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

2017-07-01

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.

Pressure - temperature estimates of a phengite eclogite from the Grapesvåre Nappe, Norrbotten, Swedish Caledonides

NASA Astrophysics Data System (ADS)

Bukała, Michał; Majka, Jarosław; Walczak, Katarzyna; Barnes, Christopher; Klonowska, Iwona

2017-04-01

The Seve Nappe Complex (SNC) of the Scandinavian Caledonides has well documented history of high pressure (HP) and ultra-high pressure (UHP) metamorphism (e.g. Klonowska et al. 2014). Eclogites of the SNC occur in two areas in Sweden, namely Jämtland and Norrbotten. The Jämtland eclogites and associated rocks are well studied and provide evidence for the Late Ordovician UHP metamorphism, whereas the Norrbotten eclogites, formed during the Late Cambrian/Early Ordovician, have not been studied in detail, especially in terms of pressure-temperature (P-T) conditions of their formation. Within the SNC in Norrbotten, eclogites are limited to two tectonic lenses - Vaimok and Tsäkkok (e.g. Albrecht, 2000). Within the Vaimok Lens three nappes have been distinguished: (1) the eclogite-free Lower Seve Nappe, (2) the Grapesvåre Nappe and (3) the Maddåive Nappe. The two latter nappes are eclogite-bearing. For this study eclogites were collected from the lowermost part of the Grapesvåre Nappe (from the highly heterogeneous Daunasvagge unit dominated by garnet-bearing mica schists, quartzites and marbles). Eclogite boudins (former dolerite dikes and sills) are usually highly altered due to retrogressive recrystallization. Rare fresh eclogites occur within large boudins (>5m in diameter) and display only minor alteration limited to the scarce veinlets composed of amphibole + feldspar + garnet + zoisite + biotite + rutile + titanite. Metamorphic peak conditions mineral assemblage consists of garnet + omphacite + phengite + quartz + rutile. For P-T estimates the geothermobarometric method of Ravna & Terry (2004) has been used. The garnet-clinopyroxene Fe2+-Mg exchange thermometer and the net-transfer reaction barometer based on the garnet-phengite-omphacite equilibrium yielded a maximum pressure of 26.7 kbar and temperature of 677°C. The obtained temperature might be underestimated due to uncertainties in Fe2+/Fe3+ ratio in pyroxene. Therefore Zr-in-rutile geothermometer by

Magnetic fabric of fault breccia: Revealing the direction of the Cretaceous nappe-stacking in the Inner Western Carpathians by AMS analyses

NASA Astrophysics Data System (ADS)

Pomella, Hannah; Kövér, Szilvia; Fodor, László

2017-04-01

The anisotropy of magnetic susceptibility (AMS) has been recognized as a highly sensitive indicator of rock fabric and is widely employed in the field of structural geology. Brittle faults are often characterized by fault breccia, fault rocks with clast-in-matrix textures. A noteworthy feature of the breccia is the presence of a fabric defined by the preferred orientation of clasts and grains in the matrix. However, this fabric is often not visible in the field or in thin sections but can be detected by AMS analyses. The sample area of the present study is located within the Cretaceous thin-skinned nappe-system of the Inner Western Carpathians. This Alpine-type orogenic belt is built up by large-scale, few km thick nappes without connection to their root areas. These thin rock slices thrust over large distances without sign of mayor deformation within the nappe slice. All the deformation took place along highly strained, narrow shear zones lubricated by hot fluids. These hydrostatically pressurized zones develop on the bases of the nappes, where basal tectonic breccia was formed. Newly formed, syn-kinematic minerals are growing from the overpressured fluids. These polymict breccias have typical block-in-matrix texture with clast size vary between mm and few cm. The matrix is mainly submillimetre-scale rock fragments and cement. In spite of detailed studies about the physical conditions of nappe movements, there is no information about the tectonic transport direction. Analyses of brittle fault kinematics within the different tectonic slices suggest either NW-SE or N-S compressional stress field during the nappe-stacking. With this study we want to test if the magnetic fabric of tectonic breccia can help to determine the transport direction. The first results are very promising: Area 1 (basal tectonic breccia from Tisovec): the magnetic lineation is well defined and plunges gently towards N-NNW. The stretching lineation observable in the field within the uppermost

Cathodoluminescence, fluid inclusion and stable C-O isotope study of tectonic breccias from thrusting plane of a thin-skinned calcareous nappe

NASA Astrophysics Data System (ADS)

Milovský, Rastislav; van den Kerkhof, Alfons; Hoefs, Jochen; Hurai, Vratislav; Prochaska, Walter

2012-03-01

Basal hydraulic breccias of alpine thin-skinned Muráň nappe were investigated by means of cathodoluminescence petrography, stable isotope geochemistry and fluid inclusions analysis. Our study reveals an unusual dynamic fluid regime along basal thrust plane during final episode of the nappe emplacement over its metamorphic substratum. Basal thrusting fluids enriched in 18O, silica, alumina, alkalies and phosphates were generated in the underlying metamorphosed basement at epizonal conditions corresponding to the temperatures of 400-450°C. The fluids fluxed the tectonized nappe base, leached evaporite-bearing formations in hangingwall, whereby becoming oversaturated with sulphates and chlorides. The fluids further modified their composition by dedolomitization and isotopic exchange with the host carbonatic cataclasites. Newly formed mineral assemblage of quartz, phlogopite, albite, potassium feldspar, apatite, dravite tourmaline and anhydrite precipitated from these fluids on cooling down to 180-200°C. Finally, the cataclastic mush was cemented by calcite at ambient anchizonal conditions. Recurrent fluid injections as described above probably enhanced the final motion of the Muráň nappe.

Aquifer overexploitation: what does it mean?

NASA Astrophysics Data System (ADS)

Custodio, Emilio

2002-02-01

, the term aquifer overexploitation is mostly a qualifier that intends to point to a concern about the evolution of the aquifer-flow system in some specific, restricted points of view, but without a precise hydrodynamic meaning. Implementing groundwater management and protection measures needs quantitative appraisal of aquifer evolution and effects based on detailed multidisciplinary studies, which have to be supported by reliable data. Resumé. La surexploitation de l'eau souterraine et la surexploitation des nappes sont des termes qui deviennent d'usage commun en gestion de l'eau. Plusieurs hydrologues, aménageurs et journalistes en font usage quand on parle d'une nappe exploitée intensivement et qui présente des situations conflictives. On peut définir la surexploitation comme étant la situation dans laquelle l'extraction moyenne d'eau souterraine est plus grande ou proche de la recharge moyenne pendant quelques années. Mais le taux ansi que la surface de cette recharge sont souvent tres incertains et peuvent changer dûs a des activitées humaines et à l'exploitation de la nappe elle-méme. Du point de vue pratique on souvent considère qu'il y a surexploitation quand on observe or on s'aperçoit de certains résultats négatifs de l'exploitation, tels qu'une diminution continue du niveau de l'eau, une detérioration de sa qualité, une augmentation du coût d' extraction, ou dommages écologiques. Mais ces effets négatifs n' impliquent pas nécessairement que l'extraction soit plus grande que la recharge. Ils peuvent étre simplement le résultat d'interférences ou d'une longue période transitoire qui suivent les changements dans les termes du bilan hydrique. Cette période transitoire a une durée que dépend de la taille de la nappe, et de son coefficient d' emmagasinement et de sa perméabilité. Les extractions d'eau de la nappe comportent une diminution de l'emmagasinement d'eau souterraine pendant le période transitoire. A fin de pouvoir d

Groundwater evolution beneath Hat Yai, a rapidly developing city in Thailand

NASA Astrophysics Data System (ADS)

Lawrence, A. R.; Gooddy, D. C.; Kanatharana, P.; Meesilp, W.; Ramnarong, V.

2000-09-01

Many cities and towns in South and Southeast Asia are unsewered, and urban wastewaters are often discharged either directly to the ground or to surface-water canals and channels. This practice can result in widespread contamination of the shallow groundwater. In Hat Yai, southern Thailand, seepage of urban wastewaters has produced substantial deterioration in the quality of the shallow groundwater directly beneath the city. For this reason, the majority of the potable water supply is obtained from groundwater in deeper semi-confined aquifers 30-50 m below the surface. However, downward leakage of shallow groundwater from beneath the city is a significant component of recharge to the deeper aquifer, which has long-term implications for water quality. Results from cored boreholes and shallow nested piezometers are presented. The combination of high organic content of the urban recharge and the shallow depth to the water table has produced strongly reducing conditions in the upper layer and the mobilisation of arsenic. A simple analytical model shows that time scales for downward leakage, from the surface through the upper aquitard to the semi-confined aquifer, are of the order of several decades. Résumé. De nombreuses villes du sud et du sud-est de l'Asie ne possèdent pas de réseaux d'égouts et les eaux usées domestiques s'écoulent souvent directement sur le sol ou dans des canaux et des cours d'eau de surface. Ces pratiques peuvent provoquer une contamination dispersée de la nappe phréatique. A Hat Yai (sud de la Thaïlande), les infiltrations d'eaux usées domestiques sont responsables d'une détérioration notable de la qualité de la nappe phréatique directement sous la ville. Pour cette raison, la majorité de l'eau potable est prélevée dans des aquifères semi-captifs plus profonds, situés entre 30 et 50 m sous la surface. Cependant, une drainance à partir de la nappe phréatique sous la ville constitue une composante significative de la recharge

Pseudo- and real-inverted metamorphism caused by the superposition and extrusion of a stack of nappes: a case study of the Southern Brasília Orogen, Brazil

NASA Astrophysics Data System (ADS)

da Motta, Rafael Gonçalves; Moraes, Renato

2017-10-01

The Southern Brasília Orogen is a Neoproterozoic belt that occurs along the southernmost border of the São Francisco Craton where the Andrelândia Nappe System represents the subducted sedimentary domain and is divided into three allochthonous groups, of which the ages and P-T conditions of metamorphism are studied here. The basal unit, the Andrelândia Nappe, exhibits an inverted metamorphic pattern. The base of the structure, composed of staurolite, garnet, biotite, kyanite, quartz, and muscovite, marks the metamorphic peak, whereas at the top, the association of the metamorphic peak does not contain staurolite. The Liberdade Nappe, the middle unit, presents a normal metamorphic pattern; its base, close to the Andrelândia Nappe, shows paragneiss with evidence of in situ partial melting, and towards the top, coarse-grained staurolite schist is found. The staurolite-out and melt-in isograds are coincident and parallel to the main foliation. Thus, the shear zone that limits the nappes is syn-metamorphic, reheating the underlying Andrelândia Nappe and influencing the establishment of metamorphic inversion. This suggestion is supported by the monazite chemical ages, which indicates that the Andrelândia Nappe metamorphic peak (586 ± 15 Ma) is younger than that of the Liberdade Nappe (622.3 ± 7.6 Ma). The upper unit, the Serra da Natureza Klippe, bears a typical high-pressure granulite mineral assemblage that is composed of kyanite, garnet, K-feldspar, rutile, and leucosome, as well as a metamorphic peak at 604.5 ± 6.1 Ma. This tectonic assembly, with inverted and non-inverted metamorphic patterns and generation of klippen structures, is consistent with exhumation models and a strong indentor located in the lower continental crust.

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

Hydrocarbon potential of the Early Oligocene Menilite shales in the Eastern Outer Carpathians (Tarcău and Vrancea Nappes, Romania)

NASA Astrophysics Data System (ADS)

Wendorff, Małgorzata; Rospondek, Mariusz; Kluska, Bartosz; Marynowski, Leszek

2017-04-01

During Oligocene to early Miocene time an extensive accumulation of organic-rich sedimentary rocks occurred in entire Paratethyan Basin, including its central part, i.e. the Carpathian Foredeep basin. Rocks of so-called Menilite facies formed there, burying significant amounts of organic matter (OM). These Menilite shales are now widely considered as a source of hydrocarbons throughout the Carpathian region. For the purpose of presented study, rock samples of the Menilite facies (mainly of the Lower Menilite and Bituminous Marl Members) were collected from two sections located in the different tectonic units (the Tarcău and Vrancea Nappes, Romania) of the Outer Carpathians. The main goal of the study was to assess and compare their hydrocarbon potential by examination of bulk geochemistry (total organic carbon content, pyrolysis Rock-Eval), vitrinite reflectance (Ro) and application of lipid biomarker parameters. The data show high variability in OM quantity and quality. Total organic carbon (TOC) content reaches peak values in the siliceous facies of the Lower Menilite Member (up to 8.6 wt% TOC), which contains type II kerogen represented by mainly marine OM type. Such results are confirmed by the presence of short-chain n-alkanes and hopanes. Mixed type II/III kerogen gains importance together with increasing contribution of turbiditic sedimentation. Terrigenous input is marked by occurrence of conifer aromatic biomarkers (such as simonellite, retene and 1,2,3,4-tetrahydroretene) and odd over even long chain n-alkanes predominance, characteristic for epicuticular leaf waxes. The analysed source rocks can be classified as oil-prone and subordinately mixed oil/gas-prone. OM in the inner tectonic unit (Tarcău Nappe; Tmax 430° C, Ro 0.5%) reaches onset of hydrocarbon generation, while in the outer unit (Vrancea Nappe) OM is immature (Tmax 425° C, Ro 0.4%). This maturity trend may be an effect of different burial histories of these units, as well as variation in

Eclogite nappe-stack in the Grivola-Urtier Ophiolites (Southern Aosta Valley, Western Alps)

NASA Astrophysics Data System (ADS)

Tartarotti, Paola

2013-04-01

In the Western Alpine chain, ophiolites represent a section of the Mesozoic Tethys oceanic lithosphere, involved in subduction during the convergence between the paleo-Africa and paelo-Europe continents during the Cretaceous - Eocene. The Western Alpine ophiolites consist of several tectonic units, the most famous being the Zermatt-Saas and Combin nappes, and other major ophiolite bodies as the Voltri, Monviso, and Rocciavrè that show different rock assemblages and contrasting metamorphic imprints. The Grivola-Urtier (GU) unit is exposed in the southern Aosta Valley, covering an area of about 100 km2; it is tectonically sandwiched between the continentally-derived Pennidic Gran Paradiso Nappe below, and the Austroalpine Mount Emilius klippe above. This unit has been so far considered as part of the Zermatt-Saas nappe extending from the Saas-Fee area (Switzerland) to the Aosta Valley (Italy). The GU unit consists of serpentinized peridotites that include pods and boudinaged layers of eclogitic Fe-metagabbro and trondhjemite, rodingites and chloriteschists transposed in the main foliation together with calcschists and micaschists. All rocks preserve particularly fresh eclogitic mineral assemblages. The contact between the serpentinites and calcshists is marked by a tectonic mélange consisting of mylonitic marble and calcschist with stretched and boudinaged serpentinite blocks. Continentally-derived allochthonous blocks ranging in size from100 meters to meters are also included within the ophiolites. New field, petrographic and geochemical data reveal the complex nature of the fossil Tethyan oceanic lithosphere exposed in the southern Aosta Valley, as well as the extent and size of the continental-oceanic tectonic mélange. The geological setting of the GU unit is here inferred as a key tool for understanding the complex architecture of the ophiolites in the Western Alps.

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

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

Management decision of optimal recharge water in groundwater artificial recharge conditions- A case study in an artificial recharge test site

NASA Astrophysics Data System (ADS)

He, H. Y.; Shi, X. F.; Zhu, W.; Wang, C. Q.; Ma, H. W.; Zhang, W. J.

2017-11-01

The city conducted groundwater artificial recharge test which was taken a typical site as an example, and the purpose is to prevent and control land subsidence, increase the amount of groundwater resources. To protect groundwater environmental quality and safety, the city chose tap water as recharge water, however, the high cost makes it not conducive to the optimal allocation of water resources and not suitable to popularize widely. To solve this, the city selects two major surface water of River A and B as the proposed recharge water, to explore its feasibility. According to a comprehensive analysis of the cost of recharge, the distance of the water transport, the quality of recharge water and others. Entropy weight Fuzzy Comprehensive Evaluation Method is used to prefer tap water and water of River A and B. Evaluation results show that water of River B is the optimal recharge water, if used; recharge cost will be from 0.4724/m3 to 0.3696/m3. Using Entropy weight Fuzzy Comprehensive Evaluation Method to confirm water of River B as optimal water is scientific and reasonable. The optimal water management decisions can provide technical support for the city to carry out overall groundwater artificial recharge engineering in deep aquifer.

Re-evaluation of polyphase kinematic and 40Ar/39Ar cooling history of Moldanubian hot nappe at the eastern margin of the Bohemian Massif

NASA Astrophysics Data System (ADS)

Racek, M.; Lexa, O.; Schulmann, K.; Corsini, M.; Štípská, P.; Maierová, P.

2017-03-01

A structural and geochronological 40Ar/39Ar study was performed in kilometre-scale middle and lower crustal lens-shaped domains dominated by a preserved subvertical foliation, surrounded by horizontally foliated migmatites. These domains occur within the Moldanubian nappe overlying the Brunia microcontinent at the eastern margin of the European Variscides. Three main deformation phases were recognized: subvertical S2 fabric trending NW-SE in lower crustal rocks and NE-SW in mid-crustal rocks. It is reworked by HT/MT horizontal fabric S3 along margins of crustal domains and in surrounding migmatites. S3 bears a prolate NE lineation parallel to the S2-S3 intersection in the lower crustal domain. In the middle crustal units, L3 is weak, connected to oblate strain and trends NE-SW parallel to the S2-S3 intersection. D4 non-coaxial shear deformation is mainly localized at the boundary between the Moldanubian nappe and Brunia and bears strong top to the NNE shear criteria. In order to constrain kinematics of the D3 deformation, strain modelling was performed to show that the Moldanubian hot nappe was frontally thrust over the Brunia indentor. The renewed D4 tangential movement only heterogeneously reactivates the horizontal S3. This evolution is recorded in 40Ar/39Ar amphibole cooling ages, which show two statistically significant Carboniferous peaks at 342 and 332 Ma, which are also reflected by published detrital muscovite 40Ar/39Ar ages in the adjacent foreland basin. This geochronological record is correlated with progressive erosion of the topographically elevated upper crustal part of the Moldanubian nappe during D3 frontal thrusting, followed by greenschist facies D4 transpressive reactivation and subsequent erosion of high-grade parts of the nappe.

Enhanced recharge rates and altered recharge sensitivity to climate variability through subsurface heterogeneity

NASA Astrophysics Data System (ADS)

Hartmann, Andreas; Gleeson, Tom; Wada, Yoshihide; Wagener, Thorsten

2017-04-01

Karst aquifers in Europe are an important source of fresh water contributing up to half of the total drinking water supply in some countries. Karstic groundwater recharge is one of the most important components of the water balance of karst systems as it feeds the karst aquifers. Presently available large-scale hydrological models do not consider karst heterogeneity adequately. Projections of current and potential future groundwater recharge of Europe's karst aquifers are therefore unclear. In this study we compare simulations of present (1991-2010) and future (2080-2099) recharge using two different models to simulate groundwater recharge processes. One model includes karst processes (subsurface heterogeneity, lateral flow and concentrated recharge), while the other is based on the conceptual understanding of common hydrological systems (homogeneous subsurface, saturation excess overland flow). Both models are driven by the bias-corrected 5 GCMs of the ISI-MIP project (RCP8.5). To further assess sensitivity of groundwater recharge to climate variability, we calculate the elasticity of recharge rates to annual precipitation, temperature and average intensity of rainfall events, which is the median change of recharge that corresponds to the median change of these climate variables within the present and future time period, respectively. Our model comparison shows that karst regions over Europe 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 current large-scale simulations, while measures should be taken to prepare for increasingly

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.

Middle Ordovician subduction of continental crust in the Scandinavian Caledonides: an example from Tjeliken, Seve Nappe Complex, Sweden

NASA Astrophysics Data System (ADS)

Fassmer, Kathrin; Klonowska, Iwona; Walczak, Katarzyna; Andersson, Barbro; Froitzheim, Nikolaus; Majka, Jarosław; Fonseca, Raúl O. C.; Münker, Carsten; Janák, Marian; Whitehouse, Martin

2017-12-01

The Seve Nappe Complex of the Scandinavian Caledonides is thought to be derived from the distal passive margin of Baltica which collided with Laurentia in the Scandian Phase of the Caledonian Orogeny at 430-400 Ma. Parts of the Seve Nappe Complex were affected by pre-Scandian high- and ultrahigh-pressure metamorphism, in a tectonic framework that is still unclear, partly due to uncertainties about the exact timing. Previous age determinations yielded between 505 and 446 Ma, with a general trend of older ages in the North (Norrbotten) than in the South (Jämtland). New age determinations were performed on eclogite and garnet-phengite gneiss at Tjeliken in northern Jämtland. Thermodynamic modelling yielded peak metamorphic conditions of 25-27 kbar/680-760 °C for the garnet-phengite gneiss, similar to published peak metamorphic conditions of the eclogite (25-26 kbar/650-700 °C). Metamorphic rims of zircons from the garnet-phengite gneiss were dated using secondary ion mass spectrometry and yielded a concordia age of 458.9 ± 2.5 Ma. Lu-Hf garnet-whole rock dating yielded 458 ± 1.0 Ma for the eclogite. Garnet in the eclogite shows prograde major-element zoning and concentration of Lu in the cores, indicating that this age is related to garnet growth during pressure increase, i.e. subduction. The identical ages from both rock types, coinciding with published Sm-Nd ages from the eclogite, confirm subduction of the Seve Nappe Complex in Northern Jämtland during the Middle Ordovician in a fast subduction-exhumation cycle.

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.

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.

Estimating groundwater recharge

USGS Publications Warehouse

Healy, Richard W.; Scanlon, Bridget R.

2010-01-01

Understanding groundwater recharge is essential for successful management of water resources and modeling fluid and contaminant transport within the subsurface. This book provides a critical evaluation of the theory and assumptions that underlie methods for estimating rates of groundwater recharge. Detailed explanations of the methods are provided - allowing readers to apply many of the techniques themselves without needing to consult additional references. Numerous practical examples highlight benefits and limitations of each method. Approximately 900 references allow advanced practitioners to pursue additional information on any method. For the first time, theoretical and practical considerations for selecting and applying methods for estimating groundwater recharge are covered in a single volume with uniform presentation. Hydrogeologists, water-resource specialists, civil and agricultural engineers, earth and environmental scientists and agronomists will benefit from this informative and practical book. It can serve as the primary text for a graduate-level course on groundwater recharge or as an adjunct text for courses on groundwater hydrology or hydrogeology.

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

Multiple recharge processes to heterogeneous Mediterranean coastal aquifers and implications on recharge rates evolution in time

NASA Astrophysics Data System (ADS)

Santoni, S.; Huneau, F.; Garel, E.; Celle-Jeanton, H.

2018-04-01

Climate change is nowadays widely considered to have major effects on groundwater resources. Climatic projections suggest a global increase in evaporation and higher frequency of strong rainfall events especially in Mediterranean context. Since evaporation is synonym of low recharge conditions whereas strong rainfall events are more favourable to recharge in heterogeneous subsurface contexts, a lack of knowledge remains then on the real ongoing and future drinking groundwater supply availability at aquifers scale. Due to low recharge potential and high inter-annual climate variability, this issue is strategic for the Mediterranean hydrosystems. This is especially the case for coastal aquifers because they are exposed to seawater intrusion, sea-level rise and overpumping risks. In this context, recharge processes and rates were investigated in a Mediterranean coastal aquifer with subsurface heterogeneity located in Southern Corsica (France). Aquifer recharge rates from combining ten physical and chemical methods were computed. In addition, hydrochemical and isotopic investigations were carried out through a monthly two years monitoring combining major ions and stable isotopes of water in rain, runoff and groundwater. Diffuse, focused, lateral mountain system and irrigation recharge processes were identified and characterized. A predominant focused recharge conditioned by subsurface heterogeneity is evidenced in agreement with variable but highly favourable recharge rates. The fast water transfer from the surface to the aquifer implied by this recharge process suggests less evaporation, which means higher groundwater renewal and availability in such Mediterranean coastal aquifers.

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

Summary of groundwater-recharge estimates for Pennsylvania

USGS Publications Warehouse

Stuart O. Reese,; Risser, Dennis W.

2010-01-01

Groundwater recharge is water that infiltrates through the subsurface to the zone of saturation beneath the water table. Because recharge is a difficult parameter to quantify, it is typically estimated from measurements of other parameters like streamflow and precipitation. This report provides a general overview of processes affecting recharge in Pennsylvania and presents estimates of recharge rates from studies at various scales.The most common method for estimating recharge in Pennsylvania has been to estimate base flow from measurements of streamflow and assume that base flow (expressed in inches over the basin) approximates recharge. Statewide estimates of mean annual groundwater recharge were developed by relating base flow to basin characteristics of HUC10 watersheds (a fifth-level classification that uses 10 digits to define unique hydrologic units) using a regression equation. The regression analysis indicated that mean annual precipitation, average daily maximum temperature, percent of sand in soil, percent of carbonate rock in the watershed, and average stream-channel slope were significant factors in the explaining the variability of groundwater recharge across the Commonwealth.Several maps are included in this report to illustrate the principal factors affecting recharge and provide additional information about the spatial distribution of recharge in Pennsylvania. The maps portray the patterns of precipitation, temperature, prevailing winds across Pennsylvania’s varied physiography; illustrate the error associated with recharge estimates; and show the spatial variability of recharge as a percent of precipitation. National, statewide, regional, and local values of recharge, based on numerous studies, are compiled to allow comparison of estimates from various sources. Together these plates provide a synopsis of groundwater-recharge estimations and factors in Pennsylvania.Areas that receive the most recharge are typically those that get the most

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

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

NASA Astrophysics Data System (ADS)

Sarma, Diganta; Xu, Yongxin

2017-01-01

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.

Enhanced groundwater recharge rates and altered recharge sensitivity to climate variability through subsurface heterogeneity

PubMed Central

Hartmann, Andreas; Gleeson, Tom; Wagener, Thorsten

2017-01-01

Our environment is heterogeneous. In hydrological sciences, the heterogeneity of subsurface properties, such as hydraulic conductivities or porosities, exerts an important control on water balance. This notably includes groundwater recharge, which is an important variable for efficient and sustainable groundwater resources management. Current large-scale hydrological models do not adequately consider this subsurface heterogeneity. Here we show that regions with strong subsurface heterogeneity have enhanced present and future recharge rates due to a different sensitivity of recharge to climate variability compared with regions with homogeneous subsurface properties. Our study domain comprises the carbonate rock regions of Europe, Northern Africa, and the Middle East, which cover ∼25% of the total land area. We compare the simulations of two large-scale hydrological models, one of them accounting for subsurface heterogeneity. Carbonate rock regions strongly exhibit “karstification,” which is known to produce particularly strong subsurface heterogeneity. Aquifers from these regions contribute up to half of the drinking water supply for some European countries. Our results suggest that water management for these regions cannot rely on most of the presently available projections of groundwater recharge because spatially variable storages and spatial concentration of recharge result in actual recharge rates that are up to four times larger for present conditions and changes up to five times larger for potential future conditions than previously estimated. These differences in recharge rates for strongly heterogeneous regions suggest a need for groundwater management strategies that are adapted to the fast transit of water from the surface to the aquifers. PMID:28242703

Enhanced Groundwater Recharge Rates and Altered Recharge Sensitivity to Climate Variability Through Subsurface Heterogeneity

NASA Technical Reports Server (NTRS)

Hartmann, Andreas; Gleeson, Tom; Wada, Yoshihide; Wagener, Thorsten

2017-01-01

Our environment is heterogeneous. In hydrological sciences, the heterogeneity of subsurface properties, such as hydraulic conductivities or porosities, exerts an important control on water balance. This notably includes groundwater recharge, which is an important variable for efficient and sustainable groundwater resources management. Current large-scale hydrological models do not adequately consider this subsurface heterogeneity. Here we show that regions with strong subsurface heterogeneity have enhanced present and future recharge rates due to a different sensitivity of recharge to climate variability compared with regions with homogeneous subsurface properties. Our study domain comprises the carbonate rock regions of Europe, Northern Africa, and the Middle East, which cover 25 of the total land area. We compare the simulations of two large-scale hydrological models, one of them accounting for subsurface heterogeneity. Carbonate rock regions strongly exhibit karstification, which is known to produce particularly strong subsurface heterogeneity. Aquifers from these regions contribute up to half of the drinking water supply for some European countries. Our results suggest that water management for these regions cannot rely on most of the presently available projections of groundwater recharge because spatially variable storages and spatial concentration of recharge result in actual recharge rates that are up to four times larger for present conditions and changes up to five times larger for potential future conditions than previously estimated. These differences in recharge rates for strongly heterogeneous regions suggest a need for groundwater management strategies that are adapted to the fast transit of water from the surface to the aquifers.

Comparing groundwater recharge and storage variability from GRACE satellite observations with observed water levels and recharge model simulations

NASA Astrophysics Data System (ADS)

Allen, D. M.; Henry, C.; Demon, H.; Kirste, D. M.; Huang, J.

2011-12-01

Sustainable management of groundwater resources, particularly in water stressed regions, requires estimates of groundwater recharge. This study in southern Mali, Africa compares approaches for estimating groundwater recharge and understanding recharge processes using a variety of methods encompassing groundwater level-climate data analysis, GRACE satellite data analysis, and recharge modelling for current and future climate conditions. Time series data for GRACE (2002-2006) and observed groundwater level data (1982-2001) do not overlap. To overcome this problem, GRACE time series data were appended to the observed historical time series data, and the records compared. Terrestrial water storage anomalies from GRACE were corrected for soil moisture (SM) using the Global Land Data Assimilation System (GLDAS) to obtain monthly groundwater storage anomalies (GRACE-SM), and monthly recharge estimates. Historical groundwater storage anomalies and recharge were determined using the water table fluctuation method using observation data from 15 wells. Historical annual recharge averaged 145.0 mm (or 15.9% of annual rainfall) and compared favourably with the GRACE-SM estimate of 149.7 mm (or 14.8% of annual rainfall). Both records show lows and peaks in May and September, respectively; however, the peak for the GRACE-SM data is shifted later in the year to November, suggesting that the GLDAS may poorly predict the timing of soil water storage in this region. Recharge simulation results show good agreement between the timing and magnitude of the mean monthly simulated recharge and the regional mean monthly storage anomaly hydrograph generated from all monitoring wells. Under future climate conditions, annual recharge is projected to decrease by 8% for areas with luvisols and by 11% for areas with nitosols. Given this potential reduction in groundwater recharge, there may be added stress placed on an already stressed resource.

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.

Quantifying macropore recharge: Examples from a semi-arid area

USGS Publications Warehouse

Wood, W.W.; Rainwater, Ken 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

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

Identifying and quantifying urban recharge: a review

NASA Astrophysics Data System (ADS)

Lerner, David N.

2002-02-01

The sources of and pathways for groundwater recharge in urban areas are more numerous and complex than in rural environments. Buildings, roads, and other surface infrastructure combine with man-made drainage networks to change the pathways for precipitation. Some direct recharge is lost, but additional recharge can occur from storm drainage systems. Large amounts of water are imported into most cities for supply, distributed through underground pipes, and collected again in sewers or septic tanks. The leaks from these pipe networks often provide substantial recharge. Sources of recharge in urban areas are identified through piezometry, chemical signatures, and water balances. All three approaches have problems. Recharge is quantified either by individual components (direct recharge, water-mains leakage, septic tanks, etc.) or holistically. Working with individual components requires large amounts of data, much of which is uncertain and is likely to lead to large uncertainties in the final result. Recommended holistic approaches include the use of groundwater modelling and solute balances, where various types of data are integrated. Urban recharge remains an under-researched topic, with few high-quality case studies reported in the literature.

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

Statewide Groundwater Recharge Modeling in New Mexico

NASA Astrophysics Data System (ADS)

Xu, F.; Cadol, D.; Newton, B. T.; Phillips, F. M.

2017-12-01

It is crucial to understand the rate and distribution of groundwater recharge in New Mexico because it not only largely defines a limit for water availability in this semi-arid state, but also is the least understood aspect of the state's water budget. With the goal of estimating groundwater recharge statewide, we are developing the Evapotranspiration and Recharge Model (ETRM), which uses existing spatial datasets to model the daily soil water balance over the state at a resolution of 250 m cell. The input datasets includes PRISM precipitation data, MODIS Normalized Difference Vegetation Index (NDVI), NRCS soils data, state geology data and reference ET estimates produced by Gridded Atmospheric Data downscalinG and Evapotranspiration Tools (GADGET). The current estimated recharge presents diffuse recharge only, not focused recharge as in channels or playas. Direct recharge measurements are challenging and rare, therefore we estimate diffuse recharge using a water balance approach. The ETRM simulated runoff amount was compared with USGS gauged discharge in four selected ephemeral channels: Mogollon Creek, Zuni River, the Rio Puerco above Bernardo, and the Rio Puerco above Arroyo Chico. Result showed that focused recharge is important, and basin characteristics can be linked with watershed hydrological response. As the sparse instruments in NM provide limited help in improving estimation of focused recharge by linking basin characteristics, the Walnut Gulch Experimental Watershed, which is one of the most densely gauged and monitored semiarid rangeland watershed for hydrology research purpose, is now being modeled with ETRM. Higher spatial resolution of field data is expected to enable detailed comparison of model recharge results with measured transmission losses in ephemeral channels. The final ETRM product will establish an algorithm to estimate the groundwater recharge as a water budget component of the entire state of New Mexico. Reference ET estimated by GADGET

Monitoring and modeling infiltration-recharge dynamics of managed aquifer recharge with desalinated seawater

NASA Astrophysics Data System (ADS)

Ganot, Yonatan; Holtzman, Ran; Weisbrod, Noam; Nitzan, Ido; Katz, Yoram; Kurtzman, Daniel

2017-09-01

We study the relation between surface infiltration and groundwater recharge during managed aquifer recharge (MAR) with desalinated seawater in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. We monitor infiltration dynamics at multiple scales (up to the scale of the entire pond) by measuring the ponding depth, sediment water content and groundwater levels, using pressure sensors, single-ring infiltrometers, soil sensors, and observation wells. During a month (January 2015) of continuous intensive MAR (2.45 × 106 m3 discharged to a 10.7 ha area), groundwater level has risen by 17 m attaining full connection with the pond, while average infiltration rates declined by almost 2 orders of magnitude (from ˜ 11 to ˜ 0.4 m d-1). This reduction can be explained solely by the lithology of the unsaturated zone that includes relatively low-permeability sediments. Clogging processes at the pond-surface - abundant in many MAR operations - are negated by the high-quality desalinated seawater (turbidity ˜ 0.2 NTU, total dissolved solids ˜ 120 mg L-1) or negligible compared to the low-permeability layers. Recharge during infiltration was estimated reasonably well by simple analytical models, whereas a numerical model was used for estimating groundwater recharge after the end of infiltration. It was found that a calibrated numerical model with a one-dimensional representative sediment profile is able to capture MAR dynamics, including temporal reduction of infiltration rates, drainage and groundwater recharge. Measured infiltration rates of an independent MAR event (January 2016) fitted well to those calculated by the calibrated numerical model, showing the model validity. The successful quantification methodologies of the temporal groundwater recharge are useful for MAR practitioners and can serve as an input for groundwater flow models.

Basement diapirism associated with the emplacement of major ophiolite nappes: Some constraints

NASA Astrophysics Data System (ADS)

Andrews-Speed, C. P.; Johns, C. C.

1985-09-01

The association of basement uplifts with major ophiolite nappes in some Phanerozoic orogenic belts suggests that gravitational instability results in the local diapiric uplift of the basement following ophiolite emplacement. In previous analyses of diapirism in crustal silicate rocks, viscous behaviour of rocks has been assumed. It is argued that this assumption is not valid. An alternative analysis is offered to determine whether or not the stress would be sufficient for diapirism to occur. The negative buoyancy stress resulting from the emplacement of an ophiolite nappe 5-15 km thick onto continental basement may be in the range 10-50 MPa. If the horizontal deviatoric stress is zero, this will be the maximum principal compressive stress. After ophiolite emplacement the thermal profile through the ophiolite and the basement will relax from a saw-tooth form to an equilibrium profile. If the ophiolite is young and thick there will be a zone of ductile strain in the lower part of the ophiolite and in the upper part of the continental basement. Results from steady-state creep experiments suggest that temperatures in this zone may be high enough for a short time after ophiolite emplacement (3 Ma or more) for the rocks in this zone to deform at geologically significant strain rates (10 -14 or greater) in response to the negative buoyancy stress. A thin ophiolite or rapid erosion will result in this ductile zone being absent or too short-lived for significant strain. Aquaeous fluids may reduce the strength of brittle rocks by decreasing the effective normal stress or by encouraging pressure solution creep. Evidence suggests that the deviatoric stress across presently active faults may be as low at 10 MPa. Thus diapirism in response to ophiolite emplacement may occur through brittle strain. Gravity spreading within the ophiolite is an alternative mechanism for accommodating the gravitational instability. The critical evidence lies in the field.

Recharge at the Hanford Site: Status report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gee, G.W.

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 wheremore » 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.« less

Geological structure, recharge processes and underground drainage of a glacierised karst aquifer system, Tsanfleuron-Sanetsch, Swiss Alps

NASA Astrophysics Data System (ADS)

Gremaud, Vivian; Goldscheider, Nico; Savoy, Ludovic; Favre, Gérald; Masson, Henri

2009-12-01

The relationships between stratigraphic and tectonic setting, recharge processes and underground drainage of the glacierised karst aquifer system ‘Tsanfleuron-Sanetsch’ in the Swiss Alps have been studied by means of various methods, particularly tracer tests (19 injections). The area belongs to the Helvetic nappes and consists of Jurassic to Palaeogene sedimentary rocks. Strata are folded and form a regional anticlinorium. Cretaceous Urgonian limestone constitutes the main karst aquifer, overlain by a retreating glacier in its upper part. Polished limestone surfaces are exposed between the glacier front and the end moraine of 1855/1860 (Little Ice Age); typical alpine karrenfields can be observed further below. Results show that (1) large parts of the area are drained by the Glarey spring, which is used as a drinking water source, while marginal parts belong to the catchments of other springs; (2) groundwater flow towards the Glarey spring occurs in the main aquifer, parallel to stratification, while flow towards another spring crosses the entire stratigraphic sequence, consisting of about 800 m of marl and limestone, along deep faults that were probably enlarged by mass movements; (3) the variability of glacial meltwater production influences the shape of the tracer breakthrough curves and, consequently, flow and transport in the aquifer.

Cost profiles and budget impact of rechargeable versus non-rechargeable sacral neuromodulation devices in the treatment of overactive bladder syndrome.

PubMed

Noblett, Karen L; Dmochowski, Roger R; Vasavada, Sandip P; Garner, Abigail M; Liu, Shan; Pietzsch, Jan B

2017-03-01

Sacral neuromodulation (SNM) is a guideline-recommended third-line treatment option for managing overactive bladder. Current SNM devices are not rechargeable, and require neurostimulator replacement every 3-6 years. Our study objective was to assess potential cost effects to payers of adopting a rechargeable SNM neurostimulator device. We constructed a cost-consequence model to estimate the costs of long-term SNM-treatment with a rechargeable versus non-rechargeable device. Costs were considered from the payer perspective at 2015 reimbursement levels. Adverse events, therapy discontinuation, and programming rates were based on the latest published data. Neurostimulator longevity was assumed to be 4.4 and 10.0 years for non-rechargeable and rechargeable devices, respectively. A 15-year horizon was modeled, with costs discounted at 3% per year. Total budget impact to the United States healthcare system was estimated based on the computed per-patient cost findings. Over the 15-year horizon, per-patient cost of treatment with a non-rechargeable device was $64,111 versus $36,990 with a rechargeable device, resulting in estimated payer cost savings of $27,121. These cost savings were found to be robust across a wide range of scenarios. Longer analysis horizon, younger patient age, and longer rechargeable neurostimulator lifetime were associated with increased cost savings. Over a 15-year horizon, adoption of a rechargeable device strategy was projected to save the United States healthcare system up to $12 billion. At current reimbursement rates, our analysis suggests that rechargeable neurostimulator SNM technology for managing overactive bladder syndrome may deliver significant cost savings to payers over the course of treatment. Neurourol. Urodynam. 36:727-733, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Quantification of groundwater recharge in urban environments.

PubMed

Tubau, Isabel; Vázquez-Suñé, Enric; Carrera, Jesús; Valhondo, Cristina; Criollo, Rotman

2017-08-15

Groundwater management in urban areas requires a detailed knowledge of the hydrogeological system as well as the adequate tools for predicting the amount of groundwater and water quality evolution. In that context, a key difference between urban and natural areas lies in recharge evaluation. A large number of studies have been published since the 1990s that evaluate recharge in urban areas, with no specific methodology. Most of these methods show that there are generally higher rates of recharge in urban settings than in natural settings. Methods such as mixing ratios or groundwater modeling can be used to better estimate the relative importance of different sources of recharge and may prove to be a good tool for total recharge evaluation. However, accurate evaluation of this input is difficult. The objective is to present a methodology to help overcome those difficulties, and which will allow us to quantify the variability in space and time of the recharge into aquifers in urban areas. Recharge calculations have been initially performed by defining and applying some analytical equations, and validation has been assessed based on groundwater flow and solute transport modeling. This methodology is applicable to complex systems by considering temporal variability of all water sources. This allows managers of urban groundwater to evaluate the relative contribution of different recharge sources at a city scale by considering quantity and quality factors. The methodology is applied to the assessment of recharge sources in the Barcelona city aquifers. Copyright © 2017 Elsevier B.V. All rights reserved.

SWB Groundwater Recharge Analysis, Catalina Island, California: Assessing Spatial and Temporal Recharge Patterns Within a Mediterranean Climate Zone

NASA Astrophysics Data System (ADS)

Harlow, J.

2017-12-01

Groundwater recharge quantification is a key parameter for sustainable groundwater management. Many recharge quantification techniques have been devised, each with advantages and disadvantages. A free, GIS based recharge quantification tool - the Soil Water Balance (SWB) model - was developed by the USGS to produce fine-tuned recharge constraints in watersheds and illuminate spatial and temporal dynamics of recharge. The subject of this research is to examine SWB within a Mediterranean climate zone, focusing on the Catalina Island, California. This project relied on publicly available online resources with the exception the geospatial processing software, ArcGIS. Daily climate station precipitation and temperature data was obtained from the Desert Research Institute for the years 2008-2014. Precipitation interpolations were performed with ArcGIS using the Natural Neighbor method. The USGS-National Map Viewer (NMV) website provided a 30-meter DEM - to interpolate high and low temperature ASCII grids using the Temperature Lapse Rate (TLR) method, to construct a D-8 flow direction grid for downhill redirection of soil-moisture saturated runoff toward non-saturated cells, and for aesthetic map creation. NMV also provided a modified Anderson land cover classification raster. The US Department of Agriculture-National Resource Conservation Service (NRCS) Web Soil Survey website provided shapefiles of soil water capacity and hydrologic soil groups. The Hargreaves and Samani method was implemented to determine evapotranspiration rates. The resulting SWB output data, in the form of ASCII grids are easily added to ArcGIS for quick visualization and data analysis (Figure 1). Calculated average recharge for 2008-2014 was 3537 inches/year, or 0.0174 acre feet/year. Recharge was 10.2% of the islands gross precipitation. The spatial distribution of the most significant recharge is in hotspots which dominate the residential hills above Avalon, followed by grassy/unvegetated areas

Novel rechargeable calcium phosphate nanoparticle-containing orthodontic cement

PubMed Central

Xie, Xian-Ju; Xing, Dan; Wang, Lin; Zhou, Han; Weir, Michael D; Bai, Yu-Xing; Xu, Hockin HK

2017-01-01

White spot lesions (WSLs), due to enamel demineralization, occur frequently in orthodontic treatment. We recently developed a novel rechargeable dental composite containing nanoparticles of amorphous calcium phosphate (NACP) with long-term calcium (Ca) and phosphate (P) ion release and caries-inhibiting capability. The objectives of this study were to develop the first NACP-rechargeable orthodontic cement and investigate the effects of recharge duration and frequency on the efficacy of ion re-release. The rechargeable cement consisted of pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA). NACP was mixed into the resin at 40% by mass. Specimens were tested for orthodontic bracket shear bond strength (SBS) to enamel, Ca and P ion initial release, recharge and re-release. The new orthodontic cement exhibited an SBS similar to commercial orthodontic cement without CaP release (P>0.1). Specimens after one recharge treatment (e.g., 1 min immersion in recharge solution repeating three times in one day, referred to as “1 min 3 times”) exhibited a substantial and continuous re-release of Ca and P ions for 14 days without further recharge. The ion re-release did not decrease with increasing the number of recharge/re-release cycles (P>0.1). The ion re-release concentrations at 14 days versus various recharge treatments were as follows: 1 min 3 times>3 min 2 times>1 min 2 times>6 min 1 time>3 min 1 time>1 min 1 time. In conclusion, although previous studies have shown that NACP nanocomposite remineralized tooth lesions and inhibited caries, the present study developed the first orthodontic cement with Ca and P ion recharge and long-term release capability. This NACP-rechargeable orthodontic cement is a promising therapy to inhibit enamel demineralization and WSLs around orthodontic brackets. PMID:27811847

Novel rechargeable calcium phosphate nanoparticle-containing orthodontic cement.

PubMed

Xie, Xian-Ju; Xing, Dan; Wang, Lin; Zhou, Han; Weir, Michael D; Bai, Yu-Xing; Xu, Hockin Hk

2017-03-01

White spot lesions (WSLs), due to enamel demineralization, occur frequently in orthodontic treatment. We recently developed a novel rechargeable dental composite containing nanoparticles of amorphous calcium phosphate (NACP) with long-term calcium (Ca) and phosphate (P) ion release and caries-inhibiting capability. The objectives of this study were to develop the first NACP-rechargeable orthodontic cement and investigate the effects of recharge duration and frequency on the efficacy of ion re-release. The rechargeable cement consisted of pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA). NACP was mixed into the resin at 40% by mass. Specimens were tested for orthodontic bracket shear bond strength (SBS) to enamel, Ca and P ion initial release, recharge and re-release. The new orthodontic cement exhibited an SBS similar to commercial orthodontic cement without CaP release (P>0.1). Specimens after one recharge treatment (e.g., 1 min immersion in recharge solution repeating three times in one day, referred to as "1 min 3 times") exhibited a substantial and continuous re-release of Ca and P ions for 14 days without further recharge. The ion re-release did not decrease with increasing the number of recharge/re-release cycles (P>0.1). The ion re-release concentrations at 14 days versus various recharge treatments were as follows: 1 min 3 times>3 min 2 times>1 min 2 times>6 min 1 time>3 min 1 time>1 min 1 time. In conclusion, although previous studies have shown that NACP nanocomposite remineralized tooth lesions and inhibited caries, the present study developed the first orthodontic cement with Ca and P ion recharge and long-term release capability. This NACP-rechargeable orthodontic cement is a promising therapy to inhibit enamel demineralization and WSLs around orthodontic brackets.

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.

Estimating the proportion of groundwater recharge from flood events in relation to total annual recharge in a karst aquifer

NASA Astrophysics Data System (ADS)

Dvory, N. Z.; Ronen, A.; Livshitz, Y.; Adar, E.; Kuznetsov, M.; Yakirevich, A.

2017-12-01

Sustainable groundwater production from karstic aquifers is primarily dictated by its recharge rate. Therefore, in order to limit over-exploitation, it is essential to accurately quantify groundwater recharge. Infiltration during erratic floods in karstic basins may contribute substantial amount to aquifer recharge. However, the complicated nature of karst systems, which are characterized in part by multiple springs, sinkholes, and losing/gaining streams, present a large obstacle to accurately assess the actual contribution of flood water to groundwater recharge. In this study, we aim to quantify the proportion of groundwater recharge during flood events in relation to the annual recharge for karst aquifers. The role of karst conduits on flash flood infiltration was examined during four flood and artificial runoff events in the Sorek creek near Jerusalem, Israel. The events were monitored in short time steps (four minutes). This high resolution analysis is essential to accurately estimating surface flow volumes, which are of particular importance in arid and semi-arid climate where ephemeral flows may provide a substantial contribution to the groundwater reservoirs. For the present investigation, we distinguished between direct infiltration, percolation through karst conduits and diffused infiltration, which is most affected by evapotranspiration. A water balance was then calculated for the 2014/15 hydrologic year using the Hydrologic Engineering Center - Hydrologic Modelling System (HEC-HMS). Simulations show that an additional 8% to 24% of the annual recharge volume is added from runoff losses along the creek that infiltrate through the karst system into the aquifer. The results improve the understanding of recharge processes and support the use of the proposed methodology for quantifying groundwater recharge.

