics covered include cell baseline design and testing, cell design and testing, cell design parameters studies, and cell cycling performance.

  1. Alloys of clathrate allotropes for rechargeable batteries

    SciTech Connect

    Chan, Candace K; Miller, Michael A; Chan, Kwai S

    2014-12-09

    The present disclosure is directed at an electrode for a battery wherein the electrode comprises clathrate alloys of silicon, germanium or tin. In method form, the present disclosure is directed at methods of forming clathrate alloys of silicon, germanium or tin which methods lead to the formation of empty cage structures suitable for use as electrodes in rechargeable type batteries.

  2. Recharging Our Sense of Idealism: Concluding Thoughts

    ERIC Educational Resources Information Center

    D'Andrea, Michael; Dollarhide, Colette T.

    2011-01-01

    In this article, the authors aim to recharge one's sense of idealism. They argue that idealism is the Vitamin C that sustains one's commitment to implementing humanistic principles and social justice practices in the work of counselors and educators. The idealism that characterizes counselors and educators who are humanistic and social justice…

  3. Geochemical quantification of semiarid mountain recharge.

    PubMed

    Wahi, Arun K; Hogan, James F; Ekwurzel, Brenda; Baillie, Matthew N; Eastoe, Christopher J

    2008-01-01

    Analysis of a typical semiarid mountain system recharge (MSR) setting demonstrates that geochemical tracers help resolve the location, rate, and seasonality of recharge as well as ground water flowpaths and residence times. MSR is defined as the recharge at the mountain front that dominates many semiarid basins plus the often-overlooked recharge through the mountain block that may be a significant ground water resource; thus, geochemical measurements that integrate signals from all flowpaths are advantageous. Ground water fluxes determined from carbon-14 ((14)C) age gradients imply MSR rates between 2 x 10(6) and 9 x 10(6) m(3)/year in the Upper San Pedro Basin, Arizona, USA. This estimated range is within an order of magnitude of, but lower than, prior independent estimates. Stable isotopic signatures indicate that MSR has a 65% +/- 25% contribution from winter precipitation and a 35% +/- 25% contribution from summer precipitation. Chloride and stable isotope results confirm that transpiration is the dominant component of evapotranspiration (ET) in the basin with typical loss of more than 90% of precipitation-less runoff to ET. Such geochemical constraints can be used to further refine hydrogeologic models in similar high-elevation relief basins and can provide practical first estimates of MSR rates for basins lacking extensive prior hydrogeologic measurements.

  4. Focused Recharge in a Theoretical Raingarden

    NASA Astrophysics Data System (ADS)

    Dussaillant, A. R.; Dussaillant, A. R.; Potter, K. W.; Wu, C.

    2001-05-01

    Traditional stormwater management, which relies heavily on detention, does not mitigate groundwater depletion resulting from groundwater pumping and loss of groundwater recharge. In recent years there has been increasing interest in the use of practices, such as raingardens, that encourage infiltration of stormwater as a means of mitigating groundwater impacts. These can be particularly effective when infiltration is focused in order to maximize groundwater recharge. However, traditional hydrologic models are not well suited to describe focused infiltration. We have developed a model of focused recharge that can be applied in the design and evaluation of raingardens. The rain garden is represented by three homogeneous layers of soil. The upper layer represents the root zone. The middle layer is a high conductivity layer that provides water storage. The lower layer represents the urban soil, which may restrict water flow. To continuously simulate recharge, runoff and evapotranspiration during the wet and dry periods, a Richards equation is used to estimate soil water movement. Runoff from the garden is approximated by a weir equation, assuming a maximum ponding depth of 15 cm. Evapotranspiration is based on the Priestley & Taylor model, taking into account the partition of radiation through the plant canopy and the available soil water. A fully implicit finite difference approach is used to solve the model equation, with a modified Picard iteration for mass balancing. Results of the raingarden water budget will be presented for long-term continuous simulations.

  5. Anode for rechargeable ambient temperature lithium cells

    NASA Technical Reports Server (NTRS)

    Huang, Chen-Kuo (Inventor); Surampudi, Subbarao (Inventor); Attia, Alan I. (Inventor); Halpert, Gerald (Inventor)

    1994-01-01

    An ambient room temperature, high density, rechargeable lithium battery includes a Li(x)Mg2Si negative anode which intercalates lithium to form a single crystalline phase when x is up to 1.0 and an amorphous phase when x is from 1 to 2.0. The electrode has good reversibility and mechanical strength after cycling.

  6. Natural vs. artificial groundwater recharge, quantification through inverse modeling

    NASA Astrophysics Data System (ADS)

    Hashemi, H.; Berndtsson, R.; Kompani-Zare, M.; Persson, M.

    2012-08-01

    Estimating the change in groundwater recharge from an introduced artificial recharge system is important in order to evaluate future water availability. This paper presents an inverse modeling approach to quantify the recharge contribution from both an ephemeral river channel and an introduced artificial recharge system based on floodwater spreading in arid Iran. The study used the MODFLOW-2000 to estimate recharge for both steady and unsteady-state conditions. The model was calibrated and verified based on the observed hydraulic head in observation wells and model precision, uncertainty, and model sensitivity were analyzed in all modeling steps. The results showed that in a normal year without extreme events the floodwater spreading system is the main contributor to recharge with 80% and the ephemeral river channel with 20% of total recharge in the studied area. Uncertainty analysis revealed that the river channel recharge estimation represents relatively more uncertainty in comparison to the artificial recharge zones. The model is also less sensitive to the river channel. The results show that by expanding the artificial recharge system the recharge volume can be increased even for small flood events while the recharge through the river channel increases only for major flood events.

  7. Natural vs. artificial groundwater recharge, quantification through inverse modeling

    NASA Astrophysics Data System (ADS)

    Hashemi, H.; Berndtsson, R.; Kompani-Zare, M.; Persson, M.

    2013-02-01

    Estimating the change in groundwater recharge from an introduced artificial recharge system is important in order to evaluate future water availability. This paper presents an inverse modeling approach to quantify the recharge contribution from both an ephemeral river channel and an introduced artificial recharge system based on floodwater spreading in arid Iran. The study used the MODFLOW-2000 to estimate recharge for both steady- and unsteady-state conditions. The model was calibrated and verified based on the observed hydraulic head in observation wells and model precision, uncertainty, and model sensitivity were analyzed in all modeling steps. The results showed that in a normal year without extreme events, the floodwater spreading system is the main contributor to recharge with 80% and the ephemeral river channel with 20% of total recharge in the studied area. Uncertainty analysis revealed that the river channel recharge estimation represents relatively more uncertainty in comparison to the artificial recharge zones. The model is also less sensitive to the river channel. The results show that by expanding the artificial recharge system, the recharge volume can be increased even for small flood events, while the recharge through the river channel increases only for major flood events.

  8. Estimating recharge rates with analytic element models and parameter estimation

    USGS Publications Warehouse

    Dripps, W.R.; Hunt, R.J.; Anderson, M.P.

    2006-01-01

    Quantifying the spatial and temporal distribution of recharge is usually a prerequisite for effective ground water flow modeling. In this study, an analytic element (AE) code (GFLOW) was used with a nonlinear parameter estimation code (UCODE) to quantify the spatial and temporal distribution of recharge using measured base flows as calibration targets. The ease and flexibility of AE model construction and evaluation make this approach well suited for recharge estimation. An AE flow model of an undeveloped watershed in northern Wisconsin was optimized to match median annual base flows at four stream gages for 1996 to 2000 to demonstrate the approach. Initial optimizations that assumed a constant distributed recharge rate provided good matches (within 5%) to most of the annual base flow estimates, but discrepancies of >12% at certain gages suggested that a single value of recharge for the entire watershed is inappropriate. Subsequent optimizations that allowed for spatially distributed recharge zones based on the distribution of vegetation types improved the fit and confirmed that vegetation can influence spatial recharge variability in this watershed. Temporally, the annual recharge values varied >2.5-fold between 1996 and 2000 during which there was an observed 1.7-fold difference in annual precipitation, underscoring the influence of nonclimatic factors on interannual recharge variability for regional flow modeling. The final recharge values compared favorably with more labor-intensive field measurements of recharge and results from studies, supporting the utility of using linked AE-parameter estimation codes for recharge estimation. Copyright ?? 2005 The Author(s).

  9. Regional Analysis of Ground-Water Recharge

    USGS Publications Warehouse

    Flint, Lorraine E.; Flint, Alan L.

    2007-01-01

    A modeling analysis of runoff and ground-water recharge for the arid and semiarid southwestern United States was performed to investigate the interactions of climate and other controlling factors and to place the eight study-site investigations into a regional context. A distributed-parameter water-balance model (the Basin Characterization Model, or BCM) was used in the analysis. Data requirements of the BCM included digital representations of topography, soils, geology, and vegetation, together with monthly time-series of precipitation and air-temperature data. Time-series of potential evapotranspiration were generated by using a submodel for solar radiation, taking into account topographic shading, cloudiness, and vegetation density. Snowpack accumulation and melting were modeled using precipitation and air-temperature data. Amounts of water available for runoff and ground-water recharge were calculated on the basis of water-budget considerations by using measured- and generated-meteorologic time series together with estimates of soil-water storage and saturated hydraulic conductivity of subsoil geologic units. Calculations were made on a computational grid with a horizontal resolution of about 270 meters for the entire 1,033,840 square-kilometer study area. The modeling analysis was composed of 194 basins, including the eight basins containing ground-water recharge-site investigations. For each grid cell, the BCM computed monthly values of potential evapotranspiration, soil-water storage, in-place ground-water recharge, and runoff (potential stream flow). A fixed percentage of runoff was assumed to become recharge beneath channels operating at a finer resolution than the computational grid of the BCM. Monthly precipitation and temperature data from 1941 to 2004 were used to explore climatic variability in runoff and ground-water recharge. The selected approach provided a framework for classifying study-site basins with respect to climate and dominant recharge

  10. Automatic rainfall recharge model induction by evolutionary computational intelligence

    NASA Astrophysics Data System (ADS)

    Hong, Yoon-Seok Timothy; White, Paul A.; Scott, David M.

    2005-08-01

    Genetic programming (GP) is used to develop models of rainfall recharge from observations of rainfall recharge and rainfall, calculated potential evapotranspiration (PET) and soil profile available water (PAW) at four sites over a 4 year period in Canterbury, New Zealand. This work demonstrates that the automatic model induction method is a useful development in modeling rainfall recharge. The five best performing models evolved by genetic programming show a highly nonlinear relationship between rainfall recharge and the independent variables. These models are dominated by a positive correlation with rainfall, a negative correlation with the square of PET, and a negative correlation with PAW. The best performing GP models are more reliable than a soil water balance model at predicting rainfall recharge when rainfall recharge is observed in the late spring, summer, and early autumn periods. The ``best'' GP model provides estimates of cumulative sums of rainfall recharge that are closer than a soil water balance model to observations at all four sites.

  11. Quantifying macropore recharge: Examples from a semi-arid area

    USGS Publications Warehouse

    Wood, W.W.; Rainwater, K.A.; Thompson, D.B.

    1997-01-01

    The purpose of this paper is to illustrate the significantly increased resolution of determining macropore recharge by combining physical, chemical, and isotopic methods of analysis. Techniques for quantifying macropore recharge were developed for both small-scale (1 to 10 km2) and regional-scale areas in and semi-arid areas. The Southern High Plains region of Texas and New Mexico was used as a representative field site to test these methods. Macropore recharge in small-scale areas is considered to be the difference between total recharge through floors of topographically dosed basins and interstitial recharge through the same area. On the regional scale, macropore recharge was considered to be the difference between regional average annual recharge and interstitial recharge measured in the unsaturated zone. Stable isotopic composition of ground water and precipitation was used us an independent estimate of macropore recharge on the regional scale. Results of this analysis suggest that in the Southern High Plains recharge flux through macropores is between 60 and 80 percent of the total 11 mm/y. Between 15 and 35 percent of the recharge occurs by interstitial recharge through the basin floors. Approximately 5 percent of the total recharge occurs as either interstitial or matrix recharge between the basin floors, representing approximately 95 percent of the area. The approach is applicable to other arid and semi-arid areas that focus rainfall into depressions or valleys.The purpose of this paper is to illustrate the significantly increased resolution of determining macropore recharge by combining physical, chemical, and isotopic methods of analysis. Techniques for quantifying macropore recharge were developed for both small-scale (1 to 10 km2) and regional-scale areas in arid and semi-arid areas. The Southern High Plains region of Texas and New Mexico was used as a representative field site to test these methods. Macropore recharge in small-scale areas is considered

  12. Post-orogenic extension and metamorphic core complexes in a heterogeneous crust, the role of preexisting nappes

    NASA Astrophysics Data System (ADS)

    Huet, B.; Le Pourhiet, L.; Labrousse, L.; Burov, E. B.; Jolivet, L.

    2009-12-01

    Field observations in post-orogenic domains evidence a strong partitioning of deformation between the upper and lower crusts during the formation of metamorphic core complexes (MCCs). Furthermore, numerical models suggest that major rheological contrasts between a resistant upper crust and a low viscosity lower crust are essential for the development of these structures. As a general agreement, warm thermal profiles are therefore considered to be the main cause of the rheological stratification. This assumption is however not compatible with the limited to absent retrograde heating within some exhumed High Pressure - Low Temperature (HP-LT) metamorphic units, as is observed in the northern Cycladic MCCs in the Aegean domain. The purpose of our study is to reconsider the initial state of the crust at the onset of post-orogenic extension. We investigate, through thermo-mechanical modeling, how crustal stratification, inherited from the nappe stacking stage, influences the occurrence of MCCs in former orogens. Rocks are believed to be more mafic with depth in normal crusts. If the nappe stacking episode is taken into account, the lithological profile of the crust can be more complex with some reversed strength gradients. The history of thickening may therefore strongly influence the crustal rheological profile at the onset of extension. To test this idea, we explored the effect of three possible crustal stratifications (homogeneous, normal and reversed), as well as three thermal profiles (cold, intermediate and warm). The numerical experiments show that the degree of lateral localization and the dynamics of exhumation are strongly controlled by the crustal stratification, and, to a lesser extent, by the temperature profile. Four modes of extension are distinguished: common-type rift, wide rift, metamorphic core complex and spreading dome. Spreading dome distinguishes from metamorphic core complex by the exhumation of material along a ridge located in the center of the

  13. Assessing controls on diffuse groundwater recharge using unsaturated flow modeling

    NASA Astrophysics Data System (ADS)

    Keese, K. E.; Scanlon, B. R.; Reedy, R. C.

    2005-06-01

    Understanding climate, vegetation, and soil controls on recharge is essential for estimating potential impacts of climate variability and land use/land cover change on recharge. Recharge controls were evaluated by simulating drainage in 5-m-thick profiles using a one-dimensional (1-D) unsaturated flow code (UNSAT-H), climate data, and vegetation and soil coverages from online sources. Soil hydraulic properties were estimated from STATSGO/SSURGO soils data using pedotransfer functions. Vegetation parameters were obtained from the literature. Long-term (1961-1990) simulations were conducted for 13 county-scale regions representing arid to humid climates and different vegetation and soil types, using data for Texas. Areally averaged recharge rates are most appropriate for water resources; therefore Geographic Information Systems were used to determine spatial weighting of recharge results from 1-D models for the combination of vegetation and soils in each region. Simulated 30-year mean annual recharge in bare sand is high (51-709 mm/yr) and represents 23-60% (arid-humid) of mean annual precipitation (MAP). Adding vegetation reduced recharge by factors of 2-30 (humid-arid), and soil textural variability reduced recharge by factors of 2-11 relative to recharge in bare sand. Vegetation and soil textural variability both resulted in a large range of recharge rates within each region; however, spatially weighted, long-term recharge rates were much less variable and were positively correlated with MAP (r2 = 0.85 for vegetated sand; r2 = 0.62 for variably textured soils). The most realistic simulations included vegetation and variably textured soils, which resulted in recharge rates from 0.2 to 118 mm/yr (0.1-10% of MAP). Mean annual precipitation explains 80% of the variation in recharge and can be used to map recharge.

  14. Ductile nappe stacking and refolding in the Cycladic Blueschist Unit: insights from Sifnos Island (south Aegean Sea)

    NASA Astrophysics Data System (ADS)

    Aravadinou, Eirini; Xypolias, Paraskevas; Chatzaras, Vasileios; Iliopoulos, Ioannis; Gerogiannis, Nikolaos

    2016-10-01

    New geological and structural mapping combined with kinematic and amphibole chemistry analyses is used to investigate the deformation history of the Cycladic Blueschist Unit (CBU) on Sifnos Island (Cyclades, Aegean Sea). We concentrate on north Sifnos, an area characterized by exceptionally well-preserved eclogites and blueschists. Our data show that the early, main phase (D2) of ductile deformation in the CBU occurred synchronous with the transition from prograde to close-to-peak retrograde conditions. This deformation phase took place at middle Eocene and is related to ESE-directed thrusting that emplaced the metavolcano-sedimentary subunit over the Marble subunit. The subsequent exhumation-related (D3) deformation is characterized by gently NE-plunging folds and NE-directed contractional shear zones that formed parallel to the axial planes of folds. NE-directed shearing occurred under blueschist and transitional blueschist-/greenschist-facies conditions during late Eocene-Oligocene and caused the restacking of the early nappe pile. We suggest that a mechanism of ductile extrusion of the CBU in a tectonic setting of net compression could explain better the recorded exhumation-related deformation than a mechanism of syn- and post-orogenic extension. Our new kinematic results in combination with previous works in the Cyclades area reveal a regional scale change in tectonic transport direction from (W)NW-(E)SE at Late Cretaceous-middle Eocene to (E)NE-(W)SW at late Eocene-Oligocene times. The observed change in transport direction may be governed by the relative motion of Africa with respect to Europe during Alpine orogeny.

  15. Sedimentary evolution of the siliciclastic Aptian-Albian Massylian flysch of the Chouamat Nappe (central Rif, Morocco)

    NASA Astrophysics Data System (ADS)

    El Talibi, Hajar; Zaghloul, Mohamed Najib; Perri, Francesco; Aboumaria, Khadija; Rossi, Abdelhamid; El Moussaoui, Said

    2014-12-01

    Sandstone petrography and geochemistry (major, trace and rare earth elements) of the Aptian-Albian siliciclastic Massylian flysch from the Chouamat Nappe (central Rif Morocco) are used to highlight the chemical weathering conditions in the source area and to infer their provenance. Petrographic studies show that the studied samples are mostly quartzarenite, sublitharenite and subarkose generally composed of quartz (up to 99%), K-feldspar (less than 5%) and scarce fragments of sedimentary rocks. The samples plot in the continental block provenance field of the QtFLt diagram. Thus, the compositional maturity of analyzed sandstones is typical of cratonic environments. The sandstone samples shows high SiO2 content (up to 96%) and strong depletion in mobile components such as Na2O, CaO as well as in ferromagnesian minerals, which are mainly related to intense chemical weathering processes in the source area, as confirmed by high Chemical Index of Alteration values (mean = 79.8). Recycling is shown by the Th/Sc vs. Zr/Sc plot, where the studied sandstones fall along a trend involving zircon addition and thus sediment recycling. Several geochemical ratios, such as La/Sc, Th/Sc, Th/Co and Th/Cr, of the studied samples are similar to those of Post-Archean Australian Shales and of the Upper Continental Crust, and suggest a provenance from source area(s) mainly composed of plutonic and felsic metasedimentary and sedimentary rocks, which were most probably the basement rocks of the adjacent African plate. These source rocks are related to a large cratonic source region of Eburnean and Pan-African belts, Precambrian (?) and/or Variscan basements of the southeastern margin of the African plate.

  16. Elastic anisotropy and borehole stress estimation in the Seve Nappe Complex from the COSC-1 well, Åre, Sweden.

    NASA Astrophysics Data System (ADS)

    Wenning, Quinn; Almquist, Bjarne; Ask, Maria; Schmitt, Douglas R.; Zappone, Alba

    2015-04-01

    The Caledonian orogeny, preserved in Scandinavia and Greenland, began with the closure of the Iapetus Ocean and culminated in the collision of Baltica and Laurentia cratons during the middle Paleozoic. The COSC scientific drilling project aims at understanding the crustal structure and composition of the Scandinavian Caledonides. The first well of the dual phase drilling program, completed in Summer of 2014, drilled through ~2.5 km of the Seve Nappe Complex near the town of Åre, Sweden. Newly acquired drill core and borehole logs provide fresh core material for physical rock property measurements and in-situ stress determination. This contribution presents preliminary data on compressional and shear wave ultrasonic velocities (Vp, Vs) determined from laboratory measurements on drill cores, together with in-situ stress orientation analysis using image logs from the first borehole of the Collisional Orogeny in the Scandinavian Caledonides project (COSC-1). An hydrostatically oil pressurized apparatus is used to test the ultrasonic Vp and Vs on three orthogonally cut samples of amphibolite, calcium bearing and felsic gneiss, meta-gabbro, and mylonitic schist from drill core. We measure directional anisotropy variability for each lithology using one sample cut perpendicular to the foliation and two additional plugs cut parallel to the foliation with one parallel to the lineation and the other perpendicular. Measurements are performed using the pulse transmission technique on samples subjected to hydrostatic pressure from 1-350 MPa at dry conditions. We present preliminary results relating Vp and Vs anisotropy to geologic units and degree of deformation. Additionally, we use acoustic borehole televiewer logs to estimate the horizontal stress orientation making use of well developed techniques for observed borehole breakouts (compressive failure) and drilling induced fractures (tensile failure). Preliminary observations show that very few drilling-induced tensile

  17. Ductile nappe stacking and refolding in the Cycladic Blueschist Unit: insights from Sifnos Island (south Aegean Sea)

    NASA Astrophysics Data System (ADS)

    Aravadinou, Eirini; Xypolias, Paraskevas; Chatzaras, Vasileios; Iliopoulos, Ioannis; Gerogiannis, Nikolaos

    2015-10-01

    New geological and structural mapping combined with kinematic and amphibole chemistry analyses is used to investigate the deformation history of the Cycladic Blueschist Unit (CBU) on Sifnos Island (Cyclades, Aegean Sea). We concentrate on north Sifnos, an area characterized by exceptionally well-preserved eclogites and blueschists. Our data show that the early, main phase (D2) of ductile deformation in the CBU occurred synchronous with the transition from prograde to close-to-peak retrograde conditions. This deformation phase took place at middle Eocene and is related to ESE-directed thrusting that emplaced the metavolcano-sedimentary subunit over the Marble subunit. The subsequent exhumation-related (D3) deformation is characterized by gently NE-plunging folds and NE-directed contractional shear zones that formed parallel to the axial planes of folds. NE-directed shearing occurred under blueschist and transitional blueschist-/greenschist-facies conditions during late Eocene-Oligocene and caused the restacking of the early nappe pile. We suggest that a mechanism of ductile extrusion of the CBU in a tectonic setting of net compression could explain better the recorded exhumation-related deformation than a mechanism of syn- and post-orogenic extension. Our new kinematic results in combination with previous works in the Cyclades area reveal a regional scale change in tectonic transport direction from (W)NW-(E)SE at Late Cretaceous-middle Eocene to (E)NE-(W)SW at late Eocene-Oligocene times. The observed change in transport direction may be governed by the relative motion of Africa with respect to Europe during Alpine orogeny.

  18. Recharge and Evapotranspiration Assessment In Kalahari

    NASA Astrophysics Data System (ADS)

    Lubczynski, M.; Obakeng, O.

    2006-12-01

    Sustainability of groundwater resources in Kalahri is constrained not only by recharge to the aquifers but also by discharge from them. Natural groundwater discharge takes place in 3 different ways, as aquifer groundwater outflow, direct tree root water uptake called groundwater transpiration (Tg) and as upward vapor-liquid water movement called groundwater evaporation (Eg), the latter two called groundwater evapotranspiration (ETg). The evaluation of ETg and recharge was the main goal of this study. Due to generally large depth of groundwater table in Kalahari, >60 m, Eg was assumed as negligible component of groundwater balances while in contrast Tg has been considered significant already since 90-ties. This was because of fragments of tree roots of Boscia albitrunca and Acacia erioloba found in borehole cores at depth of >60 m. Some of those roots reach groundwater, which allow them to remain green throughout dry seasons. This study was carried out using hydrological monitoring consisting of 10 multi-sensor towers and 17 groundwater monitoring points. Soil moisture movement was investigated by profile monitoring. The deepest profile was down to 76 m depth. The soil moisture results revealed complicated pattern characterized by a combination of diffuse and preferential flow. The actual evapotranspiration was estimated by the Bowen-ratio and temperature-profile methods which provided overestimated results as compared with rainfall so the recharge could not be deduced directly. Therefore recharge was derived indirectly, through 1D lumped parameter model that used rainfall and PET as input and heads as calibration reference. That model indicated recharge 0-50 mm/yr. For understanding tree impact upon groundwater recharge, tree sap velocity was monitored for 2 years using the Granier method on 41 trees of 9 species in 8 plots of 30x30m. The estimated plot transpirations showed large spatio-temporal variability, 3-71 mm/yr and occasionally exceeded recharge. In order

  19. Nanocomposite polymer electrolyte for rechargeable magnesium batteries

    SciTech Connect

    Shao, Yuyan; Rajput, Nav Nidhi; Hu, Jian Z.; Hu, Mary Y.; Liu, Tianbiao L.; Wei, Zhehao; Gu, Meng; Deng, Xuchu; Xu, Suochang; Han, Kee Sung; Wang, Jiulin; Nie, Zimin; Li, Guosheng; Zavadil, K.; Xiao, Jie; Wang, Chong M.; Henderson, Wesley A.; Zhang, Jiguang; Wang, Yong; Mueller, Karl T.; Persson, Kristin A.; Liu, Jun

    2014-12-28

    Nanocomposite polymer electrolytes present new opportunities for rechargeable magnesium batteries. However, few polymer electrolytes have demonstrated reversible Mg deposition/dissolution and those that have still contain volatile liquids such as tetrahydrofuran (THF). In this work, we report a nanocomposite polymer electrolyte based on poly(ethylene oxide) (PEO), Mg(BH4)2 and MgO nanoparticles for rechargeable Mg batteries. Cells with this electrolyte have a high coulombic efficiency of 98% for Mg plating/stripping and a high cycling stability. Through combined experiment-modeling investigations, a correlation between improved solvation of the salt and solvent chain length, chelation and oxygen denticity is established. Following the same trend, the nanocomposite polymer electrolyte is inferred to enhance the dissociation of the salt Mg(BH4)2 and thus improve the electrochemical performance. The insights and design metrics thus obtained may be used in nanocomposite electrolytes for other multivalent systems.

  20. The rechargeable aluminum-ion battery

    SciTech Connect

    Navaneedhakrishnan, Jayaprakash; Das, Shyamal K; Archer, Lynden A.

    2011-01-01

    We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl₃ in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V₂O₅ nano-wire cathode against an aluminium metal anode. The battery delivered a discharge capacity of 305 mAh g⁻¹ in the first cycle and 273 mAh g⁻¹ after 20 cycles, with very stable electrochemical behaviour.

  1. Charge Control Investigation of Rechargeable Lithium Cells

    NASA Technical Reports Server (NTRS)

    Otzinger, B.; Somoano, R.

    1984-01-01

    An ambient temperature rechargeable Li-TiS2 cell was cycled under conditions which simulate aerospace applications. A novel charge/discharge state-of-charge control scheme was used, together with tapered current charging, to overcome deleterious effects associated with end-of-charge and end-of-discharge voltages. The study indicates that Li-TiS2 cells hold promise for eventual synchronous satellite-type applications. Problem areas associated with performance degradation and reconditioning effects are identified.

  2. Recharge monitoring in an interplaya setting

    SciTech Connect

    Scanlon, B.R.; Reedy, R.C.; Liang, J.

    1999-03-01

    The objective of this investigation is to monitor infiltration in response to precipitation events in an interplaya setting. The authors evaluated data gathered from the interplaya recharge monitoring installation at the Pantex Plant from March through December 1998. They monitored thermocouple psychrometer (TCP) instruments to measure water potential and time-domain reflectometry (TDR) probes to measure water content and bulk soil conductivity. Heat-dissipation sensor (HDS) instruments were monitored to supplement the TCP data.

  3. The rechargeable aluminum-ion battery.

    PubMed

    Jayaprakash, N; Das, S K; Archer, L A

    2011-12-21

    We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl(3) in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V(2)O(5) nano-wire cathode against an aluminium metal anode. The battery delivered a discharge capacity of 305 mAh g(-1) in the first cycle and 273 mAh g(-1) after 20 cycles, with very stable electrochemical behaviour.

  4. Inorganic rechargeable non-aqueous cell

    SciTech Connect

    Bowden, William L.; Dey, Arabinda N.

    1985-05-07

    A totally inorganic non-aqueous rechargeable cell having an alkali or alkaline earth metal anode such as of lithium, a sulfur dioxide containing electrolyte and a discharging metal halide cathode, such as of CuCl.sub.2, CuBr.sub.2 and the like with said metal halide being substantially totally insoluble in SO.sub.2 and admixed with a conductive carbon material.

  5. Solid-state rechargeable magnesium battery

    DOEpatents

    Shao, Yuyan; Liu, Jun; Liu, Tianbiao; Li, Guosheng

    2016-09-06

    Embodiments of a solid-state electrolyte comprising magnesium borohydride, polyethylene oxide, and optionally a Group IIA or transition metal oxide are disclosed. The solid-state electrolyte may be a thin film comprising a dispersion of magnesium borohydride and magnesium oxide nanoparticles in polyethylene oxide. Rechargeable magnesium batteries including the disclosed solid-state electrolyte may have a coulombic efficiency .gtoreq.95% and exhibit cycling stability for at least 50 cycles.

  6. Artificial recharge of humic ground water.

    PubMed

    Alborzfar, M; Villumsen, A; Grøn, C

    2001-01-01

    The purpose of this study was to investigate the efficiency of soil in removing natural organic matter from humic ground waters using artificial recharge. The study site, in western Denmark, was a 10,000 ml football field of which 2,000 m2 served as an infiltration field. The impact of the artificial recharge was studied by monitoring the water level and the quality of the underlying shallow aquifer. The humic ground water contained mainly humic adds with an organic carbon (OC) concentration of 100 to 200 mg C L(-1). A total of 5,000 mS of humic ground water were sprinkled onto the infiltration field at an average rate of 4.25 mm h(-1). This resulted in a rise in the water table of the shallow aquifer. The organic matter concentration of the water in the shallow aquifer, however, remained below 2.7 mg C L(-1). The organic matter concentration of the pore water in the unsaturated zone was measured at the end of the experiment. The organic matter concentration of the pore water decreased from 105 mg C L(-1) at 0.5 m to 20 mg C L(-1) at 2.5 m under the infiltration field indicating that the soil removed the organic matter from the humic ground water. From these results we conclude that artificial recharge is a possible method for humic ground water treatment.

  7. Quantifying Potential Groundwater Recharge In South Texas

    NASA Astrophysics Data System (ADS)

    Basant, S.; Zhou, Y.; Leite, P. A.; Wilcox, B. P.

    2015-12-01

    Groundwater in South Texas is heavily relied on for human consumption and irrigation for food crops. Like most of the south west US, woody encroachment has altered the grassland ecosystems here too. While brush removal has been widely implemented in Texas with the objective of increasing groundwater recharge, the linkage between vegetation and groundwater recharge in South Texas is still unclear. Studies have been conducted to understand plant-root-water dynamics at the scale of plants. However, little work has been done to quantify the changes in soil water and deep percolation at the landscape scale. Modeling water flow through soil profiles can provide an estimate of the total water flowing into deep percolation. These models are especially powerful with parameterized and calibrated with long term soil water data. In this study we parameterize the HYDRUS soil water model using long term soil water data collected in Jim Wells County in South Texas. Soil water was measured at every 20 cm intervals up to a depth of 200 cm. The parameterized model will be used to simulate soil water dynamics under a variety of precipitation regimes ranging from well above normal to severe drought conditions. The results from the model will be compared with the changes in soil moisture profile observed in response to vegetation cover and treatments from a study in a similar. Comparative studies like this can be used to build new and strengthen existing hypotheses regarding deep percolation and the role of soil texture and vegetation in groundwater recharge.

  8. Where the Caledonides crosses the Grenville: The Grenvillian Glenelg Inlier as an allochthonous pip within a fold-nappe complex in the Scottish Caledonides

    NASA Astrophysics Data System (ADS)

    Krabbendam, M.; Ramsay, J. G.; Leslie, A. G.; Tanner, P. W. G.; Dietrich, D.; Goodenough, K. M.

    2012-04-01

    The Grenvillian (1100 - 990 Ma) and Caledonian (470-420 Ma) orogenies represent pivotal tectonic events in the evolution of Laurentia and Baltica. Significantly, these two orogenic belts lie at a high angle to one another, with an inferred intersection in NW Scotland. This relationship is most readily examined at the Glenelg Inlier of NW Scotland, a basement gneiss inlier within the Scottish Caledonides nappe pile. This inlier contains a Western Glenelg Inlier, composed of orthogneiss with no record of Grenville metamorphism, and a separate Eastern Glenelg Inlier, comprising both ortho-and paragneisses that experienced Grenvillian eclogite-facies metamorphism. The two components of the Glenelg Inlier are interleaved and/or infolded with locally unconformable, basal Moine Supergroup metasediments, deposited (just) after Grenvillian orogenesis. The inlier and the metasediments are now located in the hanging wall of the well-studied Caledonian Moine Thrust. Despite decades of research and classical structural studies, the overall geometry and structural evolution of the Glenelg Inlier and the surrounding Moine metasediments remain elusive. The synthesis presented here is based upon both new, and hitherto unpublished, mapping. The Glenelg Inlier and enclosing Moine were deformed by three generations of major ductile fold structures (F1-F3). In areas of medium strain, away from the basement inliers, F2 and F3 large-scale structures face and verge towards the west, and record coaxial interference patterns. In areas of higher strain, F2 fold axes were rotated into parallelism with the (westerly) transport direction. Subsequent refolding of these F2 folds by west-vergent (N-S trending) F3 folds led in some areas to high-angle, non-coaxial fold interference patterns, including dome-and-basin structures. On structural grounds, both F2 and F3 are thought to be of Caledonian age. An approximate restoration of the F2 and F3 folds reveals the pre-F2 basement-cover architecture

  9. A regression model to estimate regional ground water recharge

    USGS Publications Warehouse

    Lorenz, D.L.; Delin, G.N.

    2007-01-01

    A regional regression model was developed to estimate the spatial distribution of ground water recharge in subhumid regions. The regional regression recharge (RRR) model was based on a regression of basin-wide estimates of recharge from surface water drainage basins, precipitation, growing degree days (GDD), and average basin specific yield (SY). Decadal average recharge, precipitation, and GDD were used in the RRR model. The RRR estimates were derived from analysis of stream base flow using a computer program that was based on the Rorabaugh method. As expected, there was a strong correlation between recharge and precipitation. The model was applied to statewide data in Minnesota. Where precipitation was least in the western and northwestern parts of the state (50 to 65 cm/year), recharge computed by the RRR model also was lowest (0 to 5 cm/year). A strong correlation also exists between recharge and SY. SY was least in areas where glacial lake clay occurs, primarily in the northwest part of the state; recharge estimates in these areas were in the 0- to 5-cm/year range. In sand-plain areas where SY is greatest, recharge estimates were in the 15- to 29-cm/year range on the basis of the RRR model. Recharge estimates that were based on the RRR model compared favorably with estimates made on the basis of other methods. The RRR model can be applied in other subhumid regions where region wide data sets of precipitation, streamflow, GDD, and soils data are available.

  10. A regression model to estimate regional ground water recharge.

    PubMed

    Lorenz, David L; Delin, Geoffrey N

    2007-01-01

    A regional regression model was developed to estimate the spatial distribution of ground water recharge in subhumid regions. The regional regression recharge (RRR) model was based on a regression of basin-wide estimates of recharge from surface water drainage basins, precipitation, growing degree days (GDD), and average basin specific yield (SY). Decadal average recharge, precipitation, and GDD were used in the RRR model. The RRR estimates were derived from analysis of stream base flow using a computer program that was based on the Rorabaugh method. As expected, there was a strong correlation between recharge and precipitation. The model was applied to statewide data in Minnesota. Where precipitation was least in the western and northwestern parts of the state (50 to 65 cm/year), recharge computed by the RRR model also was lowest (0 to 5 cm/year). A strong correlation also exists between recharge and SY. SY was least in areas where glacial lake clay occurs, primarily in the northwest part of the state; recharge estimates in these areas were in the 0- to 5-cm/year range. In sand-plain areas where SY is greatest, recharge estimates were in the 15- to 29-cm/year range on the basis of the RRR model. Recharge estimates that were based on the RRR model compared favorably with estimates made on the basis of other methods. The RRR model can be applied in other subhumid regions where region wide data sets of precipitation, streamflow, GDD, and soils data are available.

  11. Insights on high-grade deformation in quartzo-feldspathic gneisses during the early Variscan exhumation of the Cabo Ortegal nappe, NW Iberia

    NASA Astrophysics Data System (ADS)

    José Fernández, Francisco; Llana-Fúnez, Sergio; Valverde-Vaquero, Pablo; Marcos, Alberto; Castiñeiras, Pedro

    2016-04-01

    High-grade, highly deformed gneisses crop out continuously along the Masanteo peninsula and constitute the upper part of the lower crustal section in the Cabo Ortegal nappe (NW Spain). The rock sequence formed by migmatitic quartzo-feldspathic (qz-fsp) gneisses and mafic rocks records the early Ordovician (ca. 480-488 Ma) injection of felsic dioritic/granodioritic dykes at the base of the qz-fsp gneisses, and Devonian eclogitization (ca. 390.4 ± 1.2 Ma), prior to its exhumation. A SE-vergent ductile thrust constitutes the base of quartzo-feldspathic gneissic unit, incorporating mafic eclogite blocks within migmatitic gneisses. A NW-vergent detachment displaced metasedimentary qz-fsp gneisses over the migmatites. A difference in metamorphic pressure of ca. 0.5 GPa is estimated between both gneissic units. The tectono-metamorphic relationships of the basal ductile thrust and the normal detachment bounding the top of the migmatites indicate that both discrete mechanical contacts were active before the recumbent folding affecting the sequence of gneisses during their final emplacement. The progressive tectonic exhumation from eclogite to greenschist facies conditions occurred over ca. 10 Ma and involved bulk thinning of the high-grade rock sequence in the high pressure and high temperature (HP-HT) Cabo Ortegal nappe. The necessary strain was accommodated by the development of a widespread main foliation, dominated by flattening, that subsequently localized to a network of anastomosing shear bands that evolved to planar shear zones. Qz-fsp gneisses and neighbouring mafic granulites were exhumed at > 3 mm yr-1, and the exhumation path involved a cooling of ˜ 20 °C/100 MPa, These figures are comparable to currently active subduction zones, although exhumation P-T trajectory and ascent rates are at the hotter and slower end in comparison with currently active similar settings, suggesting an extremely ductile deformation environment during the exhumation of qz

  12. Simulating Groundwater Recharge Across the Southern High Plains

    NASA Astrophysics Data System (ADS)

    Smidt, S. J.; Haacker, E. M.; Kendall, A. D.; Hyndman, D. W.

    2015-12-01

    Quantifying recharge and water availability across the Southern High Plains is a difficult, but necessary, challenge for future groundwater and agricultural projections. Overland flow is not common due to limited precipitation, dry soils, and high evapotranspiration. The majority of runoff is temporarily stored in playa lakes, leading to the bulk of recharge across the region occurring in localized infiltration zones beneath these lakes. Despite the importance of regional recharge estimates, limited information exists that integrates complex characteristics of the land, climate, and hydrology in order to quantify recharge across the entire Southern High Plains aquifer. This study applies the Landscape Hydrology Model (LHM) to capture these characteristics and simulate surface water flow and groundwater recharge. This model simulates the complete water cycle across large regions, including irrigation estimates, establishing a framework to estimate recharge and groundwater availability in the Southern High Plains region. Results from this study can be used to predict the likely impacts of climate change and improve water management strategies.

  13. Regional estimation of total recharge to ground water in Nebraska.

    PubMed

    Szilagyi, Jozsef; Harvey, F Edwin; Ayers, Jerry F

    2005-01-01

    Naturally occurring long-term mean annual recharge to ground water in Nebraska was estimated by a novel water-balance approach. This approach uses geographic information systems (GIS) layers of land cover, elevation of land and ground water surfaces, base recharge, and the recharge potential in combination with monthly climatic data. Long-term mean recharge > 140 mm per year was estimated in eastern Nebraska, having the highest annual precipitation rates within the state, along the Elkhorn, Platte, Missouri, and Big Nemaha River valleys where ground water is very close to the surface. Similarly high recharge values were obtained for the Sand Hills sections of the North and Middle Loup, as well as Cedar River and Beaver Creek valleys due to high infiltration rates of the sandy soil in the area. The westernmost and southwesternmost parts of the state were estimated to typically receive < 30 mm of recharge a year.

  14. Groundwater recharge with reclaimed municipal wastewater: health and regulatory considerations.

    PubMed

    Asano, Takashi; Cotruvo, Joseph A

    2004-04-01

    Groundwater recharge with reclaimed municipal wastewater presents a wide spectrum of technical and health challenges that must be carefully evaluated prior to undertaking a project. This review will provide a discussion of groundwater recharge and its management with special reference to health and regulatory aspects of groundwater recharge with reclaimed municipal wastewater. At present, some uncertainties with respect to health risk considerations have limited expanding use of reclaimed municipal wastewater for groundwater recharge, especially when a large portion of the groundwater contains reclaimed wastewater that may affect the domestic water supply. The proposed State of California criteria for groundwater recharge are discussed as an illustration of a cautious approach. In addition, a summary is provided of the methodology used in developing the World Health Organization's Guidelines for Drinking Water Quality to illustrate how numerical guideline values are generated for contaminants that may be applicable to groundwater recharge. PMID:15087175

  15. Groundwater recharge with reclaimed municipal wastewater: health and regulatory considerations.

    PubMed

    Asano, Takashi; Cotruvo, Joseph A

    2004-04-01

    Groundwater recharge with reclaimed municipal wastewater presents a wide spectrum of technical and health challenges that must be carefully evaluated prior to undertaking a project. This review will provide a discussion of groundwater recharge and its management with special reference to health and regulatory aspects of groundwater recharge with reclaimed municipal wastewater. At present, some uncertainties with respect to health risk considerations have limited expanding use of reclaimed municipal wastewater for groundwater recharge, especially when a large portion of the groundwater contains reclaimed wastewater that may affect the domestic water supply. The proposed State of California criteria for groundwater recharge are discussed as an illustration of a cautious approach. In addition, a summary is provided of the methodology used in developing the World Health Organization's Guidelines for Drinking Water Quality to illustrate how numerical guideline values are generated for contaminants that may be applicable to groundwater recharge.

  16. [Study on the guideline for groundwater recharge with reclaimed water].

    PubMed

    He, Xing-hai; Ma, Shi-hao

    2004-09-01

    Groundwater recharge with reclaimed water is the most beneficial way to extend reuse applications, and has the vast development foreground. In this paper, the domestic and international applications and guidelines for groundwater recharge with reclaimed water were summarized. Based on the quality of reclaimed water and the conditions of hydrological geology, the reclaimed water quality criteria for groundwater recharge was suggested including 22 basic controlling items and 52 selective controlling items, and the control technology was presented. PMID:15623024

  17. [Study on the guideline for groundwater recharge with reclaimed water].

    PubMed

    He, Xing-hai; Ma, Shi-hao

    2004-09-01

    Groundwater recharge with reclaimed water is the most beneficial way to extend reuse applications, and has the vast development foreground. In this paper, the domestic and international applications and guidelines for groundwater recharge with reclaimed water were summarized. Based on the quality of reclaimed water and the conditions of hydrological geology, the reclaimed water quality criteria for groundwater recharge was suggested including 22 basic controlling items and 52 selective controlling items, and the control technology was presented.

  18. Making Li-air batteries rechargeable: material challenges

    SciTech Connect

    Shao, Yuyan; Ding, Fei; Xiao, Jie; Zhang, Jian; Xu, Wu; Park, Seh Kyu; Zhang, Jiguang; Wang, Yong; Liu, Jun

    2013-02-25

    A Li-air battery could potentially provide three to five times higher energy density/specific energy than conventional batteries, thus enable the driving range of an electric vehicle comparable to a gasoline vehicle. However, making Li-air batteries rechargeable presents significant challenges, mostly related with materials. Herein, we discuss the key factors that influence the rechargeability of Li-air batteries with a focus on nonaqueous system. The status and materials challenges for nonaqueous rechargeable Li-air batteries are reviewed. These include electrolytes, cathode (electocatalysts), lithium metal anodes, and oxygen-selective membranes (oxygen supply from air). The perspective of rechargeable Li-air batteries is provided.

  19. A review of groundwater recharge under irrigated agriculture in Australia

    NASA Astrophysics Data System (ADS)

    Riasat, Ali; Mallants, Dirk; Walker, Glen; Silberstein, Richard

    2014-05-01

    Quantification of recharge under irrigated agriculture is one of the most important but difficult tasks. It is the least understood component in groundwater studies because of its large variability in space and time and the difficulty of direct measurement. Better management of groundwater resources is only possible if we can accurately determine all fluxes going into and out of a groundwater system. One of the major challenges facing irrigated agriculture in Australia, and the world, is to reduce uncertainty in estimating or measuring the recharge flux. Reducing uncertainty in groundwater recharge under irrigated agriculture is a pre-requisite for effective, efficient and sustainable groundwater resource management especially in dry areas where groundwater usage is often the key to economic development. An accurate quantification of groundwater recharge under irrigated systems is also crucial because of its potential impacts on soil profile salinity, groundwater levels and groundwater quality. This paper aims to identify the main recharge control parameters thorough a review of past field and modelling recharge studies in Australia. We find that the main recharge control parameters under irrigated agriculture are soil type, irrigation management, watertable depth, land cover or plant water uptake, soil surface conditions, and soil, irrigation water and groundwater chemistry. The most commonly used recharge estimation approaches include chloride mass balance, water budget equation, lysimeters, Darcy's law and numerical models. Main sources and magnitude of uncertainty in recharge estimates associated with these approaches are discussed.

  20. Recycling of used Ni-MH rechargeable batteries

    SciTech Connect

    Yoshida, T.; Ono, H.; Shirai, R.

    1995-12-31

    The Ni-MH (nickel metal hydride) rechargeable battery was developed several years ago. Its higher electrochemical capacity and greater safety compared with the Ni-Cd rechargeable battery have resulted in very rapid increase in its production. The Ni-MH rechargeable battery consists of Ni, Co and rare earth metals, so that recycling is important to recover these valuable mineral resources. In this study, a basic recycling process for used Ni-MH rechargeable batteries has been developed, in which the Ni, Co and rare earth elements are recovered through a combination of mechanical processing and hydrometallurgical processing.

  1. An ultrafast rechargeable aluminium-ion battery.

    PubMed

    Lin, Meng-Chang; Gong, Ming; Lu, Bingan; Wu, Yingpeng; Wang, Di-Yan; Guan, Mingyun; Angell, Michael; Chen, Changxin; Yang, Jiang; Hwang, Bing-Joe; Dai, Hongjie

    2015-04-16

    The development of new rechargeable battery systems could fuel various energy applications, from personal electronics to grid storage. Rechargeable aluminium-based batteries offer the possibilities of low cost and low flammability, together with three-electron-redox properties leading to high capacity. However, research efforts over the past 30 years have encountered numerous problems, such as cathode material disintegration, low cell discharge voltage (about 0.55 volts; ref. 5), capacitive behaviour without discharge voltage plateaus (1.1-0.2 volts or 1.8-0.8 volts) and insufficient cycle life (less than 100 cycles) with rapid capacity decay (by 26-85 per cent over 100 cycles). Here we present a rechargeable aluminium battery with high-rate capability that uses an aluminium metal anode and a three-dimensional graphitic-foam cathode. The battery operates through the electrochemical deposition and dissolution of aluminium at the anode, and intercalation/de-intercalation of chloroaluminate anions in the graphite, using a non-flammable ionic liquid electrolyte. The cell exhibits well-defined discharge voltage plateaus near 2 volts, a specific capacity of about 70 mA h g(-1) and a Coulombic efficiency of approximately 98 per cent. The cathode was found to enable fast anion diffusion and intercalation, affording charging times of around one minute with a current density of ~4,000 mA g(-1) (equivalent to ~3,000 W kg(-1)), and to withstand more than 7,500 cycles without capacity decay. PMID:25849777

  2. An ultrafast rechargeable aluminium-ion battery.

    PubMed

    Lin, Meng-Chang; Gong, Ming; Lu, Bingan; Wu, Yingpeng; Wang, Di-Yan; Guan, Mingyun; Angell, Michael; Chen, Changxin; Yang, Jiang; Hwang, Bing-Joe; Dai, Hongjie

    2015-04-16

    The development of new rechargeable battery systems could fuel various energy applications, from personal electronics to grid storage. Rechargeable aluminium-based batteries offer the possibilities of low cost and low flammability, together with three-electron-redox properties leading to high capacity. However, research efforts over the past 30 years have encountered numerous problems, such as cathode material disintegration, low cell discharge voltage (about 0.55 volts; ref. 5), capacitive behaviour without discharge voltage plateaus (1.1-0.2 volts or 1.8-0.8 volts) and insufficient cycle life (less than 100 cycles) with rapid capacity decay (by 26-85 per cent over 100 cycles). Here we present a rechargeable aluminium battery with high-rate capability that uses an aluminium metal anode and a three-dimensional graphitic-foam cathode. The battery operates through the electrochemical deposition and dissolution of aluminium at the anode, and intercalation/de-intercalation of chloroaluminate anions in the graphite, using a non-flammable ionic liquid electrolyte. The cell exhibits well-defined discharge voltage plateaus near 2 volts, a specific capacity of about 70 mA h g(-1) and a Coulombic efficiency of approximately 98 per cent. The cathode was found to enable fast anion diffusion and intercalation, affording charging times of around one minute with a current density of ~4,000 mA g(-1) (equivalent to ~3,000 W kg(-1)), and to withstand more than 7,500 cycles without capacity decay.

  3. Geophysical Methods for Investigating Ground-Water Recharge

    USGS Publications Warehouse

    Ferre, Ty P.A.; Binley, Andrew M.; Blasch, Kyle W.; Callegary, James B.; Crawford, Steven M.; Fink, James B.; Flint, Alan L.; Flint, Lorraine E.; Hoffmann, John P.; Izbicki, John A.; Levitt, Marc T.; Pool, Donald R.; Scanlon, Bridget R.

    2007-01-01

    While numerical modeling has revolutionized our understanding of basin-scale hydrologic processes, such models rely almost exclusively on traditional measurements?rainfall, streamflow, and water-table elevations?for calibration and testing. Model calibration provides initial estimates of ground-water recharge. Calibrated models are important yet crude tools for addressing questions about the spatial and temporal distribution of recharge. An inverse approach to recharge estimation is taken of necessity, due to inherent difficulties in making direct measurements of flow across the water table. Difficulties arise because recharging fluxes are typically small, even in humid regions, and because the location of the water table changes with time. Deep water tables in arid and semiarid regions make recharge monitoring especially difficult. Nevertheless, recharge monitoring must advance in order to improve assessments of ground-water recharge. Improved characterization of basin-scale recharge is critical for informed water-resources management. Difficulties in directly measuring recharge have prompted many efforts to develop indirect methods. The mass-balance approach of estimating recharge as the residual of generally much larger terms has persisted despite the use of increasing complex and finely gridded large-scale hydrologic models. Geophysical data pertaining to recharge rates, timing, and patterns have the potential to substantially improve modeling efforts by providing information on boundary conditions, by constraining model inputs, by testing simplifying assumptions, and by identifying the spatial and temporal resolutions needed to predict recharge to a specified tolerance in space and in time. Moreover, under certain conditions, geophysical measurements can yield direct estimates of recharge rates or changes in water storage, largely eliminating the need for indirect measures of recharge. This appendix presents an overview of physically based, geophysical methods

  4. Evolution of strategies for modern rechargeable batteries.

    PubMed

    Goodenough, John B

    2013-05-21

    This Account provides perspective on the evolution of the rechargeable battery and summarizes innovations in the development of these devices. Initially, I describe the components of a conventional rechargeable battery along with the engineering parameters that define the figures of merit for a single cell. In 1967, researchers discovered fast Na(+) conduction at 300 K in Na β,β''-alumina. Since then battery technology has evolved from a strongly acidic or alkaline aqueous electrolyte with protons as the working ion to an organic liquid-carbonate electrolyte with Li(+) as the working ion in a Li-ion battery. The invention of the sodium-sulfur and Zebra batteries stimulated consideration of framework structures as crystalline hosts for mobile guest alkali ions, and the jump in oil prices in the early 1970s prompted researchers to consider alternative room-temperature batteries with aprotic liquid electrolytes. With the existence of Li primary cells and ongoing research on the chemistry of reversible Li intercalation into layered chalcogenides, industry invested in the production of a Li/TiS2 rechargeable cell. However, on repeated recharge, dendrites grew across the electrolyte from the anode to the cathode, leading to dangerous short-circuits in the cell in the presence of the flammable organic liquid electrolyte. Because lowering the voltage of the anode would prevent cells with layered-chalcogenide cathodes from competing with cells that had an aqueous electrolyte, researchers quickly abandoned this effort. However, once it was realized that an oxide cathode could offer a larger voltage versus lithium, researchers considered the extraction of Li from the layered LiMO2 oxides with M = Co or Ni. These oxide cathodes were fabricated in a discharged state, and battery manufacturers could not conceive of assembling a cell with a discharged cathode. Meanwhile, exploration of Li intercalation into graphite showed that reversible Li insertion into carbon occurred

  5. Evolution of strategies for modern rechargeable batteries.

    PubMed

    Goodenough, John B

    2013-05-21

    This Account provides perspective on the evolution of the rechargeable battery and summarizes innovations in the development of these devices. Initially, I describe the components of a conventional rechargeable battery along with the engineering parameters that define the figures of merit for a single cell. In 1967, researchers discovered fast Na(+) conduction at 300 K in Na β,β''-alumina. Since then battery technology has evolved from a strongly acidic or alkaline aqueous electrolyte with protons as the working ion to an organic liquid-carbonate electrolyte with Li(+) as the working ion in a Li-ion battery. The invention of the sodium-sulfur and Zebra batteries stimulated consideration of framework structures as crystalline hosts for mobile guest alkali ions, and the jump in oil prices in the early 1970s prompted researchers to consider alternative room-temperature batteries with aprotic liquid electrolytes. With the existence of Li primary cells and ongoing research on the chemistry of reversible Li intercalation into layered chalcogenides, industry invested in the production of a Li/TiS2 rechargeable cell. However, on repeated recharge, dendrites grew across the electrolyte from the anode to the cathode, leading to dangerous short-circuits in the cell in the presence of the flammable organic liquid electrolyte. Because lowering the voltage of the anode would prevent cells with layered-chalcogenide cathodes from competing with cells that had an aqueous electrolyte, researchers quickly abandoned this effort. However, once it was realized that an oxide cathode could offer a larger voltage versus lithium, researchers considered the extraction of Li from the layered LiMO2 oxides with M = Co or Ni. These oxide cathodes were fabricated in a discharged state, and battery manufacturers could not conceive of assembling a cell with a discharged cathode. Meanwhile, exploration of Li intercalation into graphite showed that reversible Li insertion into carbon occurred

  6. Cycle life sensor for rechargeable lithium batteries

    NASA Astrophysics Data System (ADS)

    Nanjundiah, C.; Koch, V. R.

    The problem of characterizing the state of a rechargeable Li battery as a function of cycle life history was addressed. A 50-micron dia Pt microelectrode embedded in the cell package was used as a sensing electrode. Good correlations between Li stripping currents and cycle life were achieved in Li/Li half cells. However, no systematic trends were observed in Li/TiS2 ful cells. Additionally, Li-electrolyte degradation products were found to be either insoluble or electroinactive over the available electrochemical window.

  7. Organic Cathode Materials for Rechargeable Batteries

    SciTech Connect

    Cao, Ruiguo; Qian, Jiangfeng; Zhang, Jiguang; Xu, Wu

    2015-06-28

    This chapter will primarily focus on the advances made in recent years and specify the development of organic electrode materials for their applications in rechargeable lithium batteries, sodium batteries and redox flow batteries. Four various organic cathode materials, including conjugated carbonyl compounds, conducting polymers, organosulfides and free radical polymers, are introduced in terms of their electrochemical performances in these three battery systems. Fundamental issues related to the synthesis-structure-activity correlations, involved work principles in energy storage systems, and capacity fading mechanisms are also discussed.

  8. Thin-film Rechargeable Lithium Batteries

    DOE R&D Accomplishments Database

    Dudney, N. J.; Bates, J. B.; Lubben, D.