Paleomagnetic and AMS study of Permian and Triassic rocks from the Hronic Nappe and Paleogene rocks from the Central Carpathian Paleogene Basin, Western Carpathians

NASA Astrophysics Data System (ADS)

Márton, Emö; Madzin, Jozef; Bučová, Jana; Grabowski, Jacek; Plašienka, Dušan; Aubrecht, Roman

2017-04-01

The Hronic (Choč) units form the highest cover nappe system of the Central Western Carpathians which was emplaced over the Fatric (Krížna) nappe system during the Late Cretaceous. The Permian (red beds and lava flows) and Triassic (sediments) rocks, the main targets of our study, were affected only by diagenetic or very low-grade, burial-related recrystallization and were tilted and transported together. The pre-late Cretaceous sequence is overlapped by Paleogene mainly flysch sequences. Three laboratories (Bratislava, Budapest and Warsaw) were involved in standard paleomagnetic processing and AMS measurements of the samples, while Curie-points were determined in Budapest. The site/locality mean paleomagnetic directions obtained were significantly different from the local direction of the present Earth magnetic field, indicating the long term stability of the paleomagnetic signal. The magnetic fabrics varied from un-oriented to dominantly schistose with well-defined lineations. The latter were normally subhorizontal, although subvertical maxima also occurred among the Triassic sediments. Shallow inclinations, after tilt corrections, suggest near-equatorial position for most of the Permian and Lower Triassic, while around 20°N for the Middle-Upper Triassic localities. The paleomagnetic declinations are interpreted in terms of CW tectonic rotations, which are normally larger for the Permian than for the Triassic samples, although there are some differences within the same age groups. This may be attributed to differential movements during nappe emplacement or subsequent tectonic disturbances. For two localities from the Paleogene cover sequence of the Hronic units, close to the main sampling area (Low Tatra Mts) of the present study documented fairly large CCW rotations, thus obtained additional evidence for the general CCW rotation of the Central Western Carpathians during the Cenozoic. Thus, we conclude that the Cenozoic CCW rotation was pre-dated by large CW

Impacts of afforestation on groundwater resources and quality

NASA Astrophysics Data System (ADS)

Allen, Alistair; Chapman, Deborah

2001-07-01

que des pratiques forestières non coordonnées sont susceptibles d'exacerber les crues. La recharge des nappes est affectée par la foresterie, surtout à cause de prélèvements plus importants de l'eau du sol par les arbres et à cause de la capacité accrue des sols forestiers à retenir de l'eau, conduisant à de plus fortes teneurs en matières organiques. Les taux de recharge sous les forêts peuvent être réduits d'un dixième par rapport à la prairie ou à la lande. La qualité de l'eau souterraine peut être affectée par une acidification accrue et par une nitrification sous les forêts, provoquées pour une part par une fixation des polluants atmosphériques par le couvert forestier et pour une autre part par un dépôt plus important d'une litière plus fortement acide. Les taux de recharge plus lente des nappes sous les forêts conduisent à des retards importants dans la manifestation de la détérioration de la qualité de l'eau souterraine. Resumen. Se han iniciado los planes para duplicar la proporción de terrenos reforestados en Irlanda hacia el año 2035. El plan, impulsado por fines económicos, ignora los impactos potenciales medioambientales de la silvicultura, y, en particular, los impactos a los recursos de aguas subterráneas y a su calidad. Puesto que el 25 % del agua potable en Irlanda es suministrada por medio de aguas subterráneas, dichos impactos son importantes. Las investigaciones de campo indican que la reforestación lleva a una reducción de la escorrentía de hasta un 20 %, fundamentalmente por la interceptación de la lluvia en las copas de los árboles, mientras que la deforestación tiene el impacto opuesto. Las implicaciones son tales que las prácticas forestales descoordinadas pueden aumentar enormemente el riesgo de inundaciones. También la recarga a los acuíferos se ve afectada por la reforestación, debido, sobre todo, al uso del agua del suelo por los árboles y a la mayor capacidad de retención de los suelos en

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.

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…

Recycling of used Ni-MH rechargeable batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Metamorphic sole genesis at the base of ophiolite nappes: Insights from numerical models

NASA Astrophysics Data System (ADS)

Yamato, Philippe; Agard, Philippe; Duretz, Thibault

2015-04-01

Obduction emplaces oceanic lithosphere on top of continental lithosphere. Although a number of studies have focused on this enigmatic process, the initial stages of obduction remain poorly understood. Field, petrological, and geochronological data reveal that during the first stages of the obduction (i.e., during the first 1-2 Myrs) a HT-LP metamorphic sole (~700-800 ° C and ~1 GPa) is systematically welded at the base of ophiolite nappes. However, the reason why such welding of the ophiolite soles occurs at these particular P-T conditions, and only at the onset of obduction, is still an open issue. The aim of this study is to explore the conditions required to explain the genesis of metamorphic soles. For this, we employ two-dimensional numerical modelling, constrained by the wealth of available data from the Oman ophiolite. We first present a thermo-kinematic model in which the velocity field is prescribed in order to simulate obduction initiation. The heat advection-diffusion equation is solved at each time step. The model is intentionally kept simple in order to control each parameter (e.g., convergence rate, dip angle, thermal age) and to test its influence on the resulting P-T conditions obtained through time along the obduction interface. Results show that the key factor allowing the formation of metamorphic soles is the age of the oceanic lithosphere involved. Moreover, we speculate that the reason why metamorphic soles are always welded at the same P-T conditions is due to the fact that, at these particular conditions, strength jumps occur within the oceanic lithosphere. These jumps lead to changes in strain localisation and allow the spalling of oceanic crust and its juxtaposition to the ophiolite nappe. This hypothesis is further tested using thermo-mechanical models in which the obduction initiates dynamically (only initial and boundary conditions are prescribed). The interplay between the temperature evolution and the mechanical behaviour is then

Simulation of regional-scale groundwater flow in the Azul River basin, Buenos Aires Province, Argentina

NASA Astrophysics Data System (ADS)

Varni, Marcelo R.; Usunoff, Eduardo J.

A three-dimensional modular model (MODFLOW) was used to simulate groundwater flow in the Azul River basin, Buenos Aires Province, Argentina, in order to assess the correctness of the conceptual model of the hydrogeological system. Simulated heads satisfactorily match observed heads in the regional water-table aquifer. Model results indicate that: (1) groundwater recharge is not uniform throughout the region but is best represented by three recharge rates, decreasing downgradient, similar to the distribution of soils and geomorphological characteristics; and (2) evapotranspiration rates are larger than previous estimates, which were made by using the Thornthwaite-Mather method. Evapotranspiration rates estimated by MODFLOW agree with results of independent studies of the region. Model results closely match historical surface-flow records, thereby suggesting that the model description of the aquifer-river relationship is correct. Résumé Un modèle modulaire tridimensionnel (MODFLOW) a été utilisé pour simuler les écoulements souterrains dans le bassin de la rivière Azul (Province de Buenos Aires, Argentine), dans le but d'évaluer la justesse du modèle conceptuel du système hydrogéologique. La piézométrie simulée s'ajuste de façon satisfaisante à celle observée pour l'ensemble de la nappe. Les résultats du modèle indiquent que: (1) la recharge de la nappe n'est pas uniforme sur toute la région, mais qu'elle est mieux approchée par trois valeurs différentes, décroissant vers l'aval-gradient, en suivant la même distribution que les sols et les caractéristiques géomorphologiques et (2) l'évapotranspiration est nettement plus importante que prévu initialement à partir de la méthode de Thornthwaite-Mather. Les valeurs d'évapotranspiration fournies par MODFLOW concordent bien avec les résultats d'autres études portant sur la région. Les résultats du modèle reproduisent convenablement les chroniques de débit des écoulements de surface

Proposed artificial recharge studies in northern Qatar

USGS Publications Warehouse

Kimrey, J.O.

1985-01-01

The aquifer system in northern Qatar comprises a water-table aquifer in the Rus Formation which is separated by an aquitard from a partially confined aquifer in the top of the overlying Umm er Radhuma Formation. These two aquifers are composed of limestone and dolomite of Eocene and Paleocene age and contain a fragile lens of freshwater which is heavily exploited as a source of water for agricultural irrigation. Net withdrawals are greatly in excess of total recharge, and quality of ground water is declining. Use of desalinated seawater for artificial recharge has been proposed for the area. Artificial recharge, on a large scale, could stabilize the decline in ground-water quality while allowing increased withdrawals for irrigation. The proposal appears technically feasible. Recharge should be by injection to the Umm er Radhuma aquifer whose average transmissivity is about 2,000 meters squared per day (as compared to an average of about 200 meters squared per day for the Rus aquifer). Implementation of artificial recharge should be preceded by a hydrogeologic appraisal. These studies should include test drilling, conventional aquifer tests, and recharge-recovery tests at four sites in northern Qatar. (USGS)

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

Alterations to groundwater recharge due to anthropogenic landscape change

NASA Astrophysics Data System (ADS)

Han, Dongmei; Currell, Matthew J.; Cao, Guoliang; Hall, Benjamin

2017-11-01

The impacts of anthropogenic modifications to the landscape on groundwater recharge rates, locations, and mechanisms are reviewed. The two major categories of change examined are conversion of land for agriculture and urbanization, both of which have significant effects on groundwater recharge. Techniques for identifying and quantifying the changes in recharge due to these impacts are discussed. Land-clearing for agriculture and surface water transfer for irrigation have resulted in order of magnitude increases in recharge rates in many semi-arid regions worldwide, causing ongoing land and water salinization and water-logging problems. While increased recharge by irrigation return flow may alleviate shallow groundwater depletion in some settings, this is complicated by the effect of unsaturated zone thickening, which reduces the fraction of potential recharge becoming actual recharge, and may result in new water quality risks such as nitrate contamination. Expansion of urban and peri-urban land and their associated surface and sub-surface infrastructure results in complex water balance changes that re-distribute groundwater recharge locations, modify recharge mechanism(s) and result in variable impacts on recharge rates (e.g., overall net decrease, increase or minimal change) and quality. While changes to groundwater recharge resulting from conversion of land for agriculture are relatively well understood, less is documented about the changes resulting from urbanization, due to a paucity of data from field-based studies. Two case studies from Beijing, China and Melbourne Australia are examined, which highlight these impacts and demonstrate some potential methodological techniques for this topic.

Late Maastrichtian foraminiferids and diatoms from the Polish Carpathians (Ropianka Formation, Skole Nappe): a case study from the Chmielnik-Grabówka composite section

NASA Astrophysics Data System (ADS)

Gasiński, M. Adam; Olshtynska, Alexandra; Uchman, Alfred

2013-12-01

Gasiński, M.A., Olshtynska, A. and Uchman, A. 2013. Late Maastrichtian foraminiferids and diatoms from the Polish Carpathians (Ropianka Formation, Skole Nappe): a case study from the Chmielnik-Grabowka composite section. Acta Geologica Polonica, 63(4), 515-525. Warszawa. Well-preserved foraminiferids have been found in the Chmielnik-Grabowka section (Skole Nappe, Polish Carpathians). The Abathomphalus mayaroensis (late Maastrichtian) and Racemiguembelina fructicosa (earlylate Maastrichtian) standard planktonic foraminiferal biozones have been recognized, based on the occurrence of their respective index species. Sediments of the R. fructicosa Zone contain diatoms, which are a rare component of Cretaceous flysch microfossil assemblages in the Carpathians. The diatom frustules and some foraminiferid tests are pyritized, probably after burial in the sediment, below the redox boundary or in the oxygen- deficient microenvironment inside the frustules or tests of microfossils; the presence of trace fossils and bioturbational structures in the same bed indicate an oxygenated sea floor.

NORTH CAROLINA GROUNDWATER RECHARGE RATES 1994

EPA Science Inventory

North Carolina Groundwater Recharge Rates, from Heath, R.C., 1994, Ground-water recharge in North Carolina: North Carolina State University, as prepared for the NC Department of Environment, Health and Natural Resources (NC DEHNR) Division of Enviromental Management Groundwater S...

Groundwater recharge: The intersection between humanity and hydrogeology

NASA Astrophysics Data System (ADS)

Smerdon, Brian D.; Drewes, Jörg E.

2017-12-01

Groundwater recharge is an essential part of subsurface water circulation and the beginning of groundwater flow systems that can vary in duration from days to millennia. Globally, there is a growing body of evidence suggesting that many of Earth's aquifers contain 'fossil' groundwater that was recharged more than 12,000 years ago (Jasechko et al., 2017), and a very small portion of groundwater that was recharged within the last 50 years (Gleeson et al., 2015). Together, this information demonstrates the irregular distribution of groundwater circulation within the Earth and the wide variability of recharge conditions that replenish aquifer systems (Befus et al., 2017). Knowledge of groundwater recharge rates and distribution are needed for evaluating and regulating the quantity and quality of water resources, understanding consequences of landscapes use, identifying where managed aquifer recharge can augment supply, and predicting how groundwater systems will respond to a changing climate. In-turn, these topics are of central importance for the health of humans and ecosystems, and security of food and energy. Yet, despite the global importance, quantifying groundwater recharge remains challenging as it cannot be measured directly, and there is uncertainty associated with all currently known estimation methods (Scanlon et al., 2002).

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.

Recharge signal identification based on groundwater level observations.

PubMed

Yu, Hwa-Lung; Chu, Hone-Jay

2012-10-01

This study applied a method of the rotated empirical orthogonal functions to directly decompose the space-time groundwater level variations and determine the potential recharge zones by investigating the correlation between the identified groundwater signals and the observed local rainfall records. The approach is used to analyze the spatiotemporal process of piezometric heads estimated by Bayesian maximum entropy method from monthly observations of 45 wells in 1999-2007 located in the Pingtung Plain of Taiwan. From the results, the primary potential recharge area is located at the proximal fan areas where the recharge process accounts for 88% of the spatiotemporal variations of piezometric heads in the study area. The decomposition of groundwater levels associated with rainfall can provide information on the recharge process since rainfall is an important contributor to groundwater recharge in semi-arid regions. Correlation analysis shows that the identified recharge closely associates with the temporal variation of the local precipitation with a delay of 1-2 months in the study area.

Consistent Top-to-the-foreland Directed Deformation from Floor to Roof in the Seve Nappe Complex (SNC), Jämtland, Sweden

NASA Astrophysics Data System (ADS)

Bender, H.; Ring, U.; Almqvist, B. S. G.; Glodny, J.; Grasemann, B.; Stephens, M. B.

2016-12-01

The recent COSC-1 drilling programme (Lorenz et al., 2015), discovery of microdiamonds (Majka et al., 2014) and discussion of extrusion-wedge tectonics (Grimmer et al., 2015) outline the importance of the Seve Nappe Complex (SNC) and its key role during the Caledonian orogeny. The kinematic evolution of the SNC is crucial for better understanding the entire mountain belt. Thorough structural mapping of the SNC and adjacent units was conducted in western and northern Jämtland, central Sweden. Complementary microstructural investigations strengthen the field observations and show consistent top-to-the-SE directed movement through all studied tectonic units. Amphibolite-facies deformation can be inferred from fabrics in the SNC, which are overprinted by greenschist-facies structures showing the same kinematics throughout the studied section of the nappe stack. These data indicate persistence of the same foreland-directed kinematics over a wide range of pressure-temperature conditions in space and time. Currently proposed models for exhuming high-grade metamorphic rocks in collisional orogens fail to explain these observations and highlight the need for discussing new tectonic concepts for the Scandinavian Caledonides. References: Grimmer et al., 2015, Geology 43 (4); Lorenz et al., 2015, Scientific Drilling 19; Majka et al. 2014, Geology 42 (12).

Estimated infiltration, percolation, and recharge rates at the Rillito Creek focused recharge investigation site, Pima County, Arizona: Chapter H in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

USGS Publications Warehouse

Hoffmann, John P.; Blasch, Kyle W.; Pool, Don R.; Bailey, Matthew A.; Callegary, James B.; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

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

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

Global synthesis of groundwater recharge in semiarid and arid regions

USGS Publications Warehouse

Scanlon, Bridget 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 (40–374 000 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

Programming settings and recharge interval in a prospective study of a rechargeable sacral neuromodulation system for the treatment of overactive bladder.

PubMed

Blok, Bertil; Van Kerrebroeck, Philip; de Wachter, Stefan; Ruffion, Alain; Van der Aa, Frank; Jairam, Ranjana; Perrouin-Verbe, Marie; Elneil, Sohier

2018-02-01

The RELAX-OAB study is designed to confirm the safety, efficacy, and technical performance of the Axonics r-SNM System, a miniaturized, rechargeable SNM system approved in Europe and Canada for the treatment of bladder and bowel dysfunction. The purpose of this article is to describe study subjects' ability to charge the rechargeable neurostimulator and to document their neurostimulator program settings and recharge interval over time. Fifty-one OAB patients were implanted in a single-stage procedure. These results represent the 3-month charging experience for 48 subjects who completed the 3-month follow-up. Recharge intervals were estimated using therapy stimulation settings and subject experience was evaluated using questionnaires. Forty-seven of forty-eight (98%) subjects were able to successfully charge their device prior to follow-up within 1-month post-implant. At 3-month post-implant, 98% of subjects were able to charge prior to their follow-up visit. Average stimulation amplitude across all subjects was 1.8 mA (±1.1 mA). A total of 69% of subjects had ≥14-day recharge intervals (time between charging) and 98% of subjects had ≥7-day recharge interval. No charging related adverse events occurred. Study subjects were able to charge the Axonics r-SNM System and stimulation settings provided 2 weeks of therapy between recharging for most subjects. Subject satisfaction indicates that subjects are satisfied with rechargeable SNM therapy. © 2018 The Authors. Neurourology and Urodynamics Published by Wiley Periodicals, Inc.

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).

High power rechargeable magnesium/iodine battery chemistry

DOE PAGES

Tian, Huajun; Gao, Tao; Li, Xiaogang; ...

2017-01-10

Rechargeable magnesium batteries have attracted considerable attention because of their potential high energy density and low cost. However, their development has been severely hindered because of the lack of appropriate cathode materials. Here we report a rechargeable magnesium/iodine battery, in which the soluble iodine reacts with Mg 2+ to form a soluble intermediate and then an insoluble final product magnesium iodide. The liquid–solid two-phase reaction pathway circumvents solid-state Mg 2+ diffusion and ensures a large interfacial reaction area, leading to fast reaction kinetics and high reaction reversibility. As a result, the rechargeable magnesium/iodine battery shows a better rate capability (180more » mAh g –1 at 0.5 C and 140 mAh g –1 at 1 C) and a higher energy density (~400 Wh kg –1) than all other reported rechargeable magnesium batteries using intercalation cathodes. As a result, this study demonstrates that the liquid–solid two-phase reaction mechanism is promising in addressing the kinetic limitation of rechargeable magnesium batteries.« less

Global-scale modeling of groundwater recharge

NASA Astrophysics Data System (ADS)

Döll, P.; Fiedler, K.

2008-05-01

Long-term average groundwater recharge, which is equivalent to renewable groundwater resources, is the major limiting factor for the sustainable use of groundwater. Compared to surface water resources, groundwater resources are more protected from pollution, and their use is less restricted by seasonal and inter-annual flow variations. To support water management in a globalized world, it is necessary to estimate groundwater recharge at the global scale. Here, we present a best estimate of global-scale long-term average diffuse groundwater recharge (i.e. renewable groundwater resources) that has been calculated by the most recent version of the WaterGAP Global Hydrology Model WGHM (spatial resolution of 0.5° by 0.5°, daily time steps). The estimate was obtained using two state-of-the-art global data sets of gridded observed precipitation that we corrected for measurement errors, which also allowed to quantify the uncertainty due to these equally uncertain data sets. The standard WGHM groundwater recharge algorithm was modified for semi-arid and arid regions, based on independent estimates of diffuse groundwater recharge, which lead to an unbiased estimation of groundwater recharge in these regions. WGHM was tuned against observed long-term average river discharge at 1235 gauging stations by adjusting, individually for each basin, the partitioning of precipitation into evapotranspiration and total runoff. We estimate that global groundwater recharge was 12 666 km3/yr for the climate normal 1961-1990, i.e. 32% of total renewable water resources. In semi-arid and arid regions, mountainous regions, permafrost regions and in the Asian Monsoon region, groundwater recharge accounts for a lower fraction of total runoff, which makes these regions particularly vulnerable to seasonal and inter-annual precipitation variability and water pollution. Average per-capita renewable groundwater resources of countries vary between 8 m3/(capita yr) for Egypt to more than 1 million m3

Global-scale modeling of groundwater recharge

NASA Astrophysics Data System (ADS)

Döll, P.; Fiedler, K.

2007-11-01

Long-term average groundwater recharge, which is equivalent to renewable groundwater resources, is the major limiting factor for the sustainable use of groundwater. Compared to surface water resources, groundwater resources are more protected from pollution, and their use is less restricted by seasonal and inter-annual flow variations. To support water management in a globalized world, it is necessary to estimate groundwater recharge at the global scale. Here, we present a best estimate of global-scale long-term average diffuse groundwater recharge (i.e. renewable groundwater resources) that has been calculated by the most recent version of the WaterGAP Global Hydrology Model WGHM (spatial resolution of 0.5° by 0.5°, daily time steps). The estimate was obtained using two state-of-the art global data sets of gridded observed precipitation that we corrected for measurement errors, which also allowed to quantify the uncertainty due to these equally uncertain data sets. The standard WGHM groundwater recharge algorithm was modified for semi-arid and arid regions, based on independent estimates of diffuse groundwater recharge, which lead to an unbiased estimation of groundwater recharge in these regions. WGHM was tuned against observed long-term average river discharge at 1235 gauging stations by adjusting, individually for each basin, the partitioning of precipitation into evapotranspiration and total runoff. We estimate that global groundwater recharge was 12 666 km3/yr for the climate normal 1961-1990, i.e. 32% of total renewable water resources. In semi-arid and arid regions, mountainous regions, permafrost regions and in the Asian Monsoon region, groundwater recharge accounts for a lower fraction of total runoff, which makes these regions particularly vulnerable to seasonal and inter-annual precipitation variability and water pollution. Average per-capita renewable groundwater resources of countries vary between 8 m3/(capita yr) for Egypt to more than 1 million m3

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

Modeling Recharge - can it be Done?

NASA Astrophysics Data System (ADS)

Verburg, K.; Bond, W. J.; Smith, C. J.; Dunin, F. X.

2001-12-01

In sub-humid areas where rainfall is relatively low and sporadic, recharge (defined as water movement beyond the active root zone) is the small difference between the much larger numbers rainfall and evapotranspiration. It is very difficult to measure and often modeling is resorted to instead. But is modeling this small number any less difficult than measurement? In Australia there is considerable debate over the magnitude of recharge under different agricultural systems because of its contribution to rising saline groundwater levels following the clearing of native vegetation in the last 100 years. Hence the adequacy of measured and modeled estimates of recharge is under close scrutiny. Results will be presented for the water balance of an intensively monitored 8 year sequence of crops and pastures. Measurements included meteorological inputs, evapotranspiration measured with a pair of weighing lysimeters, and soil water content was measured with TDR and neutron moisture meter. Recharge was estimated from the percolate removed from the lysimeters as well as, when conditions were suitable, from soil water measurements and combined soil water and evapotranspiration measurements. This data was simulated using a comprehensive soil-plant-atmosphere model (APSIM). Comparison with field measurements shows that the recharge can be simulated with an accuracy similar to that with which it can be measured. However, is either sufficiently accurate for the applications for which they are required?

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)

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.

An Efficient Wireless Recharging Mechanism for Achieving Perpetual Lifetime of Wireless Sensor Networks

PubMed Central

Yu, Hongli; Chen, Guilin; Zhao, Shenghui; Chang, Chih-Yung; Chin, Yu-Ting

2016-01-01

Energy recharging has received much attention in recent years. Several recharging mechanisms were proposed for achieving perpetual lifetime of a given Wireless Sensor Network (WSN). However, most of them require a mobile recharger to visit each sensor and then perform the recharging task, which increases the length of the recharging path. Another common weakness of these works is the requirement for the mobile recharger to stop at the location of each sensor. As a result, it is impossible for recharger to move with a constant speed, leading to inefficient movement. To improve the recharging efficiency, this paper takes “recharging while moving” into consideration when constructing the recharging path. We propose a Recharging Path Construction (RPC) mechanism, which enables the mobile recharger to recharge all sensors using a constant speed, aiming to minimize the length of recharging path and improve the recharging efficiency while achieving the requirement of perpetual network lifetime of a given WSN. Performance studies reveal that the proposed RPC outperforms existing proposals in terms of path length and energy utilization index, as well as visiting cycle. PMID:28025567

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

Strain partitioning in the footwall of the Somiedo Nappe: structural evolution of the Narcea Tectonic Window, NW Spain

NASA Astrophysics Data System (ADS)

Gutiérrez-Alonso, Gabriel

1996-10-01

The Somiedo Nappe is a major thrust unit in the Cantabrian Zone, the external foreland fold and thrust belt of the North Iberian Variscan orogen. Exposed at the Narcea Tectonic Window are Precambrian rocks below the basal decollement of the Somiedo Nappe, which exhibit a different deformation style than the overlying Paleozoic rocks above the basal decollement. During Variscan deformation, folding and widespread subhorizontal, bedding-parallel decollements were produced in the hanging wall within the Paleozoic rocks. Vertical folding, with related axial-planar cleavage at a high angle to the decollement planes, developed simultaneously in the upper Proterozoic Narcea Slates of the footwall, below the detachment. The relative magnitude of finite strain, measured in the footwall rocks, diminishes towards the foreland. These observations indicate that (1) significant deformation may occur in the footwall of foreland fold and thrust belts, (2) the shortening mechanism in the footwall may be different from that of the hanging wall, and (3) in this particular case, the partitioning of the deformation implies the existence of a deeper, blind decollement surface contemporaneous with the first stages of the foreland development, that does not crop out in the region. This implies a significant shortening in the footwall, which must be taken into account when restoration and balancing of cross-sections is attempted. A sequential diagram of the evolution of the Narcea Tectonic Window with a minimum shortening of 85 km is proposed, explaining the complete Variscan evolution of the foreland to hinterland transition in the North Iberian Variscan orogen.

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.

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.

Can we calibrate simultaneously groundwater recharge and aquifer hydrodynamic parameters ?

NASA Astrophysics Data System (ADS)

Hassane Maina, Fadji; Ackerer, Philippe; Bildstein, Olivier

2017-04-01

By groundwater model calibration, we consider here fitting the measured piezometric heads by estimating the hydrodynamic parameters (storage term and hydraulic conductivity) and the recharge. It is traditionally recommended to avoid simultaneous calibration of groundwater recharge and flow parameters because of correlation between recharge and the flow parameters. From a physical point of view, little recharge associated with low hydraulic conductivity can provide very similar piezometric changes than higher recharge and higher hydraulic conductivity. If this correlation is true under steady state conditions, we assume that this correlation is much weaker under transient conditions because recharge varies in time and the parameters do not. Moreover, the recharge is negligible during summer time for many climatic conditions due to reduced precipitation, increased evaporation and transpiration by vegetation cover. We analyze our hypothesis through global sensitivity analysis (GSA) in conjunction with the polynomial chaos expansion (PCE) methodology. We perform GSA by calculating the Sobol indices, which provide a variance-based 'measure' of the effects of uncertain parameters (storage and hydraulic conductivity) and recharge on the piezometric heads computed by the flow model. The choice of PCE has the following two benefits: (i) it provides the global sensitivity indices in a straightforward manner, and (ii) PCE can serve as a surrogate model for the calibration of parameters. The coefficients of the PCE are computed by probabilistic collocation. We perform the GSA on simplified real conditions coming from an already built groundwater model dedicated to a subdomain of the Upper-Rhine aquifer (geometry, boundary conditions, climatic data). GSA shows that the simultaneous calibration of recharge and flow parameters is possible if the calibration is performed over at least one year. It provides also the valuable information of the sensitivity versus time, depending on

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

Ophiolitic detritus in Kimmeridgian resedimented limestones and its provenance from an eroded obducted ophiolitic nappe stack south of the Northern Calcareous Alps (Austria)

NASA Astrophysics Data System (ADS)

Gawlick, Hans-Jürgen; Aubrecht, Roman; Schlagintweit, Felix; Missoni, Sigrid; Plašienka, Dušan

2015-12-01

The causes for the Middle to Late Jurassic tectonic processes in the Northern Calcareous Alps are still controversially discussed. There are several contrasting models for these processes, formerly designated "Jurassic gravitational tectonics". Whereas in the Dinarides or the Western Carpathians Jurassic ophiolite obduction and a Jurassic mountain building process with nappe thrusting is widely accepted, equivalent processes are still questioned for the Eastern Alps. For the Northern Calcareous Alps, an Early Cretaceous nappe thrusting process is widely favoured instead of a Jurassic one, obviously all other Jurassic features are nearly identical in the Northern Calcareous Alps, the Western Carpathians and the Dinarides. In contrast, the Jurassic basin evolutionary processes, as best documented in the Northern Calcareous Alps, were in recent times adopted to explain the Jurassic tectonic processes in the Carpathians and Dinarides. Whereas in the Western Carpathians Neotethys oceanic material is incorporated in the mélanges and in the Dinarides huge ophiolite nappes are preserved above the Jurassic basin fills and mélanges, Jurassic ophiolites or ophiolitic remains are not clearly documented in the Northern Calcareous Alps. Here we present chrome spinel analyses of ophiolitic detritic material from Kimmeridgian allodapic limestones in the central Northern Calcareous Alps. The Kimmeridgian age is proven by the occurrence of the benthic foraminifera Protopeneroplis striata and Labyrinthina mirabilis, the dasycladalean algae Salpingoporella pygmea, and the alga incertae sedis Pseudolithocodium carpathicum. From the geochemical composition the analysed spinels are pleonastes and show a dominance of Al-chromites (Fe3+-Cr3+-Al3+ diagram). In the Mg/(Mg+ Fe2+) vs. Cr/(Cr+ Al) diagram they can be classified as type II ophiolites and in the TiO2 vs. Al2O3 diagram they plot into the SSZ peridotite field. All together this points to a harzburgite provenance of the analysed

Emulation of recharge and evapotranspiration processes in shallow groundwater systems

NASA Astrophysics Data System (ADS)

Doble, Rebecca C.; Pickett, Trevor; Crosbie, Russell S.; Morgan, Leanne K.; Turnadge, Chris; Davies, Phil J.

2017-12-01

In shallow groundwater systems, recharge and evapotranspiration are highly sensitive to changes in the depth to water table. To effectively model these fluxes, complex functions that include soil and vegetation properties are often required. Model emulation (surrogate modelling or meta-modelling) can provide a means of incorporating detailed conceptualisation of recharge and evapotranspiration processes, while maintaining the numerical tractability and computational performance required for regional scale groundwater models and uncertainty analysis. A method for emulating recharge and evapotranspiration processes in groundwater flow models was developed, and applied to the South East region of South Australia and western Victoria, which is characterised by shallow groundwater, wetlands and coastal lakes. The soil-vegetation-atmosphere transfer (SVAT) model WAVES was used to generate relationships between net recharge (diffuse recharge minus evapotranspiration from groundwater) and depth to water table for different combinations of climate, soil and land cover types. These relationships, which mimicked previously described soil, vegetation and groundwater behaviour, were combined into a net recharge lookup table. The segmented evapotranspiration package in MODFLOW was adapted to select values of net recharge from the lookup table depending on groundwater depth, and the climate, soil and land use characteristics of each cell. The model was found to be numerically robust in steady state testing, had no major increase in run time, and would be more efficient than tightly-coupled modelling approaches. It made reasonable predictions of net recharge and groundwater head compared with remotely sensed estimates of net recharge and a standard MODFLOW comparison model. In particular, the method was better able to predict net recharge and groundwater head in areas with steep hydraulic gradients.

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.

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

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.

How Might Recharge Change Under Projected Climate Change in Western US?

NASA Astrophysics Data System (ADS)

Niraula, R.; Meixner, T.; Rodell, M.; Ajami, H.; Gochis, D. J.; Castro, C. L.

2015-12-01

Although ground water is a major source of water in the western US, little research has been done on the impacts of climate change on western groundwater storage and recharge. Here we assess the impact of projected changes in precipitation and temperature on groundwater recharge across the western US by dividing the domain into five major regions (viz. Northern Rockies and Plains, South, Southwest, Northwest and West). Hydrologic outputs from the Variable Infiltration Capacity (VIC) model based on Bias-Correction and Spatial Disaggregation (BCSD) Coupled Model Inter-comparison Project Phase 5 (CMIP5) climate projections from 11 Global Circulation Models (GCMs) for Representative Concentration pathway 6.0 (RCP 6.0) scenarios were selected for projecting changes in recharge. Projections are made for near future (2020-2050) and far future (2070-2100) relative to the historical period (1970-2000). Averaged over the domain, half of the GCMs caused VIC to increase recharge across the region while the remaining half resulted in decreased recharge for both the near (-10.1% to 5.8%) and far (-9.7% to 17%) future. A majority (9 out of 11 GCMs) of the VIC simulations projected increased recharge in the Northern Rockies and Plains for both the near and far future. A majority of the simulations agreed on reduced recharge in other regions for the near future. For the far future, a majority of the simulations agreed on decreased recharge in the South (9 out of 11 GCMs) and Southwest (7 out of 11 GCMs) regions. The change is projected to be largest for the South region which could see recharged reduced by as much as 50%. Changes in recharge in the Northwest region are predicted to be small (within 10% of historical recharge). Despite the large variability in projected recharge across the GCMs, recharge projections from this study will help water managers with long term water management planning.

Effects of environmental change on groundwater recharge in the Desert Southwest

USGS Publications Warehouse

Phillips, Fred M.; Walvoord, Michelle Ann; Small, Eric E.; Hogan, James F.; Phillips, Fred M.; Scanlon, Bridget R.

2004-01-01

Climate and other environmental conditions have varied in the past, and will almost certainly vary significantly in the near future. The response of groundwater recharge to changes in environmental conditions is thus a matter of active concem for water-resources management. The major mechanisms for this response of recharge are three-fold. First, changes in vegetation communities can shift the water balance at the base of the root zone, increasing or decreasing the amount of recharge. Second, variations in the amount of runoff can affect channel recharge. Finally, shifts in the seasonality of precipitation can strongly affect the fraction that is evapotranspired back into the atmosphere and thus affect the amount that becomes recharge. Increases in recharge (defined as the water flux across the water table) may in some cases significantly increase fluxes through regional aquifers, but in other cases, depending on the hydrogeology, may only result in increased streamflow or evapotranspiration within the recharge area. Basins with relatively low maximum elevations, deep water tables, thin soils, and highly permeable recharge areas experience the largest recharge response to increases in precipitation. The relatively well-known paleoenvironmental history of the American Southwest can be compared with various lines of evidence for changes in recharge. These lines of evidence include timing of speleothem formation, chloride profiles in thick vadose zones, changes in water table shown by subsurface calcite precipitation, and expanded groundwater discharge areas. This evidence indicates that the wettest periods of the past 25 ka, which were generally between 20 and 13 ka, were also periods of enhanced vadose zone fluxes and aquifer discharge. Climate-driven changes in recharge appear to have been substantially mediated through changes in vegetation. This evidence for strong recharge response to past environmental changes indicates that expected future climate and

California GAMA Special Study: Importance of River Water Recharge to Selected Groundwater Basins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Visser, Ate; Moran, Jean E.; Singleton, Michael J.

River recharge represents 63%, 86% and 46% of modern groundwater in the Mojave Desert, Owens Valley, and San Joaquin Valley, respectively. In pre-modern groundwater, river recharge represents a lower fraction: 36%, 46%, and 24% respectively. The importance of river water recharge in the San Joaquin valley has nearly doubled and is likely the result of a total increase of recharge of 40%, caused by river water irrigation return flows. This emphasizes the importance of recharge of river water via irrigation for renewal of groundwater resources. Mountain front recharge and local precipitation contribute to recharge of desert groundwater basins in partmore » as the result of geological features focusing scarce precipitation promoting infiltration. River water recharges groundwater systems under lower temperatures and with larger water table fluctuations than local precipitation recharge. Surface storage is limited in time and volume, as evidenced by cold river recharge temperatures resulting from fast recharge, compared to the large capacity for subsurface storage. Groundwater banking of seasonal surface water flows therefore appears to be a natural and promising method for increasing the resilience of water supply systems. The distinct isotopic and noble gas signatures of river water recharge, compared to local precipitation recharge, reflecting the source and mechanism of recharge, are valuable constraints for numerical flow models.« less

A water-budget model and estimates of groundwater recharge for Guam

USGS Publications Warehouse

Johnson, Adam G.

2012-01-01

On Guam, demand for groundwater tripled from the early 1970s to 2010. The demand for groundwater is anticipated to further increase in the near future because of population growth and a proposed military relocation to Guam. Uncertainty regarding the availability of groundwater resources to support the increased demand has prompted an investigation of groundwater recharge on Guam using the most current data and accepted methods. For this investigation, a daily water-budget model was developed and used to estimate mean recharge for various land-cover and rainfall conditions. Recharge was also estimated for part of the island using the chloride mass-balance method. Using the daily water-budget model, estimated mean annual recharge on Guam is 394.1 million gallons per day, which is 39 percent of mean annual rainfall (999.0 million gallons per day). Although minor in comparison to rainfall on the island, water inflows from water-main leakage, septic-system leachate, and stormwater runoff may be several times greater than rainfall at areas that receive these inflows. Recharge is highest in areas that are underlain by limestone, where recharge is typically between 40 and 60 percent of total water inflow. Recharge is relatively high in areas that receive stormwater runoff from storm-drain systems, but is relatively low in urbanized areas where stormwater runoff is routed to the ocean or to other areas. In most of the volcanic uplands in southern Guam where runoff is substantial, recharge is less than 30 percent of total water inflow. The water-budget model in this study differs from all previous water-budget investigations on Guam by directly accounting for canopy evaporation in forested areas, quantifying the evapotranspiration rate of each land-cover type, and accounting for evaporation from impervious areas. For the northern groundwater subbasins defined in Camp, Dresser & McKee Inc. (1982), mean annual baseline recharge computed in this study is 159.1 million gallons

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

PubMed

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

2015-01-01

We have developed a method to identify and quantify recharge episodes, along with their associated infiltration-related inputs, by a consistent, systematic procedure. Our algorithm partitions a time series of water levels into discrete recharge episodes and intervals of no episodic recharge. It correlates each recharge episode with a specific interval of rainfall, so storm characteristics such as intensity and duration can be associated with the amount of recharge that results. To be useful in humid climates, the algorithm evaluates the separability of events, so that those whose recharge cannot be associated with a single storm can be appropriately lumped together. Elements of this method that are subject to subjectivity in the application of hydrologic judgment are values of lag time, fluctuation tolerance, and master recession parameters. Because these are determined once for a given site, they do not contribute subjective influences affecting episode-to-episode comparisons. By centralizing the elements requiring scientific judgment, our method facilitates such comparisons by keeping the most subjective elements openly apparent, making it easy to maintain consistency. If applied to a period of data long enough to include recharge episodes with broadly diverse characteristics, the method has value for predicting how climatic alterations in the distribution of storm intensities and seasonal duration may affect recharge. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

John B. Goodenough, Cathode Materials, and Rechargeable Lithium-ion

Science.gov Websites

cathode materials for the lithium-ion rechargeable battery that is ubiquitous in today’s portable conductors has enabled realization of the rechargeable lithium-ion battery used in cellular telephones and Goodenough, the rechargeable lithium ion battery, and related research is available in electronic documents

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.

Comparing potential recharge estimates from three Land Surface Models across the Western US

PubMed Central

NIRAULA, REWATI; MEIXNER, THOMAS; AJAMI, HOORI; RODELL, MATTHEW; GOCHIS, DAVID; CASTRO, CHRISTOPHER L.

2018-01-01

Groundwater is a major source of water in the western US. However, there are limited recharge estimates available in this region due to the complexity of recharge processes and the challenge of direct observations. Land surface Models (LSMs) could be a valuable tool for estimating current recharge and projecting changes due to future climate change. In this study, simulations of three LSMs (Noah, Mosaic and VIC) obtained from the North American Land Data Assimilation System (NLDAS-2) are used to estimate potential recharge in the western US. Modeled recharge was compared with published recharge estimates for several aquifers in the region. Annual recharge to precipitation ratios across the study basins varied from 0.01–15% for Mosaic, 3.2–42% for Noah, and 6.7–31.8% for VIC simulations. Mosaic consistently underestimates recharge across all basins. Noah captures recharge reasonably well in wetter basins, but overestimates it in drier basins. VIC slightly overestimates recharge in drier basins and slightly underestimates it for wetter basins. While the average annual recharge values vary among the models, the models were consistent in identifying high and low recharge areas in the region. Models agree in seasonality of recharge occurring dominantly during the spring across the region. Overall, our results highlight that LSMs have the potential to capture the spatial and temporal patterns as well as seasonality of recharge at large scales. Therefore, LSMs (specifically VIC and Noah) can be used as a tool for estimating future recharge rates in data limited regions. PMID:29618845

Modeling Vegetation Growth Impact on Groundwater Recharge

NASA Astrophysics Data System (ADS)

Anurag, H.; Ng, G. H. C.; Tipping, R.

2017-12-01

Vegetation growth is affected by variability in climate and land-cover / land-use over a range of temporal and spatial scales. Vegetation also modifies water budget through interception and evapotranspiration and thus has a significant impact on groundwater recharge. Most groundwater recharge assessments represent vegetation using specified, static parameter, such as for leaf-area-index, but this neglects the effect of vegetation dynamics on recharge estimates. Our study addresses this gap by including vegetation growth in model simulations of recharge. We use NCAR's Community Land Model v4.5 with its BGC module (BGC is the new CLM4.5 biogeochemistry). It integrates prognostic vegetation growth with land-surface and subsurface hydrological processes and can thus capture the effect of vegetation on groundwater. A challenge, however, is the need to resolve uncertainties in model inputs ranging from vegetation growth parameters all the way down to the water table. We have compiled diverse data spanning meteorological inputs to subsurface geology and use these to implement ensemble model simulations to evaluate the possible effects of dynamic vegetation growth (versus specified, static vegetation parameterizations) on estimating groundwater recharge. We present preliminary results for select data-intensive test locations throughout the state of Minnesota (USA), which has a sharp east-west precipitation gradient that makes it an apt testbed for examining ecohydrologic relationships across different temperate climatic settings and ecosystems. Using the ensemble simulations, we examine the effect of seasonal to interannual variability of vegetation growth on recharge and water table depths, which has implications for predicting the combined impact of climate, vegetation, and geology on groundwater resources. Future work will include distributed model simulations over the entire state, as well as conditioning uncertain vegetation and subsurface parameters on remote sensing

Impacts of vegetation change on groundwater recharge

NASA Astrophysics Data System (ADS)

Bond, W. J.; Verburg, K.; Smith, C. J.

2003-12-01

Vegetation change is the accepted cause of increasing river salt concentrations and the salinisation of millions of hectares of farm land in Australia. Replacement of perennial native vegetation by annual crops and pastures following European settlement has altered the water balance causing increased groundwater recharge and mobilising the naturally saline groundwater. The Redesigning Agriculture for Australian Landscapes Program, of which the work described here is a part, was established to develop agricultural practices that are more attuned to the delicate water balance described above. Results of field measurements will be presented that contrast the water balance characteristics of native vegetation with those of conventional agricultural plants, and indicate the functional characteristics required of new agricultural practices to reduce recharge. New agricultural practices may comprise different management of current crops and pastures, or may involve introducing totally new species. In either case, long-term testing is required to examine their impact on recharge over a long enough climate record to encompass the natural variability of rainfall that is characteristic of most Australian farming regions. Field experimentation therefore needs to be complemented and extended by computer simulation. This requires a modelling approach that is more robust than conventional crop modelling because (a) it needs to be sensitive enough to predict small changes in the residual recharge term, (b) it needs to be able to simulate a variety of vegetation in different sequences, (c) it needs to be able to simulate continuously for several decades of input data, and (d) it therefore needs to be able to simulate the period between crops, which often has a critical impact on recharge. The APSIM simulation framework will be used to illustrate these issues and to explore the effect of different vegetation combinations on recharge.

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

Advances of aqueous rechargeable lithium-ion battery: A review

NASA Astrophysics Data System (ADS)

Alias, Nurhaswani; Mohamad, Ahmad Azmin

2015-01-01

The electrochemical characteristic of the aqueous rechargeable lithium-ion battery has been widely investigated in efforts to design a green and safe technology that can provide a highly specific capacity, high efficiency and long life for high power applications such as the smart grid and electric vehicle. It is believed that the advantages of this battery will overcome the limitations of the rechargeable lithium-ion battery with organic electrolytes that comprise safety and create high fabrication cost issues. This review focuses on the opportunities of the aqueous rechargeable lithium-ion battery compared to the conventional rechargeable lithium-ion battery with organic-based electrolytes. Previously reported studies are briefly summarised, together with the presentation of new findings based on the conductivity, morphology, electrochemical performance and cycling stability results. The factors that influence the electrochemical performance, the challenges and potential of the aqueous rechargeable lithium-ion battery are highlighted in order to understand and maintained the excellent battery performance.

Statistical Method for Identification of Potential Groundwater Recharge Zone

NASA Astrophysics Data System (ADS)

Banerjee, Pallavi; Singh, V. S.

2010-05-01

The effective development of groundwater resource is essential for a country like India. Artificial recharge is the planned, human activity of augmenting the amount of groundwater available through works designed to increase the natural replenishment or percolation of surface waters into the groundwater aquifers, resulting in a corresponding increase in the amount of groundwater available for abstraction. India receives good amount of average annual rainfall about 114 cm but most of it's part waste through runoff. The imbalance between rainfall and recharge has caused serious shortage of water for drinking, agriculture and industrial purposes. The over exploitation of groundwater due to increasing population is an additional cause of water crisis that resulting in reduction in per capita availability of water in the country. Thus the planning for effective development of groundwater is essential through artificial recharge. Objective of the paper is to identification of artificial recharge zones by arresting runoff through suitable sites to restore groundwater conditions using statistical technique. The water table variation follows a pattern similar to rainfall variation with time delay. The rainfall and its relationship with recharge is a very important process in a shallow aquifer system. Understanding of this process is of critical importance to management of groundwater resource in any terrain. Groundwater system in a top weathered regolith in a balastic terrain forms shallow aquifer is often classified into shallow water table category. In the present study an effort has been made to understand the suitable recharge zone with relation to rainfall and water level by using statistical analysis. Daily time series data of rainfall and borehole water level data are cross correlated to investigate variations in groundwater level response time during the months of monsoon. This measurement facilitate to demarcate favorable areas for Artificial Recharge. KEYWORDS

Ground water recharge and discharge in the central Everglades

USGS Publications Warehouse

Harvey, Judson W.; Krupa, Steven L.; Krest, James M.

2004-01-01

Rates of ground water recharge and discharge are not well known in the central Everglades. Here we report estimates of ground water recharge and discharge at 15 sites in the Everglades Nutrient Removal Project and in Water Conservation Area 2A (WCA-2A), along with measurements of hydraulic properties of peat at 11 sites. A simple hydrogeologic simulation was used to assess how specific factors have influenced recharge and discharge. Simulations and measurements agreed that the highest values of recharge and discharge occur within 600 m of levees, the result of ground water flow beneath levees. There was disagreement in the interior wetlands of WCA-2A (located > 1000 m from levees) where measurements of recharge and discharge were substantially higher than simulated fluxes. A five-year time series (1997 to 2002) of measured fluxes indicated that recharge and discharge underwent reversals in direction on weekly, monthly, and annual timescales at interior sites in WCA-2A. Ground water discharge tended to occur during average to moderately dry conditions when local surface water levels were decreasing. Recharge tended to occur during moderately wet periods or during very dry periods just as water levels began to increase following precipitation or in response to a pulse of surface water released from water-control structures by water managers. Discharge also tended to occur at sites in the wetland interior for ∼1 week preceding the arrival of the surface water pulse. We conclude that ground water recharge and discharge vary cyclically in the interior wetlands of the central Everglades, driven by the differential responses of surface water and ground water to annual, seasonal, and weekly trends in precipitation and operation of water-control structures.

Groundwater Modelling For Recharge Estimation Using Satellite Based Evapotranspiration

NASA Astrophysics Data System (ADS)

Soheili, Mahmoud; (Tom) Rientjes, T. H. M.; (Christiaan) van der Tol, C.

2017-04-01

Groundwater movement is influenced by several factors and processes in the hydrological cycle, from which, recharge is of high relevance. Since the amount of aquifer extractable water directly relates to the recharge amount, estimation of recharge is a perquisite of groundwater resources management. Recharge is highly affected by water loss mechanisms the major of which is actual evapotranspiration (ETa). It is, therefore, essential to have detailed assessment of ETa impact on groundwater recharge. The objective of this study was to evaluate how recharge was affected when satellite-based evapotranspiration was used instead of in-situ based ETa in the Salland area, the Netherlands. The Methodology for Interactive Planning for Water Management (MIPWA) model setup which includes a groundwater model for the northern part of the Netherlands was used for recharge estimation. The Surface Energy Balance Algorithm for Land (SEBAL) based actual evapotranspiration maps from Waterschap Groot Salland were also used. Comparison of SEBAL based ETa estimates with in-situ abased estimates in the Netherlands showed that these SEBAL estimates were not reliable. As such results could not serve for calibrating root zone parameters in the CAPSIM model. The annual cumulative ETa map produced by the model showed that the maximum amount of evapotranspiration occurs in mixed forest areas in the northeast and a portion of central parts. Estimates ranged from 579 mm to a minimum of 0 mm in the highest elevated areas with woody vegetation in the southeast of the region. Variations in mean seasonal hydraulic head and groundwater level for each layer showed that the hydraulic gradient follows elevation in the Salland area from southeast (maximum) to northwest (minimum) of the region which depicts the groundwater flow direction. The mean seasonal water balance in CAPSIM part was evaluated to represent recharge estimation in the first layer. The highest recharge estimated flux was for autumn

Soil moisture data as a constraint for groundwater recharge estimation

NASA Astrophysics Data System (ADS)

Mathias, Simon A.; Sorensen, James P. R.; Butler, Adrian P.

2017-09-01

Estimating groundwater recharge rates is important for water resource management studies. Modeling approaches to forecast groundwater recharge typically require observed historic data to assist calibration. It is generally not possible to observe groundwater recharge rates directly. Therefore, in the past, much effort has been invested to record soil moisture content (SMC) data, which can be used in a water balance calculation to estimate groundwater recharge. In this context, SMC data is measured at different depths and then typically integrated with respect to depth to obtain a single set of aggregated SMC values, which are used as an estimate of the total water stored within a given soil profile. This article seeks to investigate the value of such aggregated SMC data for conditioning groundwater recharge models in this respect. A simple modeling approach is adopted, which utilizes an emulation of Richards' equation in conjunction with a soil texture pedotransfer function. The only unknown parameters are soil texture. Monte Carlo simulation is performed for four different SMC monitoring sites. The model is used to estimate both aggregated SMC and groundwater recharge. The impact of conditioning the model to the aggregated SMC data is then explored in terms of its ability to reduce the uncertainty associated with recharge estimation. Whilst uncertainty in soil texture can lead to significant uncertainty in groundwater recharge estimation, it is found that aggregated SMC is virtually insensitive to soil texture.

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

USGS Publications Warehouse

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; Flint, Alan L.; Neff, Kirstin L.; Niraula, Rewati; Rodell, Matthew; Scanlon, Bridget R.; Singha, Kamini; Walvoord, Michelle Ann

2016-01-01

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

Implications of Projected Climate Change for Groundwater Recharge in the Western United States

NASA Technical Reports Server (NTRS)

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.;

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

Modeling Integrated Cave Drip Recharge Data using DReAM (Daily Recharge Assessment Model) in a Dry Eastern Mediterranean Area, Sif Cave - Israel

NASA Astrophysics Data System (ADS)

Anker, Y.; Sheffer, N. A.; Scanlon, B. R.; Gimburg, A.; Morin, E.

2010-12-01

Understanding recharge mechanisms and controls in karst regions is extremely important for managing water resources because of the dynamic nature of the system. To better understand this mechanism, a cave in the recharge area of the karstic Western Mountain Aquifer (WMA) of Israel was equipped to measure precipitation infiltration (2006-2008) by collecting integrated water drips from three areas in the cave (14, 46, and 52 m2 areas). Barrels equipped with pressure transducers record drip rate and volume for each of the three areas and enable estimation of recharge. A water budget model - DReAM (Daily Recharge Assessment Model) was used to quantify and predict infiltration behavior at the cave. DReAM includes calculations of all water cycle components - precipitation, evapotranspiration, runoff and recharge. The model was calibrated and validated using two independent sets of values, providing good agreement between calculated and observed data. Modeling results agree with previous studies that show: 1) three distinct flow paths (slow, intermediate, and fast flows) of water infiltrating at the cave; 2) a threshold of ~100 mm rain at the beginning of the rainy season for infiltration to begin; and 3) a decrease in lag time between rain events and infiltration response throughout the rainy season. This modeling tool and analysis approach can translate precipitation to groundwater recharge which will be very important for projecting future water resources in response to climate variability.

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.

Data-Conditioned Distributions of Groundwater Recharge Under Climate Change Scenarios

NASA Astrophysics Data System (ADS)

McLaughlin, D.; Ng, G. C.; Entekhabi, D.; Scanlon, B.

2008-12-01

Groundwater recharge is likely to be impacted by climate change, with changes in precipitation amounts altering moisture availability and changes in temperature affecting evaporative demand. This could have major implications for sustainable aquifer pumping rates and contaminant transport into groundwater reservoirs in the future, thus making predictions of recharge under climate change very important. Unfortunately, in dry environments where groundwater resources are often most critical, low recharge rates are difficult to resolve due to high sensitivity to modeling and input errors. Some recent studies on climate change and groundwater have considered recharge using a suite of general circulation model (GCM) weather predictions, an obvious and key source of uncertainty. This work extends beyond those efforts by also accounting for uncertainty in other land-surface model inputs in a probabilistic manner. Recharge predictions are made using a range of GCM projections for a rain-fed cotton site in the semi-arid Southern High Plains region of Texas. Results showed that model simulations using a range of unconstrained literature-based parameter values produce highly uncertain and often misleading recharge rates. Thus, distributional recharge predictions are found using soil and vegetation parameters conditioned on current unsaturated zone soil moisture and chloride concentration observations; assimilation of observations is carried out with an ensemble importance sampling method. Our findings show that the predicted distribution shapes can differ for the various GCM conditions considered, underscoring the importance of probabilistic analysis over deterministic simulations. The recharge predictions indicate that the temporal distribution (over seasons and rain events) of climate change will be particularly critical for groundwater impacts. Overall, changes in recharge amounts and intensity were often more pronounced than changes in annual precipitation and temperature

Estimates of ground-water recharge based on streamflow-hydrograph methods: Pennsylvania

USGS Publications Warehouse

Risser, Dennis W.; Conger, Randall W.; Ulrich, James E.; Asmussen, Michael P.

2005-01-01

This study, completed by the U.S. Geological Survey (USGS) in cooperation with the Pennsylvania Department of Conservation and Natural Resources, Bureau of Topographic and Geologic Survey (T&GS), provides estimates of ground-water recharge for watersheds throughout Pennsylvania computed by use of two automated streamflow-hydrograph-analysis methods--PART and RORA. The PART computer program uses a hydrograph-separation technique to divide the streamflow hydrograph into components of direct runoff and base flow. Base flow can be a useful approximation of recharge if losses and interbasin transfers of ground water are minimal. The RORA computer program uses a recession-curve displacement technique to estimate ground-water recharge from each storm period indicated on the streamflow hydrograph. Recharge estimates were made using streamflow records collected during 1885-2001 from 197 active and inactive streamflow-gaging stations in Pennsylvania where streamflow is relatively unaffected by regulation. Estimates of mean-annual recharge in Pennsylvania computed by the use of PART ranged from 5.8 to 26.6 inches; estimates from RORA ranged from 7.7 to 29.3 inches. Estimates from the RORA program were about 2 inches greater than those derived from the PART program. Mean-monthly recharge was computed from the RORA program and was reported as a percentage of mean-annual recharge. On the basis of this analysis, the major ground-water recharge period in Pennsylvania typically is November through May; the greatest monthly recharge typically occurs in March.

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.

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

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.

Quantifying depression-focused recharge in a seasonally frozen, semi-arid landscape

NASA Astrophysics Data System (ADS)

Cey, Edwin; Noorduijn, Saskia; Mohammed, Aaron; Pavlovskii, Igor; Bentley, Laurence; Hayashi, Masaki

2016-04-01

Groundwater recharge in the northern prairie region is influenced by seasonal accumulation of snowmelt runoff in numerous closed topographic depressions (tens to 100's of meters in size) that dot the landscape. Estimating recharge is difficult due to the number and complexity of processes at play, including snow redistribution, runoff, infiltration, evapotranspiration, lateral water redistribution, and recharge, which take place on clay-rich, macroporous sediments that are seasonally frozen. A multi-faceted study, referred to as the Groundwater Recharge in the Prairies (GRIP) project, was undertaken on the Canadian prairies in order to better understand the key hydrologic processes and to generate reliable basin-scale estimates of groundwater recharge that are necessary for sustainable groundwater management. Detailed monitoring of hydrological fluxes across individual depression-midslope-upland complexes was undertaken at three field sites located in different ecoregions, yielding valuable insights into the hydrologic processes and feedbacks within these individual micro-catchments. This process understanding was incorporated into a relatively simple one-dimensional (1D) water budget model, to which a new upscaling scheme was applied to estimate recharge over a watershed or multiple watersheds. The 1D model links upland and depression processes for an individual micro-catchment, and then upscales to a larger model grid cell based on a categorization of depressions based on their surface area and density within the grid cell. This approach enables explicit incorporation of relevant recharge processes, thus producing realistic recharge estimates, while limiting computational demand. The model has been calibrated and tested against a long-term data set from one of the field sites. Results demonstrate complex relationships between upland-depression water transfers and catchment geometry, resulting in maximal groundwater recharge in catchments with intermediate ratios

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 1974, water from Ship Creek was diverted at an average rate of approximately 6 cubic feet per second to an 11-acre recharge basin. Maximum sustained unit recharge for the basin was approximately 1.4 feet per day. Dur-ing 1975 a second basin of 8 acres was also used for recharge, and the total diversion rate was increased to as much as 30 cubic feet per second. The second basin was never completely filled, but the unit recharge rate was estimated to be 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.It was originally believed that because of the location of the recharge ponds within the natural recharge zone of the area's confined aquifer system, the source of the major portion of Anchorage's public water supply, most of the artificially recharged water would enter that system. However, water-level data and changes in saturation conditions interpreted from borehole geophysical logs indicate that most of the recharged water remained in the unconfined aquifer. In addition, 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 of water availability in Anchorage, unless diversion to the basins could be continued until January or February.

Recharge estimation in semi-arid karst catchments: Central West Bank, Palestine

NASA Astrophysics Data System (ADS)

Jebreen, Hassan; Wohnlich, Stefan; Wisotzky, Frank; Banning, Andre; Niedermayr, Andrea; Ghanem, Marwan

2018-03-01

Knowledge of groundwater recharge constitutes a valuable tool for sustainable management in karst systems. In this respect, a quantitative evaluation of groundwater recharge can be considered a pre-requisite for the optimal operation of groundwater resources systems, particular for semi-arid areas. This paper demonstrates the processes affecting recharge in Palestine aquifers. The Central Western Catchment is one of the main water supply sources in the West Bank. Quantification of potential recharge rates are estimated using chloride mass balance (CMB) and empirical recharge equations over the catchment. The results showing the spatialized recharge rate, which ranges from 111-216 mm/year, representing 19-37% of the long-term mean annual rainfall. Using Water Balance models and climatological data (e. g. solar radiation, monthly temperature, average monthly relative humidity and precipitation), actual evapotranspiration (AET) is estimated. The mean annual actual evapotranspiration was about 66-70% of precipitation.

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 M.; 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.

Experimental study on the artificial recharge of semiconfined aquifers involved in deep excavation engineering

NASA Astrophysics Data System (ADS)

Zheng, G.; Cao, J. R.; Cheng, X. S.; Ha, D.; Wang, F. J.

2018-02-01

Artificial recharge measures have been adopted to control the drawdown of confined aquifers and the ground subsidence caused by dewatering during deep excavation in Tianjin, Shanghai and other regions in China. However, research on recharge theory is still limited. Additionally, confined aquifers consisting of silt and silty sand in Tianjin have lower hydraulic conductivities than those consisting of sand or gravel, and the feasibility and effectiveness of recharge methods in these semiconfined aquifers urgently require investigation. A series of single-well and multiwell pumping and recharge tests was conducted at a metro station excavation site in Tianjin. The test results showed that it was feasible to recharge silt and silty sand semiconfined aquifers, and, to a certain extent, the hydrogeological parameters obtained from the pumping tests could be used to predict the water level rise during single-well recharge. However, the predicted results underestimated the water level rise near the recharge well (within 7 m) by approximately 10-25%, likely because the permeability coefficient around the well was reduced during the recharge process. Pressured recharge significantly improved the efficiency of the recharge process. Maintaining the recharge and pumping rates at a nearly equal level effectively controlled the surrounding surface and building settlement. However, the surrounding surface subsidence tended to rapidly develop when recharge stopped. Therefore, the recharge process should continue and gradually stop after the pumping stops. The twin-well combined recharge technique can be used to control the head loss of an aquifer when one of the recharge wells requires pumping to solve the associated clogging problems.

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

The nappes of the Lepontine dome: the influence of tectonic inheritance on their deformation style

NASA Astrophysics Data System (ADS)

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

2017-04-01

The Lepontine dome exposes the tectonostratigraphy of the Central Alps, from bottom-to-top, the subpenninic gneissic nappes of the Leventina, Simano, Adula/Cima-Lunga and Maggia. These units were part of a post-Variscan gneissic crust, which was intensely intruded by several generations of granitoids forming laccoliths and dikes of different shapes and sizes within paragneisses, augengneisses and amphibolites. During the Alpine orogenic cycle this initial and complex geological architecture was reshaped into a fold and thrust belt. We present the effect of these initial rheological anomalies along the Leventina, Simano and Adula/Cima-Lunga units through the geological map of the Osogna sheet (Swiss National Map no. 1293,1:25'000) together with structural and metamorphic data. The geological map shows that the Simano and Adula/Cima-Lunga units have an internal and lateral lithological variation at different scales as illustrated by the geological cross-sections. All lithologies present a penetrative amphibolite-facies foliation, which can vary in intensity among the rock-types. On the foliation plane a mineral and stretching lineation is visible dipping NW or SE, depending on the plane dip direction. The kinematic analysis indicates a top-to-the NW shearing. Despite this consistent structural data showing a regional dominant fabric, the folds (generally with a fold-axis parallel to the lineation) show different styles, depending on the thickness and the rock-type of the folded horizon and matrix, do not form laterally continuous structures and often are not cylindrical. As a consequence, such structures are interpreted as local perturbation rather than structures of regional importance. Furthermore, the Leventina and the Simano boundary is locally incongruent with the tectonic contact of the published maps. The amphibolite and paragneisses, used in the past as nappe divider, result to be deformed magmatic xenoliths. Therefore we present evidence (i) of a bottom

Ground-water recharge from streamflow data, NW Florida

USGS Publications Warehouse

Vecchioli, John; Bridges, W.C.; Rumenik, Roger P.; Grubbs, J.W.

1991-01-01

Annual base flows of streams draining Okaloosa County and adjacent areas in northwest Florida were determined through hydrograph separation and correlation techniques for purposes of evaluating variations in ground-water recharge rates. Base flows were least in the northern part of the county and greatest in the southern part. Topographic and soils data were then superimposed on the distribution of base flow by subbasin to produce a map showing distribution of ground-water recharge throughout the county. The highest recharge rate occurs in the southern part of the county where relatively flat upland areas underlain by excessively drained sandy soils result in minimal storm runoff and evapotranspiration.

Thermally-Rechargeable Electrochemical Cell

NASA Technical Reports Server (NTRS)

Richter, R.

1985-01-01

Proposed liquid-sodium/sulfur electrochemical cell recharged by heat, rather than electric generator. Concept suitable for energy storage for utilites, mobile electronic equipment, and solar thermoelectric power systems. Sodium ions driven across membrane with aid of temperature differential.

Fate of human viruses in groundwater recharge systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 ofmore » 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.« less

Ground-water pumpage and artificial recharge estimates for calendar year 2000 and average annual natural recharge and interbasin flow by hydrographic area, Nevada

USGS Publications Warehouse

Lopes, Thomas J.; Evetts, David M.

2004-01-01

Nevada's reliance on ground-water resources has increased because of increased development and surface-water resources being fully appropriated. The need to accurately quantify Nevada's water resources and water use is more critical than ever to meet future demands. Estimated ground-water pumpage, artificial and natural recharge, and interbasin flow can be used to help evaluate stresses on aquifer systems. In this report, estimates of ground-water pumpage and artificial recharge during calendar year 2000 were made using data from a variety of sources, such as reported estimates and estimates made using Landsat satellite imagery. Average annual natural recharge and interbasin flow were compiled from published reports. An estimated 1,427,100 acre-feet of ground water was pumped in Nevada during calendar year 2000. This total was calculated by summing six categories of ground-water pumpage, based on water use. Total artificial recharge during 2000 was about 145,970 acre-feet. At least one estimate of natural recharge was available for 209 of the 232 hydrographic areas (HAs). Natural recharge for the 209 HAs ranges from 1,793,420 to 2,583,150 acre-feet. Estimates of interbasin flow were available for 151 HAs. The categories and their percentage of the total ground-water pumpage are irrigation and stock watering (47 percent), mining (26 percent), water systems (14 percent), geothermal production (8 percent), self-supplied domestic (4 percent), and miscellaneous (less than 1 percent). Pumpage in the top 10 HAs accounted for about 49 percent of the total ground-water pumpage. The most ground-water pumpage in an HA was due to mining in Pumpernickel Valley (HA 65), Boulder Flat (HA 61), and Lower Reese River Valley (HA 59). Pumpage by water systems in Las Vegas Valley (HA 212) and Truckee Meadows (HA 87) were the fourth and fifth highest pumpage in 2000, respectively. Irrigation and stock watering pumpage accounted for most ground-water withdrawals in the HAs with the sixth

Ground-water recharge from small intermittent streams in the western Mojave Desert, California: Chapter G in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

USGS Publications Warehouse

Izbicki, John A.; Johnson, Russell U.; Kulongoski, Justin T.; Predmore, Steven; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

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

Determining Changes in Groundwater Quality during Managed Aquifer Recharge

NASA Astrophysics Data System (ADS)

Gambhir, T.; Houlihan, M.; Fakhreddine, S.; Dadakis, J.; Fendorf, S. E.

2016-12-01

Managed aquifer recharge (MAR) is becoming an increasingly prevalent technology for improving the sustainability of freshwater supply. However, recharge water can alter the geochemical conditions of the aquifer, mobilizing contaminants native to the aquifer sediments. Geochemical alterations on deep (>300 m) injection of highly treated recycled wastewater for MAR has received limited attention. We aim to determine how residual disinfectants used in water treatment processes, specifically the strong oxidants chloramine and hydrogen peroxide, affect metal mobilization within deep injection wells of the Orange County Water District. Furthermore, as the treated recharge water has very low ionic strength (44.6 mg L-1 total dissolved solids), we tested how differing concentrations of magnesium chloride and calcium chloride affected metal mobilization within deep aquifers. Continuous flow experiments were conducted on columns dry packed with sediments from a deep injection MAR site in Orange County, CA. The effluent was analyzed for shifts in water quality, including aqueous concentrations of arsenic, uranium, and chromium. Interaction between the sediment and oxic recharge solution causes naturally-occurring arsenopyrite to repartition onto iron oxides. The stability of arsenic on the newly precipitated iron oxides is dependent on pH changes during recharge.

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.

How to Recharge a Confined Alluvial Aquifer System

NASA Astrophysics Data System (ADS)

Maples, S.; Fogg, G. E.; Liu, Y.

2016-12-01

Greater water storage capacity is needed to offset future decreases in snowpack-water storage in California. Managed aquifer recharge (MAR) in California's Central Valley aquifer system is a promising alternative to new surface reservoir storage because it has the potential to both reduce overdraft conditions observed in many Central Valley groundwater basins and offset continued decreases in snowpack storage. MAR to the Central Valley's productive confined-aquifer system remains a challenge because, like most alluvial aquifer systems, it is composed mostly of silt and clay sediments that form nearly ubiquitous, multiple confining layers that inhibit direct recharge of the interconnected sand and gravel body networks. Several studies have mapped surficial soil types in the Central Valley that are conducive to MAR, but few studies have evaluated how subsurface geologic heterogeneity controls recharge to the confined aquifer system. Here, we use a transition probability Markov-chain geostatistical model conditioned with 1200 well logs to create a physically-realistic representation of the subsurface geologic heterogeneity in the American and Cosumnes River watersheds on the east side of the Sacramento Valley, CA, where studies have shown the presence of massive, interconnected, highly-permeable gravel deposits that are potentially conducive to considerably higher rates of regional recharge than would be possible over the rest of the landscape. Such localized stratigraphic features to support accelerated recharge occur throughout the Central Valley, but are mostly still undiscovered. A variably-saturated, fully-integrated, groundwater/surface-water code, ParFlow, was used to simulate MAR dynamics in this system. Results show the potential for (1) accelerated, high-volume recharge through interconnected gravels where they outcrop at land surface, and (2) regional repressurization of the deeper confined aquifer system. These findings provide insight into the critical

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.

Ground-water recharge in the arid and semiarid southwestern United States

USGS Publications Warehouse

Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

2007-01-01

Ground-water recharge in the arid and semiarid southwestern United States results from the complex interplay of climate, geology, and vegetation across widely ranging spatial and temporal scales. Present-day recharge tends to be narrowly focused in time and space. Widespread water-table declines accompanied agricultural development during the twentieth century, demonstrating that sustainable ground-water supplies are not guaranteed when part of the extracted resource represents paleorecharge. Climatic controls on ground-water recharge range from seasonal cycles of summer monsoonal and winter frontal storms to multimillennial cycles of glacial and interglacial periods. Precipitation patterns reflect global-scale interactions among the oceans, atmosphere, and continents. Large-scale climatic influences associated with El Niño and Pacific Decadal Oscillations strongly, but irregularly, control weather in the study area, so that year-to-year variations in precipitation and ground-water recharge are large and difficult to predict. Proxy data indicate geologically recent periods of naturally occurring multidecadal droughts unlike any in the modern instrumental record. Any anthropogenically induced climate change will likely reduce ground-water recharge through diminished snowpack at higher elevations. Future changes in El Niño and monsoonal patterns, both crucial to precipitation in the study area, are highly uncertain in current models. Current land-use modifications influence ground-water recharge through vegetation, irrigation, and impermeable area. High mountain ranges bounding the study area—the San Bernadino Mountains and Sierra Nevada to the west, and the Wasatch and southern Colorado Rocky Mountains to the east—provide external geologic controls on ground-water recharge. Internal geologic controls stem from tectonic processes that led to numerous, variably connected alluvial-filled basins, exposure of extensive Paleozoic aquifers in mountainous recharge

Indirect and direct recharges in a tropical forested watershed: Mule Hole, India

NASA Astrophysics Data System (ADS)

Maréchal, Jean-Christophe; Varma, Murari R. R.; Riotte, Jean; Vouillamoz, Jean-Michel; Kumar, M. S. Mohan; Ruiz, Laurent; Sekhar, M.; Braun, Jean-Jacques

2009-01-01

SummaryIt is commonly accepted that forest plays role to modify the water cycle at the watershed scale. However, the impact of forest on aquifer recharge is still discussed: some studies indicate that infiltration is facilitated under forest while other studies suggest a decrease of recharge. This paper presents an estimate of recharge rates to groundwater in a humid forested watershed of India. Recharge estimates are based on the joint use of several methods: chloride mass balance, water table fluctuation, geophysics, groundwater chemistry and flow analysis. Two components of the recharge (direct and indirect) are estimated over 3 years of monitoring (2003-2006). The direct and localized recharges resulting from rainfall over the entire watershed surface area is estimated to 45 mm/yr while the indirect recharge occurring from the stream during flood events is estimated to 30 mm/yr for a 2 km-long stream. Calculated recharge rates, rainfall and runoff measurements are then combined in a water budget to estimate yearly evapotranspiration which ranges from 80% to 90% of the rainfall, i.e. 1050 mm/y as an average. This unexpected high value for a deciduous forest is nevertheless in agreement with the forest worldwide relationship between rainfall and evapotranspiration. The large evapotranspiration from the forest cover contributes to decrease the recharge rate which leads to a lowering of the water table. This is the reason why the stream is highly ephemeral.

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.

Tectono-thermal evolution in a region with thin-skinned tectonics: the western nappes in the Cantabrian Zone (Variscan belt of NW Spain)

NASA Astrophysics Data System (ADS)

Bastida, F.; Brime, C.; García-López, S.; Sarmiento, G. N.

The palaeotemperature distribution in the transition from diagenesis to metamorphism in the western nappes of the Cantabrian Zone (Somiedo, La Sobia and Aramo Units) are analysed by conodont colour alteration index (CAI) and illite crystallinity (IC). Structural and stratigraphic control in distribution of CAI and IC values is observed. Both CAI and IC value distributions show that anchizonal conditions are reached in the lower part of the Somiedo Unit. A disruption of the thermal trend by basal thrusts is evidenced by CAI and IC values. There is an apparent discrepancy between the IC and CAI values in Carboniferous rocks of the Aramo Unit; the IC has mainly anchizonal values, whereas the CAI has diagenetic values. Discrepant IC values are explained as a feature inherited from the source area. In the Carboniferous rocks of the La Sobia Unit, both IC and CAI indicate diagenetic conditions. The anchimetamorphism predated completion of emplacement of the major nappes; it probably developed previously and/or during the early stages of motion of the units. Temperature probably decreased when the metamorphosed zones of the sheets rose along ramps and were intensely eroded. In the context of the Iberian Variscan belt, influence of tectonic factors on the metamorphism is greater in the internal parts, where the strain and cleavage are always present, than in the external parts (Cantabrian Zone), where brittle deformation and rock translation are dominant, with an increasing role of the burial on the metamorphism.

Novel rechargeable calcium phosphate nanocomposite with antibacterial activity to suppress biofilm acids and dental caries.

PubMed

Al-Dulaijan, Yousif A; Cheng, Lei; Weir, Michael D; Melo, Mary Anne S; Liu, Huaibing; Oates, Thomas W; Wang, Lin; Xu, Hockin H K

2018-05-01

Rechargeable calcium phosphate (CaP) composites were developed recently. However, none of the rechargeable CaP composites was antibacterial. The objectives of this study were to develop the first rechargeable CaP composite that was antibacterial, and to investigate the effects of adding dimethylaminohexadecyl methacrylate (DMAHDM) into rechargeable CaP composite on ion rechargeability and re-release as well as biofilm properties. DMAHDM was synthesized via a Menschutkin reaction. Nanoparticles of amorphous calcium phosphate (NACP) were synthesized using a spray-drying technique. The resin contained ethoxylated bisphenol A dimethacrylate (EBPADMA) and pyromellitic glycerol dimethacrylate (PMGDM). Two composites were fabricated: rechargeable NACP composite, and rechargeable NACP-DMAHDM composite. Mechanical properties and ion release and recharge were measured. A dental plaque microcosm biofilm model using saliva was tested. Flexural strength and elastic modulus of rechargeable NACP and NACP-DMAHDM composites matched commercial control composite (p > 0.1). NACP-DMAHDM inhibited biofilm metabolic activity and lactic acid, and reduced biofilm colony-forming units (CFU) by 3-4 log. NACP and NACP-DMAHDM showed similar Ca and P ion recharge and re-release (p > 0.1). Therefore, adding DMAHDM did not compromise the ion rechargeability. One recharge yielded continuous release for 42 d. The release was maintained at the same level with increasing number of recharge cycles, indicating long-term ion release and remineralization capability. The first CaP rechargeable and antibacterial composite was developed. Adding DMAHDM into the rechargeable NACP composite did not adversely affect the Ca and P ion release and recharge, and the composite had much less biofilm growth and lactic acid production, with CFU reduction by 3-4 log. This novel CaP rechargeable composite with long-term remineralization and antibacterial properties is promising for tooth restorations to inhibit

A computer program for predicting recharge with a master recession curve

USGS Publications Warehouse

Heppner, Christopher S.; Nimmo, John R.

2005-01-01

Water-table fluctuations occur in unconfined aquifers owing to ground-water recharge following precipitation and infiltration, and ground-water discharge to streams between storm events. Ground-water recharge can be estimated from well hydrograph data using the water-table fluctuation (WTF) principle, which states that recharge is equal to the product of the water-table rise and the specific yield of the subsurface porous medium. The water-table rise, however, must be expressed relative to the water level that would have occurred in the absence of recharge. This requires a means for estimating the recession pattern of the water-table at the site. For a given site there is often a characteristic relation between the water-table elevation and the water-table decline rate following a recharge event. A computer program was written which extracts the relation between decline rate and water-table elevation from well hydrograph data and uses it to construct a master recession curve (MRC). The MRC is a characteristic water-table recession hydrograph, representing the average behavior for a declining water-table at that site. The program then calculates recharge using the WTF method by comparing the measured well hydrograph with the hydrograph predicted by the MRC and multiplying the difference at each time step by the specific yield. This approach can be used to estimate recharge in a continuous fashion from long-term well records. Presented here is a description of the code including the WTF theory and instructions for running it to estimate recharge with continuous well hydrograph data.

Infiltration in layered loessial deposits: Revised numerical simulations and recharge assessment

NASA Astrophysics Data System (ADS)

Dafny, Elad; Šimůnek, Jirka

2016-07-01

The objective of this study is to assess recharge rates and their timing under layered loessial deposits at the edge of arid zones. Particularly, this study is focused on the case of the coastal plain of Israel and Gaza. First, results of a large-scale field infiltration test were used to calibrate the van Genuchten parameters of hydraulic properties of the loessial sediments using HYDRUS (2D/3D). Second, optimized soil hydraulic parameters were used by HYDRUS-1D to simulate the water balance of the sandy-loess sediments during a 25-year period (1990-2015) for three environmental conditions: bare soil, and soil with both sparse and dense natural vegetation. The best inverse parameter optimization run fitted the infiltration test data with the RMSE of 0.27 d (with respect to a moisture front arrival) and R2 of 96%. The calibrated model indicates that hydraulic conductivities of the two soil horizons, namely sandy loam and sandy clay loam, are 81 cm/d and 17.5 cm/d, respectively. These values are significantly lower than those previously reported, based on numerical simulations, for the same site. HYDRUS-1D simulation of natural recharge under bare soil resulted in recharge estimates (to the aquifer) in the range of 21-93 mm/yr, with an average recharge of 63 mm/yr. Annual precipitation in the same period varied between 100 and 300 mm/yr, with an average of 185 mm/yr. For semi-stabilized dunes, with 26% of the soil surface covered by local shrub (Artemisia monosperma), the mean annual recharge was 28 mm. For the stabilized landscape, with as much as 50% vegetation coverage, it was only 2-3 mm/yr. In other words, loessial sediments can either be a source of significant recharge, or of no recharge at all, depending on the degree of vegetative cover. Additionally, the time lag between specific rainy seasons and corresponding recharge events at a depth of 22 m, increased from 2.5 to 5 years, and to about 20 years, respectively, with an increasing vegetative cover. For

Rechargeable dental adhesive with calcium phosphate nanoparticles for long-term ion release

PubMed Central

Zhang, Ling; Weir, Michael D.; Hack, Gary; Fouad, Ashraf F.; Xu, Hockin H. K.

2015-01-01

Objectives The tooth-resin bond is the weak link of restoration, with secondary caries as a main reason for failure. Calcium phosphate-containing resins are promising for remineralization; however, calcium (Ca) and phosphate (P) ion releases last only a couple of months. The objectives of this study were to develop the first rechargeable CaP bonding agent and investigate the key factors that determine CaP ion recharge and re-release. Methods Nanoparticles of amorphous calcium phosphate (NACP) were synthesized. Pyromellitic glycerol dimethacrylate (PMGDM), ethoxylated bisphenol-A dimethacrylate (EBPADMA), 2-hydroxyethyl methacrylate (HEMA), and bisphenol-A glycidyl dimethacrylate (BisGMA) were used to synthesize three adhesives (denoted PE, PEH and PEHB). NACP were mixed into adhesive at 0–30% by mass. Dentin shear bond strengths were measured. Adhesive specimens were tested for Ca and P initial ion release. Then the ion-exhausted specimens were immersed in Ca and P solution to recharge the specimens, and the recharged specimens were then used to measure ion re-release for 7 days as one cycle. Then these specimens were again recharged and the re-release was measured for 7 days as the second cycle. Three recharge/re-release cycles were tested. Results PEHB had the highest dentin bond strength (p<0.05). Increasing NACP content from 0 to 30% did not affect dentin bond strength (p>0.1), but increased CaP release and re-release (p<0.05). PEHB-NACP had the greatest recharge/re-release, and PE-NACP had the least (p<0.05). Ion release remained high and did not decrease with increasing the number of recharge/re-release cycles (p>0.1). After the third cycle, specimens without further recharge had continuous CaP ion release for 2–3 weeks. Significance Rechargeable CaP bonding agents were developed for the first time to provide long-term Ca and P ions to promote remineralization and reduce caries. Incorporation of NACP into adhesive had no negative effect on dentin bond

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.

How to Recharge a Confined Aquifer: An Exploration of Geologic Controls on Groundwater Storage.

NASA Astrophysics Data System (ADS)

Maples, S.; Fogg, G. E.; Maxwell, R. M.; Liu, Y.

2017-12-01

Decreased snowpack storage and groundwater overdraft in California has increased interest in managed aquifer recharge (MAR) of excess winter runoff to the Central Valley aquifer system, which has unused storage capacity that far exceeds the state's surface reservoirs. Recharge to the productive, confined aquifer system remains a challenge due to the presence of nearly-ubiquitous, multiple silt and clay confining units that limit recharge pathways. However, previous studies have identified interconnected networks of sand and gravel deposits that bypass the confining units and accommodate rapid, high-volume recharge to the confined aquifer system in select locations. We use the variably-saturated, fully-integrated groundwater/surface-water flow code, ParFlow, in combination with a high-resolution, transition probability Markov-chain geostatistical model of the subsurface geologic heterogeneity of the east side of the Sacramento Valley, CA, to characterize recharge potential across a landscape that includes these geologic features. Multiple 180-day MAR simulations show that recharge potential is highly dependent on subsurface geologic structure, with a several order-of-magnitude range of recharge rates and volumes across the landscape. Where there are recharge pathways to the productive confined-aquifer system, pressure propagation in the confined system is widespread and rapid, with multi-kilometer lateral pressure propagation. Although widespread pressure propagation occurs in the confined system, only a small fraction of recharge volume is accommodated there. Instead, the majority of recharge occurs by filling unsaturated pore spaces. Where they outcrop at land surface, high-K recharge pathways fill rapidly, accommodating the majority of recharge during early time. However, these features become saturated quickly, and somewhat counterintuitively, the low-K silt and clay facies accommodate the majority of recharge volume during most of the simulation. These findings

Predicting groundwater recharge for varying land cover and climate conditions - a global meta-study

NASA Astrophysics Data System (ADS)

Mohan, Chinchu; Western, Andrew W.; Wei, Yongping; Saft, Margarita

2018-05-01

Groundwater recharge is one of the important factors determining the groundwater development potential of an area. Even though recharge plays a key role in controlling groundwater system dynamics, much uncertainty remains regarding the relationships between groundwater recharge and its governing factors at a large scale. Therefore, this study aims to identify the most influential factors of groundwater recharge, and to develop an empirical model to estimate diffuse rainfall recharge at a global scale. Recharge estimates reported in the literature from various parts of the world (715 sites) were compiled and used in model building and testing exercises. Unlike conventional recharge estimates from water balance, this study used a multimodel inference approach and information theory to explain the relationship between groundwater recharge and influential factors, and to predict groundwater recharge at 0.5° resolution. The results show that meteorological factors (precipitation and potential evapotranspiration) and vegetation factors (land use and land cover) had the most predictive power for recharge. According to the model, long-term global average annual recharge (1981-2014) was 134 mm yr-1 with a prediction error ranging from -8 to 10 mm yr-1 for 97.2 % of cases. The recharge estimates presented in this study are unique and more reliable than the existing global groundwater recharge estimates because of the extensive validation carried out using both independent local estimates collated from the literature and national statistics from the Food and Agriculture Organization (FAO). In a water-scarce future driven by increased anthropogenic development, the results from this study will aid in making informed decisions about groundwater potential at a large scale.

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.

Glacierized headwater streams as aquifer recharge corridors, subarctic Alaska

USGS Publications Warehouse

Lilledahl, Anna K.; Gadeke, Anne; O'Neel, Shad; Gatesman, T. A.; Douglas, T. A.

2017-01-01

Arctic river discharge has increased in recent decades although sources and mechanisms remain debated. Abundant literature documents permafrost thaw and mountain glacier shrinkage over the past decades. Here we link glacier runoff to aquifer recharge via a losing headwater stream in subarctic Interior Alaska. Field measurements in Jarvis Creek (634 km2), a subbasin of the Tanana and Yukon Rivers, show glacier meltwater runoff as a large component (15–28%) of total annual streamflow despite low glacier cover (3%). About half of annual headwater streamflow is lost to the aquifer (38 to 56%). The estimated long-term change in glacier-derived aquifer recharge exceeds the observed increase in Tanana River base flow. Our findings suggest a linkage between glacier wastage, aquifer recharge along the headwater stream corridor, and lowland winter discharge. Accordingly, glacierized headwater streambeds may serve as major aquifer recharge zones in semiarid climates and therefore contributing to year-round base flow of lowland rivers.

Recharge characteristics of an unconfined aquifer from the rainfall-water table relationship

NASA Astrophysics Data System (ADS)

Viswanathan, M. N.

1984-02-01

The determination of recharge levels of unconfined aquifers, recharged entirely by rainfall, is done by developing a model for the aquifer that estimates the water-table levels from the history of rainfall observations and past water-table levels. In the present analysis, the model parameters that influence the recharge were not only assumed to be time dependent but also to have varying dependence rates for various parameters. Such a model is solved by the use of a recursive least-squares method. The variable-rate parameter variation is incorporated using a random walk model. From the field tests conducted at Tomago Sandbeds, Newcastle, Australia, it was observed that the assumption of variable rates of time dependency of recharge parameters produced better estimates of water-table levels compared to that with constant-recharge parameters. It was observed that considerable recharge due to rainfall occurred on the very same day of rainfall. The increase in water-table level was insignificant for subsequent days of rainfall. The level of recharge very much depends upon the intensity and history of rainfall. Isolated rainfalls, even of the order of 25 mm day -1, had no significant effect on the water-table levels.

Estimating Monetized Benefits of Groundwater Recharge from Stormwater Retention Practices

EPA Pesticide Factsheets

The purpose of the study is to inform valuation of groundwater recharge from stormwater retention in areas projected for new development and redevelopment. This study examined a simplified methodology for estimating recharge volume.

Catchment-scale groundwater recharge and vegetation water use efficiency

NASA Astrophysics Data System (ADS)

Troch, P. A. A.; Dwivedi, R.; Liu, T.; Meira, A.; Roy, T.; Valdés-Pineda, R.; Durcik, M.; Arciniega, S.; Brena-Naranjo, J. A.

2017-12-01

Precipitation undergoes a two-step partitioning when it falls on the land surface. At the land surface and in the shallow subsurface, rainfall or snowmelt can either runoff as infiltration/saturation excess or quick subsurface flow. The rest will be stored temporarily in the root zone. From the root zone, water can leave the catchment as evapotranspiration or percolate further and recharge deep storage (e.g. fractured bedrock aquifer). Quantifying the average amount of water that recharges deep storage and sustains low flows is extremely challenging, as we lack reliable methods to quantify this flux at the catchment scale. It was recently shown, however, that for semi-arid catchments in Mexico, an index of vegetation water use efficiency, i.e. the Horton index (HI), could predict deep storage dynamics. Here we test this finding using 247 MOPEX catchments across the conterminous US, including energy-limited catchments. Our results show that the observed HI is indeed a reliable predictor of deep storage dynamics in space and time. We further investigate whether the HI can also predict average recharge rates across the conterminous US. We find that the HI can reliably predict the average recharge rate, estimated from the 50th percentile flow of the flow duration curve. Our results compare favorably with estimates of average recharge rates from the US Geological Survey. Previous research has shown that HI can be reliably estimated based on aridity index, mean slope and mean elevation of a catchment (Voepel et al., 2011). We recalibrated Voepel's model and used it to predict the HI for our 247 catchments. We then used these predicted values of the HI to estimate average recharge rates for our catchments, and compared them with those estimated from observed HI. We find that the accuracies of our predictions based on observed and predicted HI are similar. This provides an estimation method of catchment-scale average recharge rates based on easily derived catchment

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. Agricultural 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 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.

Recharge to the surficial aquifer system in Lee and Hendry counties, Florida

USGS Publications Warehouse

Krulikas, R.K.; Giese, G.L.

1995-01-01

Protection of ground-water recharge areas against contamination is of great interest in Florida, a State whose population depends heavily on ground water and that is experiencing rapid growth. The Florida Legislature is considering implementation of a tax incentive program to owners of high-rate recharge lands that remain undeveloped. High-rate recharge was arbitrarily set at 10 or more inches per year. The U.S. Geological Survey, in cooperation with the South Florida Water Management District, conducted a study to investigate the efficacy of several methods for estimating recharge to the surficial aquifer system in southwestern Florida and to map recharge at a scale of 1:100,000. Four maps were constructed at a scale of 1:100,000 for Lee and Hendry Counties, depicting the configuration of the water table of the surficial aquifer system, direction of ground-water flow, general soil characteristics, and recharge rates. Point recharge rates calculated for 25 sites in Lee County from comparisons of chloride concentrations in precipitation and in water from the surficial aquifer system ranged from 0.6 to 9.0 inches per year. Local recharge rates estimated by increases in flow along theoretical flow tubes in the surficial aquifer system were 8.0 inches per year in a part of Lee County and 8.2 inches per year in a part of Hendry County. Information on oxygen isotopes in precipitation and water from the surficial aquifer system was used to verify that the source of chlorides in the aquifer system was from precipitation rather than upward leakage of saline water. Soil maps and general topographic and hydrologic considerations were used with calculated point and local recharge rates to regionalize rates throughout Lee and Hendry Counties. The areas of greatest recharge were found in soils of flatwoods and sloughs, which were assigned estimated recharge rates of 0 to 10 inches per year. Soils of swamps and sloughs were assigned values of 0 to 3.0 inches per year; soils of

Sulfone-based electrolytes for aluminium rechargeable batteries.

PubMed

Nakayama, Yuri; Senda, Yui; Kawasaki, Hideki; Koshitani, Naoki; Hosoi, Shizuka; Kudo, Yoshihiro; Morioka, Hiroyuki; Nagamine, Masayuki

2015-02-28

Electrolyte is a key material for success in the research and development of next-generation rechargeable batteries. Aluminium rechargeable batteries that use aluminium (Al) metals as anode materials are attractive candidates for next-generation batteries, though they have not been developed yet due to the lack of practically useful electrolytes. Here we present, for the first time, non-corrosive reversible Al electrolytes working at room temperature. The electrolytes are composed of aluminium chlorides, dialkylsulfones, and dilutants, which are realized by the identification of electrochemically active Al species, the study of sulfone dependences, the effects of aluminium chloride concentrations, dilutions and their optimizations. The characteristic feature of these materials is the lower chloride concentrations in the solutions than those in the conventional Al electrolytes, which allows us to use the Al metal anodes without corrosions. We anticipate that the sulfone-based electrolytes will open the doors for the research and development of Al rechargeable batteries.

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.

Regional analysis of ground-water recharge: Chapter B in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

USGS Publications Warehouse

Flint, Lorraine E.; Flint, Alan L.; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

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

Déprescription des agonistes des récepteurs des benzodiazépines

PubMed Central

Pottie, Kevin; Thompson, Wade; Davies, Simon; Grenier, Jean; Sadowski, Cheryl A.; Welch, Vivian; Holbrook, Anne; Boyd, Cynthia; Swenson, Robert; Ma, Andy; Farrell, Barbara

2018-01-01

Résumé Objectif Formuler des lignes directrices fondées sur les données probantes visant à aider les cliniciens à décider du moment et de la façon sécuritaire de réduire la dose des agonistes des récepteurs des benzodiazépines (BZRA) pour mettre fin au traitement; se concentrer sur le niveau le plus élevé des données disponibles et obtenir les commentaires des professionnels de première ligne durant le processus de rédaction, de révision et d’adoption des lignes directrices. Méthodes L’équipe comptait 8 cliniciens (1 médecin de famille, 2 psychiatres, 1 psychologue clinique, 1 pharmacologue clinique, 2 pharmaciennes cliniques et 1 gériatre) et une spécialiste de la méthodologie; les membres ont divulgué tout conflit d’intérêts. Nous avons eu recours à un processus systématique, y compris l’approche GRADE (Grading of Recommendations Assessment, Development and Evaluation) pour formuler les lignes directrices. Les données ont été générées par une revue systématique d’études portant sur la déprescription des BZRA contre l’insomnie, de même que par une revue des revues sur les torts liés à la poursuite du traitement par BZRA et des synthèses narratives sur les préférences des patients et les répercussions sur les ressources. Ces données et le score GRADE de qualité des données ont servi à formuler les recommandations. L’équipe a peaufiné le texte sur le contenu et les recommandations des lignes directrices par consensus et a synthétisé les considérations cliniques afin de répondre aux questions des cliniciens de première ligne. Une version préliminaire des lignes directrices a été révisée par les cliniciens et les intervenants. Recommandations Nous recommandons d’offrir la déprescription (réduction lente de la dose) des BZRA à tous les patients âgés (≥ 65 ans) sous un BZRA, sans égard à la durée de l’usage, et suggérons d’offrir la déprescription (réduction lente de la dose) �

Role of vegetation in interplay of climate, soil and groundwater recharge in a global dataset

NASA Astrophysics Data System (ADS)

Kim, J. H.; Jackson, R. B.

2010-12-01

Groundwater is an essential resource for people and ecosystems worldwide. Our capacity to ameliorate predicted global water shortages and to maintain sustainable water supplies depend on a better understanding of the controls of recharge and how vegetation change may affect recharge mechanisms. The goals of this study are to quantify the importance of vegetation as a dominant control on recharge globally and to compare the importance of vegetation with other hydrologically important variables, including climate and soil. We based our global analysis on > 500 recharge estimates from the literature that contained information on vegetation, soil and climate or location. Plant functional types significantly affected groundwater recharge rates substantially. After climatic factors (water inputs, PET, and seasonality), vegetation types explained about 15% of the residuals in the dataset. Across all climatic factors, croplands had the highest recharge rates, followed by grasslands, scrublands and woodlands (average recharge: 75, 63, 30, 22 mm/yr respectively). Recharge under woodlands showed the most nonlinear response to water inputs. Differences in recharge between the vegetation types were more exaggerated at arid climates and in clay soils, indicating greater biological control on soil water fluxes in these conditions. Our results shows that vegetation greatly affects recharge rates globally and alters relationship between recharge and physical variables allowing us to better predict recharge rates globally.

Serpentinite slices within a tectonic zone at the base of the Juvavic nappe system in the Northern Calcareous Alps (Austria): characterization and origin

NASA Astrophysics Data System (ADS)

Boehm, Katharina; Schuster, Ralf; Wagreich, Michael; Koller, Friedrich; Wimmer-Frey, Ingeborg

2014-05-01

The investigated serpentinites are present in an ENE-WSW orientated tectonic zone at the base of Juvavic nappes (Northern Calcareous Alps), situated at the eastern margin of the Eastern Alps (Lower Austria). They form small tectonically squeezed slices, which are embedded in Permotriassic schists and Middle to Upper Triassic limestones. These serpentinites play an important, but not yet understood role in reconstructing Neotethys evolution, Alpine Orogeny and the correlation of Dinarides and Alps. The largest serpentinite body near to Unterhöflein is 400 to 100 meters in size and was investigated by mineralogical (XRD) and petrological/geochemical (XRF) methods. The primary mineral composition is olivine + orthopyroxene + clinopyroxene + chrome spinel. Pseudomorphs of pyroxenes are visible macroscopically, but almost all primary minerals are replaced by serpentine minerals. Former olivine is converted to chrysotile minerals, which show typical reticulate textures, orthopyroxene turned into lizardite pseudomorphs and chrome spinel is almost completely altered to magnetite. Major contents of chrysotile-α, chrysotile-γ and lizardite and minor antigorite, as well as secondary minerals like talc, chlorite and hydrogrossular were identified with XRD. Results from whole rock geochemistry indicate harzburgitic precursor rocks for the serpentinites. According to the low antigorite content, the rocks have only a weak metamorphic imprint and therefore an obduction rather than a subduction history is likely. This leads to the assumption that these serpentinites possibly originate from the Neotethys and not from the Penninic oceanic realm. Further, the tectonic position of the serpentinite slices is in close vicinity to sediments of the Meliata unit which also occur between Juvavic and underlying Tirolic nappe system (Mandl & Ondrejickova, 1993). Additionally, remnants from ophiolite nappes are found reworked into the surrounding Upper Cretaceous Gosau Group. In the latter

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.

Inferring time-varying recharge from inverse analysis of long-term water levels

NASA Astrophysics Data System (ADS)

Dickinson, Jesse E.; Hanson, R. T.; Ferré, T. P. A.; Leake, S. A.