    1995-06-01

    Thin film rechargeable lithium batteries using ceramic electrolyte and cathode materials have been fabricated by physical deposition techniques. The lithium phosphorous oxynitride electrolyte has exceptional electrochemical stability and a good lithium conductivity. The lithium insertion reaction of several different intercalation materials, amorphous V{sub 2}O{sub 5}, amorphous LiMn{sub 2}O{sub 4}, and crystalline LiMn{sub 2}O{sub 4} films, have been investigated using the completed cathode/electrolyte/lithium thin film battery.

  9. Crash test for groundwater recharge models: The effects of model complexity and calibration period on groundwater recharge predictions

    NASA Astrophysics Data System (ADS)

    Moeck, Christian; Von Freyberg, Jana; Schrimer, Maria

    2016-04-01

    An important question in recharge impact studies is how model choice, structure and calibration period affect recharge predictions. It is still unclear if a certain model type or structure is less affected by running the model on time periods with different hydrological conditions compared to the calibration period. This aspect, however, is crucial to ensure reliable predictions of groundwater recharge. In this study, we quantify and compare the effect of groundwater recharge model choice, model parametrization and calibration period in a systematic way. This analysis was possible thanks to a unique data set from a large-scale lysimeter in a pre-alpine catchment where daily long-term recharge rates are available. More specifically, the following issues are addressed: We systematically evaluate how the choice of hydrological models influences predictions of recharge. We assess how different parameterizations of models due to parameter non-identifiability affect predictions of recharge by applying a Monte Carlo approach. We systematically assess how the choice of calibration periods influences predictions of recharge within a differential split sample test focusing on the model performance under extreme climatic and hydrological conditions. Results indicate that all applied models (simple lumped to complex physically based models) were able to simulate the observed recharge rates for five different calibration periods. However, there was a marked impact of the calibration period when the complete 20 years validation period was simulated. Both, seasonal and annual differences between simulated and observed daily recharge rates occurred when the hydrological conditions were different to the calibration period. These differences were, however, less distinct for the physically based models, whereas the simpler models over- or underestimate the observed recharge depending on the considered season. It is, however, possible to reduce the differences for the simple models by

  10. The not trivial subdivision of nappes in the Lower Pennine domain of the Central Alps (Riviera and Verzasca Valleys, Swiss Alps)

    NASA Astrophysics Data System (ADS)

    Schenker, Filippo Luca; Ambrosi, Christian; Scapozza, Cristian; Castelletti, Claudio; Maino, Matteo; Gouffon, Yves

    2016-04-01

    We present new data of the geological map of the Osogna sheet in the Southern Swiss Alps (Swiss National Map no. 1293) that extends N-S from Biasca to Claro and W-E from Lavertezzo to the Pizzo di Claro, respectively. The area mapped at the 1:10'000 scale is located in the Lepontine dome and includes, from core-to-carapace, the gneissic nappes of the Leventina, Simano, Adula/Cima-Lunga and Maggia. These nappes derive from the same post-Variscan gneissic basement complicating their lithological distinction and making difficult to recognize their boundaries. In particular, the boundary between the Leventina and the Simano gneisses is difficult to recognize. In previous work, this boundary was traced within leucogneisses by joining a carbonate lens with quartzite, amphibolite or paragneiss lenses. Nevertheless, quartzites are absent in the mapped area and amphibolite and paragneiss lenses are vertically distributed in the tectonostratigraphy and do not form a single folded horizon. Furthermore, no significant strain gradient related to top-to-the-foreland shearing has been observed between these two units, also when paragneisses and amphibolites were present. Therefore, we present evidence that the top-to-the-foreland deformation between the Leventina and the Simano units was more distributed that commonly assumed, questioning the allochthonous character of the Simano unit.

  11. Kyanite-garnet gneisses of the Kåfjord Nappe - North Norwegian Caledonides: P-T conditions and monazite Th-U-Pb dating

    NASA Astrophysics Data System (ADS)

    Ziemniak, Grzegorz; Kośmińska, Karolina; Majka, Jarosław; Janák, Marian; Manecki, Maciej

    2016-04-01

    The Kåfjord Nappe is the part of the Skibotn Nappe Complex traditionally ascribed to the Upper Allochthon of the North Norwegian Caledonides. Pressure-temperature (P-T) conditions and metamorphic age of the Kåfjord Nappe are not well constrained, geochronological data are limited to a single Rb-Sr age of c. 440 Ma (Dangla et al. 1978). Metamorphic evolution of kyanite-garnet gneisses of the Kåfjord Nappe is presented here. The kyanite-garnet gneisses are associated with a few meters thick amphibolite lenses. The gneisses mainly consist of quartz, plagioclase, biotite, muscovite, garnet, kyanite, and rutile. Retrograde minerals are represented by sillimanite and chlorite. Garnet occurs as two textural types. Garnet-I forms euhedral porphyroblasts with multiple small inclusions. Profiles through garnet-I show chemical zonation in all components. The composition varies from Alm64-68Prp11-16Grs13-18Sps2-8 in the core to Alm68-70Prp17-18Grs10-13Sps1-3 in the rim. Garnet-II is subhedral to anhedral, its core is inclusion-rich, whereas rim contains only single inclusions. Chemical composition of garnet-II is similar to that of the garnet-I rim. P-T conditions have been estimated using the garnet-biotite-muscovite-plagioclase (GBPM) geothermobarometer (Holdaway, 2001; Wu, 2014). Calculated peak P-T metamorphic conditions are 610-625 °C and 7.6-8.2 kbar corresponding to the amphibolite facies conditions. Phase equilibrium modelling in the NCKFMMnASH system yields peak metamorphic conditions of c. 620 °C at 8 kbar. Growth conditions of garnet-I core modelled in the NCKFMMnASH system are c. 570 °C at 9.7 kbar. Chemical Th-U-total Pb monazite dating has been performed. Preliminary dating results from the kyanite-garnet gneiss of the Kåfjord Nappe yield an array of dates from 468 Ma to 404 Ma. There is a correlation between an increase of yttrium content and decrease of monazite single dates. Compositional maps confirm an increase of yttrium towards the rim of the

  12. Sediment and microbial fouling of experimental groundwater recharge trenches

    NASA Astrophysics Data System (ADS)

    Warner, James W.; Gates, Timothy K.; Namvargolian, Reza; Miller, Paul; Comes, Gregory

    1994-04-01

    A common method of recharging groundwater is by the use of injection wells and/or recharge trenches. With time the recharge capacities of the wells/trenches progressively decline. Deposition of suspended fines in the recharge water and growth of microorganisms in the aquifer are common causes of this decline. This paper presents an investigation of the relative significance of these two factors under controlled laboratory conditions. Large-scale physical models of recharge trenches were conducted in the laboratory to monitor the decline with time of the recharge capacity under controlled conditions. The physical models consisted of four hydraulically separate cells in which six different experiments were conducted. In three of the experiments microorganism were added as an inoculant. A nutrient and carbon fine solution was constantly injected into the influent stream entering through the inflow pipe. Both carbon fines and microorganisms caused plugging of the model recharge trenches in the laboratory. However, initialy the microbes appeared to have a beneficial effect by hindering the transport of the carbon fines from the gravel pack in the trench. Later the microbes contributed to the plugging of the gravel pack. A significant correlation was determined between the extent of carbon fine deposition and microbial growth. In the experiment using a biodegradable slurry, microbial growth did not affect the recharge capacity of the trench. One laboratory experiment involved the introduction of silt as a source of sediment fines to the model recharge trench. This experiment simulated conditions often found in the field when no carbon fine adsoprtion system is used and natural surface water is recharged into aquifer. This research will be useful in understanding the relative importance of factors contributing to the decline of recharge capacity observed in the field.

  13. Challenges of Artificial Recharge at the Chain of Lakes

    NASA Astrophysics Data System (ADS)

    Zeng, X.

    2004-12-01

    A series of gravel quarry lakes, A through I (i.e. Chain of Lakes) in Alameda County, California are planned to convert to off-channel spreading lakes for artificial groundwater recharge. An operational plan is needed for the near-term improvements that would allow safe and efficient operations of Lake H and Lake I recently acquired for artificial recharge operations. Water source for the groundwater recharge comes from State Water Project (SWP) water releases at the South Bay Aqueduct turnout. The released water flows approximately nine miles in Arroyo Mocho Creek to the planned diversion facility. The recharge system includes multiple water delivery components and recharge components. Reliability of SWP water delivery is a water supply constraint to the recharge system. Hydraulic capacities of each delivery component and recharge capacities of each recharge component are physical constraints to the development of the operational plan. Policy issues identified in the Mitigated Negative Declaration which contains mitigation measures addressing potential impacts of fisheries and erosion are regulatory constraints to the operational plan development. Our approach that addresses technical challenges and policy issues in the development of the operational plan includes i) determination of lake recharge under observed conditions using water budget method; ii) development and calibration of a ground water flow model using MODFLOW; iii) estimation of lake recharge capacity for a range of lake levels using the calibrated ground water flow model; iv) analysis of clogging layer effects on recharge capacity; and v) development and application of operations models for the stream delivery system and the lake system.

  14. Using noble gases to investigate mountain-front recharge

    USGS Publications Warehouse

    Manning, A.H.; Solomon, D.K.

    2003-01-01

    Mountain-front recharge is a major component of recharge to inter-mountain basin-fill aquifers. The two components of mountain-front recharge are (1) subsurface inflow from the mountain block (subsurface inflow), and (2) infiltration from perennial and ephemeral streams near the mountain front (stream seepage). The magnitude of subsurface inflow is of central importance in source protection planning for basin-fill aquifers and in some water rights disputes, yet existing estimates carry large uncertainties. Stable isotope ratios can indicate the magnitude of mountain-front recharge relative to other components, but are generally incapable of distinguishing subsurface inflow from stream seepage. Noble gases provide an effective tool for determining the relative significance of subsurface inflow, specifically. Dissolved noble gas concentrations allow for the determination of recharge temperature, which is correlated with recharge elevation. The nature of this correlation cannot be assumed, however, and must be derived for the study area. The method is applied to the Salt Lake Valley Principal Aquifer in northern Utah to demonstrate its utility. Samples from 16 springs and mine tunnels in the adjacent Wasatch Mountains indicate that recharge temperature decreases with elevation at about the same rate as the mean annual air temperature, but is on average about 2??C cooler. Samples from 27 valley production wells yield recharge elevations ranging from the valley elevation (about 1500 m) to mid-mountain elevation (about 2500 m). Only six of the wells have recharge elevations less than 1800 m. Recharge elevations consistently greater than 2000 m in the southeastern part of the basin indicate that subsurface inflow constitutes most of the total recharge in this area. ?? 2003 Published by Elsevier Science B.V.

  15. Artificial recharge of groundwater and its role in water management

    USGS Publications Warehouse

    Kimrey, J.O.

    1989-01-01

    This paper summarizes and discusses the various aspects and methods of artificial recharge with particular emphasis on its uses and potential role in water management in the Arabian Gulf region. Artificial recharge occurs when man's activities cause more water to enter an aquifer, either under pumping or non-pumping conditions, than otherwise would enter the aquifer. Use of artificial recharge can be a practical means of dealing with problems of overdraft of groundwater. Methods of artificial recharge may be grouped under two broad types: (a) water spreading techniques, and (b) well-injection techniques. Successful use of artificial recharge requires a thorough knowledge of the physical and chemical characteristics of the aquifier system, and extensive onsite experimentation and tailoring of the artificial-recharge technique to fit the local or areal conditions. In general, water spreading techniques are less expensive than well injection and large quantities of water can be handled. Water spreading can also result in significant improvement in quality of recharge waters during infiltration and movement through the unsaturated zone and the receiving aquifer. In comparison, well-injection techniques are often used for emplacement of fresh recharge water into saline aquifer zones to form a manageable lens of fresher water, which may later be partially withdrawn for use or continue to be maintained as a barrier against salt-water encroachment. A major advantage in use of groundwater is its availability, on demand to wells, from a natural storage reservoir that is relatively safe from pollution and from damage by sabotage or other hostile action. However, fresh groundwater occurs only in limited quantities in most of the Arabian Gulf region; also, it is heavily overdrafted in many areas, and receives very little natural recharge. Good use could be made of artificial recharge by well injection in replenishing and managing aquifers in strategic locations if sources of

  16. Lithium Metal Anodes for Rechargeable Batteries

    SciTech Connect

    Xu, Wu; Wang, Jiulin; Ding, Fei; Chen, Xilin; Nasybulin, Eduard N.; Zhang, Yaohui; Zhang, Jiguang

    2013-10-29

    Rechargeable lithium metal batteries have much higher energy density than those of lithium ion batteries using graphite anode. Unfortunately, uncontrollable dendritic lithium growth inherent in these batteries (upon repeated charge/discharge cycling) and limited Coulombic efficiency during lithium deposition/striping has prevented their practical application over the past 40 years. With the emerging of post Li-ion batteries, safe and efficient operation of lithium metal anode has become an enabling technology which may determine the fate of several promising candidates for the next generation of energy storage systems, including rechargeable Li-air battery, Li-S battery, and Li metal battery which utilize lithium intercalation compounds as cathode. In this work, various factors which affect the morphology and Coulombic efficiency of lithium anode will be analyzed. Technologies used to characterize the morphology of lithium deposition and the results obtained by modeling of lithium dendrite growth will also be reviewed. At last, recent development in this filed and urgent need in this field will also be discussed.

  17. Controlled induced recharge tests at Kalamazoo, Michigan

    USGS Publications Warehouse

    Deutsch, Morris

    1962-01-01

    This article discusses the results of a controlled field testing program, which indicated that definite hydraulic and other advantages may be gained from induced recharging as practiced at Kalamazoo, Michigan. Results include the following: water levels and artesian pressures can be maintained at high stages, the results are lower pumping lifts and substantial reductions in the amount of power used for pumping; the high water levels permit increased rates of withdrawal during periods of peak demand; encroachment of poor quality water from other aquifers is minimized; the surface water induced into the aquifer is filtered naturally through great thicknesses of earth materials; natural underground storage is used to conserve and protect water, which otherwise would flow largely to waste; and, significant supplemental benefits, including flood control, have been derived. The tests demonstrated that it is possible to manipulate the regimen of a complex hydrologic system for definite hydraulic benefits with predictable results. Furthermore with current methods, quantitative evaluations may be made of the effects of induced recharge. The results of the tests, therefore, are applicable in other areas of similar hydrogeologic environments.

  18. Rechargeable Thin-film Lithium Batteries

    DOE R&D Accomplishments Database

    Bates, J. B.; Gruzalski, G. R.; Dudney, N. J.; Luck, C. F.; Yu, Xiaohua

    1993-08-01

    Rechargeable thin film batteries consisting of lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have recently been developed. The batteries, which are typically less than 6 {mu}m thick, can be fabricated to any specified size, large or small, onto a variety of substrates including ceramics, semiconductors, and plastics. The cells that have been investigated include Li TiS{sub 2}, Li V{sub 2}O{sub 5}, and Li Li{sub x}Mn{sub 2}O{sub 4}, with open circuit voltages at full charge of about 2.5, 3.6, and 4.2, respectively. The development of these batteries would not have been possible without the discovery of a new thin film lithium electrolyte, lithium phosphorus oxynitride, that is stable in contact with metallic lithium at these potentials. Deposited by rf magnetron sputtering of Li{sub 3}PO{sub 4} in N{sub 2}, this material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46} and a conductivity at 25{degrees}C of 2 {mu}S/cm. The maximum practical current density obtained from the thin film cells is limited to about 100 {mu}A/cm{sup 2} due to a low diffusivity of Li{sup +} ions in the cathodes. In this work, the authors present a short review of their work on rechargeable thin film lithium batteries.

  19. Global synthesis of groundwater recharge in semiarid and arid regions

    NASA Astrophysics Data System (ADS)

    Scanlon, Bridget R.; Keese, Kelley E.; Flint, Alan L.; Flint, Lorraine E.; Gaye, Cheikh B.; Edmunds, W. Michael; Simmers, Ian

    2006-10-01

    Global synthesis of the findings from 140 recharge study areas in semiarid and arid regions provides important information on recharge rates, controls, and processes, which are critical for sustainable water development. Water resource evaluation, dryland salinity assessment (Australia), and radioactive waste disposal (US) are among the primary goals of many of these recharge studies. The chloride mass balance (CMB) technique is widely used to estimate recharge. Average recharge rates estimated over large areas (40-374 000 km2) range from 0.2 to 35 mm year-1, representing 0.1-5% of long-term average annual precipitation. Extreme local variability in recharge, with rates up to 720 m year-1, results from focussed recharge beneath ephemeral streams and lakes and preferential flow mostly in fractured systems. System response to climate variability and land use/land cover (LU/LC) changes is archived in unsaturated zone tracer profiles and in groundwater level fluctuations. Inter-annual climate variability related to El Niño Southern Oscillation (ENSO) results in up to three times higher recharge in regions within the SW US during periods of frequent El Niños (1977-1998) relative to periods dominated by La Niñas (1941-1957). Enhanced recharge related to ENSO is also documented in Argentina. Climate variability at decadal to century scales recorded in chloride profiles in Africa results in recharge rates of 30 mm year-1 during the Sahel drought (1970-1986) to 150 mm year-1 during non-drought periods. Variations in climate at millennial scales in the SW US changed systems from recharge during the Pleistocene glacial period (10 000 years ago) to discharge during the Holocene semiarid period. LU/LC changes such as deforestation in Australia increased recharge up to about 2 orders of magnitude. Changes from natural grassland and shrublands to dryland (rain-fed) agriculture altered systems from discharge (evapotranspiration, ET) to recharge in the SW US. The impact of LU

  20. Global synthesis of groundwater recharge in semiarid and arid regions

    USGS Publications Warehouse

    Scanlon, B.R.; Keese, K.E.; Flint, A.L.; Flint, L.E.; Gaye, C.B.; Edmunds, W.M.; Simmers, I.

    2006-01-01

    Global synthesis of the findings from ???140 recharge study areas in semiarid and arid regions provides important information on recharge rates, controls, and processes, which are critical for sustainable water development. Water resource evaluation, dryland salinity assessment (Australia), and radioactive waste disposal (US) are among the primary goals of many of these recharge studies. The chloride mass balance (CMB) technique is widely used to estimate recharge. Average recharge rates estimated over large areas (40-374000 km2) range from 0.2 to 35 mm year-1, representing 0.1-5% of long-term average annual precipitation. Extreme local variability in recharge, with rates up to ???720 m year-1, results from focussed recharge beneath ephemeral streams and lakes and preferential flow mostly in fractured systems. System response to climate variability and land use/land cover (LU/LC) changes is archived in unsaturated zone tracer profiles and in groundwater level fluctuations. Inter-annual climate variability related to El Nin??o Southern Oscillation (ENSO) results in up to three times higher recharge in regions within the SW US during periods of frequent El Nin??os (1977-1998) relative to periods dominated by La Nin??as (1941-1957). Enhanced recharge related to ENSO is also documented in Argentina. Climate variability at decadal to century scales recorded in chloride profiles in Africa results in recharge rates of 30 mm year-1 during the Sahel drought (1970-1986) to 150 mm year-1 during non-drought periods. Variations in climate at millennial scales in the SW US changed systems from recharge during the Pleistocene glacial period (??? 10 000 years ago) to discharge during the Holocene semiarid period. LU/LC changes such as deforestation in Australia increased recharge up to about 2 orders of magnitude. Changes from natural grassland and shrublands to dryland (rain-fed) agriculture altered systems from discharge (evapotranspiration, ET) to recharge in the SW US. The

  1. Lithium electronic environments in rechargeable battery electrodes

    NASA Astrophysics Data System (ADS)

    Hightower, Adrian

    This work investigates the electronic environments of lithium in the electrodes of rechargeable batteries. The use of electron energy-loss spectroscopy (EELS) in conjunction with transmission electron microscopy (TEM) is a novel approach, which when coupled with conventional electrochemical experiments, yield a thorough picture of the electrode interior. Relatively few EELS experiments have been preformed on lithium compounds owing to their reactivity. Experimental techniques were established to minimize sample contamination and control electron beam damage to studied compounds. Lithium hydroxide was found to be the most common product of beam damaged lithium alloys. Under an intense electron beam, halogen atoms desorbed by radiolysis in lithium halides. EELS spectra from a number of standard lithium compounds were obtained in order to identify the variety of spectra encountered in lithium rechargeable battery electrodes. Lithium alloys all displayed characteristically broad Li K-edge spectra, consistent with transitions to continuum states. Transitions to bound states were observed in the Li K and oxygen K-edge spectra of lithium oxides. Lithium halides were distinguished by their systematic chemical shift proportional to the anion electronegativity. Good agreement was found with measured lithium halide spectra and electron structure calculations using a self-consistant multiscattering code. The specific electrode environments of LiC6, LiCoO2, and Li-SnO were investigated. Contrary to published XPS predictions, lithium in intercalated graphite was determined to be in more metallic than ionic. We present the first experimental evidence of charge compensation by oxygen ions in deintercalated LiCoO2. Mossbauer studies on cycled Li-SnO reveal severely defective structures on an atomic scale. Metal hydride systems are presented in the appendices of this thesis. The mechanical alloying of immiscible Fe and Mg powders resulted in single-phase bcc alloys of less than 20

  2. Improved Recharge Estimation from Portable, Low-Cost Weather Stations.

    PubMed

    Holländer, Hartmut M; Wang, Zijian; Assefa, Kibreab A; Woodbury, Allan D

    2016-03-01

    Groundwater recharge estimation is a critical quantity for sustainable groundwater management. The feasibility and robustness of recharge estimation was evaluated using physical-based modeling procedures, and data from a low-cost weather station with remote sensor techniques in Southern Abbotsford, British Columbia, Canada. Recharge was determined using the Richards-based vadose zone hydrological model, HYDRUS-1D. The required meteorological data were recorded with a HOBO(TM) weather station for a short observation period (about 1 year) and an existing weather station (Abbotsford A) for long-term study purpose (27 years). Undisturbed soil cores were taken at two locations in the vicinity of the HOBO(TM) weather station. The derived soil hydraulic parameters were used to characterize the soil in the numerical model. Model performance was evaluated using observed soil moisture and soil temperature data obtained from subsurface remote sensors. A rigorous sensitivity analysis was used to test the robustness of the model. Recharge during the short observation period was estimated at 863 and 816 mm. The mean annual recharge was estimated at 848 and 859 mm/year based on a time series of 27 years. The relative ratio of annual recharge-precipitation varied from 43% to 69%. From a monthly recharge perspective, the majority (80%) of recharge due to precipitation occurred during the hydrologic winter period. The comparison of the recharge estimates with other studies indicates a good agreement. Furthermore, this method is able to predict transient recharge estimates, and can provide a reasonable tool for estimates on nutrient leaching that is often controlled by strong precipitation events and rapid infiltration of water and nitrate into the soil. PMID:26011672

  3. Groundwater recharge rate and zone structure estimation using PSOLVER algorithm.

    PubMed

    Ayvaz, M Tamer; Elçi, Alper

    2014-01-01

    The quantification of groundwater recharge is an important but challenging task in groundwater flow modeling because recharge varies spatially and temporally. The goal of this study is to present an innovative methodology to estimate groundwater recharge rates and zone structures for regional groundwater flow models. Here, the unknown recharge field is partitioned into a number of zones using Voronoi Tessellation (VT). The identified zone structure with the recharge rates is associated through a simulation-optimization model that couples MODFLOW-2000 and the hybrid PSOLVER optimization algorithm. Applicability of this procedure is tested on a previously developed groundwater flow model of the Tahtalı Watershed. Successive zone structure solutions are obtained in an additive manner and penalty functions are used in the procedure to obtain realistic and plausible solutions. One of these functions constrains the optimization by forcing the sum of recharge rates for the grid cells that coincide with the Tahtalı Watershed area to be equal to the areal recharge rate determined in the previous modeling by a separate precipitation-runoff model. As a result, a six-zone structure is selected as the best zone structure that represents the areal recharge distribution. Comparison to results of a previous model for the same study area reveals that the proposed procedure significantly improves model performance with respect to calibration statistics. The proposed identification procedure can be thought of as an effective way to determine the recharge zone structure for groundwater flow models, in particular for situations where tangible information about groundwater recharge distribution does not exist.

  4. Improved Recharge Estimation from Portable, Low-Cost Weather Stations.

    PubMed

    Holländer, Hartmut M; Wang, Zijian; Assefa, Kibreab A; Woodbury, Allan D

    2016-03-01

    Groundwater recharge estimation is a critical quantity for sustainable groundwater management. The feasibility and robustness of recharge estimation was evaluated using physical-based modeling procedures, and data from a low-cost weather station with remote sensor techniques in Southern Abbotsford, British Columbia, Canada. Recharge was determined using the Richards-based vadose zone hydrological model, HYDRUS-1D. The required meteorological data were recorded with a HOBO(TM) weather station for a short observation period (about 1 year) and an existing weather station (Abbotsford A) for long-term study purpose (27 years). Undisturbed soil cores were taken at two locations in the vicinity of the HOBO(TM) weather station. The derived soil hydraulic parameters were used to characterize the soil in the numerical model. Model performance was evaluated using observed soil moisture and soil temperature data obtained from subsurface remote sensors. A rigorous sensitivity analysis was used to test the robustness of the model. Recharge during the short observation period was estimated at 863 and 816 mm. The mean annual recharge was estimated at 848 and 859 mm/year based on a time series of 27 years. The relative ratio of annual recharge-precipitation varied from 43% to 69%. From a monthly recharge perspective, the majority (80%) of recharge due to precipitation occurred during the hydrologic winter period. The comparison of the recharge estimates with other studies indicates a good agreement. Furthermore, this method is able to predict transient recharge estimates, and can provide a reasonable tool for estimates on nutrient leaching that is often controlled by strong precipitation events and rapid infiltration of water and nitrate into the soil.

  5. Rechargeable high-temperature batteries [Book Chapter

    SciTech Connect

    Cairns, Elton J.

    1981-01-01

    There has been growing research and development effort in the area of high-specific-energy, high-specific-power rechargeable batteries since the mid 1960s and it has been used in electric vehicles, electric utility networks, and solar- and wind-powered electric generator systems. Nonaqueous systems have been found to be the most attractive candidates for the above relatively large-scale applications. Only the high-temperature cells offer the attractive combination of features sought for the cited applications: a specific energy above 100 Wh/kg, a specific power above 100 W/kg, a cycle life in excess of 500 cycles (at 100% depth of discharge), and a projected cost of less than $50† per kWh of energy storage capability.

  6. Rechargeable metal hydrides for spacecraft application

    NASA Technical Reports Server (NTRS)

    Perry, J. L.

    1988-01-01

    Storing hydrogen on board the Space Station presents both safety and logistics problems. Conventional storage using pressurized bottles requires large masses, pressures, and volumes to handle the hydrogen to be used in experiments in the U.S. Laboratory Module and residual hydrogen generated by the ECLSS. Rechargeable metal hydrides may be competitive with conventional storage techniques. The basic theory of hydride behavior is presented and the engineering properties of LaNi5 are discussed to gain a clear understanding of the potential of metal hydrides for handling spacecraft hydrogen resources. Applications to Space Station and the safety of metal hydrides are presented and compared to conventional hydride storage. This comparison indicates that metal hydrides may be safer and require lower pressures, less volume, and less mass to store an equivalent mass of hydrogen.

  7. Oxygen electrodes for rechargeable alkaline fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, Larry; Giner, Jose

    1987-01-01

    Electrocatalysts and supports for the positive electrode of moderate temperature single unit rechargeable alkaline fuel cells were investigated and developed. The electrocatalysts are defined as the material with a higher activity for the oxygen electrode reaction than the support. Advanced development will require that the materials be prepared in high surface area forms, and may also entail integration of various candidate materials. Eight candidate support materials and seven electrocatalysts were investigated. Of the 8 support, 3 materials meet the preliminary requirements in terms of electrical conductivity and stability. Emphasis is now on preparing in high surface area form and testing under more severe corrosion stress conditions. Of the 7 electrocatalysts prepared and evaluated, at least 5 materials remain as potential candidates. The major emphasis remains on preparation, physical characterization and electrochemical performance testing.

  8. Nanostructured cathode materials for rechargeable lithium batteries

    NASA Astrophysics Data System (ADS)

    Myung, Seung-Taek; Amine, Khalil; Sun, Yang-Kook

    2015-06-01

    The prospect of drastic climate change and the ceaseless fluctuation of fossil fuel prices provide motivation to reduce the use of fossil fuels and to find new energy conversion and storage systems that are able to limit carbon dioxide generation. Among known systems, lithium-ion batteries are recognized as the most appropriate energy storage system because of their high energy density and thus space saving in applications. Introduction of nanotechnology to electrode material is beneficial to improve the resulting electrode performances such as capacity, its retention, and rate capability. The nanostructure is highly available not only when used alone but also is more highlighted when harmonized in forms of core-shell structure and composites with carbon nanotubes, graphene or reduced graphene oxides. This review covers syntheses and electrochemical properties of nanoscale, nanosized, and nanostructured cathode materials for rechargeable lithium batteries.

  9. Polymer Energy Rechargeable System (PERS) Development Program

    NASA Technical Reports Server (NTRS)

    Baldwin, Richard S.; Manzo, Michelle A.; Dalton, Penni J.; Marsh, Richard A.; Surampudi, Rao

    2001-01-01

    The National Aeronautics and Space Administration (NASA) and the Air Force Research Laboratory (AFRL) have recently established a collaborative effort to support the development of polymer-based, lithium-based cell chemistries and battery technologies to address the next generation of aerospace applications and mission needs. The overall objective of this development program, which is referred to as PERS, Polymer Energy Rechargeable System, is to establish a world-class technology capability and U.S. leadership in polymer-based battery technology for aerospace applications. Programmatically, the PERS initiative will exploit both interagency collaborations to address common technology and engineering issues and the active participation of academia and private industry. The initial program phases will focus on R&D activities to address the critical technical issues and challenges at the cell level.

  10. Advances in rechargeable lithium molybdenum disulfide batteries

    NASA Technical Reports Server (NTRS)

    Brandt, K.; Stiles, J. A. R.

    1985-01-01

    The lithium molybdenum disulfide system as demonstrated in a C size cell, offers performance characteristics for applications where light weight and low volume are important. A gravimetric energy density of 90 watt hours per kilogram can be achieved in a C size cell package. The combination of charge retention capabilities, high energy density and a state of charge indicator in a rechargeable cell provides power package for a wide range of devices. The system overcomes the memory effect in Nicads where the full capacity of the battery cannot be utilized unless it was utilized on previous cycles. The development of cells with an advanced electrolyte formulation led to an improved rate capability especially at low temperatures and to a significantly improved life cycle.

  11. Unlinkable Priced Oblivious Transfer with Rechargeable Wallets

    NASA Astrophysics Data System (ADS)

    Camenisch, Jan; Dubovitskaya, Maria; Neven, Gregory

    We present the first truly unlinkable priced oblivious transfer protocol. Our protocol allows customers to buy database records while remaining fully anonymous, i.e., (1) the database does not learn who purchases a record, and cannot link purchases by the same customer; (2) the database does not learn which record is being purchased, nor the price of the record that is being purchased; (3) the customer can only obtain a single record per purchase, and cannot spend more than his account balance; (4) the database does not learn the customer's remaining balance. In our protocol customers keep track of their own balances, rather than leaving this to the database as done in previous protocols. Our priced oblivious transfer protocol is also the first to allow customers to (anonymously) recharge their balances. Finally, we prove our protocol secure in the standard model (i.e., without random oracles).

  12. Advanced rechargeable sodium batteries with novel cathodes

    NASA Technical Reports Server (NTRS)

    Di Stefano, S.; Ratnakumar, B. V.; Bankston, C. P.

    1990-01-01

    Various high energy density rechargeable batteries are being considered for future space applications. Of these, the sodium-sulfur battery is one of the leading candidates. The primary advantage is the high energy density (760 W h/kg theoretical). Energy densities in excess of 180 W h/kg have been realized in practical batteries. More recently, cathodes other than sulfur are being evaluated. Various new cathode materials are presently being evaluated for use in high energy density sodium batteries for advanced space applications. The approach is to carry out basic electrochemical studies of these materials in a sodium cell configuration in order to understand their fundamental behaviors. Thus far, the studies have focussed on alternative metal chlorides such as CuCl2 and organic cathode materials such as TCNE.

  13. Advanced rechargeable sodium batteries with novel cathodes

    NASA Technical Reports Server (NTRS)

    Distefano, S.; Ratnakumar, B. V.; Bankston, C. P.

    1989-01-01

    Various high energy density rechargeable batteries are being considered for future space applications. Of these, the sodium sulfur battery is one of the leading candidates. The primary advantage is the high energy density (760 Wh/kg theoretical). Energy densities in excess of 180 Wh/kg have been realized in practical batteries. More recently, cathodes other than sulfur are being evaluated. Researchers at JPL are evaluating various new cathode materials for use in high energy density sodium batteries for advanced space applications. The approach is to carry out basic electrochemical studies of these materials in a sodium cell configuration in order to understand their fundamental behaviors. Thus far studies have focused on alternate metal chlorides such as CuCl2 and organic cathode materials such as tetracyanoethylene (TCNE).

  14. Polymer Energy Rechargeable System Battery Being Developed

    NASA Technical Reports Server (NTRS)

    Manzo, Michelle A.

    2003-01-01

    Long description. Illustrations of discotic liquid crystals, rod-coil polymers, lithium-ion conducting channel dilithium phthalocyanine (Li2Pc) from top and side, novel star polyethylene oxide structures, composite polyethylene oxide materials (showing polyethylene oxide + lithium salt, carbon atoms and oxygen atoms), homopolyrotaxanes, and diblock copolymers In fiscal year 2000, NASA established a program to develop the next generation, lithium-based, polymer electrolyte batteries for aerospace applications. The goal of this program, known as Polymer Energy Rechargeable Systems (PERS), is to develop a space-qualified, advanced battery system embodying polymer electrolyte and lithium-based electrode technologies and to establish world-class domestic manufacturing capabilities for advanced batteries with improved performance characteristics that address NASA s future aerospace battery requirements.

  15. Monitoring of recharge water quality under woodland

    NASA Astrophysics Data System (ADS)

    Krajenbrink, G. J. W.; Ronen, D.; Van Duijvenbooden, W.; Magaritz, M.; Wever, D.

    1988-03-01

    The study compares the quality of groundwater in the water table zone and soil moisture below the root zone, under woodland, with the quality of the regional precipitation. The water quality under forest shows evidence of the effect of atmospheric deposition of acidic components (e.g. SO 2) and ammonia volatilized from land and feed lots. Detailed chemical profiles of the upper meter of groundwater under different plots of forest, at varying distances from cultivated land, were obtained with a multilayer sampler, using the dialysis-cell method. Porous ceramic cups and a vacuum method were used to obtain soil moisture samples at 1.20 m depth under various types of trees, an open spot and arable land, for the period of a year. The investigation took place in the recharge area of a pumping station with mainly mixed forest, downwind of a vast agricultural area with high ammonia volatilization and underlain by an ice-deformed aquifer. Very high NO -3 concentrations were observed in soil moisture and groundwater (up to 21 mg Nl -1) under coniferous forest, especially in the border zone. This raises the question of the dilution capacity of recharge water under woodland in relation to the polluted groundwater under farming land. The buffering capacity of the unsaturated zone varies substantially and locally a low pH (4.5) was observed in groundwater. The large variability of leachate composition on different scales under a forest and the lesser but still significant concentration differences in the groundwater prove the importance of a monitoring system for the actual solute flux into the groundwater.

  16. Ajustement du rechargement et des mecanismes de reactivite des reacteurs CANDU pour les cycles de combustible avances

    NASA Astrophysics Data System (ADS)

    St-Aubin, Emmanuel

    This research project main objectives are to set up and apply a methodology that can determine the potential of advanced thorium-based fuel cycles in CANDU reactors and that is able to adjust reactivity devices, in such a way as to maintain their reference efficiency for these new fuels. In order to select these fuel cycles, a large alternative fuel envelope is submitted to several discriminating criteria. A coarse parametric core modeling, that takes into account standard reactivity devices, is first used to highlight candidates presenting the best economical performances and to eliminate non viable options. Then, for the best candidates, the neutronic modeling is optimized before considering reactivity devices adjustment. For every reactivity device managed by the reactor regulating system, innovative generic optimization methods are used to achieve specific objectives for every fuel cycle, all of them being based on the reference natural uranium cycle behavior. Specific optimization objectives are assessed by simulating advanced fuel cycle for specific operating conditions, including : normal on-power refueling period, spurious reactor trip and fueling machine unavailibility. Unlike the generalized perturbative approach proposed in the OPTEX code, we have successfully implemented a multi-step method able to maximize both the energy extracted from the fuel using an equilibrium refueling optimization, and the reactivity devices adequacy. We also propose new reactivity device supercell models that provides accurate reactor databases for a fraction of the computing cost usually needed using a full model with a similar spatial discretization. Our approach is verified by comparing our simulation results with results published in the literature for the reference fuel cycle. The methodology developed identified advanced fuel cycles, containing up to 60%v. thorium, thereby increasing resources utilization by more than 50% and multiplying the fuel average exit burn-up by a factor of 4.4 when compared with the reference cycle. The reactivity devices were also retained after our optimization processes, requiring only minor modifications to the original design. We determined that a 10%v. heavy water doping of the light water within liquid zone controllers could increase the average exit burnup of the reference cycle by almost 1%, without any adverse consequence to the reactor control. This method is validated through its systematic application to numerous different cases. It demonstrates its capability to achieve very different objectives related to reactivity devices requirements, thus it can be now used for other similar studies.

  17. Echo Meadows Project Winter Artificial Recharge.

    SciTech Connect

    Ziari, Fred

    2002-12-19

    This report discusses the findings of the Echo Meadows Project (BPA Project 2001-015-00). The main purpose of this project is to artificially recharge an alluvial aquifer, WITH water from Umatilla River during the winter high flow period. In turn, this recharged aquifer will discharge an increased flow of cool groundwater back to the river, thereby improving Umatilla River water quality and temperature. A considerable side benefit is that the Umatilla River should improve as a habitat for migration, spanning, and rearing of anadromous and resident fish. The scope of this project is to provide critical baseline information about the Echo Meadows and the associated reach of the Umatilla River. Key elements of information that has been gathered include: (1) Annual and seasonal groundwater levels in the aquifer with an emphasis on the irrigation season, (2) Groundwater hydraulic properties, particularly hydraulic conductivity and specific yield, and (3) Groundwater and Umatilla River water quality including temperature, nutrients and other indicator parameters. One of the major purposes of this data gathering was to develop input to a groundwater model of the area. The purpose of the model is to estimate our ability to recharge this aquifer using water that is only available outside of the irrigation season (December through the end of February) and to estimate the timing of groundwater return flow back to the river. We have found through the data collection and modeling efforts that this reach of the river had historically returned as much as 45 cubic feet per second (cfs) of water to the Umatilla River during the summer and early fall. However, this return flow was reduced to as low as 10 cfs primarily due to reduced quantities of irrigation application, gain in irrigation efficiencies and increased groundwater pumping. Our modeling indicated that it is possible to restore these critical return flows using applied water outside of the irrigation season. We further

  18. Artificial Recharge Coupled with Flood Mitigation in Jeju, Korea

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Koo, M.; Lee, K.; Moon, D.; Barry, J. M.; Park, W.

    2010-12-01

    The primary goal of this study is to develop and apply the artificial recharge system at Han Stream in Jeju Island, Korea, for not only securing sustainable groundwater resources, but also mitigating severe floods occurred due to the global climate changes. Jeju-friendly Aquifer Recharge Technology (J-ART) in this study has been developed by capturing ephemeral stream water with no interference in the environments such as natural recharge or eco-system, storing the flood water in the reservoirs, recharging it through designed borehole after appropriate water treatment, and then making it to be used at down-gradient production wells. For optimal design of J-ART, we conducted injection tests at the monitoring well (MW5) as well as at the planned recharge site during drilling the recharge wells and performed a modeling with the data obtained. Based on the modeling results, the artificial recharge wells were developed with a design of 10-meter spacing between the wells and 35-40 meter depths, which has a capacity of more than 2,500,000 m3 of groundwater resources in a year. Characterizing groundwater flow from recharge area to discharge area should be achieved to assess the efficiency of J-ART. The resistivity logging employed to predict water flow in unsaturated zone during artificial recharge based on the inverse modeling and resistivity change patterns. Stable isotope studies of deuterium and oxygen-18 of surface waters and groundwaters were carried out to interpret mixing and flow in groundwaters impacted by artificial recharge. Transient models were developed to predict the effects of artificial recharge using the hydraulic properties of aquifers, groundwater levels, and meteorological data. Time series changes of water balance after artificial recharge were analyzed, and residence time of the recharged water was also predicted with a certain degree of uncertainty. Keywords: J-ART, Hydrogeological methods, Geophysical survey, Stable isotopes, Groundwater modeling

  19. The relative contributions of summer and cool-season precipitation to groundwater recharge, Spring Mountains, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Winograd, Isaac J.; Riggs, Alan C.; Coplen, Tyler B.

    A comparison of the stable-isotope signatures of spring waters, snow, snowmelt, summer (July thru September) rain, and cool season (October thru June) rain indicates that the high-intensity, short-duration summer convective storms, which contribute approximately a third of the annual precipitation to the Spring Mountains, provide only a small fraction (perhaps 10%) of the recharge to this major upland in southern Nevada, USA. Late spring snowmelt is the principal means of recharging the fractured Paleozoic-age carbonate rocks comprising the central and highest portion of the Spring Mountains. Daily discharge measurements at Peak Spring Canyon Creek during the period 1978-94 show that snowpacks were greatly enhanced during El Niño events. Résumé La comparaison des signatures isotopiques stables des eaux de sources, de neige, de fonte de neige, des pluies d'été (juillet à septembre) et de saison froide (octobre à juin) montre que les précipitations convectives d'été de forte intensité et de courte durée, apportant un tiers des précipitations annuelles reçues par les Monts Spring, ne participent que pour une faible part (10%) à la recharge de cette importante zone d'altitude du sud du Nevada (États-Unis). La fonte tardive de la neige au printemps constitue l'essentiel de la recharge des roches carbonatées fracturées d'âge paléozoïque formant la partie centrale et la plus haute des Monts Spring. Les données journalières de débit sur la rivière du canyon de Peak Spring, entre 1978 et 1994, montrent que les hauteurs de neige ont été plus élevées pendant les événements El Niño. Resumen La comparación entre las marcas isotópicas de aguas de manantiales, nieve, deshielo, lluvias de verano (julio a septiembre) y resto de lluvias (octubre a junio) indican que las tormentas de verano, de corta duración y gran intensidad, las cuales suponen alrededor de un tercio de la precipitación total anual en las Spring Mountains, proporcionan sólo una

  20. Quantifying potential recharge in mantled sinkholes using ERT.

    PubMed

    Schwartz, Benjamin F; Schreiber, Madeline E

    2009-01-01

    Potential recharge through thick soils in mantled sinkholes was quantified using differential electrical resistivity tomography (ERT). Conversion of time series two-dimensional (2D) ERT profiles into 2D volumetric water content profiles using a numerically optimized form of Archie's law allowed us to monitor temporal changes in water content in soil profiles up to 9 m in depth. Combining Penman-Monteith daily potential evapotranspiration (PET) and daily precipitation data with potential recharge calculations for three sinkhole transects indicates that potential recharge occurred only during brief intervals over the study period and ranged from 19% to 31% of cumulative precipitation. Spatial analysis of ERT-derived water content showed that infiltration occurred both on sinkhole flanks and in sinkhole bottoms. Results also demonstrate that mantled sinkholes can act as regions of both rapid and slow recharge. Rapid recharge is likely the result of flow through macropores (such as root casts and thin gravel layers), while slow recharge is the result of unsaturated flow through fine-grained sediments. In addition to developing a new method for quantifying potential recharge at the field scale in unsaturated conditions, we show that mantled sinkholes are an important component of storage in a karst system.

  1. [Effects of reclaimed water recharge on groundwater quality: a review].

    PubMed

    Chen, Wei-Ping; Lü, Si-Dan; Wang, Mei-E; Jiao, Wen-Tao

    2013-05-01

    Reclaimed water recharge to groundwater is an effective way to relieve water resource crisis. However, reclaimed water contains some pollutants such as nitrate, heavy metals, and new type contaminants, and thus, there exists definite environmental risk in the reclaimed water recharge to groundwater. To promote the development of reclaimed water recharge to groundwater and the safe use of reclaimed water in China, this paper analyzed the relevant literatures and practical experiences around the world, and summarized the effects of different reclaimed water recharge modes on the groundwater quality. Surface recharge makes the salt and nitrate contents in groundwater increased but the risk of heavy metals pollution be smaller, whereas well recharge can induce the arsenic release from sedimentary aquifers, which needs to be paid more attention to. New type contaminants are the hotspots in current researches, and their real risks are unknown. Pathogens have less pollution risks on groundwater, but some virus with strong activity can have the risks. Some suggestions were put forward to reduce the risks associated with the reclaimed water recharge to groundwater in China.

  2. Using atmospheric tracers to reduce uncertainty in groundwater recharge areas.

    PubMed

    Starn, J Jeffrey; Bagtzoglou, Amvrossios C; Robbins, Gary A

    2010-01-01

    A Monte Carlo-based approach to assess uncertainty in recharge areas shows that incorporation of atmospheric tracer observations (in this case, tritium concentration) and prior information on model parameters leads to more precise predictions of recharge areas. Variance-covariance matrices, from model calibration and calculation of sensitivities, were used to generate parameter sets that account for parameter correlation and uncertainty. Constraining parameter sets to those that met acceptance criteria, which included a standard error criterion, did not appear to bias model results. Although the addition of atmospheric tracer observations and prior information produced similar changes in the extent of predicted recharge areas, prior information had the effect of increasing probabilities within the recharge area to a greater extent than atmospheric tracer observations. Uncertainty in the recharge area propagates into predictions that directly affect water quality, such as land cover in the recharge area associated with a well and the residence time associated with the well. Assessments of well vulnerability that depend on these factors should include an assessment of model parameter uncertainty. A formal simulation of parameter uncertainty can be used to delineate probabilistic recharge areas, and the results can be expressed in ways that can be useful to water-resource managers. Although no one model is the correct model, the results of multiple models can be evaluated in terms of the decision being made and the probability of a given outcome from each model.

  3. Stable isotope tracers: natural and anthropogenic recharge, Orange County, California

    NASA Astrophysics Data System (ADS)

    Williams, Alan E.

    1997-12-01

    Stable isotopic techniques have been utilized to locate occurrences and trace movements of a variety of naturally and anthropogenically recharged waters in aquifers of Orange County, California. This basin is of particular interest not only because it provides the dominant water supply for the two million residents of this well-populated county, but also because it is representative of a common arid environment where natural recharge is dominated by distant, high-elevation precipitation transported by a major river. Such arid basins are particularly sensitive to climatic and anthropogenic disturbance of their recharge and their subsurface hydrology. In order to identify distinctive waters, oxygen and hydrogen stable isotope ratios from Orange County wells have been compared with a regional database including an array of surface water samples representative of watershed runoff. Four distinctive subsurface water types can be resolved. Waters of "local" rainfall and imported, "Colorado" River aqueduct origins are easily distinguished from dominant, "native" Santa Ana river compositions by use of hydrogen and oxygen stable isotope analysis. Recent human interference with Santa Ana river flow and recharge is also marginally resolvable by isotopic techniques. Distinguishable isotopic signatures of "recent" Santa Ana recharge appear to be due to evaporative loss, perhaps during storage in the Prado Reservoir or in percolation ponds, prior to recharge into Orange County aquifers. Characterization of traceable isotopic signatures of distinct natural and anthropogenic recharge components provides a major advance towards use of such techniques for developing a well constrained, three-dimensional hydrologic model for this complex basin.

  4. Geostatistical estimates of future recharge for the Death Valley region

    SciTech Connect

    Hevesi, J.A.; Flint, A.L.

    1998-12-01

    Spatially distributed estimates of regional ground water recharge rates under both current and potential future climates are needed to evaluate a potential geologic repository for high-level nuclear waste at Yucca Mountain, Nevada, which is located within the Death Valley ground-water region (DVGWR). Determining the spatial distribution of recharge is important for regional saturated-zone ground-water flow models. In the southern Nevada region, the Maxey-Eakin method has been used for estimating recharge based on average annual precipitation. Although this method does not directly account for a variety of location-specific factors which control recharge (such as bedrock permeability, soil cover, and net radiation), precipitation is the primary factor that controls in the region. Estimates of recharge obtained by using the Maxey-Eakin method are comparable to estimates of recharge obtained by using chloride balance studies. The authors consider the Maxey-Eakin approach as a relatively simple method of obtaining preliminary estimates of recharge on a regional scale.

  5. Structure and U-Pb zircon geochronology of an Alpine nappe stack telescoped by extensional detachment faulting (Kulidzhik area, Eastern Rhodopes, Bulgaria)

    NASA Astrophysics Data System (ADS)

    Georgiev, Neven; Froitzheim, Nikolaus; Cherneva, Zlatka; Frei, Dirk; Grozdev, Valentin; Jahn-Awe, Silke; Nagel, Thorsten J.

    2016-10-01

    The Rhodope Metamorphic Complex is a stack of allochthons assembled during obduction, subduction, and collision processes from Jurassic to Paleogene and overprinted by extensional detachment faults since Middle Eocene. In the study area, the following nappes occur in superposition (from base to top): an orthogneiss-dominated unit (Unit I), garnet-bearing schist with amphibolite and serpentinite lenses (Unit II), greenschist, phyllite, and calcschist with reported Jurassic microfossils (Unit III), and muscovite-rich orthogneiss (Unit IV). U-Pb dating of zircons from a K-feldspar augengneiss (Unit I) yielded a protolith age of ca. 300 Ma. Garnet-bearing metasediment from Unit II yielded an age spectrum with distinct populations between 310 and 250 Ma (detrital), ca. 150 Ma, and ca. 69 Ma (the last two of high-grade metamorphic origin). An orthogneiss from Unit IV yielded a wide spectrum of ages. The youngest population gives a concordia age of 581 ± 5 Ma, interpreted as the age of the granitic protolith. Unit I represents the Lower Allochthon (Byala Reka-Kechros Dome), Unit II the Upper Allochthon (Krumovitsa-Kimi Unit), Unit III the Uppermost Allochthon (Circum-Rhodope Belt), and Unit IV a still higher, far-travelled unit of unknown provenance. Telescoping of the entire Rhodope nappe stack to a thickness of only a few 100 m is due to Late Eocene north directed extensional shearing along the newly defined Kulidzhik Detachment which is part of a major detachment system along the northern border of the Rhodopes. Older top-to-the south mylonites in Unit I indicate that Tertiary extension evolved from asymmetric (top-to-the-south) to symmetric (top-to-the-south and top-to-the-north), bivergent unroofing.

  6. From nappe stacking to out-of-sequence postcollisional deformations: Cretaceous to Quaternary exhumation history of the SE Carpathians assessed by low-temperature thermochronology

    NASA Astrophysics Data System (ADS)

    Merten, S.; Matenco, L.; Foeken, J. P. T.; Stuart, F. M.; Andriessen, P. A. M.

    2010-06-01

    Apatite fission track (AFT) and (U-Th)/He (AHe) thermochronology have been combined to constrain the exhumation history of the SE Carpathians. Cooling ages generally decrease from Cretaceous for the internal basement nappes (AFT ages), to Miocene-Quaternary (AFT and AHe, respectively) for the external sedimentary wedge. The AFT and AHe data show a Paleogene age cluster, which confirms a suspected but never demonstrated tectonic event. The new data furthermore suggest that the SE Carpathians have been affected by a middle Miocene exhumation phase related to continental collision, which occurred at rates of ˜0.8 mm/yr, similar to the one previously inferred for the East Carpathians. The SE Carpathian tectonic evolution, however, is overprinted by two younger exhumation events in the Pliocene-Pleistocene. The first exhumation phase (latest Miocene-early Pliocene) occurred at high exhumation rates (˜1.7 mm/yr) and is interpreted as a tectonic event and/or associated with a sea level drop in the Paratethys basins during the Messinian low stand. The youngest recorded tectonic phase suggests rapid Pleistocene exhumation (˜1.6 mm/yr) and is interpreted to represent crustal-scale shortening different in mechanics from collisional processes. The data suggest that the SE Carpathians did not develop as a typical double-vergent orogenic wedge; instead, exhumation was related to a foreland-vergent sequence of nappe stacking during collision and was subsequently followed by a large out-of-sequence shortening event truncating the already locked collisional boundary.

  7. Effects of artificial recharge on the Ogallala aquifer, Texas

    USGS Publications Warehouse

    Brown, Richmond Flint; Keys, W.S.

    1985-01-01

    Four recharge tests were conducted by injecting water from playa lakes through wells into the Ogallala Formation. Injection was by gravity flow and by pumping under pressure. At one site, 34-acre feet of water was injected by gravity and produced a significant increase in yield of the well. At a second site, gravity injection of only 0.58 acre-foot caused a significant decrease in permeability due to plugging by suspended sediment. At two other sites, injection by pumping 6 and 14 acre-feet respectively, resulted in discharge of water at the surface and in perching of water above the water table. Differences in success of recharge were largely due to aquifer lithology and, therefore, the type of permeability; the concentration of suspended solids in the recharge water; and the injection technique. The injection technique can be controlled and the concentration of suspended solids can be minimized by treatment, but the site for well recharge will accept water most rapidly if it is selected on the basis of a favorable geohydrologic environment. Geophysical logs were used to study the effect of aquifer lithology on recharge and to understand the movement of injected water. Temperature logs were particularly useful in tracing the movement of recharged water. Natural-gamma, gamma-gamma, and neutron logs provided important data on lithology and porosity in the aquifer and changes in porosity and water distribution resulting from recharge. Effective recharge of the Ogallala Formation, using water from playa lakes, is possible where geohydrologic conditions are favorable and the recharge system is properly constructed.

  8. Des ballons pour demain

    NASA Astrophysics Data System (ADS)

    Régipa, R.

    A partir d'une théorie sur la détermination des formes et des contraintes globales d'un ballon de révolution, ou s'en rapprochant, une nouvelle famille de ballons a été définie. Les ballons actuels, dits de ``forme naturelle'', sont calculés en général pour une tension circonférencielle nulle. Ainsi, pour une mission donnée, la tension longitudinale et la forme de l'enveloppe sont strictement imposées. Les ballons de la nouvelle génération sont globalement cylindriques et leurs pôles sont réunis par un câble axial, chargé de transmettre une partie des efforts depuis le crochet (pôle inférieur), directement au pôle supérieur. De plus, la zone latérale cylindrique est soumise à un faible champ de tensions circonférencielles. Ainsi, deux paramètres permettent de faire évoluer la distribution des tensions et la forme de l'enveloppe: - la tension du câble de liaison entre pôles (ou la longueur de ce câble) - la tension circonférencielle moyenne désirée (ou le rayon du ballon). On peut donc calculer et réaliser: - soit des ballons de forme adaptée, comme les ballons à fond plat pour le bon fonctionnement des montgolfières infrarouge (projet MIR); - soit des ballons optimisés pour une bonne répartition des contraintes et une meilleure utilisation des matériaux d'enveloppe, pour l'ensemble des programmes stratosphériques. Il s'ensuit une économie sensible des coûts de fabrication, une fiabilité accrue du fonctionnement de ces ballons et une rendement opérationnel bien supérieur, permettant entre autres, d'envisager des vols à très haute altitude en matériaux très légers.

  9. Recharge and discharge calculations to characterize the groundwater hydrologic balance

    SciTech Connect

    Liddle, R.G.

    1998-12-31

    Several methods are presented to quantify the ground water component of the hydrologic balance; including (1) hydrograph separation techniques, (2) water budget calculations, (3) spoil discharge techniques, and (4) underground mine inflow studies. Stream hydrograph analysis was used to calculate natural groundwater recharge and discharge rates. Yearly continuous discharge hydrographs were obtained for 16 watersheds in the Cumberland Plateau area of Tennessee. Baseflow was separated from storm runoff using computerized hydrograph analysis techniques developed by the USGS. The programs RECESS, RORA, and PART were used to develop master recession curves, calculate ground water recharge, and ground water discharge respectively. Station records ranged from 1 year of data to 60 years of data with areas of 0.67 to 402 square miles. Calculated recharge ranged from 7 to 28 inches of precipitation while ground water discharge ranged from 6 to 25 inches. Baseflow ranged from 36 to 69% of total flow. For sites with more than 4 years of data the median recharge was 20 inches/year and the 95% confidence interval for the median was 16.4 to 23.8 inches of recharge. Water budget calculations were also developed independently by a mining company in southern Tennessee. Results showed about 19 inches of recharge is available on a yearly basis. A third method used spoil water discharge measurements to calculate average recharge rate to the mine. Results showed 21.5 inches of recharge for this relatively flat area strip mine. In a further analysis it was shown that premining soil recharge rates of 19 inches consisted of about 17 inches of interflow and 2 inches of deep aquifer recharge while postmining recharge to the spoils had almost no interflow component. OSM also evaluated underground mine inflow data from northeast Tennessee and southeast Kentucky. This empirical data showed from 0.38 to 1.26 gallons per minute discharge per unit acreage of underground workings. This is the

  10. Improved zinc electrode and rechargeable zinc-air battery

    DOEpatents

    Ross, P.N. Jr.

    1988-06-21

    The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

  11. ENGINEERING ECONOMIC ANALYSIS OF A PROGRAM FOR ARTIFICIAL GROUNDWATER RECHARGE.

    USGS Publications Warehouse

    Reichard, Eric G.; Bredehoeft, John D.

    1984-01-01

    This study describes and demonstrates two alternate methods for evaluating the relative costs and benefits of artificial groundwater recharge using percolation ponds. The first analysis considers the benefits to be the reduction of pumping lifts and land subsidence; the second considers benefits as the alternative costs of a comparable surface delivery system. Example computations are carried out for an existing artificial recharge program in Santa Clara Valley in California. A computer groundwater model is used to estimate both the average long term and the drought period effects of artificial recharge in the study area. Results indicate that the costs of artificial recharge are considerably smaller than the alternative costs of an equivalent surface system. Refs.

  12. Bipolar rechargeable lithium battery for high power applications

    NASA Technical Reports Server (NTRS)

    Hossain, Sohrab; Kozlowski, G.; Goebel, F.

    1993-01-01

    Viewgraphs of a discussion on bipolar rechargeable lithium battery for high power applications are presented. Topics covered include cell chemistry, electrolytes, reaction mechanisms, cycling behavior, cycle life, and cell assembly.

  13. Hydrogeological Methods for Assessing Feasibility of Artificial Recharge

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Koo, M.; Lee, K.; Moon, D.; Barry, J. M.

    2009-12-01

    This study presents the hydrogeological methods to assess the feasibility of artificial recharge in Jeju Island, Korea for securing both sustainable groundwater resources and severe floods. Jeju-friendly Aquifer Recharge Technology (J-ART) in this study is developing by capturing ephemeral stream water with no interference in the environments such as natural recharge or eco-system, storing the flood water in the reservoirs, recharging it through designed borehole after appropriate water treatment, and then making it to be used at down-gradient production wells. Many hydrogeological methods, including physico-chemical surface water and groundwater monitoring, geophysical survey, stable isotope analysis, and groundwater modeling have been employed to predict and assess the artificially recharged surface waters flow and circulation between recharge area and discharge area. In the study of physico-chemical water monitoring survey, the analyses of surface water level and velocity, of water qualities including turbidity, and of suspended soil settling velocity were performed. For understanding subsurface hydrogeologic characteristics the injection test was executed and the results are 118-336 m2/day of transmissivity and 4,367-11,032 m3/day of the maximum intake water capacity. Characterizing groundwater flow from recharge area to discharge area should be achieved to assess the efficiency of J-ART. The resistivity logging was carried out to predict water flow in unsaturated zone during artificial recharge based on the inverse modeling and resistivity change patterns. Stable isotopes of deuterium and oxygen-18 of surface waters and groundwaters have been determined to interpret mixing and flow in groundwaters impacted by artificial recharge. A numerical model simulating groundwater flow and heat transport to assess feasibility of artificial recharge has been developed using the hydraulic properties of aquifers, groundwater levels, borehole temperatures, and meteorological

  14. Cryogenic Transport of High-Pressure-System Recharge Gas

    NASA Technical Reports Server (NTRS)

    Ungar, Eugene K,; Ruemmele, Warren P.; Bohannon, Carl

    2010-01-01

    A method of relatively safe, compact, efficient recharging of a high-pressure room-temperature gas supply has been proposed. In this method, the gas would be liquefied at the source for transport as a cryogenic fluid at or slightly above atmospheric pressure. Upon reaching the destination, a simple heating/expansion process would be used to (1) convert the transported cryogenic fluid to the room-temperature, high-pressure gaseous form in which it is intended to be utilized and (2) transfer the resulting gas to the storage tank of the system to be recharged. In conventional practice for recharging high-pressure-gas systems, gases are transported at room temperature in high-pressure tanks. For recharging a given system to a specified pressure, a transport tank must contain the recharge gas at a much higher pressure. At the destination, the transport tank is connected to the system storage tank to be recharged, and the pressures in the transport tank and the system storage tank are allowed to equalize. One major disadvantage of the conventional approach is that the high transport pressure poses a hazard. Another disadvantage is the waste of a significant amount of recharge gas. Because the transport tank is disconnected from the system storage tank when it is at the specified system recharge pressure, the transport tank still contains a significant amount of recharge gas (typically on the order of half of the amount transported) that cannot be used. In the proposed method, the cryogenic fluid would be transported in a suitably thermally insulated tank that would be capable of withstanding the recharge pressure of the destination tank. The tank would be equipped with quick-disconnect fluid-transfer fittings and with a low-power electric heater (which would not be used during transport). In preparation for transport, a relief valve would be attached via one of the quick-disconnect fittings (see figure). During transport, the interior of the tank would be kept at a near

  15. Wearable textile battery rechargeable by solar energy.

    PubMed

    Lee, Yong-Hee; Kim, Joo-Seong; Noh, Jonghyeon; Lee, Inhwa; Kim, Hyeong Jun; Choi, Sunghun; Seo, Jeongmin; Jeon, Seokwoo; Kim, Taek-Soo; Lee, Jung-Yong; Choi, Jang Wook

    2013-01-01

    Wearable electronics represent a significant paradigm shift in consumer electronics since they eliminate the necessity for separate carriage of devices. In particular, integration of flexible electronic devices with clothes, glasses, watches, and skin will bring new opportunities beyond what can be imagined by current inflexible counterparts. Although considerable progresses have been seen for wearable electronics, lithium rechargeable batteries, the power sources of the devices, do not keep pace with such progresses due to tenuous mechanical stabilities, causing them to remain as the limiting elements in the entire technology. Herein, we revisit the key components of the battery (current collector, binder, and separator) and replace them with the materials that support robust mechanical endurance of the battery. The final full-cells in the forms of clothes and watchstraps exhibited comparable electrochemical performance to those of conventional metal foil-based cells even under severe folding-unfolding motions simulating actual wearing conditions. Furthermore, the wearable textile battery was integrated with flexible and lightweight solar cells on the battery pouch to enable convenient solar-charging capabilities.

  16. Oxocarbon Salts for Fast Rechargeable Batteries.

    PubMed

    Zhao, Qing; Wang, Jianbin; Lu, Yong; Li, Yixin; Liang, Guangxin; Chen, Jun

    2016-09-26

    Oxocarbon salts (M2 (CO)n ) prepared through one-pot proton exchange reactions with different metal ions (M=Li, Na, K) and frameworks (n=4, 5, 6) have been rationally designed and used as electrodes in rechargeable Li, Na, and K-ion batteries. The results show that M2 (CO)5 /M2 (CO)6 salts can insert two or four metal ions reversibly, while M2 (CO)4 shows less electrochemical activity. Especially, we discover that the K2 C6 O6 electrode enables ultrafast potassium-ion insertion/extraction with 212 mA h g(-1) at 0.2 C and 164 mA h g(-1) at 10 C. This behavior can be ascribed to the natural semiconductor property of K2 C6 O6 with a narrow band gap close to 0.9 eV, the high ionic conductivity of the K-ion electrolyte, and the facilitated K-ion diffusion process. Moreover, a first example of a K-ion battery with a rocking-chair reaction mechanism of K2 C6 O6 as cathode and K4 C6 O6 as anode is introduced, displaying an operation voltage of 1.1 V and an energy density of 35 Wh kg(-1) . This work provides an interesting strategy for constructing rapid K-ion batteries with renewable and abundant potassium materials.

  17. Oxocarbon Salts for Fast Rechargeable Batteries.

    PubMed

    Zhao, Qing; Wang, Jianbin; Lu, Yong; Li, Yixin; Liang, Guangxin; Chen, Jun

    2016-09-26

    Oxocarbon salts (M2 (CO)n ) prepared through one-pot proton exchange reactions with different metal ions (M=Li, Na, K) and frameworks (n=4, 5, 6) have been rationally designed and used as electrodes in rechargeable Li, Na, and K-ion batteries. The results show that M2 (CO)5 /M2 (CO)6 salts can insert two or four metal ions reversibly, while M2 (CO)4 shows less electrochemical activity. Especially, we discover that the K2 C6 O6 electrode enables ultrafast potassium-ion insertion/extraction with 212 mA h g(-1) at 0.2 C and 164 mA h g(-1) at 10 C. This behavior can be ascribed to the natural semiconductor property of K2 C6 O6 with a narrow band gap close to 0.9 eV, the high ionic conductivity of the K-ion electrolyte, and the facilitated K-ion diffusion process. Moreover, a first example of a K-ion battery with a rocking-chair reaction mechanism of K2 C6 O6 as cathode and K4 C6 O6 as anode is introduced, displaying an operation voltage of 1.1 V and an energy density of 35 Wh kg(-1) . This work provides an interesting strategy for constructing rapid K-ion batteries with renewable and abundant potassium materials. PMID:27608329

  18. Recharge to the North Richland well field

    SciTech Connect

    Law, A.G.

    1989-07-01

    The investigation was based on a preliminary ground-water flow model of the 1100 Area. Because few local data were available for this effort, an existing regional ground-water flow model of the Hanford Site was applied, which is based on the Variable Thickness Transient (VTT) ground-water flow code (Kipp et al., 1976). A submodel of the Hanford Site model was developed based on the VTT code. An independent model consisting of a simple representation of the local conditions in the vicinity of the North Richland well field was also used in the investigation. This model, based on the MODFLOW code (McDonald and Harbaugh, 1984), was used in a series of transient simulations to examine dynamic aspects of the well field/recharge basin. Results from this simple model also provide an independent, qualitative check of results produced with the 1100 Area model based on the VTT code. This report summarizes the 1100 Area modeling investigation, including the approach used to generate results for the regional and 1100 Area VTT models, the approach used in the transient MODFLOW model, results from some initial steady-state and transient simulations with the submodel and the MODFLOW models, and resulting conclusions and recommendations. Because local data were lacking to develop and calibrate the models, the investigation described in this report can best be described as a ''sensitivity analysis'' of ground-water flow in the 1100 Area. 4 refs., 10 figs., 2 tabs.

  19. Thin-film Rechargeable Lithium Batteries

    DOE R&D Accomplishments Database

    Bates, J. B.; Gruzalski, G. R.; Dudney, N. J.; Luck, C. F.; Yu, X.

    1993-11-01

    Rechargeable thin films batteries with lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have been fabricated and characterized. The cathodes include TiS{sub 2}, the {omega} phase of V{sub 2}O{sub 5}, and the cubic spinel Li{sub x}Mn{sub 2}O{sub 4} with open circuit voltages at full charge of about 2.5 V, 3.7 V, and 4.2 V, respectively. The development of these robust cells, which can be cycled thousands of times, was possible because of the stability of the amorphous lithium electrolyte, lithium phosphorus oxynitride. This material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46} and a conductivity at 25 C of 2 {mu}S/cm. Thin film cells have been cycled at 100% depth of discharge using current densities of 2 to 100 {mu}A/cm{sup 2}. The polarization resistance of the cells is due to the slow insertion rate of Li{sup +} ions into the cathode. Chemical diffusion coefficients for Li{sup +} ions in the three types of cathodes have been estimated from the analysis of ac impedance measurements.

  20. Thermal and Electrical Recharging of Sodium/Sulfur Cells

    NASA Technical Reports Server (NTRS)

    Richter, Robert

    1987-01-01

    Efficiency as high as 60 percent achieved. Proposed thermal and electrical recharging scheme expected to increase overall energy efficiency of battery of sodium/sulfur cells (beta cells). Takes advantage of peculiarity in chemical kinetics of recharge portion of operating cycle to give thermal assist to electrically driven chemical reactions. Future application include portable power supplies and energy storage in commercial power systems during offpeak periods.

  1. Zinc electrode and rechargeable zinc-air battery

    SciTech Connect

    Ross, P.N. Jr.

    1989-06-27

    This patent describes an improved zinc electrode for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed.

  2. Sources of uncertainty in climate change impacts on groundwater recharge

    NASA Astrophysics Data System (ADS)

    Holman, I. P.

    2007-12-01

    This paper assesses the significance of the many sources of uncertainty in future groundwater recharge estimation, based on lessons learnt from an integrated approach to assessing the regional impacts of climate and socio-economic change on groundwater recharge in East Anglia, UK. Many factors affect simulations of future groundwater recharge including changed precipitation and temperature regimes, coastal flooding, urbanization, woodland establishment, and changes in cropping, rotations and management practices. Stochastic modelling of potential recharge showed median annual recharge decreasing under a High emissions future from 75 mm (1961-90) to 56 mm in the 2020s and 45 mm in the 2050s. However, the median values for individual simulations ranged from 46-75 mm (2020s) and 30-71 mm (2050s) highlighting a decreasing but uncertain trend. The impacts of (and uncertainty in) the climate scenarios are generally regionally more important than those of the socio-economic scenarios. However, locally, the impacts of the socio-economic scenarios can be significant, especially where there are large increases in urbanization, agricultural land cover, bioenergy production, or agricultural management practices. For example, management of soil conditions can increase potential groundwater recharge by around 5 %, but poor management can further reduce potential recharge by up to 15 %. The paper will demonstrate that to focus on the direct impacts of climate change is to neglect the potentially important role of policy, societal values and economic processes in shaping the landscape above aquifers. If the likely consequences of future changes of groundwater recharge, resulting from both climate and socio-economic change, are to be assessed, hydrogeologists must increasingly work with researchers from other disciplines, such as socio-economists, agricultural modellers and soil scientists

  3. Ground water recharge and flow characterization using multiple isotopes.

    PubMed

    Chowdhury, Ali H; Uliana, Matthew; Wade, Shirley

    2008-01-01

    Stable isotopes of delta(18)O, delta(2)H, and (13)C, radiogenic isotopes of (14)C and (3)H, and ground water chemical compositions were used to distinguish ground water, recharge areas, and possible recharge processes in an arid zone, fault-bounded alluvial aquifer. Recharge mainly occurs through exposed stream channel beds as opposed to subsurface inflow along mountain fronts. This recharge distribution pattern may also occur in other fault-bounded aquifers, with important implications for conceptualization of ground water flow systems, development of ground water models, and ground water resource management. Ground water along the mountain front near the basin margins contains low delta(18)O, (14)C (percent modern carbon [pmC]), and (3)H (tritium units [TU]), suggesting older recharge. In addition, water levels lie at greater depths, and basin-bounding faults that locally act as a flow barrier may further reduce subsurface inflow into the aquifer along the mountain front. Chemical differences in ground water composition, attributed to varying aquifer mineralogy and recharge processes, further discriminate the basin-margin and the basin-center water. Direct recharge through the indurated sandstones and mudstones in the basin center is minimal. Modern recharge in the aquifer is mainly through the broad, exposed stream channel beds containing coarse sand and gravel where ground water contains higher delta(18)O, (14)C (pmC), and (3)H (TU). Spatial differences in delta(18)O, (14)C (pmC), and (3)H (TU) and occurrences of extensive mudstones in the basin center suggest sluggish ground water movement, including local compartmentalization of the flow system.

  4. Investigation of artificial recharge of aquifers in Nebraska

    USGS Publications Warehouse

    Lichtler, William F.; Stannard, David I.; Kouma, Edwin

    1980-01-01

    Progressive declines of ground-water levels in some areas of Nebraska prompted this investigation into the technical feasibility of recharging aquifers through wells, impoundments, pits, and canals. Information gained from a literature search and from preliminary tests was used to design several artificial-recharge experiments in Nebraska from 1977 to 1979. In well experiments, 0.46 billion gallons of water from an aquifer recharged by the Platte River was transported by pipeline and injected through a well into a sand and gravel aquifer near Aurora. Recharge was at about 730 gallons per minute during tests of 6- and 8-months duration. No evidence of clogging of the aquifer due to chemical reactions, air entrainment, or bacteria was detected in either test. In the 6-month test, evidence of clogging due to fine sediment in the recharge water was detected; however, analysis of this test indicated that recharge could have continued for several years before rehabilitation would have become necessary. Results of the 8-month test confirmed results of the earlier test until casing failure in the supply well and subsequent sediment deposition in the recharge well caused rapid water-level rise in the recharge well. In surface-spreading experiments, maximum infiltration rates from 24-foot-diameter ring infiltrometers near Aurora and Tryon were 0.4 and 11 feet per day, respectively. Results indicate that large-scale surface spreading is feasible only where low-permeability layers are absent in the subsurface. Infiltration rates from reuse pits ranged from 0.01 to 1.6 feet per day, indicating highly variable subsurface permeability. Flow measurements in an irrigation canal near Farwell indicate an infiltration rate of 0.37 feet per day. (USGS)

  5. Rechargeable Magnesium Batteries: Low-Cost Rechargeable Magnesium Batteries with High Energy Density

    SciTech Connect

    2010-10-01

    BEEST Project: Pellion Technologies is developing rechargeable magnesium batteries that would enable an EV to travel 3 times farther than it could using Li-ion batteries. Prototype magnesium batteries demonstrate excellent electrochemical behavior; delivering thousands of charge cycles with very little fade. Nevertheless, these prototypes have always stored too little energy to be commercially viable. Pellion Technologies is working to overcome this challenge by rapidly screening potential storage materials using proprietary, high-throughput computer models. To date, 12,000 materials have been identified and analyzed. The resulting best materials have been electrochemically tested, yielding several very promising candidates.

  6. Seasonal variation in natural recharge of coastal aquifers

    NASA Astrophysics Data System (ADS)

    Mollema, Pauline N.; Antonellini, Marco

    2013-06-01

    Many coastal zones around the world have irregular precipitation throughout the year. This results in discontinuous natural recharge of coastal aquifers, which affects the size of freshwater lenses present in sandy deposits. Temperature data for the period 1960-1990 from LocClim (local climate estimator) and those obtained from the Intergovernmental Panel on Climate Change (IPCC) SRES A1b scenario for 2070-2100, have been used to calculate the potential evapotranspiration with the Thornthwaite method. Potential recharge (difference between precipitation and potential evapotranspiration) was defined at 12 locations: Ameland (The Netherlands), Auckland and Wellington (New Zealand); Hong Kong (China); Ravenna (Italy), Mekong (Vietnam), Mumbai (India), New Jersey (USA), Nile Delta (Egypt), Kobe and Tokyo (Japan), and Singapore. The influence of variable/discontinuous recharge on the size of freshwater lenses was simulated with the SEAWAT model. The discrepancy between models with continuous and with discontinuous recharge is relatively small in areas where the total annual recharge is low (258-616 mm/year); but in places with Monsoon-dominated climate (e.g. Mumbai, with recharge up to 1,686 mm/year), the difference in freshwater-lens thickness between the discontinuous and the continuous model is larger (up to 5 m) and thus important to consider in numerical models that estimate freshwater availability.

  7. Estimating aquifer channel recharge using optical data interpretation.

    PubMed

    Walter, Gary R; Necsoiu, Marius; McGinnis, Ronald

    2012-01-01

    Recharge through intermittent and ephemeral stream channels is believed to be a primary aquifer recharge process in arid and semiarid environments. The intermittent nature of precipitation and flow events in these channels, and their often remote locations, makes direct flow and loss measurements difficult and expensive. Airborne and satellite optical images were interpreted to evaluate aquifer recharge due to stream losses on the Frio River in south-central Texas. Losses in the Frio River are believed to be a major contributor of recharge to the Edwards Aquifer. The results of this work indicate that interpretation of readily available remote sensing optical images can offer important insights into the spatial distribution of aquifer recharge from losing streams. In cases where upstream gauging data are available, simple visual analysis of the length of the flowing reach downstream from the gauging station can be used to estimate channel losses. In the case of the Frio River, the rate of channel loss estimated from the length of the flowing reach at low flows was about half of the loss rate calculated from in-stream gain-loss measurements. Analysis based on water-surface width and channel slope indicated that losses were mainly in a reach downstream of the mapped recharge zone. The analysis based on water-surface width, however, did not indicate that this method could yield accurate estimates of actual flow in pool and riffle streams, such as the Frio River and similar rivers draining the Edwards Plateau.

  8. Sedimentary Origins Of The Block-In-Matrix Fabric Of A Mélange Between Coherent Nappes Of A Subduction Complex: Localization Of The Paleosubduction Megathrust Along The Upper Mélange Contact

    NASA Astrophysics Data System (ADS)

    Wakabayashi, J.

    2011-12-01

    The Franciscan subduction complex of California comprises coherent nappes and intervening mélanges. The difference in metamorphic grade and/or accretionary age of adjacent coherent nappes suggests localization of paleosubduction megathrust horizons between them. One of the best examples of a mélange between coherent nappes crops out in an inactive quarry in El Cerrito in the eastern San Francisco Bay area. The upper coherent nappe consists of foliated, jadeite-bearing, blueschist facies metagraywacke, whereas the lower coherent nappe comprises prehnite-pumpellyite facies graywacke with little or no penetrative fabric makes. Detrital zircon geochronology indicates maximum depositional ages of 102 and 100 Ma, respectively, for these units. The foliation or bedding of the graywackes and their contacts strike northwest and dip northeast. C-s fabrics, shear bands, and asymmetric porphyroclasts show a consistent tops-to-the-southwest shear sense in the upper coherent unit, and this fabric developed with syntectonic growth of glaucophane, lawsonite, and jadeite. The intervening mélange has a matrix made up primarily of dark gray shale, with blocks of mostly graywacke, chert, and basalt. The mélange consists of mostly or entirely prehnite-pumpellyite facies material except for the upper 5-10 meters that features metamorphic growth of lawsonite, glaucophane, and jadeite. Thus, the metamorphic contrast between the two nappes, equivalent to at least 10 km in differential burial depth and greater amount of fault displacement, occurs within this narrow zone. The upper half of the mélange (~50 meters of structural thickness) exhibits a pronounced foliation oriented parallel to the bounding contacts. The foliation deflects into shear bands and c-surfaces and this fabric shows a consistent tops-to-the-southwest shear sense. Strain appears to increase structurally upward within the mélange. The structurally lowest part of the mélange displays virtually no strain, with

  9. Soil Water Balance and Recharge Monitoring at the Hanford Site – FY 2010 Status Report

    SciTech Connect

    Fayer, Michael J.; Saunders, Danielle L.; Herrington, Ricky S.; Felmy, Diana

    2010-10-27

    This report summarizes the recharge data collected in FY 2010 at five locations on the Hanford Site in southeastern Washington State. Average monthly precipitation and temperature conditions in FY 2010 were near normal and did not present an opportunity for increased recharge. The recharge monitoring data confirmed those conditions, showing normal behavior in water content, matric head, and recharge rates. Also provided in this report is a strategy for recharge estimation for the next 5 years.

  10. Design and simulation of lithium rechargeable batteries

    SciTech Connect

    Doyle, C.M.

    1995-08-01

    Lithium -based rechargeable batteries that utilize insertion electrodes are being considered for electric-vehicle applications because of their high energy density and inherent reversibility. General mathematical models are developed that apply to a wide range of lithium-based systems, including the recently commercialized lithium-ion cell. The modeling approach is macroscopic, using porous electrode theory to treat the composite insertion electrodes and concentrated solution theory to describe the transport processes in the solution phase. The insertion process itself is treated with a charge-transfer process at the surface obeying Butler-Volmer kinetics, followed by diffusion of the lithium ion into the host structure. These models are used to explore the phenomena that occur inside of lithium cells under conditions of discharge, charge, and during periods of relaxation. Also, in order to understand the phenomena that limit the high-rate discharge of these systems, we focus on the modeling of a particular system with well-characterized material properties and system parameters. The system chosen is a lithium-ion cell produced by Bellcore in Red Bank, NJ, consisting of a lithium-carbon negative electrode, a plasticized polymer electrolyte, and a lithium-manganese-oxide spinel positive electrode. This battery is being marketed for consumer electronic applications. The system is characterized experimentally in terms of its transport and thermodynamic properties, followed by detailed comparisons of simulation results with experimental discharge curves. Next, the optimization of this system for particular applications is explored based on Ragone plots of the specific energy versus average specific power provided by various designs.

  11. Arsenic release during managed aquifer recharge (MAR)

    NASA Astrophysics Data System (ADS)

    Pichler, T.; Lazareva, O.; Druschel, G.

    2013-12-01

    The mobilization and addition of geogenic trace metals to groundwater is typically caused by anthropogenic perturbations of the physicochemical conditions in the aquifer. This can add dangerously high levels of toxins to groundwater, thus compromising its use as a source of drinking water. In several regions world-wide, aquifer storage and recovery (ASR), a form of managed aquifer recharge (MAR), faces the problem of arsenic release due to the injection of oxygenated storage water. To better understand this process we coupled geochemical reactive transport modeling to bench-scale leaching experiments to investigate and verify the mobilization of geogenic arsenic (As) under a range of redox conditions from an arsenic-rich pyrite bearing limestone aquifer in Central Florida. Modeling and experimental observations showed similar results and confirmed the following: (1) native groundwater and aquifer matrix, including pyrite, were in chemical equilibrium, thus preventing the release of As due to pyrite dissolution under ambient conditions; (2) mixing of oxygen-rich surface water with oxygen-depleted native groundwater changed the redox conditions and promoted the dissolution of pyrite, and (3) the behavior of As along a flow path was controlled by a complex series of interconnected reactions. This included the oxidative dissolution of pyrite and simultaneous sorption of As onto neo-formed hydrous ferric oxides (HFO), followed by the reductive dissolution of HFO and secondary release of adsorbed As under reducing conditions. Arsenic contamination of drinking water in these systems is thus controlled by the re-equilibration of the system to more reducing conditions rather than a purely oxidative process.

  12. Oxygen electrodes for rechargeable alkaline fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.

    1989-01-01

    Electrocatalysts and supports for the positive electrode of moderate temperature single-unit rechargeable alkaline fuel cells are being investigated and developed. Candidate support materials were drawn from transition metal carbides, borides, nitrides and oxides which have high conductivity (greater than 1 ohm/cm). Candidate catalyst materials were selected largely from metal oxides of the form ABO sub x (where A = Pb, Cd, Mn, Ti, Zr, La, Sr, Na, and B = Pt, Pd, Ir, Ru, Ni (Co) which were investigated and/or developed for one function only, O2 reduction or O2 evolution. The electrical conductivity requirement for catalysts may be lower, especially if integrated with a higher conductivity support. All candidate materials of acceptable conductivity are subjected to corrosion testing. Materials that survive chemical testing are examined for electrochemical corrosion activity. For more stringent corrosion testing, and for further evaluation of electrocatalysts (which generally show significant O2 evolution at at 1.4 V), samples are held at 1.6 V or 0.6 V for about 100 hours. The surviving materials are then physically and chemically analyzed for signs of degradation. To evaluate the bifunctional oxygen activity of candidate catalysts, Teflon-bonded electrodes are fabricated and tested in a floating electrode configuration. Many of the experimental materials being studied have required development of a customized electrode fabrication procedure. In advanced development, the goal is to reduce the polarization to about 300 to 350 mV. Approximately six support materials and five catalyst materials were identified to date for further development. The test results will be described.

  13. Estimated Infiltration, Percolation, and Recharge Rates at the Rillito Creek Focused Recharge Investigation Site, Pima County, Arizona

    USGS Publications Warehouse

    Hoffmann, John P.; Blasch, Kyle W.; Pool, Don R.; Bailey, Matthew A.; Callegary, James B.

    2007-01-01

    A large fraction of ground water stored in the alluvial aquifers in the Southwest is recharged by water that percolates through ephemeral stream-channel deposits. The amount of water currently recharging many of these aquifers is insufficient to meet current and future demands. Improving the understanding of streambed infiltration and the subsequent redistribution of water within the unsaturated zone is fundamental to quantifying and forming an accurate description of streambed recharge. In addition, improved estimates of recharge from ephemeral-stream channels will reduce uncertainties in water-budget components used in current ground-water models. This chapter presents a summary of findings related to a focused recharge investigation along Rillito Creek in Tucson, Arizona. A variety of approaches used to estimate infiltration, percolation, and recharge fluxes are presented that provide a wide range of temporal- and spatial-scale measurements of recharge beneath Rillito Creek. The approaches discussed include analyses of (1) cores and cuttings for hydraulic and textural properties, (2) environmental tracers from the water extracted from the cores and cuttings, (3) seepage measurements made during sustained streamflow, (4) heat as a tracer and numerical simulations of the movement of heat through the streambed sediments, (5) water-content variations, (6) water-level responses to streamflow in piezometers within the stream channel, and (7) gravity changes in response to recharge events. Hydraulic properties of the materials underlying Rillito Creek were used to estimate long-term potential recharge rates. Seepage measurements and analyses of temperature and water content were used to estimate infiltration rates, and environmental tracers were used to estimate percolation rates through the thick unsaturated zone. The presence or lack of tritium in the water was used to determine whether or not water in the unsaturated zone infiltrated within the past 40 years

  14. Relation between grain size and modal composition in deep-sea gravity-flow deposits. Example from the Voirons Flysch (Gurnigel nappe, Chablais Prealps, France)

    NASA Astrophysics Data System (ADS)

    Ragusa, Jérémy; Kindler, Pascal

    2016-04-01

    A coupled analysis of modal composition, grain size and sedimentary features of gravity-flow deposits in the Gurnigel nappe shows that the transition from coarse proximal to fine distal deposits is accompanied by a change in composition from siliciclastic to calcareous. Such compositional variation should be taken into account when interpretating deep-sea deposits if sampling is restricted to a single part of the fan. The Chablais Prealps (Haute-Savoie, France) represent a well-preserved accretionary wedge in the Western Alps. They comprise a stack of northward-thrusted sedimentary cover nappes originating from the Ultrahelvetic realm (distal part of the European margin) to the southern part of the Piemont Ocean. The present study focuses on the Voirons Flysch, belonging to the Gurnigel nappe, which includes four formations consisting of gravity-flow deposits (from bottom to top): (1) the Voirons Sandstone Fm., composed of channel to lobe deposits; (2) the Vouan Conglomerate Fm., represented by the proximal part of a channel system; (3) the Boëge Marls Fm., constituted by distal lobe deposits; finally, (4) the Bruant Sandstone Fm., which consists in channel to lobe deposits. Recent biostratigraphic results using planktonic foraminifers attributed a Middle to Late Eocene age to the Voirons Flysch, which was formerly believed to range from the Paleocene to the Middle Eocene (based on calcareous nannofossils). A total of 270 thin sections with stained feldspars were prepared, representing the four formations of the Voirons Flysch. Circa 300 extrabasinal grains were counted per thin section using the classic Indiana method. In addition, the quantity of intrabasinal grains (i.e. bioclasts, glauconite), cement and porosity was analysed. Cement was stained with alizarine and potassium ferrocyanide. 200 grain-size measurements on ca. 100 samples were performed using 3D conversion and statistical moment analysis. Sedimentary observations for each sampled bed were

  15. Elastic properties and seismic anisotropy of the Seve Nappe Complex - Laboratory core measurements from the International Continental Drilling Project COSC-1 well, Åre, Sweden

    NASA Astrophysics Data System (ADS)

    Wenning, Q. C.; Almqvist, B. S. G.; Zappone, A. S.

    2015-12-01

    The COSC-1 scientific borehole was drilled in the summer of 2014 to ~2.5 km depth to study the structure and composition of the Middle Allochthon of the Central Scandinavian Caledonides. It crosscuts the amphibolite-grade lower part of the Seve nappe and intersects a mylonite zone in the lower 800 m of the borehole. We selected six core samples representing the primary lithologies in the COSC-1 borehole for laboratory investigation of elastic properties. The cores consisted of two amphibolites with differing grain sizes, a calc-silicate gneiss, a felsic gneiss, a coarse grained amphibole bearing gneiss, and a garnet bearing mylonitic schist from the basal shear zone. Both P- and S-waves were measured at ultrasonic frequency (1 MHz), and room temperature hydrostatic pressure conditions up to 260 MPa. Measurements were made along three mutually perpendicular directions, one perpendicular to foliation and two parallel to the foliation with one aligned with mineral lineation. Vp and Vs, anisotropy, and elastic properties are reported as an extrapolation of the high-pressure portion of the ultrasonic measurements back to the intersection with the zero pressure axis. The Vp and Vs in the direction perpendicular to foliation ranges from 5.51-6.67 km/s and 3.18-4.13 km/s, respectively. In the direction parallel to foliation the Vp and Vs ranges from 6.31-7.25 km/s and 3.52-4.35 km/s, respectively. Vp anisotropy ranges from 3% in the calc-silicate gneiss to 18% in mylonitic schist. Acoustic impedance estimations at lithostatic pressure conditions at base of the borehole (70 MPa) show that acoustic impedance contrast generating reflection coefficients between the basal shear zone and overlying units are significant enough to cause seismic reflections. Above the mylonite zone/shear zone, the reflectivity within the lower Seve nappe is due to the impedance contrast between the felsic gneiss and the amphibolite. This result fits with 3D seismic reflection imaging in the area of

  16. What controls the reactivation or preservation of distal ocean-continent transitions: the example of the Err-Platta nappes, SE Switzerland

    NASA Astrophysics Data System (ADS)

    Epin, Marie-Eva; Manatschal, Gianreto; Amann, Méderic

    2016-04-01

    Studies in the Alps suggest that remnants of former Ocean-Continent Transitions (OCT) can be preserved, even in internal parts of mountain belts. In the past, these units have been erroneously interpreted as either mélanges related to subduction channels or polyphase penetrative Alpine deformation. Good examples have been described from the eclogitic Piemonte units in the Western Alps and in Corsica [Beltrando et al., 2014], leading to the question of what may have controlled the preservation of these structures. In our study we used the example of the Err-Platta nappes that expose remnants of the OCT of the former Alpine Tethys. The aim of our presentation is to: 1) define the characteristic features of an OCT across a fossil magma-poor rifted margin, and 2) show the control of the rift-inherited structures during the subsequent reactivation of the OCT. The characteristics of OCTs at magma-poor rifted margins are the juxtaposition of serpentinized mantle and crustal rocks and pre-rift sediments limited by brittle extensional detachment faults sealed by syn- and post-tectonic sediments locally associated with magmatic rocks. Thus, in contrast to proximal margins, where lithologies are continuous layer cakes, OCTs are characterized by non-continuous layers and isolated blocks. To identify extensional detachment faults in mountain belts, different fingerprints can be found such as fault rocks (gouges and cataclasites) that bear a mantle derived fluid signature, or the occurrence of massive breccias that contain clasts of the underlying exhumed basement. Using field examples, we will show how Alpine structures selectively reactivated some inherited structures of the OCT, while others remained undeformed and were preserved in the nappe stack. How far the complex morphology, fault architecture and rheology of OCTs control the reactivation is still unclear, however, it appears that serpentinization fronts, or former extensional detachment faults may have played a key

  17. Remnants of a hyperextended passive margin in a Caledonian mélange unit below the Jotun nappe, B\\overdalen, Central-south Norway

    NASA Astrophysics Data System (ADS)

    Alsaif, Manar; Jakob, Johannes; Andersen, Torgeir; Corfu, Fernando

    2015-04-01

    The Scandinavian Caledonides have been long studied, yet their ever unfolding complexity renders them far from being fully understood. It has been recognized that the Caledonian Allochthons have neither a linear nor straightforward along-strike relationship (Corfu et al. 2014). A mélange unit has been recently identified as a separate tectonic unit (Andersen et al. 2012). This unit is structurally positioned below crystalline nappes previously assigned to the Middle Allochthon. The mélange comprises meta-sediments and minor meta-basalt/gabbro, but most intriguingly, numerous solitary meta-peridotites. These occur as 'Alpine type' meta-peridotites, serpentinites, soapstones and detrital serpentinites. We present results of a field study of the mélange in the B\\overdalen area, structurally below the Jotun nappe, and suggest that this provides further evidence that the regional mélange unit was formed in a hyperextended passive margin. The meta-peridotites represent exhumed serpentinized mantle and are intimately associated with meta-sediments. The sediments are garnetiferous chlorite-muscovite schists, graphitic schists, phyllites, amphibolites, meta-sandstones as well as quartzite-pebble dominated conglomerates. It is suggested that this highly heterogeneous unit formed during the early stages of rifting and hyperextension along the Baltican passive margin. Characteristics of the detrital peridotites suggests that serpentinite-talc protrusions may have formed islands. The processes involved are observed on modern margins where the best-studied example is the Iberia-Newfoundland passive margin. Work in present-day margins (mostly seismic reflection data) elucidate the large-scale structure of hyperextended margins, while studies of ancient exposed examples in mountain belts provide insight into the lithology, geochemistry and details of these margins. The widespread distribution of hyperextended margins in modern margins and the increasing number of recognizable

  18. Using environmental isotopes in the study of the recharge-discharge mechanisms of the Yarmouk catchment area in Jordan

    NASA Astrophysics Data System (ADS)

    Salameh, Elias

    groundwater, which, from the highlands towards the Jordan Valley, shows increasing enrichment in isotopes. The highlands aquifer, with its groundwater depleted in isotopes, becomes confined towards the Jordan Valley; and, due to its confining pressure, leaks water upwards into the overlying aquifers causing their water to become less enriched in isotopes. Water depleted in its isotopic composition also seeps upward to the ground surface at the mountain foothills through faults and fissures. Les zones de recharge, les mécanismes d'écoulement et les zones de décharges des différentes masses d'eau souterraine sous le bassin versant de la rivière Yarmouk en Jordanie, étaient expliquées de manière ambiguë par les seuls outils isotopiques. Le long de la parti Jordanienne du bassin versant de la rivière Yarmouk l'eau souterraine provient de différents aquifères et se distinguent par leur type et leur composition chimique, selon que l'eau provient du même ou des différents aquifères. Les mécanismes conventionnels de recharge et de décharge, bilan hydrologique ne donnaient pas d'explications satisfaisantes concernant les variations chimiques et les différents types d'eau. En appliquant les isotopes environnementaux combinés aux effets de l'altitude sur les variations des teneurs isotopiques (l'altitude varie de 250 à 1,300 m sur une distance de 20 km.) et en prenant en considération les effets de ré-évaporation sur l'appauvrissement et l'enrichissement isotopique des eaux pluviales ont fortement contribués à une meilleure compréhension des mécanismes de recharge des différents aquifères. Les précipitations annuelles sont comprises entre 600 mm dans les zones en altitude et 350 mm dans la vallée de la Jordanie. Les écoulements de l'eau souterraine sont dirigés des zones en altitude vers la vallée de la Jordanie. Les eaux souterraines des zones en altitude sont isotopiquement appauvries (δO18 = -6, δD = -30), les eaux souterraines des zones de moyenne

  19. On the interpretation of recharge estimates from steady-state model calibrations.

    PubMed

    Anderson, William P; Evans, David G

    2007-01-01

    Ground water recharge is often estimated through the calibration of ground water flow models. We examine the nature of calibration errors by considering some simple mathematical and numerical calculations. From these calculations, we conclude that calibrating a steady-state ground water flow model to water level extremes yields estimates of recharge that have the same value as the time-varying recharge at the time the water levels are measured. These recharge values, however, are a subdued version of the actual transient recharge signal. In addition, calibrating a steady-state ground water flow model to data collected during periods of rising water levels will produce recharge values that underestimate the actual transient recharge. Similarly, calibrating during periods of falling water levels will overestimate the actual transient recharge. We also demonstrate that average water levels can be used to estimate the actual average recharge rate provided that water level data have been collected for a sufficient amount of time.

  20. Thermal Methods for Investigating Ground-Water Recharge

    USGS Publications Warehouse

    Blasch, Kyle W.; Constantz, Jim; Stonestrom, David A.

    2007-01-01

    Recharge of aquifers within arid and semiarid environments is defined as the downward flux of water across the regional water table. The introduction of recharging water at the land surface can occur at discreet locations, such as in stream channels, or be distributed over the landscape, such as across broad interarroyo areas within an alluvial ground-water basin. The occurrence of recharge at discreet locations is referred to as focused recharge, whereas the occurrence of recharge over broad regions is referred to as diffuse recharge. The primary interest of this appendix is focused recharge, but regardless of the type of recharge, estimation of downward fluxes is essential to its quantification. Like chemical tracers, heat can come from natural sources or be intentionally introduced to infer transport properties and aquifer recharge. The admission and redistribution of heat from natural processes such as insolation, infiltration, and geothermal activity can be used to quantify subsurface flow regimes. Heat is well suited as a ground-water tracer because it provides a naturally present dynamic signal and is relatively harmless over a useful range of induced perturbations. Thermal methods have proven valuable for recharge investigations for several reasons. First, theoretical descriptions of coupled water-and-heat transport are available for the hydrologic processes most often encountered in practice. These include land-surface mechanisms such as radiant heating from the sun, radiant cooling into space, and evapotranspiration, in addition to the advective and conductive mechanisms that usually dominate at depth. Second, temperature is theoretically well defined and readily measured. Third, thermal methods for depths ranging from the land surface to depths of hundreds of meters are based on similar physical principles. Fourth, numerical codes for simulating heat and water transport have become increasingly reliable and widely available. Direct measurement of water

  1. Fate of human viruses in groundwater recharge systems

    SciTech Connect

    Vaughn, J.M.; Landry, E.F.

    1980-03-01

    The overall objective of this research program was to determine the ability of a well-managed tertiary effluent-recharge system to return virologically acceptable water to the groundwater aquifer. The study assessed the quality of waters renovated by indigenous recharge operations and investigated a number of virus-soil interrelationships. The elucidation of the interactions led to the establishment of basin operating criteria for optimizing virus removal. Raw influents, chlorinated tertiary effluents, and renovated wastewater from the aquifer directly beneath a uniquely designed recharge test basin were assayed on a weekly basis for the presence of human enteroviruses and coliform bacteria. High concentrations of viruses were routinely isolated from influents but were isolated only on four occasions from tertiary-treated sewage effluents. In spite of the high quality effluent being recharged, viruses were isolated from the groundwater observation well, indicating their ability to penetrate the unsaturated zone. Results of poliovirus seeding experiments carried out in the test basin clearly indicated the need to operate recharge basins at low (e.g. 1 cm/h) infiltration rates in areas having soil types similar to those found at the study site. The method selected for reducing the test basin infiltration rate involved clogging the basin surface with settled organic material from highly turbid effluent. Alternative methods for slowing infiltration rates are discussed in the text.

  2. Factors affecting areas contributing recharge to wells in shallow aquifers

    USGS Publications Warehouse

    Reilly, Thomas E.; Pollock, David W.

    1993-01-01

    The source of water to wells is ultimately the location where the water flowing to a well enters the boundary surface of the ground-water system. In ground-water systems that receive most of their water from areal recharge, the location of the water entering the ground-water system is at the water table. The area contributing recharge to a discharging well is the surface area that defines the location of the water entering the ground-water system at the water table that flows to the well and is eventually discharged from the well. The calculation of areas contributing recharge to wells is complex because flow paths in ground-water systems change in response to development, and the aquifer material in ground-water systems is heterogeneous and is hidden from direct observation . Hypothetical experiments were undertaken to show the complexities in the delineation of areas contributing recharge to wells. Four different 'cases' are examined to demonstrate the effect of different conceptualized aquifer frameworks on deterministically calculated areas contributing recharge. The main conclusion drawn from the experiments is that, in order to understand the cause and effect relations that affect the quality of water derived from wells, the importance and nature of the variability in the ground-waterflow system must be considered and accounted for in any efforts to 'protect' the water supply.

  3. Groundwater recharge from Long Lake, Indiana Dunes National Lakeshore

    SciTech Connect

    Isiorho, S.A.; Beeching, F.M. . Geosciences Dept.); Whitman, R.L.; Stewart, P.M. . Indiana Dunes National Lakeshore); Gentleman, M.A.

    1992-01-01

    Long Lake, located between Lake Michigan and the Dune-complexes of Indiana Dunes, was formed during Pleistocene and Holocene epochs. The lake is currently being studied to understand the detailed hydrology. One of the objective of the study is to understand the hydrologic relationship between the lake and a water treatment holding pond to the northeast. Understanding the water movement between the two bodies of water, if any, would be very important in the management and protection of nature preserves in the area. Seepage measurement and minipiezometric tests indicate groundwater recharge from Long Lake. The groundwater recharge rate is approximately 1.40 to 22.28 x 10[sup [minus]4] m/day. An estimate of the amount of recharge of 7.0 x 10[sup 6] m[sup 3]/y may be significant in terms of groundwater recharge of the upper aquifer system of the Dunes area. The water chemistry of the two bodies of water appears to be similar, however, the pH of the holding pond is slightly alkaline (8.5) while that of Long Lake is less alkaline (7.7). There appears to be no direct contact between the two bodies of water (separated by approximately six meters of clay rich sediment). The geology of the area indicates a surficial aquifer underlying Long Lake. The lake should be regarded as a recharge area and should be protected from pollutants as the degradation of the lake would contaminate the underlying aquifer.

  4. Recharge from a subsidence crater at the Nevada test site

    USGS Publications Warehouse

    Wilson, G. V.; Ely, D.M.; Hokett, S. L.; Gillespie, D. R.

    2000-01-01

    Current recharge through the alluvial fans of the Nevada Test Site (NTS) is considered to be negligible, but the impact of more than 400 nuclear subsidence craters on recharge is uncertain. Many of the craters contain a playa region, but the impact of these playas has not been addressed. It was hypothesized that a crater playa would focus infiltration through the surrounding coarser-grained material, thereby increasing recharge. Crater U5a was selected because it represented a worst case for runoff into craters. A borehole was instrumented for neutron logging beneath the playa center and immediately outside the crater. Physical and hydraulic properties were measured along a transect in the crater and outside the crater. Particle-size analysis of the 14.6 m of sediment in the crater and morphological features of the crater suggest that a large ponding event of ≈63000 m3 had occurred since crater formation. Water flow simulations with HYDRUS-2D, which were corroborated by the measured water contents, suggest that the wetting front advanced initially by as much as 30 m yr−1 with a recharge rate 32 yr after the event of 2.5 m yr−1Simulations based on the measured properties of the sediments suggest that infiltration will occur preferentially around the playa perimeter. However, these sediments were shown to effectively restrict future recharge by storing water until removal by evapotranspiration (ET). This work demonstrated that subsidence craters may be self-healing.

  5. Coupling stormwater capture and managed aquifer recharge

    NASA Astrophysics Data System (ADS)

    Beganskas, S.; Fisher, A. T.; Los Huertos, M.; Hill, C. L.

    2014-12-01

    We are evaluating the use of stormwater runoff as a source for managed aquifer recharge (MAR), using data from an operational field site to address two questions: (1) How much stormwater can be captured and infiltrated with this system? (2) What is the impact of sediment delivered to the infiltration basin with the stormwater, and what maintenance would be required to sustain favorable infiltration conditions? Our field site is a working ranch in the Pajaro Valley, central coastal California, where runoff from ~48 ha (120 ac) is directed into a 1-ha (2.5 ac) infiltration basin. We instrumented the site for water years (WY) 2012, 2013, and 2014 to measure local precipitation, total inflow, and sediment accumulation. In WY14, we added a network of instruments that reports some of these data in real time. WY12, WY13, and WY14 were dry, with total precipitation 50%, 70%, and 45% of the regional long-term average, respectively. In WY12, precipitation was spread over many storms, and total inflow was 5,600 m3 (4.5 ac-ft). A series of more intense storms in WY13 delivered 39,000 m3 (31 ac-ft) of total inflow. The driest year of our study so far, WY14, included the most intense rainfall we have recorded, and total inflow was 42,000 m3 (34 ac-ft). These results demonstrate that both precipitation amount and intensity influence how much stormwater runoff is generated. During a wetter year, we expect this system could collect at least 134,000 m2 (100 ac-ft) of runoff. Sediment accumulation in the infiltration basin in WY13 ranged from 0-8 cm, but in WY14 was no greater than 1 cm. As total inflow for these years was similar, sediment load of runoff captured during WY14 was much smaller than that of WY13. Grain size analyses demonstrate that fine material is preferentially delivered to the infiltration basin, while coarser material is removed during transport. These data will be linked to a regional model and used to develop additional stormwater-MAR projects in this area.

  6. A new model for the formation of a spaced crenulation (shear band) cleavage in the Dalradian rocks of the Tay Nappe, SW Highlands, Scotland

    NASA Astrophysics Data System (ADS)

    Geoff Tanner, P. W.

    2016-03-01

    The main conclusion of this study is that non-coaxial strain acting parallel to a flat-lying D1 spaced cleavage was responsible for the formation of the D2 spaced crenulation (shear band) cleavage in Dalradian rocks of Neoproterozoic-Lower Ordovician age in the SW Highlands, Scotland. The cm-dm-scale D2 microlithons are asymmetric; have a geometrically distinctive nose and tail; and show a thickened central portion resulting from back-rotation of the constituent D1 microlithons. The current terminology used to describe crenulation cleavages is reviewed and updated. Aided by exceptional 3D exposures, it is shown how embryonic D2 flexural-slip folds developed into a spaced cleavage comprising fold-pair domains wrapped by anastomosing cleavage seams. The bulk strain was partitioned into low-strain domains separated by zones of high non-coaxial strain. This new model provides a template for determining the sense of shear in both low-strain situations and in ductile, higher strain zones where other indicators, such as shear folds, give ambiguous results. Analogous structures include tectonic lozenges in shear zones, and flexural-slip duplexes. Disputes over the sense and direction of shear during emplacement of the Tay Nappe, and the apparently intractable conflict between minor fold asymmetry and shear sense, appear to be resolved.

  7. Stratigraphic and geochemical study of the organic-rich black shales in the Tarcău Nappe of the Moldavidian Domain (Carpathian Chain, Romania)

    NASA Astrophysics Data System (ADS)

    Belayouni, Habib; di Staso, Angelida; Guerrera, Francesco; Martín Martín, Manuel; Miclǎuş, Crina; Serrano, Francisco; Tramontana, Mario

    2009-02-01

    An integrated stratigraphic analysis has been made of the Tarcău Nappe (Moldavidian Domain, Eastern Romanian Carpathians), coupled with a geochemical study of organic-rich beds. Two Main Sequence Boundaries (Early Oligocene and near to the Oligocene-Aquitanian boundary, respectively) divide the sedimentary record into three depositional sequences. The sedimentation occurred in the central area of a basin supplied by different and opposite sources. The high amount of siliciclastics at the beginning of the Miocene marks the activation of the “foredeep stage”. The successions studied are younger than previously thought and they more accurately date the deformation of the different Miocene phases affecting the Moldavidian Basin. The intervals with black shales identified are related to two main separate anoxic episodes with an age not older than Late Rupelian and not before Late Chattian. The most important organic-rich beds correspond to the Lower Menilites, Bituminous Marls and Lower Dysodilic Shales Members (Interval 2). These constitute a good potential source rock for petroleum, with homogeneous Type II oil-prone organic matter, highly lipidic and thermally immature. The deposition of black shales has been interpreted as occurring within a deep, periodically isolated and tectonically controlled basin.

  8. Artificial-recharge experiments and operations on the Southern High Plains of Texas and New Mexico

    USGS Publications Warehouse

    Brown, Richmond F.; Signor, Donald C.

    1973-01-01

    Experiments using highly turbid water from playa lakes for injection into the Ogallala Formation have resulted in greatly decreased yield of the recharge wells, Recharge of ground or surface water of good quality has indicated, however, that injection through wells is an effective method of recharging the aquifer. Water that is slightly turbid can be successfully injected for a period of time, but generally results in constantly declining yields and capacity for recharge. Redevelopment through pumping and surging significantly prolongs the life of recharge wells under some conditions. Surface spreading is little practiced on the High Plains, but locally may be a feasible means of artificial recharge.

  9. Des Vents et des Jets Astrophysiques

    NASA Astrophysics Data System (ADS)

    Sauty, C.

    well expected result from the theory. Although, collimation may be conical, paraboloidal or cylindrical (Part 4), cylindrical collimation is the more likely to occur. The shape of outflows may then be used as a tool to predict physical conditions on the flows or on their source. L'éjection continue de plasma autour d'objets massifs est un phénomène largement répandu en astrophysique, que ce soit sous la forme du vent solaire, de vents stellaires, de jets d'étoiles en formation, de jets stellaires autour d'objets compacts ou de jets extra-galactiques. Cette zoologie diversifiée fait pourtant l'objet d'un commun effort de modélisation. Le but de cette revue est d'abord de présenter qualitativement le développement, depuis leur origine, des diverses théories de vents (Partie 1) et l'inter disciplinarité dans ce domaine. Il s'agit d'une énumération, plus ou moins exhaustive, des idées proposées pour expliquer l'accélération et la morphologie des vents et des jets, accompagnée d'une présentation sommaire des aspects observationnels. Cette partie s'abstient de tout aspect faisant appel au formalisme mathématique. Ces écoulements peuvent être décrits, au moins partiellement, en résolvant les équations magnétohydrodynamiques, axisymétriques et stationnaires. Ce formalisme, à la base de la plupart des théories, est exposé dans la Partie 2. Il permet d'introduire quantitativement les intégrales premières qu'un tel système possède. Ces dernières sont amenées à jouer un rôle important dans la compréhension des phénomènes d'accélération ou de collimation, en particulier le taux de perte de masse, le taux de perte de moment angulaire ou l'énergie du rotateur magnétique. La difficulté de modélisation réside dans l'existence de points critiques, propres aux équations non linéaires, qu'il faut franchir. La nature physique et la localisation de ces points critiques fait l'objet d'un débat important car ils sont la clef de voute de la r

  10. Crab Burrows are Important Conduits for Groundwater Recharge in Bangladesh

    NASA Astrophysics Data System (ADS)

    Stahl, M.; Tarek, M. H.; Yeo, D. C.; Badruzzaman, A.; Harvey, C. F.

    2013-12-01

    Recent research suggests that recharge from man-made ponds may stimulate arsenic mobilization within Bangladeshi aquifers. Man-made ponds are widespread throughout Bangladesh and are generally underlain by low permeability clays that could potentially limit flow to the sandy aquifer below if they are not compromised by preferential flow paths. Animal borrows are one common type of preferential flow path through surface clays. Across the Ganges Delta, terrestrial crabs dig borrows, sometimes as long as 10 meters. In our study pond in Munshiganj, Bangladesh we found crab burrows extending through the surficial clays and down into the shallow aquifer spaced approximately every meter. We use these field observations along with a novel, coupled isotope and water balance model to quantify the fluxes into and out of the pond. We show that nearly all of the aquifer recharge from the pond is through crab burrows which have enhanced the hydraulic conductivity of the surficial sediments by several orders of magnitude. In addition we show that the recharging pond water is shifting the solute composition of water beneath the pond. We suggest that, as a result of crab burrows, young ponds may contribute large fluxes of recharge water whereas older ponds may contribute little recharge to the aquifer. All terrestrial crabs have gills that must remain moist to allow for respiration. So, to ensure an uninterrupted water source, their borrows must reach the maximum depth that the water table drops to seasonally after irrigation ceases and before the onset of the monsoon. Once a pond is installed crabs living within the sediments that now make up the new pond bottom would no longer need to construct burrows to ensure a constant supply of water. Over time, burrows that existed prior to pond construction can clog. Water balance data for an old pond at our study site indicates that this pond contributes less recharge than our newly constructed pond.

  11. Estimating ground water recharge from topography, hydrogeology, and land cover.

    PubMed

    Cherkauer, Douglas S; Ansari, Sajjad A

    2005-01-01

    Proper management of ground water resources requires knowledge of the rates and spatial distribution of recharge to aquifers. This information is needed at scales ranging from that of individual communities to regional. This paper presents a methodology to calculate recharge from readily available ground surface information without long-term monitoring. The method is viewed as providing a reasonable, but conservative, first approximation of recharge, which can then be fine-tuned with other methods as time permits. Stream baseflow was measured as a surrogate for recharge in small watersheds in southeastern Wisconsin. It is equated to recharge (R) and then normalized to observed annual precipitation (P). Regression analysis was constrained by requiring that the independent and dependent variables be dimensionally consistent. It shows that R/P is controlled by three dimensionless ratios: (1) infiltrating to overland water flux, (2) vertical to lateral distance water must travel, and (3) percentage of land cover in the natural state. The individual watershed properties that comprise these ratios are now commonly available in GIS data bases. The empirical relationship for predicting R/P developed for the study watersheds is shown to be statistically viable and is then tested outside the study area and against other methods of calculating recharge. The method produces values that agree with baseflow separation from streamflow hydrographs (to within 15% to 20%), ground water budget analysis (4%), well hydrograph analysis (12%), and a distributed-parameter watershed model calibrated to total streamflow (18%). It has also reproduced the temporal variation over 5 yr observed at a well site with an average error < 12%.