2004-07-01

Water levels in aquifers typically vary in response to time-varying rates of recharge, suggesting the possibility of inferring time-varying recharge rates on the basis of long-term water level records. Presumably, in the southwestern United States (Arizona, Nevada, New Mexico, southern California, and southern Utah), rates of mountain front recharge to alluvial aquifers depend on variations in precipitation rates due to known climate cycles such as the El Niño-Southern Oscillation index and the Pacific Decadal Oscillation. This investigation examined the inverse application of a one-dimensional analytical model for periodic flow described by Lloyd R. Townley in 1995 to estimate periodic recharge variations on the basis of variations in long-term water level records using southwest aquifers as the case study. Time-varying water level records at various locations along the flow line were obtained by simulation of forward models of synthetic basins with applied sinusoidal recharge of either a single period or composite of multiple periods of length similar to known climate cycles. Periodic water level components, reconstructed using singular spectrum analysis (SSA), were used to calibrate the analytical model to estimate each recharge component. The results demonstrated that periodic recharge estimates were most accurate in basins with nearly uniform transmissivity and the accuracy of the recharge estimates depends on monitoring well location. A case study of the San Pedro Basin, Arizona, is presented as an example of calibrating the analytical model to real data.

Inferring time‐varying recharge from inverse analysis of long‐term water levels

USGS Publications Warehouse

Dickinson, Jesse; Hanson, R.T.; Ferré, T.P.A.; Leake, S.A.

2004-01-01

Water levels in aquifers typically vary in response to time‐varying rates of recharge, suggesting the possibility of inferring time‐varying recharge rates on the basis of long‐term water level records. Presumably, in the southwestern United States (Arizona, Nevada, New Mexico, southern California, and southern Utah), rates of mountain front recharge to alluvial aquifers depend on variations in precipitation rates due to known climate cycles such as the El Niño‐Southern Oscillation index and the Pacific Decadal Oscillation. This investigation examined the inverse application of a one‐dimensional analytical model for periodic flow described by Lloyd R. Townley in 1995 to estimate periodic recharge variations on the basis of variations in long‐term water level records using southwest aquifers as the case study. Time‐varying water level records at various locations along the flow line were obtained by simulation of forward models of synthetic basins with applied sinusoidal recharge of either a single period or composite of multiple periods of length similar to known climate cycles. Periodic water level components, reconstructed using singular spectrum analysis (SSA), were used to calibrate the analytical model to estimate each recharge component. The results demonstrated that periodic recharge estimates were most accurate in basins with nearly uniform transmissivity and the accuracy of the recharge estimates depends on monitoring well location. A case study of the San Pedro Basin, Arizona, is presented as an example of calibrating the analytical model to real data.

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

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.

Seismic Signals Recorded During Artificial and Natural Karst Recharge Events

NASA Astrophysics Data System (ADS)

Bilek, S. L.; Luhmann, A. J.; Diniakos, R. S.; Morton, E.; Rinehart, A. J.; Alexander, E. C., Jr.; Alexander, S. C.; Larsen, M.; Green, J. A.

2016-12-01

Seismology has recently been used to explore a variety of surficial processes, including tracking landslides, glaciers, and river flow. The seismic data collected can provide useful information about these flow processes, particularly in areas where other flow-related observations are difficult to make. Underground flow through karst aquifers is an area of significant interest, where most of the flow occurs through preferential flow conduits whose locations are largely unknown. We investigate seismic signals generated by both controlled and natural recharge into a karst aquifer system located near Bear Spring, near Eyota, MN, USA. The controlled recharge experiments involved injecting a pool full of water ( 13,000 L) into a dry overflow spring, which then flowed underground until it was discharged at Bear Spring. The natural recharge fortuitously involved a large rainstorm that supplied over 2 inches of rain in a few hour period, which caused the overflow spring to start flowing and total discharge to increase from a background of 100 L/s to 300 L/s. These events were recorded by 12 seismometers (11 short period and 1 broadband with 500 Hz sampling rate) all placed within the 4500 m2 area containing the dry overflow spring and predicted underground flow path. Spectrograms for the artificial and natural recharge events show significant seismic energy over a broad frequency range (few to nearly 220 Hz) during the periods of artificial recharge, largely contained during the period of water injection. Stations closest to Bear Spring see peak seismic energy in the 20-30 Hz range during these tests, likely related to changes in the underground water flow. During the natural recharge event, we find much longer duration of seismic energy over the broad frequency range. We compare these seismic results with discharge measurements conducted during all tests at Bear Spring, as well as with rainfall measurements recorded for the natural recharge event.

Rechargeable internal neural stimulators--is there a problem with efficacy?

PubMed

Harries, Anwen M; Major, Shannon; Sandhu, Mandeep; Honey, Christopher R

2012-01-01

With the advent of rechargeable internal neural stimulators (rINS) for deep brain stimulation, our aim was to survey patient satisfaction and clinical efficacy in an early cohort of patients receiving this new technology. This is an observational study on nine patients with rINS. All patients had initially received non-rechargeable INS with established efficacy of their deep brain stimulation system for either dystonia or pain. Patient satisfaction and efficacy with their rINS were established by completion of a questionnaire, a quality of life assessment (SF-36), and calculation of the total electrical energy delivered (TEED) by the rINS. A reduction in efficacy of their rINS was noticed in 22% of patients. In 78% of patients, there was a problem with recharging their rINS because of poor contact. Two patients (22%) felt that recharging the rINS interfered with their lives and it was a daily reminder that they had a deep brain stimulator system in situ. Eight out of nine patients (89%), however, would recommend to other patients to have an rINS. Most patients were happy with their rechargeable internal neural stimulator. A reduction in efficacy was noticed in 22% of patients, which is similar to the proportion of patients noticing a reduction in efficacy when replacing with a non-rechargeable system. Thus, all patients require close monitoring post-replacement of rINS, in case possible adjustment of parameters is required. © 2011 International Neuromodulation Society.

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

NASA Astrophysics Data System (ADS)

Tanco, Raúl; Kruse, Eduardo

2001-07-01

The fluctuation of the water table east of La Pampa province and northwest of Buenos Aires province, Argentina, influences agricultural production in the region because it is closely related to the alternation of dry and wet periods. Sea-surface temperature (SST) anomalies have been used as predictors to forecast atmospheric variables in different regions of the world. The objective of this work is to present a simple model to forecast seasonal rainfall using SST distribution in the Pacific Ocean as a predictor. Once the relationship between precipitation and water-table fluctuations was established, a methodology for the prediction of water-table fluctuations was developed. A good agreement between observed and predicted water-table fluctuations was found when estimating water-table fluctuations in the summer and autumn seasons. Résumé. Les fluctuations de la nappe à l'est de la province de La Pampa et au nord-ouest de la province de Buenos Aires (Argentine) influence la production agricole de la région parce qu'elle est étroitement liée à l'alternance de saisons sèches et humides. Les anomalies de la température de surface de l'océan (SST) ont été utilisées comme prédicteurs pour prévoir les variables atmosphériques dans différentes régions du monde. L'objectif de ce travail est de présenter un modèle simple de prévision des précipitations saisonnières en utilisant comme prédicteur la distribution des SST dans l'Océan Pacifique. Une fois que la relation entre les fluctuations des précipitations et celles de la nappe a été établie, une méthodologie de prédiction des variations de la nappe a été mise au point. Un bon accord entre les variations de la nappe observées et celles prédites a été trouvé pour les estimations des variations de nappe en été et en automne. Resumen. La fluctuación del nivel freático al este de la provincia de La Pampa y al nordeste de la de Buenos Aires (Argentina) repercute en la producción agr

How Might Recharge Change Under Projected Climate Change in the Western U.S.?

NASA Astrophysics Data System (ADS)

Niraula, R.; Meixner, T.; Dominguez, F.; Bhattarai, N.; Rodell, M.; Ajami, H.; Gochis, D.; Castro, C.

2017-10-01

Although groundwater is a major water resource in the western U.S., little research has been done on the impacts of climate change on groundwater storage and recharge in the West. Here we assess the impact of projected changes in climate on groundwater recharge in the near (2021-2050) and far (2071-2100) future across the western U.S. Variable Infiltration Capacity model was run with RCP 6.0 forcing from 11 global climate models and "subsurface runoff" output was considered as recharge. Recharge is expected to decrease in the West (-5.8 ± 14.3%) and Southwest (-4.0 ± 6.7%) regions in the near future and in the South region (-9.5 ± 24.3%) in the far future. The Northern Rockies region is expected to get more recharge in the near (+5.3 ± 9.2%) and far (+11.8 ± 12.3%) future. Overall, southern portions of the western U.S. are expected to get less recharge in the future and northern portions will get more. Climate change interacts with land surface properties to affect the amount of recharge that occurs in the future. Effects on recharge due to change in vegetation response from projected changes in climate and CO2 concentration, though important, are not considered in this study.

Review: Recharge rates and chemistry beneath playas of the High Plains aquifer, USA

NASA Astrophysics Data System (ADS)

Gurdak, Jason J.; Roe, Cassia D.

2010-12-01

Playas are ephemeral, closed-basin wetlands that are hypothesized as an important source of recharge to the High Plains aquifer in central USA. The ephemeral nature of playas, low regional recharge rates, and a strong reliance on groundwater from the High Plains aquifer has prompted many questions regarding the contribution and quality of recharge from playas to the High Plains aquifer. As a result, there has been considerable scientific debate about the potential for water to infiltrate the relatively impermeable playa floors, travel through the unsaturated zone sediments that are tens of meters thick, and subsequently recharge the High Plains aquifer. This critical review examines previously published studies on the processes that control recharge rates and chemistry beneath playas. Reported recharge rates beneath playas range from less than 1.0 to more than 500 mm/yr and are generally 1-2 orders of magnitude higher than recharge rates beneath interplaya settings. Most studies support 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 review provide science-based implications for management of playas and groundwater resources of the High Plains aquifer and directions for future research.

Groundwater recharge in desert playas: current rates and future effects of climate change

NASA Astrophysics Data System (ADS)

McKenna, Owen P.; Sala, Osvaldo E.

2018-01-01

Our results from playas, which are topographic low areas situated in closed-catchments in drylands, indicated that projected climate change in Southwestern USA would have a net positive impact over runon and groundwater recharge beneath playas. Expected increased precipitation variability can cause up to a 300% increase in annual groundwater recharge beneath playas. This increase will overshadow the effect of decreased precipitation amount that could cause up to a 50% decrease in recharge beneath playas. These changes could have a significant impact on groundwater and carbon storage. These results are important given that groundwater resources in Southwestern USA continue to decline due to human consumption outpacing natural recharge of aquifers. Here, we report on groundwater recharge rates ranging from less than 1 mm to greater than 25 mm per year beneath desert playas. Playas located in larger and steeper catchments with finer-textured soils had the highest rates of recharge. Vegetation cover had no effect on recharge beneath playas. We modeled catchment runoff generation and found that the amount of runon a playa receives annually strongly correlated to the rate of groundwater recharge beneath that playa. Runon occurred during precipitation events larger than 20 mm and increased linearly with events above that threshold.

Design and Testing of a Transcutaneous RF Recharging System for a Fetal Micropacemaker.

PubMed

Vest, Adriana N; Zhou, Li; Huang, Xuechen; Norekyan, Viktoria; Bar-Cohen, Yaniv; Chmait, Ramen H; Loeb, Gerald Eli

2017-04-01

We have developed a rechargeable fetal micropacemaker in order to treat severe fetal bradycardia with comorbid hydrops fetalis. The necessarily small form factor of the device, small patient population, and fetal anatomy put unique constraints on the design of the recharging system. To overcome these constraints, a custom high power field generator was built and the recharging process was controlled by utilizing pacing rate as a measure of battery state, a feature of the relaxation oscillator used to generate stimuli. The design and in vitro and in vivo verification of the recharging system is presented here, showing successful generation of recharging current in a fetal lamb model.

Design and Testing of a Transcutaneous RF Recharging System for a Fetal Micropacemaker

PubMed Central

Vest, Adriana N.; Zhou, Li; Huang, Xuechen; Norekyan, Viktoria; Bar-Cohen, Yaniv; Chmait, Ramen H.; Loeb, Gerald Eli

2017-01-01

We have developed a rechargeable fetal micropacemaker in order to treat severe fetal bradycardia with comorbid hydrops fetalis. The necessarily small form factor of the device, small patient population, and fetal anatomy put unique constraints on the design of the recharging system. To overcome these constraints, a custom high power field generator was built and the recharging process was controlled by utilizing pacing rate as a measure of battery state, a feature of the relaxation oscillator used to generate stimuli. The design and in vitro and in vivo verification of the recharging system is presented here, showing successful generation of recharging current in a fetal lamb model. PMID:28212097

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.

Mechanisms of recharge in a fractured porous rock aquifer in a semi-arid region

NASA Astrophysics Data System (ADS)

Manna, Ferdinando; Walton, Kenneth M.; Cherry, John A.; Parker, Beth L.

2017-12-01

Eleven porewater profiles in rock core from an upland exposed sandstone vadose zone in southern California, with thickness varying between 10 and 62 m, were analyzed for chloride (Cl) concentration to examine recharge mechanisms, estimate travel times in the vadose zone, assess spatial and temporal variability of recharge, and determine effects of land use changes on recharge. As a function of their location and the local terrain, the profiles were classified into four groups reflecting the range of site characteristics. Century- to millennium-average recharge varied from 4 to 23 mm y-1, corresponding to <1-5% of the average annual precipitation (451 mm over the 1878-2016 period). Based on the different average Cl concentrations in the vadose zone and in groundwater, the contribution of diffuse flow (estimated at 80%) and preferential flow (20%) to the total recharge was quantified. This model of dual porosity recharge was tested by simulating transient Cl transport along a physically based narrow column using a discrete fracture-matrix numerical model. Using a new approach based on partitioning both water and Cl between matrix and fracture flow, porewater was dated and vertical displacement rates estimated to range in the sandstone matrix from 3 to 19 cm y-1. Moreover, the temporal variability of recharge was estimated and, along each profile, past recharge rates calculated based on the sequence of Cl concentrations in the vadose zone. Recharge rates increased at specific times coincident with historical changes in land use. The consistency between the timing of land use modifications and changes in Cl concentration and the match between observed and simulated Cl concentration values in the vadose zone provide confidence in porewater age estimates, travel times, recharge estimates, and reconstruction of recharge histories. This study represents an advancement of the application of the chloride mass balance method to simultaneously determine recharge mechanisms and

Induced recharge of an artesian glacial-drift aquifer at Kalamazoo, Michigan

USGS Publications Warehouse

Reed, J.E.; Deutsch, Morris; Wiitala, S.W.

1966-01-01

As part of a program for managing its ground-water supply, the city of Kalamazoo has constructed induced-recharge facilities at the sites of several of its well fields. To determine the benefits of induced recharge in a water-management program, the U.S. Geological Survey, in cooperation with the city, conducted a series of field experiments at a city well field (Station 9). The 12 production wells at the test site penetrate about 160 feet of glacial drift, which can be separated into three general units a lower aquifer, an intervening confining layer, and an upper aquifer. Although the upper aquifer is not tapped by any of the municipal supply wells, it serves as a storage and transmission medium for water from the West Fork Portage Creek. The testing program consisted of four aquifer and three recharge tests. The aquifer tests show that the transmissibility of the upper and lower aquifers ranges from 50,000 to 100,000 gallons per day per foot and indicate that nearly 200 gpm (gallons per minute) leaks through the intervening aquiclude under nonpumping conditions. The object of the three recharge tests (tests 5, 6, and 7) was to observe the effects of induced recharge by varying conditions in the recharge channel. During the three recharge tests, 7 wells were pumped at a total rate averaging about 2,500 gpm. During test 5, inflow to the channel was shut off, and the water level in the channel was allowed to decline. Drawdowns measured during this test were used as a standard for comparison with drawdowns in tests 6 and 7. During test 6, the head in the recharge channel was maintained as constant as possible, and the inflow to the channel was measured. The rate of induced recharge, as indicated by the measured inflow, averaged about 300 gpm. Between tests 6 and 7, the area of the channel was increased from 27,000 to 143,000 square feet. During test 7, the head in the channel was again maintained as constant as possible, but the inflow to the larger channel

Solar recharging system for hearing aid cells.

PubMed

Gòmez Estancona, N; Tena, A G; Torca, J; Urruticoechea, L; Muñiz, L; Aristimuño, D; Unanue, J M; Torca, J; Urruticoechea, A

1994-09-01

We present a solar recharging system for nickel-cadmium cells of interest in areas where batteries for hearing aids are difficult to obtain. The charger has sun cells at the top. Luminous energy is converted into electrical energy, during the day and also at night if there is moonlight. The cost of the charger and hearing aid is very low at 35 US$. The use of solar recharging for hearing aids would be useful in alleviating the problems of deafness in parts of developing countries where there is no electricity.

Ecohydrologic process modeling of mountain block groundwater recharge.

PubMed

Magruder, Ian A; Woessner, William W; Running, Steve W

2009-01-01

Regional mountain block recharge (MBR) is a key component of alluvial basin aquifer systems typical of the western United States. Yet neither water scientists nor resource managers have a commonly available and reasonably invoked quantitative method to constrain MBR rates. Recent advances in landscape-scale ecohydrologic process modeling offer the possibility that meteorological data and land surface physical and vegetative conditions can be used to generate estimates of MBR. A water balance was generated for a temperate 24,600-ha mountain watershed, elevation 1565 to 3207 m, using the ecosystem process model Biome-BGC (BioGeochemical Cycles) (Running and Hunt 1993). Input data included remotely sensed landscape information and climate data generated with the Mountain Climate Simulator (MT-CLIM) (Running et al. 1987). Estimated mean annual MBR flux into the crystalline bedrock terrain is 99,000 m(3) /d, or approximately 19% of annual precipitation for the 2003 water year. Controls on MBR predictions include evapotranspiration (radiation limited in wet years and moisture limited in dry years), soil properties, vegetative ecotones (significant at lower elevations), and snowmelt (dominant recharge process). The ecohydrologic model is also used to investigate how climatic and vegetative controls influence recharge dynamics within three elevation zones. The ecohydrologic model proves useful for investigating controls on recharge to mountain blocks as a function of climate and vegetation. Future efforts will need to investigate the uncertainty in the modeled water balance by incorporating an advanced understanding of mountain recharge processes, an ability to simulate those processes at varying scales, and independent approaches to calibrating MBR estimates. Copyright © 2009 The Author(s). Journal compilation © 2009 National Ground Water Association.

A synopsis of climate change effects on groundwater recharge

NASA Astrophysics Data System (ADS)

Smerdon, Brian D.

2017-12-01

Six review articles published between 2011 and 2016 on groundwater and climate change are briefly summarized. This synopsis focuses on aspects related to predicting changes to groundwater recharge conditions, with several common conclusions between the review articles being noted. The uncertainty of distribution and trend in future precipitation from General Circulation Models (GCMs) results in varying predictions of recharge, so much so that modelling studies are often not able to predict the magnitude and direction (increase or decrease) of future recharge conditions. Evolution of modelling approaches has led to the use of multiple GCMs and hydrologic models to create an envelope of future conditions that reflects the probability distribution. The choice of hydrologic model structure and complexity, and the choice of emissions scenario, has been investigated and somewhat resolved; however, recharge results remain sensitive to downscaling methods. To overcome uncertainty and provide practical use in water management, the research community indicates that modelling at a mesoscale, somewhere between watersheds and continents, is likely ideal. Improvements are also suggested for incorporating groundwater processes within GCMs.

Hydrodynamic characteristics of the western Doñana Region (area of El Abalario), Huelva, Spain

NASA Astrophysics Data System (ADS)

Trick, Thomas; Custodio, Emilio

èle a été calé en utilisant d'une part les valeurs des paramètres hydrauliques obtenus par des essais de pompage et d'après les données piezométriques mesurées à différentes profondeurs, et d'autre part l'apport estimé de la ravine de La Rocina. L'écoulement d'eau souterraine s'effectue par drainage latérale dans trois directions, d'une part vers la côte, d'autre part à travers la ravine de La Rocina et finalement directement vers les Marais de Doñana situés à l'est et sud-est dans le delta du fleuve Guadalquivir. Avec une pluviométrie moyenne comprise entre 550 et 600 mm, la recharge nette moyenne annuelle des nappes, pour des périodes de temps assez longues, est estimée entre 100 et 200 mm dans les aires de végétation autochtone, et elle est nettement inférieure dans les aires plantées deucalyptus. Le modèle transitoire montre que la recharge varie dans l'espace et qu'elle n'est pas clairement proportionnelle aux précipitations annuelles. L'évapotranspiration phréatique joue un rôle important et diminue la valeur nette de la recharge des nappes de 0,4 à 0,6 de la valeur calculée avec un modèle de bilan d'eau dans le sol. La section modélisée est utilisée pour étudier l'effet de l'extraction d'eau souterraine sur la profondeur du niveau phréatique en soustrayant le flux vertical, calculé grâce à une formule d'hydraulique des puits, de la nappe profonde semi-confinée. Le résultat de cette extraction est une diminution de l'évapotranspiration phréatique, du flux au niveau de la ravine de La Rocina et de la fréquence d'inondation des lagunes. La substitution de forêts d'eucalyptus par de la végétation autochtone peut permettre la remonté des niveaux phréatiques et même réactiver d'anciens ravins affluents à La Rocina. La región de Doñana, situada en el sudoeste de España, incluye una gran e importante reserva natural, cuyos humedales están siendo afectados por la actividad humana. La extensa plantación de

Importance of unsaturated zone flow for simulating recharge in a humid climate

USGS Publications Warehouse

Hunt, R.J.; Prudic, David 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.

The Effect of modeled recharge distribution on simulated groundwater availability and capture

USGS Publications Warehouse

Tillman, Fred D.; Pool, Donald R.; Leake, Stanley A.

2015-01-01

Simulating groundwater flow in basin-fill aquifers of the semiarid southwestern United States commonly requires decisions about how to distribute aquifer recharge. Precipitation can recharge basin-fill aquifers by direct infiltration and transport through faults and fractures in the high-elevation areas, by flowing overland through high-elevation areas to infiltrate at basin-fill margins along mountain fronts, by flowing overland to infiltrate along ephemeral channels that often traverse basins in the area, or by some combination of these processes. The importance of accurately simulating recharge distributions is a current topic of discussion among hydrologists and water managers in the region, but no comparative study has been performed to analyze the effects of different recharge distributions on groundwater simulations. This study investigates the importance of the distribution of aquifer recharge in simulating regional groundwater flow in basin-fill aquifers by calibrating a groundwater-flow model to four different recharge distributions, all with the same total amount of recharge. Similarities are seen in results from steady-state models for optimized hydraulic conductivity values, fit of simulated to observed hydraulic heads, and composite scaled sensitivities of conductivity parameter zones. Transient simulations with hypothetical storage properties and pumping rates produce similar capture rates and storage change results, but differences are noted in the rate of drawdown at some well locations owing to the differences in optimized hydraulic conductivity. Depending on whether the purpose of the groundwater model is to simulate changes in groundwater levels or changes in storage and capture, the distribution of aquifer recharge may or may not be of primary importance.

The Effects of Ashe Juniper on Groundwater Recharge in the Edwards Aquifer

NASA Astrophysics Data System (ADS)

Bazan, R. A.; Wilcox, B. P.; Munster, C. L.; Gregory, L. F.

2008-12-01

Understanding groundwater recharge rates has direct relevance for management of the Edwards Aquifer, which serves as the main source of fresh water for the city of San Antonio and surrounding communities. As population around San Antonio continues to grow, so does the demand for water and the stress placed on the aquifer. A method that is commonly believed to augment water yields is brush management. Recently on the Edwards Plateau decreasing streamflow has coincided with increasing juniper density. This has led many to believe that removing juniper would increase available water. Due to its karstic nature, the recharge zone of the Edwards Aquifer is assumed to be a prime location for augmenting water yields through vegetation manipulation. This study assesses the dynamics of recharge and the effects of manipulating surface vegetation. To accomplish this, a shallow cave located in the Edwards Aquifer recharge zone in San Antonio, Texas was instrumented to monitor drip recharge in response to simulated rainfall events. In 2004, simulations were conducted over the cave to measure recharge rates with a dense Ashe juniper canopy. The data and observations from the initial simulations were used to establish a baseline with the juniper in place. In March 2008 the juniper stand was cleared and the rainfall simulations were reproduced in June and July 2008. Results initially indicated that removing the juniper decreases recharge, however, surface runoff was significantly increased. From the results we can conclude that the dynamics of recharge are affected initially following removal of juniper.

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.

Impact of recharge water temperature on bioclogging during managed aquifer recharge: a laboratory study

NASA Astrophysics Data System (ADS)

Xia, Lu; Gao, Zongjun; Zheng, Xilai; Wei, Jiuchuan

2018-04-01

To investigate the effect of recharge water temperature on bioclogging processes and mechanisms during seasonal managed aquifer recharge (MAR), two groups of laboratory percolation experiments were conducted: a winter test and a summer test. The temperatures were controlled at 5±2 and 15±3 °C, and the tests involved bacterial inoculums acquired from well water during March 2014 and August 2015, for the winter and summer tests, respectively. The results indicated that the sand columns clogged 10 times faster in the summer test due to a 10-fold larger bacterial growth rate. The maximum concentrations of total extracellular polymeric substances (EPS) in the winter test were approximately twice those in the summer test, primarily caused by a 200 μg/g sand increase of both loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS). In the first half of the experimental period, the accumulation of bacteria cells and EPS production induced rapid bioclogging in both the winter and summer tests. Afterward, increasing bacterial growth dominated the bioclogging in the summer test, while the accumulation of LB-EPS led to further bioclogging in the winter test. The biological analysis determined that the dominant bacteria in experiments for both seasons were different and the bacterial community diversity was 50% higher in the winter test than that for summer. The seasonal inoculums could lead to differences in the bacterial community structure and diversity, while recharge water temperature was considered to be a major factor influencing the bacterial growth rate and metabolism behavior during the seasonal bioclogging process.

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.

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.

Ground-water-recharge rates in Nassau and Suffolk counties, New York

USGS Publications Warehouse

Peterson, D.S.

1987-01-01

Groundwater is the sole source of freshwater in Nassau and Suffolk Counties on Long Island; therefore, the rate at which precipitation replenishes the groundwater system may affect future water supplies in some areas. Annual precipitation on Long Island averages 45 inches per year, but less than 23 inches , or 50%, recharges the ground-water system. (Recharge is precipitation that percolates to the ground-water system naturally; it does not include water from stormwater basins or injection wells.) The rate of recharge varies locally and ranges from 29% to 57% of precipitation, depending on land use, season, and amount of storm sewering in the area. Recharge was calculated by subtracting evapotranspiration and direct runoff values from known precipitation values. Evapotranspiration was calculated by the Thornwaite and Mather method, and direct runoff rates to streams were calculated from streamflow records and size of known storm-sewer service areas. This report includes maps that depict precipitation, evapotranspiration, and rates of natural recharge in Nassau and Suffolk Counties for use in future hydrologic studies on Long Island. (Author 's abstract)

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.

Groundwater Recharge Processes Revealed By Multi-Tracers Approach in a Headwater, North China Plain

NASA Astrophysics Data System (ADS)

Sakakibara, K.; Tsujimura, M.; Song, X.; Zhang, J.

2014-12-01

Groundwater recharge variation in space and time is crucial for effective water management especially in arid/ semi-arid regions. In order to reveal comprehensive groundwater recharge processes in a catchment with a large topographical relief and seasonal hydrological variations, intensive field surveys were conducted at 4 times in different seasons in Wangkuai watershed, Taihang Mountains, which is a main groundwater recharge zone of North China Plain. The groundwater, spring, stream water and lake water were sampled, and inorganic solute constituents and stable isotopes of oxygen-18 and deuterium were determined on all water samples. Also, the stream flow rate was observed in stable state condition. The stable isotopic compositions, silica and bicarbonate concentrations in the groundwater show close values as those in the surface water, suggesting main groundwater recharge occurs from surface water at mountain-plain transitional zone throughout a year. Also, the deuterium and oxgen-18 in the Wangkuai reservoir and the groundwater in the vicinity of the reservoir show higher values, suggesting the reservoir water, affected by evaporation effect, seems to have an important role for the groundwater recharge in alluvial plain. For specifying the groundwater recharge area and quantifying groundwater recharge rate from the reservoir, an inversion analysis and a simple mixing model were applied in Wangkuai watershed using stable isotopes of oxygen-18 and deuterium. The model results show that groundwater recharge occurs dominantly at the altitude from 357 m to 738 m corresponding to mountain-plain transitional zone, and groundwater recharge rate by Wangkuai reservoir is estimated to be 2.4 % of total groundwater recharge in Wangkuai watershed.

The effect of modeled recharge distribution on simulated groundwater availability and capture.

PubMed

Tillman, F D; Pool, D R; Leake, S A

2015-01-01

Simulating groundwater flow in basin-fill aquifers of the semiarid southwestern United States commonly requires decisions about how to distribute aquifer recharge. Precipitation can recharge basin-fill aquifers by direct infiltration and transport through faults and fractures in the high-elevation areas, by flowing overland through high-elevation areas to infiltrate at basin-fill margins along mountain fronts, by flowing overland to infiltrate along ephemeral channels that often traverse basins in the area, or by some combination of these processes. The importance of accurately simulating recharge distributions is a current topic of discussion among hydrologists and water managers in the region, but no comparative study has been performed to analyze the effects of different recharge distributions on groundwater simulations. This study investigates the importance of the distribution of aquifer recharge in simulating regional groundwater flow in basin-fill aquifers by calibrating a groundwater-flow model to four different recharge distributions, all with the same total amount of recharge. Similarities are seen in results from steady-state models for optimized hydraulic conductivity values, fit of simulated to observed hydraulic heads, and composite scaled sensitivities of conductivity parameter zones. Transient simulations with hypothetical storage properties and pumping rates produce similar capture rates and storage change results, but differences are noted in the rate of drawdown at some well locations owing to the differences in optimized hydraulic conductivity. Depending on whether the purpose of the groundwater model is to simulate changes in groundwater levels or changes in storage and capture, the distribution of aquifer recharge may or may not be of primary importance. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

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.

Assessment of groundwater recharge in an ash-fall mantled karst aquifer of southern Italy

NASA Astrophysics Data System (ADS)

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

2014-12-01

In southern Italy, Mesozoic carbonate formations, covered by ash-fall pyroclastic soils, are large karst aquifers and major groundwater resources. For these aquifers, even though Allocca et al., 2014 estimated a mean annual groundwater recharge coefficient at regional scale, a more complete understanding of the recharge processes at small spatio-temporal scale is a primary scientific target. In this paper, we study groundwater recharge processes in the Acqua della Madonna test site (Allocca et al., 2008) through the integrated analysis of piezometric levels, rainfall, soil moisture and air temperature data. These were gathered with hourly frequency by a monitoring station in 2008. We applied the Episodic Master Recharge method (Nimmo et al., 2014) to identify episodes of recharge and estimate the Recharge to Precipitation Ratio (RPR) at both the individual-episode and annual time scales. For different episodes of recharge observed, RPR ranges from 97% to 37%, with an annual mean around 73%. This result has been confirmed by a soil water balance and the application of the Thornthwaite-Mather method to estimate actual evapotranspiration. Even though it seems higher than RPRs typical of some parts of the world, it is very close to the mean annual groundwater recharge coefficient estimated at the regional scale for the karst aquifers of southern Italy. In addition, the RPR is affected at the daily scale by both antecedent soil moisture and rainfall intensity, as demonstrated by a statistically significant multiple linear regression among such hydrological variables. In particular, the recharge magnitude is great for low storm intensity and high antecedent soil moisture value. The results advance the comprehension of groundwater recharge processes in karst aquifers, and the sensitivity of RPR to antecedent soil moisture and rainfall intensity facilitates the prediction of the influence of climate and precipitation regime change on the groundwater recharge process.

Climate variability and vadose zone controls on damping of transient recharge

USGS Publications Warehouse

Corona, Claudia R.; Gurdak, Jason J.; Dickinson, Jesse; Ferré, T.P.A.; Maurer, Edwin P.

2018-01-01

Increasing demand on groundwater resources motivates understanding of the controls on recharge dynamics so model predictions under current and future climate may improve. Here we address questions about the nonlinear behavior of flux variability in the vadose zone that may explain previously reported teleconnections between global-scale climate variability and fluctuations in groundwater levels. We use hundreds of HYDRUS-1D simulations in a sensitivity analysis approach to evaluate the damping depth of transient recharge over a range of periodic boundary conditions and vadose zone geometries and hydraulic parameters that are representative of aquifer systems of the conterminous United States (U.S). Although the models were parameterized based on U.S. aquifers, findings from this study are applicable elsewhere that have mean recharge rates between 3.65 and 730 mm yr–1. We find that mean infiltration flux, period of time varying infiltration, and hydraulic conductivity are statistically significant predictors of damping depth. The resulting framework explains why some periodic infiltration fluxes associated with climate variability dampen with depth in the vadose zone, resulting in steady-state recharge, while other periodic surface fluxes do not dampen with depth, resulting in transient recharge. We find that transient recharge in response to the climate variability patterns could be detected at the depths of water levels in most U.S. aquifers. Our findings indicate that the damping behavior of transient infiltration fluxes is linear across soil layers for a range of texture combinations. The implications are that relatively simple, homogeneous models of the vadose zone may provide reasonable estimates of the damping depth of climate-varying transient recharge in some complex, layered vadose zone profiles.

High-performance rechargeable batteries with fast solid-state ion conductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farmer, Joseph C.

A high-performance rechargeable battery using ultra-fast ion conductors. In one embodiment the rechargeable battery apparatus includes an enclosure, a first electrode operatively connected to the enclosure, a second electrode operatively connected to the enclosure, a nanomaterial in the enclosure, and a heat transfer unit.

Groundwater recharge estimation under semi arid climate: Case of Northern Gafsa watershed, Tunisia

NASA Astrophysics Data System (ADS)

Melki, Achraf; Abdollahi, Khodayar; Fatahi, Rouhallah; Abida, Habib

2017-08-01

Natural groundwater recharge under semi arid climate, like rainfall, is subjected to large variations in both time and space and is therefore very difficult to predict. Nevertheless, in order to set up any strategy for water resources management in such regions, understanding the groundwater recharge variability is essential. This work is interested in examining the impact of rainfall on the aquifer system recharge in the Northern Gafsa Plain in Tunisia. The study is composed of two main parts. The first is interested in the analysis of rainfall spatial and temporal variability in the study basin while the second is devoted to the simulation of groundwater recharge. Rainfall analysis was performed based on annual precipitation data recorded in 6 rainfall stations over a period of 56 years (1960-2015). Potential evapotranspiration data were also collected from 1960 to 2011 (52 years). The hydrologic distributed model WetSpass was used for the estimation of groundwater recharge. Model calibration was performed based on an assessment of the agreement between the sum of recharge and runoff values estimated by the WetSpass hydrological model and those obtained by the climatic method. This latter is based on the difference calculated between rainfall and potential evapotranspiration recorded at each rainy day. Groundwater recharge estimation, on monthly scale, showed that average annual precipitation (183.3 mm/year) was partitioned to 5, 15.3, 36.8, and 42.8% for interception, runoff, actual evapotranspiration and recharge respectively.

Factors influencing ground-water recharge in the eastern United States

USGS Publications Warehouse

Nolan, B.T.; Healy, R.W.; Taber, P.E.; Perkins, K.; Hitt, K.J.; Wolock, D.M.

2007-01-01

Ground-water recharge estimates for selected locations in the eastern half of the United States were obtained by Darcian and chloride-tracer methods and compared using statistical analyses. Recharge estimates derived from unsaturated-zone (RUZC) and saturated-zone (RSZC) chloride mass balance methods are less variable (interquartile ranges or IQRs are 9.5 and 16.1 cm/yr, respectively) and more strongly correlated with climatic, hydrologic, land use, and sediment variables than Darcian estimates (IQR = 22.8 cm/yr). The unit-gradient Darcian estimates are a nonlinear function of moisture content and also reflect the uncertainty of pedotransfer functions used to estimate hydraulic parameters. Significance level is 0.3. Estimates of RSZC were evaluated using analysis of variance, multiple comparison tests, and an exploratory nonlinear regression (NLR) model. Recharge generally is greater in coastal plain surficial aquifers, fractured crystalline rocks, and carbonate rocks, or in areas with high sand content. Westernmost portions of the study area have low recharge, receive somewhat less precipitation, and contain fine-grained sediment. The NLR model simulates water input to the land surface followed by transport to ground water, depending on factors that either promote or inhibit water infiltration. The model explains a moderate amount of variation in the data set (coefficient of determination = 0.61). Model sensitivity analysis indicates that mean annual runoff, air temperature, and precipitation, and an index of ground-water exfiltration potential most influence estimates of recharge at sampled sites in the region. Soil characteristics and land use have less influence on the recharge estimates, but nonetheless are significant in the NLR model. ?? 2006 Elsevier B.V. All rights reserved.

Anode-Free Rechargeable Lithium Metal Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qian, Jiangfeng; Adams, Brian D.; Zheng, Jianming

2016-08-18

Anode-free rechargeable lithium (Li) batteries (AFLBs) are phenomenal energy storage systems due to their significantly increased energy density and reduced cost relative to Li-ion batteries, as well as ease of assembly owing to the absence of an active (reactive) anode material. However, significant challenges, including Li dendrite growth and low cycling Coulombic efficiency (CE), have prevented their practical implementation. Here, we report for the first time an anode-free rechargeable lithium battery based on a Cu||LiFePO4 cell structure with an extremely high CE (> 99.8%). This results from the utilization of both an exceptionally stable electrolyte and optimized charge/discharge protocols whichmore » minimize the corrosion of the in-situ formed Li metal anode.« less

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.

Exploratory Development of an Electrically Rechargeable Lithium Battery.

DTIC Science & Technology

1980-10-01

RECHARGEABLE LITHIUM BATTERY O K. M. Abraham GtJ. L. Goldman ~M. D. Dempsey MCG. L. Holleck EIC Laboratories, Inc. " - 55 Chapel Street Newton, MA 02158 October...COVERED (, Epl.oratory Development of an Electrically 7 9FINAL REPORT- 7-2-79 to 7-1-80 Rechargeable Lithium Battery * .. PFORMIN ORO. RE RT NUMBER 7...Bloek 20, Il diiItrent hurm Reprt) I. SUPPLEMENTARY NOTES IS. KEY WORDS (Continue n Mrverse side It necesary and identify by block number) Vanadium

Enhanced recharge and karst, Edwards aquifer, south central Texas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hammond, W.W. Jr.

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 ofmore » 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.« less

Design and construction of a dual recharge system at Minot, North Dakota

USGS Publications Warehouse

Pettyjohn, Wayne A.

1968-01-01

In 1965, a ground-water recharge facility was constructed and placed in operation to forestall an impending water shortage at Minot, North Dakota. The facility is unique in that the rate of recharge to a buried sand and gravel aquifer is augmented by perforating an overlying bed of clay using hydraulic connectors (gravel-filled bored holes) in conjunction with an open-pit excavation. The connectors were drilled by typical well-boring techniques and the open pit was excavated by common construction methods. The recharge technique made it possible to add about million gallons per day of water to underground storage with a total capital investment of about $200,000. The alternative originally proposed was a 50-mile long pipeline to Garrison Reservoir, at a 1959 estimated cost of $12,000,000. The recharge technique employed at Minot should have wide application in the ground-water industry in areas where natural recharge to permeable deposits is impeded by overlying beds of low permeability.

Focused ground-water recharge in the Amargosa Desert basin: Chapter E in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

USGS Publications Warehouse

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

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 Niño 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

Groundwater recharge and sustainability in the High Plains aquifer in Kansas, USA

USGS Publications Warehouse

Sophocleous, M.

2005-01-01

Sustainable use of groundwater must ensure not only that the future resource is not threatened by overuse, but also that natural environments that depend on the resource, such as stream baseflows, riparian vegetation, aquatic ecosystems, and wetlands are protected. To properly manage groundwater resources, accurate information about the inputs (recharge) and outputs (pumpage and natural discharge) within each groundwater basin is needed so that the long-term behavior of the aquifer and its sustainable yield can be estimated or reassessed. As a first step towards this effort, this work highlights some key groundwater recharge studies in the Kansas High Plains at different scales, such as regional soil-water budget and groundwater modeling studies, county-scale groundwater recharge studies, as well as field-experimental local studies, including some original new findings, with an emphasis on assumptions and limitations as well as on environmental factors affecting recharge processes. The general impact of irrigation and cultivation on recharge is to appreciably increase the amount of recharge, and in many cases to exceed precipitation as the predominant source of recharge. The imbalance between the water input (recharge) to the High Plains aquifer and the output (pumpage and stream baseflows primarily) is shown to be severe, and responses to stabilize the system by reducing water use, increasing irrigation efficiency, adopting water-saving land-use practices, and other measures are outlined. Finally, the basic steps necessary to move towards sustainable use of groundwater in the High Plains are delineated, such as improving the knowledge base, reporting and providing access to information, furthering public education, as well as promoting better understanding of the public's attitudinal motivations; adopting the ecosystem and adaptive management approaches to managing groundwater; further improving water efficiency; exploiting the full potential of dryland and

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.

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

Vecteurs Singuliers des Theories des Champs Conformes Minimales

NASA Astrophysics Data System (ADS)

Benoit, Louis

En 1984 Belavin, Polyakov et Zamolodchikov revolutionnent la theorie des champs en explicitant une nouvelle gamme de theories, les theories quantiques des champs bidimensionnelles invariantes sous les transformations conformes. L'algebre des transformations conformes de l'espace-temps presente une caracteristique remarquable: en deux dimensions elle possede un nombre infini de generateurs. Cette propriete impose de telles conditions aux fonctions de correlations qu'il est possible de les evaluer sans aucune approximation. Les champs des theories conformes appartiennent a des representations de plus haut poids de l'algebre de Virasoro, une extension centrale de l'algebre conforme du plan. Ces representations sont etiquetees par h, le poids conforme de leur vecteur de plus haut poids, et par la charge centrale c, le facteur de l'extension centrale, commune a toutes les representations d'une meme theorie. Les theories conformes minimales sont constituees d'un nombre fini de representations. Parmi celles-ci se trouvent des theories unitaires dont les representation forment la serie discrete de l'algebre de Virasoro; leur poids h a la forme h_{p,q}(m)=[ (p(m+1) -qm)^2-1] (4m(m+1)), ou p,q et m sont des entiers positifs et p+q<= m+1. L'entier m parametrise la charge centrale: c(m)=1 -{6over m(m+1)} avec n>= 2. Ces representations possedent un sous-espace invariant engendre par deux sous-representations avec h_1=h_{p,q} + pq et h_2=h_{p,q} + (m-p)(m+1-q) dont chacun des vecteurs de plus haut poids portent le nom de vecteur singulier et sont notes respectivement |Psi _{p,q}> et |Psi_{m-p,m+1-q}>. . Les theories super-conformes sont une version super-symetrique des theories conformes. Leurs champs appartiennent a des representation de plus haut poids de l'algebre de Neveu-Schwarz, une des deux extensions super -symetriques de l'algebre de Virasoro. Les theories super -conformes minimales possedent la meme structure que les theories conformes minimales. Les representations

Overview of ground-water recharge study sites

USGS Publications Warehouse

Constantz, Jim; Adams, Kelsey S.; Stonestrom, David A.; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley 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 Niño climatic pattern (1997–1998) to drier than normal conditions associated with a La Niña climatic pattern marked by unprecedented warmth in the western tropical Pacific and Indian Oceans (1998–2002). The strong El Niño 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

Effect of irrigation return flow on groundwater recharge in an overexploited aquifer in Bangladesh

NASA Astrophysics Data System (ADS)

Touhidul Mustafa, Syed Md.; Shamsudduha, Mohammad; Huysmans, Marijke

2016-04-01

Irrigated agriculture has an important role in the food production to ensure food security of Bangladesh that is home to over 150 million people. However, overexploitation of groundwater for irrigation, particularly during the dry season, causes groundwater-level decline in areas where abstraction is high and surface geology inhibits direct recharge to underlying shallow aquifer. This is causing a number of potential adverse socio-economic, hydrogeological, and environmental problems in Bangladesh. Alluvial aquifers are primarily recharged during monsoon season from rainfall and surface sources. However, return flow from groundwater-fed irrigation can recharge during the dry months. Quantification of the effect of return flow from irrigation in the groundwater system is currently unclear but thought to be important to ensure sustainable management of the overexploited aquifer. The objective of the study is to investigate the effect of irrigation return flow on groundwater recharge in the north-western part of Bangladesh, also known as Barind Tract. A semi-physically based distributed water balance model (WetSpass-M) is used to simulate spatially distributed monthly groundwater recharge. Results show that, groundwater abstraction for irrigation in the study area has increased steadily over the last 29 years. During the monsoon season, local precipitation is the controlling factor of groundwater recharge; however, there is no trend in groundwater recharge during that period. During the dry season, however, irrigation return-flow plays a major role in recharging the aquifer in the irrigated area compared to local precipitation. Therefore, during the dry season, mean seasonal groundwater recharge has increased and almost doubled over the last 29 years as a result of increased abstraction for irrigation. The increase in groundwater recharge during dry season has however no significant effect in the improvement of groundwater levels. The relation between groundwater

Use of environmental isotope tracer and GIS techniques to estimate basin recharge

NASA Astrophysics Data System (ADS)

Odunmbaku, Abdulganiu A. A.

The extensive use of ground water only began with the advances in pumping technology at the early portion of 20th Century. Groundwater provides the majority of fresh water supply for municipal, agricultural and industrial uses, primarily because of little to no treatment it requires. Estimating the volume of groundwater available in a basin is a daunting task, and no accurate measurements can be made. Usually water budgets and simulation models are primarily used to estimate the volume of water in a basin. Precipitation, land surface cover and subsurface geology are factors that affect recharge; these factors affect percolation which invariably affects groundwater recharge. Depending on precipitation, soil chemistry, groundwater chemical composition, gradient and depth, the age and rate of recharge can be estimated. This present research proposes to estimate the recharge in Mimbres, Tularosa and Diablo Basin using the chloride environmental isotope; chloride mass-balance approach and GIS. It also proposes to determine the effect of elevation on recharge rate. Mimbres and Tularosa Basin are located in southern New Mexico State, and extend southward into Mexico. Diablo Basin is located in Texas in extends southward. This research utilizes the chloride mass balance approach to estimate the recharge rate through collection of groundwater data from wells, and precipitation. The data were analysed statistically to eliminate duplication, outliers, and incomplete data. Cluster analysis, piper diagram and statistical significance were performed on the parameters of the groundwater; the infiltration rate was determined using chloride mass balance technique. The data was then analysed spatially using ArcGIS10. Regions of active recharge were identified in Mimbres and Diablo Basin, but this could not be clearly identified in Tularosa Basin. CMB recharge for Tularosa Basin yields 0.04037mm/yr (0.0016in/yr), Diablo Basin was 0.047mm/yr (0.0016 in/yr), and 0.2153mm/yr (0.00848in

Chemical and isotopic methods for quantifying ground-water recharge in a regional, semiarid environment

USGS Publications Warehouse

Wood, Warren W.; Sanford, Ward E.

1995-01-01

The High Plains aquifer underlying the semiarid Southern High Plains of Texas and New Mexico, USA was used to illustrate solute and isotopic methods for evaluating recharge fluxes, runoff, and spatial and temporal distribution of recharge. The chloride mass-balance method can provide, under certain conditions, a time-integrated technique for evaluation of recharge flux to regional aquifers that is independent of physical parameters. Applying this method to the High Plains aquifer of the Southern High Plains suggests that recharge flux is approximately 2% of precipitation, or approximately 11 ± 2 mm/y, consistent with previous estimates based on a variety of physically based measurements. The method is useful because long-term average precipitation and chloride concentrations in rain and ground water have less uncertainty and are generally less expensive to acquire than physically based parameters commonly used in analyzing recharge. Spatial and temporal distribution of recharge was evaluated by use of δ2H, δ18O, and tritium concentrations in both ground water and the unsaturated zone. Analyses suggest that nearly half of the recharge to the Southern High Plains occurs as piston flow through playa basin floors that occupy approximately 6% of the area, and that macropore recharge may be important in the remaining recharge. Tritium and chloride concentrations in the unsaturated zone were used in a new equation developed to quantify runoff. Using this equation and data from a representative basin, runoff was found to be 24 ± 3 mm/y; that is in close agreement with values obtained from water-balance measurements on experimental watersheds in the area. Such geochemical estimates are possible because tritium is used to calculate a recharge flux that is independent of precipitation and runoff, whereas recharge flux based on chloride concentration in the unsaturated zone is dependent upon the amount of runoff. The difference between these two estimates yields the amount

Regional mapping of depression-focussed groundwater recharge incorporating variable topography, climate, and land use

NASA Astrophysics Data System (ADS)

Pavlovskii, I.; Noorduijn, S. L.; Abrakhimova, P.; Bentley, L. R.; Cey, E. E.; Hayashi, M.