  12. Injectabilite des coulis de ciment dans des milieux fissures

    NASA Astrophysics Data System (ADS)

    Mnif, Thameur

    Le travail presente ici est un bilan du travaux de recherche effectues sur l'injectabilite des coulis de ciment dans lu milieux fissures. Un certain nombre de coulis a base de ciment Portland et microfin ont ete selectionnes afin de caracteriser leur capacite a penetrer des milieux fissures. Une partie des essais a ete menee en laboratoire. L'etude rheologique des differents melanges a permis de tester l'influence de l'ajout de superplastifiant et/ou de fumee de silice sur la distribution granulometrique des coulis et par consequent sur leur capacite a injecter des colonnes de sable simulant un milieu fissure donne. La classe granulometrique d'un coulis, sa stabilite et sa fluidite sont apparus comme les trois facteurs principaux pour la reussite d'une injection. Un facteur de finesse a ete defini au cours de cette etude: base sur la classe granulometrique du ciment et sa stabilite, il peut entrer dans la formulation theorique du debit d'injection avant application sur chantier. La deuxieme et derniere partie de l'etude presente les resultats de deux projets de recherche sur l'injection realises sur chantier. L'injection de dalles de beton fissurees a permis le suivi de l'evolution des pressions avec la distance au point d'injection. L'injection de murs de maconnerie a caractere historique a montre l'importance de la definition de criteres de performance des coulis a utiliser pour traiter un milieu donne et pour un objectif donne. Plusieurs melanges peuvent ainsi etre predefinis et mis a disposition sur le chantier. La complementarite des ciments traditionnels et des ciments microfins devient alors un atout important. Le choix d'utilisation de ces melanges est fonction du terrain rencontre. En conclusion, cette recherche etablit une methodologie pour la selection des coulis a base de ciment et des pressions d'injection en fonction de l'ouverture des fissures ou joints de construction.

  13. Focused Ground-Water Recharge in the Amargosa Desert Basin

    USGS Publications Warehouse

    Stonestrom, David A.; Prudic, David E.; Walvoord, Michelle A.; Abraham, Jared D.; Stewart-Deaker, Amy E.; Glancy, Patrick A.; Constantz, Jim; Laczniak, Randell J.; Andraski, Brian J.

    2007-01-01

    The Amargosa River is an approximately 300-kilometer long regional drainage connecting the northern highlands on the Nevada Test Site in Nye County, Nev., to the floor of Death Valley in Inyo County, Calif. Streamflow analysis indicates that the Amargosa Desert portion of the river is dry more than 98 percent of the time. Infiltration losses during ephemeral flows of the Amargosa River and Fortymile Wash provide the main sources of ground-water recharge on the desert-basin floor. The primary use of ground water is for irrigated agriculture. The current study examined ground-water recharge from ephemeral flows in the Amargosa River by using streamflow data and environmental tracers. The USGS streamflow-gaging station at Beatty, Nev., provided high-frequency data on base flow and storm runoff entering the basin during water years 1998?2001. Discharge into the basin during the four-year period totaled 3.03 million cubic meters, three quarters of which was base flow. Streambed temperature anomalies indicated the distribution of ephemeral flows and infiltration losses within the basin. Major storms that produced regional flow during the four-year period occurred in February 1998, during a strong El Ni?o that more than doubled annual precipitation, and in July 1999. The study also quantified recharge beneath undisturbed native vegetation and irrigation return flow beneath irrigated fields. Vertical profiles of water potential and environmental tracers in the unsaturated zone provided estimates of recharge beneath the river channel (0.04?0.09 meter per year) and irrigated fields (0.1?0.5 meter per year). Chloride mass-balance estimates indicate that 12?15 percent of channel infiltration becomes ground-water recharge, together with 9?22 percent of infiltrated irrigation. Profiles of potential and chloride beneath the dominant desert-shrub vegetation suggest that ground-water recharge has been negligible throughout most of the basin since at least the early Holocene

  14. Recharge areas and hydrochemistry of carbonate springs issuing from Semmering Massif, Austria, based on long-term oxygen-18 and hydrochemical data evidence

    NASA Astrophysics Data System (ADS)

    Yehdegho, Beyene; Reichl, Peter

    2002-10-01

    Résumé. Les teneurs en oxygène-18 et l'hydrochimie des sources émergeant du massif de Semmering ont été suivies de manière intensive dans le but de caractériser les zones de recharge et l'évolution hydrochimique. L'effet d'altitude sur le δ18O a été déterminé grâce aux données isotopiques et hydrogéologiques de petites sources de référence, principalement en terrains cristallins; cet effet est d'environ -0,27 et -0,21‰ par 100 m pour les versants respectivement nord et sud du massif. En appliquant ces valeurs, l'altitude moyenne de recharge des sources a été calculée. Pour les sources à fort débit issues des carbonates, elle est comprise entre 1,100 et 1,400 m, compatible avec le cadre topographique et hydrogéologique des calcaires et des dolomies de l'Austro-alpin inférieur alimentant ces sources. La composition chimique des sources des carbonates est dominée par les ions Ca2+, Mg2+, HCO3- et SO42-. Les sources sont presque toutes proches de la saturation par rapport à la calcite, mais sont sous-saturées en dolomite (sauf quelques sources proches de la saturation). Comme cela est habituel en ce qui concerne le dioxyde de carbone fourni par les sols en régions montagneuses, la pCO2 équilibrante moyenne est faible, comprise entre 10-3.0 et 10-2.5 atm (0,1 à 0,3% en volume). En ce qui concerne les variations à long terme, le pH, SIc, Sid et la pCO2 équilibrante sont soumis à des variations saisonnières, alors que les concentrations en Ca2+, Mg2+ et HCO3- ne varient pratiquement pas. En intégrant les résultats de δ18O et les données hydrochimiques, la variabilité altitudinale du chimisme des eaux souterraines des carbonates est démontrée. Reflétant les variations d'activité biologique et des conditions de recharge dans les zones d'alimentation, une covariation négative résulte de l'altitude de recharge et de la pCO2 et la concentration en HCO3- n'est pas modifiée par aucun des termes source ou puits, ce qui fait varier

  15. Recharge areas and hydrochemistry of carbonate springs issuing from Semmering Massif, Austria, based on long-term oxygen-18 and hydrochemical data evidence

    NASA Astrophysics Data System (ADS)

    Yehdegho, Beyene; Reichl, Peter

    2002-10-01

    Résumé. Les teneurs en oxygène-18 et l'hydrochimie des sources émergeant du massif de Semmering ont été suivies de manière intensive dans le but de caractériser les zones de recharge et l'évolution hydrochimique. L'effet d'altitude sur le δ18O a été déterminé grâce aux données isotopiques et hydrogéologiques de petites sources de référence, principalement en terrains cristallins; cet effet est d'environ -0,27 et -0,21‰ par 100 m pour les versants respectivement nord et sud du massif. En appliquant ces valeurs, l'altitude moyenne de recharge des sources a été calculée. Pour les sources à fort débit issues des carbonates, elle est comprise entre 1,100 et 1,400 m, compatible avec le cadre topographique et hydrogéologique des calcaires et des dolomies de l'Austro-alpin inférieur alimentant ces sources. La composition chimique des sources des carbonates est dominée par les ions Ca2+, Mg2+, HCO3- et SO42-. Les sources sont presque toutes proches de la saturation par rapport à la calcite, mais sont sous-saturées en dolomite (sauf quelques sources proches de la saturation). Comme cela est habituel en ce qui concerne le dioxyde de carbone fourni par les sols en régions montagneuses, la pCO2 équilibrante moyenne est faible, comprise entre 10-3.0 et 10-2.5 atm (0,1 à 0,3% en volume). En ce qui concerne les variations à long terme, le pH, SIc, Sid et la pCO2 équilibrante sont soumis à des variations saisonnières, alors que les concentrations en Ca2+, Mg2+ et HCO3- ne varient pratiquement pas. En intégrant les résultats de δ18O et les données hydrochimiques, la variabilité altitudinale du chimisme des eaux souterraines des carbonates est démontrée. Reflétant les variations d'activité biologique et des conditions de recharge dans les zones d'alimentation, une covariation négative résulte de l'altitude de recharge et de la pCO2 et la concentration en HCO3- n'est pas modifiée par aucun des termes source ou puits, ce qui fait varier

  16. Electrolyte for use in high energy lithium based rechargeable electrochemical cell and rechargeable electrochemical cell including the electrolyte

    NASA Astrophysics Data System (ADS)

    Mammone, R. J.; Binder, M.

    1986-04-01

    The general object of this invention is to provide a lithium based rechargeable electrochemical cell having an improved capacity. A more specific object of the invention is to provide an electrolyte for such a cell. A still further object of the invention is to provide such a cell. A still further object of the invention is to provide such a rechargeable electrochemical cell that permits the oxidation of dithionite to occur without using chlorine as an intermediate oxidizing agent. It has now been found that the aforementioned objects can be attained by providing an electrolyte including bromine dissolved in the liquid complex Li(s02)3A1C14.

  17. Potential for Recharge in Agricultural Soils of the Mississippi Delta

    NASA Astrophysics Data System (ADS)

    Perkins, K. S.; Nimmo, J. R.; Coupe, R. H.; Rose, C. E.; Manning, M. A.

    2007-12-01

    Ground water models predict that 5 percent or less of precipitation in the Mississippi Delta region recharges the heavily-used alluvial aquifer; however the presence of agricultural chemicals in ground water suggests more substantial recharge. In a preliminary assessment of the potential for aerial recharge through the agricultural soils of the Bogue Phalia basin in the Mississippi Delta, we applied a method for rapidly measuring field- saturated hydraulic conductivity (Kfs) in 26 locations in cotton and soybean fields. The technique makes use of a portable falling-head, small-diameter, single-ring infiltrometer and an analytical formula for Kfs that compensates both for falling head and for subsurface radial spreading. Soil samples were also collected at the surface and at about 6 cm depth at each location for particle size analysis. Kfs values are generally higher than anticipated and vary over more than three orders of magnitude from 1x10-2 to 5x10-6 cm/s. There is also a correlation between Kfs and mean particle size which may prove useful in generalizing recharge rates over larger areas. A 2-m ring infiltration test is planned that will include the use of tracers and subsurface instruments for measuring water content and matric potential from the near surface to about 5 m to evaluate flow and transport below the root zone.

  18. Implantable wireless battery recharging system for bladder pressure chronic monitoring.

    PubMed

    Young, Darrin J; Cong, Peng; Suster, Michael A; Damaser, Margot

    2015-11-21

    This paper presents an implantable wireless battery recharging system design for bladder pressure chronic monitoring. The wireless recharging system consists of an external 15 cm-diameter 6-turn powering coil and a silicone-encapsulated implantable rectangular coil with a dimension of 7 mm × 17 mm × 2.5 mm and 18 turns, which further encloses a 3 mm-diameter and 12 mm-long rechargeable battery, two ferrite rods, an ASIC, and a tuning capacitor. For a constant recharging current of 100 μA, an RF power of 700 μW needs to be coupled into the implantable module through the tuned coils. Analyses and experiments confirm that with the two coils aligned coaxially or with a 6 cm axial offset and a tilting angle of 30°, an external power of 3.5 W or 10 W is required, respectively, at an optimal frequency of 3 MHz to cover a large implant depth of 20 cm.

  19. Electrolytes for rechargeable lithium batteries. Research and development technical report

    SciTech Connect

    Hunger, H.F.

    1981-09-01

    Theoretical considerations predict increased stability of cyclic ethers and diethers against reductive cleavage by lithium if the ethers have 2 methyl substitution. Diethers are solvents with low viscosity which are desirable for high rate rechargeable lithium batteries. Synergistic, mixed solvent effects increase electrolyte conductance and rate capability of lithium intercalating cathodes.

  20. Effects of recharge wells and flow barriers on seawater intrusion.

    PubMed

    Luyun, Roger; Momii, Kazuro; Nakagawa, Kei

    2011-01-01

    The installation of recharge wells and subsurface flow barriers are among several strategies proposed to control seawater intrusion on coastal groundwater systems. In this study, we performed laboratory-scale experiments and numerical simulations to determine the effects of the location and application of recharge wells, and of the location and penetration depth of flow barriers, on controlling seawater intrusion in unconfined coastal aquifers. We also compared the experimental results with existing analytical solutions. Our results showed that more effective saltwater repulsion is achieved when the recharge water is injected at the toe of the saltwater wedge. Point injection yields about the same repulsion compared with line injection from a screened well for the same recharge rate. Results for flow barriers showed that more effective saltwater repulsion is achieved with deeper barrier penetration and with barriers located closer to the coast. When the flow barrier is installed inland from the original toe position however, saltwater intrusion increases with deeper barrier penetration. Saltwater repulsion due to flow barrier installation was found to be linearly related to horizontal barrier location and a polynomial function of the barrier penetration depth.

  1. Oxygen electrodes for rechargeable alkaline fuel cells-II

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.

    1989-01-01

    The primary objective of this program is the investigation and development of electrocatalysts and supports for the positive electrode of moderate temperature single-unit rechargeable alkaline fuel cells. Approximately six support materials and five catalyst materials have been identified to date for further development.

  2. Oxygen electrodes for rechargeable alkaline fuel cells, 3

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.; Mccatty, S. A.

    1991-01-01

    The investigation and development of electrocatalysts and supports for the positive electrode of moderate temperature single unit rechargeable alkaline fuel cells is described. Focus is on chemical and electrochemical stability and O2 reduction/evolution activity of the electrode in question.

  3. Moderate temperature rechargeable NaNiS2 cells

    NASA Technical Reports Server (NTRS)

    Abraham, K. M.

    1983-01-01

    A rechargeable sodium battery of the configuration, liquid Na/beta double prime -Al2O3/molten NaAlCl4, NiS2, operating in the temperature range of 170 to 190 C, is described. This battery is capable of delivering or = to 50 W-hr/1b and 1000 deep discharge/charge cycles.

  4. Managed Aquifer Recharge in Italy: present and prospects.

    NASA Astrophysics Data System (ADS)

    Rossetto, Rudy

    2015-04-01

    On October the 3rd 2014, a one-day Workshop on Managed Aquifer Recharge (MAR) experiences in Italy took place at the GEOFLUID fair in Piacenza. It was organized within the framework of the EIP AG 128 - MAR Solutions - Managed Aquifer Recharge Strategies and Actions and the EU FPVII MARSOL. The event aimed at showcasing present experiences on MAR in Italy while at the same time starting a network among all the Institutions involved. In this contribution, we discuss the state of MAR application in Italy and summarize the outcomes of that event. In Italy aquifer recharge is traditionally applied unintentionally, by increasing riverbank filtration or because of excess irrigation. A certain interest for artificial recharge of aquifers arose at the end of the '70s and the beginning of the '80s and tests have been carried out in Tuscany, Veneto and Friuli Venezia Giulia. During the last years some projects on aquifer recharge were co-financed by the European Commission mainly through the LIFE program. Nearly all of them use the terminology of artificial recharge instead of MAR. They are: - TRUST (Tool for regional - scale assessment of groundwater storage improvement in adaptation to climate change, LIFE07 ENV/IT/000475; Marsala 2014); - AQUOR (Implementation of a water saving and artificial recharging participated strategy for the quantitative groundwater layer rebalance of the upper Vicenza's plain - LIFE 2010 ENV/IT/380; Mezzalira et al. 2014); - WARBO (Water re-born - artificial recharge: innovative technologies for the sustainable management of water resources, LIFE10 ENV/IT/000394; 2014). While the TRUST project dealt in general with aquifer recharge, AQUOR and WARBO focused essentially on small scale demonstration plants. Within the EU FPVII-ENV-2013 MARSOL project (Demonstrating Managed Aquifer Recharge as a Solution to Water Scarcity and Drought; 2014), a dedicated monitoring and decision support system is under development to manage recharge at a large scale

  5. Effects of variations in recharge on groundwater quality

    USGS Publications Warehouse

    Whittemore, D.O.; McGregor, K.M.; Marotz, G.A.

    1989-01-01

    The predominant regional effect of recharge on municipal groundwater quality in Kansas is the dilution of mineralized water in aquifers with relatively shallow water tables. The individual dissolved constituents contributing most to the water-quality variations are sulfate and chloride, and the calcium and sodium accompanying them, which are derived from the dissolution of evaporite minerals within the aquifer or from saline formation water in bedrock underlying the aquifer. The relationship between recharge and groundwater-quality variation can be quantified by associating certain climatic indices, especially the Palmer Drought Index, with quality observations. The response time of the maximum water-quality change relative to the occurrence of drought or substantial recharge ranges from a month to 3 years depending on the aquifer characteristics, and is generally proportional to the saturated thickness and specific yield. The response time is also affected by discharge to and recharge from nearby streams and by the well construction, particularly the placement of the screened interval, and pumping stress. ?? 1989.

  6. LOCALIZED RECHARGE INFLUENCES ON MTBE TRANSPORT AND WELL PLACEMENT CONSIDERATIONS

    EPA Science Inventory

    Vertical characterization of a gasoline release site at East Patchogue, New York showed that methyl tert-butyl ether (MTBE) and aromatic plumes "dived" as they passed beneath a sand pit. That this behavior was caused by aquifer recharge was shown by two pieces of evidence. Fir...

  7. Trench infiltration for managed aquifer recharge to permeable bedrock

    USGS Publications Warehouse

    Heilweil, V.M.; Watt, D.E.

    2011-01-01

    Managed aquifer recharge to permeable bedrock is increasingly being utilized to enhance resources and maintain sustainable groundwater development practices. One such target is the Navajo Sandstone, an extensive regional aquifer located throughout the Colorado Plateau of the western United States. Spreading-basin and bank-filtration projects along the sandstone outcrop's western edge in southwestern Utah have recently been implemented to meet growth-related water demands. This paper reports on a new cost-effective surface-infiltration technique utilizing trenches for enhancing managed aquifer recharge to permeable bedrock. A 48-day infiltration trench experiment on outcropping Navajo Sandstone was conducted to evaluate this alternative surface-spreading artificial recharge method. Final infiltration rates through the bottom of the trench were about 0.5 m/day. These infiltration rates were an order of magnitude higher than rates from a previous surface-spreading experiment at the same site. The higher rates were likely caused by a combination of factors including the removal of lower permeability soil and surficial caliche deposits, access to open vertical sandstone fractures, a reduction in physical clogging associated with silt and biofilm layers, minimizing viscosity effects by maintaining isothermal conditions, minimizing chemical clogging caused by carbonate mineral precipitation associated with algal photosynthesis, and diminished gas clogging associated with trapped air and biogenic gases. This pilot study illustrates the viability of trench infiltration for enhancing surface spreading of managed aquifer recharge to permeable bedrock. ?? 2010.

  8. Oxygen electrodes for rechargeable alkaline fuel cells. II

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.

    1990-01-01

    The primary objective of this program is the investigation and development of electrocatalysts and supports for the positive electrode of moderate temperature, single-unit, rechargeable alkaline fuel cells. Approximately six support materials and five catalyst materials have been identified to date for further development.

  9. Significance of the precambrian basement and late Cretaceous thrust nappes on the location of tertiary ore deposits in the Oquirrh Mountains, Utah

    USGS Publications Warehouse

    Tooker, Edwin W.

    2005-01-01

    buttress east of the Salt Lake area. The accretion suture along the north flank of the Uinta Anticline overlaps an earlier Precambrian east-west mobile zone, the Uinta trend (Erickson, 1976, Bryant and Nichols, 1988 and John, 1989), which extends westward across western Utah and into Nevada. A trace of the trend underlies the middle part of the Oquirrh Mountains. Its structure is recognized by disrupted Paleozoic stratigraphic units and fold and fault evidence of thrust faulting, intermittent local uplift and erosion, the alignment of Tertiary intrusives and associated ore deposits. Geologic readjustments along the trend continued intermittently through the Paleozoic, Cenozoic, Tertiary, and the development of clastic deposits along the shores of Pleistocene Lake Bonneville. Paleozoic sedimentary rocks were deposited on the craton platform shelf in westernmost Utah and eastern Nevada as the shelf subsided gradually and differentially. Debris was shed into two basins separated by the uplifted Uinta trend, the Oquirrh Basin on the south and Sublette Basin on the north. Sediments were derived from the craton to the east, the Antler orogenic zone on the west (Roberts, 1964), and locally from uplifted parts of the trend itself. Thick accumulations of clastic calcareous quartzite, shale, limestone, and dolomite of Lower and Upper Paleozoic ages are now exposed in the Oquirrh Mountains, the result of thrust faults. Evidence of decollement thrust faults in in the Wasatch Mountains during the Late Cretaceous Sevier orogeny, recognized by Baker and others (1949) and Crittenden (1961, is also recognized in the Oquirrh Mountains by Roberts and others (1965). During the late Cretaceous Sevier Orogeny, nappes were thrust sequentially along different paths from their western hinterland to the foreland. Five distinct nappes converged over the Uinta trend onto an uplifted west-plunging basement buttress east of the Oquirrh Mountains area: the Pass Canyon, Bingham,

  10. The UHP metamorphic Seve Nappe Complex of the Swedish Caledonides - a new occurrence of the microdiamond-bearing gneisses and their exhumation

    NASA Astrophysics Data System (ADS)

    Klonowska, Iwona; Janák, Marian; Majka, Jarosław; ‎ Froitzheim, Nikolaus; Gee, David G.

    2015-04-01

    The ultra-high pressure metamorphism (UHPM) in the Seve Nappe Complex of the Swedish Caledonides has been recently recognized within several lithologies including gneisses, eclogites and garnet pyroxenites (e.g. Janák et al. 2013, Klonowska et al. 2014a, Majka et al. 2014). Thermodynamic modelling and thermobarometric calculations indicate peak pressure conditions of >3GPa at c. 800-900°C (reaching the diamond stability field) for eclogites and garnet pyroxenites from northern Jämtland (e.g. Klonowska et al. 2014b). In addition to this, the first microdiamonds were found in paragneisses from the Snasahögarna Mt. in central Jämtland (Majka et al. 2014). Here we report a new discovery of microdiamond together with moissanite (SiC) from one of the world's most famous localities for thrusting, Mount Åreskutan, where long transport distances were recognized already in the 19th century (Törnebohm 1888). Garnet porphyroblasts in gneisses from the Åreskutan Mt. contain abundant mineral inclusions, mainly graphite, carbonates and quartz, together with fluid inclusions of CO2 concentrated in swarms. Among these inclusions three microdiamonds were found in two gneiss samples. In one of the samples moissanite was also discovered. Both minerals were identified by micro-Raman spectroscopy. In addition to these 'swarm' inclusions, biotite, kyanite, rutile, feldspars, zircon, monazite, ±phengite, ±muscovite, ±spinel, ±ilmenite, ±apatite occur in garnets. Phase equilibrium modelling for the phengite-bearing gneiss confirms its UHP history at temperatures of c. 800°C. Recent discoveries of UHP metamorphism within the Seve Nappe Complex derived from the Baltican outer margin (part of the Middle Allochthon) challenged us to present a new tectonic model incorporating exhumation of the deeply subducted continental rocks together with mantle lithosphere peridotites. Majka et al. (2014) introduced a new "under-pressure"-driven exhumation mechanism of rocks buried in

  11. Seismic source study of the Racha-Dzhava (Georgia) earthquake from aftershocks and broad-band teleseismic body-wave records: An example of active nappe tectonics

    USGS Publications Warehouse

    Fuenzalida, H.; Rivera, L.; Haessler, H.; Legrand, D.; Philip, H.; Dorbath, L.; McCormack, D.; Arefiev, S.; Langer, C.; Cisternas, A.

    1997-01-01

    -S oriented plane. Nappe tectonics has been identified as an important feature in the Caucasus, and the source mechanism is consistent with this observation. A hidden fault is present below the nappe, and no large surface breaks were observed due to the main shock. The epicentral region is characterized by sediments that are trapped between two crystalline basements: the Dzirula Massif, which crops out south of Chiatoura, and the Caucasus Main Range north of Oni. Most, if not all, of the rupture is controlled by the thrusting of overlapping, deformed and folded sediments over the Dzirula Massif. This event is another example of blind active faults, with the distinctive feature that the fault plane dips at a gentle angle. The Racha Range is one of the surface expressions of this blind thrust, and its growth is the consequence and evidence of similar earthquakes in the past.

  12. Syn- to post-orogenic exhumation of metamorphic nappes: Structure and thermobarometry of the western Attic-Cycladic metamorphic complex (Lavrion, Greece)

    NASA Astrophysics Data System (ADS)

    Scheffer, Christophe; Vanderhaeghe, Olivier; Lanari, Pierre; Tarantola, Alexandre; Ponthus, Léandre; Photiades, Adonis; France, Lydéric

    2016-05-01

    The Lavrion peninsula is located along the western boundary of the Attic-Cycladic metamorphic complex in the internal zone of the Hellenic orogenic belt. The nappe stack is well exposed and made, from top to bottom, of (i) a non-metamorphic upper unit composed of an ophiolitic melange, (ii) a middle unit mainly composed of the Lavrion schists in blueschist facies, (iii) and a basal unit mainly composed of the Kamariza schists affected by pervasive retrogression of the blueschist facies metamorphism in greenschist facies. The middle unit is characterized by a relatively steep-dipping foliation associated with isoclinal folds of weakly organized axial orientation. This foliation is transposed into a shallow-dipping foliation bearing a N-S trending lineation. The degree of transposition increases with structural depth and is particularly marked at the transition from the middle to the basal unit across a low-angle mylonitic to cataclastic detachment. The blueschist facies foliation of the Lavrion schists (middle unit) is underlined by high pressure phengite intergrown with chlorite. The Kamariza schists (basal unit) contains relics of the blueschist mineral paragenesis but is dominated by intermediate pressure phengite also intergrown with chlorite and locally with biotite. Electron probe micro-analyzer chemical mapping combined with inverse thermodynamic modeling (local multi-equilibrium) reveals distinct pressure-temperature conditions of crystallization of phengite and chlorite assemblages as a function of their structural, microstructural and microtextural positions. The middle unit is characterized by two metamorphic conditions grading from high pressure (M1, 9-13 kbar) to lower pressure (M2, 6-9 kbar) at a constant temperature of ca. 315 °C. The basal unit has preserved a first set of HP/LT conditions (M1-2, 8-11 kbar, 300 °C) partially to totally transposed-retrogressed into a lower pressure mineral assemblage (M3, 5-8.5 kbar) associated with a slight but

  13. Fragments of deeper parts of the hanging wall mantle preserved as orogenic peridotites in the central belt of the Seve Nappe Complex, Sweden

    NASA Astrophysics Data System (ADS)

    Clos, Frediano; Gilio, Mattia; van Roermund, Herman L. M.

    2014-04-01

    Formation conditions of olivine microstructures are investigated in the Kittelfjäll spinel peridotite (KSP), a fragment of lithospheric mantle which occurs as an isolated body within high grade metamorphic crustal rocks of the Seve Nappe Complex (SNC), southern Västerbotten, central Sweden. The KSP is an orogenic peridotite containing a well developed penetrative compositional layering, defined by highly depleted dunite with olivine Mg# (100 × Mg/Mg + Fe) of 92.0-93.5 and harzburgite with lower Mg# (91.0-92.5). Dunite is characterized by three contrasting olivine microstructures formed in response to different tectonometamorphic events: Coarse-grained, highly strained olivine porphyroclasts (M1) up to 20 cm long are surrounded by dynamically recrystallized olivine grains (M2) defining a characteristic olivine "foam" microstructure (grain size: 200-2000 μm). An olivine "mortar" (M3) microstructure (10-50 μm) forms a penetrative fabric element only in strongly localized, cm-to-m sized shear zones that crosscut earlier structures/foliations. Olivine fabric analysis in synergy, with mineralogical and chemical analyses, reveals that the KSP body represents old, possibly Archean, sub-continental lithospheric mantle that was crustally emplaced into the Caledonian tectonic edifice from the hanging wall mantle during exhumation of the subducted Seve Nappe Complex (Jämtlandian orogeny ~ 454 Ma). Olivine porphyroclasts (M1) grew at high temperature during dominant isobaric cooling after extensive polybaric melt extraction (> 40%) and subsequent refertilization. The onset of the early Caledonian deformation is interpreted to be related to the crustal emplacement of the KSP during eduction of the SNC. This phase is characterized by the development of the olivine M2 foam microstructure, formed at 650-830 °C/1-2 GPa by dislocation creep processes producing an E-type CPO's by the operation of the [100](001) and subordinate [001](100) slip systems with operating flow stress

  14. Possible silica gel in the Olive Fault, Naukluft Nappe Complex, Namibia: A geologic record of dynamic weakening in faults during continental orogenesis

    NASA Astrophysics Data System (ADS)

    Faber, C.; Rowe, C. D.; Miller, J. A.; Backeberg, N.; Sylvester, F.

    2009-12-01

    The apparently low frictional strength of faults during earthquake slip is not sufficiently well explained. Dynamic weakening has been observed in recent laboratory experiments at seismic slip rates, even if materials are strong at slow slip rates. Di Toro et al. (2004) performed experiments on crystalline rocks at slip rates of 1m/s and observed frictional strength drops to near zero. Examination of the slip surface revealed an amorophous silica had formed during fast slip and interpreted this as a solidified silica gel. If similar silica gel forms during earthquakes, and solidifies to amorphous silica, it would be expected to slowly crystallize over time. Ujiie et al (2007) reported a microcrystalline silica fault vein from the Shimanto Complex (Japan) which contains colloidal microspheres of silica, consistent with its origin as a silica gel. This vein may have been created during seismic slip, although other explanations are possible. No other natural examples of this potentially important coseismic weakening mechanism have been reported. To investigate whether silica gel actually forms during seismic slip, it will be necessary to discover and fully characterize additional natural examples. The Naukluft Nappe Complex in central Namibia is a foreland thrust stack at the distal southern margin of the Pan-African Damara Orogen (active at ~ 550Ma). A fault vein of microcrystalline silica has been found in an intra-nappe thrust fault . The vein occurs as a mostly continuous, planar, 0.1-1.0cm-thick fault vein within dolomite breccias of the Olive Fault. There are no other veins of silica associated with the fault. The hanging wall and footwall are dolomite and calcareous shales, respectively. The layer is petrographically similar to the microcrystalline silica described by Ujiie et al. (2007). The silica layer is purple-blue to white in color cathodoluminescence, in contrast to the bright turquoise typical of quartz. Although X-ray diffraction spectra show only

  15. The recent fault kinematics in the westernmost part of the Getic nappe system (Eastern Serbia): Evidence from fault slip and focal mechanism data

    NASA Astrophysics Data System (ADS)

    Mladenović, Ana; Trivić, Branislav; Antić, Milorad; Cvetković, Vladica; Pavlović, Radmila; Radovanović, Slavica; Fügenschuh, Bernhard

    2014-04-01

    In this study we performed a calculation of the tectonic stress tensor based on fault slip data and all available focal mechanisms in order to determine the principal stress axes and the recent tectonic regime of the westernmost unit of the Getic nappe system (Gornjak-Ravanica Zone, Eastern Serbia). The study is based on a combined dataset involving paleostress analyses, the inversion of focal mechanisms and remote sensing. The results show dominant strike-slip kinematics with the maximal compression axis oriented NNE-SSW. This is compatible with a combined northward motion and counterclockwise rotation of the Adria plate as the controlling factor. However, the local stress field is also shown to be of great importance and is superimposed on the far-field stress. We managed to distinguish three areas with distinct seismic activity. The northern part of the research area is characterized by transtensional tectonics, possibly under the influence of the extension in the areas situated more to the northeast. The central and seismically most active part is dominated by strike-slip tectonics whereas the southern area is slightly transpressional, possibly under the influence of the rigid Moesian Platform situated to the east of the research area. The dominant active fault systems are oriented N-S (to NE-SW) and NW-SE and they occur as structures of either regional or local significance. Regional structures are active in the northern and central part of the study area, while the active fault systems in the southern part are marked as locally important. This study suggests that seismicity of this area is controlled by the release of accumulated stress at local accommodation zones which are favourably oriented in respect to the active regional stress field.

  16. Groundwater recharge measurements in gravel sandy sediments with monolith lysimeter

    NASA Astrophysics Data System (ADS)

    Bracic Zeleznik, Branka; Souvent, Petra; Cencur Curk, Barbara; Zupanc, Vesna

    2013-04-01

    Ljubljana field aquifer is recharging through precipitation and the river Sava, which has the snow-rain flow regime. The sediments of the aquifer have high permeability and create fast flow as well as high regeneration of the dynamic reserves of the Ljubljana field groundwater resource. Groundwater recharge is vulnerable to climate change and it is very important for drinking water supply management. Water stored in the soil and less permeable layers is important for water availability under extreme weather conditions. Measurements of water percolation through the vadose zone provide important input for groundwater recharge assessment and estimation of contaminant migration from land surface to the groundwater. Knowledge of the processes governing groundwater recharge in the vadose zone is critical to understanding the overall hydrological cycle and quantifying the links between land uses and groundwater quantity and quality. To improve the knowledge on water balance for Ljubljana field aquifer we establish a lysimeter for measurements of processes in unsaturated zone in well field Kleče. The type of lysimeter is a scientific lysimeter designed to solve the water balance equation by measuring the mass of the lysimeter monolith as well as that of outflow tank with high accuracy and high temporal resolution. We evaluated short period data, however the chosen month demonstrates weather extremes of the local climate - relatively dry periods, followed by high precipitation amount. In time of high water usage of vegetation only subsequent substantial precipitation events directly results in water flow towards lower layers. At the same time, gravely layers of the deeper parts of the unsaturated zone have little or no capacity for water retention, and in the event that water line leaves top soil, water flow moves downwards fairly quickly. On one hand this confirms high recharge capacity of Ljubljana field aquifer from precipitation on green areas; on the other hand it

  17. Global transpiration, recharge and runoff tracked with stable isotopes

    NASA Astrophysics Data System (ADS)

    Jasechko, S.

    2015-12-01

    The transformations of precipitation into soil-, ground- or stream-water constitute fundamental components of the hydrologic cycle. Hydrometric data are well suited to track propagations of pressures through the landscape, but tell us little about the transport of water itself. Conversely, isotopic data track movements of molecules, providing quantitative insights into subsurface processes. This presentation reviews recent uses of isotopic data to quantify the velocity, storage and mixing of precipitation as it flushes into plants (1. transpiration), aquifers (2. recharge) and streams (3. runoff). (1) Plant transpiration comprises the largest flux of fresh water from the continents, exceeding global river flows by a factor of ~1.5. Mounting evidence suggests that water used by plants is poorly connected to water flowing into streams and aquifers, contrasting most earth system model parameterizations. (2) This partitioning of precipitation into "blue" (recharge, runoff) and "green" (transpiration) water storages is further evidenced by relating precipitation and groundwater isotope contents. Global precipitation-groundwater isotope data show that snowmelt pulses (extratropics) and intensive rainfall (tropics) lead to disproportionately large groundwater recharge fluxes—that is, recharge/precipitation ratios exceeding the local annual average. Across the low latitudes, these results mean that the ongoing intensification of precipitation brought on by global warming may serve to promote groundwater recharge in the tropics, where, by 2050, half of the world's population is projected to live. (3) This presentation concludes by relating precipitation and streamflow isotope contents to show that ~1/3 of global river discharges are generated by precipitation that reaches the stream in less than 3 months (i.e., "young water" in rivers). Substantial and pervasive young, month(s)-old water in global rivers means that biogeochemical processes taking place in the critical

  18. Groundwater recharge dynamics in unsaturated fractured chalk: a case study

    NASA Astrophysics Data System (ADS)

    Cherubini, Claudia; Pastore, Nicola; Giasi, Concetta I.; Allegretti, Nicolaetta M.

    2016-04-01

    The heterogeneity of the unsaturated zone controls its hydraulic response to rainfall and the extent to which pollutants are delayed or attenuated before reaching groundwater. It plays therefore a very important role in the recharge of aquifers and the transfer of pollutants because of the presence of temporary storage zones and preferential flows. A better knowledge of the physical processes in the unsaturated zone would allow an improved assessment of the natural recharge in a heterogeneous aquifer and of its vulnerability to surface-applied pollution. The case study regards the role of the thick unsaturated zone of the Cretaceous chalk aquifer in Picardy (North of France) that controls the hydraulic response to rainfall. In the North Paris Basin, much of the recharge must pass through a regional chalk bed that is composed of a porous matrix with embedded fractures. Different types of conceptual models have been formulated to explain infiltration and recharge processes in the unsaturated fractured rock. The present study analyses the episodic recharge in fractured Chalk aquifer using the kinematic diffusion theory to predict water table fluctuation in response to rainfall. From an analysis of the data, there is the evidence of 1) a seasonal behavior characterized by a constant increase in the water level during the winter/spring period and a recession period, 2) a series of episodic behaviors during the summer/autumn. Kinematic diffusion models are useful for predict preferential fluxes and dynamic conditions. The presented approach conceptualizes the unsaturated flow as a combination of 1) diffusive flow refers to the idealized portion of the pore space of the medium within the flow rate is driven essentially by local gradient of potential; 2) preferential flow by which water moves across macroscopic distances through conduits of macropore length.

  19. Enhanced recharge and karst, Edwards aquifer, south central Texas

    SciTech Connect

    Hammond, W.W. Jr. . Center for Water Research)

    1993-02-01

    Enhanced recharge is a water management strategy which can add significant quantities of ground water to the available water resources of the San Antonio region by utilizing the immense storage capacity of the unconfined zone of the Edwards aquifer. The Edwards aquifer presently is the sole source of water for a population of over 1,200,000, meeting public supply, industrial, and irrigation demands over a wide area of south central Texas. Valdina Farms Sinkhole is located adjacent to Seco Creek in Medina County and is in the recharge zone of the aquifer. Initial studies indicated that the sinkholes was capable of taking flood flows from Seco Creek and functioning as a recharge structure. Stream channels in the cavern system associated with Valdina Farms Sinkhole were incised into cave deposits and flood debris was present in the caverns at some distance from the sinkhole. Chemical analyses of samples of water from the cave and from nearby wells showed nitrate concentrations that decreased with distance from the cavern. Gradient of the potentiometric surface in the vicinity of the cave was very low, indicating high values of hydraulic conductivity for the aquifer. Based on evidence from these field studies a dam was constructed in 1982 on Seco Creek and a flood diversion channel was excavated to the sinkhole. Reservoir capacity is 2 acre-feet and design recharge rate is 3.8-6.7 m[sup 3]/sec. Annual recharge at the sinkhole has varied from 0 during periods of low runoff to 12,915 acre-feet.

  20. Quantifying Groundwater Recharge During Dynamic Seasonality in Cold Climates

    NASA Astrophysics Data System (ADS)

    Pasha, E.; Rudolph, D. L.

    2015-12-01

    Estimating groundwater recharge in cold climates, during periods of dynamic seasonality such as winter and spring freshets is challenging due to subsurface heterogeneities and the complexity of vadose zone processes under partially frozen conditions. In order to obtain robust recharge estimates, numerical models simulating these complex processes need to be based on reliable parameter estimates and closely calibrated to field observations. This study focuses on quantifying recharge under an ephemeral stream that develops in the vicinity of a municipal well field during spring and winter freshets at a site in Southern Ontario. Temperature and moisture content profiles in the vadose zone were obtained during the 2015 spring melt at three different locations, using a variety of hydrogeological instruments. Temperature thermisters and Tid-Bit transducers were both installed at 15-30 cm spacings to the depth of the water table in order to compare and calibrate the results. Similarly, Time Domain Reflectometry probes were placed to the depth of the water table and the results were calibrated to daily moisture content readings taken with a Neutron Probe. Water table fluctuations were monitored and regular water samples were taken for analysis of geochemistry and isotope fractionation. This data provided the boundary conditions for the numerical model (Hydrus 1D) and allowed for its calibration and validation. Regions of rapid infiltration were observed at the site, as well as steep temperature gradients that could be used as a tracer for estimating recharge in cold climates. The geochemistry and isotope fractionation results provided support of surface water groundwater interaction within event based time periods predicted by the numerical models. Furthermore, the surface water samples were found to have high concentrations of microbial indicator species, and therefore the intense recharge phenomena observed at the site has significant implications to groundwater

  1. Grundlagen des Tissue Engineering

    NASA Astrophysics Data System (ADS)

    Mayer, Jörg; Blum, Janaki; Wintermantel, Erich

    Die Organtransplantation stellt eine verbreitete Therapie dar, um bei krankheitsoder unfallbedingter Schädigung eines Organs die Gesamtheit seiner Funktionen wieder herzustellen, indem es durch ein Spenderorgan ersetzt wird. Organtransplantationen werden für die Leber, die Niere, die Lunge, das Herz oder bei schweren grossflächigen Verbrennungen der Haut vorgenommen. Der grosse apparative, personelle und logistische Aufwand und die Risiken der Transplantationschirurgie (Abstossungsreaktionen) sowie die mangelnde Verfügbarkeit von immunologisch kompatiblen Spenderorganen führen jedoch dazu, dass der Bedarf an Organtransplantaten nur zu einem sehr geringen Teil gedeckt werden kann. Sind Spenderorgane nicht verfügbar, können in einzelnen Fällen lebenswichtige Teilfunktionen, wie beispielsweise die Filtrationsfunktion der Niere durch die Blutreinigung mittels Dialyse ersetzt oder, bei mangelnder Funktion der Bauchspeicheldrüse (Diabetes), durch die Verabreichung von Insulin ein normaler Zustand des Gesamtorganismus auch über Jahre hinweg erhalten werden. Bei der notwendigen lebenslangen Anwendung apparativer oder medikamentöser Therapie können für den Patienten jedoch häufig schwerwiegende, möglicherweise lebensverkürzende Nebenwirkungen entstehen. Daher werden in der Forschung Alternativen gesucht, um die Funktionen des ausgefallenen Organs durch die Implantation von Zellen oder in vitro gezüchteten Geweben möglichst umfassend wieder herzustellen. Dies erfordert biologisch aktive Implantate, welche die für den Stoffwechsel des Organs wichtigen Zellen enthalten und einen organtypischen Stoffwechsel entfalten.

  2. Migration of recharge waters downgradient from the Santa Catalina Mountains into the Tucson basin aquifer, Arizona, USA

    NASA Astrophysics Data System (ADS)

    Cunningham, Erin E. B.; Long, Austin; Eastoe, Chris; Bassett, R. L.

    Aquifers in the arid alluvial basins of the southwestern U.S. are recharged predominantly by infiltration from streams and playas within the basins and by water entering along the margins of the basins. The Tucson basin of southeastern Arizona is such a basin. The Santa Catalina Mountains form the northern boundary of this basin and receive more than twice as much precipitation (ca. 700mm/year) as does the basin itself (ca. 300mm/year). In this study environmental isotopes were employed to investigate the migration of precipitation basinward through shallow joints and fractures. Water samples were obtained from springs and runoff in the Santa Catalina Mountains and from wells in the foothills of the Santa Catalina Mountains. Stable isotopes (δD and δ18O) and thermonuclear-bomb-produced tritium enabled qualitative characterization of flow paths and flow velocities. Stable-isotope measurements show no direct altitude effect. Tritium values indicate that although a few springs and wells discharge pre-bomb water, most springs discharge waters from the 1960s or later. Résumé La recharge des aquifères des bassins alluviaux arides du sud-ouest des États-Unis est assurée surtout à partir des lits des cours d'eau et des playas dans les bassins, ainsi que par l'eau entrant à la bordure de ces bassins. Le bassin du Tucson, dans le sud-est de l'Arizona, est l'un de ceux-ci. La chaîne montagneuse de Santa Catalina constitue la limite nord de ce bassin et reçoit plus de deux fois plus de précipitations (environ 700mm/an) que le bassin (environ 300mm/an). Dans cette étude, les isotopes du milieu ont été utilisés pour analyser le déplacement de l'eau de pluie vers le bassin au travers des fissures et des fractures proches de la surface. Des échantillons d'eau ont été prélevés dans les sources et dans l'écoulement de surface de la chaîne montagneuse et dans des puits au pied de la chaîne. Les isotopes stables (δD et δ18O) et le tritium d

  3. Monitoring induced denitrification in an artificial aquifer recharge system.

    NASA Astrophysics Data System (ADS)

    Grau-Martinez, Alba; Torrentó, Clara; Folch, Albert; Domènech, Cristina; Otero, Neus; Soler, Albert

    2014-05-01

    As demands on groundwater increase, artificial recharge is becoming a common method for enhancing groundwater supply. The Llobregat River is a strategic water supply resource to the Barcelona metropolitan area (Catalonia, NE Spain). Aquifer overexploitation has leaded to both a decrease of groundwater level and seawater intrusion, with the consequent deterioration of water quality. In the middle section of the aquifer, in Sant Vicenç del Horts, decantation and infiltration ponds recharged by water from the Llobregat River (highly affected from wastewater treatment plant effluents), were installed in 2007, in the framework of the ENSAT Life+ project. At the bottom of the infiltration pond, a vegetal compost layer was installed to promote the growth of bacteria, to induce denitrification and to create favourable conditions for contaminant biodegradation. This layer consists on a mixture of compost, aquifer material, clay and iron oxide. Understanding the fate of contaminants, such as nitrate, during artificial aquifer recharge is required to evaluate the impact of artificial recharge in groundwater quality. In order to distinguish the source of nitrate and to evaluate the capability of the organic reactive layer to induce denitrification, a multi-isotopic approach coupled with hydrogeochemical data was performed. Groundwater samples, as well as river samples, were sampled during artificial and natural recharge periods. The isotopic analysis included: δ15N and δ18O of dissolved nitrate, δ34S and δ18O of dissolved sulphate, δ13C of dissolved inorganic carbon, and δ2H and δ18O of water. Dissolved nitrate isotopic composition (δ15NNO3 from +9 to +21 o and δ18ONO3 from +3 to +16 ) demonstrated that heterotrophic denitrification induced by the reactive layer was taking place during the artificial recharge periods. An approximation to the extent of nitrate attenuation was calculated, showing a range between 95 and 99% or between 35 and 45%, by using the extreme

  4. Transient,spatially-varied recharge for groundwater modeling

    NASA Astrophysics Data System (ADS)

    Assefa, Kibreab; Woodbury, Allan

    2013-04-01

    This study is aimed at producing spatially and temporally varying groundwater recharge for transient groundwater modeling in a pilot watershed in the North Okanagan, Canada. The recharge modeling is undertaken by using a Richard's equation based finite element code (HYDRUS-1D) [Simunek et al., 2002], ArcGISTM [ESRI, 2011], ROSETTA [Schaap et al., 2001], in situ observations of soil temperature and soil moisture and a long term gridded climate data [Nielsen et al., 2010]. The public version of HYDUS-1D [Simunek et al., 2002] and another beta version with a detailed freezing and thawing module [Hansson et al., 2004] are first used to simulate soil temperature, snow pack and soil moisture over a one year experimental period. Statistical analysis of the results show both versions of HYDRUS-1D reproduce observed variables to the same degree. Correlation coefficients for soil temperature simulation were estimated at 0.9 and 0.8, at depths of 10 cm and 50 cm respectively; and for soil moisture, 0.8 and 0.6 at 10 cm and 50 cm respectively. This and other standard measures of model performance (root mean square error and average error) showed a promising performance of the HYDRUS-1D code in our pilot watershed. After evaluating model performance using field data and ROSETTA derived soil hydraulic parameters, the HYDRUS-1D code is coupled with ArcGISTM to produce spatially and temporally varying recharge maps throughout the Deep Creek watershed. Temporal and spatial analysis of 25 years daily recharge results at various representative points across the study watershed reveal significant temporal and spatial variations; average recharge estimated at 77.8 ± 50.8mm /year. This significant variation over the years, caused by antecedent soil moisture condition and climatic condition, illustrates the common flaw of assigning a constant percentage of precipitation throughout the simulation period. Groundwater recharge modeling has previously been attempted in the Okanagan Basin

  5. Transient, spatially-varied recharge for groundwater modeling

    NASA Astrophysics Data System (ADS)

    Assefa, K.; Woodbury, A. D.

    2012-12-01

    This study is aimed at producing spatially and temporally varying groundwater recharge for transient groundwater modeling in a pilot watershed in the North Okanagan, Canada. The recharge modeling is undertaken by using a Richard's equation based finite element code (HYDRUS-1D) [Simunek et al., 2002], ArcGISTM [ESRI, 2011], ROSETTA [Schaap et al., 2001], in situ observations of soil temperature and soil moisture and a long term gridded climate data [Nielsen et al., 2010]. The public version of HYDUS-1D [Simunek et al., 2002] and another beta version with a detailed freezing and thawing module [Hansson et al., 2004] are first used to simulate soil temperature, snow pack and soil moisture over a one year experimental period. Statistical analysis of the results show both versions of HYDRUS-1D reproduce observed variables to the same degree. Correlation coefficients for soil temperature simulation were estimated at 0.9 and 0.8, at depths of 10 cm and 50 cm respectively; and for soil moisture, 0.8 and 0.6 at 10 cm and 50 cm respectively. This and other standard measures of model performance (root mean square error and average error) showed a promising performance of the HYDRUS-1D code in our pilot watershed. After evaluating model performance using field data and ROSETTA derived soil hydraulic parameters, the HYDRUS-1D code is coupled with ArcGISTM to produce spatially and temporally varying recharge maps throughout the Deep Creek watershed. Temporal and spatial analysis of 25 years daily recharge results at various representative points across the study watershed reveal significant temporal and spatial variations; average recharge estimated at 77.8 ± 50.8mm /year. This significant variation over the years, caused by antecedent soil moisture condition and climatic condition, illustrates the common flaw of assigning a constant percentage of precipitation throughout the simulation period. Groundwater recharge modeling has previously been attempted in the Okanagan Basin

  6. Reticulation des fibres lignocellulosiques

    NASA Astrophysics Data System (ADS)

    Landrevy, Christel

    Pour faire face à la crise économique la conception de papier à valeur ajoutée est développée par les industries papetières. Le but de se projet est l'amélioration des techniques actuelles de réticulation des fibres lignocellulosiques de la pâte à papier visant à produire un papier plus résistant. En effet, lors des réactions de réticulation traditionnelles, de nombreuses liaisons intra-fibres se forment ce qui affecte négativement l'amélioration anticipée des propriétés physiques du papier ou du matériau produit. Pour éviter la formation de ces liaisons intra-fibres, un greffage sur les fibres de groupements ne pouvant pas réagir entre eux est nécessaire. La réticulation des fibres par une réaction de « click chemistry » appelée cycloaddition de Huisgen entre un azide et un alcyne vrai, catalysée par du cuivre (CuAAC) a été l'une des solutions trouvée pour remédier à ce problème. De plus, une adaptation de cette réaction en milieux aqueux pourrait favoriser son utilisation en milieu industriel. L'étude que nous désirons entreprendre lors de ce projet vise à optimiser la réaction de CuAAC et les réactions intermédiaires (propargylation, tosylation et azidation) sur la pâte kraft, en milieu aqueux. Pour cela, les réactions ont été adaptées en milieu aqueux sur la cellulose microcristalline afin de vérifier sa faisabilité, puis transférée à la pâte kraft et l'influence de différents paramètres comme le temps de réaction ou la quantité de réactifs utilisée a été étudiée. Dans un second temps, une étude des différentes propriétés conférées au papier par les réactions a été réalisée à partir d'une série de tests papetiers optiques et physiques. Mots Clés Click chemistry, Huisgen, CuAAC, propargylation, tosylation, azidation, cellulose, pâte kraft, milieu aqueux, papier.

  7. Classification of ground-water recharge potential in three parts of Santa Cruz County, California

    USGS Publications Warehouse

    Muir, K.S.; Johnson, Michael J.

    1979-01-01

    Ground-water recharge potential was classified in the Santa Cruz coastal area, North-central area, and Soquel-Aptos area in Santa Cruz County, Calif., for three data elements that affect recharge; slope, soils, and geology. Separate numerical maps for each element were composited into a single numerical map using a classification system that ranked the numbers into areas of good , fair, and poor recharge potential. Most of the Santa Cruz coastal area and the Norht-central area have a poor recharge potential, and much of the Soquel-Aptos area has a good to fair recharge potential. (Kosco-USGS)

  8. Recharge Estimation Using Water, Chloride and Isotope Mass Balances

    NASA Astrophysics Data System (ADS)

    Dogramaci, S.; Firmani, G.; Hedley, P.; Skrzypek, G.; Grierson, P. F.

    2014-12-01

    Discharge of surplus mine water into ephemeral streams may elevate groundwater levels and alter the exchange rate between streams and underlying aquifers but it is unclear whether volumes and recharge processes are within the range of natural variability. Here, we present a case study of an ephemeral creek in the semi-arid subtropical Hamersley Basin that has received continuous mine discharge for more than five years. We used a numerical model coupled with repeated measurements of water levels, chloride concentrations and the hydrogen and oxygen stable isotope composition (δ2H and δ18O) to estimate longitudinal evapotranspiration and recharge rates along a 27 km length of Weeli Wolli Creek. We found that chloride increased from 74 to 120 mg/L across this length, while δ18O increased from -8.24‰ to -7.00‰. Groundwater is directly connected to the creek for the first 13 km and recharge rates are negligible. Below this point, the creek flows over a highly permeable aquifer and water loss by recharge increases to a maximum rate of 4.4 mm/d, which accounts for ~ 65% of the total water discharged to the creek. Evapotranspiration losses account for the remaining ~35%. The calculated recharge from continuous flow due to surplus water discharge is similar to that measured for rainfall-driven flood events along the creek. Groundwater under the disconnected section of the creek is characterised by a much lower Cl concentration and more depleted δ18O value than mining discharge water but is similar to flood water generated by large episodic rainfall events. Our results suggest that the impact of recharge from continuous flow on the creek has not extended beyond 27 km from the discharge point. Our approach using a combination of hydrochemical and isotope methods coupled with classical surface flow hydraulic modelling allowed evaluation of components of water budget otherwise not possible in a highly dynamic system that is mainly driven by infrequent but large episodic

  9. The spatial and temporal variability of groundwater recharge in a forested basin in northern Wisconsin

    USGS Publications Warehouse

    Dripps, W.R.; Bradbury, K.R.

    2010-01-01

    Recharge varies spatially and temporally as it depends on a wide variety of factors (e.g. vegetation, precipitation, climate, topography, geology, and soil type), making it one of the most difficult, complex, and uncertain hydrologic parameters to quantify. Despite its inherent variability, groundwater modellers, planners, and policy makers often ignore recharge variability and assume a single average recharge value for an entire watershed. Relatively few attempts have been made to quantify or incorporate spatial and temporal recharge variability into water resource planning or groundwater modelling efforts. In this study, a simple, daily soil-water balance model was developed and used to estimate the spatial and temporal distribution of groundwater recharge of the Trout Lake basin of northern Wisconsin for 1996-2000 as a means to quantify recharge variability. For the 5 years of study, annual recharge varied spatially by as much as 18 cm across the basin; vegetation was the predominant control on this variability. Recharge also varied temporally with a threefold annual difference over the 5-year period. Intra-annually, recharge was limited to a few isolated events each year and exhibited a distinct seasonal pattern. The results suggest that ignoring recharge variability may not only be inappropriate, but also, depending on the application, may invalidate model results and predictions for regional and local water budget calculations, water resource management, nutrient cycling, and contaminant transport studies. Recharge is spatially and temporally variable, and should be modelled as such. Copyright ?? 2009 John Wiley & Sons, Ltd.

  10. A new method for estimating recharge to unconfined aquifers using differential river gauging.

    PubMed

    McCallum, Andrew M; Andersen, Martin S; Acworth, R Ian

    2014-01-01

    In semiarid and arid environments, leakage from rivers is a major source of recharge to underlying unconfined aquifers. Differential river gauging is widely used to estimate the recharge. However, the methods commonly applied are limited in that the temporal resolution is event-scale or longer. In this paper, a novel method is presented for quantifying both the total recharge volume for an event, and variation in recharge rate during an event from hydrographs recorded at the upstream and downstream ends of a river reach. The proposed method is applied to river hydrographs to illustrate the method steps and investigate recharge processes occurring in a sub-catchment of the Murray Darling Basin (Australia). Interestingly, although it is the large flood events which are commonly assumed to be the main source of recharge to an aquifer, our analysis revealed that the smaller flow events were more important in providing recharge.

  11. Managed Aquifer Recharge in Italy: present and prospects.

    NASA Astrophysics Data System (ADS)

    Rossetto, Rudy

    2015-04-01

    On October the 3rd 2014, a one-day Workshop on Managed Aquifer Recharge (MAR) experiences in Italy took place at the GEOFLUID fair in Piacenza. It was organized within the framework of the EIP AG 128 - MAR Solutions - Managed Aquifer Recharge Strategies and Actions and the EU FPVII MARSOL. The event aimed at showcasing present experiences on MAR in Italy while at the same time starting a network among all the Institutions involved. In this contribution, we discuss the state of MAR application in Italy and summarize the outcomes of that event. In Italy aquifer recharge is traditionally applied unintentionally, by increasing riverbank filtration or because of excess irrigation. A certain interest for artificial recharge of aquifers arose at the end of the '70s and the beginning of the '80s and tests have been carried out in Tuscany, Veneto and Friuli Venezia Giulia. During the last years some projects on aquifer recharge were co-financed by the European Commission mainly through the LIFE program. Nearly all of them use the terminology of artificial recharge instead of MAR. They are: - TRUST (Tool for regional - scale assessment of groundwater storage improvement in adaptation to climate change, LIFE07 ENV/IT/000475; Marsala 2014); - AQUOR (Implementation of a water saving and artificial recharging participated strategy for the quantitative groundwater layer rebalance of the upper Vicenza's plain - LIFE 2010 ENV/IT/380; Mezzalira et al. 2014); - WARBO (Water re-born - artificial recharge: innovative technologies for the sustainable management of water resources, LIFE10 ENV/IT/000394; 2014). While the TRUST project dealt in general with aquifer recharge, AQUOR and WARBO focused essentially on small scale demonstration plants. Within the EU FPVII-ENV-2013 MARSOL project (Demonstrating Managed Aquifer Recharge as a Solution to Water Scarcity and Drought; 2014), a dedicated monitoring and decision support system is under development to manage recharge at a large scale

  12. Recharging behavior of nitrogen-centers in ZnO

    SciTech Connect

    Philipps, Jan M. Meyer, Bruno K.; Hofmann, Detlev M.; Stehr, Jan E.; Buyanova, Irina; Tarun, Marianne C.; McCluskey, Matthew D.