2016-12-01

In the water-deficient setting of the Northern Great Plains (or Prairie Pothole Region, PPR), groundwater recharge constitutes only a small fraction of the water budget, meaning that recharge estimates have a high degree of uncertainty. Additionally, recharge primarily occurs as focussed recharge when small topographical depressions are inundated by surface runoff, typically during spring melt while underlying soils are still frozen. This results in a high spatial and temporal variability of recharge rates, which further complicates their evaluation. As part of a major research project called Groundwater Recharge in the Prairies (GRIP), we have developed a soil water balance model to estimate recharge rates at a scale of a single depression and its catchment (< 10 ha). In the next stage of the GRIP project, the present study investigates the possibility of applying this tool for recharge mapping on a regional scale in the Edmonton-Calgary corridor in Alberta, located in the north-western fringe of the PPR. The entire area (49500 km2) was divided into elements based on the proximity to one of 24 Alberta Agriculture weather stations. For each element, the model was run for a series of generic scenarios consisting of representative land use and depression catchment parameters. The latter were constructed using a high-resolution digital elevation model (DEM). The recharge value for each element was then computed using a weighted average of the generic scenario outputs. The new method has a number of benefits. Use of generic scenarios instead of real depressions dramatically reduces computational cost. Extraction of relevant parameters from DEM accounts for depressions which are only flooded sporadically and thus may be absent from the inventories of wet areas based on satellite images. If extra data on topographical parameters become available, the recharge may be recalculated without repeating the entire workflow.

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.

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.

A comparison of recharge rates in aquifers of the United States based on groundwater-age data

USGS Publications Warehouse

McMahon, P.B.; Plummer, Niel; Böhlke, J.K.; Shapiro, S.D.; Hinkle, S.R.

2011-01-01

An overview is presented of existing groundwater-age data and their implications for assessing rates and timescales of recharge in selected unconfined aquifer systems of the United States. Apparent age distributions in aquifers determined from chlorofluorocarbon, sulfur hexafluoride, tritium/helium-3, and radiocarbon measurements from 565 wells in 45 networks were used to calculate groundwater recharge rates. Timescales of recharge were defined by 1,873 distributed tritium measurements and 102 radiocarbon measurements from 27 well networks. Recharge rates ranged from < 10 to 1,200 mm/yr in selected aquifers on the basis of measured vertical age distributions and assuming exponential age gradients. On a regional basis, recharge rates based on tracers of young groundwater exhibited a significant inverse correlation with mean annual air temperature and a significant positive correlation with mean annual precipitation. Comparison of recharge derived from groundwater ages with recharge derived from stream base-flow evaluation showed similar overall patterns but substantial local differences. Results from this compilation demonstrate that age-based recharge estimates can provide useful insights into spatial and temporal variability in recharge at a national scale and factors controlling that variability. Local age-based recharge estimates provide empirical data and process information that are needed for testing and improving more spatially complete model-based methods.

Rechargeable Lithium-Air Batteries: Development of Ultra High Specific Energy Rechargeable Lithium-Air Batteries Based on Protected Lithium Metal Electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-07-01

BEEST Project: PolyPlus is developing the world’s first commercially available rechargeable lithium-air (Li-Air) battery. Li-Air batteries are better than the Li-Ion batteries used in most EVs today because they breathe in air from the atmosphere for use as an active material in the battery, which greatly decreases its weight. Li-Air batteries also store nearly 700% as much energy as traditional Li-Ion batteries. A lighter battery would improve the range of EVs dramatically. Polyplus is on track to making a critical breakthrough: the first manufacturable protective membrane between its lithium–based negative electrode and the reaction chamber where it reacts with oxygenmore » from the air. This gives the battery the unique ability to recharge by moving lithium in and out of the battery’s reaction chamber for storage until the battery needs to discharge once again. Until now, engineers had been unable to create the complex packaging and air-breathing components required to turn Li-Air batteries into rechargeable systems.« less

Hydrogeologic uncertainties and policy implications: The Water Consumer Protection Act of Tucson, Arizona, USA

NASA Astrophysics Data System (ADS)

Wilson, L. G.; Matlock, W. G.; Jacobs, K. L.

confusion entre "infiltration" et "recharge". C'est ainsi que la loi laisse entendre que l'infiltration à partir des lits de rivières le long du champ captant central favorise la recharge de cette zone. En réalité, les différences de perméabilité entre les alluvions du lit et les dépôts sous-jacents remplissant le bassin peuvent provoquer un écoulement sous-jacent. En outre, même si une recharge par l'eau de la rivière Colorado se produit dans cette zone, la nappe sera progressivement salifiée. Les restrictions imposées par la loi quant à l'utilisation de l'eau de la station centrale d'Arizona affectent les quatre outils réglementaires du Code des eaux souterraines de l'Arizona de 1980, en ce qu'ils concernent la zone de gestion active de Tucson: (a) l'augmentation de l'approvisionnement (b) les conditions requises pour les prélèvements d'eau souterraine et les autorisations; (c) les conditions requises pour le plan de gestion, en particulier la pérennité du concessionnaire et les résultats en matière de qualité de l'eau et (d) la condition que tous les nouveaux districts aient recours à des ressources en eau renouvelables à la place de l'eau souterraine. Les demandes concernant la mise en oeuvre de la loi ont conduit jusqu'à l'arrêt des activités normales des instances politiques. Resumen El Acta de Protección de los Usuarios de Agua de Tucson, Arizona (EE.UU.) de 1995 (el Acta) se aprobó a raíz de las quejas de los usuarios de agua de Tucson que recibían agua tratada por el Proyecto de Arizona Central (CAP). Las consecuencias del Acta demuestran las incertidumbres y dificultades que se producen cuando se le pide al público que vote sobre temas muy técnicos. Los requerimientos de recarga del Acta desprecian incertidumbres hidrogeológicas al confundir entre "infiltración" y "recarga". Así, el Acta dice que la infiltración en los canales de los arroyos a lo largo del Campo de Producción Central aumentará la recarga a dicho campo. De

On-Farm, Almond Orchard Flooding as a Viable Aquifer Recharge Alternative

NASA Astrophysics Data System (ADS)

Ulrich, C.; Nico, P. S.; Wu, Y.; Newman, G. A.; Conrad, M. E.; Dahlke, H. E.

2017-12-01

In 2014, California legislators passed the Sustainable Groundwater Management Act (SGMA), which requires groundwater sustainability agencies (areas) to identify/prioritize water basins, develop current and projected water use/needs, develop a groundwater management plan, develop fees, etc. One of the challenges for implementing SGMA is the lack of data that can support alternative groundwater recharge methods such as on-farm flooding. Prior to anthropogenic river control, river floodplains captured excess water during overbank flow in the rainy season in the CA central valley. Today levees and canals strategically route rainy season high flows to the delta/ocean when irrigation water is not needed. Utilizing farmland once again as infiltration basins for groundwater banking and aquifer recharge could be a viable answer to California's depleted central valley aquifers. Prior to 2017, U.C. Davis had partnered with the Almond Board of California (ABC) and local growers to study the efficacy of agricultural flooding and the effects on annual almond crops (. LBNL joined this team to help understand the conveyance of recharge water, using electrical resistivity tomography (ERT), into the subsurface (i.e. localized fast paths, depth of infiltration, etc.) during flooding events. The fate of the recharge water is what is significant to understanding the viability of on-farm flooding as an aquifer recharge option. In this study two orchards (in Delhi and Modesto, CA), each approximately 2 acres, were flooded during the almond tree dormant period (January), to recharge 2 acre/ft of water into the local aquifers. ERT was used to characterize (soil structure) and monitor water infiltration over a single flooding event to investigate the fate of applied water. Data were collected every hour prior to flooding (baseline), during, and after all flood water had infiltrated (about 5 days total). Our time-lapse ERT results show a heterogeneous soil structure that leads to non

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.

Estimating 1970-99 average annual groundwater recharge in Wisconsin using streamflow data

USGS Publications Warehouse

Gebert, Warren A.; Walker, John F.; Kennedy, James L.

2011-01-01

Average annual recharge in Wisconsin for the period 1970-99 was estimated using streamflow data from U.S. Geological Survey continuous-record streamflow-gaging stations and partial-record sites. Partial-record sites have discharge measurements collected during low-flow conditions. The average annual base flow of a stream divided by the drainage area is a good approximation of the recharge rate; therefore, once average annual base flow is determined recharge can be calculated. Estimates of recharge for nearly 72 percent of the surface area of the State are provided. The results illustrate substantial spatial variability of recharge across the State, ranging from less than 1 inch to more than 12 inches per year. The average basin size for partial-record sites (50 square miles) was less than the average basin size for the gaging stations (305 square miles). Including results for smaller basins reveals a spatial variability that otherwise would be smoothed out using only estimates for larger basins. An error analysis indicates that the techniques used provide base flow estimates with standard errors ranging from 5.4 to 14 percent.

Urban recharge beneath low impact development and effects of climate variability and change

NASA Astrophysics Data System (ADS)

Newcomer, Michelle E.; Gurdak, Jason J.; Sklar, Leonard S.; Nanus, Leora

2014-02-01

low impact development (LID) planning and best management practices (BMPs) effects on recharge is important because of the increasing use of LID BMPs to reduce storm water runoff and improve surface-water quality. LID BMPs are microscale, decentralized management techniques such as vegetated systems, pervious pavement, and infiltration trenches to capture, reduce, filter, and slow storm water runoff. Some BMPs may enhance recharge, which has often been considered a secondary management benefit. Here we report results of a field and HYDRUS-2D modeling study in San Francisco, California, USA to quantify urban recharge rates, volumes, and efficiency beneath a LID 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. 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 accurately estimating recharge under current conditions. Observed (2011-2012) and future (2099-2100) recharge rates beneath the infiltration trench (1750-3710 mm yr-1) were an order of magnitude greater than beneath the irrigated lawn (130-730 mm yr-1). Beneath the infiltration trench, recharge rates ranged from 1390 to 5840 mm yr-1 and averaged 3410 mm yr-1 for El Niño years (1954-2012) and from 1540 to 3330 mm yr-1 and averaged 2430 mm yr-1 for La Niña years. We demonstrate a clear benefit for recharge and local groundwater resources using LID BMPs.

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.

Mitigation of non-point source of fluoride on groundwater by dug well recharge

NASA Astrophysics Data System (ADS)

Ganesan, G.; Lakshmanan, E.

2017-12-01

Groundwater used for drinking purpose is affected in many regions due to the presence of excess fluoride. The excess intake of fluoride through drinking water causes fluorosis to human in many states of India, including Tamil Nadu. The present study was carried out with the objective of assessing hydrogeochemistry of groundwater and the feasibility of dug well recharge to reduce the fluoride concentration in Vaniyar river basin, Tamil Nadu, India. The major source for fluoride in groundwater of this area is the epidote hornblende gneissic and charnockite which are the major rocks occurring in this region. As a pilot study a cost effective induced recharge structure was constructed at Papichettipatty village in the study region. The study shows that the groundwater level around the recharge site raised up to 2 m from 14.5 m (bgl) and fluoride concentration has decreased from 3.8 mg/l to 0.9 mg/l due to dilution. The advantage of this induced recharge structure is of its low cost, the ease of implementation, improved groundwater recharge and dilution of fluoride in groundwater. An area of about 1.5 km2 has benefited due to this dug well recharge system.

Rechargeable calcium phosphate orthodontic cement with sustained ion release and re-release

NASA Astrophysics Data System (ADS)

Zhang, Ling; Weir, Michael D.; Chow, Laurence C.; Reynolds, Mark A.; Xu, Hockin H. K.

2016-11-01

White spot lesions (WSL) due to enamel demineralization are major complications for orthodontic treatments. Calcium phosphate (CaP) dental resins with Ca and P ion releases are promising for remineralization. However, previous Ca and P releases lasted for only weeks. Experimental orthodontic cements were developed using pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA) at mass ratio of 1:1 (PE); and PE plus 10% of 2-hydroxyethyl methacrylate (HEMA) and 5% of bisphenol A glycidyl dimethacrylate (BisGMA) (PEHB). Particles of amorphous calcium phosphate (ACP) were incorporated into PE and PEHB at 40% filler level. Specimens were tested for bracket-enamel shear bond strength, water sorption, CaP release, and ion recharge and re-release. PEHB+40ACP had higher bracket-enamel bond strength and ion release and rechargeability than PE+40ACP. ACP incorporation into the novel orthodontic cement did not adversely affect the bracket-enamel bond strength. Ion release and re-release from the novel ACP orthodontic cement indicated favorable release and re-release patterns. The recharged orthodontic cement could release CaP ions continuously for four weeks without further recharge. Novel rechargeable orthodontic cement containing ACP was developed with a high bracket-enamel bond strength and the ability to be repeatedly recharged to maintain long-term high levels of CaP ion releases.

Enhancing emerging organic compound degradation: applying chaotic flow to managed aquifer recharge

NASA Astrophysics Data System (ADS)

Rodríguez-Escales, Paula; Fernandez-Garcia, Daniel; Drechsel, Johannes; Folch, Albert; Sanchez-Vila, Xavier

2017-04-01

The coupling of Managed Aquifer Recharge with soil aquifer remediation treatment, by placing a reactive layer containing organic matter at the bottom of the infiltration pond, is a promising technology to improve the rate of degradation of EOCs. Its success is based on assuming that recharged water and groundwater get well mixed, which is not always true. It has been demonstrated that mixing can be enhanced by inducing chaotic advection through extraction-injection engineering. In this work we analyze how chaotic advection might enhance the spreading of redox conditions with the final aim of improving degradation of a mix of benzotriazoles: benzotriazole, 5-methyl-benzotriazole, and 5-chloro-benzotriazole. The first two compounds are better degraded under aerobic conditions whereas the third one under nitrate reducing conditions. We developed a reactive transport model that describes how a recharged water rich in organic matter mixes with groundwater, how this organic matter is oxidized by different electron acceptors, and how the benzotriazoles are degraded attending for the redox state. The model was tested in different scenarios of recharge, both in homogenous and in heterogenous media. It was found that chaotic flow increases the spreading of the plume of recharged water. Consequently, different redox conditions coexist at a given time within the area affected by recharge, facilitating the degradation of EOCs.

Rechargeable calcium phosphate orthodontic cement with sustained ion release and re-release

PubMed Central

Zhang, Ling; Weir, Michael D.; Chow, Laurence C.; Reynolds, Mark A.; Xu, Hockin H. K.

2016-01-01

White spot lesions (WSL) due to enamel demineralization are major complications for orthodontic treatments. Calcium phosphate (CaP) dental resins with Ca and P ion releases are promising for remineralization. However, previous Ca and P releases lasted for only weeks. Experimental orthodontic cements were developed using pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA) at mass ratio of 1:1 (PE); and PE plus 10% of 2-hydroxyethyl methacrylate (HEMA) and 5% of bisphenol A glycidyl dimethacrylate (BisGMA) (PEHB). Particles of amorphous calcium phosphate (ACP) were incorporated into PE and PEHB at 40% filler level. Specimens were tested for bracket-enamel shear bond strength, water sorption, CaP release, and ion recharge and re-release. PEHB+40ACP had higher bracket-enamel bond strength and ion release and rechargeability than PE+40ACP. ACP incorporation into the novel orthodontic cement did not adversely affect the bracket-enamel bond strength. Ion release and re-release from the novel ACP orthodontic cement indicated favorable release and re-release patterns. The recharged orthodontic cement could release CaP ions continuously for four weeks without further recharge. Novel rechargeable orthodontic cement containing ACP was developed with a high bracket-enamel bond strength and the ability to be repeatedly recharged to maintain long-term high levels of CaP ion releases. PMID:27808251

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.

Recharge Data Package for Hanford Single-Shell Tank Waste Management Areas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fayer, Michael J.; Keller, Jason M.

2007-09-24

Pacific Northwest National Laboratory (PNNL) assists CH2M HILL Hanford Group, Inc., in its preparation of the Resource Conservation and Recovery Act (RCRA) Facility Investigation report. One of the PNNL tasks is to use existing information to estimate recharge rates for past and current conditions as well as future scenarios involving cleanup and closure of tank farms. The existing information includes recharge-relevant data collected during activities associated with a host of projects, including those of RCRA, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the CH2M HILL Tank Farm Vadose Zone Project, and the PNNL Remediation and Closure Science Project.more » As new information is published, the report contents can be updated. The objective of this data package was to use published data to provide recharge estimates for the scenarios being considered in the RCRA Facility Investigation. Recharge rates were estimated for areas that remain natural and undisturbed, areas where the vegetation has been disturbed, areas where both the vegetation and the soil have been disturbed, and areas that are engineered (e.g., surface barrier). The recharge estimates supplement the estimates provided by PNNL researchers in 2006 for the Hanford Site using additional field measurements and model analysis using weather data through 2006.« less

Monitoring induced denitrification during managed aquifer recharge in an infiltration pond

NASA Astrophysics Data System (ADS)

Grau-Martínez, Alba; Folch, Albert; Torrentó, Clara; Valhondo, Cristina; Barba, Carme; Domènech, Cristina; Soler, Albert; Otero, Neus

2018-06-01

Managed aquifer recharge (MAR) is a well-known technique for improving water quality and increasing groundwater resources. Denitrification (i.e. removal of nitrate) can be enhanced during MAR by coupling an artificial recharge pond with a permeable reactive layer (PRL). In this study, we examined the suitability of a multi-isotope approach for assessing the long-term effectiveness of enhancing denitrification in a PRL containing vegetal compost. Batch laboratory experiments confirmed that the PRL was still able to enhance denitrification two years after its installation in the infiltration pond. At the field scale, changes in redox indicators along a flow path and below the MAR-PRL system were monitored over 21 months during recharge and non-recharge periods. Results showed that the PRL was still releasing non-purgeable dissolved organic carbon five years after its installation. Nitrate concentration coupled with isotopic data collected from the piezometer network at the MAR system indicated that denitrification was occurring in the saturated zone immediately beneath the infiltration pond, where recharged water and native groundwater mix. Furthermore, longer operational periods of the MAR-PRL system increased denitrification extent. Multi-isotope analyses are therefore proved to be useful tools in identifying and quantifying denitrification in MAR-PRL systems.

Ground-water recharge in the arid and semiarid southwestern United States - Climatic and geologic framework: Chapter A in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

USGS Publications Warehouse

Stonestrom, David A.; Harrill, James R.; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

2007-01-01

Ground-water recharge in the arid and semiarid southwestern United States results from the complex interplay of climate, geology, and vegetation across widely ranging spatial and temporal scales. Present-day recharge tends to be narrowly focused in time and space. Widespread water-table declines accompanied agricultural development during the twentieth century, demonstrating that sustainable ground-water supplies are not guaranteed when part of the extracted resource represents paleorecharge. Climatic controls on ground-water recharge range from seasonal cycles of summer monsoonal and winter frontal storms to multimillennial cycles of glacial and interglacial periods. Precipitation patterns reflect global-scale interactions among the oceans, atmosphere, and continents. Large-scale climatic influences associated with El Niño and Pacific Decadal Oscillations strongly but irregularly control weather in the study area, so that year-to-year variations in precipitation and ground-water recharge are large and difficult to predict. Proxy data indicate geologically recent periods of multidecadal droughts unlike any in the modern instrumental record. Anthropogenically induced climate change likely will reduce ground-water recharge through diminished snowpack at higher elevations, and perhaps through increased drought. Future changes in El Niño and monsoonal patterns, both crucial to precipitation in the study area, are highly uncertain in current models. Land-use modifications influence ground-water recharge directly through vegetation, irrigation, and impermeable area, and indirectly through climate change. High ranges bounding the study area—the San Bernadino Mountains and Sierra Nevada to the west, and the Wasatch and southern Colorado Rocky Mountains to the east—provide external geologic controls on ground-water recharge. Internal geologic controls stem from tectonic processes that led to numerous, variably connected alluvial-filled basins, exposure of extensive

Mountain-front recharge along the eastern side of the Middle Rio Grande Basin, central New Mexico

USGS Publications Warehouse

Anderholm, Scott K.

2000-01-01

Mountain-front recharge, which generally occurs along the margins of alluvial basins, can be a large part of total recharge to the aquifer system in such basins. Mountain-front recharge occurs as the result of infiltration of flow from streams that have headwaters in the mountainous areas adjacent to alluvial basins and ground- water flow from the aquifers in the mountainous areas to the aquifer in the alluvial basin. This report presents estimates of mountain-front recharge to the basin-fill aquifer along the eastern side of the Middle Rio Grande Basin in central New Mexico. The basin is a structural feature that contains a large thickness of basin-fill deposits, which compose the main aquifer in the basin. The basin is bounded along the eastern side by mountains composed of crystalline rocks of Precambrian age and sedimentary rocks of Paleozoic age. Precipitation is much larger in the mountains than in the basin; many stream channels debouch from the mountainous area to the basin. Chloride-balance and water-yield regression methods were used to estimate mountain-front recharge. The chloride-balance method was used to calculate a chloride balance in watersheds in the mountainous areas along the eastern side of the basin (subareas). The source of chloride to these watersheds is bulk precipitation (wet and dry deposition). Chloride leaves these watersheds as mountain-front recharge. The water-yield regression method was used to determine the streamflow from the mountainous watersheds at the mountain front. This streamflow was assumed to be equal to mountain-front recharge because most of this streamflow infiltrates and recharges the basin-fill aquifer. Total mountain-front recharge along the eastern side of the Middle Rio Grande Basin was estimated to be about 11,000 acre- feet per year using the chloride-balance method and about 36,000 and 38,000 acre-feet per year using two water-yield regression equations. There was a large range in the recharge estimates in a

Recharge of valley-fill aquifers in the glaciated northeast from upland runoff

USGS Publications Warehouse

Williams, J.H.; Morrissey, D.J.

1996-01-01

Channeled and unchanneled runoff from till-covered bedrock uplands is a major source of recharge to valley-fill aquifers in the glaciated northeastern United States. Streamflow measurements and model simulation of average steady-state conditions indicate that upland runoff accounted for more recharge to two valley-fill aquifers in moderately high topographic-relief settings than did direct infiltration of precipitation. Recharge from upland runoff to a modeled valley-fill aquifer in an area of lower relief was significant but less than that from direct infiltration of precipitation. The amount of upland runoff available for recharging valley-fill aquifers in the glaciated Northeast ranges from about 1.5 to 2.5 cubic feet per second per square mile of drainage area that borders the aquifer. Stream losses from tributaries that drain the uplands commonly range from 0.3 to 1.5 cubic feet per second per 1,000 feet of wetted channel where the tributaries cross alluvial fans in the main valleys. Recharge of valley-fill aquifers from channeled runoff was estimated from measured losses and average runoff rates and was represented in aquifer models as specified fluxes or simulated by head-dependent fluxes with streamflow routing in the model cells that represent the tributary streams. Unchanneled upland runoff, which includes overland and subsurface flow, recharges the valley-fill aquifers at the contact between the aquifer and uplands near the base of the bordering till-covered hillslopes. Recharge from unchanneled runoff was estimated from average runoff rates and the hillslope area that borders the aquifer and was represented as specified fluxes to model-boundary cells along the valley walls.

Potential groundwater recharge for the State of Minnesota using the Soil-Water-Balance model, 1996-2010

USGS Publications Warehouse

Smith, Erik A.; Westenbroek, Stephen M.

2015-01-01

On an annual basis, however, potential recharge rates were as high as 27.2 inches per year. The highest annual mean recharge estimate across the State was for 2010, and the lowest mean recharge estimate was for 2003. Although precipitation variability partially explained the annual differences in potential recharge estimates, precipitation alone did not account for these differences, and other factors such as antecedent moisture conditions likely were important. Also, because precipitation gradients across the State can vary from year to year, the dominant land-cover class and hydrologic soil group combinations for a particular region had a large effect on the resulting potential recharge value. During 1996–2010, April had the greatest monthly mean potential recharge compared to all other months, accounting for a mean of 30 percent of annual potential recharge in this single month.

Assessment of check-dam groundwater recharge with water-balance calculations

NASA Astrophysics Data System (ADS)

Djuma, Hakan; Bruggeman, Adriana; Camera, Corrado; Eliades, Marinos

2017-04-01

Studies on the enhancement of groundwater recharge by check-dams in arid and semi-arid environments mainly focus on deriving water infiltration rates from the check-dam ponding areas. This is usually achieved by applying simple water balance models, more advanced models (e.g., two dimensional groundwater models) and field tests (e.g., infiltrometer test or soil pit tests). Recharge behind the check-dam can be affected by the built-up of sediment as a result of erosion in the upstream watershed area. This natural process can increase the uncertainty in the estimates of the recharged water volume, especially for water balance calculations. Few water balance field studies of individual check-dams have been presented in the literature and none of them presented associated uncertainties of their estimates. The objectives of this study are i) to assess the effect of a check-dam on groundwater recharge from an ephemeral river; and ii) to assess annual sedimentation at the check-dam during a 4-year period. The study was conducted on a check-dam in the semi-arid island of Cyprus. Field campaigns were carried out to measure water flow, water depth and check-dam topography in order to establish check-dam water height, volume, evaporation, outflow and recharge relations. Topographic surveys were repeated at the end of consecutive hydrological years to estimate the sediment built up in the reservoir area of the check dam. Also, sediment samples were collected from the check-dam reservoir area for bulk-density analyses. To quantify the groundwater recharge, a water balance model was applied at two locations: at the check-dam and corresponding reservoir area, and at a 4-km stretch of the river bed without check-dam. Results showed that a check-dam with a storage capacity of 25,000 m3 was able to recharge to the aquifer, in four years, a total of 12 million m3 out of the 42 million m3 of measured (or modelled) streamflow. Recharge from the analyzed 4-km long river section without

Unsteady seepage flow over sloping beds in response to multiple localized recharge

NASA Astrophysics Data System (ADS)

Bansal, Rajeev K.

2017-05-01

New generalized solutions of linearized Boussinesq equation are derived to approximate the dynamic behavior of subsurface seepage flow induced by multiple localized time-varying recharges over sloping ditch-drain aquifer system. The mathematical model is based on extended Dupuit-Forchheimer assumption and treats the spatial location of recharge basins as additional parameter. Closed form analytic expressions for spatio-temporal variations in water head distribution and discharge rate into the drains are obtained by solving the governing flow equation using eigenvalue-eigenfunction method. Downward and zero-sloping aquifers are treated as special cases of main results. A numerical example is used for illustration of combined effects of various parameters such as spatial coordinates of the recharge basin, aquifer's bed slope, and recharge rate on the dynamic profiles of phreatic surface.

Rainfall recharge estimation on a nation-wide scale using satellite information in New Zealand

NASA Astrophysics Data System (ADS)

Westerhoff, Rogier; White, Paul; Moore, Catherine

2015-04-01

Models of rainfall recharge to groundwater are challenged by the need to combine uncertain estimates of rainfall, evapotranspiration, terrain slope, and unsaturated zone parameters (e.g., soil drainage and hydraulic conductivity of the subsurface). Therefore, rainfall recharge is easiest to estimate on a local scale in well-drained plains, where it is known that rainfall directly recharges groundwater. In New Zealand, this simplified approach works in the policy framework of regional councils, who manage water allocation at the aquifer and sub-catchment scales. However, a consistent overview of rainfall recharge is difficult to obtain at catchment and national scale: in addition to data uncertainties, data formats are inconsistent between catchments; the density of ground observations, where these exist, differs across regions; each region typically uses different local models for estimating recharge components; and different methods and ground observations are used for calibration and validation of these models. The research described in this paper therefore presents a nation-wide approach to estimate rainfall recharge in New Zealand. The method used is a soil water balance approach, with input data from national rainfall and soil and geology databases. Satellite data (i.e., evapotranspiration, soil moisture, and terrain) aid in the improved calculation of rainfall recharge, especially in data-sparse areas. A first version of the model has been implemented on a 1 km x 1 km and monthly scale between 2000 and 2013. A further version will include a quantification of recharge estimate uncertainty: with both "top down" input error propagation methods and catchment-wide "bottom up" assessments of integrated uncertainty being adopted. Using one nation-wide methodology opens up new possibilities: it can, for example, help in more consistent estimation of water budgets, groundwater fluxes, or other hydrological parameters. Since recharge is estimated for the entire land

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).

Promoting the Market for Plug-in Hybrid and Battery Electric Vehicles: Role of Recharge Availability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Zhenhong; Greene, David L

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 benefitsmore » 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.« less

Behavior of TOC in a Deep Confined Aquifer During Groundwater Artificial Recharge Process

NASA Astrophysics Data System (ADS)

Zhang, W.; He, H.; Shi, X.

2013-12-01

In recent years, environmental geological problems such as land subsidence, land collapse, land cracking and salt-water intrusion have become important factors limiting economic development in some cities due to severe overexploitation of groundwater. So, a number of cities have carried out artificial recharge projects, which have played a significant role in controlling these problems. However, with the increasing trend of organic pollution appeared in the surface water, organic contaminated problems should not be neglected during this process. Although the organic components were always following in a lower concentration level, whether it would make groundwater face the organic pollution crisis was unknown for its' higher toxicity and durability. Based on a typical artificial recharge test carried out in a deep confined aquifer in this study area (located in Eastern China, there are 10 monitoring wells and 1 recharge well) that decided to control the field land subsidence, Total Organic Carbon (TOC) was selected as the target components to reveal the organic elements' changing trend during groundwater artificial recharge process. The results (Fig. 1) showed that the concentration of TOC in each monitoring well was appeared in an increasing trend due to the mix influence of the recharge water (TOC was 1.88mg/L) and the origin groundwater (TOC was 0.58mg/L). But the maximum concentrations of TOC in J4, J5, J6 monitoring well (the distance from recharge well was 10m, 17m, 31m respectively) were lower than the recharge water 0.28, 0.49, 0.74 mg/L respectively, with non-linear growth. It indicated that except adsorption, microbial degradation might also occur in the aquifer during artificial recharge. With the groundwater environment from relatively anaerobic environment turn to aerobic environment, DO was able to characterize the relative strength of the TOC biodegradation. The average value of DO in recharge water was 4.33 mg/L, and the maximum value of DO in J4, J5

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.

Interactions of diffuse and focused allogenic recharge in an eogenetic karst aquifer (Florida, USA)

NASA Astrophysics Data System (ADS)

Langston, Abigail L.; Screaton, Elizabeth J.; Martin, Jonathan B.; Bailly-Comte, Vincent

2012-06-01

The karstic upper Floridan aquifer in north-central Florida (USA) is recharged by both diffuse and allogenic recharge. To understand how recharged water moves within the aquifer, water levels and specific conductivities were monitored and slug tests were conducted in wells installed in the aquifer surrounding the Santa Fe River Sink and Rise. Results indicate that diffuse recharge does not mix rapidly within the aquifer but instead flows horizontally. Stratification may be aided by the high matrix porosity of the eogenetic karst aquifer. Purging wells for sample collection perturbed conductivity for several days, reflecting mixing of the stratified water and rendering collection of representative samples difficult. Interpretive numerical simulations suggest that diffuse recharge impacts the intrusion of allogenic water from the conduit by increasing hydraulic head in the surrounding aquifer and thereby reducing influx to the aquifer from the conduit. In turn, the increase of head within the conduits affects flow paths of diffuse recharge by moving newly recharged water vertically as the water table rises and falls. This movement may result in a broad vertical zone of dissolution at the water table above the conduit system, with thinner and more focused water-table dissolution at greater distance from the conduit.

A water-budget model and assessment of groundwater recharge for the Island of Hawaiʻi

USGS Publications Warehouse

Engott, John A.

2011-01-01

Concern surrounding increasing demand for groundwater on the Island of Hawaiʻi, caused by a growing population and an increasing reliance on groundwater as a source for municipal and private water systems, has prompted a study of groundwater recharge on the island using the most current data and accepted methods. For this study, a daily water-budget model for the entire Island of Hawaiʻi was developed and used to estimate mean recharge for various land-cover and rainfall conditions, and a submodel for the Kona area was developed and used to estimate historical groundwater recharge in the Kona area during the period 1984–2008. Estimated mean annual recharge on the Island of Hawaiʻi is 6,594 million gallons per day, which is about 49 percent of mean annual rainfall. Recharge is highest on the windward slopes of Mauna Loa, below the tradewind inversion, and lowest on the leeward slopes of Kohala and Mauna Kea. Local recharge maxima also occur on (1) windward Kohala, with the exception of the northern tip, (2) windward Mauna Kea below the tradewind inversion, (3) windward Kīlauea, (4) the middle elevations of southeastern Mauna Loa, and (5) the lower-middle elevations of leeward Mauna Loa and southwestern Hualālai, in the Kona area. Local recharge minima also occur on (1) Mauna Kea and Mauna Loa, above the tradewind inversion, (2) the northern tip of Kohala, (3) leeward Kīlauea, (4) the southern tip of Mauna Loa, and (5) the northwestern slopes of Mauna Loa and Hualālai. In 18 of the 24 aquifer systems on the island, estimated mean annual recharge for baseline conditions was higher than the recharge estimates used in the 2008 State of Hawaiʻi Water Resource Protection Plan (2008 WRPP). Baseline conditions for this study were 2008 land cover and mean annual rainfall from the period 1916–1983. Estimates of recharge for the Māhukona, Waimea, and Hāwī aquifer systems, however, were between 29 and 38 percent lower than the 2008 WRPP estimates, mainly because

Annotated bibliography on artificial recharge of ground water, 1955-67

USGS Publications Warehouse

Signor, Donald C.; Growitz, Douglas J.; Kam, William

1970-01-01

Artificial ground-water recharge has become more important as water use by agriculture, industry, and municipalities increases. Water management agencies are increasingly interested in potential use of recharge for pollution abatement, waste-water disposal, and re-use and reclamation of locally available supplies. Research projects and theoretical analyses of operational recharge systems show increased scientific emphasis on the practice. Overall ground-water basin management systems generally now contain considerations of artificial recharge, whether by direct or indirect methods. Artificial ground-water recharge is a means of conserving surface runoff for future use in places where it would otherwise be lost, of protecting ground-water basins from salt-water encroachment along coastal areas, and of storing and distributing imported water. The biblio-graphy emphasizes technology; however, annotations of articles on waste-water reclamation, ground-water management and ground-water basin management are included. Subjects closely related to artificial recharge, including colloidal flow through porous media, field or laboratory instrumentation, and waste disposal by deep well injection are included where they specifically relate to potential recharge problems. Where almost the same material has been published in several journals, all references are included on the assumption that some publications may be more readily available to interested persons than others. Other publications, especially those of foreign literature, provided abstracts that were used freely as time limitations precluded obtaining and annotating all materials. Abstracts taken from published sources are noted. These are: "Abstracts of North American Geology," U.S. Department of the Interior, Geological Survey; "Abstracts of Recent Published Material on Foil and Water Conservation," ARS-41 series, Agricultural F.esearch Service, U.S. Department of Agriculture; "Water and1 Water

Coupled Model Development between Groundwater Recharge Quantity and Climate Change in Nakdong River Watershed using GIS

NASA Astrophysics Data System (ADS)

Lee, M.; Jeongho, L.; Changsub, S.; SeongWoo, J.

2011-12-01

: Global climate change is disturbing the water circulation balance by changing rates of precipitation, recharge and discharge, and evapotranspiration. Groundwater, which occupies a considerable portion of the world's water resources, is related to climate change via surface water such as rivers, lakes, and marshes. In this study, the authors selected a relevant climate change scenario, A1B from the Special Report on Emission Scenario (SRES) which is distributed at Korea Meteorological Administration. By using data on temperature, rainfall, soil, and land use, the groundwater recharge rate for the research area was estimated by periodically and embodied as geographic information system (GIS). In order to calculate the groundwater recharge quantity, Visual HELP3 was used as main model, and the physical properties of weather, temperature, and soil layers were used as main input data. General changes to water circulation due to climate change have already been predicted. In order to systematically solve problems of ground circulation system, it may be urgent to recalculate the groundwater recharge quantity and consequent change under future climate change. The space-time calculation of changes of the groundwater recharge quantity in the study area may serve as a foundation to present additional measures to improve domestic groundwater resource management. Results showed that 26.19% of total precipitation was recharged from 1971 to 2000, 27.37% will be recharged from 2001 to 2030, 27.43% will be recharged from 2031 to 2050, and 26.06% will be recharged from 2051 to 2070, 27.88% will be recharged from 2051 to 2100. The groundwater recharge rate in this research showed susceptibility to changes in precipitation. The recharge rate was relatively little affected by the changes in Curve Number (CN), but it was rapidly reduced, as it approached the impermeable layers. Accordingly, the findings herein provide a basis for establishment of national plans on water resources

Development of an Ultra-Safe Rechargeable Lithium-Ion Battery.

DTIC Science & Technology

1994-11-15

34 DEVELOPMENT OF AN ULTRA-SAFE RECHARGEABLE LITHIUM - ION BATTERY DTIC \\ JANI 0 1995 19941221 079 Contract # N00014-94-C-0141 ARPA Order...DEVELOPMENT OF AN ULTRA-SAFE RECHARGEABLE LITHIUM - ION BATTERY R&D STATUS REPORT 1931-1001/0 ARPA Order No.: 9332004arp01/13APR1994/313ES Program Code...Title of Work: Lithium - ion Battery Development Reporting Period: August 15, 1994 to November 15, 1994 Description of Progress: The project activities had

Iron-Air Rechargeable Battery

NASA Technical Reports Server (NTRS)

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

77 FR 39321 - Eighth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-02

... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Sizes AGENCY: Federal... Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Sizes. SUMMARY... 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Sizes. DATES: The meeting will...

78 FR 6845 - Eleventh Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-31

... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal... Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. DATES: The meeting...

78 FR 16031 - Twelfth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-13

... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal... Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. DATES: The meeting...

78 FR 55773 - Fourteenth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-11

... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal... Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size DATES: The meeting...

78 FR 38093 - Thirteenth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-25

... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal... Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. DATES: The meeting...

Borehole environmental tracers for evaluating net infiltration and recharge through desert bedrock

USGS Publications Warehouse

Heilweil, V.M.; Solomon, D.K.; Gardner, P.M.

2006-01-01

Permeable bedrock aquifers in arid regions are being increasingly developed as water supplies, yet little is generally known about recharge processes and spatial and temporal variability. Environmental tracers from boreholes were used in this study to investigate net infiltration and recharge to the fractured Navajo Sandstone aquifer. Vadose zone tracer profiles at the Sand Hollow study site in southwestern Utah look similar to those of desert soils at other sites, indicating the predominance of matrix flow. However, recharge rates are generally higher in the Navajo Sandstone than in unconsolidated soils in similar climates because the sandstone matrix allows water movement but not root penetration. Water enters the vadose zone either as direct infiltration of precipitation through exposed sandstone and sandy soils or as focused infiltration of runoff. Net infiltration and recharge exhibit extreme spatial variability. High-recharge borehole sites generally have large amounts of vadose zone tritium, low chloride concentrations, and small vadose zone oxygen-18 evaporative shifts. Annual net-infiltration and recharge rates at different locations range from about 1 to 60 mm as determined using vadose zone tritium, 0 to 15 mm using vadose zone chloride, and 3 to 60 mm using groundwater chloride. Environmental tracers indicate a cyclical net-infiltration and recharge pattern, with higher rates earlier in the Holocene and lower rates during the late Holocene, and a return to higher rates during recent decades associated with anomalously high precipitation during the latter part of the 20th century. The slightly enriched stable isotopic composition of modern groundwater indicates this recent increase in precipitation may be caused by a stronger summer monsoon or winter southern Pacific El Nin??o storm track. ?? Soil Science Society of America.

Thin Rechargeable Batteries for CMOS SRAM Memory Protection

NASA Technical Reports Server (NTRS)

Crouse, Dennis N.

1993-01-01

New rechargeable battery technology is described and compared with classical primary battery back-up of SRAM PC cards. Thin solid polymer electrolyte cells with the thickness of TSOP memory components (1 mm nominal, 1.1 mm max) and capacities of 14 mAh/sq cm can replace coin cells. The SRAM PC cards with permanently installed rechargeable cells and optional electrochromic low battery voltage indicators will free the periodic PC card user from having to 'feed' their PC cards with coin cells and will allow a quick visual check of stored cards for their battery voltage status.

A groundwater recharge perspective on locating tree plantations within low-rainfall catchments to limit water resource losses

NASA Astrophysics Data System (ADS)

Dean, J. F.; Webb, J. A.; Jacobsen, G. E.; Chisari, R.; Dresel, P. E.

2015-02-01

Despite the many studies that consider the impacts of plantation forestry on groundwater recharge, and others that explore the spatial heterogeneity of recharge in low-rainfall regions, there is little marriage of the two subjects in forestry management guidelines and legislation. Here we carry out an in-depth analysis of the impact of reforestation on groundwater recharge in a low-rainfall (< 700 mm annually), high-evapotranspiration paired catchment characterized by ephemeral streams. Water table fluctuation (WTF) estimates of modern recharge indicate that little groundwater recharge occurs along the topographic highs of the catchments (average 18 mm yr-1); instead the steeper slopes in these areas direct runoff downslope to the lowland areas, where most recharge occurs (average 78 mm yr-1). Recharge estimates using the chloride mass balance (CMB) method were corrected by replacing the rainfall input Cl- value with that for streamflow, because most recharge occurs from infiltration of runoff through the streambed and adjacent low gradient slopes. The calculated CMB recharge values (average 10 mm yr-1) are lower than the WTF recharge values (average 47 mm yr-1), because they are representative of groundwater that was mostly recharged prior to European land clearance (> BP 200 years). The tree plantation has caused a progressive drawdown in groundwater levels due to tree water use; the decline is less in the upland areas. The results of this study show that spatial variations in recharge are important considerations for locating tree plantations. To conserve water resources for downstream users in low-rainfall, high-evapotranspiration regions, tree planting should be avoided in the dominant zone of recharge, i.e. the topographically low areas and along the drainage lines, and should be concentrated on the upper slopes, although this may negatively impact the economic viability of the plantation.

Groundwater recharge in irrigated semi-arid areas: quantitative hydrological modelling and sensitivity analysis

NASA Astrophysics Data System (ADS)

Jiménez-Martínez, Joaquín; Candela, Lucila; Molinero, Jorge; Tamoh, Karim

2010-12-01

For semi-arid regions, methods of assessing aquifer recharge usually consider the potential evapotranspiration. Actual evapotranspiration rates can be below potential rates for long periods of time, even in irrigated systems. Accurate estimations of aquifer recharge in semi-arid areas under irrigated agriculture are essential for sustainable water-resources management. A method to estimate aquifer recharge from irrigated farmland has been tested. The water-balance-modelling approach was based on VisualBALAN v. 2.0, a computer code that simulates water balance in the soil, vadose zone and aquifer. The study was carried out in the Campo de Cartagena (SE Spain) in the period 1999-2008 for three different groups of crops: annual row crops (lettuce and melon), perennial vegetables (artichoke) and fruit trees (citrus). Computed mean-annual-recharge values (from irrigation+precipitation) during the study period were 397 mm for annual row crops, 201 mm for perennial vegetables and 194 mm for fruit trees: 31.4, 20.7 and 20.5% of the total applied water, respectively. The effects of rainfall events on the final recharge were clearly observed, due to the continuously high water content in soil which facilitated the infiltration process. A sensitivity analysis to assess the reliability and uncertainty of recharge estimations was carried out.

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.

GROUNDWATER RECHARGE AND CHEMICAL ...

EPA Pesticide Factsheets

The existing knowledge base regarding the presence and significance of chemicals foreign to the subsurface environment is large and growing -the papers in this volume serving as recent testament. But complex questions with few answers surround the unknowns regarding the potential for environmental or human health effects from trace levels of xenobiotics in groundwater, especially groundwater augmented with treated wastewater. Public acceptance for direct or indirect groundwater recharge using treated municipal wastewater ( especially sewage) spans the spectrum from unquestioned embrace to outright rejection. In this article, I detour around the issues most commonly discussed for groundwater recharge and instead focus on some of the less-recognized issues- those that emanate from the mysteries created at the many literal and virtual interfaces involved with the subsurface world. My major objective is to catalyze discussion that advances our understanding of the barriers to public acceptance of wastewater reuse -with its ultimate culmination in direct reuse for drinking. I pose what could be a key question as to whether much of the public's frustration or ambivalence in its decision making process for accepting or rejecting water reuse (for various purposes including personal use) emanates from fundamental inaccuracies, misrepresentation, or oversimplification of what water 'is' and how it functions in the environment -just what exactly is the 'water cyc

Modelling of groundwater recharge and drought statistics within the framework of a climate impact study in a Mediterranean catchment (Thau Lagoon, France)

NASA Astrophysics Data System (ADS)

Herrmann, Frank; Baghdadi, Nicolas; Deidda, Roberto; La Jeunesse, Isabelle; Ludwig, Ralf; Sellami, Haykel; Vereecken, Harry; Wendland, Frank

2014-05-01

recharge up to 25 mm/a until 2070 compared to the reference period 1971-2000, whereas one RCM-mGROWA combination projects a nearly constant level of groundwater recharge for the future. The calculated drought indices however indicate that the frequency and duration of droughts will increase until 2070. References: Deidda R., M. Marrocu, G. Caroletti, G. Pusceddu, A. Langousis, V. Lucarini, M. Puliga, and A. Speranza (2013), Regional climate models' performance in representing precipitation and temperature over selected Mediterranean areas, Hydrology and Earth System Sciences, 17, 5041-5059, doi:10.5194/hess-17-5041-2013 Herrmann, F., Chen, S., Heidt, L., Elbracht, J., Engel, N., Kunkel, R., Müller, U., Röhm, H., Vereecken, H., Wendland, F., 2013. Zeitlich und räumlich hochaufgelöste flächendifferenzierte Simulation des Landschaftswasserhaushalts in Niedersachsen mit dem Model mGROWA. Hydrologie und Wasserbewirtschaftung, 57(5): 206-224.

77 FR 8325 - Sixth Meeting: RTCA Special Committee 225, Rechargeable Lithium Batteries and Battery Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-14

... 225, Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size AGENCY: Federal... Committee 225, Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size. SUMMARY: The FAA..., Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size. DATES: The meeting will be held...

Simulated response of the Sparta Aquifer to outcrop area recharge augmentation, southeastern Arkansas

USGS Publications Warehouse

Hays, Phillip D.

2001-01-01

Recharge augmentation by construction of infiltration impoundments is a potential means of increasing aquifer water levels and aquifer yield that is under consideration for the Sparta aquifer in southeastern Arkansas. The aquifer is a major water resource for municipal, industrial, and agricultural uses, and approximately 287 million gallons per day was pumped from the aquifer in Arkansas in 1995; this is double the amount pumped in 1975. Historically, the Sparta aquifer has provided abundant water of high quality. In recent years, however, the demand for water in some areas has resulted in withdrawals from the Sparta that significantly exceed recharge to the aquifer, and considerable declines have occurred in the potentiometric surface. To better manage the Sparta aquifer, water users in Arkansas are evaluating and implementing a variety of management practices and assessing alternative, surface-water sources to reduce stress upon the Sparta aquifer. One approach to managing and maximizing use of the Sparta aquifer is augmenting recharge to the aquifer by construction of infiltration lakes or canals within the recharge area. The basic concept of augmented recharge is simply to increase the amount of water being introduced into the aquifer so that more water will be available for use. Ground-water flow model simulations were conducted to assess the effectiveness of constructing lakes or canals to augment recharge. Results show that construction of five new lakes in the Sparta recharge area upgradient from major pumping centers or construction of a series of canals along the length of the recharge area yield notable benefit to aquifer conditions when compared with simulations entailing no augmentation of recharge. Augmentation of recharge in the Sparta aquifer with emplacement of lakes provides slight increase to aquifer water levels. The presence of the lakes increased simulated aquifer water levels 0.5 foot or more across a broad area comprising all or a

A review of radioactive isotopes and other residence time tracers in understanding groundwater recharge: Possibilities, challenges, and limitations

NASA Astrophysics Data System (ADS)

Cartwright, Ian; Cendón, Dioni; Currell, Matthew; Meredith, Karina

2017-12-01

Documenting the location and magnitude of groundwater recharge is critical for understanding groundwater flow systems. Radioactive tracers, notably 14C, 3H, 36Cl, and the noble gases, together with other tracers whose concentrations vary over time, such as the chlorofluorocarbons or sulfur hexafluoride, are commonly used to estimate recharge rates. This review discusses some of the advantages and problems of using these tracers to estimate recharge rates. The suite of tracers allows recharge to be estimated over timescales ranging from a few years to several hundred thousand years, which allows both the long-term and modern behaviour of groundwater systems to be documented. All tracers record mean residence times and mean recharge rates rather than a specific age and date of recharge. The timescale over which recharge rates are averaged increases with the mean residence time. This is an advantage in providing representative recharge rates but presents a problem in comparing recharge rates derived from these tracers with those from other techniques, such as water table fluctuations or lysimeters. In addition to issues relating to the sampling and interpretation of specific tracers, macroscopic dispersion and mixing in groundwater flow systems limit how precisely groundwater residence times and recharge rates may be estimated. Additionally, many recharge studies have utilised existing infrastructure that may not be ideal for this purpose (e.g., wells with long screens that sample groundwater several kilometres from the recharge area). Ideal recharge studies would collect sufficient information to optimise the use of specific tracers and minimise the problems of mixing and dispersion.

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.

77 FR 20688 - Seventh Meeting: RTCA Special Committee 225, Rechargeable Lithium Batteries and Battery Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-05

... Committee 225, Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size AGENCY: Federal... Committee 225, Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size. SUMMARY: The FAA..., Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size. DATES: The meeting will be held May...

Lithium rechargeable cell with a polymer cathode

NASA Astrophysics Data System (ADS)

Walker, Charles W., Jr.

1991-11-01

Thin films of electropolymerized poly 3-methylthiophene (PMT) were used as a rechargeable cathode in Li(SO2)3AlCl4 electrolyte. Capacity was superior to porous carbon electrodes of like thickness. Pulse power levels of 2 W cm-2 were achieved, and high rate constant current pulses of four-second duration were reproducible over cycles. Cells could be recharged at potentials below 4.0 V, minimizing the formation of chlorine and thereby diminishing the capacity for corrosion. For a primary cell, greater discharge capacity was obtained with thionyl chloride and sulfuryl chloride electrolytes. Since PMT becomes electrically insulating in the reduced state, this could be used as a built-in safety feature to avert the hazards associated with abuse over-discharge.

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.

Rechargeable Infection-responsive Antifungal Denture Materials

PubMed Central

Cao, Z.; Sun, X.; Yeh, C.-K.; Sun, Y.

2010-01-01

Candida-associated denture stomatitis (CADS) is a significant clinical concern. We developed rechargeable infection-responsive antifungal denture materials for potentially managing the disease. Polymethacrylic acid (PMAA) was covalently bound onto diurethane dimethacrylate denture resins in the curing step. The PMAA resins bound cationic antifungal drugs such as miconazole and chlorhexidine digluconate (CG) through ionic interactions. The anticandidal activities of the drug-containing PMAA-resin discs were sustained for a prolonged period of time (weeks and months). Drug release was much faster at acidic conditions (pH 5) than at pH 7. Drugs bound to the denture materials could be “washed out” by treatment with EDTA, and the drug-depleted resins could be recharged with the same or a different class of anticandidal drugs. These results suggest clinical potential of the newly developed antifungal denture materials in the management of CADS and other infectious conditions. PMID:20940361

Rechargeable infection-responsive antifungal denture materials.

PubMed

Cao, Z; Sun, X; Yeh, C-K; Sun, Y

2010-12-01

Candida-associated denture stomatitis (CADS) is a significant clinical concern. We developed rechargeable infection-responsive antifungal denture materials for potentially managing the disease. Polymethacrylic acid (PMAA) was covalently bound onto diurethane dimethacrylate denture resins in the curing step. The PMAA resins bound cationic antifungal drugs such as miconazole and chlorhexidine digluconate (CG) through ionic interactions. The anticandidal activities of the drug-containing PMAA-resin discs were sustained for a prolonged period of time (weeks and months). Drug release was much faster at acidic conditions (pH 5) than at pH 7. Drugs bound to the denture materials could be "washed out" by treatment with EDTA, and the drug-depleted resins could be recharged with the same or a different class of anticandidal drugs. These results suggest clinical potential of the newly developed antifungal denture materials in the management of CADS and other infectious conditions.

Feasibility and potential effects of the proposed Amargosa Creek Recharge Project, Palmdale, California

USGS Publications Warehouse

Christensen, Allen H.; Siade, Adam J.; Martin, Peter; Langenheim, V.E.; Catchings, Rufus D.; Burgess, Matthew K.

2015-09-17

The hydraulic conductivities of faults were estimated on the basis of water-level data and an estimate of natural recharge along Amargosa Creek. With assumed horizontal hydraulic conductivities of 10 and 100 feet per day in the upper 150 feet, the simulated maximum artificial recharge rates to the regional flow system at the ACRP were 3,400 and 9,400 acre-feet per year, respectively. These maximum recharge rates were limited primarily by the horizontal hydraulic conductivity in the upper 150 feet and by the liquefaction constraint. Future monitoring of water-level and soil-water content changes during the proposed project would allow improved estimation of aquifer hydraulic properties, the effect of the faults on groundwater movement, and the overall recharge capacity of the ACRP.

Aquifer Recharge Estimation In Unsaturated Porous Rock Using Darcian And Geophysical Methods.

NASA Astrophysics Data System (ADS)

Nimmo, J. R.; De Carlo, L.; Masciale, R.; Turturro, A. C.; Perkins, K. S.; Caputo, M. C.

2016-12-01

Within the unsaturated zone a constant downward gravity-driven flux of water commonly exists at depths ranging from a few meters to tens of meters depending on climate, medium, and vegetation. In this case a steady-state application of Darcy's law can provide recharge rate estimates.We have applied an integrated approach that combines field geophysical measurements with laboratory hydraulic property measurements on core samples to produce accurate estimates of steady-state aquifer recharge, or, in cases where episodic recharge also occurs, the steady component of recharge. The method requires (1) measurement of the water content existing in the deep unsaturated zone at the location of a core sample retrieved for lab measurements, and (2) measurement of the core sample's unsaturated hydraulic conductivity over a range of water content that includes the value measured in situ. Both types of measurements must be done with high accuracy. Darcy's law applied with the measured unsaturated hydraulic conductivity and gravitational driving force provides recharge estimates.Aquifer recharge was estimated using Darcian and geophysical methods at a deep porous rock (calcarenite) experimental site in Canosa, southern Italy. Electrical Resistivity Tomography (ERT) and Vertical Electrical Sounding (VES) profiles were collected from the land surface to water table to provide data for Darcian recharge estimation. Volumetric water content was estimated from resistivity profiles using a laboratory-derived calibration function based on Archie's law for rock samples from the experimental site, where electrical conductivity of the rock was related to the porosity and water saturation. Multiple-depth core samples were evaluated using the Quasi-Steady Centrifuge (QSC) method to obtain hydraulic conductivity (K), matric potential (ψ), and water content (θ) estimates within this profile. Laboratory-determined unsaturated hydraulic conductivity ranged from 3.90 x 10-9 to 1.02 x 10-5 m

Recharge studies on the High Plains in northern Lea County, New Mexico

USGS Publications Warehouse

Havens, John S.

1966-01-01

The area described in this report is that part of the southern High Plains principally within northern Lea County, N. Mex. ; it comprises about 1,400,000 acres. Hydrologic boundaries isolate the main aquifer of the area, the Ogallala Formation, from outside sources of natural recharge other than precipitation on the area. Natural recharge to this aquifer from the 15-inch average annual precipitation for the period 1949-60 is estimated to be about 95,000 acre-ft (acre-feet) which is between the 59,000 and 118,000 acre-ft a year obtained from the This estimate (1934) of ? to 1 inch a year. About one-sixth of the water pumped for irrigation, or an average of about 23,000 acre-ft a year in the period 1949-60, returns to the aquifer. The estimated long-term (1939-60) average annual recharge to the aquifer is about 77,000 acre-ft. Discharge from the aquifer is by pumping and underflow from the area. Gross pumpage averaged about 151,000 acre-ft a year in the period 1949-60. Underflow from the area is estimated to have been about 36,000 acre-ft a year. Thus, the estimated average annual discharge from the aquifer was about 187,000 acre-ft a year, and this exceeded recharge by about 69,000 acre-ft a year. This overdraft is reflected in a general net decline of the water table of 10 ft in the period 1950-60 and net declines of as much as 30 feet in local areas. Data obtained during this study indicate that about 100,000 acre-ft of water collects in closed depressions on the surface of the High Plains in years when precipitation is normal. Studies of water losses from ponds in selected depressions indicate that between 20 and 80 percent of this loss recharges the groundwater body and the balance is lost to evapotranspiration, principally evaporation. Artificial recharge facilities constructed in the depressions could put at least 50,000 acre-ft of water underground annually that otherwise would be lost to evaporation. Recharging through pits or spreading ponds would cost less

Karst aquifer characterization using geophysical remote sensing of dynamic recharge events

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Effects of a Changing Climate on Seasonal Variation in Natural Recharge of Unconfined Coastal Aquifers

NASA Astrophysics Data System (ADS)

Antonellini, Marco; Nella Mollema, Pauline

2013-04-01

Irregular rainfall patterns throughout the year result in the discontinuous natural recharge of coastal aquifers, which has an effect on the size of freshwater lenses present in sandy deposits. The thickness of the freshwater lenses is important in the context of farmland salinization and coastal ecosystems survival. This study presents numerical models that simulate continuous and discontinuous recharge in sandy coastal aquifers and the thickness of resulting fresh water lenses under current and future climate scenarios. Temperature data for the period 1960-1990 from LOCCLIM FAO and from the IPCC SRES A1b scenario for 2070-2100, have been used to calculate the potential evapotranspiration. Potential recharge was defined as the difference between the precipitation and potential evapotranspiration in twelve locations around the world: Ameland (The Netherlands), Auckland and Wellington (New Zealand), Hong Kong, Ravenna (Italy), Mekong (Vietnam), Mumbai (India), New Jersey (USA), Nile Delta (Egypt), Kobe and Tokyo (Japan), and Singapore. These locations have shallow coastal aquifers along low lying coasts and comparable aquifer structure, which is the result of similar sediment supply and deposition in the Holocene as well as by the sea level changes from the last ice age to the present time. Particular attention has been paid to temporal variations of natural recharge that can vary from continuous recharge throughout the year to discontinuous recharge. The most dramatic reduction in the magnitude of potential annual recharge by the end of this century will occur at lower latitudes (Mumbai, Singapore, Hong Kong and Mekong). The most pronounced change in length of the dry period occurs for Kobe (Japan) and Singapore even though the total annual amount of recharge remains practically the same. The Influence of variable recharge on the size of freshwater lenses surrounded by saline water is simulated with the SEAWAT model. Models where the recharge is applied

Changes in projected spatial and seasonal groundwater recharge in the upper Colorado River Basin

USGS Publications Warehouse

Tillman, Fred; Gangopadhyay, Subhrendu; Pruitt, Tom

2017-01-01

The Colorado River is an important source of water in the western United States, supplying the needs of more than 38 million people in the United States and Mexico. Groundwater discharge to streams has been shown to be a critical component of streamflow in the Upper Colorado River Basin (UCRB), particularly during low-flow periods. Understanding impacts on groundwater in the basin from projected climate change will assist water managers in the region in planning for potential changes in the river and groundwater system. A previous study on changes in basin-wide groundwater recharge in the UCRB under projected climate change found substantial increases in temperature, moderate increases in precipitation, and mostly periods of stable or slight increases in simulated groundwater recharge through 2099. This study quantifies projected spatial and seasonal changes in groundwater recharge within the UCRB from recent historical (1950 to 2015) through future (2016 to 2099) time periods, using a distributed-parameter groundwater recharge model with downscaled climate data from 97 Coupled Model Intercomparison Project Phase 5 (CMIP5) climate projections. Simulation results indicate that projected increases in basin-wide recharge of up to 15% are not distributed uniformly within the basin or throughout the year. Northernmost subregions within the UCRB are projected an increase in groundwater recharge, while recharge in other mainly southern subregions will decline. Seasonal changes in recharge also are projected within the UCRB, with decreases of 50% or more in summer months and increases of 50% or more in winter months for all subregions, and increases of 10% or more in spring months for many subregions.

Areas Contributing Recharge to Wells in the Tafuna-Leone Plain, Tutuila, American Samoa

USGS Publications Warehouse

Izuka, Scot K.; Perreault, Jeff A.; Presley, Todd K.

2007-01-01

To address the concerns about the potential for contamination of drinking-water wells in the Tafuna-Leone Plain, Tutuila, American Samoa, a numerical ground-water flow model was developed and used to delineate areas contributing recharge to the wells (ACRWs). Surveys and analyses were conducted to obtain or compile certain essential hydrogeologic information needed for the model, such as groundwater production statistics, ground-water levels under current production, and an assessment of the distribution of groundwater recharge. The ground-water surveys indicate that total production from all wells in the Tafuna-Leone Plain between 1985 and 2005 averaged 6.1 Mgal/d and showed a gradual increase. A synoptic survey indicates that current water levels in the Tafuna-Leone Plain are highest near its inland boundary, decrease toward the coast, and are slightly depressed in high-production well fields. Ground-water levels showed little effect from the increased production because hydraulic conductivites are high and withdrawal is small relative to recharge. Analysis of ground-water recharge using a soil water-budget analysis indicates that the Tafuna-Leone Plain and adjacent areas receive about 280 Mgal/d of water from rainfall, of which 24 percent runs off to the ocean, 26 percent is removed by evapotranspiration, and 50 percent goes to ground-water recharge. Ground-water recharge per unit area is generally higher at the mountain crests than at the coast, but the highest recharge per unit area is in the mountain-front recharge zone at the juncture between the Tafuna-Leone Plain and the adjacent mountains. Surface water from the mountains also contributes to ground-water recharge in the eastern Tafuna-Leone Plain, in a process analogous to mountain-front recharge described in arid areas. Analysis of stream-gage data indicates that in the mountains of Tutuila, ground water discharges and contributes substantially to the total flow of the streams. In contrast, multiple

Preliminary evaluation of the feasibility of artificial recharge in northern Qater

USGS Publications Warehouse

Vecchioli, John

1976-01-01

Fresh ground water in northern Qatar occurs as a lens in limestone and dolomite of Eocene age. Natural recharge from precipitation averages 17x106 cubic metres per year whereas current discharge averages 26.6x106 cubic metres per year. Depletion of storage is accompanied by a deterioration in quality due to encroachment of salty water from the Gulf and from underlying formations. Artificial recharge with desalted sea water to permit additional agricultural development appears technically feasible but its practicability needs to be examined further. A hydrogeological appraisal including test drilling, geophysical logging, pumping tests, and a recharge test, coupled with engineering analysis of direct surface storage/distribution of desalted sea water versus aquifer storage/distribution, is recommended.

Impact of land use and land cover change on groundwater recharge and quality in the southwestern US

USGS Publications Warehouse

Scanlon, Bridget R.; Reedy, Robert C.; Stonestrom, David A.; Prudic, David E.; Dennehy, Kevin F.

2005-01-01

Humans have exerted large‐scale changes on the terrestrial biosphere, primarily through agriculture; however, the impacts of such changes on the hydrologic cycle are poorly understood. The purpose of this study was to test the hypothesis that the conversion of natural rangeland ecosystems to agricultural ecosystems impacts the subsurface portion of the hydrologic cycle by changing groundwater recharge and flushing salts to underlying aquifers. The hypothesis was examined through point and areal studies investigating the effects of land use/land cover (LU/LC) changes on groundwater recharge and solute transport in the Amargosa Desert (AD) in Nevada and in the High Plains (HP) in Texas, US. Studies use the fact that matric (pore‐water‐pressure) potential and environmental‐tracer profiles in thick unsaturated zones archive past changes in recharging fluxes. Results show that recharge is related to LU/LC as follows: discharge through evapotranspiration (i.e., no recharge; upward fluxes <0.1 mm yr−1) in natural rangeland ecosystems (low matric potentials; high chloride and nitrate concentrations); moderate‐to‐high recharge in irrigated agricultural ecosystems (high matric potentials; low‐to‐moderate chloride and nitrate concentrations) (AD recharge: ∼130–640 mm yr−1); and moderate recharge in nonirrigated (dryland) agricultural ecosystems (high matric potentials; low chloride and nitrate concentrations, and increasing groundwater levels) (HP recharge: ∼9–32 mm yr−1). Replacement of rangeland with agriculture changed flow directions from upward (discharge) to downward (recharge). Recent replacement of rangeland with irrigated ecosystems was documented through downward displacement of chloride and nitrate fronts. Thick unsaturated zones contain a reservoir of salts that are readily mobilized under increased recharge related to LU/LC changes, potentially degrading groundwater quality. Sustainable land use requires quantitative

Chloride mass-balance method for estimating ground water recharge in arid areas: examples from western Saudi Arabia

NASA Astrophysics Data System (ADS)

Bazuhair, Abdulghaffar S.; Wood, Warren W.

1996-11-01

The chloride mass-balance method, which integrates time and aerial distribution of ground water recharge, was applied to small alluvial aquifers in the wadi systems of the Asir and Hijaz mountains in western Saudi Arabia. This application is an extension of the method shown to be suitable for estimating recharge in regional aquifers in semi-arid areas. Because the method integrates recharge in time and space it appears to be, with certain assumptions, particularly well suited for and areas with large temporal and spatial variation in recharge. In general, recharge was found to be between 3 to 4% of precipitation — a range consistent with recharge rates found in other and and semi-arid areas of the earth.

Chloride mass-balance method for estimating ground water recharge in arid areas: Examples from western Saudi Arabia

USGS Publications Warehouse

Bazuhair, A.S.; Wood, W.W.

1996-01-01

The chloride mass-balance method, which integrates time and aerial distribution of ground water recharge, was applied to small alluvial aquifers in the wadi systems of the Asir and Hijaz mountains in western Saudi Arabia. This application is an extension of the method shown to be suitable for estimating recharge in regional aquifers in semi-arid areas. Because the method integrates recharge in time and space it appears to be, with certain assumptions, particularly well suited for and areas with large temporal and spatial variation in recharge. In general, recharge was found to be between 3 to 4% of precipitation - a range consistent with recharge rates found in other arid and semi-arid areas of the earth.

Recent and ancient recharge deciphered by multi-dating tracer technique

NASA Astrophysics Data System (ADS)

Dogramaci, Shawan; Cook, Peter; Mccallum, Jimes; Purtchert, Roland

2017-04-01

Determining groundwater residence time from environmental tracer concentrations obtained from open bores or long screened intervals is fraught with difficulty because the sampled water represents variety of ages. Information on the distribution of groundwater age is commonly obtained by measuring more than one tracer. We examined the use of the multi-tracer technique representing different time frames (39Ar, 85Kr, 14C, 3H, CFC 11- CFC-12 CFC-113, SF6 and Cl,) to decipher the groundwater ages sampled from long screened bores in a regional aquifer in the Pilbara region of northwest Australia. We then applied a technique that assumes limited details of the form of the age distribution. Tracer concentrations suggest that groundwater samples are a mixture of young and old water - the former is inferred to represent localised recharge from an adjacent creek, and the latter to be diffuse recharge. Using our method, we were able to identify distinct age components in the groundwater. The results suggest the presence of four distinct age groups; zero and 20 years, 50 to 100 years, 100 to 600 years and approximately 1000 years old. These relatively high recharge events were consistent with local recharge sources (50-100 years) and confirmed by palaeo-climate record obtained from lake sediments. We found that although the ages of these components were well constrained, the relative proportions of each component was highly sensitive to errors of environmental tracer data. Our results show that the method we implemented can identify distinct age groups in groundwater samples without prior knowledge of the age distribution. The presence of distinct recharge times gives insight into groundwater flow conditions over long periods of time.

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.

Optimization of groundwater artificial recharge systems using a genetic algorithm: a case study in Beijing, China

NASA Astrophysics Data System (ADS)

Hao, Qichen; Shao, Jingli; Cui, Yali; Zhang, Qiulan; Huang, Linxian

2018-05-01

An optimization approach is used for the operation of groundwater artificial recharge systems in an alluvial fan in Beijing, China. The optimization model incorporates a transient groundwater flow model, which allows for simulation of the groundwater response to artificial recharge. The facilities' operation with regard to recharge rates is formulated as a nonlinear programming problem to maximize the volume of surface water recharged into the aquifers under specific constraints. This optimization problem is solved by the parallel genetic algorithm (PGA) based on OpenMP, which could substantially reduce the computation time. To solve the PGA with constraints, the multiplicative penalty method is applied. In addition, the facilities' locations are implicitly determined on the basis of the results of the recharge-rate optimizations. Two scenarios are optimized and the optimal results indicate that the amount of water recharged into the aquifers will increase without exceeding the upper limits of the groundwater levels. Optimal operation of this artificial recharge system can also contribute to the more effective recovery of the groundwater storage capacity.

GIS for the Assessment of the Groundwater Recharge Potential Zone

NASA Astrophysics Data System (ADS)

Lee, C.; Yeh, H.; Chen, J.; Hsu, K.

2008-12-01

Water resources in Taiwan are unevenly distributed in spatial and temporal domains. Effectively utilizing the water resources is an imperative task due to climate change. At present, groundwater contributes 34% of the total annual water supply and is an important fresh water resource. However, over-exploitation has decreased groundwater availability and has led to land subsidence. Assessing the potential zone of groundwater recharge is extremely important for the protection of water quality and the management of groundwater systems. The Chih-Pen Creek basin in eastern Taiwan is examined in this study to assess its groundwater resources potential. Remote sensing and the Geographical Information System (GIS) are used to integrate five contributing factors: lithology, land cover/land use, lineaments, drainage, and slope. The weights of factors contributing to the groundwater recharge are derived using aerial photos, geology maps, a land use database, and field verification. The resultant map of the groundwater potential zone demonstrates that the highest recharge potential area is located towards the downstream regions in the basin because of the high infiltration rates caused by gravelly sand and agricultural land use in these regions. In contrast, the least effective recharge potential area is in upstream regions due to the low infiltration of limestone.

An analytical formulation of two‐dimensional groundwater dispersion induced by surficial recharge variability

USGS Publications Warehouse

Swain, Eric D.; Chin, David A.

2003-01-01

A predominant cause of dispersion in groundwater is advective mixing due to variability in seepage rates. Hydraulic conductivity variations have been extensively researched as a cause of this seepage variability. In this paper the effect of variations in surface recharge to a shallow surficial aquifer is investigated as an important additional effect. An analytical formulation has been developed that relates aquifer parameters and the statistics of recharge variability to increases in the dispersivity. This is accomplished by solving Fourier transforms of the small perturbation forms of the groundwater flow equations. Two field studies are presented in this paper to determine the statistics of recharge variability for input to the analytical formulation. A time series of water levels at a continuous groundwater recorder is used to investigate the temporal statistics of hydraulic head caused by recharge, and a series of infiltrometer measurements are used to define the spatial variability in the recharge parameters. With these field statistics representing head fluctuations due to recharge, the analytical formulation can be used to compute the dispersivity without an explicit representation of the recharge boundary. Results from a series of numerical experiments are used to define the limits of this analytical formulation and to provide some comparison. A sophisticated model has been developed using a particle‐tracking algorithm (modified to account for temporal variations) to estimate groundwater dispersion. Dispersivity increases of 9 percent are indicated by the analytical formulation for the aquifer at the field site. A comparison with numerical model results indicates that the analytical results are reasonable for shallow surficial aquifers in which two‐dimensional flow can be assumed.

Irrigated agriculture and future climate change effects on groundwater recharge, northern High Plains aquifer, USA

USGS Publications Warehouse

Lauffenburger, Zachary H.; Gurdak, Jason J.; Hobza, Christopher M.; Woodward, Duane; Wolf, Cassandra

2018-01-01

Understanding the controls of agriculture and climate change on recharge rates is critically important to develop appropriate sustainable management plans for groundwater resources and coupled irrigated agricultural systems. In this study, several physical (total potential (ψT) time series) and chemical tracer and dating (3H, Cl−, Br−, CFCs, SF6, and 3H/3He) methods were used to quantify diffuse recharge rates beneath two rangeland sites and irrigation recharge rates beneath two irrigated corn sites along an east-west (wet-dry) transect of the northern High Plains aquifer, Platte River Basin, central Nebraska. The field-based recharge estimates and historical climate were used to calibrate site-specific Hydrus-1D models, and irrigation requirements were estimated using the Crops Simulation Model (CROPSIM). Future model simulations were driven by an ensemble of 16 global climate models and two global warming scenarios to project a 2050 climate relative to the historical baseline 1990 climate, and simulate changes in precipitation, irrigation, evapotranspiration, and diffuse and irrigation recharge rates. Although results indicate statistical differences between the historical variables at the eastern and western sites and rangeland and irrigated sites, the low warming scenario (+1.0 °C) simulations indicate no statistical differences between 2050 and 1990. However, the high warming scenarios (+2.4 °C) indicate a 25% and 15% increase in median annual evapotranspiration and irrigation demand, and decreases in future diffuse recharge by 53% and 98% and irrigation recharge by 47% and 29% at the eastern and western sites, respectively. These results indicate an important threshold between the low and high warming scenarios that if exceeded could trigger a significant bidirectional shift in 2050 hydroclimatology and recharge gradients. The bidirectional shift is that future northern High Plains temperatures will resemble present central High Plains

The Hydrometeorological DREAM: A Daily REcharge Assessment Model, for the Israeli Western Mountain Aquifer

NASA Astrophysics Data System (ADS)

Sheffer, N. A.; Dafny, E.; Gvirtzman, H.; Frumkin, A.; Navon, S.; Morin, E.

2008-05-01

The western part of the Israeli Mountain Aquifer (WMA) supplies 360-400 MCM/y of fresh water to the Israeli water budget, which is approximately 20% of the total consumption. The annually recharge to the WMA is considered to be 25-35% of annual rainfall. The high variability in recharge to the WMA is due to spatial and temporal differences in the rain contributing to the aquifer. Different winters producing the same amount of rain may contribute differently to the aquifer due to the locations of the storms, intensity, duration, dry spells between successive rain events, etc. Moreover, besides the climatic-meteorological factors, the recharge is dependent also on geographical factors, such as lithology, pedology, land-use, slope gradient, slope direction etc. The need for a robust reliable Hydrometeorological Daily basis REcharge Assessment Model (Hydrometeorological DREAM) brought us to develop a model with a relatively high spatial and temporal resolution. The concept is based on a relatively simple water budget that states that rainfall over land is added to the soil, and removed later on by means of evapotranspiration, recharge and runoff. The method in use to date at the Hydrological Service for estimating recharge to the WMA is based on an annual regression curve that can be implemented only after the total annual rainfall is known. The DREAM is a near real time estimator of recharge to the WMA using daily rainfall and pan evaporation data. Comparison of the DREAM results with the annual regression curve show a high agreement on an annual basis. The improvements introduced by the DREAM are: 1) Near real time daily values of infiltration, as opposed to calculated annual values established after the rain season is over. 2) High spatial resolution. The DREAM produces daily recharge values in more than 3000 mesh points throughout the 2200 km2 of recharge area. By linking the DREAM output as input to a hydrogeological model (such as FEFLOW, MODFLOW etc.) a

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.

Nonflammable gel electrolyte containing alkyl phosphate for rechargeable lithium batteries

NASA Astrophysics Data System (ADS)

Yoshimoto, Nobuko; Niida, Yoshihiro; Egashira, Minato; Morita, Masayuki

A nonflammable polymeric gel electrolyte has been developed for rechargeable lithium battery systems. The gel film consists of poly(vinylidenefluoride- co-hexafluoropropylene) (PVdF-HFP) swollen with lithium hexafluorophosphate (LiPF 6) solution in ternary solvent containing trimethyl phosphate (TMP). High ionic conductivity of 6.2 mS cm -1 at 20 °C was obtained for the gel electrolyte consisting of 0.8 M LiPF 6/EC + DEC + TMP (55:25:20) with PVdF-HFP, which is comparable to that of the liquid electrolyte containing the same electrolytic salt. Addition of a small amount of vinylene carbonate (VC) in the gel electrolyte improved the rechargeability of a graphite electrode. The rechargeable capacity of the graphite in the gel containing VC was ca. 300 mAh g -1, which is almost the same as that in a conventional liquid electrolyte system.

Early Late Triassic Subduction in the Northern Branch of Neotethys?: Petrological and Paleontological Constraints from the middle Carnian basalts in the Lycian Nappes

NASA Astrophysics Data System (ADS)

Sayit, K.; Göncüoglu, M. C.; Tekin, U. K.

2015-12-01

The Lycian Nappes, SW Anatolia, are represented by a stack of thrust sheets derived from the northern branch of Neotethys (i.e. Izmir-Ankara Ocean) and the northern margin of the Tauride-Anatolide platform. The Turunç Unit, which is now preserved within a tectonic slice of the Lycian Nappes, includes among others the Neotethys-derived basalt blocks with pelagic intra-pillow carbonate infillings of middle Carnian age (early Late Triassic). Here, we focus on the geochemistry of the Turunç basalts to shed light into their petrogenetic evolution within the Neotethyan framework. Immobile trace element systematics indicate that the Turunç lavas are sub-alkaline basalts, with geochemical signatures resembling to those generated above subduction zones. Detailed examination of the Turunç volcanics reveals two chemical groups. Both groups are variably enriched in Th and La relative to Nb, and exhibit depleted Zr and Hf contents relative to N-MORB. Of the two groups, however, Group 2 is more enriched in Th, but with a similar Nb content, which results in higher Th/Nb ratios (0.21-0.27) compared to those of Group 1 (0.08-0.11). Both groups reflect similar REE systematics; they display marked enrichment in LREE relative to HREE ([La/Yb]N = 4.8-8.9). Trace element characteristics of the Turunç basalts indicate that their mantle source has been modified by slab-derived component(s). Taking into account that the Turunc Unit includes no continent-derived detritus, we suggest that the Turunç lavas represent fragments of a Late Triassic island arc formed on the Neotethyan oceanic lithosphere. This may further imply that the Neotethyan oceanic lithosphere had already been formed by the early Late Triassic, thus suggesting a pre-early Late Triassic oceanization of the northern branch of Neotethys.

Inorganic rechargeable non-aqueous cell

DOEpatents

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.

Testing an automated method to estimate ground-water recharge from streamflow records

USGS Publications Warehouse

Rutledge, A.T.; Daniel, C.C.

1994-01-01

The computer program, RORA, allows automated analysis of streamflow hydrographs to estimate ground-water recharge. Output from the program, which is based on the recession-curve-displacement method (often referred to as the Rorabaugh method, for whom the program is named), was compared to estimates of recharge obtained from a manual analysis of 156 years of streamflow record from 15 streamflow-gaging stations in the eastern United States. Statistical tests showed that there was no significant difference between paired estimates of annual recharge by the two methods. Tests of results produced by the four workers who performed the manual method showed that results can differ significantly between workers. Twenty-two percent of the variation between manual and automated estimates could be attributed to having different workers perform the manual method. The program RORA will produce estimates of recharge equivalent to estimates produced manually, greatly increase the speed od analysis, and reduce the subjectivity inherent in manual analysis.

Heat flux from magmatic hydrothermal systems related to availability of fluid recharge

USGS Publications Warehouse

Harvey, M. C.; Rowland, J.V.; Chiodini, G.; Rissmann, C.F.; Bloomberg, S.; Hernandez, P.A.; Mazot, A.; Viveiros, F.; Werner, Cynthia A.

2015-01-01

Magmatic hydrothermal systems are of increasing interest as a renewable energy source. Surface heat flux indicates system resource potential, and can be inferred from soil CO2 flux measurements and fumarole gas chemistry. Here we compile and reanalyze results from previous CO2 flux surveys worldwide to compare heat flux from a variety of magma-hydrothermal areas. We infer that availability of water to recharge magmatic hydrothermal systems is correlated with heat flux. Recharge availability is in turn governed by permeability, structure, lithology, rainfall, topography, and perhaps unsurprisingly, proximity to a large supply of water such as the ocean. The relationship between recharge and heat flux interpreted by this study is consistent with recent numerical modeling that relates hydrothermal system heat output to rainfall catchment area. This result highlights the importance of recharge as a consideration when evaluating hydrothermal systems for electricity generation, and the utility of CO2 flux as a resource evaluation tool.

Lithologic influences on groundwater recharge through incised glacial till from profile to regional scales: Evidence from glaciated Eastern Nebraska

USGS Publications Warehouse

Gates, John B.; Steele, Gregory V.; Nasta, Paolo; Szilagyi, Jozsef

2014-01-01

Variability in sediment hydraulic properties associated with landscape depositional and erosional features can influence groundwater recharge processes by affecting soil-water storage and transmission. This study considers recharge to aquifers underlying river-incised glaciated terrain where the distribution of clay-rich till is largely intact in upland locations but has been removed by alluvial erosion in stream valleys. In a stream-dissected glacial region in eastern Nebraska (Great Plains region of the United States), recharge estimates were developed for nested profile, aquifer, and regional scales using unsaturated zone profile measurements (matric potentials, Cl- and 3H), groundwater tracers (CFC-12 and SF6), and a remote sensing-assisted water balance model. Results show a consistent influence of till lithology on recharge rates across nested spatial scales despite substantial uncertainty in all recharge estimation methods, suggesting that minimal diffuse recharge occurs through upland glacial till lithology whereas diffuse recharge occurs in river valleys where till is locally absent. Diffuse recharge is estimated to account for a maximum of 61% of total recharge based on comparison of diffuse recharge estimated from the unsaturated zone (0-43 mm yr-1) and total recharge estimated from groundwater tracers (median 58 mm yr-1) and water balance modeling (median 56 mm yr-1). The results underscore the importance of lithologic controls on the distributions of both recharge rates and mechanisms.

A time series approach to inferring groundwater recharge using the water table fluctuation method

NASA Astrophysics Data System (ADS)

Crosbie, Russell S.; Binning, Philip; Kalma, Jetse D.

2005-01-01

The water table fluctuation method for determining recharge from precipitation and water table measurements was originally developed on an event basis. Here a new multievent time series approach is presented for inferring groundwater recharge from long-term water table and precipitation records. Additional new features are the incorporation of a variable specific yield based upon the soil moisture retention curve, proper accounting for the Lisse effect on the water table, and the incorporation of aquifer drainage so that recharge can be detected even if the water table does not rise. A methodology for filtering noise and non-rainfall-related water table fluctuations is also presented. The model has been applied to 2 years of field data collected in the Tomago sand beds near Newcastle, Australia. It is shown that gross recharge estimates are very sensitive to time step size and specific yield. Properly accounting for the Lisse effect is also important to determining recharge.

Dug Well Recharge Method for Insitu Mitigation of Fluoride Contamination in Groundwater

NASA Astrophysics Data System (ADS)

Ganesan, G.; Lakshmanan, E.; Gunalan, J.

2016-12-01

Groundwater with fluoride concentration exceeding 1.5 mg/l is not suitable for drinking water supply as it may cause health issues such as dental and skeletal fluorosis to humans. Several million people around the world has been affected by fluorosis. The objective of the study is to mitigate the problem of fluoride contamination in groundwater by increasing groundwater recharge through a dug well recharge system. The study was carried out in a part of Vaniyar river basin, northwest Tamil Nadu, India where fluorosis is prevalent. A cylindrical pit of 1m diameter and 1.5 m height was constructed during May 2014 at a distance of about 4 m from a dug well existing in this area. This cylindrical pit was divided into 3 compartments and one of them was filled with gravel and one with sand. The third compartment was kept empty for inspection and maintenance. The rainfall collected in a funnel shaped depression was allowed to pass through these compartments to discharge in the nearby dug well through a pipe. The concentration of the fluoride in groundwater from this well was had been monitoring on bi-monthly basis from the year 2012 to 2014. After construction of dug well recharge system, the groundwater level has raised by about 5 m and the fluoride concentration has decreased from 3.1 mg/l to 1.44 mg/l due to recharge. The concentration of fluoride and groundwater level is being monitored on daily basis from June 2014. It is evident that the recharge system constructed is working well and the concentration of fluoride in groundwater is within the permissible limit. The advantage of this dug well recharge system is its low cost and the ease of implementation. Thus this pilot study on dug well recharge system demonstrated it's potential in reducing the concentration of fluoride in groundwater which is more beneficial to the society as they cannot afford the well proven water treatment methods.

Changes in Projected Spatial and Seasonal Groundwater Recharge in the Upper Colorado River Basin.

PubMed

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

2017-07-01

The Colorado River is an important source of water in the western United States, supplying the needs of more than 38 million people in the United States and Mexico. Groundwater discharge to streams has been shown to be a critical component of streamflow in the Upper Colorado River Basin (UCRB), particularly during low-flow periods. Understanding impacts on groundwater in the basin from projected climate change will assist water managers in the region in planning for potential changes in the river and groundwater system. A previous study on changes in basin-wide groundwater recharge in the UCRB under projected climate change found substantial increases in temperature, moderate increases in precipitation, and mostly periods of stable or slight increases in simulated groundwater recharge through 2099. This study quantifies projected spatial and seasonal changes in groundwater recharge within the UCRB from recent historical (1950 to 2015) through future (2016 to 2099) time periods, using a distributed-parameter groundwater recharge model with downscaled climate data from 97 Coupled Model Intercomparison Project Phase 5 (CMIP5) climate projections. Simulation results indicate that projected increases in basin-wide recharge of up to 15% are not distributed uniformly within the basin or throughout the year. Northernmost subregions within the UCRB are projected an increase in groundwater recharge, while recharge in other mainly southern subregions will decline. Seasonal changes in recharge also are projected within the UCRB, with decreases of 50% or more in summer months and increases of 50% or more in winter months for all subregions, and increases of 10% or more in spring months for many subregions. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

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

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.

Method of estimating natural recharge to the Edwards Aquifer in the San Antonio area, Texas

USGS Publications Warehouse

Puente, Celso

1978-01-01

The principal errors in the estimates of annual recharge are related to errors in estimating runoff in ungaged areas, which represent about 30 percent of the infiltration area. The estimated long-term average annual recharge in each basin, however, is probably representative of the actual recharge because the averaging procedure tends to cancel out the major errors.

77 FR 56253 - Ninth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems-Small...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-12

... 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal Aviation... 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY: The FAA is..., Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. DATES: The meeting will be held...

77 FR 66084 - Tenth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems-Small...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-01

... 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal Aviation... 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY: The FAA is..., Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. DATES: The meeting will be held...

Book review: 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. Briefly stated, recharge is downward flux across the water table. The term “groundwater recharge” can refer either to the multiple interacting processes generating and controlling the flux or to the fluxR itself. When referring to flux, R can represent either (1) a value integrated over large areas and long periods of time or (2) a point value, or instantaneous flux density, that varies erratically as well as continuously in time and space. Knowing how R is distributed through space and time is required for understanding the dynamics of groundwater flow and transport in any watershed, aquifer, or selected domain of interest and for understanding heads, flow paths, and discharges to streams, wetlands, and other surface water bodies. Clearly among the most important of hydrologic fluxes, R is also one of the most difficult to measure. Advancements in hydrologic science have proceeded surprisingly in lockstep with advances in determining R.

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.

Karst Aquifer in Qatar and its bearing on Natural Rainfall Recharge

NASA Astrophysics Data System (ADS)

Baalousha, Husam; Ackerer, Philippe

2017-04-01

Qatar is an arid country with little rainfall and high evaporation. Surface water is non-existent so aquifer is the only source of natural water. The annual long-term averages of rainfall and evaporation are 80 mm and more than 2000 mm, respectively. Despite the low rainfall and high evaporation, natural recharge from rainfall occurs at an average of approximately 50 million m3 per year. Rainfall recharge in Qatar takes in land depressions that occur all over the country. These depressions are a result of land collapse due to sinkholes and cavity in the limestone formation. In the northern part of the country, karst features occur as a result of dissolution of limestone, which leads to land depressions. Results of this study shows groundwater recharge occurs in land depression areas, especially in the northern part of the country, where surface runoff accumulates in these land depressions and recharges the aquifer. This paper was made possible by NPRP grant # [NPRP 9-030-1-008] from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the author[s]."

Interactions between deep bedrock aquifers and surface water in function of recharge and topography: a numerical study

NASA Astrophysics Data System (ADS)

Goderniaux, P.; Davy, P.; Le Borgne, T.; Bresciani, E.; Jimenez-Martinez, J.

2011-12-01

In crystalline rock regions, such as Brittany (France), important reserves of groundwater into deep fractured aquifers are increasingly used and provide high quality water compared to shallow aquifers which can be subject to agricultural contamination. However, recharge processes of these deep aquifers and interactions with surface water are not yet fully understood. In some areas, intensive pumping is carried out without guarantee of the resource quantity and quality. Understanding these processes is crucial for sustainable management of the resource. In this study, we study how deep groundwater fluxes, pathways, ages, and river-aquifer interactions vary according to recharge. We assume that water flowing from the ground surface is distributed between shallow more permeable layers and deep layers. This repartition mostly depends on recharge rates. With high recharge, groundwater levels are high and subsurface streamlines are relatively short between recharge areas and existing draining rivers, which constitutes a very dense network. Therefore, most of the groundwater fluxes occur through the more permeable shallow layers. With low recharge, groundwater levels are lower, and river and shallow permeable levels are partly disconnected from each other. This induces a general increase of the groundwater streamlines length from the recharge areas to more sporadic discharge areas, and more fluxes occur through the deep layers. Recharge conditions and river-aquifer interactions have changed over the last thousands of years, due to change in precipitation, temperatures, existence of permafrost, etc. They have strongly influenced deep groundwater fluxes and can explain current groundwater age and flux distribution. To study these interactions, a regional-scale finite difference flow model was implemented. The model covers an area of 1400 km 2 , a depth of 1 km, and the topography is characteristic of Brittany. As rivers are mainly fed by groundwater drainage, seepages faces

76 FR 70531 - Fifth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems-Small...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-14

... 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal Aviation..., Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 225, Rechargeable Lithium Battery and...

Baseline water quality and preliminary effects of artificial recharge on ground water, south-central Kansas, 1995-98

USGS Publications Warehouse

Ziegler, Andrew C.; Christensen, Victoria G.; Ross, Heather C.

1999-01-01

To investigate the feasbility of artificial recharge as a method of meeting future water-supply needs and to protect the Equus Beds aquifer from saltwater intrusion from natural and anthropogenic sources to the west, the Equus Beds Ground-Water Recharge from Demonstration Project was begun in 1995. The project is a cooperative effort between the city of Wichita and the Bureau of Reclamation, U.S. Department of the Interior. During the project, high flows from the Little Arkansas River are captured and recharged into the Equus Beds aquifer through recharge basins, a trench, or a recharge well, located at two recharge sites near Halstead and Sedgwick, Kansas. To document baseline concentrations and compatibility of stream (recharge) and aquifer water, the U.S. Geological Survey collected water samples from February 1995 through August 1998. These samples were analyzed for dissolved solids, total and dissolved inorganic constituents, nutrients, organic and volatile organic compounds, radionuclides, and bacteria. Results of baseline sampling indicated that the primary constituents of concern for recharge were sodium, chloride, nitrite plus nitrate, iron and manganese, total coliform bacteria, and atrazine. Chloride and atrazine were of particular concern because concentrations of these constituents in water from the Little Arkansas River frequently exceeded regulatory criteria. The Little Arkansas River is used as the source water for recharge. The U.S. Environmental Protection Agency Secondary Maximum Contaminant Level for chloride is 250 mg/L (milligrams per liter), and the Maximum Contaminant Level for atrazine is 3.0 ?g/L (micrograms per liter) as an annual mean. Baseline concentrations of chloride in surface water ranged from 8.0 to 400 ?g/L. Baseline concentrations of atrazine in surface water ranged from less than 0.10 to 46 ?g/L. Concentrations of chloride and atrazine have increased in water from some of the wells at both the Halstead and Sedgwick recharge

Assessing the groundwater recharge under various irrigation schemes in Central Taiwan

NASA Astrophysics Data System (ADS)

Chen, Shih-Kai; Jang, Cheng-Shin; Lin, Zih-Ciao; Tsai, Cheng-Bin

2014-05-01

The flooded paddy fields can be considered as a major source of groundwater recharge in Central Taiwan. The risk of rice production has increased notably due to climate change in this area. To respond to agricultural water shortage caused by climate change without affecting rice yield in the future, the application of water-saving irrigation is the substantial resolution. The System of Rice Intensification (SRI) was developed as a set of insights and practices used in growing irrigated rice. Based on the water-saving irrigation practice of SRI, impacts of the new methodology on the reducing of groundwater recharge were assessed in central Taiwan. The three-dimensional finite element groundwater model (FEMWATER) with the variable boundary condition analog functions, was applied in simulating groundwater recharge under different irrigation schemes. According to local climatic and environmental characteristics associated with SRI methodology, the change of infiltration rate was evaluated and compared with the traditional irrigation schemes, including continuous irrigation and rotational irrigation scheme. The simulation results showed that the average infiltration rate in the rice growing season decreased when applying the SRI methodology, and the total groundwater recharge amount of SRI with a 5-day irrigation interval reduced 12% and 9% compared with continuous irrigation (6cm constant ponding water depth) and rotational scheme (5-day irrigation interval with 6 cm initial ponding water depth), respectively. The results could be used as basis for planning long-term adaptive water resource management strategies to climate change in Central Taiwan. Keywords: SRI, Irrigation schemes, Groundwater recharge, Infiltration

Impact de la preparation des anodes crues et des conditions de cuisson sur la fissuration dans des anodes denses

NASA Astrophysics Data System (ADS)

Amrani, Salah

La fabrication de l'aluminium est realisee dans une cellule d'electrolyse, et cette operation utilise des anodes en carbone. L'evaluation de la qualite de ces anodes reste indispensable avant leur utilisation. La presence des fissures dans les anodes provoque une perturbation du procede l'electrolyse et une diminution de sa performance. Ce projet a ete entrepris pour determiner l'impact des differents parametres de procedes de fabrication des anodes sur la fissuration des anodes denses. Ces parametres incluent ceux de la fabrication des anodes crues, des proprietes des matieres premieres et de la cuisson. Une recherche bibliographique a ete effectuee sur tous les aspects de la fissuration des anodes en carbone pour compiler les travaux anterieurs. Une methodologie detaillee a ete mise au point pour faciliter le deroulement des travaux et atteindre les objectifs vises. La majorite de ce document est reservee pour la discussion des resultats obtenus au laboratoire de l'UQAC et au niveau industriel. Concernant les etudes realisees a l'UQAC, une partie des travaux experimentaux est reservee a la recherche des differents mecanismes de fissuration dans les anodes denses utilisees dans l'industrie d'aluminium. L'approche etait d'abord basee sur la caracterisation qualitative du mecanisme de la fissuration en surface et en profondeur. Puis, une caracterisation quantitative a ete realisee pour la determination de la distribution de la largeur de la fissure sur toute sa longueur, ainsi que le pourcentage de sa surface par rapport a la surface totale de l'echantillon. Cette etude a ete realisee par le biais de la technique d'analyse d'image utilisee pour caracteriser la fissuration d'un echantillon d'anode cuite. L'analyse surfacique et en profondeur de cet echantillon a permis de voir clairement la formation des fissures sur une grande partie de la surface analysee. L'autre partie des travaux est basee sur la caracterisation des defauts dans des echantillons d'anodes crues

Sensitivity of quantitative groundwater recharge estimates to volumetric and distribution uncertainty in rainfall forcing products

NASA Astrophysics Data System (ADS)

Werner, Micha; Westerhoff, Rogier; Moore, Catherine

2017-04-01

Quantitative estimates of recharge due to precipitation excess are an important input to determining sustainable abstraction of groundwater resources, as well providing one of the boundary conditions required for numerical groundwater modelling. Simple water balance models are widely applied for calculating recharge. In these models, precipitation is partitioned between different processes and stores; including surface runoff and infiltration, storage in the unsaturated zone, evaporation, capillary processes, and recharge to groundwater. Clearly the estimation of recharge amounts will depend on the estimation of precipitation volumes, which may vary, depending on the source of precipitation data used. However, the partitioning between the different processes is in many cases governed by (variable) intensity thresholds. This means that the estimates of recharge will not only be sensitive to input parameters such as soil type, texture, land use, potential evaporation; but mainly to the precipitation volume and intensity distribution. In this paper we explore the sensitivity of recharge estimates due to difference in precipitation volumes and intensity distribution in the rainfall forcing over the Canterbury region in New Zealand. We compare recharge rates and volumes using a simple water balance model that is forced using rainfall and evaporation data from; the NIWA Virtual Climate Station Network (VCSN) data (which is considered as the reference dataset); the ERA-Interim/WATCH dataset at 0.25 degrees and 0.5 degrees resolution; the TRMM-3B42 dataset; the CHIRPS dataset; and the recently releases MSWEP dataset. Recharge rates are calculated at a daily time step over the 14 year period from the 2000 to 2013 for the full Canterbury region, as well as at eight selected points distributed over the region. Lysimeter data with observed estimates of recharge are available at four of these points, as well as recharge estimates from the NGRM model, an independent model

Managed aquifer recharge through off-season irrigation in agricultural regions

USGS Publications Warehouse

Niswonger, Richard; Morway, Eric D.; Triana, Enrique; Huntington, Justin L.