    2014-08-14

    Electron Paramagnetic Resonance was used to study N{sub 2}-centers in ZnO, which show a 5-line spectrum described by the hyperfine interaction of two nitrogen nuclei (nuclear spin I = 1, 99.6% abundance). The recharging of this center exhibits two steps, a weak onset at about 1.4 eV and a strongly increasing signal for photon energies above 1.9 eV. The latter energy coincides with the recharging energy of N{sub O} centers (substitutional nitrogen atoms on oxygen sites). The results indicate that the N{sub 2}-centers are deep level defects and therefore not suitable to cause significant hole-conductivity at room temperature.

  13. Hybrid system for rechargeable magnesium battery with high energy density

    PubMed Central

    Chang, Zheng; Yang, Yaqiong; Wang, Xiaowei; Li, Minxia; Fu, Zhengwen; Wu, Yuping; Holze, Rudolf

    2015-01-01

    One of the main challenges of electrical energy storage (EES) is the development of environmentally friendly battery systems with high safety and high energy density. Rechargeable Mg batteries have been long considered as one highly promising system due to the use of low cost and dendrite-free magnesium metal. The bottleneck for traditional Mg batteries is to achieve high energy density since their output voltage is below 2.0 V. Here, we report a magnesium battery using Mg in Grignard reagent-based electrolyte as the negative electrode, a lithium intercalation compound in aqueous solution as the positive electrode, and a solid electrolyte as a separator. Its average discharge voltage is 2.1 V with stable discharge platform and good cycling life. The calculated energy density based on the two electrodes is high. These findings open another door to rechargeable magnesium batteries. PMID:26173624

  14. Zinc electrode and rechargeable zinc-air battery

    DOEpatents

    Ross, Jr., Philip N.

    1989-01-01

    An improved zinc electrode is disclosed for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed which utilizes the improved zinc electrode and further includes an alkaline electrolyte within said battery circulating through the passageways in the zinc electrode and an external electrolyte circulation means which has an electrolyte reservoir external to the battery case including filter means to filter solids out of the electrolyte as it circulates to the external reservoir and pump means for recirculating electrolyte from the external reservoir to the zinc electrode.

  15. Evaluation of slurry characteristics for rechargeable lithium-ion batteries

    SciTech Connect

    Cho, Ki Yeon; Kwon, Young Il; Youn, Jae Ryoun; Song, Young Seok

    2013-08-01

    Graphical abstract: - Highlights: • Lithium-ion battery slurries are prepared for rechargeable batteries. • The dispersion state of slurry constituents is identified. • Thermal, morphological, rheological, and electrical properties of slurries are analyzed. - Abstract: A multi-component slurry for rechargeable batteries is prepared by dispersing LiCoO{sub 2}, conductive additives, and polymeric binders in a solvent. The physical properties, including rheological, morphological, electrical, and spectroscopic features of battery slurries are investigated. The relationship between the measured physical properties and the internal structure of the slurry is analyzed. It is found that the rheological behavior of the slurry is determined by the interaction of active materials and binding materials (e.g., network structure) and that the dispersion state of conductive additives (e.g., agglomeration) also depends on the binder–carbon interaction.

  16. Water quality management of aquifer recharge using advanced tools.

    PubMed

    Lazarova, Valentina; Emsellem, Yves; Paille, Julie; Glucina, Karl; Gislette, Philippe

    2011-01-01

    Managed aquifer recharge (MAR) with recycled water or other alternative resources is one of the most rapidly growing techniques that is viewed as a necessity in water-short areas. In order to better control health and environmental effects of MAR, this paper presents two case studies demonstrating how to improve water quality, enable reliable tracing of injected water and better control and manage MAR operation in the case of indirect and direct aquifer recharge. Two water quality management strategies are illustrated on two full-scale case studies, including the results of the combination of non conventional and advanced technologies for water quality improvement, comprehensive sampling and monitoring programs including emerging pollutants, tracer studies using boron isotopes and integrative aquifer 3D GIS hydraulic and hydrodispersive modelling.

  17. Novel electrolyte chemistries for Mg-Ni rechargeable batteries.

    SciTech Connect

    Garcia-Diaz, Brenda; Kane, Marie; Au, Ming

    2010-10-01

    Commercial hybrid electric vehicles (HEV) and battery electric vehicles (BEV) serve as means to reduce the nation's dependence on oil. Current electric vehicles use relatively heavy nickel metal hydride (Ni-MH) rechargeable batteries. Li-ion rechargeable batteries have been developed extensively as the replacement; however, the high cost and safety concerns are still issues to be resolved before large-scale production. In this study, we propose a new highly conductive solid polymer electrolyte for Mg-Ni high electrochemical capacity batteries. The traditional corrosive alkaline aqueous electrolyte (KOH) is replaced with a dry polymer with conductivity on the order of 10{sup -2} S/cm, as measured by impedance spectroscopy. Several potential novel polymer and polymer composite candidates are presented with the best-performing electrolyte results for full cell testing and cycling.

  18. Development of Carbon Anode for Rechargeable Lithium Cells

    NASA Technical Reports Server (NTRS)

    Huang, C. -K.; Surampudi, S.; Halpert, G.

    1994-01-01

    Conventionally, rechargeable lithium cells employ a pure lithium anode. To overcome problems associated with the pure lithium electrode, it has been proposed to replace the conventional electrode with an alternative material having a greater stability with respect to the cell electrolytes. For this reason, several graphitic and coke based carbonaceous materials were evaluated as candidate anode materials...In this paper, we summarize the results of the studies on Li-ion cell development.

  19. Scale effects of hydrostratigraphy and recharge zonation on base flow

    USGS Publications Warehouse

    Juckem, P.F.; Hunt, R.J.; Anderson, M.P.

    2006-01-01

    Uncertainty regarding spatial variations of model parameters often results in the simplifying assumption that parameters are spatially uniform. However, spatial variability may be important in resource assessment and model calibration. In this paper, a methodology is presented for estimating a critical basin size, above which base flows appear to be relatively less sensitive to the spatial distribution of recharge and hydraulic conductivity, and below which base flows are relatively more sensitive to this spatial variability. Application of the method is illustrated for a watershed that exhibits distinct infiltration patterns and hydrostratigraphic layering. A ground water flow model (MODFLOW) and a parameter estimation code (UCODE) were used to evaluate the influence of recharge zonation and hydrostratigraphic layering on base flow distribution. Optimization after removing spatial recharge variability from the calibrated model altered base flow simulations up to 53% in watersheds smaller than 40 km2. Merging six hydrostratigraphic units into one unit with average properties increased base flow residuals up to 83% in basins smaller than 50 km2. Base flow residuals changed <5% in watersheds larger than 40 and 50 km2 when recharge and hydrostratigraphy were simplified, respectively; thus, the critical basin size for the example area is ???40 to 50 km2. Once identified for an area, a critical basin size could be used to guide the scale of future investigations. By ensuring that parameter discretization needed to capture base flow distribution is commensurate with the scope of the investigation, uncertainty caused by overextending uniform parameterization or by estimating extra parameter values is reduced. ?? 2006 National Ground Water Association.

  20. Evaluation of Recharge Potential at Crater U5a (WISHBONE)

    SciTech Connect

    Richard H. French; Samuel L. Hokett

    1998-11-01

    Radionuclides are present both below and above the water table at the Nevada Test Site (NTS), as the result of underground nuclear testing. Mobilization and transport of radionuclides from the vadose zone is a complex process that is influenced by the solubility and sorption characteristics of the individual radionuclides, as well as the soil water flux. On the NTS, subsidence craters resulting from testing underground nuclear weapons are numerous, and many intercept surface water flows. Because craters collect surface water above the sub-surface point of device detonation, these craters may provide a mechanism for surface water to recharge the groundwater aquifer system underlying the NTS. Given this situation, there is a potential for the captured water to introduce contaminants into the groundwater system. Crater U5a (WISHBONE), located in Frenchman Flat, was selected for study because of its potentially large drainage area, and significant erosional features, which suggested that it has captured more runoff than other craters in the Frenchman Flat area. Recharge conditions were studied in subsidence crater U5a by first drilling boreholes and analyzing the collected soil cores to determine the soil properties and moisture conditions. This information, coupled with a 32-year precipitation record, was used to conduct surface and vaodse zone modeling. Surface water modeling predicted that approximately 13 ponding events had occurred during the life of the crater. Vadose zone modeling indicated that since the crater's formation approximately 5,900 m3 of water were captured by the crater. Of this total, approximately 5,200 m3 of potential recahrge may have occurred, and the best estimates of annual average potential recharge rates lie between 36 and 188 cm of water per year. The term potential is used here to indicate that the water is not technically recharged because it has not yet reached the water table.

  1. Recharge in Volcanic Systems: Evidence from Isotope Profiles of Phenocrysts

    PubMed

    Davidson; Tepley

    1997-02-01

    Strontium isotope ratios measured from core to rim across plagioclase feldspar crystals can be used to monitor changes in the isotope composition of the magma from which they grew. In samples from three magma systems from convergent margin volcanoes, sudden changes in major element composition, petrographic features, and strontium isotope composition were found to correspond to discrete magmatic events, most likely repeated recharge of more mafic magma with lower ratios of strontium-87 to strontium-86 into a crustally contaminated magma. PMID:9012348

  2. Spatial and temporal infiltration dynamics during managed aquifer recharge.

    PubMed

    Racz, Andrew J; Fisher, Andrew T; Schmidt, Calla M; Lockwood, Brian S; Los Huertos, Marc

    2012-01-01

    Natural groundwater recharge is inherently difficult to quantify and predict, largely because it comprises a series of processes that are spatially distributed and temporally variable. Infiltration ponds used for managed aquifer recharge (MAR) provide an opportunity to quantify recharge processes across multiple scales under semi-controlled conditions. We instrumented a 3-ha MAR infiltration pond to measure and compare infiltration patterns determined using whole-pond and point-specific methods. Whole-pond infiltration was determined by closing a transient water budget (accounting for inputs, outputs, and changes in storage), whereas point-specific infiltration rates were determined using heat as a tracer and time series analysis at eight locations in the base of the pond. Whole-pond infiltration, normalized for wetted area, rose rapidly to more than 1.0 m/d at the start of MAR operations (increasing as pond stage rose), was sustained at high rates for the next 40 d, and then decreased to less than 0.1 m/d by the end of the recharge season. Point-specific infiltration rates indicated high spatial and temporal variability, with the mean of measured values generally being lower than rates indicated by whole-pond calculations. Colocated measurements of head gradients within saturated soils below the pond were combined with infiltration rates to calculate soil hydraulic conductivity. Observations indicate a brief period of increasing saturated hydraulic conductivity, followed by a decrease of one to two orders of magnitude during the next 50 to 75 d. Locations indicating the most rapid infiltration shifted laterally during MAR operation, and we suggest that infiltration may function as a "variable source area" processes, conceptually similar to catchment runoff.

  3. Assimilating ambiguous observations to jointly estimate groundwater recharge and conductivity

    NASA Astrophysics Data System (ADS)

    Erdal, Daniel; Cirpka, Olaf A.

    2016-04-01

    In coupled modelling of catchments, the groundwater compartment can be an important water storage as well as having influence on both rivers and evapotranspirational fluxes. It is therefore important to parameterize the groundwater model as correctly as possible. Primarily important to regional groundwater flow is the spatially variable hydraulic conductivity. However, also the groundwater recharge, in a coupled system coming from the unsaturated zone but in a stand-alone groundwater model a boundary condition, is also of high importance. As with all subsurface systems, groundwater properties are difficult to observe in reality and their estimation is an ongoing topic in groundwater research and practice. Commonly, we have to rely on time series of groundwater head observations as base for any parameter estimation. Heads, however, have the drawback that they can be ambiguous and may not uniquely define the inverse problem, especially if both recharge and conductivity are seen as unknown. In the presented work we use a 2D virtual groundwater test case to investigate how the prior knowledge of recharge and conductivity influence their respective and joint estimation as spatially variable fields using head data. Using the Ensemble Kalman filter, it is shown that the joint estimation is possible if the prior knowledge is good enough. If the prior is erroneous the a-priori sampled fields cannot be corrected by the data. However, it is also shown that if the prior knowledge is directly wrong the estimated recharge field can resemble the true conductivity field, resulting in a model that meets the observations but has very poor predictive power. The study exemplifies the importance of prior knowledge in the joint estimation of parameters from ambiguous measurements.

  4. The MOLICEL(R) rechargeable lithium system: Multicell battery aspects

    NASA Technical Reports Server (NTRS)

    Fouchard, D.; Taylor, J. B.

    1987-01-01

    MOLICEL rechargeable lithium cells were cycled in batteries using series, parallel, and series/parallel connections. The individual cell voltages and branch currents were measured to understand the cell interactions. The observations were interpreted in terms of the inherent characteristics of the Li/MoS2 system and in terms of a singular cell failure mode. The results confirm that correctly configured multicell batteries using MOLICELs have performance characteristics comparable to those of single cells.

  5. Estimating recharge at Yucca Mountain, Nevada, USA: Comparison of methods

    USGS Publications Warehouse

    Flint, A.L.; Flint, L.E.; Kwicklis, E.M.; Fabryka-Martin, J. T.; Bodvarsson, G.S.

    2002-01-01

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for arid environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 mm/year near Yucca Crest. Site-scale recharge estimates range from less than 1 to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface.

  6. Estimating recharge at Yucca Mountain, Nevada, USA: comparison of methods

    NASA Astrophysics Data System (ADS)

    Flint, Alan L.; Flint, Lorraine E.; Kwicklis, Edward M.; Fabryka-Martin, June T.; Bodvarsson, Gudmundur S.

    2002-02-01

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for arid environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 mm/year near Yucca Crest. Site-scale recharge estimates range from less than 1 to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface.

  7. Changes in vegetation diversity caused by artificial recharge

    USGS Publications Warehouse

    Van Hylckama, T. E. A.

    1979-01-01

    Efforst to increase the rate of artificial recharge through basins often necessitates scrapping and ditching before and during operations. Such operations can result in more or less drastic changes in vegetation (depending on what was there before), characterized by diminisched numbers of species and lowered diversity. Two examples, one from Texas and one from the Netherlands are presented showing how similar treatments cause similar changes in two completely difference plant communities. ?? 1979 Dr. W. Junk b.v. - Publishers.

  8. Estimating recharge at yucca mountain, nevada, usa: comparison of methods

    SciTech Connect

    Flint, A. L.; Flint, L. E.; Kwicklis, E. M.; Fabryka-Martin, J. T.; Bodvarsson, G. S.

    2001-11-01

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for and environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 nun/year near Yucca Crest. Site-scale recharge estimates range from less than I to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface. [References: 57

  9. Estimating recharge at Yucca Mountain, Nevada: A case study

    SciTech Connect

    Flint, A.; Flint, L.; Kwicklis, E.; Fabryka-Martin, J.; Bodvarsson, G.S.

    2001-05-13

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for arid environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 mm/year near Yucca Crest. Site-scale recharge estimates range from less than 1 to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface.

  10. Estimation of groundwater recharge parameters by time series analysis.

    USGS Publications Warehouse

    Naff, R.L.; Gutjahr, A.L.

    1983-01-01

    A model is proposed that relates water level fluctuations in a Dupuit aquifer to effective precipitation at the top of the unsaturated zone. Effective precipitation, defined herein as that portion of precipitation which becomes recharge, is related to precipitation measured in a nearby gage by a two-parameter function. A second-order stationary assumption is used to connect the spectra of effective precipitation and water level fluctuations.-from Authors

  11. Managed aquifer recharge: rediscovering nature as a leading edge technology.

    PubMed

    Dillon, P; Toze, S; Page, D; Vanderzalm, J; Bekele, E; Sidhu, J; Rinck-Pfeiffer, S

    2010-01-01

    Use of Managed Aquifer Recharge (MAR) has rapidly increased in Australia, USA, and Europe in recent years as an efficient means of recycling stormwater or treated sewage effluent for non-potable and indirect potable reuse in urban and rural areas. Yet aquifers have been relied on knowingly for water storage and unwittingly for water treatment for millennia. Hence if 'leading edge' is defined as 'the foremost part of a trend; a vanguard', it would be misleading to claim managed aquifer recharge as a leading edge technology. However it has taken a significant investment in scientific research in recent years to demonstrate the effectiveness of aquifers as sustainable treatment systems to enable managed aquifer recharge to be recognised along side engineered treatment systems in water recycling. It is a 'cross-over' technology that is applicable to water and wastewater treatment and makes use of passive low energy processes to spectacularly reduce the energy requirements for water supply. It is robust within limits, has low cost, is suitable from village to city scale supplies, and offers as yet almost untapped opportunities for producing safe drinking water supplies where they do not yet exist. It will have an increasingly valued role in securing water supplies to sustain cities affected by climate change and population growth. However it is not a universal panacea and relies on the presence of suitable aquifers and sources of water together with effective governance to ensure human health and environment protection and water resources planning and management. This paper describes managed aquifer recharge, illustrates its use in Australia, outlining economics, guidelines and policies, and presents some of the knowledge about aquifer treatment processes that are revealing the latent value of aquifers as urban water infrastructure and provide a driver to improving our understanding of urban hydrogeology. PMID:21076220

  12. Borehole logging at the COSC-1 drill hole: a new dataset of in-situ geophysical properties through the lower Seve Nappe Complex

    NASA Astrophysics Data System (ADS)

    Berthet, Théo; Alm, Per-Gunnar; Wenning, Quinn; Almqvist, Bjarne; Kück, Jochem; Hedin, Peter

    2015-04-01

    The Collisional Orogeny in the Scandinavian Caledonides (COSC) drilling project supported by the International Continental Drilling Program was designed to study mountain building processes in a deeply eroded Paleozoic orogen. The first half of this project, COSC-1, targeted the lower part of the high grade Seve Nappe Complex and its basal thrust zone near Åre in the Jämtland county, Sweden. From May to August 2014, the COSC drilling crew drilled to a depth of 2496 m from the surface with an almost fully recovered core sample. During this drilling period, four borehole-logging runs have been conducted by Lund University with a low impact on drilling schedule and two supplementary ones once the drilling was completed. Three-Arm Caliper, Electrical Logging, Sidewall Density, Flowing Fluid Electric Conductivity, High Resolution Acoustic Televiewer and Full Waveform Sonic sondes have been used to investigate in-situ physical properties of the borehole. In addition, the ICDP operational support group has conducted two continuous borehole-logging runs from the surface to the bottom of the COSC-1 borehole in September and October. Due to technical problems, some of the planned logging have not been completed, however natural gamma, rock resistivity, magnetic susceptibility, K/Th/U concentration, temperature and fluid conductivity have been measured all along the borehole. We used the continuous natural gamma log from the ICDP logging group as the depth reference to depth-match and stack the composite borehole logging done during the drilling. These borehole logging operations result in reliable continuous data of resistivity, density, velocity, magnetic susceptibility, K/Th/U concentration, temperature, fluid conductivity, pressure, diameter as well as an image (amplitude and travel time of reflected ultrasounds) of the borehole till its bottom. Only the density, velocity and image datasets stop at 1600 m depth due to instrumentation limits. Preliminary conclusions from

  13. Geophysical interpretation of mantle magmatism in the Seiland province and adjacent Barents Sea: Implications for tectonic emplacement of the Kalak Nappe Complex

    NASA Astrophysics Data System (ADS)

    Pastore, Z.; McEnroe, S. A.; Fichler, C.

    2015-12-01

    The Seiland Igneous Province (SIP) has an exposed area of more than 5500 km2 and is the largest complex of mafic and ultramafic intrusions in northern Fennoscandia. The SIP had a massive plumbing system with deep-seated magmatic conduits that generated more than 25000 km3of igneous melts from the mantle through the continental lithosphere to the surface, at ca 560-570 Ma. The SIP is located within the Kalak Nappe Complex, a part of the Middle Allochthon of the North Norwegian Caledonides. The tectonic development, and movement from its original emplacement onto the Baltica craton is a matter of current debate. The SIP exhibits one of the most pronounced positive Bouguer gravity anomalies in northern Fennoscandia (approximately 100 mGal above background) and a clear magnetic signature. We have identified more than 10 distinct magnetic anomalies related to the Seiland Igneous Province. Here, a 3D gravity and magnetic model of the SIP integrating petrophysical data with gravity and aeromagnetic data is presented. The selected densities for the intrusive range from 2800 to 3400 kg m3, with an average density contrast to the host complex of approximately 400 kg m3. Magnetic susceptibility values, ranging from 0.004 SI to 0.2 SI, show a good correlation with the mapped ultramafic intrusions with few exceptions on the Øksfjord peninsula. A multi-profile based 3D model (IGMAS+) shows the deeper structure of the SIP. Our model suggests an irregular shape with its lower boundary varying in depth from North to South from less than 3 km to 10 Km. Two deep roots have been identified located below Seiland and Sørøya islands, the first root slightly dipping southward with two branches in the upper part. The second root is approximately vertical and T- shaped. This model contributes to the understanding of the tectonic, magmatic and the paleogeographic evolution of the SIP and adds new insights to the study of the rich hydrocarbon basins of the Southern Barents Sea.

  14. Movement of water infiltrated from a recharge basin to wells.

    PubMed

    O'Leary, David R; Izbicki, John A; Moran, Jean E; Meeth, Tanya; Nakagawa, Brandon; Metzger, Loren; Bonds, Chris; Singleton, Michael J

    2012-01-01

    Local surface water and stormflow were infiltrated intermittently from a 40-ha basin between September 2003 and September 2007 to determine the feasibility of recharging alluvial aquifers pumped for public supply, near Stockton, California. Infiltration of water produced a pressure response that propagated through unconsolidated alluvial-fan deposits to 125 m below land surface (bls) in 5 d and through deeper, more consolidated alluvial deposits to 194 m bls in 25 d, resulting in increased water levels in nearby monitoring wells. The top of the saturated zone near the basin fluctuates seasonally from depths of about 15 to 20 m. Since the start of recharge, water infiltrated from the basin has reached depths as great as 165 m bls. On the basis of sulfur hexafluoride tracer test data, basin water moved downward through the saturated alluvial deposits until reaching more permeable zones about 110 m bls. Once reaching these permeable zones, water moved rapidly to nearby pumping wells at rates as high as 13 m/d. Flow to wells through highly permeable material was confirmed on the basis of flowmeter logging, and simulated numerically using a two-dimensional radial groundwater flow model. Arsenic concentrations increased slightly as a result of recharge from 2 to 6 µg/L immediately below the basin. Although few water-quality issues were identified during sample collection, high groundwater velocities and short travel times to nearby wells may have implications for groundwater management at this and at other sites in heterogeneous alluvial aquifers. PMID:21740423

  15. Rechargeable Room-Temperature Na-CO2 Batteries.

    PubMed

    Hu, Xiaofei; Sun, Jianchao; Li, Zifan; Zhao, Qing; Chen, Chengcheng; Chen, Jun

    2016-05-23

    Developing rechargeable Na-CO2 batteries is significant for energy conversion and utilization of CO2 . However, the reported batteries in pure CO2 atmosphere are non-rechargeable with limited discharge capacity of 200 mAh g(-1) . Herein, we realized the rechargeability of a Na-CO2 battery, with the proposed and demonstrated reversible reaction of 3 CO2 +4 Na↔2 Na2 CO3 +C. The battery consists of a Na anode, an ether-based electrolyte, and a designed cathode with electrolyte-treated multi-wall carbon nanotubes, and shows reversible capacity of 60000 mAh g(-1) at 1 A g(-1) (≈1000 Wh kg(-1) ) and runs for 200 cycles with controlled capacity of 2000 mAh g(-1) at charge voltage <3.7 V. The porous structure, high electro-conductivity, and good wettability of electrolyte to cathode lead to reduced electrochemical polarization of the battery and further result in high performance. Our work provides an alternative approach towards clean recycling and utilization of CO2 .

  16. Trace organic chemicals contamination in ground water recharge.

    PubMed

    Díaz-Cruz, M Silvia; Barceló, Damià

    2008-06-01

    Population growth and unpredictable climate changes will pose high demands on water resources in the future. Even at present, surface water is certainly not enough to cope with the water requirement for agricultural, industrial, recreational and drinking purposes. In this context, the usage of ground water has become essential, therefore, their quality and quantity has to be carefully managed. Regarding quantity, artificial recharge can guarantee a sustainable level of ground water, whilst the strict quality control of the waters intended for recharge will minimize contamination of both the ground water and aquifer area. However, all water resources in the planet are threatened by multiple sources of contamination coming from the extended use of chemicals worldwide. In this respect, the environmental occurrence of organic micropollutants such as pesticides, pharmaceuticals, industrial chemicals and their metabolites has experienced fast growing interest. In this paper an overview of the priority and emerging organic micropollutants in the different source waters used for artificial aquifer recharge purposes and in the recovered water is presented. Besides, some considerations regarding fate and removal of such compounds are also addressed.

  17. Issue and challenges facing rechargeable thin film lithium batteries

    SciTech Connect

    Patil, Arun; Patil, Vaishali; Shin, Dong Wook; Choi, Ji-Won; Paik, Dong-Soo; Yoon, Seok-Jin

    2008-08-04

    New materials hold the key to fundamental advances in energy conversion and storage, both of which are vital in order to meet the challenge of global warming and the finite nature of fossil fuels. Nanomaterials in particular offer unique properties or combinations of properties as electrodes and electrolytes in a range of energy devices. Technological improvements in rechargeable solid-state batteries are being driven by an ever-increasing demand for portable electronic devices. Lithium batteries are the systems of choice, offering high energy density, flexible, lightweight design and longer lifespan than comparable battery technologies. We present a brief historical review of the development of lithium-based thin film rechargeable batteries highlight ongoing research strategies and discuss the challenges that remain regarding the discovery of nanomaterials as electrolytes and electrodes for lithium batteries also this article describes the possible evolution of lithium technology and evaluates the expected improvements, arising from new materials to cell technology. New active materials under investigation and electrode process improvements may allow an ultimate final energy density of more than 500 Wh/L and 200 Wh/kg, in the next 5-6 years, while maintaining sufficient power densities. A new rechargeable battery technology cannot be foreseen today that surpasses this. This report will provide key performance results for thin film batteries and highlight recent advances in their development.

  18. Wastewater reclamation and recharge: A water management strategy for Albuquerque

    SciTech Connect

    Gorder, P.J.; Brunswick, R.J.; Bockemeier, S.W.

    1995-12-31

    Approximately 61,000 acre-feet of the pumped water is annually discharged to the Rio Grande as treated wastewater. Albuquerque`s Southside Water Reclamation Plant (SWRP) is the primary wastewater treatment facility for most of the Albuquerque area. Its current design capacity is 76 million gallons per day (mgd), which is expected to be adequate until about 2004. A master plan currently is being prepared (discussed here in Wastewater Master Planning and the Zero Discharge Concept section) to provide guidelines for future expansions of the plant and wastewater infrastructure. Construction documents presently are being prepared to add ammonia and nitrogen removal capability to the plant, as required by its new discharge permit. The paper discusses water management strategies, indirect potable reuse for Albuquerque, water quality considerations for indirect potable reuse, treatment for potable reuse, geohydrological aspects of a recharge program, layout and estimated costs for a conceptual reclamation and recharge system, and work to be accomplished under phase 2 of the reclamation and recharge program.

  19. Identification of priority organic compounds in groundwater recharge of China.

    PubMed

    Li, Zhen; Li, Miao; Liu, Xiang; Ma, Yeping; Wu, Miaomiao

    2014-09-15

    Groundwater recharge using reclaimed water is considered a promising method to alleviate groundwater depletion, especially in arid areas. Traditional water treatment systems are inefficient to remove all the types of contaminants that would pose risks to groundwater, so it is crucial to establish a priority list of organic compounds (OCs) that deserve the preferential treatment. In this study, a comprehensive ranking system was developed to determine the list and then applied to China. 151 OCs, for which occurrence data in the wastewater treatment plants were available, were selected as candidate OCs. Based on their occurrence, exposure potential and ecological effects, two different rankings of OCs were established respectively for groundwater recharge by surface infiltration and direct aquifer injection. Thirty-four OCs were regarded as having no risks while the remaining 117 OCs were divided into three groups: high, moderate and low priority OCs. Regardless of the recharge way, nonylphenol, erythromycin and ibuprofen were the highest priority OCs; their removal should be prioritized. Also the database should be updated as detecting technology is developed.

  20. Movement of water infiltrated from a recharge basin to wells

    USGS Publications Warehouse

    O'Leary, David R.; Izbicki, John A.; Moran, Jean E.; Meeth, Tanya; Nakagawa, Brandon; Metzger, Loren; Bonds, Chris; Singleton, Michael J.

    2012-01-01

    Local surface water and stormflow were infiltrated intermittently from a 40-ha basin between September 2003 and September 2007 to determine the feasibility of recharging alluvial aquifers pumped for public supply, near Stockton, California. Infiltration of water produced a pressure response that propagated through unconsolidated alluvial-fan deposits to 125 m below land surface (bls) in 5 d and through deeper, more consolidated alluvial deposits to 194 m bls in 25 d, resulting in increased water levels in nearby monitoring wells. The top of the saturated zone near the basin fluctuates seasonally from depths of about 15 to 20 m. Since the start of recharge, water infiltrated from the basin has reached depths as great as 165 m bls. On the basis of sulfur hexafluoride tracer test data, basin water moved downward through the saturated alluvial deposits until reaching more permeable zones about 110 m bls. Once reaching these permeable zones, water moved rapidly to nearby pumping wells at rates as high as 13 m/d. Flow to wells through highly permeable material was confirmed on the basis of flowmeter logging, and simulated numerically using a two-dimensional radial groundwater flow model. Arsenic concentrations increased slightly as a result of recharge from 2 to 6 μg/L immediately below the basin. Although few water-quality issues were identified during sample collection, high groundwater velocities and short travel times to nearby wells may have implications for groundwater management at this and at other sites in heterogeneous alluvial aquifers.

  1. Multiple batch recharging for industrial CZ silicon growth

    NASA Astrophysics Data System (ADS)

    Fickett, B.; Mihalik, G.

    2001-05-01

    The Czochralski (CZ) crystal growth process used in the Siemens Solar Industries’ (SSI) Vancouver, WA facility was non-continuous. Each furnace run's production was limited by the size of the starting charge. Once the charge was depleted, the furnace was shut down, cooled, and set back up for the next run. A recharge system was developed which transforms standard CZ growth into a semi-continuous process. Now when the charge is depleted, the crucible can be refilled in situ as the grown ingot is being removed from the furnace. SSI has demonstrated up to 14 recharge cycles in a single run. The resulting benefits included: significant cost reduction, increased yield, increased throughput, reduced energy consumption, improved process capability, reduced material handling requirements, and reduced labor. The recharge system also enables the use of granular silicon, which requires less than 30% of the energy required when manufacturing silicon-starting materials. This significantly reduces the energy “pay-back” time associated with SSI's finished product, photovoltaic panels.

  2. Movement of water infiltrated from a recharge basin to wells.

    PubMed

    O'Leary, David R; Izbicki, John A; Moran, Jean E; Meeth, Tanya; Nakagawa, Brandon; Metzger, Loren; Bonds, Chris; Singleton, Michael J

    2012-01-01

    Local surface water and stormflow were infiltrated intermittently from a 40-ha basin between September 2003 and September 2007 to determine the feasibility of recharging alluvial aquifers pumped for public supply, near Stockton, California. Infiltration of water produced a pressure response that propagated through unconsolidated alluvial-fan deposits to 125 m below land surface (bls) in 5 d and through deeper, more consolidated alluvial deposits to 194 m bls in 25 d, resulting in increased water levels in nearby monitoring wells. The top of the saturated zone near the basin fluctuates seasonally from depths of about 15 to 20 m. Since the start of recharge, water infiltrated from the basin has reached depths as great as 165 m bls. On the basis of sulfur hexafluoride tracer test data, basin water moved downward through the saturated alluvial deposits until reaching more permeable zones about 110 m bls. Once reaching these permeable zones, water moved rapidly to nearby pumping wells at rates as high as 13 m/d. Flow to wells through highly permeable material was confirmed on the basis of flowmeter logging, and simulated numerically using a two-dimensional radial groundwater flow model. Arsenic concentrations increased slightly as a result of recharge from 2 to 6 µg/L immediately below the basin. Although few water-quality issues were identified during sample collection, high groundwater velocities and short travel times to nearby wells may have implications for groundwater management at this and at other sites in heterogeneous alluvial aquifers.

  3. Rechargeable Room-Temperature Na-CO2 Batteries.

    PubMed

    Hu, Xiaofei; Sun, Jianchao; Li, Zifan; Zhao, Qing; Chen, Chengcheng; Chen, Jun

    2016-05-23

    Developing rechargeable Na-CO2 batteries is significant for energy conversion and utilization of CO2 . However, the reported batteries in pure CO2 atmosphere are non-rechargeable with limited discharge capacity of 200 mAh g(-1) . Herein, we realized the rechargeability of a Na-CO2 battery, with the proposed and demonstrated reversible reaction of 3 CO2 +4 Na↔2 Na2 CO3 +C. The battery consists of a Na anode, an ether-based electrolyte, and a designed cathode with electrolyte-treated multi-wall carbon nanotubes, and shows reversible capacity of 60000 mAh g(-1) at 1 A g(-1) (≈1000 Wh kg(-1) ) and runs for 200 cycles with controlled capacity of 2000 mAh g(-1) at charge voltage <3.7 V. The porous structure, high electro-conductivity, and good wettability of electrolyte to cathode lead to reduced electrochemical polarization of the battery and further result in high performance. Our work provides an alternative approach towards clean recycling and utilization of CO2 . PMID:27089434

  4. A new analytical method for groundwater recharge and discharge estimation

    NASA Astrophysics Data System (ADS)

    Liang, Xiuyu; Zhang, You-Kuan

    2012-07-01

    SummaryA new analytical method was proposed for groundwater recharge and discharge estimation in an unconfined aquifer. The method is based on an analytical solution to the Boussinesq equation linearized in terms of h2, where h is the water table elevation, with a time-dependent source term. The solution derived was validated with numerical simulation and was shown to be a better approximation than an existing solution to the Boussinesq equation linearized in terms of h. By calibrating against the observed water levels in a monitoring well during a period of 100 days, we shown that the method proposed in this study can be used to estimate daily recharge (R) and evapotranspiration (ET) as well as the lateral drainage. It was shown that the total R was reasonably estimated with a water-table fluctuation (WTF) method if the water table measurements away from a fixed-head boundary were used, but the total ET was overestimated and the total net recharge was underestimated because of the lack of consideration of lateral drainage and aquifer storage in the WTF method.

  5. Investigation of recharge dynamics and flow paths in a fractured crystalline aquifer in semi-arid India using borehole logs: implications for managed aquifer recharge

    NASA Astrophysics Data System (ADS)

    Alazard, M.; Boisson, A.; Maréchal, J.-C.; Perrin, J.; Dewandel, B.; Schwarz, T.; Pettenati, M.; Picot-Colbeaux, G.; Kloppman, W.; Ahmed, S.

    2016-02-01

    The recharge flow paths in a typical weathered hard-rock aquifer in a semi-arid area of southern India were investigated in relation to structures associated with a managed aquifer recharge (MAR) scheme. Despite the large number of MAR structures, the mechanisms of recharge in their vicinity are still unclear. The study uses a percolation tank as a tool to identify the input signal of the recharge and uses multiple measurements (piezometric time series, electrical conductivity profiles in boreholes) compared against heat-pulse flowmeter measurements and geochemical data (major ions and stable isotopes) to examine recharge flow paths. The recharge process is a combination of diffuse piston flow and preferential flow paths. Direct vertical percolation appears to be very limited, in contradiction to the conceptual model generally admitted where vertical flow through saprolite is considered as the main recharge process. The horizontal component of the flow leads to a strong geochemical stratification of the water column. The complex recharge pattern, presented in a conceptual model, leads to varied impacts on groundwater quality and availability in both time and space, inducing strong implications for water management, water quality evolution, MAR monitoring and longer-term socio-economic costs.

  6. Ground-Water Recharge from Small Intermittent Streams in the Western Mojave Desert, California

    USGS Publications Warehouse

    Izbicki, John A.; Johnson, Russell U.; Kulongoski, Justin T.; Predmore, Steven

    2007-01-01

    Population growth has impacted ground-water resources in the western Mojave Desert, where declining water levels suggest that recharge rates have not kept pace with withdrawals. Recharge from the Mojave River, the largest hydrographic feature in the study area, is relatively well characterized. In contrast, recharge from numerous smaller streams that convey runoff from the bounding mountains is poorly characterized. The current study examined four representative streams to assess recharge from these intermittent sources. Hydraulic, thermal, geomorphic, chemical, and isotopic data were used to study recharge processes, from streamflow generation and infiltration to percolation through the unsaturated zone. Ground-water movement away from recharge areas was also assessed. Infiltration in amounts sufficient to have a measurable effect on subsurface temperature profiles did not occur in every year in instrumented study reaches. In addition to streamflow availability, results showed the importance of sediment texture in controlling infiltration and eventual recharge. Infiltration amounts of about 0.7 meters per year were an approximate threshold for the occurrence of ground-water recharge. Estimated travel times through the thick unsaturated zones underlying channels reached several hundred years. Recharging fluxes were influenced by stratigraphic complexity and depositional dynamics. Because of channel meandering, not all water that penetrates beneath the root zone can be assumed to become recharge on active alluvial fans. Away from study washes, elevated chloride concentrations and highly negative water potentials beneath the root zone indicated negligible recharge from direct infiltration of precipitation under current climatic conditions. In upstream portions of washes, generally low subsurface chloride concentrations and near-zero water potentials indicated downward movement of water toward the water table, driven primarily by gravity. Recharging conditions did not

  7. Using MODFLOW 2000 to model ET and recharge for shallow ground water problems.

    PubMed

    Doble, Rebecca C; Simmons, Craig T; Walker, Glen R

    2009-01-01

    In environments with shallow ground water elevation, small changes in the water table can cause significant variations in recharge and evapotranspiration fluxes. Particularly, where ground water is close to the soil surface, both recharge and evapotranspiration are regulated by a thin unsaturated zone and, for accuracy, must be represented using nonconstant and often nonlinear relationships. The most commonly used ground water flow model today, MODFLOW, was originally designed with a modular structure with independent packages representing recharge and evaporation processes. Systems with shallow ground water, however, may be better represented using either a recharge function that varies with ground water depth or a continuous recharge and evapotranspiration function that is dependent on depth to water table. In situations where the boundaries between recharging and nonrecharging cells change with time, such as near a seepage zone, a continuous ground water flux relationship allows recharge rates to change with depth rather than having to calculate them at each stress period. This research article describes the modification of the MODFLOW 2000 recharge and segmented evapotranspiration packages into a continuous recharge-discharge function that allows ground water flux to be represented as a continuous process, dependent on head. The modifications were then used to model long-term recharge and evapotranspiration processes on a saline, semiarid floodplain in order to understand spatial patterns of salinization, and an overview of this process is given. PMID:18624693

  8. Using MODFLOW 2000 to model ET and recharge for shallow ground water problems.

    PubMed

    Doble, Rebecca C; Simmons, Craig T; Walker, Glen R

    2009-01-01

    In environments with shallow ground water elevation, small changes in the water table can cause significant variations in recharge and evapotranspiration fluxes. Particularly, where ground water is close to the soil surface, both recharge and evapotranspiration are regulated by a thin unsaturated zone and, for accuracy, must be represented using nonconstant and often nonlinear relationships. The most commonly used ground water flow model today, MODFLOW, was originally designed with a modular structure with independent packages representing recharge and evaporation processes. Systems with shallow ground water, however, may be better represented using either a recharge function that varies with ground water depth or a continuous recharge and evapotranspiration function that is dependent on depth to water table. In situations where the boundaries between recharging and nonrecharging cells change with time, such as near a seepage zone, a continuous ground water flux relationship allows recharge rates to change with depth rather than having to calculate them at each stress period. This research article describes the modification of the MODFLOW 2000 recharge and segmented evapotranspiration packages into a continuous recharge-discharge function that allows ground water flux to be represented as a continuous process, dependent on head. The modifications were then used to model long-term recharge and evapotranspiration processes on a saline, semiarid floodplain in order to understand spatial patterns of salinization, and an overview of this process is given.

  9. Overview of Ground-Water Recharge Study Sites

    USGS Publications Warehouse

    Constantz, Jim; Adams, Kelsey S.; Stonestrom, David A.

    2007-01-01

    Multiyear studies were done to examine meteorologic and hydrogeologic controls on ephemeral streamflow and focused ground-water recharge at eight sites across the arid and semiarid southwestern United States. Campaigns of intensive data collection were conducted in the Great Basin, Mojave Desert, Sonoran Desert, Rio Grande Rift, and Colorado Plateau physiographic areas. During the study period (1997 to 2002), the southwestern region went from wetter than normal conditions associated with a strong El Ni?o climatic pattern (1997?1998) to drier than normal conditions associated with a La Ni?a climatic pattern marked by unprecedented warmth in the western tropical Pacific and Indian Oceans (1998?2002). The strong El Ni?o conditions roughly doubled precipitation at the Great Basin, Mojave Desert, and Colorado Plateau study sites. Precipitation at all sites trended generally lower, producing moderate- to severe-drought conditions by the end of the study. Streamflow in regional rivers indicated diminishing ground-water recharge conditions, with annual-flow volumes declining to 10?46 percent of their respective long-term averages by 2002. Local streamflows showed higher variability, reflecting smaller scales of integration (in time and space) of the study-site watersheds. By the end of the study, extended periods (9?15 months) of zero or negligible flow were observed at half the sites. Summer monsoonal rains generated the majority of streamflow and associated recharge in the Sonoran Desert sites and the more southerly Rio Grande Rift site, whereas winter storms and spring snowmelt dominated the northern and westernmost sites. Proximity to moisture sources (primarily the Pacific Ocean and Gulf of California) and meteorologic fluctuations, in concert with orography, largely control the generation of focused ground-water recharge from ephemeral streamflow, although other factors (geology, soil, and vegetation) also are important. Watershed area correlated weakly with focused

  10. Médecine des voyages

    PubMed Central

    Aw, Brian; Boraston, Suni; Botten, David; Cherniwchan, Darin; Fazal, Hyder; Kelton, Timothy; Libman, Michael; Saldanha, Colin; Scappatura, Philip; Stowe, Brian

    2014-01-01

    Résumé Objectif Définir la pratique de la médecine des voyages, présenter les éléments fondamentaux d’une consultation complète préalable aux voyages à des voyageurs internationaux et aider à identifier les patients qu’il vaudrait mieux envoyer en consultation auprès de professionnels de la médecine des voyages. Sources des données Les lignes directrices et les recommandations sur la médecine des voyages et les maladies liées aux voyages publiées par les autorités sanitaires nationales et internationales ont fait l’objet d’un examen. Une recension des ouvrages connexes dans MEDLINE et EMBASE a aussi été effectuée. Message principal La médecine des voyages est une spécialité très dynamique qui se concentre sur les soins préventifs avant un voyage. Une évaluation exhaustive du risque pour chaque voyageur est essentielle pour mesurer avec exactitude les risques particuliers au voyageur, à son itinéraire et à sa destination et pour offrir des conseils sur les interventions les plus appropriées en gestion du risque afin de promouvoir la santé et prévenir les problèmes médicaux indésirables durant le voyage. Des vaccins peuvent aussi être nécessaires et doivent être personnalisés en fonction des antécédents d’immunisation du voyageur, de son itinéraire et du temps qu’il reste avant son départ. Conclusion La santé et la sécurité d’un voyageur dépendent du degré d’expertise du médecin qui offre le counseling préalable à son voyage et les vaccins, au besoin. On recommande à ceux qui donnent des conseils aux voyageurs d’être conscients de l’ampleur de cette responsabilité et de demander si possible une consultation auprès de professionnels de la médecine des voyages pour tous les voyageurs à risque élevé.

  11. Implications of projected climate change for groundwater recharge in the western United States

    NASA Astrophysics Data System (ADS)

    Meixner, Thomas; Manning, Andrew H.; Stonestrom, David A.; Allen, Diana M.; Ajami, Hoori; Blasch, Kyle W.; Brookfield, Andrea E.; Castro, Christopher L.; Clark, Jordan F.; Gochis, David J.; Flint, Alan L.; Neff, Kirstin L.; Niraula, Rewati; Rodell, Matthew; Scanlon, Bridget R.; Singha, Kamini; Walvoord, Michelle A.

    2016-03-01

    Existing studies on the impacts of climate change on groundwater recharge are either global or basin/location-specific. The global studies lack the specificity to inform decision making, while the local studies do little to clarify potential changes over large regions (major river basins, states, or groups of states), a scale often important in the development of water policy. An analysis of the potential impact of climate change on groundwater recharge across the western United States (west of 100° longitude) is presented synthesizing existing studies and applying current knowledge of recharge processes and amounts. Eight representative aquifers located across the region were evaluated. For each aquifer published recharge budget components were converted into four standard recharge mechanisms: diffuse, focused, irrigation, and mountain-systems recharge. Future changes in individual recharge mechanisms and total recharge were then estimated for each aquifer. Model-based studies of projected climate-change effects on recharge were available and utilized for half of the aquifers. For the remainder, forecasted changes in temperature and precipitation were logically propagated through each recharge mechanism producing qualitative estimates of direction of changes in recharge only (not magnitude). Several key patterns emerge from the analysis. First, the available estimates indicate average declines of 10-20% in total recharge across the southern aquifers, but with a wide range of uncertainty that includes no change. Second, the northern set of aquifers will likely incur little change to slight increases in total recharge. Third, mountain system recharge is expected to decline across much of the region due to decreased snowpack, with that impact lessening with higher elevation and latitude. Factors contributing the greatest uncertainty in the estimates include: (1) limited studies quantitatively coupling climate projections to recharge estimation methods using detailed

  12. Changes in groundwater recharge under projected climate in the upper Colorado River basin

    USGS Publications Warehouse

    Tillman, Fred; Gangopadhyay, Subhrendu; Pruitt, Tom

    2016-01-01

    Understanding groundwater-budget components, particularly groundwater recharge, is important to sustainably manage both groundwater and surface water supplies in the Colorado River basin now and in the future. This study quantifies projected changes in upper Colorado River basin (UCRB) groundwater recharge from recent historical (1950–2015) through future (2016–2099) time periods, using a distributed-parameter groundwater recharge model with downscaled climate data from 97 Coupled Model Intercomparison Project Phase 5 climate projections. Simulated future groundwater recharge in the UCRB is generally expected to be greater than the historical average in most decades. Increases in groundwater recharge in the UCRB are a consequence of projected increases in precipitation, offsetting reductions in recharge that would result from projected increased temperatures.

  13. Ponds and Rice Fields: The Hydrology and Chemistry of Aquifer Recharge in Bangladesh

    NASA Astrophysics Data System (ADS)

    Neumann, R. B.; Harvey, C. F.

    2007-12-01

    The shallow aquifer in Bangladesh, which provides drinking water for millions and irrigation water for innumerable rice fields, is severely contaminated with naturally occurring arsenic. Water balance calculations show that surface ponds and irrigated rice fields are the primary sources of recharge to this contaminated aquifer. Recharge from an individual rice field is both temporally and spatially heterogeneous, whereas flow from a pond is more constant and uniform through the pond sediments. Rice field recharge is focused through bunds (the berms surrounding the field), and depends on irrigation intervals. Field flow patterns are controlled by cracks and the development of an unsaturated zone. The water chemistry of these two recharge sources is distinctly different. Compared to the rice fields, ponds contribute recharge with a higher organic carbon load and increased concentrations of solutes associated with anoxic microbial respiration. The differences in the recharge behavior and solute loads of these two sources may explain the spatial patterns of groundwater chemistry that control arsenic concentrations.

  14. Changes in groundwater recharge under projected climate in the upper Colorado River basin

    NASA Astrophysics Data System (ADS)

    Tillman, Fred D.; Gangopadhyay, Subhrendu; Pruitt, Tom

    2016-07-01

    Understanding groundwater-budget components, particularly groundwater recharge, is important to sustainably manage both groundwater and surface water supplies in the Colorado River basin now and in the future. This study quantifies projected changes in upper Colorado River basin (UCRB) groundwater recharge from recent historical (1950-2015) through future (2016-2099) time periods, using a distributed-parameter groundwater recharge model with downscaled climate data from 97 Coupled Model Intercomparison Project Phase 5 climate projections. Simulated future groundwater recharge in the UCRB is generally expected to be greater than the historical average in most decades. Increases in groundwater recharge in the UCRB are a consequence of projected increases in precipitation, offsetting reductions in recharge that would result from projected increased temperatures.

  15. Ground-water recharge through active sand dunes in northwestern Nevada

    USGS Publications Warehouse

    Berger, D.L.

    1992-01-01

    Most water-resource investigations in semiarid basins of the Great Basin in western North America conclude that ground-water recharge from direct precipitation on the valley floor is negligible. However, many of these basins contain large areas covered by unvegetated, active sand dunes that may act as conduits for ground-water recharge. The potential for this previously undocumented recharge was investigated in an area covered by sand dunes in Desert Valley, northwestern Nevada, using a deep percolation model. The model uses daily measurements of precipitation and temperature to determine energy and moisture balance, from which estimates of long-term mean annual recharge are made. For the study area, the model calculated a mean annual recharge rate of as much as 1.3 inches per year, or 17 percent of the long-term mean precipitation. Model simulations also indicate that recharge would be virtually zero if the study area were covered by vegetation rather than dunes.

  16. Soil Water Balance and Recharge Monitoring at the Hanford Site - FY09 Status Report

    SciTech Connect

    Rockhold, Mark L.; Saunders, Danielle L.; Strickland, Christopher E.; Waichler, Scott R.; Clayton, Ray E.

    2009-09-28

    Recharge provides the primary driving force for transporting contaminants from the vadose zone to underlying aquifer systems. Quantification of recharge rates is important for assessing contaminant transport and fate and for evaluating remediation alternatives. This report describes the status of soil water balance and recharge monitoring performed by Pacific Northwest National Laboratory at the Hanford Site for Fiscal Year 2009. Previously reported data for Fiscal Years 2004 - 2008 are updated with data collected in Fiscal Year 2009 and summarized.

  17. The Simulation of the Recharging Method Based on Solar Radiation for an Implantable Biosensor.

    PubMed

    Li, Yun; Song, Yong; Kong, Xianyue; Li, Maoyuan; Zhao, Yufei; Hao, Qun; Gao, Tianxin

    2016-01-01

    A method of recharging implantable biosensors based on solar radiation is proposed. Firstly, the models of the proposed method are developed. Secondly, the recharging processes based on solar radiation are simulated using Monte Carlo (MC) method and the energy distributions of sunlight within the different layers of human skin have been achieved and discussed. Finally, the simulation results are verified experimentally, which indicates that the proposed method will contribute to achieve a low-cost, convenient and safe method for recharging implantable biosensors.

  18. Shallow groundwater recharge mechanism and apparent age in the Ndop plain, northwest Cameroon

    NASA Astrophysics Data System (ADS)

    Wirmvem, Mengnjo Jude; Mimba, Mumbfu Ernestine; Kamtchueng, Brice Tchakam; Wotany, Engome Regina; Bafon, Tasin Godlove; Asaah, Asobo Nkengmatia Elvis; Fantong, Wilson Yetoh; Ayonghe, Samuel Ndonwi; Ohba, Takeshi

    2015-02-01

    Knowledge of groundwater recharge and apparent age constitutes a valuable tool for its sustainable management. Accordingly, shallow groundwater (n = 72) in the Ndop plain has been investigated using the stable isotopes of oxygen (18O) and hydrogen (2H or D) and tritium (3H) to determine the recharge process, timing and rate of recharge, and residence time. The shallow groundwater showed low variability in δ18O values (-2.7 to -4.1 ‰) and 3H content (2.4-3.1 TU). The low variability suggests a similar origin, homogenous aquifer, good water mixing and storage capacity of the groundwater reservoir. Like surface water, a cluster of groundwater along the Ndop Meteoric Water Line (NMWL) and Global Meteoric Water Line indicates meteoric origin/recharge. The rainfall recharge occurs under low relative humidity conditions and negligible evaporation effect. About 80 % of the recharge is from direct heterogeneous/diffuse local precipitation at low altitude (<1,260 m) within the Ndop plain. Approximately 20 % is from high altitude precipitation (localised recharge) or is recharged by the numerous inflowing streams and rivers from high elevations. A homogenous cluster of δ-values in groundwater (and surface water) between May and June monsoon rains on the NMWL suggests dominant recharge during these months. The recharge represents at least 16 % (>251 mm) of the annual rainfall (1,540 mm) indicating high annual recharge; high enough for development of the groundwater resource for agriculture. The 3H content (>2.4 TU) in groundwater indicates post-1952 recharged water with an estimated residence time <30 years, suggesting short subsurface circulation, and subsequently a renewable aquifer.

  19. Multi-component transport and transformation in deep confined aquifer during groundwater artificial recharge.

    PubMed

    Zhang, Wenjing; Huan, Ying; Yu, Xipeng; Liu, Dan; Zhou, Jingjing

    2015-04-01

    Taking an artificial groundwater recharge site in Shanghai, China as an example, this study employed a combination of laboratory experiment and numerical modeling to investigate the transport and transformation of major solutes, as well as the mechanism of associated water-rock interactions in groundwater during artificial groundwater recharge. The results revealed that: (1) Major ions in groundwater were mainly affected by mixing, ion exchanging (Ca(2+), Mg(2+), Na(+), K(+)), as well as dissolution of Calcite, Dolomite. Dissolution of carbonate minerals was not entirely dependent on the pattern of groundwater recharge, the reactivity of the source water itself as indicated by the sub-saturation with respect to the carbonate minerals is the primary factor. (2) Elemental dissolution of As, Cr and Fe occurred in aquifer was due to the transformation of subsurface environment from anaerobic to aerobic systems. Different to bank filtration recharge or pond recharge, the concentration of Fe near the recharge point was mainly controlled by oxidation dissolution of Siderite, which was followed by a release of As, Cr into groundwater. (3) Field modeling results revealed that the hydro chemical type of groundwater gradually changed from the initial Cl-HCO3-Na type to the Cl-HCO3-Na-Ca type during the recharge process, and its impact radius would reach roughly 800 m in one year. It indicated that the recharge pressure (approx. 0.45 Mpa) would enlarge the impact radius under deep well recharge conditions. According to different recharge modes, longer groundwater resident time will associate with minerals' fully reactions. Although the concentrations of major ions were changing during the artificial recharge process, it did not pose a negative impact on the environmental quality of groundwater. The result of trace elements indicated that controlling the environment factors (especially Eh, DO, flow rate) during the recharge was effective to reduce the potential threats to

  20. Multi-component transport and transformation in deep confined aquifer during groundwater artificial recharge.

    PubMed

    Zhang, Wenjing; Huan, Ying; Yu, Xipeng; Liu, Dan; Zhou, Jingjing

    2015-04-01

    Taking an artificial groundwater recharge site in Shanghai, China as an example, this study employed a combination of laboratory experiment and numerical modeling to investigate the transport and transformation of major solutes, as well as the mechanism of associated water-rock interactions in groundwater during artificial groundwater recharge. The results revealed that: (1) Major ions in groundwater were mainly affected by mixing, ion exchanging (Ca(2+), Mg(2+), Na(+), K(+)), as well as dissolution of Calcite, Dolomite. Dissolution of carbonate minerals was not entirely dependent on the pattern of groundwater recharge, the reactivity of the source water itself as indicated by the sub-saturation with respect to the carbonate minerals is the primary factor. (2) Elemental dissolution of As, Cr and Fe occurred in aquifer was due to the transformation of subsurface environment from anaerobic to aerobic systems. Different to bank filtration recharge or pond recharge, the concentration of Fe near the recharge point was mainly controlled by oxidation dissolution of Siderite, which was followed by a release of As, Cr into groundwater. (3) Field modeling results revealed that the hydro chemical type of groundwater gradually changed from the initial Cl-HCO3-Na type to the Cl-HCO3-Na-Ca type during the recharge process, and its impact radius would reach roughly 800 m in one year. It indicated that the recharge pressure (approx. 0.45 Mpa) would enlarge the impact radius under deep well recharge conditions. According to different recharge modes, longer groundwater resident time will associate with minerals' fully reactions. Although the concentrations of major ions were changing during the artificial recharge process, it did not pose a negative impact on the environmental quality of groundwater. The result of trace elements indicated that controlling the environment factors (especially Eh, DO, flow rate) during the recharge was effective to reduce the potential threats to

  1. Using noble gas tracers to constrain a groundwater flow model with recharge elevations: A novel approach for mountainous terrain

    USGS Publications Warehouse

    Doyle, Jessica M.; Gleeson, Tom; Manning, Andrew H.; Mayer, K. Ulrich

    2015-01-01

    Environmental tracers provide information on groundwater age, recharge conditions, and flow processes which can be helpful for evaluating groundwater sustainability and vulnerability. Dissolved noble gas data have proven particularly useful in mountainous terrain because they can be used to determine recharge elevation. However, tracer-derived recharge elevations have not been utilized as calibration targets for numerical groundwater flow models. Herein, we constrain and calibrate a regional groundwater flow model with noble-gas-derived recharge elevations for the first time. Tritium and noble gas tracer results improved the site conceptual model by identifying a previously uncertain contribution of mountain block recharge from the Coast Mountains to an alluvial coastal aquifer in humid southwestern British Columbia. The revised conceptual model was integrated into a three-dimensional numerical groundwater flow model and calibrated to hydraulic head data in addition to recharge elevations estimated from noble gas recharge temperatures. Recharge elevations proved to be imperative for constraining hydraulic conductivity, recharge location, and bedrock geometry, and thus minimizing model nonuniqueness. Results indicate that 45% of recharge to the aquifer is mountain block recharge. A similar match between measured and modeled heads was achieved in a second numerical model that excludes the mountain block (no mountain block recharge), demonstrating that hydraulic head data alone are incapable of quantifying mountain block recharge. This result has significant implications for understanding and managing source water protection in recharge areas, potential effects of climate change, the overall water budget, and ultimately ensuring groundwater sustainability.