2017-01-01

Options for increasing reservoir storage in developed regions are limited and prohibitively expensive. Projected increases in demand call for new long-term water storage to help sustain agriculture, municipalities, industry, and ecological services. Managed aquifer recharge (MAR) is becoming an integral component of water resources around the world. However, MAR faces challenges, including infrastructure costs, difficulty in enhancing recharge, water quality issues, and lack of available water supplies. Here we examine, through simulation modeling of a hypothetical agricultural subbasin in the western U.S., the potential of agricultural managed aquifer recharge (Ag-MAR) via canal seepage and off-season field irrigation. Weather phenomenon in many regions around the world exhibit decadal and other multiyear cycles of extreme precipitation. An ongoing challenge is to develop approaches to store greater amounts of water during these events. Simulations presented herein incorporate Ag-MAR programs and demonstrate that there is potential to enhance regional recharge by 7–13%, increase crop consumptive use by 9–12%, and increase natural vegetation consumption by 20–30%, where larger relative increases occur for lower aquifer hydraulic conductivity and higher specific yield values. Annual increases in groundwater levels were 7 m, and sustained levels following several years of drought were greater than 2 m. Results demonstrate that Ag-MAR has great potential to enhance long-term sustainability of water resources in agricultural basins.

Managed aquifer recharge through off-season irrigation in agricultural regions

NASA Astrophysics Data System (ADS)

Niswonger, Richard G.; Morway, Eric D.; Triana, Enrique; Huntington, Justin L.

2017-08-01

Options for increasing reservoir storage in developed regions are limited and prohibitively expensive. Projected increases in demand call for new long-term water storage to help sustain agriculture, municipalities, industry, and ecological services. Managed aquifer recharge (MAR) is becoming an integral component of water resources around the world. However, MAR faces challenges, including infrastructure costs, difficulty in enhancing recharge, water quality issues, and lack of available water supplies. Here we examine, through simulation modeling of a hypothetical agricultural subbasin in the western U.S., the potential of agricultural managed aquifer recharge (Ag-MAR) via canal seepage and off-season field irrigation. Weather phenomenon in many regions around the world exhibit decadal and other multiyear cycles of extreme precipitation. An ongoing challenge is to develop approaches to store greater amounts of water during these events. Simulations presented herein incorporate Ag-MAR programs and demonstrate that there is potential to enhance regional recharge by 7-13%, increase crop consumptive use by 9-12%, and increase natural vegetation consumption by 20-30%, where larger relative increases occur for lower aquifer hydraulic conductivity and higher specific yield values. Annual increases in groundwater levels were 7 m, and sustained levels following several years of drought were greater than 2 m. Results demonstrate that Ag-MAR has great potential to enhance long-term sustainability of water resources in agricultural basins.

Two-Dimensional Metal Oxide Nanomaterials for Next-Generation Rechargeable Batteries.

PubMed

Mei, Jun; Liao, Ting; Kou, Liangzhi; Sun, Ziqi

2017-12-01

The exponential increase in research focused on two-dimensional (2D) metal oxides has offered an unprecedented opportunity for their use in energy conversion and storage devices, especially for promising next-generation rechargeable batteries, such as lithium-ion batteries (LIBs) and sodium-ion batteries (NIBs), as well as some post-lithium batteries, including lithium-sulfur batteries, lithium-air batteries, etc. The introduction of well-designed 2D metal oxide nanomaterials into next-generation rechargeable batteries has significantly enhanced the performance of these energy-storage devices by providing higher chemically active interfaces, shortened ion-diffusion lengths, and improved in-plane carrier-/charge-transport kinetics, which have greatly promoted the development of nanotechnology and the practical application of rechargeable batteries. Here, the recent progress in the application of 2D metal oxide nanomaterials in a series of rechargeable LIBs, NIBs, and other post lithium-ion batteries is reviewed relatively comprehensively. Current opportunities and future challenges for the application of 2D nanomaterials in energy-storage devices to achieve high energy density, high power density, stable cyclability, etc. are summarized and outlined. It is believed that the integration of 2D metal oxide nanomaterials in these clean energy devices offers great opportunities to address challenges driven by increasing global energy demands. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

A validation of the 3H/3He method for determining groundwater recharge

NASA Astrophysics Data System (ADS)

Solomon, D. K.; Schiff, S. L.; Poreda, R. J.; Clarke, W. B.

1993-09-01

Tritium and He isotopes have been measured at a site where groundwater flow is nearly vertical for a travel time of 100 years and where recharge rates are spatially variable. Because the mid-1960s 3H peak (arising from aboveground testing of thermonuclear devices) is well-defined, the vertical groundwater velocity is known with unusual accuracy at this site. Utilizing 3H and its stable daughter 3He to determine groundwater ages, we compute a recharge rate of 0.16 m/yr, which agrees to within about 5% of the value based on the depth of the 3H peak (measured both in 1986 and 1991) and two-dimensional modeling in an area of high recharge. Zero 3H/3He age occurs at a depth that is approximately equal to the average depth of the annual low water table, even though the capillary fringe extends to land surface during most of the year at the study site. In an area of low recharge (0.05 m/yr) where the 3H peak (and hence the vertical velocity) is also well-defined, the 3H/3He results could not be used to compute recharge because samples were not collected sufficiently far above the 3H peak; however, modeling indicates that the 3H/3He age gradient near the water table is an accurate measure of vertical velocities in the low-recharge area. Because 3H and 3He have different diffusion coefficients, and because the amount of mechanical mixing is different in the area of high recharge than in the low-recharge area, we have separated the dispersive effects of mechanical mixing from molecular diffusion. We estimate a longitudinal dispersivity of 0.07 m and effective diffusion coefficients for 3H (3HHO) and 3He of 2.4×10-5 and 1.3×10-4 m2/day, respectively. Although the 3H/3He age gradient is an excellent indicator of vertical groundwater velocities above the mid-1960s 3H peak, dispersive mixing and diffusive loss of 3He perturb the age gradient near and below the 3H peak.

Groundwater recharge to a sedimentary aquifer in the topographically closed Uley South Basin, South Australia

NASA Astrophysics Data System (ADS)

Ordens, Carlos M.; Werner, Adrian D.; Post, Vincent E. A.; Hutson, John L.; Simmons, Craig T.; Irvine, Benjamin M.

2012-02-01

The chloride mass balance (CMB) and water-table fluctuation (WTF) analysis methods were used to estimate recharge rates in the Uley South Basin, South Australia. Groundwater hydrochemistry and isotope data were used to infer the nature of recharge pathways and evapotranspiration processes. These data indicate that some combination of two plausible processes is occurring: (1) complete evaporation of rainfall occurs, and the precipitated salts are washed down and redissolved when recharge occurs, and (2) transpiration dominates over evaporation. It is surmised that sinkholes predominantly serve to by-pass the shallow soil zone and redistribute infiltration into the deeper unsaturated zone, rather than transferring rainfall directly to the water table. Chlorofluorocarbon measurements were used in approximating recharge origins to account for coastal proximity effects in the CMB method and pumping seasonality was accounted for in the WTF-based recharge estimates. Best estimates of spatially and temporally averaged recharge rates for the basin are 52-63 and 47-129 mm/year from the CMB and WTF analyses, respectively. Adaptations of both the CMB and WTF analyses to account for nuances of the system were necessary, demonstrating the need for careful application of these methods.

Numerical study on the responses of groundwater and strata to pumping and recharge in a deep confined aquifer

NASA Astrophysics Data System (ADS)

Zhang, Yang-Qing; Wang, Jian-Hua; Chen, Jin-Jian; Li, Ming-Guang

2017-05-01

Groundwater drawdown and strata settlements induced by dewatering in confined aquifers can be relieved by artificial recharge. In this study, numerical simulations of a field multi-well pumping-recharge test in a deep confined aquifer are conducted to analyze the responses of groundwater and strata to pumping and recharge. A three-dimensional numerical model is developed in a finite-difference software, which considers the fluid-mechanical interaction using the Biot consolidation theory. The predicted groundwater drawdown and ground settlements are compared to the measured data to confirm the validation of the numerical analysis of the pumping and recharge. Both numerical results and measured data indicate that the effect of recharge on controlling the groundwater drawdown and strata settlements correlates with the injection rate and well arrangements. Since the groundwater drawdown induced by pumping can be controlled by artificial recharge, soil compression can be relieved by reducing the changes of effective stress of the soils. Consequently, strata settlement induced by pumping can be relieved by artificial recharge and ground settlements can be eliminated if an appropriate injection rate and well arrangement are being determined. Moreover, the changes of the pore pressure and seepage force induced by pumping and recharge will also result in significant horizontal deformations in the strata near the recharge wells.

Determination of recharge fraction of injection water in combined abstraction-injection wells using continuous radon monitoring.

PubMed

Lee, Kil Yong; Kim, Yong-Chul; Cho, Soo Young; Kim, Seong Yun; Yoon, Yoon Yeol; Koh, Dong Chan; Ha, Kyucheol; Ko, Kyung-Seok

2016-12-01

The recharge fractions of injection water in combined abstraction-injection wells (AIW) were determined using continuous radon monitoring and radon mass balance model. The recharge system consists of three combined abstraction-injection wells, an observation well, a collection tank, an injection tank, and tubing for heating and transferring used groundwater. Groundwater was abstracted from an AIW and sprayed on the water-curtain heating facility and then the used groundwater was injected into the same AIW well by the recharge system. Radon concentrations of fresh groundwater in the AIWs and of used groundwater in the injection tank were measured continuously using a continuous radon monitoring system. Radon concentrations of fresh groundwater in the AIWs and used groundwater in the injection tank were in the ranges of 10,830-13,530 Bq/m 3 and 1500-5600 Bq/m 3 , respectively. A simple radon mass balance model was developed to estimate the recharge fraction of used groundwater in the AIWs. The recharge fraction in the 3 AIWs was in the range of 0.595-0.798. The time series recharge fraction could be obtained using the continuous radon monitoring system with a simple radon mass balance model. The results revealed that the radon mass balance model using continuous radon monitoring was effective for determining the time series recharge fractions in AIWs as well as for characterizing the recharge system. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fiabilité des structures mécaniques adaptatives: effet de la panne des actionneurs ou des capteurs sur la stabilité

NASA Astrophysics Data System (ADS)

Fall, H.; Charon, W.; Kouta, R.

2002-12-01

Ces dernières décennies, des activités significatives dans le monde étaient dirigées autour du contrôle actif. Le but de ces recherches était essentiellement d'améliorer les performances, la fiabilité et la sécurité des systèmes. Notamment dans le cas des structures soumises à des vibrations aléatoires. D'importants travaux ont été consacré à l'utilisation des “matériaux intelligents” comme capteurs et actionneurs. Cette article propose l'analyse de la fiabilité des systèmes mécaniques en étudiant les pannes des actionneurs ou des capteurs. L'effet de ces pannes sur la stabilité et la performance du système y est démontré. Les méthodologies de conception y sont rappelées. Des exemples numériques sont fournis à travers le contrôle d'un panneau sous chargement dynamique pour illustrer la méthode proposée.

Water balance-based estimation of groundwater recharge in the Lake Chad Basin

NASA Astrophysics Data System (ADS)

Babamaaji, R. A.; Lee, J.

2012-12-01

Lake Chad Basin (LCB) has experienced drastic changes of land cover and poor water management practices during the last 50 years. The successive droughts in the 1970s and 1980s resulted in the shortage of surface water and groundwater resources. This problem of drought and shortage of water has a devastating implication on the natural resources of the Basin with great consequence on food security, poverty reduction and quality of life of the inhabitants in the LCB. Therefore, understanding the change of land use and its characteristics must be a first step to find how such changes disturb the water cycle especially the groundwater in the LCB. The abundance of groundwater is affected by the climate change through the interaction with surface water, such as lakes and rivers, and vertical recharge through an infiltration process. Quantifying the impact of climate change on the groundwater resource requires not only reliable forecasting of changes in the major climatic variables, but also accurate estimation of groundwater recharge. Spatial variations in the land use/land cover, soil texture, topographic slope, and meteorological conditions should be accounted for in the recharge estimation. In this study, we employed a spatially distributed water balance model WetSpass to simulate a long-term average change of groundwater recharge in the LCB of Africa. WetSpass is a water balance-based model to estimate seasonal average spatial distribution of surface runoff, evapotranspiration, and groundwater recharge. The model is especially suitable for studying the effect of land use/land cover change on the water regime in the LCB. The present study describes the concept of the model and its application to the development of recharge map of the LCB.

Superionic glass-ceramic electrolytes for room-temperature rechargeable sodium batteries.

PubMed

Hayashi, Akitoshi; Noi, Kousuke; Sakuda, Atsushi; Tatsumisago, Masahiro

2012-05-22

Innovative rechargeable batteries that can effectively store renewable energy, such as solar and wind power, urgently need to be developed to reduce greenhouse gas emissions. All-solid-state batteries with inorganic solid electrolytes and electrodes are promising power sources for a wide range of applications because of their safety, long-cycle lives and versatile geometries. Rechargeable sodium batteries are more suitable than lithium-ion batteries, because they use abundant and ubiquitous sodium sources. Solid electrolytes are critical for realizing all-solid-state sodium batteries. Here we show that stabilization of a high-temperature phase by crystallization from the glassy state dramatically enhances the Na(+) ion conductivity. An ambient temperature conductivity of over 10(-4) S cm(-1) was obtained in a glass-ceramic electrolyte, in which a cubic Na(3)PS(4) crystal with superionic conductivity was first realized. All-solid-state sodium batteries, with a powder-compressed Na(3)PS(4) electrolyte, functioned as a rechargeable battery at room temperature.

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.

Relation of pathways and transit times of recharge water to nitrate concentrations using stable isotopes

USGS Publications Warehouse

Landon, M.K.; Delin, G.N.; Komor, S.C.; Regan, C.P.

2000-01-01

Oxygen and hydrogen stable isotope values of precipitation, irrigation water, soil water, and ground water were used with soil-moisture contents and water levels to estimate transit times and pathways of recharge water in the unsaturated zone of a sand and gravel aquifer. Nitrate-nitrogen (nitrate) concentrations in ground water were also measured to assess their relation to seasonal recharge. Stable isotope values indicated that recharge water usually had a transit time through the unsaturated zone of several weeks to months. However, wetting fronts usually moved through the unsaturated zone in hours to weeks. The much slower transit of isotopic signals than that of wetting fronts indicates that recharge was predominantly composed of older soil water that was displaced downward by more recent infiltrating water. Comparison of observed and simulated isotopic values from pure-piston flow and mixing-cell water and isotope mass balance models indicates that soil water isotopic values were usually highly mixed. Thus, movement of recharge water did not occur following a pure piston-flow displacement model but rather follows a hydrid model involving displacement of mixed older soil water with new infiltration water. An exception to this model occurred in a topographic depression, where movement of water along preferential flowpaths to the water table occurred within hours to days following spring thaw as result of depression-focused infiltration of snow melt. In an adjacent upland area, recharge of snow melt occurred one to two months later. Increases in nitrate concentrations at the water table during April-May 1993 and 1994 in a topographic lowland within a corn field were related to recharge of water that had infiltrated the previous summer and was displaced from the unsaturated zone by spring infiltration. Increases in nitrate concentrations also occurred during July-August 1994 in response to recharge of water that infiltrated during May-August 1994. These results

Groundwater origin and recharge in the hyperarid Cordillera de la Costa, Atacama Desert, northern Chile.

PubMed

Herrera, Christian; Gamboa, Carolina; Custodio, Emilio; Jordan, Teresa; Godfrey, Linda; Jódar, Jorge; Luque, José A; Vargas, Jimmy; Sáez, Alberto

2018-05-15

The Cordillera de la Costa is located along the coastline of northern Chile, in the hyperarid Atacama Desert area. Chemical and isotopic analyses of several small coastal springs and groundwater reservoirs between 22.5 °S and 25.5 °S allow understanding groundwater origin, renewal time and the probable timing of recharge. The aquifers are mostly in old volcanic rocks and alluvial deposits. All spring waters are brackish, of the sodium chloride type due to intensive concentration of precipitation due aridity and for deep groundwater to additional water-rock interaction in slowly renewed groundwater and mixing with deep seated brines. The heavy δ 18 O and δ 2 H values in spring water are explained by recharge by the arrival of moist air masses from the Pacific Ocean and the originally lighter values in the deep wells can be associated to past recharge by air masses coming from the Atlantic Ocean. Current recharge is assumed almost nil but it was significant in past wetter-than-present periods, increasing groundwater reserves, which are not yet exhausted. To explain the observed chloride content and radiocarbon ( 14 C) activity, a well-mixed (exponential) flow model has been considered for aquifer recharge. The average residence time of groundwater feeding the springs has been estimated between 1 and 2kyr, up to 5kyr and between 7 and 13kyr for deep well water, assuming that current recharge is much less than during the previous wetter period. The recharge period feeding the coastal springs could have been produced 1 to 5kyr BP, when the area was already inhabited, and recharge in the Michilla mine was produced during the 10 to 14.5kyr BP CAPE (Central Andean Pluvial Event) pluvial events of the central Andes. The approximate coincidence of turnover time with the past wet periods, as revealed by paleoclimate data, points to significant recharge during them. Copyright © 2017 Elsevier B.V. All rights reserved.

Seasonality of Groundwater Recharge in the Basin and Range Province, Western North America

NASA Astrophysics Data System (ADS)

Neff, K.; Meixner, T.; De La Cruz, L.

2014-12-01

Groundwater recharge is the primary source of aquifer replenishment, an important source of freshwater for human consumption and riparian area sustainability in semi-arid regions. It is critical to understand the current groundwater recharge regimes in groundwater basins throughout the Western U.S. and how those regimes might shift in the face of climate change, land use change and management manipulations that impact the availability and composition of groundwater resources. Watersheds in the Basin and Range Province are characterized by a variable precipitation regime of wet winters, and variable summer precipitation. The horst-graben structure of these basins lends itself to orographic and continental precipitation effects that make mountain block and mountain front recharge critical components of annual recharge. The current assumption is that the relative contributions to groundwater recharge by summer and winter precipitation vary throughout the province, with winter precipitation dominating in the northern parts of the region, and summer monsoonal precipitation playing a more significant role in the south, where the North American Monsoon extends its influence. To test this hypothesis, stable water isotope data of groundwater and precipitation from sites in Sonora, Mexico and the U.S. states of California, Nevada, Utah, Arizona, Colorado, New Mexico, and Texas were examined to characterize and compare groundwater recharge regimes throughout the region. Preliminary stable water isotope results from the southernmost Rio San Miguel Basin in Sonora, Mexico indicate that groundwater is composed of 64%±14% summer monsoon precipitation, in contrast to more northern basins where winter precipitation is the source of 79-90% of basin groundwater.

Spatially distributed groundwater recharge estimated using a water-budget model for the Island of Maui, Hawai`i, 1978–2007

USGS Publications Warehouse

Johnson, Adam G.; Engott, John A.; Bassiouni, Maoya; Rotzoll, Kolja

2014-12-14

Demand for freshwater on the Island of Maui is expected to grow. To evaluate the availability of fresh groundwater, estimates of groundwater recharge are needed. A water-budget model with a daily computation interval was developed and used to estimate the spatial distribution of recharge on Maui for average climate conditions (1978–2007 rainfall and 2010 land cover) and for drought conditions (1998–2002 rainfall and 2010 land cover). For average climate conditions, mean annual recharge for Maui is about 1,309 million gallons per day, or about 44 percent of precipitation (rainfall and fog interception). Recharge for average climate conditions is about 39 percent of total water inflow consisting of precipitation, irrigation, septic leachate, and seepage from reservoirs and cesspools. Most recharge occurs on the wet, windward slopes of Haleakalā and on the wet, uplands of West Maui Mountain. Dry, coastal areas generally have low recharge. In the dry isthmus, however, irrigated fields have greater recharge than nearby unirrigated areas. For drought conditions, mean annual recharge for Maui is about 1,010 million gallons per day, which is 23 percent less than recharge for average climate conditions. For individual aquifer-system areas used for groundwater management, recharge for drought conditions is about 8 to 51 percent less than recharge for average climate conditions. The spatial distribution of rainfall is the primary factor determining spatially distributed recharge estimates for most areas on Maui. In wet areas, recharge estimates are also sensitive to water-budget parameters that are related to runoff, fog interception, and forest-canopy evaporation. In dry areas, recharge estimates are most sensitive to irrigated crop areas and parameters related to evapotranspiration.

The feasibility of recharge rate determinations using the steady- state centrifuge method

USGS Publications Warehouse

Nimmo, J.R.; Stonestrom, David A.; Akstin, K.C.

1994-01-01

The establishment of steady unsaturated flow in a centrifuge permits accurate measurement of small values of hydraulic conductivity (K). This method can provide a recharge determination if it is applied to an unsaturated core sample from a depth at which gravity alone drives the flow. A K value determined at the in situ water content indicates the long-term average recharge rate at a point. Tests of this approach have been made at two sites. For sandy core samples a better knowledge of the matric pressure profiles is required before a recharge rate can be determined. Fine-textured cores required new developments of apparatus and procedures, especially for making centrifuge measurements with minimal compaction of the samples. -from Authors

A Wrench fault system and nappe emplacement in Southern Kenya and Northern Tanzania.- A key area for Pan-African continental collision in East Africa?

NASA Astrophysics Data System (ADS)

Bauernhofer, A.; Wallbrecher, E.; Hauzenberger, C.; Fritz, H.; Loizenbauer, J.; Hoinkes, G.; Muhongo, S.; Mathu, E.

2003-04-01

In the Voi Area of Southern Kenya, the granulite facies rocks of the Taita Hills and the Tsavo East National Park (Galana River) can be divided into three structural domains: The Galana-East unit consists of an intercalation of flat lying metapelites and marbles of continental margin origin. These metasediments can be traced further east to the Umba Steppe (Between Mombasa and Tanga). Galana-West consists of a N-S oriented wrench fault zone with vertical foliation planes and horizontal stretching lineation. Numerous shear sense indicators always show sinistral shear sense. Amphibolites of MORB affinity are involved in this wrench fault zone. To the west, this zone is bordered by calc-alkaline metatonalites of the Sagala Hills. The westernmost unit consists of the Taita Hills. They form an imbricated pile of southwestward thrusted nappe sheets containing metapelites, marbles, and ultramafics. The Taita Hills may be explained as part of an accretionary wedge. Southwestward nappe thrusting is also the prominent structure in the Pare and Usambara Mountains of Northern Tanzania. The following model may may explain these observations: The Southern Kenya -- Northern Tanzania section of the Mozambique Belt is the result of continental collision tectonics. Remnants of an island arc and of an accretionary wedge that occur at least in the Voi area may be part of a former subduction zone. An oceanic domain between an eastern passive continental margin and a western terrane, now represented by the Tanzanian granulite belt has been closed incorporating island arc and accretionary wedge material. Oblique convergence of two continental blocks is suggested from wrench tectonics. The age of convergent tectonics is 530 -- 580 Ma, dated by Sm-Nd garnet-whole rock analysis. This is interpreted as the age of peak metamorphism.

Natural groundwater recharge in an upland area of central North Dakota, U.S.A.

USGS Publications Warehouse

Rehm, B.W.; Moran, S.R.; Groenewold, G.H.

1982-01-01

The magnitude of groundwater recharge to coal aquifers in a 150-km2 area in west-central North Dakota was determined using three separate approaches: (1) the net water level rise in water-table wells; (2) calculations of the fluid flux between nested piezometers, using the Darcy equation and measured values of hydraulic conductivity and vertical gradients; and (3) evaluation of the inputs to and outputs from the coal aquifer, using a steady-state control volume approach in which the aquifer was divided into semi-rectangular cells bounded by equipotential lines and flow lines. Measurements of potential gradients and hydraulic conductivity permitted indirect determination of all components of flow into and out of the cell except the recharge input, which was determined by difference. All methods yielded consistent results on the order of 0.04-0.01 m yr.-1 These values, which represent 2-9% of the annual precipitation, are consistent with results of other studies on recharge throughout the prairies of North America. Evaluation of site hydrology and stable-isotope data indicates that recharge is restricted in both time and place. Most recharge occurs in late spring and in the fall following heavy rainfall events. During these seasons the ground is not frozen and vegetation is not transpiring large amounts of water. Some recharge may occur during very heavy localized summer storms, but it is not considered volumetrically significant. Major permanent depressions on the site are a source of significant recharge. In addition, the extensive area of ephemeral standing water bodies that result from snowmelt can produce significant amounts of infiltration over the entire site. ?? 1982.

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

2016-09-10

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.

Groundwater Recharge and Flow Processes in Taihang Mountains, a Semi-humid Region, North China

NASA Astrophysics Data System (ADS)

Sakakibara, Koichi; Tsujimura, Maki; Song, Xianfang; Zhang, Jie

2015-04-01

Groundwater flow/recharge variations in time and space are crucial for effective water management especially in semi-arid and semi-humid regions. In order to reveal comprehensive groundwater flow/recharge processes in a catchment with a large topographical relief and seasonal hydrological variations, intensive field surveys were undertaken at 4 times in different seasons (June 2011, August 2012, November 2012, February 2014) in the Wangkuai watershed, Taihang mountains, which is a main groundwater recharge area of the North China Plain. The groundwater, spring, stream water and reservoir water were taken, and inorganic solute constituents and stable isotopes of oxygen-18 and deuterium were determined on all water samples. Also, the stream flow rate and the depth of groundwater table were observed. The stable isotopic compositions and inorganic solute constituents in the groundwater are depleted and shown similar values as those of the surface water at the mountain-plain transitional area. Additionally, the groundwater in the vicinity of the Wangkuai Reservoir presents clearly higher stable isotopic compositions and lower d-excess than those of the stream water, indicating the groundwater around the reservoir is affected by evaporation same as the Wangkuai Reservoir itself. Hence, the surface water in the mountain-plain transitional area and Wangkuai Reservoir are principal groundwater recharge sources. An inversion analysis and simple mixing model were applied in the Wangkuai watershed using stable isotopes of oxygen-18 and deuterium to construct a groundwater flow model. The model shows that multi-originated groundwater flows from upstream to downstream along topography with certain mixing. In addition, the groundwater recharge occurs dominantly at the altitude from 421 m to 953 m, and the groundwater recharge rate by the Wangkuai Reservoir is estimated to be 2.4 % of the total groundwater recharge in the Wangkuai watershed. Therefore, the stream water and

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

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.

Comparison of Recharge Estimation Methods During a Wet Period in a Karst Aquifer.

PubMed

Guardiola-Albert, Carolina; Martos-Rosillo, Sergio; Pardo-Igúzquiza, Eulogio; Durán Valsero, Juan José; Pedrera, Antonio; Jiménez-Gavilán, Pablo; Liñán Baena, Cristina

2015-01-01

Management of water resources, implying their appropriate protection, calls for a sound evaluation of recharge. Such assessment is very complex in karst aquifers. Most methods are developed for application to detrital aquifers, without taking into account the extraordinary heterogeneity of porosity and permeability of karst systems. It is commonly recommended to estimate recharge using multiple methods; however, differences inherent to the diverse methods make it difficult to clarify the accuracy of each result. In this study, recharge was estimated in a karst aquifer working in a natural regime, in a Mediterranean-type climate, in the western part of the Sierra de las Nieves (southern Spain). Mediterranean climate regions are characterized by high inter-annual rainfall variability featuring long dry periods and short intense wet periods, the latter constituting the most important contribution to aquifer water input. This paper aims to identify the methods that provide the most plausible range of recharge rate during wet periods. Six methods were tested: the classical method of Thornthwaite-Mather, the Visual Balan code, the chloride balance method, and spatially distributed methods such as APLIS, a novel spatiotemporal estimation of recharge, and ZOODRM. The results help determine valid methods for application in the rest of the unit of study and in similar karst aquifers. © 2014, National Ground Water Association.

Ground Water Recharge Estimation Using Water Table Fluctuation Method And By GIS Applications

NASA Astrophysics Data System (ADS)

Vajja, V.; Bekkam, V.; Nune, R.; M. v. S, R.

2007-05-01

Quite often it has become a debating point that how much recharge is occurring to the groundwater table through rainfall on one hand and through recharge structures such as percolation ponds and checkdams on the other. In the present investigations Musi basin of Andhra Pradesh, India is selected for study during the period 2005-06. Pre-monsoon and Post-monsoon groundwater levels are collected through out the Musi basin at 89 locations covering an area11, 291.69 km2. Geology of the study area and rainfall data during the study period has been collected. The contour maps of rainfall and the change in groundwater level between Pre-monsoon and Post- monsoon have been prepared. First the change in groundwater storage is estimated for each successive strips of areas enclosed between two contours of groundwater level fluctuations. In this calculation Specific yield (Sy) values are adopted based on the local Geology. Areas between the contours are estimated through Arc GIS software package. All such storages are added to compute the total storage for the entire basin. In order to find out the percent of rainfall converted into groundwater storage as well as to find out the ground water recharge due to storageponds, a contour map of rainfall for the study area is prepared and areas between successive contours have been calculated. Based on the Geology map, Infiltration values are adopted for each successive strip of the contour area. Then the amount of water infiltrated into the ground is calculated by adjusting the infiltration values for each strip, so that the total infiltrated water for the entire basin is matched with change in Ground water storage, which is 1314.37 MCM for the upper Musi basin while it is 2827.29 MCM for entire Musi basin. With this procedure on an average 29.68 and 30.66 percent of Rainfall is converted into Groundwater recharge for Upper Musi and for entire Musi basin respectively. In the total recharge, the contribution of rainfall directly to

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.

Transmission losses, infiltration and groundwater recharge through ephemeral and intermittent streambeds: A review of applied methods

NASA Astrophysics Data System (ADS)

Shanafield, Margaret; Cook, Peter G.

2014-04-01

Aquifer recharge through ephemeral streambeds is believed to be a major source of groundwater recharge in arid areas; however, comparatively few studies quantify this streamflow recharge. This review synthesizes the available field-based aquifer recharge literature from arid regions around the world. Seven methods for quantifying ephemeral and intermittent stream infiltration and aquifer recharge are reviewed; controlled infiltration experiments, monitoring changes in water content, heat as a tracer of infiltration, reach length water balances, floodwave front tracking, groundwater mounding, and groundwater dating. The pertinent temporal and spatial scales, as well as the advantages and limitations of each method are illustrated with examples from the literature. Comparisons between the methods are used to highlight appropriate uses of each field method, with emphasis on the advantages of using multiple methods within a study in order to avoid the potential drawbacks inherent in any single method. Research needs are identified, including: quantitative uncertainty analysis, long-term data collection and analysis, understanding of the role of riparian vegetation, and reconciliation of transmission losses and infiltration estimates with actual aquifer recharge.

Hydrometeorological daily recharge assessment model (DREAM) for the Western Mountain Aquifer, Israel: Model application and effects of temporal patterns

NASA Astrophysics Data System (ADS)

Sheffer, N. A.; Dafny, E.; Gvirtzman, H.; Navon, S.; Frumkin, A.; Morin, E.

2010-05-01

Recharge is a critical issue for water management. Recharge assessment and the factors affecting recharge are of scientific and practical importance. The purpose of this study was to develop a daily recharge assessment model (DREAM) on the basis of a water balance principle with input from conventional and generally available precipitation and evaporation data and demonstrate the application of this model to recharge estimation in the Western Mountain Aquifer (WMA) in Israel. The WMA (area 13,000 km2) is a karst aquifer that supplies 360-400 Mm3 yr-1 of freshwater, which constitutes 20% of Israel's freshwater and is highly vulnerable to climate variability and change. DREAM was linked to a groundwater flow model (FEFLOW) to simulate monthly hydraulic heads and spring flows. The models were calibrated for 1987-2002 and validated for 2003-2007, yielding high agreement between calculated and measured values (R2 = 0.95; relative root-mean-square error = 4.8%; relative bias = 1.04). DREAM allows insights into the effect of intra-annual precipitation distribution factors on recharge. Although annual precipitation amount explains ˜70% of the variability in simulated recharge, analyses with DREAM indicate that the rainy season length is an important factor controlling recharge. Years with similar annual precipitation produce different recharge values as a result of temporal distribution throughout the rainy season. An experiment with a synthetic data set exhibits similar results, explaining ˜90% of the recharge variability. DREAM represents significant improvement over previous recharge estimation techniques in this region by providing near-real-time recharge estimates that can be used to predict the impact of climate variability on groundwater resources at high temporal and spatial resolution.

Developpement des betons semi autoplacants a rheologie adaptee pour des infrastructures

NASA Astrophysics Data System (ADS)

Sotomayor Cruz, Cristian Daniel

Au cours des dernières décennies, les infrastructures canadiennes et québécoises comportent plusieurs structures en béton armé présentant des problèmes de durabilité dus aux conditions climatiques sévères, à la mauvaise conception des structures, à la qualité des matériaux, aux types des bétons choisis, aux systèmes de construction ou à l'existence d'événements incontrôlables. En ce qui concerne le choix du béton pour la construction des infrastructures, une vaste gamme de béton divisée en deux principaux types peut être utilisée: le béton conventionnel vibré (BCV) et le béton autoplaçant (BAP). Dans le cas d'un BCV, la consolidation inadéquate par vibration a été un problème récurrent, occasionnant des dommages structuraux. Ceci a conduit à une réduction de la durabilité et à une augmentation du coût d'entretien et de réparation des infrastructures. Rien que l'utilisation d'un BAP a des avantages tels que l'élimination de la vibration, la réduction des coûts de main d'oeuvre et l'amélioration de la qualité des structures, néanmoins, le coût initial d'un BAP par rapport à un BCV ne permet pas encore de généraliser son utilisation dans l'industrie de la construction. Ce mémoire présente la conception d'une nouvelle gamme de béton semi-autoplaçant pour la construction des infrastructures (BSAP-I) exigeant une vibration minimale. Il s'agit de trouver un équilibre optimal entre la rhéologie et le coût initial du nouveau béton pour conférer une bonne performance structurale et économique aux structures. Le programme expérimental établi a premièrement permis d'évaluer la faisabilité d'utilisation des BSAP-I pour la mise en place des piliers d'une infrastructure de pont à Sherbrooke. En plus, l'utilisation d'un plan d'expériences a permis l'évaluation de trois paramètres de formulation sur les propriétés des mélanges de BSAP-I à l'état frais et durci. Finalement, l'évaluation de la performance des

Are isolated wetlands groundwater recharge hotspots?

NASA Astrophysics Data System (ADS)

Webb, A.; Wicks, C. M.; Brantley, S. T.; Golladay, S. W.

2017-12-01

Geographically isolated wetlands (GIWs) are a common landscape feature in the mantled karst terrain of the Dougherty Plain physiographic district in Southwestern Georgia. These wetlands support a high diversity of obligate/facultative wetland flora and fauna, including several endangered species. While the ecological value of these wetlands is well documented, the hydrologic effects of GIWs on larger watershed processes, such as water storage and aquifer recharge, are less clear. Our project seeks to understand the spatial and temporal variation in recharge across GIWs on this mantled karst landscape. In particular, our first step is to understand the role of isolated wetlands (presumed sinkholes) in delivering water into the underlying aquifer. Our hypothesis is that many GIWs are actually water-filled sinkholes and are locations of focused recharge feeding either the underlying upper Floridan aquifer or the nearby creeks. If we are correct, then these sinkholes should exhibit "drains", i.e., conduits into the limestone bedrock. Thus, the purposes of our initial study are to image the soil-limestone contact (the buried epikarstic surface) and determine if possible subsurface drains exist. Our field work was conducted at the Joseph W Jones Ecological Research Center. During the dry season, we conducted ground penetrating radar (GPR) surveys as grids and lines across a large wetland and across a field with no surface expression of a wetland or sinkhole. We used GPR (200 MHz antenna) with 1-m spacing between antenna and a ping rate of 1 ping per 40 centimeters. Our results show that the epikarstic surface exhibits a drain underneath the wetland (sinkhole) and that no similar feature was seen under the field, even though the survey grid and spacing were similar. As our project progresses, we will survey additional wetlands occurring across varying soil types to determine the spatial distribution between surface wetlands and subsurface drains.

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.

A room-temperature sodium rechargeable battery using an SO2-based nonflammable inorganic liquid catholyte

PubMed Central

Jeong, Goojin; Kim, Hansu; Sug Lee, Hyo; Han, Young-Kyu; Hwan Park, Jong; Hwan Jeon, Jae; Song, Juhye; Lee, Keonjoon; Yim, Taeeun; Jae Kim, Ki; Lee, Hyukjae; Kim, Young-Jun; Sohn, Hun-Joon

2015-01-01

Sodium rechargeable batteries can be excellent alternatives to replace lithium rechargeable ones because of the high abundance and low cost of sodium; however, there is a need to further improve the battery performance, cost-effectiveness, and safety for practical use. Here we demonstrate a new type of room-temperature and high-energy density sodium rechargeable battery using an SO2-based inorganic molten complex catholyte, which showed a discharge capacity of 153 mAh g−1 based on the mass of catholyte and carbon electrode with an operating voltage of 3 V, good rate capability and excellent cycle performance over 300 cycles. In particular, non-flammability and intrinsic self-regeneration mechanism of the inorganic liquid electrolyte presented here can accelerate the realization of commercialized Na rechargeable battery system with outstanding reliability. Given that high performance and unique properties of Na–SO2 rechargeable battery, it can be another promising candidate for next generation energy storage system. PMID:26243052

Paternité des articles et intérêts concurrents : une analyse des recommandations aux auteurs des journaux traitant de pratique pharmaceutique

PubMed Central

Courbon, Ève; Tanguay, Cynthia; Lebel, Denis; Bussières, Jean-François

2014-01-01

RÉSUMÉ Contexte : La présence d’auteurs honorifiques et fantômes ainsi que les intérêts concurrents représentent des difficultés bien documentées, liées à la publication d’articles scientifiques. Il existe des lignes directrices encadrant la rédaction et la publication de manuscrits scientifiques, notamment celles de l’International Committee of Medical Journal Editors (ICMJE). Objectifs : L’objectif principal de cette étude descriptive et transversale visait à recenser les instructions portant sur la paternité des articles et les intérêts concurrents provenant des recommandations aux auteurs des journaux traitant de pratique pharmaceutique. L’objectif secondaire visait à déterminer des mesures correctrices pour une paternité des articles plus transparente. Méthode : La recherche a débuté par l’identification des journaux traitant de pratique pharmaceutique. La consultation des instructions aux auteurs des journaux a permis ensuite de recenser les recommandations destinées à éviter les problèmes de paternité des articles et d’intérêts concurrents. Finalement, les membres de l’équipe de recherche se sont consultés afin de définir des mesures correctrices possibles à l’intention des chercheurs. Résultats : Des 232 journaux traitant de pharmacie, 33 ont été définis comme traitant de pratique pharmaceutique. Un total de 24 (73 %) journaux mentionnaient suivre la politique de l’ICMJE, 14 (42 %) demandaient aux auteurs de remplir un formulaire de déclaration d’intérêts concurrents au moment de la soumission de l’article, 17 (52 %) présentaient une définition de la qualité d’auteur et 5 (15 %) demandaient de détailler les contributions de chaque auteur. Une grille de 40 critères a été élaborée pour définir l’attribution du statut d’auteur. Conclusion : Moins de la moitié des journaux demandait aux auteurs de transmettre un formulaire de déclaration des intérêts concurrents au moment de la

Origin and recharge rates of alluvial ground waters, Eastern Desert, Egypt.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sultan, M.; Gheith, H.; Sturchio, N. C.

2002-04-12

Stable isotope and tritium analyses of shallow ground waters in the Eastern Desert of Egypt showed that the waters were derived largely by evaporation of regional precipitation and at least partly from precipitation in the past 45 y. To estimate the ground water recharge rate, we developed an integrated hydrologic model based on satellite data, geologic maps, infiltration parameters, and spatial rainfall distribution. Modeling indicated that during a severe 1994 storm, recharge through transmission loss in Wadi El-Tarfa was 21% of the precipitation volume. From archival precipitation data, we estimate that the annual recharge rate for the El-Tarfa alluvial aquifermore » is 4.7 x 10{sup 6} m{sup 3}. Implications for the use of renewable ground waters in arid areas of Egypt and in neighboring countries are clear.« less

High energy density rechargeable magnesium battery using earth-abundant and non-toxic elements

NASA Astrophysics Data System (ADS)

Orikasa, Yuki; Masese, Titus; Koyama, Yukinori; Mori, Takuya; Hattori, Masashi; Yamamoto, Kentaro; Okado, Tetsuya; Huang, Zhen-Dong; Minato, Taketoshi; Tassel, Cédric; Kim, Jungeun; Kobayashi, Yoji; Abe, Takeshi; Kageyama, Hiroshi; Uchimoto, Yoshiharu

2014-07-01

Rechargeable magnesium batteries are poised to be viable candidates for large-scale energy storage devices in smart grid communities and electric vehicles. However, the energy density of previously proposed rechargeable magnesium batteries is low, limited mainly by the cathode materials. Here, we present new design approaches for the cathode in order to realize a high-energy-density rechargeable magnesium battery system. Ion-exchanged MgFeSiO4 demonstrates a high reversible capacity exceeding 300 mAh.g-1 at a voltage of approximately 2.4 V vs. Mg. Further, the electronic and crystal structure of ion-exchanged MgFeSiO4 changes during the charging and discharging processes, which demonstrates the (de)insertion of magnesium in the host structure. The combination of ion-exchanged MgFeSiO4 with a magnesium bis(trifluoromethylsulfonyl)imide-triglyme electrolyte system proposed in this work provides a low-cost and practical rechargeable magnesium battery with high energy density, free from corrosion and safety problems.

Optimization of an artificial-recharge-pumping system for water supply in the Maghaway Valley, Cebu, Philippines

NASA Astrophysics Data System (ADS)

Kawo, Nafyad Serre; Zhou, Yangxiao; Magalso, Ronnell; Salvacion, Lasaro

2018-05-01

A coupled simulation-optimization approach to optimize an artificial-recharge-pumping system for the water supply in the Maghaway Valley, Cebu, Philippines, is presented. The objective is to maximize the total pumping rate through a system of artificial recharge and pumping while meeting constraints such as groundwater-level drawdown and bounds on pumping rates at each well. The simulation models were coupled with groundwater management optimization to maximize production rates. Under steady-state natural conditions, the significant inflow to the aquifer comes from river leakage, whereas the natural discharge is mainly the subsurface outflow to the downstream area. Results from the steady artificial-recharge-pumping simulation model show that artificial recharge is about 20,587 m3/day and accounts for 77% of total inflow. Under transient artificial-recharge-pumping conditions, artificial recharge varies between 14,000 and 20,000 m3/day depending on the wet and dry seasons, respectively. The steady-state optimisation results show that the total optimal abstraction rate is 37,545 m3/day and artificial recharge is increased to 29,313 m3/day. The transient optimization results show that the average total optimal pumping rate is 36,969 m3/day for the current weir height. The transient optimization results for an increase in weir height by 1 and 2 m show that the average total optimal pumping rates are increased to 38,768 and 40,463 m3/day, respectively. It is concluded that the increase in the height of the weir can significantly increase the artificial recharge rate and production rate in Maghaway Valley.

Identifying areas of basin-floor recharge in the Trans-Pecos region and the link to vegetation

USGS Publications Warehouse

Walvoord, Michelle Ann; Phillips, Fred M.

2004-01-01

Comparative water potential and chloride profiles (∼10 m deep) collected from four vegetation communities in the Trans-Pecos region of the Chihuahuan Desert were assessed to evaluate the potential for using vegetation patterns as a means of efficiently improving large-scale estimates of basin-floor recharge in semiarid and arid regions. Analytical solutions and multiphase flow and transport modeling constrained flux histories and current fluxes across the water table at each site. Chloride bulge profiles containing ∼12–15 kyr of atmospheric deposition and long-term drying water potential profiles typified most desertscrub and grassland sites. In contrast, evidence of episodic sub-root zone percolation and chloride profiles containing <250 yr of atmospheric deposition characterized the woodland site. The results suggested that the desertscrub and grassland areas support small upward fluxes across the water table (nonrecharge), whereas the woodland site supports significant downward fluxes across the water table (recharge). A nonrecharge–recharge transition was identified to be collocated with a grassland–woodland ecotone. The establishment of vegetation–recharge relationships such as this will improve estimates of basin-scale recharge by identifying regions where no recharge is expected and regions where recharge is expected and point measurements should be concentrated. An approach integrating remotely sensed spatial distributions of vegetation and indicator relationships to recharge is both timely and warranted, although several caveats, as revealed in this study, should be noted. For example, the relative importance and distribution of vertical conduits that permit percolation to the water table merits future investigation.

Relation of streams, lakes, and wetlands to groundwater flow systems

NASA Astrophysics Data System (ADS)

Winter, Thomas C.

Surface-water bodies are integral parts of groundwater flow systems. Groundwater interacts with surface water in nearly all landscapes, ranging from small streams, lakes, and wetlands in headwater areas to major river valleys and seacoasts. Although it generally is assumed that topographically high areas are groundwater recharge areas and topographically low areas are groundwater discharge areas, this is true primarily for regional flow systems. The superposition of local flow systems associated with surface-water bodies on this regional framework results in complex interactions between groundwater and surface water in all landscapes, regardless of regional topographic position. Hydrologic processes associated with the surface-water bodies themselves, such as seasonally high surface-water levels and evaporation and transpiration of groundwater from around the perimeter of surface-water bodies, are a major cause of the complex and seasonally dynamic groundwater flow fields associated with surface water. These processes have been documented at research sites in glacial, dune, coastal, mantled karst, and riverine terrains. Résumé Les eaux de surface sont parties intégrantes des systèmes aquifères. Les eaux souterraines interagissent avec les eaux de surface dans presque tous les types d'environnements, depuis les petits ruisseaux, les lacs et les zones humides jusqu'aux bassins versants des vallées des grands fleuves et aux lignes de côte. Il est en général admis que les zones topographiquement hautes sont des lieux de recharge des aquifères et les zones basses des lieux de décharge, ce qui est le cas des grands systèmes aquifères régionaux. La superposition de systèmes locaux, associés à des eaux de surface, à l'organisation régionale d'écoulements souterrains résulte d'interactions complexes entre les eaux souterraines et les eaux de surface dans tous les environnements, quelle que soit la situation topographique régionale. Les processus

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

PubMed Central

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. PMID:27626422

Measuring and computing natural ground-water recharge at sites in south-central Kansas

USGS Publications Warehouse

Sophocleous, M.A.; Perry, C.A.

1987-01-01

To measure the natural groundwater recharge process, two sites in south-central Kansas were instrumented with sensors and data microloggers. The atmospheric-boundary layer and the unsaturated and saturated soil zones were monitored as a single regime. Direct observations also were used to evaluate the measurements. Atmospheric sensors included an anemometer, a tipping-bucket rain gage, an air-temperature thermistor, a relative-humidity probe, a net radiometer, and a barometric-pressure transducer. Sensors in the unsaturated zone consisted of soil-temperature thermocouples, tensiometers coupled with pressure transducers and dial gages, gypsum blocks, and a neutron-moisture probe. The saturated-zone sensors consisted of a water-level pressure transducer, a conventional float gage connected to a variable potentiometer, soil thermocouples, and a number of multiple-depth piezometers. Evaluation of the operation of these sensors and recorders indicates that certain types of equipment, such as pressure transducers, are very sensitive to environmental conditions. A number of suggestions aimed at improving instrumentation of recharge investigations are outlined. Precipitation and evapotranspiration data, taken together with soil moisture profiles and storage changes, water fluxes in the unsaturated zone and hydraulic gradients in the saturated zone at various depths, soil temperature, water table hydrographs, and water level changes in nearby wells, describe the recharge process. Although the two instrumented sites are located in sand-dune environments in area characterized by a shallow water table and a sub-humid continental climate, a significant difference was observed in the estimated total recharge. The estimates ranged from less than 2.5 mm at the Zenith site to approximately 154 mm at the Burrton site from February to June 1983. The principal reasons that the Burrton site had more recharge than the Zenith site were more precipitation, less evapotranspiration, and a

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.

Evaluation of recharge to the Skunk Creek Aquifer from a constructed wetland near Lyons, South Dakota

USGS Publications Warehouse

Thompson, Ryan F.