  2. Estimated ground-water recharge from streamflow in Fortymile Wash near Yucca Mountain, Nevada

    SciTech Connect

    Savard, C.S.

    1998-10-01

    The two purposes of this report are to qualitatively document ground-water recharge from stream-flow in Fortymile Wash during the period 1969--95 from previously unpublished ground-water levels in boreholes in Fortymile Canyon during 1982--91 and 1995, and to quantitatively estimate the long-term ground-water recharge rate from streamflow in Fortymile Wash for four reaches of Fortymile Wash (Fortymile Canyon, upper Jackass Flats, lower Jackass Flats, and Amargosa Desert). The long-term groundwater recharge rate was estimated from estimates of the volume of water available for infiltration, the volume of infiltration losses from streamflow, the ground-water recharge volume from infiltration losses, and an analysis of the different periods of data availability. The volume of water available for infiltration and ground-water recharge in the four reaches was estimated from known streamflow in ephemeral Fortymile Wash, which was measured at several gaging station locations. The volume of infiltration losses from streamflow for the four reaches was estimated from a streamflow volume loss factor applied to the estimated streamflows. the ground-water recharge volume was estimated from a linear relation between infiltration loss volume and ground-water recharge volume for each of the four reaches. Ground-water recharge rates were estimated for three different periods of data availability (1969--95, 1983--95, and 1992--95) and a long-term ground-water recharge rate estimated for each of the four reaches.

  3. Modeling spatiotemporal impacts of hydroclimatic extremes on groundwater recharge at a Mediterranean karst aquifer

    NASA Astrophysics Data System (ADS)

    Hartmann, Andreas; Mudarra, Matías; Andreo, Bartolomé; Marín, Ana; Wagener, Thorsten; Lange, Jens

    2014-08-01

    Karst aquifers provide large parts of the water supply for Mediterranean countries, though climate change is expected to have a significant negative impact on water availability. Recharge is therefore a key variable that has to be known for sustainable groundwater use. In this study, we present a new approach that combines two independent methods for karst recharge estimation. The first method derives spatially distributed information of mean annual recharge patterns through GIS analysis. The second is a process-based karst model that provides spatially lumped but temporally distributed information about recharge. By combining both methods, we add a spatial reference to the lumped simulations of the process-based model. In this way, we are able to provide spatiotemporal information of recharge and subsurface flow dynamics also during varying hydroclimatic conditions. We find that there is a nonlinear relationship between precipitation and recharge rates resulting in strong decreases of recharge following even moderate decreases of precipitation. This is primarily due to almost constant actual evapotranspiration amounts despite varying hydroclimatic conditions. During the driest year in the record, almost the entire precipitation was consumed as actual evapotranspiration and only little diffuse recharge took place at the high altitudes of our study site. During wettest year, recharge constituted a much larger fraction of precipitation and occurred at the entire study site. Our new method and our findings are significant for decision makers in similar regions that want to prepare for possible changes of hydroclimatic conditions in the future.

  4. Selected techniques for monitoring water movement through unsaturated alluvium during managed aquifer recharge

    USGS Publications Warehouse

    Nawikas, Joseph M.; O'Leary, David R.; Izbicki, John A.; Burgess, Matthew K.

    2016-10-21

    Managed aquifer recharge is used to augment natural recharge to aquifers. It can be used to replenish aquifers depleted by pumping or to store water during wetter years for withdrawal during drier years. Infiltration from ponds is a commonly used, inexpensive approach for managed aquifer recharge.At some managed aquifer-recharge sites, the time when infiltrated water arrives at the water table is not always clearly shown by water-level data. As part of site characterization and operation, it can be desirable to track downward movement of infiltrated water through the unsaturated zone to identify when it arrives at the water table.

  5. Recharge processes in an alluvial aquifer riparian zone, Norman Landfill, Norman, Oklahoma, 1998-2000

    USGS Publications Warehouse

    Scholl, Martha; Christenson, Scott; Cozzarelli, Isabelle; Ferree, Dale; Jaeshke, Jeanne

    2005-01-01

    Analyses of stable isotope profiles (d2H and d18O) in the saturated zone, combined with water-table fluctuations, gave a comprehensive picture of recharge processes in an alluvial aquifer riparian zone. At the Norman Landfill U.S. Geological Survey Toxic Substances Hydrology research site in Norman, Oklahoma, recharge to the aquifer appears to drive biodegradation, contributing fresh supplies of electron acceptors for the attenuation of leachate compounds from the landfill. Quantifying recharge is a first step in studying this process in detail. Both chemical and physical methods were used to estimate recharge. Chemical methods included measuring the increase in recharge water in the saturated zone, as defined by isotopic signature, specific conductance or chloride measurements; and infiltration rate estimates using storm event isotopic signatures. Physical methods included measurement of water-table rise after individual rain events and on an approximately monthly time scale. Evapotranspiration rates were estimated using diurnal watertable fluctuations; outflux of water from the alluvial aquifer during the growing season had a large effect on net recharge at the site. Evaporation and methanogenesis gave unique isotopic signatures to different sources of water at the site, allowing the distinction of recharge using the offset of the isotopic signature from the local meteoric water line. The downward movement of water from large, isotopically depleted rain events in the saturated zone yielded recharge rate estimates (2.2 - 3.3 mm/day), and rates also were determined by observing changes in thickness of the layer of infiltrated recharge water at the top of the saturated zone (1.5 - 1.6 mm/day). Recharge measured over 2 years (1998-2000) in two locations at the site averaged 37 percent of rainfall, however, part of this water had only a short residence time in the aquifer. Isotopes showed recharge water entering the ground-water system in winter and spring, then being

  6. Groundwater recharge at five representative sites in the Hebei Plain, China.

    PubMed

    Lu, Xiaohui; Jin, Menggui; van Genuchten, Martinus Th; Wang, Bingguo

    2011-01-01

    Accurate estimates of groundwater recharge are essential for effective management of groundwater, especially when supplies are limited such as in many arid and semiarid areas. In the Hebei Plain, China, water shortage is increasingly restricting socioeconomic development, especially for agriculture, which heavily relies on groundwater. Human activities have greatly changed groundwater recharge there during the past several decades. To obtain better estimates of recharge in the plain, five representative sites were selected to investigate the effects of irrigation and water table depth on groundwater recharge. At each site, a one-dimensional unsaturated flow model (Hydrus-1D) was calibrated using field data of climate, soil moisture, and groundwater levels. A sensitivity analysis of evapotranspirative fluxes and various soil hydraulic parameters confirmed that fine-textured surface soils generally generate less recharge. Model calculations showed that recharge on average is about 175 mm/year in the piedmont plain to the west, and 133 mm/year in both the central alluvial and lacustrine plains and the coastal plain to the east. Temporal and spatial variations in the recharge processes were significant in response to rainfall and irrigation. Peak time-lags between infiltration (rainfall plus irrigation) and recharge were 18 to 35 days in the piedmont plain and 3 to 5 days in the central alluvial and lacustrine plains, but only 1 or 2 days in the coastal plain. This implies that different time-lags corresponding to different water table depths must be considered when estimating or modeling groundwater recharge.

  7. Seasonalizing mountain system recharge in semi-arid basins-climate change impacts.

    PubMed

    Ajami, Hoori; Meixner, Thomas; Dominguez, Francina; Hogan, James; Maddock, Thomas

    2012-01-01

    Climate variability and change impact groundwater resources by altering recharge rates. In semi-arid Basin and Range systems, this impact is likely to be most pronounced in mountain system recharge (MSR), a process which constitutes a significant component of recharge in these basins. Despite its importance, the physical processes that control MSR have not been fully investigated because of limited observations and the complexity of recharge processes in mountainous catchments. As a result, empirical equations, that provide a basin-wide estimate of mean annual recharge using mean annual precipitation, are often used to estimate MSR. Here North American Regional Reanalysis data are used to develop seasonal recharge estimates using ratios of seasonal (winter vs. summer) precipitation to seasonal actual or potential evapotranspiration. These seasonal recharge estimates compared favorably to seasonal MSR estimates using the fraction of winter vs. summer recharge determined from isotopic data in the Upper San Pedro River Basin, Arizona. Development of hydrologically based seasonal ratios enhanced seasonal recharge predictions and notably allows evaluation of MSR response to changes in seasonal precipitation and temperature because of climate variability and change using Global Climate Model (GCM) climate projections. Results show that prospective variability in MSR depends on GCM precipitation predictions and on higher temperature. Lower seasonal MSR rates projected for 2050-2099 are associated with decreases in summer precipitation and increases in winter temperature. Uncertainty in seasonal MSR predictions arises from the potential evapotranspiration estimation method, the GCM downscaling technique and the exclusion of snowmelt processes.

  8. Use of soil moisture probes to estimate ground water recharge at an oil spill site

    USGS Publications Warehouse

    Delin, G.N.; Herkelrath, W.N.

    2005-01-01

    Soil moisture data collected using an automated data logging system were used to estimate ground water recharge at a crude oil spill research site near Bemidji, Minnesota. Three different soil moisture probes were tested in the laboratory as well as the field conditions of limited power supply and extreme weather typical of northern Minnesota: a self-contained reflectometer probe, and two time domain reflectometry (TDR) probes, 30 and 50 cm long. Recharge was estimated using an unsaturated zone water balance method. Recharge estimates for 1999 using the laboratory calibrations were 13 to 30 percent greater than estimates based on the factory calibrations. Recharge indicated by the self-contained probes was 170 percent to 210 percent greater than the estimates for the TDR probes regardless of calibration method. Results indicate that the anomalously large recharge estimates for the self-contained probes are not the result of inaccurate measurements of volumetric moisture content, but result from the presence of crude oil, or bore-hole leakage. Of the probes tested, the 50 cm long TDR probe yielded recharge estimates that compared most favorably to estimates based on a method utilizing water table fluctuations. Recharge rates for this probe represented 24 to 27 percent of 1999 precipitation. Recharge based on the 30 cm long horizontal TDR probes was 29 to 37 percent of 1999 precipitation. By comparison, recharge based on the water table fluctuation method represented about 29 percent of precipitation. (JAWRA) (Copyright ?? 2005).

  9. A generalized estimate of ground-water-recharge rates in the Lower Peninsula of Michigan

    USGS Publications Warehouse

    Holtschlag, David J.

    1997-01-01

    Ground-water recharge rates were estimated by analysis of streamflow, precipitation, and basin-characteristics data. Streamflow data were partitioned into ground-water-discharge and surface-water-runoff components. Regression equations relate ground-water discharge to precipitation at each basin. Basin-characteristics and long-term precipitation data were used to aid in the interpolation of recharge characteristics within gaged and ungaged areas. A multiple regression equation was developed to estimate spatial variation of recharge. The generalized estimate provides a consistent method for approximating recharge rates in the Lower Peninsula of Michigan.

  10. SWB-A modified Thornthwaite-Mather Soil-Water-Balance code for estimating groundwater recharge

    USGS Publications Warehouse

    Westenbroek, S.M.; Kelson, V.A.; Dripps, W.R.; Hunt, R.J.; Bradbury, K.R.

    2010-01-01

    A Soil-Water-Balance (SWB) computer code has been developed to calculate spatial and temporal variations in groundwater recharge. The SWB model calculates recharge by use of commonly available geographic information system (GIS) data layers in combination with tabular climatological data. The code is based on a modified Thornthwaite-Mather soil-water-balance approach, with components of the soil-water balance calculated at a daily timestep. Recharge calculations are made on a rectangular grid of computational elements that may be easily imported into a regional groundwater-flow model. Recharge estimates calculated by the code may be output as daily, monthly, or annual values.

  11. A numerical analysis on the applicability of the water level fluctuation method for quantifying groundwater recharge

    NASA Astrophysics Data System (ADS)

    Koo, M.; Lee, D.

    2002-12-01

    The water table fluctuation(WTF) method is a conventional method for quantifying groundwater recharge by multiplying the specific yield to the water level rise. Based on the van Genuchten model, an analytical relationship between groundwater recharge and the water level rise is derived. The equation is used to analyze the effects of the depth to water level and the soil properties on the recharge estimate using the WTF method. The results show that the WTF method is reliable when applied to the aquifers of the fluvial sand provided the water table is below 1m depth. However, if it is applied to the silt loam having the water table depth ranging 4~10m, the recharge is overestimated by 30~80%, and the error increases drastically as the water table is getting shallower. A 2-D unconfined flow model with a time series of the recharge rate is developed. It is used for elucidating the errors of the WTF method, which is implicitly based on the tank model where the horizontal flow in the saturated zone is ignored. Simulations show that the recharge estimated by the WTF method is underestimated for the observation well near the discharge boundary. This is due to the fact that the hydraulic stress resulting from the recharge is rapidly dissipating by the horizontal flow near the discharge boundary. Simulations also reveal that the recharge is significantly underestimated with increase in the hydraulic conductivity and the recharge duration, and decrease in the specific yield.

  12. Estimation of groundwater recharge from water storage structures in a semi-arid climate of India

    NASA Astrophysics Data System (ADS)

    Sharda, V. N.; Kurothe, R. S.; Sena, D. R.; Pande, V. C.; Tiwari, S. P.

    2006-09-01

    SummaryGroundwater recharge from water storage structures under semi-arid conditions of western India has been estimated by employing water table fluctuation (WTF) and chloride mass balance (CMB) methods. Groundwater recharge was estimated as 7.3% and 9.7% of the annual rainfall by WTF method for the years 2003 and 2004, respectively while the two years average recharge was estimated as 7.5% using CMB method. A Recharge function depicting the relationship between potential recharge from storage structures and successive day averaged storage depths was better exhibited by a power function. A diagnostic relationship correlating the rainfall to the potential recharge from water storage structures has been developed to explain the characteristics of the storage structures for a given geographical location. The study has revealed that a minimum of 104.3 mm cumulative rainfall is required to generate 1 mm of recharge from the water storage structures. It was also inferred that the storage structures have limited capacity to induce maximum recharge irrespective of the amount of rainfall and maximum recharge to rainfall ratio is achieved at a lower rainfall than the average annual rainfall of the area. An empirical linear relationship was found to reasonably correlate the changes in chloride concentration with water table rise or fall in the study area.

  13. Artificial-recharge investigation near Aurora, Nebraska: 2-year progress report

    USGS Publications Warehouse

    Lichtler, William F.; Stannard, David I.; Kouma, Edwin

    1979-01-01

    This report presents the results of the first 2 years of a 4-year investigation of potential for artificial recharge and recharge methods that might be used to mitigate excessive aquifer depletion in Nebraska. A Quaternary sand-and-gravel aquifer near Aurora, Nebr., was recharged by injecting water through a well at a rate of approximately 730 gallons per minute for nearly 6 months. Total recharge was 530 acre-feet. Recharge was intermittent during the first 2 months, but was virtually continuous during the last 4 months. Buildup of the water level in the recharge well was 17 feet. The rate of buildup indicates that the well could have accepted water by gravity flow at more than 3,000 gallons per minute for at least 1 year. The cause of a continuing slow rise in water levels in the recharge well in contrast to nearly stable water levels in observation wells as close as 10 feet from the recharge well is as yet uncertain. The recharge water and the native ground water appeared to be chemically compatible. Infiltration rates from 24-foot-diameter surface impoundments ranged from 0.04 to 0.66 feet per day. The higher rates may have resulted in part from leakage down incompletely sealed holes that were drilled to install monitoring equipment. The investigation, including a report on the entire project, is scheduled for completion by 1980.

  14. Artificial recharge through a thick, heterogeneous unsaturated zone.

    PubMed

    Izbicki, John A; Flint, Alan L; Stamos, Christina L

    2008-01-01

    Thick, heterogeneous unsaturated zones away from large streams in desert areas have not previously been considered suitable for artificial recharge from ponds. To test the potential for recharge in these settings, 1.3 x 10(6) m(3) of water was infiltrated through a 0.36-ha pond along Oro Grande Wash near Victorville, California, between October 2002 and January 2006. The pond overlies a regional pumping depression 117 m below land surface and is located where thickness and permeability of unsaturated deposits allowed infiltration and saturated alluvial deposits were sufficiently permeable to allow recovery of water. Because large changes in water levels caused by nearby pumping would obscure arrival of water at the water table, downward movement of water was measured using sensors in the unsaturated zone. The downward rate of water movement was initially as high as 6 m/d and decreased with depth to 0.07 m/d; the initial time to reach the water table was 3 years. After the unsaturated zone was wetted, water reached the water table in 1 year. Soluble salts and nitrate moved readily with the infiltrated water, whereas arsenic and chromium were less mobile. Numerical simulations done using the computer program TOUGH2 duplicated the downward rate of water movement, accumulation of water on perched zones, and its arrival at the water table. Assuming 10 x 10(6) m(3) of recharge annually for 20 years, a regional ground water flow model predicted water level rises of 30 m beneath the ponds, and rises exceeding 3 m in most wells serving the nearby urban area. PMID:18194322

  15. Artificial recharge through a thick, heterogeneous unsaturated zone

    USGS Publications Warehouse

    Izbicki, J.A.; Flint, A.L.; Stamos, C.L.

    2008-01-01

    Thick, heterogeneous unsaturated zones away from large streams in desert areas have not previously been considered suitable for artificial recharge from ponds. To test the potential for recharge in these settings, 1.3 ?? 10 6 m3 of water was infiltrated through a 0.36-ha pond along Oro Grande Wash near Victorville, California, between October 2002 and January 2006. The pond overlies a regional pumping depression 117 m below land surface and is located where thickness and permeability of unsaturated deposits allowed infiltration and saturated alluvial deposits were sufficiently permeable to allow recovery of water. Because large changes in water levels caused by nearby pumping would obscure arrival of water at the water table, downward movement of water was measured using sensors in the unsaturated zone. The downward rate of water movement was initially as high as 6 m/d and decreased with depth to 0.07 m/d; the initial time to reach the water table was 3 years. After the unsaturated zone was wetted, water reached the water table in 1 year. Soluble salts and nitrate moved readily with the infiltrated water, whereas arsenic and chromium were less mobile. Numerical simulations done using the computer program TOUGH2 duplicated the downward rate of water movement, accumulation of water on perched zones, and its arrival at the water table. Assuming 10 ?? 10 6 m3 of recharge annually for 20 years, a regional ground water flow model predicted water level rises of 30 m beneath the ponds, and rises exceeding 3 m in most wells serving the nearby urban area.

  16. ~100 Ma Lu-Hf eclogite ages from Koralpe and Saualpe (Austroalpine nappes, Austria): New constraints for the kinematics of Eoalpine subduction

    NASA Astrophysics Data System (ADS)

    Miladinova, Irena; Froitzheim, Nikolaus; Nagel, Thorsten; Janák, Marian; Münker, Carsten

    2016-04-01

    The Koralpe and Saualpe complexes are part of the Austroalpine basement nappe system. They represent the largest region in the Eastern Alps exposing high-pressure metamorphic rocks from the Cretaceous Eoalpine orogenic event and also contain the type locality for eclogite. The grade of the Cretaceous metamorphism in the Eastern Alps increases to the southeast, with maximum pressures and temperatures reaching up to 3.5 GPa and 850 °C in the Pohorje Mountains (Janak et al., 2015). The estimated P-T-conditions for the eclogites from Saualpe and Koralpe are 2-2.2 GPa and 600-740 °C (Miller & Thöni 1997, Thöni et al. 2008). Here we present a new Lu-Hf isotopic study of the eclogites from the Hohl locality in the southern Koralpe, and from the Grünburgerbach and Wolfsberger Hütte localities in the southern Saualpe. Two-point isochrones from samples of Hohl and Wolfsberger Hütte based on one whole rock and one garnet separate yield ages of 99.2 ± 1.1 Ma and 101.7 ± 2 Ma, respectively. Two eclogite samples from Grünburgerbach give garnet-omphacite-whole rock ages of 100.3 ± 1 Ma and 101.79 ± 0.92 Ma, identical within error. The garnets in the eclogite from Hohl display a homogenous composition with no zoning of major elements, whereas the garnets of the samples from Grünburgerbach show an enrichment of Mn in the cores and lower contents towards the rims, which indicates prograde garnet growth during increasing P and T. The ages are therefore related to burial during subduction. These new Lu-Hf garnet ages are slightly older than the Lu-Hf garnet age data from Pohorje (~95 Ma; Sandmann et al. 2011, Thöni et al. 2008), which also date burial. If Koralpe/Saualpe and Pohorje would belong to one continuous crustal unit subducted and exhumed "en bloc" in a southeast-dipping subduction zone, the opposite age difference would be expected. Our results show that this is not the case and represent important constraints for a more realistic kinematic model. Janak, M

  17. Pyrite framboid diameter distribution in the Lower Oligocene black shales of the Vrancea Nappe as an indicator of changes in redox conditions, Eastern Outer Carpathians, Romania

    NASA Astrophysics Data System (ADS)

    Wendorff, Małgorzata; Marynowski, Leszek; Rospondek, Mariusz

    2016-04-01

    Studies of recent and ancient sediments revealed that the diameter distribution of pyrite framboids may be reliably used to characterise oxygen-restricted environments and distinguish ancient euxinic conditions (water column hydrogen sulphide bearing thus oxygen-free) from anoxic, non-sulfidic or dysoxic (oxygen-poor) conditions. Such diagnoses are of great importance when reconstructing palaeoenvironments in ancient basins and the processes of source rocks formation. During Oligocene to early Miocene time an extensive accumulation of organic matter (OM)-rich sediments occurred in the entire Paratethys including the Carpathian Foredeep, which was closed forming fold-thrust belt of the Outer Carpathians. These OM-rich black shales are represented by so-called Menilite shales, widely considered as hydrocarbon source rocks, which constitute as well a detailed archive for palaeoenvironmental changes. The purpose of this preliminary study is to characterise the depositional environment of the Lower Oligocene black shales basing on the pyrite framboid diameter distribution. Five samples of finely laminated black shales were selected from the Nechit section outcropping in the Bistrica half-window of the Vrancea Nappe in the Eastern Outer Carpathians, E Romania. At least 100 framboid diameters were measured on polished blocks using scanning electron microscope in a back-scattered electron mode. Framboids from four samples starting from the lowermost part of the section exhibit a narrow range of diameters from 1.0 to 11.5 μm; mean value ranges from 3.65 to 4.85 μm. Small-sized framboids (< 6 μm) account for 70% up to 91% of all framboids, while large framboids (>10 μm) are absent or rare (max. 2%). Within the sample from the uppermost part of the section framboids reveal more variable sizes, 2 - 25 μm, with mean value of 6.63 μm. Small framboids are still numerous (54%), however the amount of framboids >10 μm increases to 15%. The domination of small framboids with

  18. The ophiolite of the Eohellenic nappe in the island of Skyros, Greece: Geotectonic environment of formation and metamorphic conditions inferred by mineralogical and geochemical data

    NASA Astrophysics Data System (ADS)

    Karkalis, Christos; Magganas, Andreas; Koutsovitis, Petros

    2014-05-01

    The island of Skyros is located in the Sporades-Aegean region. It includes an ophiolitic mélange sequence consisting of serpentinites, gabbroic and doleritic rocks, and also lavas which mostly appear in massive form, but in rare cases as deformed pillows. The ophiolitic mélange sequence also includes rodingites, ophicalcites, as well as radiolarites. This formation belongs to the Eohellenic tectonic nappe, which encompasses marbles, sandstones and schists and was emplaced onto the Pelagonian Zone during Early Cretaceous [1, 2]. Serpentinites were most likely formed after serpentinization of harzburgitic protoliths and consist of serpentine, bastite, spinel and magnetite. The chemistry of spinels (TiO2=0.14-0.25 wt.%, Al2O3=35.1-35.21 wt.%, Cr#=37.38-38.87), shows that the harzburgitic protoliths plausibly resemble back-arc basin peridotites [3]. Gabbros and dolerites present mostly subophitic textures, between the hornblende/clinopyroxene and plagioclase grains. Based upon their petrography and on their mineral chemistry hornblendes have been distinguished into magmatic and metamorphic hornblendes, with the first occurring mostly in gabbroic rocks. Magmatic hornblendes exhibit relatively high TiO2 (1.42-1.62 wt.%), Al2O3 (5.11-5.86 wt.%) and Na2O (1.01-1.09 wt.%) contents, with their presence implying that the magma was at least to some degree hydrous. Lavas are tholeiitic basalts with relatively high FeOt≡12 wt.% and low K2O and Th contents, consisting mostly albite, altered clinopyroxene and devitrified glass. Tectonomagmatic discrimination diagrams [4, 5] illustrate that the studied gabbros and lavas of Skyros are most likely associated with SSZ processes. Gabbroic rocks, subvolcanic dolerites and lavas have been subjected to greenschist/subgreenschist metamorphic processes, as confirmed by the presence of secondary amphiboles (metamorphic hornblende, actinolite/tremolite), epidote, pumpellyite and chlorite in all of the studied samples. On the other hand

  19. Coupling of Oceanic and Continental Crust During Eocene Eclogite-Facies Metamorphism: Evidence From the Monte Rosa Nappe, Western Alps, Italy

    NASA Astrophysics Data System (ADS)

    Lapen, T. J.; Johnson, C. M.; Baumgartner, L. P.; Skora, S.; Mahlen, N. J.; Beard, B. L.

    2006-12-01

    Subduction of continental crust to HP-UHP metamorphic conditions requires overcoming density contrasts that are unfavorable to deep burial, whereas exhumation of these rocks can be reasonably explained through buoyancy-assisted transport in the subduction channel to more shallow depths. In the western Alps, both continental and oceanic lithosphere has been subducted to eclogite-facies metamorphic conditions. The burial and exhumation histories of these sections of lithosphere bear directly on the dynamics of subduction and the stacking of units within the subduction channel. We address the burial history of the continental crust with high precision U-Pb rutile and Lu-Hf garnet geochronology of the eclogite-facies Monte Rosa nappe (MR), western Alps, Italy. U-Pb rutile ages from quartz-carbonate-white mica-rutile veins that are hosted within eclogite and schist of the MR, Gressoney Valley, Italy, indicate that it was at eclogite-facies metamorphic conditions at 42.6 +/- 0.6 Ma. The sample area (Indren glacier, Furgg zone; Dal Piaz, 2001) consists of eclogite boudins that are surrounded by micaceous schist. Associated with the eclogite and schist are quartz-carbonate-white mica-rutile veins that formed in tension cracks in the eclogite and along the contact between eclogite and surrounding schist. Intrusion of the veins occurred at eclogite-facies metamorphic conditions (480-570°C, >1.3-1.4 GPa) based on textural relations, oxygen isotope thermometry, and geothermobarometry. Lu-Hf geochronology of garnet from a chloritoid-talc-garnet-phengite-quartz-calcite-pyrite - chalcopyrite bearing boudin within talc-chloritoid whiteschists of the MR, Val d'Ayas, Italy (Chopin and Monie, 1984; Pawlig, 2001) yields an age of 40.54 +/- 0.36 Ma. The talc-chloritoid whiteschists from the area record pressures and temperatures of 1.6-2.4 GPa and 500-530°C (Chopin and Monie, 1984; Le Bayon et al., 2006) indicating near UHP metamorphic conditions. Based on the age, P-T, and textural

  20. The Continent-Ocean Transition in the Mid-Norwegian Margin: Insight From Seismic Data and the Onshore Caledonian Analogue in the Seve Nappe Complex

    NASA Astrophysics Data System (ADS)

    Abdelmalak, Mansour M.; Planke, Sverre; Andersen, Torgeir B.; Faleide, Jan Inge; Corfu, Fernando; Tegner, Christian; Myklebust, Reidun

    2015-04-01

    The continental breakup and initial seafloor spreading in the NE Atlantic was accompanied by widespread intrusive and extrusive magmatism and the formation of conjugate volcanic passive margins. These margins are characterized by the presence of seaward dipping reflectors (SDR), an intense network of mafic sheet intrusions of the continental crust and adjacent sedimentary basins and a high-velocity lower crustal body. Nevertheless many issues remain unclear regarding the structure of volcanic passive margins; in particular the transitional crust located beneath the SDR.New and reprocessed seismic reflection data on the Mid-Norwegian margin allow a better sub-basalt imaging of the transitional crust located beneath the SDR. Different high-amplitude reflections with abrupt termination and saucer shaped geometries are identified and interpreted as sill intrusions. Other near vertical and inclined reflections are interpreted as dykes or dyke swarms. We have mapped the extent of the dyke reflections along the volcanic margin. The mapping suggests that the dykes represent the main feeder system for the SDR. The identification of saucer shaped sills implies the presence of sediments in the transitional zone beneath the volcanic sequences. Onshore exposures of Precambrian basement of the eroded volcanic margin in East Greenland show that, locally, the transitional crust is highly intruded by dykes and intrusive complexes with an increasing intensity of the plumbing and dilatation of the continental crust ocean-ward. Another well exposed analogue for a continent-ocean transitional crust is located within the Seve Nappe Complex (SNC) of the Scandinavian Caledonides. The best-preserved parts of SNC in the Pårte, Sarek, Kebnekaise, Abisko, and Indre Troms mountains are composed mainly of meta-sandstones and shales (now hornfelses) truncated typically by mafic dykes. At Sarek and Pårte, the dykes intrude the sedimentary rocks of the Favoritkammen Group, with a dyke density up

  1. Simulation of runoff and recharge and estimation of constituent loads in runoff, Edwards aquifer recharge zone (outcrop) and catchment area, Bexar County, Texas, 1997-2000

    USGS Publications Warehouse

    Ockerman, Darwin J.

    2002-01-01

    The U.S. Geological Survey developed a watershed model (Hydrological Simulation Program?FORTRAN) to simulate runoff and recharge and to estimate constituent loads in surface-water runoff in the Edwards aquifer recharge zone (outcrop) and catchment area in Bexar County, Texas. Rainfall and runoff data collected during 1970?98 from four gaged basins in the outcrop and catchment area were used to calibrate and test the model. The calibration parameters were applied in simulations of the four calibration basins and six ungaged basins that compose the study area to obtain runoff and recharge volumes for 4 years, 1997?2000. In 1997, simulated runoff from the study area was 5.62 inches. Simulated recharge in the study area was 7.85 inches (20 percent of rainfall). In 1998, simulated runoff was 11.05 inches; simulated recharge was 10.99 inches (25 percent of rainfall). In 1999, simulated runoff was 0.66 inch; simulated recharge was 3.03 inches (19 percent of rainfall). In 2000, simulated runoff was 5.29 inches; simulated recharge was 7.19 inches (21 percent of rainfall). During 1997?2000, direct infiltration of rainfall accounted for about 56 percent of the total Edwards aquifer recharge in Bexar County. Streamflow losses contributed about 37 percent of the recharge; flood impoundment contributed 7 percent. The simulated runoff volumes were used with event-mean-concentration data from basins in the study area and from other Bexar County basins to compute constituent loads and yields for various land uses. Annual loads for suspended solids, dissolved solids, dissolved nitrite plus nitrate nitrogen, and total lead were consistently largest from undeveloped land and smallest from commercial land or transportation corridors. Annual loads and yields varied with rainfall, with the maximum loads produced in the wettest year (1998) and the minimum loads produced in the driest year (1999).

  2. Rechargeable thin film battery and method for making the same

    DOEpatents

    Goldner, Ronald B.; Liu, Te-Yang; Goldner, Mark A.; Gerouki, Alexandra; Haas, Terry E.

    2006-01-03

    A rechargeable, stackable, thin film, solid-state lithium electrochemical cell, thin film lithium battery and method for making the same is disclosed. The cell and battery provide for a variety configurations, voltage and current capacities. An innovative low temperature ion beam assisted deposition method for fabricating thin film, solid-state anodes, cathodes and electrolytes is disclosed wherein a source of energetic ions and evaporants combine to form thin film cell components having preferred crystallinity, structure and orientation. The disclosed batteries are particularly useful as power sources for portable electronic devices and electric vehicle applications where high energy density, high reversible charge capacity, high discharge current and long battery lifetimes are required.

  3. Rechargeable battery which combats shape change of the zinc anode

    NASA Technical Reports Server (NTRS)

    Cohn, E. M. (Inventor)

    1976-01-01

    A rechargeable cell or battery is provided in which shape change of the zinc anode is combatted by profiling the ionic conductivity of the paths between the electrodes. The ion flow is greatest at the edges of the electrodes and least at the centers, thereby reducing migration of the zinc ions from edges to the center of the anode. A number of embodiments are disclosed in which the strength and/or amount of electrolyte, and/or the number and/or size of the paths provided by the separator between the electrodes, are varied to provide the desired ionic conductivity profile.

  4. A 65 Ah rechargeable lithium molybdenum disulfide battery

    NASA Technical Reports Server (NTRS)

    Brandt, K.

    1986-01-01

    A rechargeable lithium molybdenum disulfide battery which has a number of superior performance characteristics which includes a high energy density, a high power density, and a long charge retention time was developed. The first cell sizes developed included a C size cell and an AA size cell. Over the last two years, a project to demonstrate the feasibility of the scale up to this technology to a BC size cell with 65 Ah capacity was undertaken. The objective was to develop, build, and test a .6 kWh storage battery consisting of 6 BC cells in series.

  5. Using Tracer Tests to Estimate Vertical Recharge and Evaluate Influencing Factors for Irrigated Agricultural Systems

    NASA Astrophysics Data System (ADS)

    Lin, D.; Jin, M.; Brusseau, M.; Ma, B.; Liu, Y.

    2013-12-01

    Accurate estimation of vertical groundwater recharge is critical for (semi) arid regions, especially in places such as the North China Plain where vertical recharge comprises the largest portion of recharge. Tracer tests were used to estimate vertical recharge beneath agricultural systems irrigated by groundwater, and to help delineate factors that influence recharge. Bromide solution was applied to trace infiltration in the vadose zone beneath irrigated agricultural fields (rotated winter wheat and summer maize, orchards, and cotton) and non-irrigated woodlands at both piedmont plain (Shijiazhaung) and alluvial and lacustrine plains (Hengshui) in the North China Plain. The tracer tests lasted for more than two years, and were conducted at a total of 37 sites. Tracer solution was injected into the subsurface at a depth of 1.2 m before the rainy season. Soil samples were then collected periodically to observe bromide transport and estimate recharge rates at the point-scale. For these experiments, the only irrigation the fields received was that applied by the landowners. In addition to these tests, a controlled irrigation experiment was conducted at a single wheat and maize site. The results showed that recharge rates were lower for the alluvial and lacustrine plains sites, which comprise finer-textured soils than those present in the piedmont plain. Specifically, the recharge rate ranged between 56-466 mm/a beneath wheat-maize, 110-564 mm/a beneath orchard, and 0-21 mm/a beneath woodlands with an average recharge coefficient of 0.17 for the piedmont plain sites, while the recharge rate ranged between 26-165 mm/a beneath wheat-maize, 6-40 mm/a beneath orchard, 87-319 mm/a beneath cotton, and 0-32 mm/a beneath woodlands with an average recharge coefficient of 0.10 for the alluvial and lacustrine plain sites. Irrigation provided the primary contribution to recharge, with precipitation providing a minor contribution. The results of both the uncontrolled and controlled

  6. Ground-water recharge in Escambia and Santa Rosa Counties, Florida

    USGS Publications Warehouse

    Grubbs, J.W.

    1995-01-01

    Ground water is a major component of Florida's water resources, accounting for 90 percent of all public-supply and self-supplied domestic water withdrawals, and 58 percent of self-supplied commercial-industrial and agricultural withdrawals of freshwater (Marella, 1992). Ground-water is also an important source of water for streams, lakes, and wetlands in Florida. Because of their importance, a good understanding of these resources is essential for their sound development, use, and protection. One area in which our understanding is lacking is in characterizing the rate at which ground water in aquifers is recharged, and how recharge rates vary geographically. Ground-water recharge (recharge) is the replenishment of ground water by downward infiltration of water from rainfall, streams, and other sources (American Society of Civil Engineers, 1987, p. 222). The recharge rates in many areas of Florida are unknown, of insufficient accuracy, or mapped at scales that are too coarse to be useful. Improved maps of recharge rates will result in improved capabilities for managing Florida's ground-water resources. In 1989, the U.S. Geological Survey, in cooperation with the Florida Department of Environmental Regulation, began a study to delineate high-rate recharge areas in several regions of Florida (Vecchioli and others, 1990). This study resulted in recharge maps that delineated areas of high (greater than 10 inches per year) and low (0 to 10 inches per year) recharge in three counties--Okaloosa, Pasco, and Volusia Counties--at a scale of 1:100,000. This report describes the results of a similar recharge mapping study for Escambia and Santa Rosa Counties (fig. 1), in which areas of high- and low-rates of recharge to the sand-and-gravel aquifer and Upper Floridan aquifer are delineated. The study was conducted in 1992 and 1993 by the U.S. Geological Survey in cooperation with the Florida Department of Environmental Protection.

  7. Present-day groundwater recharge estimation in parts of the Indian Sub-Continent

    NASA Astrophysics Data System (ADS)

    Bhanja, S. N.; Mukherjee, A.; Wada, Y.; Scanlon, B. R.; Taylor, R. G.; Rodell, M.; Malakar, P.

    2015-12-01

    Large part of global population has been dependent on groundwater as a source of fresh water. The demand would further increase with increasing population and stress associated with climate change. We tried to provide regional-scale groundwater recharge estimates in a large part of Indian Sub-Continent. A combination of ground-based, satellite-based and numerical model simulated recharge estimates were presented in the densely populated region. Three different methods: an intense network of observational wells (n>13,000 wells), a satellite (TRMM) and global land-surface model (CLM) outputs, and a global-scale hydrological model (PCR GLOBWB) were employed to calculate recharge estimates. Groundwater recharge values exhibit large spatial variations over the entire region on the basis of aquifer hydrogeology, precipitation and groundwater withdrawal patterns. Groundwater recharge estimates from all three estimation techniques were found to be higher (>300 mm/year) in fertile planes of Indus-Ganges-Brahmaputra (IGB) river basins. A combination of favorable hydrogeologic conditions (porosity, permeability etc.), comparatively higher rates of precipitation, and return flow from rapidly withdrawn irrigation water might influence occurrence of high recharge rates. However, central and southern study area experiences lower recharge rates (<200 mm/year), might be associated with unfavorable hydrogeologic conditions associated with cratonic provinces. Statistical analysis of inter-comparison between the three different recharge estimates show good matches in some of the areas. Recharge estimates indicate dynamic nature of groundwater recharge as a function of precipitation, land use pattern, and hydrogeologic parameters. On a first hand basis, the estimates will help policy makers to understand groundwater recharge process over the densely populated region and finally would facilitate to implement sustainable policy for securing water security.

  8. Using 14C and 3H to understand groundwater flow and recharge in an aquifer window

    NASA Astrophysics Data System (ADS)

    Atkinson, A. P.; Cartwright, I.; Gilfedder, B. S.; Cendón, D. I.; Unland, N. P.; Hofmann, H.

    2014-12-01

    Knowledge of groundwater residence times and recharge locations is vital to the sustainable management of groundwater resources. Here we investigate groundwater residence times and patterns of recharge in the Gellibrand Valley, southeast Australia, where outcropping aquifer sediments of the Eastern View Formation form an "aquifer window" that may receive diffuse recharge from rainfall and recharge from the Gellibrand River. To determine recharge patterns and groundwater flow paths, environmental isotopes (3H, 14C, δ13C, δ18O, δ2H) are used in conjunction with groundwater geochemistry and continuous monitoring of groundwater elevation and electrical conductivity. The water table fluctuates by 0.9 to 3.7 m annually, implying recharge rates of 90 and 372 mm yr-1. However, residence times of shallow (11 to 29 m) groundwater determined by 14C are between 100 and 10 000 years, 3H activities are negligible in most of the groundwater, and groundwater electrical conductivity remains constant over the period of study. Deeper groundwater with older 14C ages has lower δ18O values than younger, shallower groundwater, which is consistent with it being derived from greater altitudes. The combined geochemistry data indicate that local recharge from precipitation within the valley occurs through the aquifer window, however much of the groundwater in the Gellibrand Valley predominantly originates from the regional recharge zone, the Barongarook High. The Gellibrand Valley is a regional discharge zone with upward head gradients that limits local recharge to the upper 10 m of the aquifer. Additionally, the groundwater head gradients adjacent to the Gellibrand River are generally upwards, implying that it does not recharge the surrounding groundwater and has limited bank storage. 14C ages and Cl concentrations are well correlated and Cl concentrations may be used to provide a first-order estimate of groundwater residence times. Progressively lower chloride concentrations from 10

  9. Using 14C and 3H to understand groundwater flow and recharge in an aquifer window

    NASA Astrophysics Data System (ADS)

    Atkinson, A. P.; Cartwright, I.; Gilfedder, B. S.; Cendón, D. I.; Unland, N. P.; Hofmann, H.

    2014-06-01

    Knowledge of groundwater residence times and recharge locations are vital to the sustainable management of groundwater resources. Here we investigate groundwater residence times and patterns of recharge in the Gellibrand Valley, southeast Australia, where outcropping aquifer sediments of the Eastern View Formation form an "aquifer window" that may receive diffuse recharge and recharge from the Gellibrand River. To determine recharge patterns and groundwater flowpaths, environmental isotopes (3H, 14C, δ13C, δ18O, δ2H) are used in conjunction with groundwater geochemistry and continuous monitoring of groundwater elevation and electrical conductivity. Despite the water table fluctuating by 0.9-3.7 m annually producing estimated recharge rates of 90 and 372 mm yr-1, residence times of shallow (11-29 m) groundwater determined by 14C ages are between 100 and 10 000 years. 3H activities are negligible in most of the groundwater and groundwater electrical conductivity in individual areas remains constant over the period of study. Although diffuse local recharge is evident, the depth to which it penetrates is limited to the upper 10 m of the aquifer. Rather, groundwater in the Gellibrand Valley predominantly originates from the regional recharge zone, the Barongarook High, and acts as a regional discharge zone where upward head gradients are maintained annually, limiting local recharge. Additionally, the Gellibrand River does not recharge the surrounding groundwater and has limited bank storage. 14C ages and Cl concentrations are well correlated and Cl concentrations may be used to provide a first-order estimate of groundwater residence times. Progressively lower chloride concentrations from 10 000 years BP to the present day are interpreted to indicate an increase in recharge rates on the Barongarook High.

  10. Predicting Groundwater Recharge for the Okanagan Basin: A Little HELP From the Locals

    NASA Astrophysics Data System (ADS)

    Liggett, J. E.; Toews, M. W.; Smerdon, B. D.; Allen, D. M.

    2007-12-01

    Estimates of groundwater recharge are an essential component in flow models; however, recharge is highly uncertain and difficult to quantify for dry regions. Since flow models are often used in water management planning, acquiring spatially variable recharge estimates at a comparable scale can be challenging. Regional scale recharge estimates must reflect trends of local scale processes to be effective in planning. This study examined how results from a regional recharge model compared to recharge estimated in separate, local scale models from opposing ends of the Okanagan basin, in British Columbia, Canada. At nearly 8000~km2, the north-south trending basin has a climatic gradient with a warmer, wetter climate in the north and hotter, drier conditions in the south. The region has become a popular area for tourism, residence, and agriculture, particularly orchards and vineyards. With surface water sources close to fully allocated, the region is turning to groundwater as a means to support increasing socioeconomic growth. Basin wide (regional) recharge estimates in the valley bottom are a critical step in managing groundwater resources. Regional estimates of recharge were determined with the Hydrologic Evaluation of Landfill Performance (HELP) code by establishing common areas of soil texture, water table depth and three other hydrologic parameters. Results from the regional scale were compared with two independently derived, local scale estimates of groundwater recharge. For the south Okanagan, regional estimates were compared with results from a high-resolution integrated HELP and MODFLOW analysis; and in the north Okanagan, regional estimates were compared to results from a study utilizing the Richards equation based MIKE-SHE code. Comparison with these two models, calculated in areas at each end of the climatic gradient, provide confidence in developing a map of regional groundwater recharge. Preliminary results illustrate the applicability of HELP for

  11. Modeled impacts of predicted climate change on recharge and groundwater levels

    NASA Astrophysics Data System (ADS)

    Scibek, J.; Allen, D. M.

    2006-11-01

    A methodology is developed for linking climate models and groundwater models to investigate future impacts of climate change on groundwater resources. An unconfined aquifer, situated near Grand Forks in south central British Columbia, Canada, is used to test the methodology. Climate change scenarios from the Canadian Global Coupled Model 1 (CGCM1) model runs are downscaled to local conditions using Statistical Downscaling Model (SDSM), and the change factors are extracted and applied in LARS-WG stochastic weather generator and then input to the recharge model. The recharge model simulated the direct recharge to the aquifer from infiltration of precipitation and consisted of spatially distributed recharge zones, represented in the Hydrologic Evaluation of Landfill Performance (HELP) hydrologic model linked to a geographic information system (GIS). A three-dimensional transient groundwater flow model, implemented in MODFLOW, is then used to simulate four climate scenarios in 1-year runs (1961-1999 present, 2010-2039, 2040-2069, and 2070-2099) and compare groundwater levels to present. The effect of spatial distribution of recharge on groundwater levels, compared to that of a single uniform recharge zone, is much larger than that of temporal variation in recharge, compared to a mean annual recharge representation. The predicted future climate for the Grand Forks area from the downscaled CGCM1 model will result in more recharge to the unconfined aquifer from spring to the summer season. However, the overall effect of recharge on the water balance is small because of dominant river-aquifer interactions and river water recharge.

  12. Sensitivity of ground - water recharge estimates to climate variability and change, Columbia Plateau, Washington

    USGS Publications Warehouse

    Vaccaro, John J.

    1992-01-01

    The sensitivity of groundwater recharge estimates was investigated for the semiarid Ellensburg basin, located on the Columbia Plateau, Washington, to historic and projected climatic regimes. Recharge was estimated for predevelopment and current (1980s) land use conditions using a daily energy-soil-water balance model. A synthetic daily weather generator was used to simulate lengthy sequences with parameters estimated from subsets of the historical record that were unusually wet and unusually dry. Comparison of recharge estimates corresponding to relatively wet and dry periods showed that recharge for predevelopment land use varies considerably within the range of climatic conditions observed in the 87-year historical observation period. Recharge variations for present land use conditions were less sensitive to the same range of historical climatic conditions because of irrigation. The estimated recharge based on the 87-year historical climatology was compared with adjustments to the historical precipitation and temperature records for the same record to reflect CO2-doubling climates as projected by general circulation models (GCMs). Two GCM scenarios were considered: an average of conditions for three different GCMs with CO2 doubling, and a most severe “maximum” case. For the average GCM scenario, predevelopment recharge increased, and current recharge decreased. Also considered was the sensitivity of recharge to the variability of climate within the historical and adjusted historical records. Predevelopment and current recharge were less and more sensitive, respectively, to the climate variability for the average GCM scenario as compared to the variability within the historical record. For the maximum GCM scenario, recharge for both predevelopment and current land use decreased, and the sensitivity to the CO2-related climate change was larger than sensitivity to the variability in the historical and adjusted historical climate records.

  13. Natural water purification and water management by artificial groundwater recharge

    PubMed Central

    Balke, Klaus-Dieter; Zhu, Yan

    2008-01-01

    Worldwide, several regions suffer from water scarcity and contamination. The infiltration and subsurface storage of rain and river water can reduce water stress. Artificial groundwater recharge, possibly combined with bank filtration, plant purification and/or the use of subsurface dams and artificial aquifers, is especially advantageous in areas where layers of gravel and sand exist below the earth’s surface. Artificial infiltration of surface water into the uppermost aquifer has qualitative and quantitative advantages. The contamination of infiltrated river water will be reduced by natural attenuation. Clay minerals, iron hydroxide and humic matter as well as microorganisms located in the subsurface have high decontamination capacities. By this, a final water treatment, if necessary, becomes much easier and cheaper. The quantitative effect concerns the seasonally changing river discharge that influences the possibility of water extraction for drinking water purposes. Such changes can be equalised by seasonally adapted infiltration/extraction of water in/out of the aquifer according to the river discharge and the water need. This method enables a continuous water supply over the whole year. Generally, artificially recharged groundwater is better protected against pollution than surface water, and the delimitation of water protection zones makes it even more save. PMID:18357624

  14. Impact of Large-scale Geological Architectures On Recharge

    NASA Astrophysics Data System (ADS)

    Troldborg, L.; Refsgaard, J. C.; Engesgaard, P.; Jensen, K. H.

    Geological and hydrogeological data constitutes the basis for assessment of ground- water flow pattern and recharge zones. The accessibility and applicability of hard ge- ological data is often a major obstacle in deriving plausible conceptual models. Nev- ertheless focus is often on parameter uncertainty caused by the effect of geological heterogeneity due to lack of hard geological data, thus neglecting the possibility of alternative conceptualizations of the large-scale geological architecture. For a catchment in the eastern part of Denmark we have constructed different geologi- cal models based on different conceptualization of the major geological trends and fa- cies architecture. The geological models are equally plausible in a conceptually sense and they are all calibrated to well head and river flow measurements. Comparison of differences in recharge zones and subsequently well protection zones emphasize the importance of assessing large-scale geological architecture in hydrological modeling on regional scale in a non-deterministic way. Geostatistical modeling carried out in a transitional probability framework shows the possibility of assessing multiple re- alizations of large-scale geological architecture from a combination of soft and hard geological information.

  15. Organotrisulfide: A High Capacity Cathode Material for Rechargeable Lithium Batteries.

    PubMed

    Wu, Min; Cui, Yi; Bhargav, Amruth; Losovyj, Yaroslav; Siegel, Amanda; Agarwal, Mangilal; Ma, Ying; Fu, Yongzhu

    2016-08-16

    An organotrisulfide (RSSSR, R is an organic group) has three sulfur atoms which could be involved in multi-electron reduction reactions; therefore it is a promising electrode material for batteries. Herein, we use dimethyl trisulfide (DMTS) as a model compound to study its redox reactions in rechargeable lithium batteries. With the aid of XRD, XPS, and GC-MS analysis, we confirm DMTS could undergo almost a 4 e(-) reduction process in a complete discharge to 1.0 V. The discharge products are primarily LiSCH3 and Li2 S. The lithium cell with DMTS catholyte delivers an initial specific capacity of 720 mAh g(-1) DMTS and retains 82 % of the capacity over 50 cycles at C/10 rate. When the electrolyte/DMTS ratio is 3:1 mL g(-1) , the reversible specific energy for the cell including electrolyte can be 229 Wh kg(-1) . This study shows organotrisulfide is a promising high-capacity cathode material for high-energy rechargeable lithium batteries. PMID:27411083

  16. Tritium tracer test to estimate aquifer recharge under irrigated conditions

    NASA Astrophysics Data System (ADS)

    Jimenez-Martinez, J.; Tamoh, K.; Candela, L.

    2009-12-01

    Environmental tracers, as tritium, have been generally used to estimate aquifer recharge under natural conditions. A tritium tracer test to estimate recharge under semi-arid and irrigated conditions is presented. The test was carried out in an experimental plot under drip irrigation, located in SE Spain, with annual row crops (rotation lettuce and melon), following common agricultural practices in open air. Tritiated water was applied as an irrigation pulse, soil cores were taken at different depths and a liquid scintillation analyzer was used to measure the concentration of tritium in soil samples. Transport of tritium was simulated with SOLVEG code, a one-dimensional numerical model for simulating transport of heat, water and tritiated water in liquid and gas phase, which has been modified and adapted for this experience, including ground cover, root growth and root water uptake. One crop has been used to calibrate the modeling approach and other three crops to validate it. Results of flow and transport modelling show a good agreement between observed and estimated tritium concentration profile. For the period October 2007-September 2008, total drainage obtained value was 441 mm.

  17. Linking denitrification and infiltration rates during managed groundwater recharge.

    PubMed

    Schmidt, Calla M; Fisher, Andrew T; Racz, Andrew J; Lockwood, Brian S; Huertos, Marc Los

    2011-11-15

    We quantify relations between rates of in situ denitrification and saturated infiltration through shallow, sandy soils during managed groundwater recharge. We used thermal methods to determine time series of point-specific flow rates, and chemical and isotopic methods to assess denitrification progress. Zero order denitrification rates between 3 and 300 μmol L(-1) d(-1) were measured during infiltration. Denitrification was not detected at times and locations where the infiltration rate exceeded a threshold of 0.7 ± 0.2 m d(-1). Pore water profiles of oxygen and nitrate concentration indicated a deepening of the redoxocline at high flow rates, which reduced the thickness of the zone favorable for denitrification. Denitrification rates were positively correlated with infiltration rates below the infiltration threshold, suggesting that for a given set of sediment characteristics, there is an optimal infiltration rate for achieving maximum nitrate load reduction and improvements to water supply during managed groundwater recharge. The extent to which results from this study may be extended to other managed and natural hydrologic settings remains to be determined, but the approach taken in this study should be broadly applicable, and provides a quantitative link between shallow hydrologic and biogeochemical processes.

  18. Natural water purification and water management by artificial groundwater recharge.

    PubMed

    Balke, Klaus-Dieter; Zhu, Yan

    2008-03-01

    Worldwide, several regions suffer from water scarcity and contamination. The infiltration and subsurface storage of rain and river water can reduce water stress. Artificial groundwater recharge, possibly combined with bank filtration, plant purification and/or the use of subsurface dams and artificial aquifers, is especially advantageous in areas where layers of gravel and sand exist below the earth's surface. Artificial infiltration of surface water into the uppermost aquifer has qualitative and quantitative advantages. The contamination of infiltrated river water will be reduced by natural attenuation. Clay minerals, iron hydroxide and humic matter as well as microorganisms located in the subsurface have high decontamination capacities. By this, a final water treatment, if necessary, becomes much easier and cheaper. The quantitative effect concerns the seasonally changing river discharge that influences the possibility of water extraction for drinking water purposes. Such changes can be equalised by seasonally adapted infiltration/extraction of water in/out of the aquifer according to the river discharge and the water need. This method enables a continuous water supply over the whole year. Generally, artificially recharged groundwater is better protected against pollution than surface water, and the delimitation of water protection zones makes it even more save.

  19. Impact of Fire on Recharge at a Semiarid Site

    NASA Astrophysics Data System (ADS)

    Seyfried, M. S.; Murdock, M. D.

    2003-12-01

    The potential hazards and benefits of fire are critical issues in semiarid parts of the Western USA. The hydrologic impacts of fire, in terms of recharge, are poorly understood in the region. These impacts depend largely on the transpiration of the newly established, post-fire vegetation relative to that of the pre-fire vegetation. In this study we focus on two impacts of fire on vegetation, the reduction of leaf area index, which influences the rate of transpiration, and the potential reduction in effective rooting depth, which influences the amount of water transpired. The study site has a mean annual precipitation of about 550 mm with a native vegetation dominated by semiarid shrubs. For one season prior and one season following a prescribed fire we monitored leaf are index, soil water content, and soil water potential in adjacent burned and unburned plots. One year after the fire we have documented a substantial reduction in leaf area index and effective rooting depth. Simulations indicate that potential recharge after the fire increased by more than 50 mm per unit area. This result will vary considerably with location depending on environmental factors such as the soil depth and amount and season of precipitation.

  20. Feasibility of groundwater recharge dam projects in arid environments

    NASA Astrophysics Data System (ADS)

    Jaafar, H. H.

    2014-05-01

    A new method for determining feasibility and prioritizing investments for agricultural and domestic recharge dams in arid regions is developed and presented. The method is based on identifying the factors affecting the decision making process and evaluating these factors, followed by determining the indices in a GIS-aided environment. Evaluated parameters include results from field surveys and site visits, land cover and soils data, precipitation data, runoff data and modeling, number of beneficiaries, domestic irrigation demand, reservoir objectives, demography, reservoirs yield and reliability, dam structures, construction costs, and operation and maintenance costs. Results of a case study on more than eighty proposed dams indicate that assessment of reliability, annualized cost/demand satisfied and yield is crucial prior to investment decision making in arid areas. Irrigation demand is the major influencing parameter on yield and reliability of recharge dams, even when only 3 months of the demand were included. Reliability of the proposed reservoirs as related to their standardized size and net inflow was found to increase with increasing yield. High priority dams were less than 4% of the total, and less priority dams amounted to 23%, with the remaining found to be not feasible. The results of this methodology and its application has proved effective in guiding stakeholders for defining most favorable sites for preliminary and detailed design studies and commissioning.

  1. Organotrisulfide: A High Capacity Cathode Material for Rechargeable Lithium Batteries.

    PubMed

    Wu, Min; Cui, Yi; Bhargav, Amruth; Losovyj, Yaroslav; Siegel, Amanda; Agarwal, Mangilal; Ma, Ying; Fu, Yongzhu

    2016-08-16

    An organotrisulfide (RSSSR, R is an organic group) has three sulfur atoms which could be involved in multi-electron reduction reactions; therefore it is a promising electrode material for batteries. Herein, we use dimethyl trisulfide (DMTS) as a model compound to study its redox reactions in rechargeable lithium batteries. With the aid of XRD, XPS, and GC-MS analysis, we confirm DMTS could undergo almost a 4 e(-) reduction process in a complete discharge to 1.0 V. The discharge products are primarily LiSCH3 and Li2 S. The lithium cell with DMTS catholyte delivers an initial specific capacity of 720 mAh g(-1) DMTS and retains 82 % of the capacity over 50 cycles at C/10 rate. When the electrolyte/DMTS ratio is 3:1 mL g(-1) , the reversible specific energy for the cell including electrolyte can be 229 Wh kg(-1) . This study shows organotrisulfide is a promising high-capacity cathode material for high-energy rechargeable lithium batteries.

  2. Recharge and sustainability of a coastal aquifer in northern Albania

    NASA Astrophysics Data System (ADS)

    Kumanova, X.; Marku, S.; Fröjdö, S.; Jacks, G.

    2014-06-01

    The River Mati in Albania has formed a coastal plain with Holocene and Pleistocene sediments. The outer portion of the plain is clay, with three underlying aquifers that are connected to an alluvial fan at the entry of the river into the plain. The aquifers supply water for 240,000 people. Close to the sea the aquifers are brackish. The brackish water is often artesian and found to be thousands of years old. Furthermore, the salinity, supported by δ18O results, does not seem to be due to mixing with old seawater but due to diffusion from intercalated clay layers. Heavy metals from mines in the upstream section of River Mati are not an immediate threat, as the pH buffering of the river water is good. Moreover, the heavy metals are predominantly found in suspended and colloidal phases. Two sulphur isotope signatures, one mirroring seawater sulphate in the brackish groundwater (δ34S >21 ‰) and one showing the influence of sulphide in the river and the fresh groundwater (δ34S <10 ‰), indicate that the groundwater in the largest well field is recharged from the river. The most serious threat is gravel extraction in the alluvial fan, decreasing the hydraulic head necessary for recharge and causing clogging of sediments.

  3. The Li-ion rechargeable battery: a perspective.

    PubMed

    Goodenough, John B; Park, Kyu-Sung

    2013-01-30

    Each cell of a battery stores electrical energy as chemical energy in two electrodes, a reductant (anode) and an oxidant (cathode), separated by an electrolyte that transfers the ionic component of the chemical reaction inside the cell and forces the electronic component outside the battery. The output on discharge is an external electronic current I at a voltage V for a time Δt. The chemical reaction of a rechargeable battery must be reversible on the application of a charging I and V. Critical parameters of a rechargeable battery are safety, density of energy that can be stored at a specific power input and retrieved at a specific power output, cycle and shelf life, storage efficiency, and cost of fabrication. Conventional ambient-temperature rechargeable batteries have solid electrodes and a liquid electrolyte. The positive electrode (cathode) consists of a host framework into which the mobile (working) cation is inserted reversibly over a finite solid-solution range. The solid-solution range, which is reduced at higher current by the rate of transfer of the working ion across electrode/electrolyte interfaces and within a host, limits the amount of charge per electrode formula unit that can be transferred over the time Δt = Δt(I). Moreover, the difference between energies of the LUMO and the HOMO of the electrolyte, i.e., electrolyte window, determines the maximum voltage for a long shelf and cycle life. The maximum stable voltage with an aqueous electrolyte is 1.5 V; the Li-ion rechargeable battery uses an organic electrolyte with a larger window, which increase the density of stored energy for a given Δt. Anode or cathode electrochemical potentials outside the electrolyte window can increase V, but they require formation of a passivating surface layer that must be permeable to Li(+) and capable of adapting rapidly to the changing electrode surface area as the electrode changes volume during cycling. A passivating surface layer adds to the impedance of the

  4. The Li-ion rechargeable battery: a perspective.

    PubMed

    Goodenough, John B; Park, Kyu-Sung

    2013-01-30

    Each cell of a battery stores electrical energy as chemical energy in two electrodes, a reductant (anode) and an oxidant (cathode), separated by an electrolyte that transfers the ionic component of the chemical reaction inside the cell and forces the electronic component outside the battery. The output on discharge is an external electronic current I at a voltage V for a time Δt. The chemical reaction of a rechargeable battery must be reversible on the application of a charging I and V. Critical parameters of a rechargeable battery are safety, density of energy that can be stored at a specific power input and retrieved at a specific power output, cycle and shelf life, storage efficiency, and cost of fabrication. Conventional ambient-temperature rechargeable batteries have solid electrodes and a liquid electrolyte. The positive electrode (cathode) consists of a host framework into which the mobile (working) cation is inserted reversibly over a finite solid-solution range. The solid-solution range, which is reduced at higher current by the rate of transfer of the working ion across electrode/electrolyte interfaces and within a host, limits the amount of charge per electrode formula unit that can be transferred over the time Δt = Δt(I). Moreover, the difference between energies of the LUMO and the HOMO of the electrolyte, i.e., electrolyte window, determines the maximum voltage for a long shelf and cycle life. The maximum stable voltage with an aqueous electrolyte is 1.5 V; the Li-ion rechargeable battery uses an organic electrolyte with a larger window, which increase the density of stored energy for a given Δt. Anode or cathode electrochemical potentials outside the electrolyte window can increase V, but they require formation of a passivating surface layer that must be permeable to Li(+) and capable of adapting rapidly to the changing electrode surface area as the electrode changes volume during cycling. A passivating surface layer adds to the impedance of the

  5. Reconnaissance Estimates of Recharge Based on an Elevation-dependent Chloride Mass-balance Approach

    SciTech Connect

    Charles E. Russell; Tim Minor

    2002-08-31

    Significant uncertainty is associated with efforts to quantity recharge in arid regions such as southern Nevada. However, accurate estimates of groundwater recharge are necessary to understanding the long-term sustainability of groundwater resources and predictions of groundwater flow rates and directions. Currently, the most widely accepted method for estimating recharge in southern Nevada is the Maxey and Eakin method. This method has been applied to most basins within Nevada and has been independently verified as a reconnaissance-level estimate of recharge through several studies. Recharge estimates derived from the Maxey and Eakin and other recharge methodologies ultimately based upon measures or estimates of groundwater discharge (outflow methods) should be augmented by a tracer-based aquifer-response method. The objective of this study was to improve an existing aquifer-response method that was based on the chloride mass-balance approach. Improvements were designed to incorporate spatial variability within recharge areas (rather than recharge as a lumped parameter), develop a more defendable lower limit of recharge, and differentiate local recharge from recharge emanating as interbasin flux. Seventeen springs, located in the Sheep Range, Spring Mountains, and on the Nevada Test Site were sampled during the course of this study and their discharge was measured. The chloride and bromide concentrations of the springs were determined. Discharge and chloride concentrations from these springs were compared to estimates provided by previously published reports. A literature search yielded previously published estimates of chloride flux to the land surface. {sup 36}Cl/Cl ratios and discharge rates of the three largest springs in the Amargosa Springs discharge area were compiled from various sources. This information was utilized to determine an effective chloride concentration for recharging precipitation and its associated uncertainty via Monte Carlo simulations

  6. Peste des petits ruminants.

    PubMed

    Parida, S; Muniraju, M; Mahapatra, M; Muthuchelvan, D; Buczkowski, H; Banyard, A C

    2015-12-14

    Peste des petits ruminants virus causes a highly infectious disease of small ruminants that is endemic across Africa, the Middle East and large regions of Asia. The virus is considered to be a major obstacle to the development of sustainable agriculture across the developing world and has recently been targeted by the World Organisation for Animal Health (OIE) and the Food and Agriculture Organisation (FAO) for eradication with the aim of global elimination of the disease by 2030. Fundamentally, the vaccines required to successfully achieve this goal are currently available, but the availability of novel vaccine preparations to also fulfill the requisite for differentiation between infected and vaccinated animals (DIVA) may reduce the time taken and the financial costs of serological surveillance in the later stages of any eradication campaign. Here, we overview what is currently known about the virus, with reference to its origin, updated global circulation, molecular evolution, diagnostic tools and vaccines currently available to combat the disease. Further, we comment on recent developments in our knowledge of various recombinant vaccines and on the potential for the development of novel multivalent vaccines for small ruminants.

  7. Peste des petits ruminants.

    PubMed

    Parida, S; Muniraju, M; Mahapatra, M; Muthuchelvan, D; Buczkowski, H; Banyard, A C

    2015-12-14

    Peste des petits ruminants virus causes a highly infectious disease of small ruminants that is endemic across Africa, the Middle East and large regions of Asia. The virus is considered to be a major obstacle to the development of sustainable agriculture across the developing world and has recently been targeted by the World Organisation for Animal Health (OIE) and the Food and Agriculture Organisation (FAO) for eradication with the aim of global elimination of the disease by 2030. Fundamentally, the vaccines required to successfully achieve this goal are currently available, but the availability of novel vaccine preparations to also fulfill the requisite for differentiation between infected and vaccinated animals (DIVA) may reduce the time taken and the financial costs of serological surveillance in the later stages of any eradication campaign. Here, we overview what is currently known about the virus, with reference to its origin, updated global circulation, molecular evolution, diagnostic tools and vaccines currently available to combat the disease. Further, we comment on recent developments in our knowledge of various recombinant vaccines and on the potential for the development of novel multivalent vaccines for small ruminants. PMID:26443889

  8. Peste des petits ruminants

    PubMed Central

    Parida, S.; Muniraju, M.; Mahapatra, M.; Muthuchelvan, D.; Buczkowski, H.; Banyard, A.C.

    2015-01-01

    Peste des petits ruminants virus causes a highly infectious disease of small ruminants that is endemic across Africa, the Middle East and large regions of Asia. The virus is considered to be a major obstacle to the development of sustainable agriculture across the developing world and has recently been targeted by the World Organisation for Animal Health (OIE) and the Food and Agriculture Organisation (FAO) for eradication with the aim of global elimination of the disease by 2030. Fundamentally, the vaccines required to successfully achieve this goal are currently available, but the availability of novel vaccine preparations to also fulfill the requisite for differentiation between infected and vaccinated animals (DIVA) may reduce the time taken and the financial costs of serological surveillance in the later stages of any eradication campaign. Here, we overview what is currently known about the virus, with reference to its origin, updated global circulation, molecular evolution, diagnostic tools and vaccines currently available to combat the disease. Further, we comment on recent developments in our knowledge of various recombinant vaccines and on the potential for the development of novel multivalent vaccines for small ruminants. PMID:26443889

  9. MODIS-aided statewide net groundwater-recharge estimation in Nebraska.

    PubMed

    Szilagyi, Jozsef; Jozsa, Janos

    2013-01-01

    Monthly evapotranspiration (ET) rates (2000 to 2009) across Nebraska at about 1-km resolution were obtained by linear transformations of the MODIS (MODerate resolution Imaging Spectroradiometer) daytime surface temperature values with the help of the Priestley-Taylor equation and the complementary relationship of evaporation. For positive values of the mean annual precipitation and ET differences, the mean annual net recharge was found by an additional multiplication of the power-function-transformed groundwater vulnerability DRASTIC-code values. Statewide mean annual net recharge became about 29 mm (i.e., 5% of mean annual precipitation) with the largest recharge rates (in excess of 100 mm/year) found in the eastern Sand Hills and eastern Nebraska. Areas with the largest negative net recharge rates caused by declining groundwater levels due to large-scale irrigation are found in the south-western region of the state. Error bounds of the estimated values are within 10% to 15% of the corresponding precipitation rates and the estimated net recharge rates are sensitive to errors in the precipitation and ET values. This study largely confirms earlier base-flow analysis-based statewide groundwater recharge estimates when considerations are made for differences in the recharge definitions. The current approach not only provides better spatial resolution than available earlier studies for the region but also quantifies negative net recharge rates that become especially important in numerical modeling of shallow groundwater systems. PMID:23216050

  10. Promoting the Market for Plug-in Hybrid and Battery Electric Vehicles: Role of Recharge Availability

    SciTech Connect

    Lin, Zhenhong; Greene, David L

    2012-01-01

    Much recent attention has been drawn to providing adequate recharge availability as a means to promote the battery electric vehicle (BEV) and plug-in hybrid electric vehicle (PHEV) market. The possible role of improved recharge availability in developing the BEV-PHEV market and the priorities that different charging options should receive from the government require better understanding. This study reviews the charging issue and conceptualizes it into three interactions between the charge network and the travel network. With travel data from 3,755 drivers in the National Household Travel Survey, this paper estimates the distribution among U.S. consumers of (a) PHEV fuel-saving benefits by different recharge availability improvements, (b) range anxiety by different BEV ranges, and (c) willingness to pay for workplace and public charging in addition to home recharging. With the Oak Ridge National Laboratory MA3T model, the impact of three recharge improvements is quantified by the resulting increase in BEV-PHEV sales. Compared with workplace and public recharging improvements, home recharging improvement appears to have a greater impact on BEV-PHEV sales. The impact of improved recharging availability is shown to be amplified by a faster reduction in battery cost.

  11. Ground-water recharge near Santa Fe, north-central New Mexico

    USGS Publications Warehouse

    Anderholm, S.K.

    1994-01-01

    Recharge to the basin-fill aquifer near Santa Fe, New Mexico, was investigated using chloride mass-balance methods. Chloride concentrations in water in the unsaturated zone indicate no recharge in areas where runoff and flooding do not occur. The mass of chloride stored in the upper part of the unsaturated zone in these areas would take about 6,000 to 8,000 years to accumulate, assuming the present (1989) chloride fluxes. Chloride concen- trations in water in the unsaturated zone beneath arroyo channels indicate that recharge does occur in these areas; chloride concentrations in this recharge water at two sites ranged from 40 to 60 milligrams per liter. Estimates of mountain-front recharge using a chloride balance in drainage basins are about 2,320 acre-feet per year in the Santa Fe River drainage, 690 acre-feet per year in the Rio Tesuque drainage, and 830 acre-feet per year in the Anoyo Hondo drainage. Stable isotopes of hydrogen and oxygen indicate that little summer precipitation recharges the ground-water system and that winter precipitation results in most of the recharge water. Most hydrogen and oxygen isotope data for ground water in the area coincide with the local meteoric water line on a graph showing the relation between oxygen and hydrogen in ground water. This indicates that, on the basis of the hydrogen and oxygen isotopic composition of ground water and precipi- tation, evaporation of recharge water or ground water does not occur.

  12. MODIS-aided statewide net groundwater-recharge estimation in Nebraska.

    PubMed

    Szilagyi, Jozsef; Jozsa, Janos

    2013-01-01

    Monthly evapotranspiration (ET) rates (2000 to 2009) across Nebraska at about 1-km resolution were obtained by linear transformations of the MODIS (MODerate resolution Imaging Spectroradiometer) daytime surface temperature values with the help of the Priestley-Taylor equation and the complementary relationship of evaporation. For positive values of the mean annual precipitation and ET differences, the mean annual net recharge was found by an additional multiplication of the power-function-transformed groundwater vulnerability DRASTIC-code values. Statewide mean annual net recharge became about 29 mm (i.e., 5% of mean annual precipitation) with the largest recharge rates (in excess of 100 mm/year) found in the eastern Sand Hills and eastern Nebraska. Areas with the largest negative net recharge rates caused by declining groundwater levels due to large-scale irrigation are found in the south-western region of the state. Error bounds of the estimated values are within 10% to 15% of the corresponding precipitation rates and the estimated net recharge rates are sensitive to errors in the precipitation and ET values. This study largely confirms earlier base-flow analysis-based statewide groundwater recharge estimates when considerations are made for differences in the recharge definitions. The current approach not only provides better spatial resolution than available earlier studies for the region but also quantifies negative net recharge rates that become especially important in numerical modeling of shallow groundwater systems.

  13. Importance of unsaturated zone flow for simulating recharge in a humid climate

    USGS Publications Warehouse

    Hunt, R.J.; Prudic, D.E.; Walker, J.F.; Anderson, M.P.

    2008-01-01

    Transient recharge to the water table is often not well understood or quantified. Two approaches for simulating transient recharge in a ground water flow model were investigated using the Trout Lake watershed in north-central Wisconsin: (1) a traditional approach of adding recharge directly to the water table and (2) routing the same volume of water through an unsaturated zone column to the water table. Areas with thin (less than 1 m) unsaturated zones showed little difference in timing of recharge between the two approaches; when water was routed through the unsaturated zone, however, less recharge was delivered to the water table and more discharge occurred to the surface because recharge direction and magnitude changed when the water table rose to the land surface. Areas with a thick (15 to 26 m) unsaturated zone were characterized by multimonth lags between infiltration and recharge, and, in some cases, wetting fronts from precipitation events during the fall overtook and mixed with infiltration from the previous spring snowmelt. Thus, in thicker unsaturated zones, the volume of water infiltrated was properly simulated using the traditional approach, but the timing was different from simulations that included unsaturated zone flow. Routing of rejected recharge and ground water discharge at land surface to surface water features also provided a better simulation of the observed flow regime in a stream at the basin outlet. These results demonstrate that consideration of flow through the unsaturated zone may be important when simulating transient ground water flow in humid climates with shallow water tables.

  14. Importance of unsaturated zone flow for simulating recharge in a humid climate.

    PubMed

    Hunt, Randall J; Prudic, David E; Walker, John F; Anderson, Mary P

    2008-01-01

    Transient recharge to the water table is often not well understood or quantified. Two approaches for simulating transient recharge in a ground water flow model were investigated using the Trout Lake watershed in north-central Wisconsin: (1) a traditional approach of adding recharge directly to the water table and (2) routing the same volume of water through an unsaturated zone column to the water table. Areas with thin (less than 1 m) unsaturated zones showed little difference in timing of recharge between the two approaches; when water was routed through the unsaturated zone, however, less recharge was delivered to the water table and more discharge occurred to the surface because recharge direction and magnitude changed when the water table rose to the land surface. Areas with a thick (15 to 26 m) unsaturated zone were characterized by multimonth lags between infiltration and recharge, and, in some cases, wetting fronts from precipitation events during the fall overtook and mixed with infiltration from the previous spring snowmelt. Thus, in thicker unsaturated zones, the volume of water infiltrated was properly simulated using the traditional approach, but the timing was different from simulations that included unsaturated zone flow. Routing of rejected recharge and ground water discharge at land surface to surface water features also provided a better simulation of the observed flow regime in a stream at the basin outlet. These results demonstrate that consideration of flow through the unsaturated zone may be important when simulating transient ground water flow in humid climates with shallow water tables.

  15. Quantifying ground water recharge at multiple scales using PRMS and GIS.

    PubMed

    Cherkauer, Douglas S

    2004-01-01

    Management of ground water resources requires a method to calculate demonstrably accurate recharge rates at local to regional scales using readily available information bases. Many methods are available to calculate recharge, but most are unable to satisfy all these conditions. A distributed parameter model is shown to meet the stated needs. Such models are input intensive, however, so a procedure to define most inputs from GIS and hydrogeological sources is presented. It simplifies the PRMS calibration observed streamflow hydrographs by reducing degrees of freedom from dozens to four. For seven watersheds (60 to 500 km2), the GIS-aided calibrations have average errors of 5% on recharge and 2% on total streamflow, verifying the accuracy of the process. Recharge is also calculated for 63 local-scale subwatersheds (average size 37 km2). For the study area, calculated recharges average 11 cm/yr. Soil and rock conductivity, porosity, and depth to the water table are shown to be the physical properties which dominate the spatial variability of recharge. The model has been extended to uncalibrated watersheds where GIS and climatic information are known. It reproduces total annual discharge and recharge to within 9% and 10%, respectively, indicating the process can also be used to calculate recharge in ungauged watersheds. It has not been tested outside the study area, however.

  16. Recharge Rates and Chemistry Beneath Playas of the High Plains Aquifer - A Literature Review and Synthesis

    USGS Publications Warehouse

    Gurdak, Jason J.; Roe, Cassia D.

    2009-01-01

    Playas are ephemeral, closed-basin wetlands that are important zones of recharge to the High Plains (or Ogallala) aquifer and critical habitat for birds and other wildlife in the otherwise semiarid, shortgrass prairie and agricultural landscape. The ephemeral nature of playas, low regional recharge rates, and a strong reliance on ground water from the High Plains aquifer has prompted many questions regarding the contribution of recharge from playas to the regional aquifer. To address these questions and concerns, the U.S. Geological Survey, in cooperation with the Playa Lakes Joint Venture, present a review and synthesis of the more than 175 publications about recharge rates and chemistry beneath playas and interplaya settings. Although a number of questions remain regarding the controls on recharge rates and chemistry beneath playas, the results from most published studies indicate that recharge rates beneath playas are substantially (1 to 2 orders of magnitude) higher than recharge rates beneath interplaya settings. The synthesis presented here supports the conceptual model that playas are important zones of recharge to the High Plains aquifer and are not strictly evaporative pans. The major findings of this synthesis yield science-based implications for the protection and management of playas and ground-water resources of the High Plains aquifer and directions for future research.

  17. Seasonality of Groundwater Recharge in the Basin and Range Province, Western North America

    NASA Astrophysics Data System (ADS)

    Neff, K. L.; Meixner, T.; Ajami, H.; De La Cruz, L.

    2015-12-01

    For water-scarce communities in the western U.S., it is critical to understand groundwater recharge regimes and how those regimes might shift in the face of climate change and impact groundwater resources. Watersheds in the Basin and Range Geological Province are characterized by a variable precipitation regime of wet winters and variable summer precipitation. The relative contributions to groundwater recharge by summer and winter precipitation vary throughout the province, with winter precipitation recharge dominant in the northern parts of the region, and recharge from summer monsoonal precipitation playing a more significant role in the south, where the North American Monsoon (NAM) extends its influence. Stable water isotope data of groundwater and seasonal precipitation from sites in Sonora, Mexico and the U.S. states of California, Nevada, Utah, Arizona, Colorado, New Mexico, and Texas were examined to estimate and compare groundwater recharge seasonality throughout the region. Contributions of winter precipitation to annual recharge vary from 69% ± 41% in the southernmost Río San Miguel Basin in Sonora, Mexico, to 100% ± 36% in the westernmost Mojave Desert of California. The Normalized Seasonal Wetness Index (NSWI), a simple water budget method for estimating recharge seasonality from climatic data, was shown to approximate recharge seasonality well in several winter precipitation-dominated systems, but less well in basins with significant summer precipitation.

  18. PROSPECTS FOR ENHANCED GROUNDWATER RECHARGE VIA INFILTRATION OF URBAN STORMWATER RUNOFF: A CASE STUDY

    EPA Science Inventory

    The rain garden is an urban storm water best management practice that is used to infiltrate runoff close to its source, thereby disconnecting impervious area while providing an avenue for groundwater recharge. Groundwater recharge may provide additional benefits to aquatic ecosys...

  19. Estimating natural recharge in San Gorgonio Pass watersheds, California, 1913–2012

    USGS Publications Warehouse

    Hevesi, Joseph A.; Christensen, Allen H.

    2015-12-21

    The SGPWM was used to simulate a 100-year water budget, including recharge and runoff, for water years 1913 through 2012. Results indicated that most recharge came from episodic infiltration of surface-water runoff in the larger stream channels. Results also indicated periods of great variability in recharge and runoff in response to variability in precipitation. More recharge was simulated for the area of the groundwater basin underlying the more permeable alluvial fill of the valley floor compared to recharge in the neighboring upland areas of the less permeable mountain blocks. The greater recharge was in response to the episodic streamflow that discharged from the mountain block areas and quickly infiltrated the permeable alluvial fill of the groundwater basin. Although precipitation at the higher altitudes of the mountain block was more than double precipitation at the lower altitudes of the valley floor, recharge for inter-channel areas of the mountain block was limited by the lower permeability bedrock underlying the thin soil cover, and most of the recharge in the mountain block was limited to the main stream channels underlain by alluvial fill.

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

    USGS Publications Warehouse

    Nimmo, John R.; Horowittz, 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.

  1. Entropy based groundwater monitoring network design considering spatial distribution of annual recharge

    NASA Astrophysics Data System (ADS)

    Leach, James M.; Coulibaly, Paulin; Guo, Yiping

    2016-10-01

    This study explores the inclusion of a groundwater recharge based design objective and the impact it has on the design of optimum groundwater monitoring networks. The study was conducted in the Hamilton, Halton, and Credit Valley regions of Ontario, Canada, in which the existing Ontario Provincial Groundwater Monitoring Network was augmented with additional monitoring wells. The Dual Entropy-Multiobjective Optimization (DEMO) model was used in these analyses. The value of using this design objective is rooted in the information contained within the estimated recharge. Recharge requires knowledge of climate, geomorphology, and geology of the area, thus using this objective function can help account for these physical characteristics. Two sources of groundwater recharge data were examined and compared, the first was calculated using the Precipitation-Runoff Modeling System (PRMS), and the second was an aggregation of recharge found using both the PRMS and Hydrological Simulation Program-Fortran (HSP-F). The entropy functions are used to identify optimal trade-offs between the maximum information content and the minimum shared information between the monitoring wells. The recharge objective will help to quantify hydrological characteristics of the vadose zone, and thus provide more information to the optimization algorithm. Results show that by including recharge as a design objective, the spatial coverage of the monitoring network can be improved. The study also highlights the flexibility of DEMO and its ability to incorporate additional design objectives such as the groundwater recharge.

  2. A ROOT ZONE MODELLING APPROACH TO ESTIMATING GROUNDWATER RECHARGE FROM IRRIGATED AREAS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In irrigated semi-arid and arid regions, accurate knowledge of groundwater recharge is important for the sustainable management of scarce water resources. The Campo de Cartagena area of southeast Spain is a semi-arid region where irrigation return flow accounts for a substantial portion of recharge....

  3. Estimation of recharge from irrigation flows; Analysis of field and laboratory data and modeling.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This work is aimed at quantifying aquifer recharge due to irrigation in the Campo de Cartagena (SE Spain). A study of recharge was conducted on an experiment plot cropped in lettuce and irrigated with a drip system. The physico-chemical and hydraulic properties of the vadose zone were characterized ...

  4. Pathogen Decay during Managed Aquifer Recharge at Four Sites with Different Geochemical Characteristics and Recharge Water Sources.

    PubMed

    Sidhu, J P S; Toze, S; Hodgers, L; Barry, K; Page, D; Li, Y; Dillon, P

    2015-09-01

    Recycling of stormwater water and treated effluent via managed aquifer recharge (MAR) has often been hampered because of perceptions of low microbiological quality of recovered water and associated health risks. The goal of this study was to assess the removal of selected pathogens in four large-scale MAR schemes and to determine the influence of aquifer characteristics, geochemistry, and type of recharge water on the pathogen survival times. Bacterial pathogens tested in this study had the shortest one log removal time (, <3 d), followed by oocysts (, <120 d), with enteric viruses having the biggest variability in removal times (, 18 to >200 d). Human adenovirus and rotavirus were relatively persistent under anaerobic conditions (, >200 d). Human adenovirus survived longer than all the other enteric virus tested in the study and hence could be used as a conservative indicator for virus removal in groundwater during MAR. The results suggest that site-specific subsurface conditions such as groundwater chemistry can have considerable influence on the decay rates of enteric pathogens and that viruses are likely to be the critical pathogens from a public health perspective. PMID:26436258

  5. Spatio-temporal recharge patterns in a semi-arid alluvial basin with irrigated crops

    NASA Astrophysics Data System (ADS)

    Ruud, N. C.; Harter, T.; Naugle, A. W.

    2001-12-01

    Recharge in semi-arid regions with irrigated crops is predominantly driven by irrigation technology and cropping patterns, but also by the seasonal distribution of rainfall and the availability of irrigation water. A significant amount of basin recharge occurs from ephemeral streams and unlined irrigation canals. A spatially distributed, GIS-based hydrologic model of water application and water use at the land-atmosphere interface was developed to estimate transient recharge to the deep vadose zone and into the unconfined alluvial aquifer. The spatial basis for the hydrologic model are individual landuse units (diffuse recharge) and a network of streams and canals with water seepage (lineal recharge). The land-atmosphere interface and unsaturated zone model component (LAIUZ) is coupled to a surface water supply model component (SWSM) that provides surface water deliveries by district or sub-district, depending on available information. Using LAIUZ and SWSM, we investigate the regional behavior and spatio-temporal variability of deep vadose zone recharge in the 3,800 square kilometer Tule groundwater basin of the San Joaquin Valley, California. Surface water management in the topographically flat basin is divided between two dozen irrigation and water districts. All surface water is imported or is natural discharge into the basin. Groundwater extractions are managed by landowners on a field-by-field basis. Monthly varying recharge and groundwater pumping rates are computed for the hydrologic years 1970 through 2000. The average size of the GIS landuse units is 0.4 sq. kilometers. The GIS coverage distinguishes over 60 landuse types. Applied and consumptive water use are computed based on actual evapotranspiration and known irrigation or water use efficiencies for each landuse unit. Seepage from streams is computed by mass balance. The resulting model estimates of groundwater recharge and pumping are in good agreement with measured groundwater level changes for the

  6. Climate Impact on Groundwater Recharge in Southeastern Louisiana and Southwestern Mississippi

    NASA Astrophysics Data System (ADS)

    Beigi, E.; Tsai, F. T.

    2012-12-01

    Increases of concentrations of CO2 and other greenhouse gases have a significant effect on global climate, precipitation and hydrology, which in turn influences recharge to aquifers. Groundwater recharge study is imperative to the sole source aquifer, for example the Southern Hills aquifer system in southeastern Louisiana and southwestern Mississippi, which provides more than 50 percent of the drinking water consumed in the area overlying the aquifer and has no substitute drinking water source(s). To trace the climate impact and its consequent groundwater availability, this study developed a GIS-based integrated framework to connect climate models to a high-resolution hydrologic model to quantify long-term groundwater recharge. We employed the Hydrologic Evaluation of Landfill Performance (HELP3) model as our hydrologic model to estimate spatial-temporal distribution of potential recharge for a regional scale. HELP3 model was especially suitable for our recharge study due to Louisiana humid climate and the use of a regional-scale water budget approach. Detailed surficial soil property and land cover were obtained from the NRCS and the USGS to derive maps of curve number for the HELP3 model. Wireline well logs and drillers logs were analyzed to determine stratigraphic lithology and the first major sand encountered beneath the soil layer. For a regional scale, we used global circulation model (GCM) downscaled daily precipitation and temperature obtained from USGS CASCaDE Project Climate Data as the forcing input to the HELP3 model. The emission scenarios considered in this study were A2, B1 and A1FI from Parallel Climate Model 1 (PCM) and from the NOAA Geophysical Fluid Dynamics Lab's GFDL CM2.1 model. We used the computed runoff from USGS WaterWatch along with the HELP3 model to calculate the recharge index (RI) and delineate the recharge index map for individual hydrologic units in terms of Hydrologic Unit Codes (HUCs). The recharge index was defined as the

  7. Groundwater recharge mechanisms inferred from isoscapes in a complex tropical mountainous region

    NASA Astrophysics Data System (ADS)

    Sánchez-Murillo, Ricardo; Birkel, Christian

    2016-05-01

    Stable isotope variations and groundwater recharge mechanisms remain poorly understood across the tropics, particularly in Central America. Here stable isotopes (δ18O and δ2H) in groundwater, surface water, and rainfall are used to produce high-resolution (100 m2 grid) isoscapes for Costa Rica, from which an isotope ratio of precipitation to groundwater (P/GW) is estimated to elucidate the dominant groundwater recharge processes. Spatially, groundwater and surface water isotope ratios depict the strong orographic separation into the Caribbean and Pacific slopes induced by moisture transport directly from the Caribbean Sea and the eastern tropical Pacific Ocean. P/GW isotope ratios reveal that groundwater recharge is biased toward intensive and more depleted monthly rainfall across the Pacific slope with clear evidence of secondary evaporation indicating slower soil matrix recharge processes. On the other hand, P/GW isotope ratios indicate a weak influence of secondary evaporation across the Caribbean slope suggesting rapid recharge via preferential flow paths.

  8. Geochemical Signature of Natural Water Recharge in the Jungar Basin and Its Response to Climate.

    PubMed

    Zhu, Bingqi; Yu, Jingjie; Rioual, Patrick

    2016-01-01

    This paper analyzed the physico-chemical characteristics of natural waters in a drainage system of the Jungar Basin, northwestern China to identify chemical evolution and recharge mechanisms of natural waters in an arid environment. The waters studied are different in mineralization, but are typically carbonate rivers and alkaline in nature. No Cl-dominated water type occurs, indicating an early stage of water evolution. Regolith and geomorphological parameters controlling ground-surface temperature may play a large role in the geological evolution of the water. Three main morphological and hydrological units are reflected in water physico-chemistry. Climate influences the salinization of natural waters substantially. Direct recharge from seasonal snow and ice-melt water and infiltration of rain to the ground are significant recharge processes for natural waters, but recharge from potential deep groundwater may be less important. The enrichment of ions in lakes has been mainly caused by evaporation rather than through the quality change of the recharged water.

  9. Identification of potential artificial groundwater recharge zones in Northwestern Saudi Arabia using GIS and Boolean logic

    NASA Astrophysics Data System (ADS)

    Zaidi, Faisal K.; Nazzal, Yousef; Ahmed, Izrar; Naeem, Muhammad; Jafri, Muhammad Kamran

    2015-11-01

    Identifying potential groundwater recharge zones is a pre-requisite for any artificial recharge project. The present study focuses on identifying the potential zones of Artificial Groundwater Recharge (AGR) in Northwestern Saudi Arabia. Parameters including slope, soil texture, vadose zone thickness, groundwater quality (TDS) and type of water bearing formation were integrated in a GIS environment using Boolean logic. The results showed that 17.90% of the total studied area is suitable for AGR. The identified zones were integrated with the land use/land cover map to avoid agricultural and inhabited lands which reduced the total potential area to 14.24%. Geomorphologically the wadi beds are the most suitable sites for recharge. On the basis of the potential AGR zones closeness to the available recharge water supply (rain water, desalinated sea water and treated waste water) the potential zones were classified as Category A (high priority) and Category B (low priority).

  10. Groundwater recharge to the Gulf Coast aquifer system in Montgomery and Adjacent Counties, Texas

    USGS Publications Warehouse

    Oden, Timothy D.; Delin, Geoffrey N.

    2013-01-01

    Simply stated, groundwater recharge is the addition of water to the groundwater system. Most of the water that is potentially available for recharging the groundwater system in Montgomery and adjacent counties in southeast Texas moves relatively rapidly from land surface to surface-water bodies and sustains streamflow, lake levels, and wetlands. Recharge in southeast Texas is generally balanced by evapotranspiration, discharge to surface waters, and the downward movement of water into deeper parts of the groundwater system; however, this balance can be altered locally by groundwater withdrawals, impervious surfaces, land use, precipitation variability, or climate, resulting in increased or decreased rates of recharge. Recharge rates were compared to the 1971–2000 normal annual precipitation measured Cooperative Weather Station 411956, Conroe, Tex.

  11. 3H and 14C as tracers of ground-water recharge

    USGS Publications Warehouse

    Izbicki, John A.; Michel, Robert L.; Martin, Peter

    1992-01-01

    Surface spreading of water from the Santa Clara River is used to recharge aquifers underlying the Oxnard Plain. These aquifers are divided into an upper system about 400 feet thick, and a lower system more than 1,000 feet thick. In previous studies, it has been reported that surface spreading recharged aquifers in both the upper and lower systems. Water from most wells perforated in the upper system has tritium levels consistent with decay-corrected concentrations found in water recharged after 1952 when tritium levels increased as a result of atmospheric testing of nuclear weapons. Water from most wells in the lower system does not contain measurable tritium and must have been recharged prior to 1952. Carbon-14 ages estimated for water from wells in the lower system range from recent to about 25,000 years before present. These data show that the lower system is not effectively recharged by surface spreading.

  12. Zeolite in horizontal permeable reactive barriers for artificial groundwater recharge

    NASA Astrophysics Data System (ADS)

    Leal, María; Martínez-Hernández, Virtudes; Lillo, Javier; Meffe, Raffaella; de Bustamante, Irene

    2013-04-01

    The Spanish Water Reuse Royal Decree 1620/2007 considers groundwater recharge as a feasible use of reclaimed water. To achieve the water quality established in the above-mentioned legislation, a tertiary wastewater treatment is required. In this context, the infiltration of effluents generated by secondary wastewater treatments through a Horizontal Permeable Reactive Barrier (HPRB) may represent a suitable regeneration technology. Some nutrients (phosphate and ammonium) and some Pharmaceutical and Personal Care Products (PPCPs) are not fully removed in conventional wastewater treatment plants. To avoid groundwater contamination when effluents of wastewater treatments plants are used in artificial recharge activities, these contaminants have to be removed. Due to its sorption capacities, zeolite is among the most used reactive materials in Permeable Reactive Barrier (PRB). Therefore, the main goal of this study is to evaluate the zeolite retention effectiveness of nutrients and PPCPs occurring in treated wastewater. Batch sorption experiments using synthetic wastewater (SWW) and zeolite were performed. A 1:4 zeolite/SWW ratio was selected due to the high sorption capacity of the reactive material.The assays were carried out by triplicate. All the bottles containing the SWW-zeolite mixture were placed on a mechanical shaker during 24 hours at 140 rpm and 25 °C. Ammonium and phosphate, as main nutrients, and a group of PPCPs were selected as compounds to be tested during the experiments. Nutrients were analyzed by ion chromatography. For PPCPs determination, Solid Phase Extraction (SPE) was applied before their analysis by liquid chromatography-mass spectrometry time of flight (LC-MS/ TOF). The experimental data were fitted to linearized Langmuir and Freundlich isotherm equations to obtain sorption parameters. In general, Freundlich model shows a greater capability of reproducing experimental data. To our knowledge, sorption of the investigated compounds on zeolite

  13. Use of Constructed Wetlands for Polishing Recharge Wastewater

    NASA Astrophysics Data System (ADS)

    Cardwell, W.

    2009-12-01

    The use of constructed wetlands for waste water treatment is becoming increasingly popular as more focus is being shifted to natural means of waste treatment. These wetlands employ processes that occur naturally and effectively remove pollutants and can greatly minimize costs when compared to full scale treatment plants. Currently, wetland design is based on basic “rules-of-thumb,” meaning engineers have a general understanding but not necessarily a thorough knowledge of the intricate physical, biological, and chemical processes involved in these systems. Furthermore, there is very little consideration given to use the wetland as a recharge pond to allow the treated water to percolate and recharge the local groundwater aquifers. The City of Foley, located in Alabama, and the Utilities Board of the City of Foley partnered with Wolf Bay Watershed Watch to evaluate alternative wastewater effluent disposal schemes. Rather than discharging the treated water into a local stream, a pilot program has been developed to allow water from the treatment process to flow into a constructed wetlands area where, after natural treatment, the treated water will then be allowed to percolate into a local unconfined aquifer. The goal of this study is to evaluate how constructed wetlands can be used for “polishing” effluent as well as how this treated water might be reused. Research has shown that constructed wetlands, with proper design and construction elements, are effective in the treatment of BOD, TSS, nitrogen, phosphorous, pathogens, metals, sulfates, organics, and other substances commonly found in wastewater. Mesocosms will be used to model the wetland, at a much smaller scale, in order to test and collect data about the wetland treatment capabilities. Specific objectives include: 1. Determine optimum flow rates for surface flow wetlands where water treatment is optimized. 2. Evaluate the capabilities of constructed wetlands to remove/reduce common over the counter

  14. Temporal and spatial variability of groundwater recharge on Jeju Island, Korea

    USGS Publications Warehouse

    Mair, Alan; Hagedorn, Benjamin; Tillery, Suzanne; El-Kadi, Aly I.; Westenbroek, Stephen; Ha, Kyoochul; Koh, Gi-Won

    2013-01-01

    Estimates of groundwater recharge spatial and temporal variability are essential inputs to groundwater flow models that are used to test groundwater availability under different management and climate conditions. In this study, a soil water balance analysis was conducted to estimate groundwater recharge on the island of Jeju, Korea, for baseline, drought, and climate-land use change scenarios. The Soil Water Balance (SWB) computer code was used to compute groundwater recharge and other water balance components at a daily time step using a 100 m grid cell size for an 18-year baseline scenario (1992–2009). A 10-year drought scenario was selected from historical precipitation trends (1961–2009), while the climate-land use change scenario was developed using late 21st century climate projections and a change in urban land use. Mean annual recharge under the baseline, drought, and climate-land use scenarios was estimated at 884, 591, and 788 mm, respectively. Under the baseline scenario, mean annual recharge was within the range of previous estimates (825–959 mm) and only slightly lower than the mean of 902 mm. As a fraction of mean annual rainfall, mean annual recharge was computed as only 42% and less than previous estimates of 44–48%. The maximum historical reported annual pumping rate of 241 × 106 m3 equates to 15% of baseline recharge, which is within the range of 14–16% computed from earlier studies. The model does not include a mechanism to account for additional sources of groundwater recharge, such as fog drip, irrigation, and artificial recharge, and may also overestimate evapotranspiration losses. Consequently, the results presented in this study represent a conservative estimate of total recharge.

  15. Impacts of thickening unsaturated zone on groundwater recharge in the North China Plain

    NASA Astrophysics Data System (ADS)

    Cao, Guoliang; Scanlon, Bridget R.; Han, Dongmei; Zheng, Chunmiao

    2016-06-01

    Unsustainable groundwater development shown by rapid groundwater depletion in the North China Plain (NCP) underscores the need to quantify spatiotemporal variability in groundwater recharge for improved management of the resource. The objective of this study was to assess spatiotemporal variability in recharge in response to thickening of the unsaturated zone in the NCP. Recharge was estimated by linking a soil water balance (SWB) model, on the basis of monthly meteorological data, irrigation applications, and soil moisture monitoring data (1993-2008), to the water table using a deep unsaturated zone flow model. The dynamic bottom boundary (water table) position was provided by the saturated zone flow component, which simulates regional pumping. The model results clearly indicate the effects of unsaturated zone thickening on both temporal distribution and magnitude of recharge: smoothing temporal variability in recharge, and increasing unsaturated storage and lag time between percolation and recharge. The thickening unsaturated zone can result in average recharge reduction of up to ∼70% in loam soils with water table declines ⩾30 m. Declining groundwater levels with irrigation sourced by groundwater converts percolation to unsaturated zone storage, averaging 14 mm equivalent water depth per year in mostly loam soil over the study period, accounting for ∼30% of the saturated groundwater storage depletion. This study demonstrates that, in thickening unsaturated zones, modeling approaches that directly equate deep drainage with recharge will overestimate the amount and underestimate the time lag between percolation and recharge, emphasizing the importance of more realistic simulation of the continuity of unsaturated and saturated storage to provide more reliable estimates of spatiotemporal variability in recharge.

  16. Variations in climate and ephemeral channel recharge in southeastern Arizona, United States

    USGS Publications Warehouse

    Pool, D.R.

    2005-01-01

    [1] Significant variations in interannual and decadal recharge rates are likely in alluvial basins of the semiarid southwestern United States on the basis of decadal variations in climate and precipitation and correlation of El Nin??o with high rates of winter precipitation and streamflow. A better understanding of the magnitude of recharge variations in semiarid and arid regions would reduce water budget uncertainty. Variability of ephemeral channel recharge with climate in southeastern Arizona was investigated through analysis of hydrologic monitoring near three ephemeral streams in southeastern Arizona during the middle to late 1990s and by relating the results to long-term hydrologic and climatic trends. The analysis used precipitation, streamflow, water levels in wells, estimates of groundwater storage change from repeat gravity surveys, and two climatic indicators of El Nin??o-Southern Oscillation (ENSO), Southern Oscillation index, and Pacific Decadal Oscillation (PDO). Results indicate that variations in winter recharge are related to ENSO. El Nin??o conditions correspond with a greater probability of high rates of winter precipitation, streamflow, and recharge. La Nin??a conditions are almost exclusively associated with below-average recharge. Rates of recharge along Rillito Creek near Tucson during 1977-1998, a period of frequent El Nin??o conditions and positive PDO values, were 3 times recharge rates during 1941-1957, a period dominated by La Nin??a conditions and low PDO values. Quantification of recharge variability with decadal climate cycles should improve estimates of rates of aquifer drainage and replenishment in the region. Similar methods are applicable to other regions where thick unsaturated zones can accept significant periodic recharge.

  17. Chloride-mass-balance for predicting increased recharge after land-use change

    SciTech Connect

    Gee, G.W.; Zhang, Z.F.; Tyler, S.W.; Albright, W.H.; Singleton, M.J.

    2004-02-23

    The chloride-mass-balance (CMB) method has been used extensively to estimate recharge in arid and semi-arid environments. Required data include estimates of annual precipitation, total chloride input (from dry fallout and precipitation), and pore-water chloride concentrations. Typically, CMB has been used to estimate ancient recharge but recharge from recent land-use change has also been documented. Recharge rates below a few mm/yr are reliably detected with CMB; however, estimates above a few mm/yr appear to be less reliable. We tested the CMB method against 26 years of drainage from a 7.6-m-deep lysimeter at a simulated waste-burial ground, located on the Department of Energy s Hanford Site in southeastern Washington State, USA where land-use change has increased recharge rates. Measured drainage from the lysimeter for the past 26 years averaged 62 mm/yr. Precipitation averaged 190 mm/yr with an estimated chloride input of 0.225 mg/L. Initial pore-water chloride concentration was 88 mg/L and decreased to about 6 mg/L after 26 years, while the drainage water decreased to less than 1 mg/L. A recharge estimate made using chloride concentrations in drain water was within 20 percent of the measured drainage rate. In contrast, recharge estimates using 1:1 (water: soil) extracts were lower than actual by factors ranging from 2 to 8 or more. The results suggest that when recharge is above a few mm/yr, soil water extracts can lead to unreliable estimates of recharge. For conditions of elevated recharge, direct sampling of pore water is the preferred method, because chloride concentrations are often 20 to 50 times higher in directly-sampled pore water than in pore-water extracts.

  18. Comparison of local- to regional-scale estimates of ground-water recharge in Minnesota, USA

    USGS Publications Warehouse

    Delin, G.N.; Healy, R.W.; Lorenz, D.L.; Nimmo, J.R.

    2007-01-01

    Regional ground-water recharge estimates for Minnesota were compared to estimates made on the basis of four local- and basin-scale methods. Three local-scale methods (unsaturated-zone water balance, water-table fluctuations (WTF) using three approaches, and age dating of ground water) yielded point estimates of recharge that represent spatial scales from about 1 to about 1000 m2. A fourth method (RORA, a basin-scale analysis of streamflow records using a recession-curve-displacement technique) yielded recharge estimates at a scale of 10–1000s of km2. The RORA basin-scale recharge estimates were regionalized to estimate recharge for the entire State of Minnesota on the basis of a regional regression recharge (RRR) model that also incorporated soil and climate data. Recharge rates estimated by the RRR model compared favorably to the local and basin-scale recharge estimates. RRR estimates at study locations were about 41% less on average than the unsaturated-zone water-balance estimates, ranged from 44% greater to 12% less than estimates that were based on the three WTF approaches, were about 4% less than the age dating of ground-water estimates, and were about 5% greater than the RORA estimates. Of the methods used in this study, the WTF method is the simplest and easiest to apply. Recharge estimates made on the basis of the UZWB method were inconsistent with the results from the other methods. Recharge estimates using the RRR model could be a good source of input for regional ground-water flow models; RRR model results currently are being applied for this purpose in USGS studies elsewhere.

  19. Measurement of groundwater recharge on eastern Long Island, New York, U.S.A.

    NASA Astrophysics Data System (ADS)

    Steenhuis, Tammo S.; Jackson, Craig D.; Kung, Samuel K. J.; Brutsaert, Wilfried

    1985-07-01

    Two methods were tested for their suitability to provide improved estimates of recharge in the region of eastern Long Island. The two methods tested consist, first, of measuring recharge with a direct application of Darcy's law in the vadose zone and, second, of calculating recharge by closure of the hydrologic budget equation with evaporation computed from micrometeorologic data. The recharge figure, now in general use, of 50% of the annual precipitation is a long-term average at best. Our measurements of recharge, which were performed during a three-year period, showed that the vertical flux past the 1 m depth was strongly dependent on both the time of the year and the precipitation amount. In late fall, winter and early spring a high percentage of the precipitation became recharge. During the summer months there was a small net upward movement of water past the 1 m depth. Precipitation during these months did not contribute to the annual recharge. It may be concluded from our measurements that in order to estimate recharge, special attention should be given to precipitation during the winter months. A better estimate for annual recharge than the current 50% of annual precipitation might be to take approximately 75-90% of the precipitation from October 15 until May 15. The two methods used for estimating recharge were labour intensive and required experienced technicians. Currently, one method cannot be recommended above the other. Both methods give a good estimate during the year except for the winter. The closure method using micrometeorological data gives a slightly higher estimate than the direct measurement method based on Darcy's law.

  20. Spatial and temporal variability of ground water recharge in central Australia: a tracer approach.

    PubMed

    Harrington, Glenn A; Cook, Peter G; Herczeg, Andrew L

    2002-01-01

    Two environmental tracer methods are applied to the Ti-Tree Basin in central Australia to shed light on the importance of recharge from floodouts of ephemeral rivers in this arid environment. Ground water carbon-14 concentrations from boreholes are used to estimate the average recharge rate over the interval between where the ground water sample first entered the saturated zone and the bore. Environmental chloride concentrations in ground water samples provide estimates of the recharge rate at the exact point in the landscape where the sample entered the saturated zone. The results of the two tracer approaches indicate that recharge rates around one of the rivers and an extensive floodplain are generally higher than rates of diffuse recharge that occurs in areas of lower topographic relief. Ground water 2H/1H and 18O/16O compositions are all depleted in the heavier isotopes (delta2H = -67 per thousand to -50 per thousand; delta18O = -9.2 per thousand to -5.7%o) compared with the long-term, amount-weighted mean isotopic composition of rainfall in the area (delta2H = -33.8 per thousand; delta18O = -6.3 per thousand). This indicates that recharge throughout the basin occurs only after intense rainfall events of at least 150 to 200 mm/month. Finally, a recharge map is developed to highlight the spatial extent of the two recharge mechanisms. Floodout recharge to the freshest ground water (TDS <1,000 mg/L) is approximately 1.9 mm/year compared with a mean recharge rate of approximately 0.2 mm/year to the remainder of the basin. These findings have important implications for management of the ground water resource.

  1. Comparison of local- to regional-scale estimates of ground-water recharge in Minnesota, USA

    NASA Astrophysics Data System (ADS)

    Delin, Geoffrey N.; Healy, Richard W.; Lorenz, David L.; Nimmo, John R.

    2007-02-01

    SummaryRegional ground-water recharge estimates for Minnesota were compared to estimates made on the basis of four local- and basin-scale methods. Three local-scale methods (unsaturated-zone water balance, water-table fluctuations (WTF) using three approaches, and age dating of ground water) yielded point estimates of recharge that represent spatial scales from about 1 to about 1000 m 2. A fourth method (RORA, a basin-scale analysis of streamflow records using a recession-curve-displacement technique) yielded recharge estimates at a scale of 10-1000s of km 2. The RORA basin-scale recharge estimates were regionalized to estimate recharge for the entire State of Minnesota on the basis of a regional regression recharge (RRR) model that also incorporated soil and climate data. Recharge rates estimated by the RRR model compared favorably to the local and basin-scale recharge estimates. RRR estimates at study locations were about 41% less on average than the unsaturated-zone water-balance estimates, ranged from 44% greater to 12% less than estimates that were based on the three WTF approaches, were about 4% less than the age dating of ground-water estimates, and were about 5% greater than the RORA estimates. Of the methods used in this study, the WTF method is the simplest and easiest to apply. Recharge estimates made on the basis of the UZWB method were inconsistent with the results from the other methods. Recharge estimates using the RRR model could be a good source of input for regional ground-water flow models; RRR model results currently are being applied for this purpose in USGS studies elsewhere.

  2. Quantification of groundwater recharge in a hard rock terrain of Orissa: a case study.

    PubMed

    Sethi, Ranu Rani; Kumar, A; Sharma, S P

    2009-01-01

    A study was carried out to select the best method to estimate groundwater recharge in a hard rock terrain. Various standard empirical methods, soil-moisture balance method, water table fluctuation (WTF) method and commonly adopted norms set by Groundwater Estimation Committee (GEC), Govt of India were used to estimate recharge for the Munijhara watershed in the Nayagarh block of Orissa (India). The empirical formulae gave recharge rates ranging from 13 cm to 32 cm/year with average of 22.4 cm and standard deviation of 5.34, independent of other influencing factors like soil, topography and geology. The soil-moisture balance study indicated that recharge is more dependent on the continuous heavy rainfall total annual volume of rainfall. Recharge was limited at up to 10 mm per day, possibly due to presence of hard rock below the soil surface. The rise in water table depth was 3.45 m to 5.35 m with a mean rise of 4.5 m during the year 2006-2007. Annual groundwater recharge based on the WTF approach varied from 10.3 to 16.85 cm with a mean of 13.5 cm, standard deviation of 1.57 cm and coefficient of variation 11.57%. This recharge accounted for 8 to 14% of rainfall received. With a water budget approach based on GEC norms, recharge was calculated as 17 cm per year. The study showed that the magnitudes of annual groundwater recharge as estimated by the WST method and GEC norms are in conformity with other recent findings in India under the same climate conditions. Based on the results recharge structures could be planned in suitable locations to reduce fallow areas under the watershed. PMID:19717920

  3. DOM in recharge waters of the Santa Ana River Basin

    USGS Publications Warehouse

    Leenheer, J.A.; Aiken, G.R.; Woodside, G.; O'Connor-Patel, K.

    2007-01-01

    The urban Santa Ana River in California is the primary source of recharge water for Orange County's groundwater basin, which provides water to more than two million residents. This study was undertaken to determine the unidentified portion of dissolved organic matter (DOM) in various natural surface and reclaimed waters of the Santa Ana River Basin and to assess the potential health risk of this material. The most abundant organic contaminants were anionic detergent degradation products (constituting about 12% of the DOM), which have no known adverse health effects. In addition, high percentages of dissolved colloids from bacterial cell walls were found during storm flows; these colloids foul membranes used in water treatment. Although no significant health risks were ascribed to the newly characterized DOM, the authors note that even the small amounts of humic substances deposited during storm flow periods were responsible for significant increases in disinfection by_product formation potential in these waters.

  4. Using HDR (Hot Dry Rock) technology to recharge The Geysers

    SciTech Connect

    Brown, D.W.; Robinson, B.A.

    1990-01-01

    The main reason for the productivity decline at The Geysers geothermal field is obvious: more fluid is being withdrawn from the reservoir than is being returned by reinjection and natural recharge. However, there is another factor that may be contributing to this decline --- the method of reinjection. By reinjecting cold condensate directly into the steam dome as is the current practice, the very large pressure difference between the injected condensate and the underpressured reservoir guarantees that the reinjected fluid will fall rapidly to the bottom of the reservoir, with very little residence time for heat transfer. This point is very important since the vast majority of the heat contained in The Geysers geothermal field is stored in the hot rock comprising the reservoir. 10 refs., 4 figs.

  5. Resilient design of recharging station networks for electric transportation vehicles

    SciTech Connect

    Kris Villez; Akshya Gupta; Venkat Venkatasubramanian

    2011-08-01

    As societies shift to 'greener' means of transportation using electricity-driven vehicles one critical challenge we face is the creation of a robust and resilient infrastructure of recharging stations. A particular issue here is the optimal location of service stations. In this work, we consider the placement of battery replacing service station in a city network for which the normal traffic flow is known. For such known traffic flow, the service stations are placed such that the expected performance is maximized without changing the traffic flow. This is done for different scenarios in which roads, road junctions and service stations can fail with a given probability. To account for such failure probabilities, the previously developed facility interception model is extended. Results show that service station failures have a minimal impact on the performance following robust placement while road and road junction failures have larger impacts which are not mitigated easily by robust placement.

  6. Status of the development of rechargeable lithium cells

    NASA Technical Reports Server (NTRS)

    Halpert, G.; Surampudi, S.; Shen, D.; Huang, C-K.; Narayanan, S.; Vamos, E.; Perrone, D.

    1993-01-01

    The progress in the development of the ambient temperature lithium - titanium disulfide rechargeable cell under development at the Jet Propulsion Laboratory is described in this paper. Originally aimed at achieving a specific energy of 100 Wh/kg, 'AA' cells have demonstrated 125 Wh/kg at the C/3 discharge rate. The results of evaluating cell design parameters are discussed and cycling test data are also included in the paper. Safety tests results at various over-charge and over discharge conditions and rates proved to be uneventful. The test results of cell with built-in overcharge mechanism proved the concept was feasible. Replacing the lithium foil electrode with a Li(x)C resulted in a capacity at 1mA/cm(exp 2) of 200 mAh/gm and 235 mAh/gm at 0.167 mA.

  7. Identifying recharge from tropical cyclonic storms, Baja California Sur, Mexico.

    PubMed

    Eastoe, Christopher J; Hess, Greg; Mahieux, Susana

    2015-04-01

    Groundwater in the Todos Santos watershed in southern Baja California, and throughout the peninsula south of latitude 28°N, has values of (δ18 O‰, δD‰) ranging between (-8.3, -57) and (-10.9, -78). Such negative values are uncharacteristic of the site latitude near the sea level. Altitude effects do not explain the isotope data. Tropical depressions originating along the Pacific coast of North America yield rain with isotopic depletion; rain from these weather systems in southern Arizona commonly has δ18O values<-10‰ in comparison with amount-weighted mean summer and fall rain at -6‰. Isotope data indicate hurricane rain as the predominant source of recharge in southern Baja California, where named tropical depressions bring large rains (>50 mm) at least once every 2 to 3 years, and along the Pacific coast between Jalisco and Oaxaca.

  8. Using isotopes for design and monitoring of artificial recharge systems

    USGS Publications Warehouse

    Contributors: Hendriksson, N.; Kulongoski, J.T.; Massmann, G.; Newman, B.

    2013-01-01

    Over the past years, the IAEA has provided support to a number of Member States engaged in the implementation of hydrological projects dealing with the design and monitoring of artificial recharge ( A R ) systems, primarily situated in arid and semiarid regions. AR is defined as any engineered system designed to introduce water to, and store water in, underlying aquifers. Aquifer storage and recovery (ASR) is a specific type of AR used with the purpose of increasing groundwater resources. Different water management strategies have been tested under various geographical, hydrological and climatic regimes. However, the success of such schemes cannot easily be predicted, since many variables need to be taken into account in the early stages of every AR project.

  9. Conceptualisation of groundwater recharge from the Wairau River, New Zealand

    NASA Astrophysics Data System (ADS)

    Wilson, Scott; Wöhling, Thomas; Davidson, Peter

    2016-04-01

    The braided Wairau River is the main source of recharge to the Wairau gravel aquifer in Marlborough, New Zealand. Flow measurements indicate a 6 to 15 m3/s loss as the river traverses the Wairau alluvial fan, a distance of 15 km. The hydrological processes regulating this flow loss are not well understood. Theoretically, the relationship between a river and groundwater can be considered as being hydraulically connected (gaining or losing), disconnected, or transitional (Brunner et al. 2011). A disconnected river is distinguished from a hydraulically connected river by a partially saturated zone between the river bed and the aquifer. The aim of this study is to improve our conceptual understanding of how flow losses occur, and to test a new hypothesis that much of the river is hydraulic disconnected from the aquifer. It is practically difficult to make direct observations of the saturation status beneath a river bed. However, indirect observations can be employed to characterize the nature of the river-aquifer exchange, and we have used a variety of data sources (stratigraphy, piezometric surfaces including LiDAR, temperature and radon tracers). Several lines of evidence from these data sources indicate that the dominant recharge reach of the river is hydraulically disconnected, or at least transitional in nature. This simplifies the prediction of transient flow losses, which only requires knowledge of near-surface Kz and wetted river area values. The hydraulic mechanism for a disconnected river condition is the anisotropy of the sandy gravel sequence. The braided river depositional process has formed a finely layered sequence of silt, sand and gravel lenses. This stratification, combined with clast and particle imbrication, has formed a highly anisotropic hydrogeology. Results from aquifer tests analyzed for leakage have typical Kx values of 500 m/d and Kz values of around 0.5 m/d. The large Kx/Kz ratio enables the aquifer to potentially discharge more rapidly in a

  10. Layered cathode materials for lithium ion rechargeable batteries

    DOEpatents

    Kang, Sun-Ho; Amine, Khalil

    2007-04-17

    A number of materials with the composition Li.sub.1+xNi.sub..alpha.Mn.sub..beta.Co.sub..gamma.M'.sub..delta.O.sub.2-- zF.sub.z (M'=Mg,Zn,Al,Ga,B,Zr,Ti) for use with rechargeable batteries, wherein x is between about 0 and 0.3, .alpha. is between about 0.2 and 0.6, .beta. is between about 0.2 and 0.6, .gamma. is between about 0 and 0.3, .delta. is between about 0 and 0.15, and z is between about 0 and 0.2. Adding the above metal and fluorine dopants affects capacity, impedance, and stability of the layered oxide structure during electrochemical cycling.

  11. Rechargeable cells with modified MnO2 cathodes

    NASA Astrophysics Data System (ADS)

    Dzieciuch, M. A.; Gupta, N.; Wroblowa, H. S.

    1988-10-01

    The recent invention of rechargeable 'modified' manganese oxide materials paves the way to the development of secondary batteries suitable for numerous applications. This includes alternatives to primary dry cells, and secondary lead/acid and nickel-cadmium batteries. Present results describe the performance of cells in which the modified materials are coupled with zinc and iron. As opposed to iron which does not affect the longevity and capacity retention of the modified electrodes, zinc has a pejorative effect on modified MnO2 materials, owing to the formation of heterolite at the positive electrode. Methods to alleviate this effect and produce viable modified MnO2/Zn systems are described. At present, these systems retain about 50 percent of their theoretical one-electron capacity even after two hundred fast charge-discharge cycles.

  12. Etude des Abondances de MG et de fe dans la Composante Stellaire des Disques des Galaxies Spirales

    NASA Astrophysics Data System (ADS)

    Beauchamp, Dominique

    Je presente ici une technique d'observation par imagerie des disques stellaires des galaxies spirales. Je tente, a l'aide d'un modele evolutif multiphase, de determiner les abondances de fer et de magnesium dans les disques. Dans ce but, je mesure les indices Mg2 et Fe5270 du systeme de Lick. Ces elements representent un choix judicieux d'indicateurs car ils sont formes par des supernovae de deux types differents ayant des durees de vie differentes. Le rapport d'abondances de ces deux elements est un indicateur du taux de formation des populations stellaires. Je decris, en premier lieu, les observations, la technique de mesure, ainsi que son application. J'analyse ensuite les indices mesures. A partir du modele multiphase, j'explore differents parametres physiques des spirales comme le taux de formation stellaire, l'evolution des abondances, les effets possibles de la presence de la barre, etc.

  13. Analysis of subsurface temperature data to quantify groundwater recharge rates in a closed Altiplano basin, northern Chile

    NASA Astrophysics Data System (ADS)

    Kikuchi, C. P.; Ferré, T. P. A.

    2016-09-01

    Quantifying groundwater recharge is a fundamental part of groundwater resource assessment and management, and is requisite to determining the safe yield of an aquifer. Natural groundwater recharge in arid and semi-arid regions comprises several mechanisms: in-place, mountain-front, and mountain-block recharge. A field study was undertaken in a high-plain basin in the Altiplano region of northern Chile to quantify the magnitude of in-place and mountain-front recharge. Water fluxes corresponding to both recharge mechanisms were calculated using heat as a natural tracer. To quantify in-place recharge, time-series temperature data in cased boreholes were collected, and the annual fluctuation at multiple depths analyzed to infer the water flux through the unsaturated zone. To quantify mountain-front recharge, time-series temperature data were collected in perennial and ephemeral stream channels. Streambed thermographs were analyzed to determine the onset and duration of flow in ephemeral channels, and the vertical water fluxes into both perennial and ephemeral channels. The point flux estimates in streambeds and the unsaturated zone were upscaled to channel and basin-floor areas to provide comparative estimates of the range of volumetric recharge rates corresponding to each recharge mechanism. The results of this study show that mountain-front recharge is substantially more important than in-place recharge in this basin. The results further demonstrate the worth of time-series subsurface temperature data to characterize both in-place and mountain-front recharge processes.

  14. Moisture content and recharge estimates at the Yakima Barricade borehole

    SciTech Connect

    Murphy, E.M.; Szescody, J.E.; Phillips, S.J.

    1991-12-01

    The DOE Deep Microbiology Program recently drilled a borehole near the Yakima Barricade, west of the 200 Areas. The area is vegetated by mature sagebrush. The borehole was drilled by cable tool and approximately every 1.5 m, sediment samples were collected in a bucket by the drill site geologist. Sediment samples for moisture content were sealed quickly Samples of opportunity'' were collected for the HSPA program (Hanford Site Performance Assessment), Isotope Recharge task. It should be noted that, although many QA Level II procedures were incorporated into the dulling and sampling, the Deep Microbiology Program is officially designated QA Level III, and therefore, the recharge values that we report here should only be usedfor planning purposes. A series of graphs illustrate the moisture content and chloride profiles in the Hanford Forrmtion at the Yakima Barricade Borehole. The gravimetric moisture content generally ranges between 0.01 and 0.08 in the first 70 m of sediment (only the first 30 m are shown in the figure), values that are typically found at the Hanford Site. The stratigraphy of this borehole is also attached. The first 1.5 m of the soil profile is Warden silt loam (designated eolian), followed by over 50 m of Hanford Formation. The Hanford Formation is composed of unconsolidated sands, silts, and gravels that were carried into the area by glacial flood waters during the close of the last Ice Age. Below the Hanford Formation is the Ringold Formation composed of semiconsolidated sediments. The water table is located at a depth of approximately 100 m.

  15. Moisture content and recharge estimates at the Yakima Barricade borehole

    SciTech Connect

    Murphy, E.M.; Szescody, J.E.; Phillips, S.J.

    1991-12-01

    The DOE Deep Microbiology Program recently drilled a borehole near the Yakima Barricade, west of the 200 Areas. The area is vegetated by mature sagebrush. The borehole was drilled by cable tool and approximately every 1.5 m, sediment samples were collected in a bucket by the drill site geologist. Sediment samples for moisture content were sealed quickly ``Samples of opportunity`` were collected for the HSPA program (Hanford Site Performance Assessment), Isotope Recharge task. It should be noted that, although many QA Level II procedures were incorporated into the dulling and sampling, the Deep Microbiology Program is officially designated QA Level III, and therefore, the recharge values that we report here should only be usedfor planning purposes. A series of graphs illustrate the moisture content and chloride profiles in the Hanford Forrmtion at the Yakima Barricade Borehole. The gravimetric moisture content generally ranges between 0.01 and 0.08 in the first 70 m of sediment (only the first 30 m are shown in the figure), values that are typically found at the Hanford Site. The stratigraphy of this borehole is also attached. The first 1.5 m of the soil profile is Warden silt loam (designated eolian), followed by over 50 m of Hanford Formation. The Hanford Formation is composed of unconsolidated sands, silts, and gravels that were carried into the area by glacial flood waters during the close of the last Ice Age. Below the Hanford Formation is the Ringold Formation composed of semiconsolidated sediments. The water table is located at a depth of approximately 100 m.

  16. Bubble plumes generated during recharge of basaltic magma reservoirs

    NASA Astrophysics Data System (ADS)

    Phillips, Jeremy C.; Woods, Andrew W.

    2001-03-01

    CO 2 is relatively insoluble in basaltic magma at low crustal pressures. It therefore exists as a gas phase in the form of bubbles in shallow crustal reservoirs. Over time these bubbles may separate gravitationally from the magma in the chamber. As a result, any new magma which recharges the chamber from deeper in the crust may be more bubble-rich and hence of lower density than the magma in the chamber. Using scaling arguments, we show that for typical recharge fluxes, such a source of low-viscosity, bubble-rich basalt may generate a turbulent bubble plume within the chamber. We also show that the bubbles are typically sufficiently small to have a low Reynolds number and to remain in the flow. We then present a series of analogue laboratory experiments which identify that the motion of such a turbulent bubble-driven line plume is well described by the classical theory of buoyant plumes. Using the classical plume theory we then examine the effect of the return flow associated with such bubble plumes on the mixing and redistribution of bubbles within the chamber. Using this model, we show that a relatively deep bubbly layer of magma may form below a thin foam layer at the roof. If, as an eruption proceeds, there is a continuing influx at the base of the chamber, then our model suggests that the bubble content of the bubbly layer may gradually increase. This may lead to a transition from lava flow activity to more explosive fire-fountaining activity. The foam layer at the top of the chamber may provide a flux for the continual outgassing from the flanks of the volcano [Ryan, Am. Geophys. Union Geophys. Monogr. 91 (1990)] and if it deepens sufficiently it may contribute to the eruptive activity [Vergniolle and Jaupart, J. Geophys. Res. 95 (1990) 2793-3001].

  17. The chemistry and status of rechargeable molten-salt batteries

    SciTech Connect

    Cairns, E.J.; Mamantov, G.; Tischer, R.P.; Vissers, D.R.

    1983-05-01

    The chemistry and the state of development of rechargeable molten salt cells and batteries of current interest are reviewed in this work. Molten-salt cells offer the most attractive combination of high specific energy (100-200 Wh/kg), high specific power (50-200 W/kg), and long cycle life (300-1500 cycles) of any rechargeable cells under investigation at this time. It is these important features that justify the development and application of cells that have the disadvantages of operation at elevated temperatures, and difficult materials problems. There are two major categories of molten-salt cells: those in which the molten salt is the sole electrolyte, and those in which the molten salt serves as a reactant and as an auxiliary electrolyte (the main electrolyte is a solid). In the first category are such cells as LiAl/LiCl-KCl/FeS, LiAl/LiCl-KCl/FeS/sub 2/, and Li/sub 4/Si/LiCl-KCl/FeS/sub 2/; in the second category are Na/Na/sub 2/O . xAl/sub 2/O/sub 3//Na/sub 2/S /SUB n/ -S, Na/Na/sup +/ glass/Na/sub 2/S /SUB n/ -S, Na/Na/sub 2/O . xAl/sub 2/O/sub 3//SCl/sub 3/AlCl/sub 4/ in NaCl-AlCl/sub 3/, and Li/Li/sub 2/O/LiNO/sub 3/-KNO/sub 3//V/sub 2/O/sub 5/. These cells have operating temperatures ranging from 150 to 475/sup 0/C, and all must be sealed from the atmosphere because of the alkali metal reactants and hydrolytic degradation of molten salt electrolytes.

  18. Fiber Optic Distributed Temperature Sensing of Recharge Basin Percolation Dynamics

    NASA Astrophysics Data System (ADS)

    Becker, M.; Allen, E. M.; Hutchinson, A.

    2014-12-01

    Infiltration (spreading) basins are a central component of managed aquifer and recovery operations around the world. The concept is simple. Water is percolated into an aquifer where it can be withdrawn at a later date. However, managing infiltration basins can be complicated by entrapped air in sediments, strata of low permeability, clogging of the recharge surface, and biological growth, among other factors. Understanding the dynamics of percolation in light of these complicating factors provides a basis for making management decisions that increase recharge efficiency. As an aid to understanding percolation dynamics, fiber optic distribute temperature sensing (DTS) was used to track heat as a tracer of water movement in an infiltration basin. The diurnal variation of temperature in the basin was sensed at depth. The time lag between the oscillating temperature signal at the surface and at depth indicated the velocity of water percolation. DTS fiber optic cables were installed horizontally along the basin and vertically in boreholes to measure percolation behavior. The horizontal cable was installed in trenches at 0.3 and 1 m depth, and the vertical cable was installed using direct push technology. The vertical cable was tightly wound to produce a factor of 10 increase in spatial resolution of temperature measurements. Temperature was thus measured every meter across the basin and every 10 cm to a depth of 10 m. Data from the trenched cable suggested homogeneous percolation across the basin, but infiltration rates were a function of stage indicating non-ideal percolation. Vertical temperature monitoring showed significant lateral flow in sediments underlying the basin both during saturation and operation of the basin. Deflections in the vertical temperature profile corresponded with fine grained layers identified in core samples indicating a transient perched water table condition. The three-dimensional flow in this relatively homogenous surficial geology calls

  19. Response to recharge variation of thin rainwater lenses and their mixing zone with underlying saline groundwater

    NASA Astrophysics Data System (ADS)

    Eeman, S.; van der Zee, S. E. A. T. M.; Leijnse, A.; de Louw, P. G. B.; Maas, C.

    2012-10-01

    In coastal zones with saline groundwater, fresh groundwater lenses may form due to infiltration of rain water. The thickness of both the lens and the mixing zone, determines fresh water availability for plant growth. Due to recharge variation, the thickness of the lens and the mixing zone are not constant, which may adversely affect agricultural and natural vegetation if saline water reaches the root zone during the growing season. In this paper, we study the response of thin lenses and their mixing zone to variation of recharge. The recharge is varied using sinusoids with a range of amplitudes and frequencies. We vary lens characteristics by varying the Rayleigh number and Mass flux ratio of saline and fresh water, as these dominantly influence the thickness of thin lenses and their mixing zone. Numerical results show a linear relation between the normalised lens volume and the main lens and recharge characteristics, enabling an empirical approximation of the variation of lens thickness. Increase of the recharge amplitude causes increase and the increase of recharge frequency causes a decrease in the variation of lens thickness. The average lens thickness is not significantly influenced by these variations in recharge, contrary to the mixing zone thickness. The mixing zone thickness is compared to that of a Fickian mixing regime. A simple relation between the travelled distance of the centre of the mixing zone position due to variations in recharge and the mixing zone thickness is shown to be valid for both a sinusoidal recharge variation and actual records of daily recharge data. Starting from a step response function, convolution can be used to determine the effect of variable recharge in time. For a sinusoidal curve, we can determine delay of lens movement compared to the recharge curve as well as the lens amplitude, derived from the convolution integral. Together the proposed equations provide us with a first order approximation of lens characteristics using

  20. Response to recharge variation of thin lenses and their mixing zone with underlying saline groundwater

    NASA Astrophysics Data System (ADS)

    Eeman, S.; van der Zee, S. E. A. T. M.; Leijnse, A.; de Louw, P. G. B.; Maas, C.

    2012-01-01

    In coastal zones with saline groundwater, fresh groundwater lenses may form due to infiltration of rain water. The thickness of both the lens and the mixing zone, determines fresh water availability for plant growth. Due to recharge variation, the thickness of the lens and the mixing zone are not constant, which may adversely affect agricultural and natural vegetation if saline water reaches the root zone during the growing season. In this paper, we study the response of thin lenses and their mixing zone to variation of recharge. The recharge is varied using sinusoids with a range of amplitudes and frequencies. We vary lens characteristics by varying the Rayleigh number and Mass flux ratio of saline and fresh water, as these dominantly influence the thickness of thin lenses and their mixing zone. Numerical results show a linear relation between the normalized lens volume and the main lens and recharge characteristics, enabling an analytical approximation of the variation of lens thickness. Increase of the recharge amplitude causes increase, and increase of recharge frequency causes decrease in the variation of lens thickness. The average lens thickness is not significantly influenced by these variations in recharge, contrary to the mixing zone thickness. The mixing zone thickness is compared to that of a Fickian mixing regime. A simple relation between the travelled distance of the center of the mixing zone position due to variations in recharge and the mixing zone thickness is shown to be valid for both a sinusoidal recharge variation and actual records of daily recharge data. Starting from a step response function, convolution can be used to determine the effect of variable recharge in time. For a sinusoidal curve, we can determine delay of lens movement compared to the recharge curve as well as the lens amplitude, derived from the convolution integral. Together the proposed equations provide us with a first order approximation of lens characteristics using basic

  1. Classification of 20 DES Supernova with OzDES

    NASA Astrophysics Data System (ADS)

    Davis, T. M.; Kim, A. G.; Macualay, E.; Lidman, C.; Sharp, R.; Tucker, B. E.; Yuan, F.; Zhang, B.; Lewis, G. F.; Sommer, N. E.; Martini, P.; Mould, J.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.

    2015-12-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  2. Classification of 8 DES Supernova with OzDES

    NASA Astrophysics Data System (ADS)

    King, A.; Moller, A.; Sommer, N. E.; Tucker, B. E.; Childress, M. J.; Lewis, G. F.; Lidman, C.; OâNeill, C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; D'Andrea, C.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.

    2016-09-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  3. Classification of 13 DES supernova with OzDES

    NASA Astrophysics Data System (ADS)

    Sommer, N.; Tucker, B. E.; Moller, A.; Zhang, B.; Macualay, E.; Lidman, C.; Gshwend, J.; Martini, P.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.

    2016-09-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  4. Classification of 3 DES Supernovae with OzDES

    NASA Astrophysics Data System (ADS)

    Moller, A.; Tucker, B. E.; Yuan, F.; Lewis, G.; Lidman, C.; Macaulay, E.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.

    2016-02-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  5. Classification of 2 DES supernova with OzDES

    NASA Astrophysics Data System (ADS)

    O'Neill, C. R.; Moller, A.; Sommer, N. E.; Tucker, B. E.; Childress, M. J.; Lewis, G. F.; Lidman, C.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; D'Andrea, C.; Gladney, L.; March, M.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Macaulay, E.; Nichol, R.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Gupta, R.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Papadopoulos, A.; Morganson, E.

    2016-10-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  6. Iron-Air Rechargeable Battery: A Robust and Inexpensive Iron-Air Rechargeable Battery for Grid-Scale Energy Storage

    SciTech Connect

    2010-10-01

    GRIDS Project: USC is developing an iron-air rechargeable battery for large-scale energy storage that could help integrate renewable energy sources into the electric grid. Iron-air batteries have the potential to store large amounts of energy at low cost—iron is inexpensive and abundant, while oxygen is freely obtained from the air we breathe. However, current iron-air battery technologies have suffered from low efficiency and short life spans. USC is working to dramatically increase the efficiency of the battery by placing chemical additives on the battery’s iron-based electrode and restructuring the catalysts at the molecular level on the battery’s air-based electrode. This can help the battery resist degradation and increase life span. The goal of the project is to develop a prototype iron-air battery at significantly cost lower than today’s best commercial batteries.

  7. Managed aquifer recharge with low impact development under a changing climate (Invited)

    NASA Astrophysics Data System (ADS)

    Gurdak, J. J.; Newcomer, M. E.; Sklar, L. S.; Nanus, L.

    2013-12-01

    Groundwater resources in urban environments are highly vulnerable to human pressures and climate variability and change, and many communities face water shortages and need to find alternative water supplies. Therefore, understanding how low impact development (LID) planning and best management practices (BMPs) affect recharge rates and volumes is important because of the increasing use of LID and BMPs to reduce stormwater runoff and improve surface-water quality. Some BMPs may also enhance recharge, which has often been considered a secondary management benefit. Enhancing the capacity for managed aquifer recharge with stormwater beneath LID is an important step toward the sustainable and conjunctive use of surface and groundwater resources in urban environments. This field and modeling study quantifies urban recharge rates, volumes, and efficiency beneath a BMP infiltration trench and irrigated lawn considering historical El Niño/Southern Oscillation (ENSO) variability and future climate change using simulated precipitation from the Geophysical Fluid Dynamic Laboratory (GFDL) A1F1 climate scenario. Using results from a suite of methods to measure and model recharge beneath a recently installed (2009) BMP infiltration trench, this study addresses three main questions: (1) What are the benefits of measuring recharge using in-situ methods compared to model-based and other simple estimates of recharge beneath a LID BMP? (2) What are recharge rates and volumes beneath the infiltration trench, how do they compare to an irrigated lawn that represents a non-LID source of urban recharge, and what are the important factors controlling recharge beneath the two sites? (3) How effective is the LID BMP in capturing and recharging urban stormwater considering historical ENSO variability and future climate change? We find that in-situ and modeling methods are complementary, particularly for simulating historical and future recharge scenarios, and the in-situ data are critical for

  8. Vertical carbon-14 profiles for resolving spatial variability in recharge in arid environments

    NASA Astrophysics Data System (ADS)

    Wood, Cameron; Cook, Peter G.; Harrington, Glenn A.

    2015-01-01

    Groundwater age tracers are often measured to help constrain estimates of groundwater recharge, especially in arid environments where other methods are unsuitable. However multiple processes can influence the shape of vertical tracer profiles in an aquifer including (1) variation in tracer input concentrations from the unsaturated zone, (2) the role of diffusion in transporting tracer into the aquifer when fluxes are low and (3) spatial variability in recharge. This study demonstrates the influence of spatially variable recharge and spatially variable carbon-14 (14C) activities in the unsaturated zone on vertical 14C profiles in groundwater. Through groundwater flow and solute transport modelling, we demonstrate that recharge estimated from single point measurements of 14C may be wrong more than an order of magnitude when unsaturated zone 14C activities and recharge vary spatially. We then present a case study from the Ti Tree Basin in arid central Australia, where detailed profiles of 14C activity in unsaturated zone gas and groundwater have been measured, and spatial variability in unsaturated zone 14C is observed (ranging from 54 to 106 pMC above the watertable). Through modelling our data, we show that when unsaturated zone 14C activities are known, measurement of the 14C profile can help constrain estimates of recharge and its spatial variability. This approach improves our understanding of groundwater flow in the Ti Tree Basin, by showing mountain front recharge to be an important mechanism.

  9. A simulation model to assess groundwater recharge over Europe's karst regions

    NASA Astrophysics Data System (ADS)

    Hartmann, A.; Gleeson, T.; Rosolem, R.; Pianosi, F.; Wada, Y.; Wagener, T.

    2014-11-01

    Karst develops through the dissolution of carbonate rock and is a major source of groundwater contributing up to half of the total drinking water supply in some European countries. Previous approaches to model future water availability in Europe are either too-small scale or do not incorporate karst processes, i.e. preferential flow paths. This study presents the first simulations of groundwater recharge in all karst regions in Europe with a parsimonious karst hydrology model. A novel parameter confinement strategy combines a priori information with recharge-related observations (actual evapotranspiration and soil moisture) at locations across Europe while explicitly identifying uncertainty in the model parameters. Europe's karst regions are divided into 4 typical karst landscapes (humid, mountain, Mediterranean and desert) by cluster analysis and recharge is simulated from 2002 to 2012 for each karst landscape. Mean annual recharge ranges from negligible in deserts to > 1 m a-1 in humid regions. The majority of recharge rates ranges from 20-50% of precipitation and are sensitive to sub-annual climate variability. Simulation results are consistent with independent observations of mean annual recharge and significantly better than other global hydrology models that do not consider karst processes (PCR-GLOBWB, WaterGAP). Global hydrology models systematically underestimate karst recharge implying that they over-estimate actual evapotranspiration and surface runoff. Karst water budgets and thus information to support management decisions regarding drinking water supply and flood risk are significantly improved by our model.

  10. A large-scale simulation model to assess karstic groundwater recharge over Europe and the Mediterranean

    NASA Astrophysics Data System (ADS)

    Hartmann, A.; Gleeson, T.; Rosolem, R.; Pianosi, F.; Wada, Y.; Wagener, T.

    2015-06-01

    Karst develops through the dissolution of carbonate rock and is a major source of groundwater contributing up to half of the total drinking water supply in some European countries. Previous approaches to model future water availability in Europe are either too-small scale or do not incorporate karst processes, i.e. preferential flow paths. This study presents the first simulations of groundwater recharge in all karst regions in Europe with a parsimonious karst hydrology model. A novel parameter confinement strategy combines a priori information with recharge-related observations (actual evapotranspiration and soil moisture) at locations across Europe while explicitly identifying uncertainty in the model parameters. Europe's karst regions are divided into four typical karst landscapes (humid, mountain, Mediterranean and desert) by cluster analysis and recharge is simulated from 2002 to 2012 for each karst landscape. Mean annual recharge ranges from negligible in deserts to > 1 m a-1 in humid regions. The majority of recharge rates range from 20 to 50% of precipitation and are sensitive to subannual climate variability. Simulation results are consistent with independent observations of mean annual recharge and significantly better than other global hydrology models that do not consider karst processes (PCR-GLOBWB, WaterGAP). Global hydrology models systematically under-estimate karst recharge implying that they over-estimate actual evapotranspiration and surface runoff. Karst water budgets and thus information to support management decisions regarding drinking water supply and flood risk are significantly improved by our model.

  11. An innovative artificial recharge system to enhance groundwater storage in basaltic terrain: example from Maharashtra, India

    NASA Astrophysics Data System (ADS)

    Bhusari, Vijay; Katpatal, Y. B.; Kundal, Pradeep

    2016-08-01

    The management of groundwater poses challenges in basaltic terrain as its availability is not uniform due to the absence of primary porosity. Indiscriminate excessive withdrawal from shallow as well as deep aquifers for meeting increased demand can be higher than natural recharge, causing imbalance in demand and supply and leading to a scarcity condition. An innovative artificial recharge system has been conceived and implemented to augment the groundwater sources at the villages of Saoli and Sastabad in Wardha district of Maharashtra, India. The scheme involves resectioning of a stream bed to achieve a reverse gradient, building a subsurface dam to arrest subsurface flow, and installation of recharge shafts to recharge the deeper aquifers. The paper focuses on analysis of hydrogeological parameters like porosity, specific yield and transmissivity, and on temporal groundwater status. Results indicate that after the construction of the artificial recharge system, a rise of 0.8-2.8 m was recorded in the pre- and post-monsoon groundwater levels in 12 dug wells in the study area; an increase in the yield was also noticed which solved the drinking water and irrigation problems. Spatial analysis was performed using a geographic information system to demarcate the area of influence of the recharge system due to increase in yields of the wells. The study demonstrates efficacy, technical viability and applicability of an innovative artificial recharge system constructed in an area of basaltic terrain prone to water scarcity.

  12. Multiple-methods investigation of recharge at a humid-region fractured rock site, Pennsylvania, USA

    USGS Publications Warehouse

    Heppner, C.S.; Nimmo, J.R.; Folmar, G.J.; Gburek, W.J.; Risser, D.W.

    2007-01-01

    Lysimeter-percolate and well-hydrograph analyses were combined to evaluate recharge for the Masser Recharge Site (central Pennsylvania, USA). In humid regions, aquifer recharge through an unconfined low-porosity fractured-rock aquifer can cause large magnitude water-table fluctuations over short time scales. The unsaturated hydraulic characteristics of the subsurface porous media control the magnitude and timing of these fluctuations. Data from multiple sets of lysimeters at the site show a highly seasonal pattern of percolate and exhibit variability due to both installation factors and hydraulic property heterogeneity. Individual event analysis of well hydrograph data reveals the primary influences on water-table response, namely rainfall depth, rainfall intensity, and initial water-table depth. Spatial and seasonal variability in well response is also evident. A new approach for calculating recharge from continuous water-table elevation records using a master recession curve (MRC) is demonstrated. The recharge estimated by the MRC approach when assuming a constant specific yield is seasonal to a lesser degree than the recharge estimate resulting from the lysimeter analysis. Partial reconciliation of the two recharge estimates is achieved by considering a conceptual model of flow processes in the highly-heterogeneous underlying fractured porous medium. ?? Springer-Verlag 2007.

  13. Mechanisms of subglacial groundwater recharge as derived from noble gas, 14C, and stable isotopic data

    NASA Astrophysics Data System (ADS)

    Grundl, Tim; Magnusson, Nathan; Brennwald, Matthias S.; Kipfer, Rolf

    2013-05-01

    Noble gas, stable isotope and 14C data from samples collected along groundwater flow path within a confined Paleozoic aquifer in northeastern Wisconsin, USA are used to deduce the effect of the Laurentide Ice Sheet (LIS) on the underlying groundwater and its recharge dynamics. During the last glacial maximum the investigated area was near the center of the Green Bay Lobe of the LIS. 14C ages that extend to 26 k.a. and low δ18O derived temperatures during the time that the LIS was present indicate that aquifer recharge continued when ice covered the area. δ18O values as low as -17.5‰ and δ2H values as low as -127.7‰ indicate that a significant portion of aquifer recharge was derived from glacial meltwater that maintained its glacial isotopic signature during melting and subsequent recharge. Noble gas temperatures that remain above freezing at a constant ~3 °C, unusually high excess air (ΔNe) values and noble gas fractionation patterns indicate that recharge occurred across a very dynamic water table located within the ice sheet. This englacial hydrologic system experienced recharge heads of as much as 7.8 m. Evidence for direct recharge of basal meltwater into the aquifer is not seen. To the authors' knowledge this is the first time that noble gas and isotope tracers have been used to deduce the provenance of aquifer water beneath continental ice sheets.

  14. Estimating recharge thresholds in tropical karst island aquifers: Barbados, Puerto Rico and Guam

    NASA Astrophysics Data System (ADS)

    Jones, Ian C.; Banner, Jay L.

    2003-07-01

    The hydrology and geochemistry of groundwater in tropical island aquifers, such as Barbados, Guam and Puerto Rico, are significantly influenced by tropical climatic conditions. Recharge to these aquifers is the product of regional and local climate patterns that control rainfall. Oxygen isotopes can be used to estimate the amount and timing of recharge on these islands because seasonal fluctuations of rainwater oxygen isotopic compositions are related to the amount of rainfall. The karst aquifers on Barbados, Guam and Puerto Rico have similar rainwater and groundwater oxygen isotopic compositions. Comparison of groundwater and rainwater oxygen isotopic compositions in the three aquifers indicates that: (1) recharge occurs by rapid infiltration with little evaporation prior to recharge; and (2) recharge is associated with similar monthly rainfall thresholds of 190-200 mm. These rainfall thresholds are remarkably similar for three aquifers in different geographic locations. Differences between the spatial variations of groundwater oxygen isotopic compositions on Barbados and Puerto Rico can be attributed to the more complex groundwater flow system on Puerto Rico. The surprising similarities of hydrologic conditions under which recharge will take place can be attributed to similarities in climate and geologic conditions, such as soils and limestone bedrock, that exist on the three islands. We therefore speculate that similar recharge-rainfall thresholds may be observed in other tropical karst aquifers.

  15. A digital procedure for ground water recharge and discharge pattern recognition and rate estimation.

    PubMed

    Lin, Yu-Feng; Anderson, Mary P

    2003-01-01

    A digital procedure to estimate recharge/discharge rates that requires relatively short preparation time and uses readily available data was applied to a setting in central Wisconsin. The method requires only measurements of the water table, fluxes such as stream baseflows, bottom of the system, and hydraulic conductivity to delineate approximate recharge/discharge zones and to estimate rates. The method uses interpolation of the water table surface, recharge/discharge mapping, pattern recognition, and a parameter estimation model. The surface interpolator used is based on the theory of radial basis functions with thin-plate splines. The recharge/discharge mapping is based on a mass-balance calculation performed using MODFLOW. The results of the recharge/discharge mapping are critically dependent on the accuracy of the water table interpolation and the accuracy and number of water table measurements. The recharge pattern recognition is performed with the help of a graphical user interface (GUI) program based on several algorithms used in image processing. Pattern recognition is needed to identify the recharge/discharge zonations and zone the results of the mapping method. The parameter estimation program UCODE calculates the parameter values that provide a best fit between simulated heads and flows and calibration head-and-flow targets. A model of the Buena Vista Ground Water Basin in the Central Sand Plains of Wisconsin is used to demonstrate the procedure.

  16. Vadose zone-attenuated artificial recharge for input to a ground water model.

    PubMed

    Nichols, William E; Wurstner, Signe K; Eslinger, Paul W

    2007-01-01

    Accurate representation of artificial recharge is requisite to calibration of a ground water model of an unconfined aquifer for a semiarid or arid site with a vadose zone that imparts significant attenuation of liquid transmission and substantial anthropogenic liquid discharges. Under such circumstances, artificial recharge occurs in response to liquid disposal to the vadose zone in areas that are small relative to the ground water model domain. Natural recharge, in contrast, is spatially variable and occurs over the entire upper boundary of a typical unconfined ground water model. An improved technique for partitioning artificial recharge from simulated total recharge for inclusion in a ground water model is presented. The improved technique is applied using data from the semiarid Hanford Site. From 1944 until the late 1980s, when Hanford's mission was the production of nuclear materials, the quantities of liquid discharged from production facilities to the ground vastly exceeded natural recharge. Nearly all hydraulic head data available for use in calibrating a ground water model at this site were collected during this period or later, when the aquifer was under the diminishing influence of the massive water disposals. The vadose zone is typically 80 to 90 m thick at the Central Plateau where most production facilities were located at this semiarid site, and its attenuation of liquid transmission to the aquifer can be significant. The new technique is shown to improve the representation of artificial recharge and thereby contribute to improvement in the calibration of a site-wide ground water model.

  17. Impact of artificial recharge on dissolved noble gases in groundwater in California.

    PubMed

    Cey, Bradley D; Hudson, G Bryant; Moran, Jean E; Scanlon, Bridget R

    2008-02-15

    Dissolved noble gas concentrations in groundwater can provide valuable information on recharge temperatures and enable 3H-3He age-dating with the use of physically based interpretive models. This study presents a large (905 samples) data set of dissolved noble gas concentrations from drinking water supply wells throughout California, representing a range of physiographic, climatic, and water management conditions. Three common interpretive models (unfractionated air, UA; partial re-equilibration, PR; and closed system equilibrium, CE) produce systematically different recharge temperatures or ages; however, the ability of the different models to fit measured data within measurement uncertainty indicates that goodness-of-fit is not a robust indicator for model appropriateness. Therefore caution is necessary when interpreting model results. Samples from multiple locations contained significantly higher Ne and excess air concentrations than reported in the literature, with maximum excess air tending toward 0.05 cm3 STP g(-1) (deltaNe approximately 400%). Artificial recharge is the most plausible cause of the high excess air concentrations. The ability of artificial recharge to dissolve greater amounts of atmospheric gases has important implications for oxidation-reduction dependent chemical reactions. Measured gas concentration ratios suggest that diffusive degassing may have occurred. Understanding the physical processes controlling gas dissolution during groundwater recharge is critical for optimal management of artificial recharge and for predicting changes in water quality that can occur following artificial recharge.

  18. Artificial recharge experiments on the Ship Creek alluvial fan, Anchorage, Alaska

    USGS Publications Warehouse

    Anderson, Gary S.

    1977-01-01

    During the summers of 1973 and 174, water from Ship Creek, Alaska, was diverted at an average rate of approximately 6 cfs (cubic feet per second) to an 11-acre recharge basin. Maximum sustained unit recharge for the basin was approximately 1.4 feet per day. During 1975 a second basin of 8 acres was also used for recharge, and the total diversion rate was increased to as much as 30 cfs. The second basin was never completely filled, but the unit recharge rate was at least four times as great as that in the first basin. During 1973 and 1974, when only one recharge basin was in operation, a maximum rise of 18 feet was observed in the ground-water table near the basin. In 1975, when both basins were being used, the maximum rise was 30 feet in the same area. During 1973 and 1974, the water-level rise was 12 and 8 feet in the unconfined and confined systems, respectively, at a point 4,400 feet downgradient from the basins; in 1975 the rise at the same point was 31 and 16 feet, respectively. The potentiometric rise that was achieved in the confined aquifer during summer operation of the recharge basins was quickly dissipated when diversion stopped and the basins drained. Thus the benefits of recharge would not persist into late winter, the critical period for water availability in Anchorage, unless diversion to the basins could be continued until January or February. (Woodard-USGS)

  19. Responses of groundwater recharge to land-cover changes and climate variability

    NASA Astrophysics Data System (ADS)

    Guan, Huade; Xu, Xiang; Ding, Zhenyu; Deng, Zijuan; Simmons, Craig; Hutson, John; Love, Andy; Ajami, Hoori

    2014-05-01

    It is estimated that groundwater directly provides drinking water for 1.5 billion people in the world. Anthropogenic activities during the past 200 years have led to the conversion of large areas of natural forest and grassland to cropland and pasture. Understanding and quantification of changes in groundwater recharge after surface vegetation alteration are important not only for water resource management, but also for land-use and land-cover management. On the other hand, groundwater recharge also responds to climate variability and changes. In this paper, we discuss two groundwater recharge estimation methods of different temporal resolution: chloride mass balance (CMB), and storage-discharge relationship (S-Q). Application of the CMB method over areas of historical forest clearance, or recent plantation, suffers from two difficulties: pre-clearance (or pre-plantation) recharge may have been contaminated by recharge that occurred after forest clearance (or plantation); and the post-clearance (or post-plantation) recharge may not yet have reached new chloride equilibrium. In coastal areas, strong spatial variability in chloride deposition leads to an additional difficulty in appropriately applying the CMB method. This presentation will discuss some recent development to address these difficulties. Meanwhile, an improved conceptual framework of the S-Q method for estimating seasonal and inter-annual variability of groundwater recharge is presented as well. Both are shown with case studies based at the Mount Lofty Ranges of South Australia.

  20. Enhanced recharge rates and a greater sensitivity to climate variations in regions with heterogeneous subsurface

    NASA Astrophysics Data System (ADS)

    Hartmann, A. J.; Gleeson, T.; Wagener, T.; Wada, Y.

    2015-12-01

    Subsurface heterogeneity has an important control on water balance. Groundwater recharge is one of its most relevant processes feeding the world's groundwater storages and therefore supplying fresh water to large parts of the global population for their drinking water and food production. However, large-scale hydrological models do not usually consider subsurface heterogeneity adequately to simulate groundwater recharge. In this study we compare the model simulations of two different representations of the subsurface, one with heterogeneous and the other with homogeneous subsurface, from present day to the future (1991-2099). We look at simulated recharge rates and their inter-annual variability. In addition, we calculate the elasticity of recharge rates concerning climate variability, in terms of annual precipitation, temperature and average intensity during strong rainfall events, to quantify their controls on simulated recharge and how these controls evolve in the future. Our model comparison shows that regions with strong subsurface heterogeneity have enhanced recharge rates with greater inter-annual variability compared to those with more homogenous subsurface properties. Furthermore, the heterogeneous representation shows stronger elasticity concerning climate variability than the homogeneous subsurface representation. This difference tends to increase towards the future. Our results suggest that water management in regions with heterogeneous subsurface can expect a higher water availability than estimated by most of the large-scale simulations. But measures should be taken to prepare for increasingly variable groundwater recharge rates.

  1. Artificial Groundwater Recharge Zones Mapping Using Remote Sensing and GIS: A Case Study in Indian Punjab

    NASA Astrophysics Data System (ADS)

    Singh, Amanpreet; Panda, S. N.; Kumar, K. S.; Sharma, Chandra Shekhar

    2013-07-01

    Artificial groundwater recharge plays a vital role in sustainable management of groundwater resources. The present study was carried out to identify the artificial groundwater recharge zones in Bist Doab basin of Indian Punjab using remote sensing and geographical information system (GIS) for augmenting groundwater resources. The study area has been facing severe water scarcity due to intensive agriculture for the past few years. The thematic layers considered in the present study are: geomorphology (2004), geology (2004), land use/land cover (2008), drainage density, slope, soil texture (2000), aquifer transmissivity, and specific yield. Different themes and related features were assigned proper weights based on their relative contribution to groundwater recharge. Normalized weights were computed using the Saaty's analytic hierarchy process. Thematic layers were integrated in ArcGIS for delineation of artificial groundwater recharge zones. The recharge map thus obtained was divided into four zones (poor, moderate, good, and very good) based on their influence to groundwater recharge. Results indicate that 15, 18, 37, and 30 % of the study area falls under "poor," "moderate," "good," and "very good" groundwater recharge zones, respectively. The highest recharge potential area is located towards western and parts of middle region because of high infiltration rates caused due to the distribution of flood plains, alluvial plain, and agricultural land. The least effective recharge potential is in the eastern and middle parts of the study area due to low infiltration rate. The results of the study can be used to formulate an efficient groundwater management plan for sustainable utilization of limited groundwater resources.

  2. Multi-scale experimental programs for estimating groundwater recharge in hydrologically changing basins

    NASA Astrophysics Data System (ADS)

    McIntyre, Neil; Larsen, Josh; Reading, Lucy; Bulovic, Nevenka; Jarihani, Abdollah; Finch, Warren

    2015-04-01

    Groundwater recharge estimates are required to evaluate sustainable groundwater abstractions and to support groundwater impacts assessments associated with minerals and energy extraction. Increasingly, recharge estimates are also needed for regional and global scale water cycle modelling. This is especially the case in the great arid and semi-arid basins of the world due to increased water scarcity and dependence of ecosystems and livelihoods on their water supplies, and the considerable potential influence of groundwater on the hydrological cycle. Groundwater resources in the semi-arid Surat Basin of south-east Queensland, Australia, support extensive groundwater-dependent ecosystems and have historically been utilised for regional agriculture and urban water-use. Large volumes of water are currently being produced and will continue to do so as a part of coal seam gas extraction. There is considerable uncertainty about the impacts of gas extraction on water resources and the hydrological cycle, and much of this uncertainty stems from our limited knowledge about recharge processes and how to upscale them. Particular questions are about the role of storm events in controlling annual recharge, the relative contributions of local 'recharge zones' versus diffuse recharge and the translation of (relatively easily quantified) shallow drainage estimates to groundwater recharge. A multi-scale recharge research program is addressing these questions, using multiple approaches in estimating groundwater recharge, including plot and catchment scale monitoring, use of remote sensed data and simulation models. Results during the first year of the program have resulted in development of process hypotheses and experimental designs at three field sites representing key gaps in knowledge. The presentation will overview the process of designing the experimental program; how the results from these sites will be integrated with existing knowledge; and how results will be used to advance

  3. Partitioning sources of recharge in environments with groundwater recirculation using carbon-14 and CFC-12

    NASA Astrophysics Data System (ADS)

    Bourke, Sarah A.; Cook, Peter G.; Dogramaci, Shawan; Kipfer, Rolf

    2015-06-01

    Groundwater recirculation occurs when groundwater is pumped from an aquifer onto the land surface, and a portion of that water subsequently infiltrates back to the aquifer. In environments where groundwater is recirculated, differentiation between various sources of recharge (e.g. natural rainfall recharge vs. recirculated water) can be difficult. Groundwater age indicators, in particular transient trace gases, are likely to be more sensitive tracers of recharge than stable isotopes or chloride in this setting. This is because, unlike stable isotopes or chloride, they undergo a process of equilibration with the atmosphere, and historical atmospheric concentrations are known. In this paper, groundwater age indicators (14C and CFC-12) were used as tracers of recharge by surplus mine water that is discharged to streams. Ternary mixing ratios were calculated based on 14C and CFC-12 concentrations measured along three transects of piezometers and monitoring wells perpendicular to the creeks, and from dewatering wells. Uncertainty in calculated mixing ratios was estimated using a Monte Carlo approach. Ternary mixing ratios in dewatering wells suggest that recharge by mine water accounted for between 10% and 87% of water currently abstracted by dewatering wells. The calculated mixing ratios suggest that recharge by mine water extends to a distance of more than 550 m from the creeks. These results are supported by seepage flux estimates based on the water and chloride balance along the creeks, which suggest that 85-90% of mine water discharged to the creeks recharges the aquifer and recharge by mine water extends between 110 and 730 m from the creeks. Mixing calculations based on gaseous groundwater age indicators could also be used to partition recharge associated with agricultural irrigation or artificial wetland supplementation.

  4. Land cover controls on depression-focused recharge: an example from southern Ontario

    NASA Astrophysics Data System (ADS)

    Buttle, J. M.; Greenwood, W. J.

    2015-12-01

    The Oak Ridges Moraine (ORM) is a critical hydrogeologic feature in southern Ontario. Although previous research has highlighted the implications of spatially-focused recharge in closed topographic depressions for regional groundwater resources, such depression-focused recharge (DFR) has not been empirically demonstrated on the ORM. Permeable surficial sands and gravels mantling much of the ORM imply that water fluxes will largely be vertical recharge rather than lateral downslope transfer into depressions. Nevertheless, lateral fluxes may occur in winter and spring, when concrete frost development encourages surface runoff of rainfall and snowmelt. The potential for DFR was examined under forest and agricultural land cover with similar soils and surficial geology. Soil water contents, soil temperatures and ground frost thickness were measured at the crest and base of closed depressions in two agricultural fields and two forest stands on permeable ORM outcrops. Recharge from late-fall to the end of spring snowmelt was estimated via 1-d water balances and surface-applied bromide tracing. Both forest and agricultural sites experienced soil freezing; however, greater soil water contents prior to freeze-up at the latter led to concrete soil frost development. This resulted in lateral movement of snowmelt and rainfall into topographic depressions and surface ponding, which did not occur in forest depressions. Water balance recharge exceeded estimates from the bromide tracer approach at all locations; nevertheless, both methods indicated DRF exceeded recharge at the depression crest in agricultural areas with little difference in forest areas. Water balance estimates suggest winter-spring DFR (1300 - 2000 mm) is 3-5× recharge on level agricultural sites. Differences in the potential for DFR between agricultural and forest land covers have important implications for the spatial variability of recharge fluxes and the quality of recharging water on the ORM.

  5. Estimation of shallow ground-water recharge in the Great Lakes basin

    USGS Publications Warehouse

    Neff, B.P.; Piggott, A.R.; Sheets, R.A.

    2006-01-01

    This report presents the results of the first known integrated study of long-term average ground-water recharge to shallow aquifers (generally less than 100 feet deep) in the United States and Canada for the Great Lakes, upper St. Lawrence, and Ottawa River Basins. The approach used was consistent throughout the study area and allows direct comparison of recharge rates in disparate parts of the study area. Estimates of recharge are based on base-flow estimates for streams throughout the Great Lakes Basin and the assumption that base flow in a given stream is equal to the amount of shallow ground-water recharge to the surrounding watershed, minus losses to evapotranspiration. Base-flow estimates were developed throughout the study area using a single model based on an empirical relation between measured base-flow characteristics at streamflow-gaging stations and the surficial-geologic materials, which consist of bedrock, coarse-textured deposits, fine-textured deposits, till, and organic matter, in the surrounding surface-water watershed. Model calibration was performed using base-flow index (BFI) estimates for 959 stations in the U.S. and Canada using a combined 28,784 years of daily streamflow record determined using the hydrograph-separation software program PART. Results are presented for watersheds represented by 8-digit hydrologic unit code (HUC, U.S.) and tertiary (Canada) watersheds. Recharge values were lowest (1.6-4.0 inches/year) in the eastern Lower Peninsula of Michigan; southwest of Green Bay, Wisconsin; in northwestern Ohio; and immediately south of the St. Lawrence River northeast of Lake Ontario. Recharge values were highest (12-16.8 inches/year) in snow shadow areas east and southeast of each Great Lake. Further studies of deep aquifer recharge and the temporal variability of recharge would be needed to gain a more complete understanding of ground-water recharge in the Great Lakes Basin.

  6. Artificial groundwater recharge zones mapping using remote sensing and GIS: a case study in Indian Punjab.

    PubMed

    Singh, Amanpreet; Panda, S N; Kumar, K S; Sharma, Chandra Shekhar

    2013-07-01

    Artificial groundwater recharge plays a vital role in sustainable management of groundwater resources. The present study was carried out to identify the artificial groundwater recharge zones in Bist Doab basin of Indian Punjab using remote sensing and geographical information system (GIS) for augmenting groundwater resources. The study area has been facing severe water scarcity due to intensive agriculture for the past few years. The thematic layers considered in the present study are: geomorphology (2004), geology (2004), land use/land cover (2008), drainage density, slope, soil texture (2000), aquifer transmissivity, and specific yield. Different themes and related features were assigned proper weights based on their relative contribution to groundwater recharge. Normalized weights were computed using the Saaty's analytic hierarchy process. Thematic layers were integrated in ArcGIS for delineation of artificial groundwater recharge zones. The recharge map thus obtained was divided into four zones (poor, moderate, good, and very good) based on their influence to groundwater recharge. Results indicate that 15, 18, 37, and 30 % of the study area falls under "poor," "moderate," "good," and "very good" groundwater recharge zones, respectively. The highest recharge potential area is located towards western and parts of middle region because of high infiltration rates caused due to the distribution of flood plains, alluvial plain, and agricultural land. The least effective recharge potential is in the eastern and middle parts of the study area due to low infiltration rate. The results of the study can be used to formulate an efficient groundwater management plan for sustainable utilization of limited groundwater resources. PMID:23775493

  7. Artificial groundwater recharge zones mapping using remote sensing and GIS: a case study in Indian Punjab.

    PubMed

    Singh, Amanpreet; Panda, S N; Kumar, K S; Sharma, Chandra Shekhar

    2013-07-01

    Artificial groundwater recharge plays a vital role in sustainable management of groundwater resources. The present study was carried out to identify the artificial groundwater recharge zones in Bist Doab basin of Indian Punjab using remote sensing and geographical information system (GIS) for augmenting groundwater resources. The study area has been facing severe water scarcity due to intensive agriculture for the past few years. The thematic layers considered in the present study are: geomorphology (2004), geology (2004), land use/land cover (2008), drainage density, slope, soil texture (2000), aquifer transmissivity, and specific yield. Different themes and related features were assigned proper weights based on their relative contribution to groundwater recharge. Normalized weights were computed using the Saaty's analytic hierarchy process. Thematic layers were integrated in ArcGIS for delineation of artificial groundwater recharge zones. The recharge map thus obtained was divided into four zones (poor, moderate, good, and very good) based on their influence to groundwater recharge. Results indicate that 15, 18, 37, and 30 % of the study area falls under "poor," "moderate," "good," and "very good" groundwater recharge zones, respectively. The highest recharge potential area is located towards western and parts of middle region because of high infiltration rates caused due to the distribution of flood plains, alluvial plain, and agricultural land. The least effective recharge potential is in the eastern and middle parts of the study area due to low infiltration rate. The results of the study can be used to formulate an efficient groundwater management plan for sustainable utilization of limited groundwater resources.

  8. Silt and gas accumulation beneath an artificial recharge spreading basin, Southwestern Utah, U.S.A.

    USGS Publications Warehouse

    Heilweil, V.M.; Solomon, D.K.; Ortiz, G.

    2009-01-01

    Sand Hollow Reservoir in southwestern Utah, USA, is operated for both surface-water storage and artificial recharge to the underlying Navajo Sandstone. The total volume of estimated artificial recharge between 2002 and 2007 is 85 million cubic meters (69,000 acre-feet). Since 2002, artificial recharge rates have generally been declining and are inversely correlated with the increasing surface area of the reservoir. Permeability testing of core samples retrieved from beneath the reservoir indicates that this decline may not be due to silt accumulation. Artificial recharge rates also show much seasonal variability. Calculations of apparent intrinsic permeability show that these variations can only partly be explained by variation in water viscosity associated with seasonal changes in water temperature. Sporadic seasonal trends in recharge rates and intrinsic permeability during 2002-2004 could be associated with the large fluctuations in reservoir elevation and wetted area. From 2005 through 2007, the reservoir was mostly full and there has been a more consistent seasonal pattern of minimum recharge rates during the summer and maximum rates during the autumn. Total dissolved-gas pressure measurements indicate the presence of biogenic gas bubbles in the shallow sediments beneath the shallower parts of Sand Hollow Reservoir when the water is warmer. Permeability reduction associated with this gas clogging may contribute to the decrease in artificial recharge rates during the spring and summer, with a subsequently increasing recharge rates in the autumn associated with a decline in volume of gas bubbles. Other possible causes for seasonal variation in artificial recharge rates require further investigation.

  9. Comparison of different estimation techniques to quantify groundwater recharge in Pirna, Germany

    NASA Astrophysics Data System (ADS)

    Ringleb, Jana; Sallwey, Jana; Stefan, Catalin

    2015-04-01

    Water scarcity in combination with groundwater exploitation is a major concern worldwide because of climate change, population growth and rising water demand. To be able to sustainably manage and protect groundwater resources, it is necessary to quantify the amount of water which leaks through the unsaturated zone and recharges the aquifer naturally. However, quantifying the spatial and temporal distribution of recharge is difficult because of soil heterogeneity and the influence of vegetation. For that reason and because field measurements of recharge are difficult to obtain, models are valuable tools to quantify recharge. Numerical models need a lot of parameters which are hard to measure and hence can only be estimated. Therefore analytical models or empirical equations which use less and / or easier obtainable parameters could estimate groundwater recharge as well as numerical models because of the underlying uncertainty in parameter estimation. Recharge estimation methods which use different model approaches and have varying complexity were compared at Pirna test field site, Germany to select suitable methods which will later be integrated into a web-based Decision Support System (DSS) developed for the sustainable management of groundwater. The complexity of the used methods covers numerical models, analytical models as well as empirical equations. Different model approaches were used to estimate groundwater recharge including amongst others a groundwater flow model, an unsaturated zone model and a watershed model. The resulting groundwater recharge estimates received from the numerical and analytical models and from empirical equations were compared to evaluate whether the methods are suitable to estimate groundwater recharge considering the complexity, data requirements and time-consumption of each method.