2002-01-01

A wetland was constructed in the Skunk Creek flood plain near Lyons in southeast South Dakota to mitigate for wetland areas that were filled during construction of a municipal golf course for the city of Sioux Falls. A water-rights permit was obtained to allow the city to pump water from Skunk Creek into the wetland during times when the wetland would be dry. The amount of water seeping through the wetland and recharging the underlying Skunk Creek aquifer was not known. The U.S. Geological Survey, in cooperation with the city of Sioux Falls, conducted a study during 1997-2000 to evaluate recharge to the Skunk Creek aquifer from the constructed wetland. Three methods were used to estimate recharge from the wetland to the aquifer: (1) analysis of the rate of water-level decline during periods of no inflow; (2) flow-net analysis; and (3) analysis of the hydrologic budget. The hydrologic budget also was used to evaluate the efficiency of recharge from the wetland to the aquifer. Recharge rates estimated by analysis of shut-off events ranged from 0.21 to 0.82 foot per day, but these estimates may be influenced by possible errors in volume calculations. Recharge rates determined by flow-net analysis were calculated using selected values of hydraulic conductivity and ranged from 566,000 gallons per day using a hydraulic conductivity of 0.5 foot per day to 1,684,000 gallons per day using a hydraulic conductivity of 1.0 foot per day. Recharge rates from the hydrologic budget varied from 0.74 to 0.85 foot per day, and averaged 0.79 foot per day. The amount of water lost to evapotranspiration at the study wetland is very small compared to the amount of water seeping from the wetland into the aquifer. Based on the hydrologic budget, the average recharge efficiency was estimated as 97.9 percent, which indicates that recharging the Skunk Creek aquifer by pumping water into the study wetland is highly efficient. Because the Skunk Creek aquifer is composed of sand and gravel, the

Novel Nanocomposite Materials for Advanced Li-Ion Rechargeable Batteries

PubMed Central

Cai, Chuan; Wang, Ying

2009-01-01

Nanostructured materials lie at the heart of fundamental advances in efficient energy storage and/or conversion, in which surface processes and transport kinetics play determining roles. Nanocomposite materials will have a further enhancement in properties compared to their constituent phases. This Review describes some recent developments of nanocomposite materials for high-performance Li-ion rechargeable batteries, including carbon-oxide nanocomposites, polymer-oxide nanocomposites, metal-oxide nanocomposites, and silicon-based nanocomposites, etc. The major goal of this Review is to highlight some new progress in using these nanocomposite materials as electrodes to develop Li-ion rechargeable batteries with high energy density, high rate capability, and excellent cycling stability.

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.

Estimating the recharge properties of the deep ocean using noble gases and helium isotopes

NASA Astrophysics Data System (ADS)

Loose, Brice; Jenkins, William J.; Moriarty, Roisin; Brown, Peter; Jullion, Loic; Naveira Garabato, Alberto C.; Torres Valdes, Sinhue; Hoppema, Mario; Ballentine, Chris; Meredith, Michael P.

2016-08-01

The distribution of noble gases and helium isotopes in the dense shelf waters of Antarctica reflects the boundary conditions near the ocean surface: air-sea exchange, sea ice formation, and subsurface ice melt. We use a nonlinear least squares solution to determine the value of the recharge temperature and salinity, as well as the excess air injection and glacial meltwater content throughout the water column and in the precursor to Antarctic Bottom Water. The noble gas-derived recharge temperature and salinity in the Weddell Gyre are -1.95°C and 34.95 psu near 5500 m; these cold, salty recharge values are a result of surface cooling as well as brine rejection during sea ice formation in Antarctic polynyas. In comparison, the global value for deep water recharge temperature is -0.44°C at 5500 m, which is 1.5°C warmer than the southern hemisphere deep water recharge temperature, reflecting a distinct contribution from the north Atlantic. The contrast between northern and southern hemisphere recharge properties highlights the impact of sea ice formation on setting the gas properties in southern sourced deep water. Below 1000 m, glacial meltwater averages 3.5‰ by volume and represents greater than 50% of the excess neon and argon found in the water column. These results indicate glacial melt has a nonnegligible impact on the atmospheric gas content of Antarctic Bottom Water.

Culm Age and Rhizome Affects Night-Time Water Recharge in the Bamboo Phyllostachys pubescens

PubMed Central

Zhao, Xiuhua; Zhao, Ping; Zhang, Zhenzhen; Zhu, Liwei; Hu, Yanting; Ouyang, Lei; Ni, Guangyan; Ye, Qing

2017-01-01

Bamboo species—the only herbaceous trees—have unique structural and physiological characteristics that differ from those of other tree taxa. However, the role of night-time water use in bamboo is poorly understood and has rarely been investigated. We studied the day- and night-time sap flow response to culm age and rhizome structure in three age levels (juvenile, mature, and senescent) of Phyllostachys pubescens growing in the Nankun Mountain Natural Reserve, South China. We found that sap flow density and whole-tree hydraulic conductance decreased with culm age. After cutting of rhizome, the day-time sap flow and night-time water recharge decreased obviously. In addition, night-time water recharge accounted for the largest proportion (up to 30%) of total daily transpiration in normal senescent bamboos. Therefore, our study indicates that the connected rhizome system and night-time water recharge played a significant role in water compensation during the day and at night in bamboos. Night-time water recharge is especially critical to senescent bamboos, given their weaker transpiration due to the lower whole-tree hydraulic conductance, and consequently, they are more dependent on night-time water recharge for fulfilling their whole-day water consumption needs. PMID:29176989

Culm Age and Rhizome Affects Night-Time Water Recharge in the Bamboo Phyllostachys pubescens.

PubMed

Zhao, Xiuhua; Zhao, Ping; Zhang, Zhenzhen; Zhu, Liwei; Hu, Yanting; Ouyang, Lei; Ni, Guangyan; Ye, Qing

2017-01-01

Bamboo species-the only herbaceous trees-have unique structural and physiological characteristics that differ from those of other tree taxa. However, the role of night-time water use in bamboo is poorly understood and has rarely been investigated. We studied the day- and night-time sap flow response to culm age and rhizome structure in three age levels (juvenile, mature, and senescent) of Phyllostachys pubescens growing in the Nankun Mountain Natural Reserve, South China. We found that sap flow density and whole-tree hydraulic conductance decreased with culm age. After cutting of rhizome, the day-time sap flow and night-time water recharge decreased obviously. In addition, night-time water recharge accounted for the largest proportion (up to 30%) of total daily transpiration in normal senescent bamboos. Therefore, our study indicates that the connected rhizome system and night-time water recharge played a significant role in water compensation during the day and at night in bamboos. Night-time water recharge is especially critical to senescent bamboos, given their weaker transpiration due to the lower whole-tree hydraulic conductance, and consequently, they are more dependent on night-time water recharge for fulfilling their whole-day water consumption needs.

Vulnerability of ground water to contamination, Edwards Aquifer recharge zone, Bexar County, Texas, 1998

USGS Publications Warehouse

Clark, Allan K.

2000-01-01

The Edwards aquifer, one of the most productive carbonate-rock aquifers in the Nation, is composed of the Kainer and Person Formations of the Edwards Group plus the overlying Georgetown Formation. Most recharge to the Edwards aquifer results from the percolation of streamflow loss and the infiltration of precipitation through porous parts of the recharge zone. Residential and commercial development is increasing, particularly in Bexar County in south-central Texas, atop the densely fractured and steeply faulted recharge zone. The increasing development has increased the vulnerability of ground water to contamination by spillage or leakage of waste materials, particularly fluids associated with urban runoff and (or) septic-tank leachate. This report describes a method of assessing the vulnerability of ground water to contamination in the Edwards aquifer recharge zone. The method is based on ratings of five natural features of the area: (1) hydraulic properties of outcropping hydrogeologic units; (2) presence or absence of faults; (3) presence or absence of caves and (or) sinkholes; (4) slope of land surface; and (5) permeability of soil. The sum of the ratings for the five natural features was used to develop a map showing the recharge zone's vulnerability to ground-water contamination.

Determining the groundwater potential recharge zone and karst springs catchment area: Saldoran region, western Iran

NASA Astrophysics Data System (ADS)

Karami, Gholam Hossein; Bagheri, Rahim; Rahimi, Fahimeh

2016-12-01

Assessing the groundwater recharge potential zone and differentiation of the spring catchment area are extremely important to effective management of groundwater systems and protection of water quality. The study area is located in the Saldoran karstic region, western Iran. It is characterized by a high rate of precipitation and recharge via highly permeable fractured karstic formations. Pire-Ghar, Sarabe-Babaheydar and Baghe-rostam are three major karstic springs which drain the Saldoran anticline. The mean discharge rate and electrical conductivity values for these springs were 3, 1.9 and 0.98 m3/s, and 475, 438 and 347 μS/cm, respectively. Geology, hydrogeology and geographical information system (GIS) methods were used to define the catchment areas of the major karstic springs and to map recharge zones in the Saldoran anticline. Seven major influencing factors on groundwater recharge rates (lithology, slope value and aspect, drainage, precipitation, fracture density and karstic domains) were integrated using GIS. Geology maps and field verification were used to determine the weights of factors. The final map was produced to reveal major zones of recharge potential. More than 80 % of the study area is terrain that has a recharge rate of 55-70 % (average 63 %). Evaluating the water budget of Saldoran Mountain showed that the total volume of karst water emerging from the Saldoran karst springs is equal to the total annual recharge on the anticline. Therefore, based on the geological and hydrogeological investigations, the catchment area of the mentioned karst springs includes the whole Saldoran anticline.

Caracterisation des melanges developpes pour le moulage basse pression des poudres metalliques (LPIM) =

NASA Astrophysics Data System (ADS)

Fareh, Fouad

Le moulage par injection basse pression des poudres metalliques est une technique de fabrication qui permet de fabriquer des pieces possedant la complexite des pieces coulees mais avec les proprietes mecaniques des pieces corroyees. Cependant, l'optimisation des etapes de deliantage et de frittage a ete jusqu'a maintenant effectuee a l'aide de melange pour lesquels la moulabilite optimale n'a pas encore ete demontree. Ainsi, la comprehension des proprietes rheologiques et de la segregation des melanges est tres limitee et cela presente le point faible du processus de LPIM. L'objectif de ce projet de recherche etait de caracteriser l'influence des liants sur le comportement rheologique des melanges en mesurant la viscosite et la segregation des melanges faible viscosite utilises dans le procede LPIM. Afin d'atteindre cet objectif, des essais rheologiques et thermogravimetriques ont ete conduits sur 12 melanges. Ces melanges ont ete prepares a base de poudre d'Inconel 718 de forme spherique (chargement solide constant a 60%) et de cires, d'agents surfactants ou epaississants. Les essais rheologiques ont ete utilises entre autre pour calculer l'indice d'injectabilite ?STV des melanges, tandis que les essais thermogravimetriques ont permis d'evaluer precisement la segregation des poudres dans les melanges. Il a ete demontre que les trois (3) melanges contenant de la cire de paraffine et de l'acide stearique presentent des indices alpha STV plus eleves qui sont avantageux pour le moulage par injection des poudres metalliques (MIM), mais segregent beaucoup trop pour que la piece fabriquee produise de bonnes caracteristiques mecaniques. A l'oppose, le melange contenant de la cire de paraffine et de l'ethylene-vinyle acetate ainsi que le melange contenant seulement de la cire de carnauba segregent peu voire pas du tout, mais possedent de tres faibles indices alphaSTV : ils sont donc difficilement injectables. Le meilleur compromis semble donc etre les melanges contenant de

Ground-water recharge to the regolith-fractured crystalline rock aquifer system, Orange County, North Carolina

USGS Publications Warehouse

Daniel, C. C.

1996-01-01

Quantitative information concerning recharge rates to aquifers and ground water in storage is needed to manage the development of ground-water resources. The amount of ground water available from the regolith-fractured crystalline rock aquifer system in Orange County, North Carolina, is largely unknown. If historical patterns seen throughout the Piedmont continue into the future, the number of ground-water users in the county can be expected to increase. In order to determine the maximum population that can be supplied by ground water, planners and managers of suburban development must know the amount of ground water that can be withdrawn without exceeding recharge and(or) overdrafting water in long-term storage. Results of the study described in this report help provide this information. Estimates of seasonal and long-term recharge rates were estimated for 12 selected drainage basins and subbasins using streamflow data and an analytical technique known as hydrograph separation. Methods for determining the quality of ground water in storage also are described. Orange County covers approximately 401 square miles in the eastern part of the Piedmont Province. The population of the county in 1990 was about 93,850; approximately 41 percent of the population depends on ground water as a source of potable supplies. Ground water is obtained from wells tapping the regolith-fractured crystalline rock aquifer system that underlies most of the county. Ground water also is obtained from Triassic age sedimentary rocks that occur in a small area in southeastern Orange County. Under natural conditions, recharge to the county's ground-water system is derived from the infiltration of precipitation. Ground-water recharge from precipitation cannot be measured directly; however, an estimate of the amount of precipitation that infiltrates into the ground and ultimately reaches the streams of the region can be determined by the technique of hydrograph separation. Data from 17 gaging

Assessment of Areal Recharge to the Spokane Valley-Rathdrum Prairie Aquifer, Spokane County, Washington, and Bonner and Kootenai Counties, Idaho

USGS Publications Warehouse

Bartolino, James R.

2007-01-01

A numerical flow model of the Spokane Valley-Rathdrum Prairie aquifer currently (2007) being developed requires the input of values for areally-distributed recharge, a parameter that is often the most uncertain component of water budgets and ground-water flow models because it is virtually impossible to measure over large areas. Data from six active weather stations in and near the study area were used in four recharge-calculation techniques or approaches; the Langbein method, in which recharge is estimated on the basis of empirical data from other basins; a method developed by the U.S. Department of Agriculture (USDA), in which crop consumptive use and effective precipitation are first calculated and then subtracted from actual precipitation to yield an estimate of recharge; an approach developed as part of the Eastern Snake Plain Aquifer Model (ESPAM) Enhancement Project in which recharge is calculated on the basis of precipitation-recharge relations from other basins; and an approach in which reference evapotranspiration is calculated by the Food and Agriculture Organization (FAO) Penman-Monteith equation, crop consumptive use is determined (using a single or dual coefficient approach), and recharge is calculated. Annual recharge calculated by the Langbein method for the six weather stations was 4 percent of annual mean precipitation, yielding the lowest values of the methods discussed in this report, however, the Langbein method can be only applied to annual time periods. Mean monthly recharge calculated by the USDA method ranged from 53 to 73 percent of mean monthly precipitation. Mean annual recharge ranged from 64 to 69 percent of mean annual precipitation. Separate mean monthly recharge calculations were made with the ESPAM method using initial input parameters to represent thin-soil, thick-soil, and lava-rock conditions. The lava-rock parameters yielded the highest recharge values and the thick-soil parameters the lowest. For thin-soil parameters

Rechargeable Lithium/Polymer Cathode Batteries

DTIC Science & Technology

1989-06-15

rechargeable lithium batteries. PPy films prepared with P-anion and/or t.substrate precoated with niLrile butadieve rubber ( NBR ) were excellent cathode...in the polymerization and with NBR (nitrile butadiene rubber )-guided- solution gives beautiful reversibility of anion grown method(4,5). Since an...Tokyo, Japan 169 density of 2.5 mA cm- 2 (3). Moreover, PPy prepa- ration through the host polymer of NBR insulat- SCorrosion Research Center, ing film

Mitigating agricultural impacts on groundwater using distributed managed aquifer recharge ponds

NASA Astrophysics Data System (ADS)

Schmidt, C. M.; Russo, T. A.; Fisher, A. T.; Racz, A. J.; Wheat, C. G.; Los Huertos, M.; Lockwood, B. S.

2010-12-01

Groundwater is likely to become increasingly important for irrigated agriculture due to anticipated changes to the hydrologic cycle associated with climate change. Protecting the quantity and quality of subsurface water supplies will require flexible management strategies that can enhance groundwater recharge. We present results from a study of managed aquifer recharge (MAR) in central coastal California, and propose the use of distributed, small-scale (1-5 ha) MAR systems to improve the quantity and quality of recharge in agricultural basins. Our field site is located in a basin where the primary use of groundwater is irrigation for agriculture, and groundwater resources are increasingly threatened by seawater intrusion and nutrient contamination from fertilizer application. The MAR system we are monitoring is supplied by stormwater and irrigation runoff of variable quality, which is diverted from a wetland during periods of high flow. This MAR system delivers approximately 1x106 m3 of recharge annually to the underlying aquifer, a portion of which is recovered and distributed to growers during the dry season. Our sampling and measurements (at high spatial and temporal resolution) show that a significant percentage of the nitrogen load added during MAR operation is eliminated from recharge during shallow infiltration (~30% to 60%, ~40 kg NO3-N/d). Isotopic analyses of the residual nitrate indicate that a significant fraction of the nitrate load reduction is attributable to denitrification. When normalized to infiltration pond area, this system achieves a mean load reduction of 7 kg NO3-N/d/ha, which compares favorably with the nitrogen load reduction efficiency achieved by treatment wetlands receiving agricultural runoff. Much of the reduction in nitrogen load occurs during periods of rapid infiltration (0.2 to 2.0 m/day), as demonstrated with point measurements of infiltration rate collocated with fluid samples. These results suggest that developing a network of

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.

La participation des enfants et des adolescents à la boxe

PubMed Central

Purcell, Laura K; LeBlanc, Claire MA

2012-01-01

RÉSUMÉ Des milliers de garçons et de filles de moins de 19 ans font de la boxe en Amérique du Nord. Même si la boxe comporte des avantages pour ceux qui y participent, y compris l’exercice, l’autodiscipline et la confiance en soi, le sport lui-même favorise et récompense des coups délibérés à la tête et au visage. Les personnes qui font de la boxe risquent de subir des blessures à la tête, au visage et au cou, y compris des traumatismes neurologiques chroniques et même fatals. Les commotions cérébrales sont l’une des principales blessures causées par la boxe. En raison du risque de blessures crâniennes et faciales, la Société canadienne de pédiatrie et l’American Academy of Pediatrics s’opposent vigoureusement à la boxe comme activité sportive pour les enfants et les adolescents. Ces organismes recommandent que les médecins s’élèvent contre la boxe auprès des jeunes et les encouragent à participer à d’autres activités dans lesquelles les coups intentionnels à la tête ne constituent pas un élément essentiel du sport.

High efficiency iron electrode and additives for use in rechargeable iron-based batteries

DOEpatents

Narayan, Sri R.; Prakash, G. K. Surya; Aniszfeld, Robert; Manohar, Aswin; Malkhandi, Souradip; Yang, Bo

2017-02-21

An iron electrode and a method of manufacturing an iron electrode for use in an iron-based rechargeable battery are disclosed. In one embodiment, the iron electrode includes carbonyl iron powder and one of a metal sulfide additive or metal oxide additive selected from the group of metals consisting of bismuth, lead, mercury, indium, gallium, and tin for suppressing hydrogen evolution at the iron electrode during charging of the iron-based rechargeable battery. An iron-air rechargeable battery including an iron electrode comprising carbonyl iron is also disclosed, as is an iron-air battery wherein at least one of the iron electrode and the electrolyte includes an organosulfur additive.

Estimating groundwater recharge in Hebei Plain, China under varying land use practices using tritium and bromide tracers

NASA Astrophysics Data System (ADS)

Wang, Bingguo; Jin, Menggui; Nimmo, John R.; Yang, Lei; Wang, Wenfeng

2008-07-01

SummaryTritium and bromide were used as applied tracers to determine groundwater recharge in Hebei Plain, North China, to evaluate the impacts of different soil types, land use, irrigation, and crop cultivation practice on recharge. Additional objectives were to evaluate temporal variability of recharge and the effect on results of the particular tracer used. Thirty-nine profiles at representative locations were chosen for investigation. Average recharge rates and recharge coefficient determined by tritium and bromide tracing for different sites were 0.00-1.05 mm/d and 0.0-42.5%, respectively. The results showed relative recharge rates for the following paired influences (items within each pair are listed with the influence producing greater recharge first): flood-irrigated cropland and non-irrigated non-cultivation land, flood irrigation (0.42-0.58 mm/d) and sprinkling irrigation (0.17-0.23 mm/d), no stalk mulch (0.56-0.80 mm/d) and stalk mulch (0.44-0.60 mm/d), vegetable (e.g. Chinese cabbage and garlic, 0.70 mm/d) and wheat-maize (0.38 mm/d), peanut (0.51 mm/d) and peach (0.43 mm/d). The results also showed greater recharge for the first year of tracer travel than for the second. Because total precipitation and irrigation were greater in the first year than in the second, this may reflect temporal variability of recharge. The method may not be applicable where the water table is shallow (less than 3 m). A comparison of the near-ideal tritium tracer with the more common but less ideal bromide showed that bromide moved approximately 23% faster than tritiated water, perhaps because of anion exclusion.

Estimating groundwater recharge in Hebei Plain, China under varying land use practices using tritium and bromide tracers

USGS Publications Warehouse

Wang, B.; Jin, M.; Nimmo, J.R.; Yang, L.; Wang, W.

2008-01-01

Tritium and bromide were used as applied tracers to determine groundwater recharge in Hebei Plain, North China, to evaluate the impacts of different soil types, land use, irrigation, and crop cultivation practice on recharge. Additional objectives were to evaluate temporal variability of recharge and the effect on results of the particular tracer used. Thirty-nine profiles at representative locations were chosen for investigation. Average recharge rates and recharge coefficient determined by tritium and bromide tracing for different sites were 0.00-1.05 mm/d and 0.0-42.5%, respectively. The results showed relative recharge rates for the following paired influences (items within each pair are listed with the influence producing greater recharge first): flood-irrigated cropland and non-irrigated non-cultivation land, flood irrigation (0.42-0.58 mm/d) and sprinkling irrigation (0.17-0.23 mm/d), no stalk mulch (0.56-0.80 mm/d) and stalk mulch (0.44-0.60 mm/d), vegetable (e.g. Chinese cabbage and garlic, 0.70 mm/d) and wheat-maize (0.38 mm/d), peanut (0.51 mm/d) and peach (0.43 mm/d). The results also showed greater recharge for the first year of tracer travel than for the second. Because total precipitation and irrigation were greater in the first year than in the second, this may reflect temporal variability of recharge. The method may not be applicable where the water table is shallow (less than 3 m). A comparison of the near-ideal tritium tracer with the more common but less ideal bromide showed that bromide moved approximately 23% faster than tritiated water, perhaps because of anion exclusion. ?? 2008 Elsevier B.V.

Climate change impacts on groundwater recharge- uncertainty, shortcomings, and the way forward?

NASA Astrophysics Data System (ADS)

Holman, I. P.

2006-06-01

An integrated approach to assessing the regional impacts of climate and socio-economic change on groundwater recharge is described from East Anglia, UK. Many factors affect future groundwater recharge including changed precipitation and temperature regimes, coastal flooding, urbanization, woodland establishment, and changes in cropping and rotations. Important sources of uncertainty and shortcomings in recharge estimation are discussed in the light of the results. The uncertainty in, and importance of, socio-economic scenarios in exploring the consequences of unknown future changes are highlighted. Changes to soil properties are occurring over a range of time scales, such that the soils of the future may not have the same infiltration properties as existing soils. The potential implications involved in assuming unchanging soil properties are described. 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.

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...

Predicting water quality changes from artificial recharge sources to nearby wellfields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moran, J.E.

1998-01-23

Isotope tracer technologies have proven to be powerful tools for addressing questions related to surface water-ground water interactions. The Alameda County Water District artificially recharges tens of thousands of acre-ft of water annually, delivered from Alameda Creek in order to augment dwindling ground water supplies, and to maintain a barrier to seawater intrusion. The authors are using a suite of isotope tracers to track water movement, source characteristics and accompanying water quality changes from ACWD recharge facilities to nearby wells. The data gathered during the three year project will allow quantification of dilution by ambient basin ground water, subsurface travelmore » times, and several key water quality parameters, including degree of degradation of organic compounds, the fate of trace metals during recharge and subsurface transport, and sources and transport of major ions (salts). Reconnaissance work was carried out on naturally occurring isotopes in order to better understand the hydrogeology of the ground water basin. The basin is dissected by the Hayward Fault, and geologic conditions vary greatly on either side of the fault. Stable isotopes of oxygen, carbon, helium and other noble gases, along with radiocarbon and tritium were measured on water samples from production and monitoring wells. The goal of the reconnaissance work was to age date the water at various depths and distances from the recharge ponds, to examine the chemical evolution of the water with age, and to examine the water for source-related variations in isotope composition. Ground water ages were calculated by the tritium-helium method for three production wells in the Peralta-Tyson wellfield (in the Above Hayward Fault sub-basin), and for a monitoring well positioned between the recharge facilities and production wells, screened at three discreet intervals.« less

Groundwater recharge in the tropics: a pan-African analysis of observations

NASA Astrophysics Data System (ADS)

Taylor, R. G.

2015-12-01

Groundwater is a vital source of freshwater in sub-Saharan Africa where rainfall and river discharge are unreliable and per-capita reservoir storage is among the lowest in the world. Groundwater is widely considered a distributed, low-cost and climate-resilient option to meet rapidly growing freshwater demand and alleviate endemic poverty by expanding access to safe water and improving food security through irrigation. Recent research indicates that groundwater storage in Africa is about 100 times greater than annual river discharge yet major uncertainties remain in the magnitude and nature of replenishment through recharge as well as the impacts of land-use and climate change. Here, we present newly compiled, multi-decadal observations of groundwater levels from 5 countries (Benin, Burkina Faso, Niger, Tanzania, Uganda) and paired measurements of stable isotope ratios of O and H in precipitation and groundwater at 11 locations. These data reveal both a distinct bias in groundwater recharge to intensive rainfall and rapid recharge pathways (e.g. focused, macropore flow) that are inconsistent with conventional recharge models assuming pore-matrix flow defined by the Darcy-Richards equation. Further the records highlight the substantial influence of land-use change (e.g. conversion of natural, perennial cover to croplands) on groundwater recharge. The compiled observations also provide, for the first time, a pan-African baseline to evaluate the performance of large-scale hydrological models and Land-Surface Models incorporating groundwater in this region. Our results suggest that the intensification of precipitation brought about by global warming favours groundwater replenishment in sub-Saharan Africa. As such, groundwater may prove to be a climate-resilient source of freshwater in the tropics, enabling adaptive strategies such as groundwater-fed irrigation and sustaining domestic and industrial water supplies.

Membrane fluidization by alcohols inhibits DesK-DesR signalling in Bacillus subtilis.

PubMed

Vaňousová, Kateřina; Beranová, Jana; Fišer, Radovan; Jemioła-Rzemińska, Malgorzata; Matyska Lišková, Petra; Cybulski, Larisa; Strzałka, Kazimierz; Konopásek, Ivo

2018-03-01

After cold shock, the Bacillus subtilis desaturase Des introduces double bonds into the fatty acids of existing membrane phospholipids. The synthesis of Des is regulated exclusively by the two-component system DesK/DesR; DesK serves as a sensor of the state of the membrane and triggers Des synthesis after a decrease in membrane fluidity. The aim of our work is to investigate the biophysical changes in the membrane that are able to affect the DesK signalling state. Using linear alcohols (ethanol, propanol, butanol, hexanol, octanol) and benzyl alcohol, we were able to suppress Des synthesis after a temperature downshift. The changes in the biophysical properties of the membrane caused by alcohol addition were followed using membrane fluorescent probes and differential scanning calorimetry. We found that the membrane fluidization induced by alcohols was reflected in an increased hydration at the lipid-water interface. This is associated with a decrease in DesK activity. The addition of alcohol mimics a temperature increase, which can be measured isothermically by fluorescence anisotropy. The effect of alcohols on the membrane periphery is in line with the concept of the mechanism by which two hydrophilic motifs located at opposite ends of the transmembrane region of DesK, which work as a molecular caliper, sense temperature-dependent variations in membrane properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Identifying long term empirical relationships between storm characteristics and episodic groundwater recharge

USGS Publications Warehouse

Tashie, Arik; Mirus, Benjamin B.; Pavelsky, Tamlin

2016-01-01

Shallow aquifers are an important source of water resources and provide base flow to streams; yet actual rates of groundwater recharge are difficult to estimate. While climate change is predicted to increase the frequency and magnitude of extreme precipitation events, the resulting impact on groundwater recharge remains poorly understood. We quantify empirical relations between precipitation characteristics and episodic groundwater recharge for a wide variety of geographic and land use types across North Carolina. We extract storm duration, magnitude, average rate, and hourly weighted intensity from long-term precipitation records over periods of 12–35 years at 10 locations. Using time series of water table fluctuations from nearby monitoring wells, we estimate relative recharge to precipitation ratios (RPR) to identify statistical trends. Increased RPR correlates with increased storm duration, whereas RPR decreases with increasing magnitude, average rate, and intensity of precipitation. Agricultural and urban areas exhibit the greatest decrease in RPR due to increasing storm magnitude, average rate, and intensity, while naturally vegetated areas exhibit a larger increase in RPR with increased storm duration. Though RPR is generally higher during the winter than the summer, this seasonal effect is magnified in the Appalachian and Piedmont regions. These statistical trends provide valuable insights into the likely consequences of climate and land use change for water resources in subtropical climates. If, as predicted, growing seasons lengthen and the intensity of storms increases with a warming climate, decreased recharge in Appalachia, the Piedmont, and rapidly growing urban areas of the American Southeast could further limit groundwater availability.

Hysteresis, regime shifts, and non-stationarity in aquifer recharge-storage-discharge systems

NASA Astrophysics Data System (ADS)

Klammler, Harald; Jawitz, James; Annable, Michael; Hatfield, Kirk; Rao, Suresh

2016-04-01

Based on physical principles and geological information we develop a parsimonious aquifer model for Silver Springs, one of the largest karst springs in Florida. The model structure is linear and time-invariant with recharge, aquifer head (storage) and spring discharge as dynamic variables at the springshed (landscape) scale. Aquifer recharge is the hydrological driver with trends over a range of time scales from seasonal to multi-decadal. The freshwater-saltwater interaction is considered as a dynamic storage mechanism. Model results and observed time series show that aquifer storage causes significant rate-dependent hysteretic behavior between aquifer recharge and discharge. This leads to variable discharge per unit recharge over time scales up to decades, which may be interpreted as a gradual and cyclic regime shift in the aquifer drainage behavior. Based on field observations, we further amend the aquifer model by assuming vegetation growth in the spring run to be inversely proportional to stream velocity and to hinder stream flow. This simple modification introduces non-linearity into the dynamic system, for which we investigate the occurrence of rate-independent hysteresis and of different possible steady states with respective regime shifts between them. Results may contribute towards explaining observed non-stationary behavior potentially due to hydrological regime shifts (e.g., triggered by gradual, long-term changes in recharge or single extreme events) or long-term hysteresis (e.g., caused by aquifer storage). This improved understanding of the springshed hydrologic response dynamics is fundamental for managing the ecological, economic and social aspects at the landscape scale.

Infiltration and recharge at Sand Hollow, an upland bedrock basin in southwestern Utah: Chapter I in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

USGS Publications Warehouse

Heilweil, Victor M.; Solomon, D. Kip; Gardner, Philip M.; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

2007-01-01

Permeable bedrock aquifers in arid regions of the southwestern United States are being used increasingly as a source of water for rapidly growing populations, yet in many areas little is known about recharge processes and amounts available for sustainable development. Environmental tracers were used in this study to investigate infiltration and recharge to the Navajo Sandstone at Sand Hollow in the eastern Mojave Desert of southwestern Utah. Average annual precipitation is about 210 millimeters per year. Tracers included bromide, chloride, deuterium, oxygen-18, and tritium. The basin-wide average recharge rate, based on ground-water chloride mass balance, is about 8 millimeters per year, or 4 percent of precipitation. However, infiltration and recharge are highly variable spatially within Sand Hollow. Recharge primarily occurs both as focused infiltration of runoff from areas of outcropping bedrock and as direct infiltration beneath coarse surficial soils. Locations with higher rates generally have lower vadose-zone and ground-water chloride concentrations, smaller vadose-zone oxygen-18 evaporative shifts, and higher ground-water tritium concentrations. Infiltration rates estimated from vadose-zone tritium concentrations at borehole sites within Sand Hollow range from 1 to more than 57 millimeters per year; rates calculated from average vadose-zone chloride concentrations between land surface and the bottom of the chloride bulge range from 0 to 9 millimeters per year; rates calculated from average vadose-zone chloride concentrations below the chloride bulge range from 0.5 to 15 millimeters per year; and rates calculated from ground-water chloride concentrations range from 3 to 60 millimeters per year. A two-end-member deuterium-mixing model indicates that about 85 percent of ground-water recharge in Sand Hollow occurs in the 50 percent of the basin covered by coarser soils and bedrock. Vadose-zone chloride concentrations at individual boreholes represent as much as

Fluoride release, recharge and mechanical property stability of various fluoride-containing resin composites.

PubMed

Naoum, S; Ellakwa, A; Martin, F; Swain, M

2011-01-01

To determine the fluoride release and recharge of three fluoride-containing resin composites when aged in deionized water (pH 6.5) and lactic acid (pH 4.0) and to assess mechanical properties of these composites following aging. Three fluoride-containing resin composites were analyzed in this study; a new giomer material named Beautifil II, Gradia Direct X, and Tetric EvoCeram. A glass ionomer cement, Fuji IX Extra, was also analyzed for comparison. Specimens were fabricated for two test groups: group 1 included 10 disc specimens initially aged 43 days in deionized water (five specimens) and lactic acid (five specimens). The fluoride release from these specimens was measured using a fluoride-specific electrode on nine specific test days during the aging period. Following 49 days of aging, each specimen was recharged in 5000 ppm neutral sodium fluoride solution for 5 minutes. Specimen recharge was then repeated on a weekly basis for 3 weeks. The subsequent fluoride rerelease was measured at 1, 3, and 7 days after each recharge episode. Group 2 included six disc specimens aged for 3 months in deionized water (three specimens) and lactic acid (three specimens). The hardness and elastic modulus of each specimen was measured using nano-indentation at intervals of 24 hours, 1 month, and 3 months after fabrication. Two-way factorial analysis of variance (ANOVA) and post-hoc (Tukey) testing was used to assess the influence of storage media (two levels) and composite type (three levels) on the fluoride release, fluoride rerelease, hardness, and elastic modulus of the assessed materials. The level of significance was set at p=0.05. All three composites demonstrated fluoride release and recharge when aged in both deionized water and lactic acid. The cumulative fluoride released from Beautifil II into both media was substantially greater than the fluoride released from Gradia Direct X and Tetric EvoCeram after 43 days aging and was significantly (p<0.05, ANOVA, Tukey test

Wastewater reclamation and recharge: A water management strategy for Albuquerque

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 tomore » 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.« less

Characteristics of and Areas Contributing Recharge to Public-Supply Springs in Massachusetts

USGS Publications Warehouse

Hansen, Bruce P.; Smith, Kirk P.

2004-01-01

The geohydrologic and physical characteristics were determined for 28 public-supply springs, 27 of which are in western Massachusetts. Discharge ranged from zero at various small intermittent springs to more than 240 gallons per minute at Waubeeka Springs in Williamstown, Massachusetts. To determine the annual variability of spring discharge, discharge from 12 springs was measured during different seasonal conditions from June 2001 to November 2002, and the discharge from Red Mill Spring in Clarksburg, Massachusetts was recorded continuously from April 2002 to November 2002. The area contributing recharge to each spring was delineated on the basis of the geohydrologic conditions determined from reconnaissance investigations; these areas ranged from 0.010 to 0.682 square mile. Ground-water recharge, estimated on the basis of average discharge and the areas contributing recharge, ranged from 0.5 to 24.4 inches per year. High ground-water recharge rates for some of the high-discharge springs indicate that the areas contributing recharge for these springs may be too small. Detailed water-table mapping in the vicinity of two low-discharge springs indicates that the area contributing recharge to some of the smaller springs may be smaller than the area indicated by reconnaissance investigation. Monthly flow durations and low flow statistics were determined for the index streamflow-gaging stations for a 25-year period from 1976 to 2000. Annual hydrographs were prepared for each index station from median streamflows at the 50-percent monthly flow duration, normalized by drainage area. A median monthly flow of 1 ft3/s/mi2 was used to split hydrographs into a high-flow period (November?May), and a low-flow period (June?October). The hydrographs were used to classify index stations into groups with similar median monthly flow durations. Index stations were divided into four regional groups, roughly paralleling the coast, to characterize streamflows for November to May; and

Etude du processus de changement vecu par des familles ayant decide d'adopter volontairement des comportements d'attenuation des changements climatiques

NASA Astrophysics Data System (ADS)

Leger, Michel T.

Les activites humaines energivores telles l'utilisation intensive de l'automobile, la surconsommation de biens et l'usage excessif d'electricite contribuent aux changements climatiques et autres problemes environnementaux. Bien que plusieurs recherches rapportent que l'etre humain est de plus en plus conscient de ses impacts sur le climat de la planete, ces memes recherches indiquent qu'en general, les gens continuent a se comporter de facon non ecologique. Que ce soit a l'ecole ou dans la communaute, plusieurs chercheurs en education relative a l'environnement estiment qu'une personne bien intentionnee est capable d'adopter des comportements plus respectueux de l'environnement. Le but de cette these etait de comprendre le processus d'integration de comportements d'attenuation des changements climatiques dans des familles. A cette fin, nous nous sommes fixe deux objectifs : 1) decrire les competences et les procedes qui favorisent l'adoption de comportements d'attenuation des changements climatiques dans des familles et 2) decrire les facteurs et les dynamiques familiales qui facilitent et limitent l'adoption de comportements d'attenuation des changements climatiques dans des familles. Des familles ont ete invitees a essayer des comportements personnels et collectifs d'attenuation des changements climatiques de sorte a integrer des modes de vie plus ecologiques. Sur une periode de huit mois, nous avons suivi leur experience de changement afin de mieux comprendre comment se produit le processus de changement dans des familles qui decident volontairement d'adopter des comportements d'attenuation des changements climatiques. Apres leur avoir fourni quelques connaissances de base sur les changements climatiques, nous avons observe le vecu de changement des familles durant huit mois d'essais a l'aide de journaux reflexifs, d'entretiens d'explicitation et du journal du chercheur. La these comporte trois articles scientifiques. Dans le premier article, nous presentons une

Recent Progress in Organic Electrodes for Li and Na Rechargeable Batteries.

PubMed

Lee, Sechan; Kwon, Giyun; Ku, Kyojin; Yoon, Kyungho; Jung, Sung-Kyun; Lim, Hee-Dae; Kang, Kisuk

2018-03-27

Organic rechargeable batteries, which use organics as electrodes, are excellent candidates for next-generation energy storage systems because they offer design flexibility due to the rich chemistry of organics while being eco-friendly and potentially cost efficient. However, their widespread usage is limited by intrinsic problems such as poor electronic conductivity, easy dissolution into liquid electrolytes, and low volumetric energy density. New types of organic electrode materials with various redox centers or molecular structures have been developed over the past few decades. Moreover, research aimed at enhancing electrochemical properties via chemical tuning has been at the forefront of organic rechargeable batteries research in recent years, leading to significant progress in their performance. Here, an overview of the current developments of organic rechargeable batteries is presented, with a brief history of research in this field. Various strategies for improving organic electrode materials are discussed with respect to tuning intrinsic properties of organics using molecular modification and optimizing their properties at the electrode level. A comprehensive understanding of the progress in organic electrode materials is provided along with the fundamental science governing their performance in rechargeable batteries thus a guide is presented to the optimal design strategies to improve the electrochemical performance for next-generation battery systems. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simulation of streamflow and estimation of ground-water recharge in the Upper Cibolo Creek Watershed, south-central Texas, 1992-2004

USGS Publications Warehouse

Ockerman, Darwin J.

2007-01-01

A watershed model (Hydrological Simulation Program?FORTRAN) was developed, calibrated, and tested by the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, San Antonio River Authority, San Antonio Water System, and Guadalupe-Blanco River Authority, to simulate streamflow and estimate ground-water recharge in the upper Cibolo Creek watershed in south-central Texas. Rainfall, evapotranspiration, and streamflow data were collected during 1992?2004 for model calibrations and simulations. Estimates of average ground-water recharge during 1992?2004 from simulation were 79,800 acre-feet (5.47 inches) per year or about 15 percent of rainfall. Most of the recharge (about 74 percent) occurred as infiltration of streamflow in Cibolo Creek. The remaining recharge occurred as diffuse infiltration of rainfall through the soil and rock layers and karst features. Most recharge (about 77 percent) occurred in the Trinity aquifer outcrop. The remaining 23 percent occurred in the downstream part of the watershed that includes the Edwards aquifer recharge zone (outcrop). Streamflow and recharge in the study area are greatly influenced by large storms. Storms during June 1997, October 1998, and July 2002 accounted for about 11 percent of study-area rainfall, 61 percent of streamflow, and 16 percent of the total ground-water recharge during 1992?2004. Annual streamflow and recharge also were highly variable. During 1999, a dry year with about 16 inches of rain and no measurable runoff at the watershed outlet, recharge in the watershed amounted to only 0.99 inch compared with 13.43 inches during 1992, a relatively wet year with about 54 inches of rainfall. Simulation of flood-control/recharge-enhancement structures showed that certain structures might reduce flood peaks and increase recharge. Simulation of individual structures on tributaries showed relatively little effect. Larger structures on the main stem of Cibolo Creek were more effective than structures

Alluvial groundwater recharge estimation in semi-arid environment using remotely sensed data

NASA Astrophysics Data System (ADS)

Coelho, Victor Hugo R.; Montenegro, Suzana; Almeida, Cristiano N.; Silva, Bernardo B.; Oliveira, Leidjane M.; Gusmão, Ana Cláudia V.; Freitas, Emerson S.; Montenegro, Abelardo A. A.

2017-05-01

Data limitations on groundwater (GW) recharge over large areas are still a challenge for efficient water resource management, especially in semi-arid regions. Thus, this study seeks to integrate hydrological cycle variables from satellite imagery to estimate the spatial distribution of GW recharge in the Ipanema river basin (IRB), which is located in the State of Pernambuco in Northeast Brazil. Remote sensing data, including monthly maps (2011-2012) of rainfall, runoff and evapotranspiration, are used as input for the water balance method within Geographic Information Systems (GIS). Rainfall data are derived from the TRMM Multi-satellite Precipitation Analysis (TMPA) Version 7 (3B43V7) product and present the same monthly average temporal distributions from 15 rain gauges that are distributed over the study area (r = 0.93 and MAE = 12.7 mm), with annual average estimates of 894.3 (2011) and 300.7 mm (2012). The runoff from the Natural Resources Conservation Service (NRCS) method, which is based on regional soil information and Thematic Mapper (TM) sensor image, represents 29% of the TMPA rainfall that was observed across two years of study. Actual evapotranspiration data, which were provided by the SEBAL application of MODIS images, present annual averages of 1213 (2011) and 1067 (2012) mm. The water balance results reveal a large inter-annual difference in the IRB GW recharge, which is characterized by different rainfall regimes, with averages of 30.4 (2011) and 4.7 (2012) mm year-1. These recharges were mainly observed between January and July in regions with alluvial sediments and highly permeable soils. The GW recharge approach with remote sensing is compared to the WTF (Water Table Fluctuation) method, which is used in an area of alluvium in the IRB. The estimates from these two methods exhibit reliable annual agreement, with average values of 154.6 (WTF) and 124.6 (water balance) mm in 2011. These values correspond to 14.89 and 13.53% of the rainfall that was

Lithium-ion rechargeable batteries

NASA Astrophysics Data System (ADS)

Megahed, Sid; Scrosati, Bruno

The large availability of insertion electrodes capable to exchange substantial quantities of lithium ions with relatively fast kinetics, has promoted the development of various types of rechargeable lithium batteries having different design, size, capacity, power and energy capabilities. All these lithium batteries offer a series of considerable specific advantages, such as high energy density and relatively low cost. However, their widespread utilization is still influenced by the high reactivity of the metal which, from one side assures the high energetic content, from the other induces safety hazards and limited cycleability. Attempts to overcome this shortcoming have resulted in the development of batteries where the lithium metal is most commonly replaced by a carbon electrode. Penalties in energy density in respect to the lithium systems and counterbalanced by an expected safer and longer cycle life from the carbon systems. Although a very recent innovation, the rocking-chair idea has already found enthusiastic support in many research laboratories which are presently involved in its investigation and development. As a result of this, small size, lithium rockingchair batteries or, as otherwise named 'lithium-ion batteries', are currently under development in Japan, USA and Europe. In this review paper we describe the properties of the anode, cathode and electrolyte materials which presently seem to be the most promising for the development of these batteries, and we will attempt to evaluate the impact that the rockingchair concept may ultimately have on the progress of rechargeable lithium battery technology. We will also summarize the status of practical rocking-chair batteries for various emerging applications.

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.

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.

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.

Problems associated with estimating ground water discharge and recharge from stream-discharge records

USGS Publications Warehouse

Halford, K.J.; Mayer, G.C.

2000-01-01

Ground water discharge and recharge frequently have been estimated with hydrograph-separation techniques, but the critical assumptions of the techniques have not been investigated. The critical assumptions are that the hydraulic characteristics of the contributing aquifer (recession index) can be estimated from stream-discharge records; that periods of exclusively ground water discharge can be reliably identified; and that stream-discharge peaks approximate the magnitude and tinting of recharge events. The first assumption was tested by estimating the recession index from st earn-discharge hydrographs, ground water hydrographs, and hydraulic diffusivity estimates from aquifer tests in basins throughout the eastern United States and Montana. The recession index frequently could not be estimated reliably from stream-discharge records alone because many of the estimates of the recession index were greater than 1000 days. The ratio of stream discharge during baseflow periods was two to 36 times greater than the maximum expected range of ground water discharge at 12 of the 13 field sites. The identification of the ground water component of stream-discharge records was ambiguous because drainage from bank-storage, wetlands, surface water bodies, soils, and snowpacks frequently exceeded ground water discharge and also decreased exponentially during recession periods. The timing and magnitude of recharge events could not be ascertained from stream-discharge records at any of the sites investigated because recharge events were not directly correlated with stream peaks. When used alone, the recession-curve-displacement method and other hydrograph-separation techniques are poor tools for estimating ground water discharge or recharge because the major assumptions of the methods are commonly and grossly violated. Multiple, alternative methods of estimating ground water discharge and recharge should be used because of the uncertainty associated with any one technique.

Using environmental tracers and transient hydraulic heads to estimate groundwater recharge and conductivity

NASA Astrophysics Data System (ADS)

Erdal, Daniel; Cirpka, Olaf A.

2017-04-01

Regional groundwater flow strongly depends on groundwater recharge and hydraulic conductivity. While conductivity is a spatially variable field, recharge can vary in both space and time. None of the two fields can be reliably observed on larger scales, and their estimation from other sparse data sets is an open topic. Further, common hydraulic-head observations may not suffice to constrain both fields simultaneously. In the current work we use the Ensemble Kalman filter to estimate spatially variable conductivity, spatiotemporally variable recharge and porosity for a synthetic phreatic aquifer. We use transient hydraulic-head and one spatially distributed set of environmental tracer observations to constrain the estimation. As environmental tracers generally reside for a long time in an aquifer, they require long simulation times and carries a long memory that makes them highly unsuitable for use in a sequential framework. Therefore, in this work we use the environmental tracer information to precondition the initial ensemble of recharge and conductivities, before starting the sequential filter. Thereby, we aim at improving the performance of the sequential filter by limiting the range of the recharge to values similar to the long-term annual recharge means and by creating an initial ensemble of conductivities that show similar pattern and values to the true field. The sequential filter is then used to further improve the parameters and to estimate the short term temporal behavior as well as the temporally evolving head field needed for short term predictions within the aquifer. For a virtual reality covering a subsection of the river Neckar it is shown that the use of environmental tracers can improve the performance of the filter. Results using the EnKF with and without this preconditioned initial ensemble are evaluated and discussed.

A Generalized Subsurface Flow Parameterization Considering Subgrid Spatial Variability of Recharge and Topography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Maoyi; Liang, Xu; Leung, Lai R.

2008-12-05

Subsurface flow is an important hydrologic process and a key component of the water budget, especially in humid regions. In this study, a new subsurface flow formulation is developed that incorporates spatial variability of both topography and recharge. It is shown through theoretical derivation and case studies that the power law and exponential subsurface flow parameterizations and the parameterization proposed by Woods et al.[1997] are all special cases of the new formulation. The subsurface flows calculated using the new formulation compare well with values derived from observations at the Tulpehocken Creek and Walnut Creek watersheds. Sensitivity studies show that whenmore » the spatial variability of topography or recharge, or both is increased, the subsurface flows increase at the two aforementioned sites and the Maimai hillslope. This is likely due to enhancement of interactions between the groundwater table and the land surface that reduce the flow path. An important conclusion of this study is that the spatial variability of recharge alone, and/or in combination with the spatial variability of topography can substantially alter the behaviors of subsurface flows. This suggests that in macroscale hydrologic models or land surface models, subgrid variations of recharge and topography can make significant contributions to the grid mean subsurface flow and must be accounted for in regions with large surface heterogeneity. This is particularly true for regions with humid climate and relatively shallow groundwater table where the combined impacts of spatial variability of recharge and topography are shown to be more important. For regions with arid climate and relatively deep groundwater table, simpler formulations, especially the power law, for subsurface flow can work well, and the impacts of subgrid variations of recharge and topography may be ignored.« less

Coupling of Groundwater Recharge and Biodegradation of Subsurface Crude-Oil Contamination (Invited)

NASA Astrophysics Data System (ADS)

Bekins, B. A.; Hostettler, F. D.; Delin, G. N.; Herkelrath, W. N.; Warren, E.; Campbell, P.; Rosenbauer, R. J.; Cozzarelli, I.

2010-12-01

Surface hydrologic properties controlling groundwater recharge can have a large effect on biodegradation rates in the subsurface. Two studies of crude oil contamination show that degradation rates are dramatically increased where recharge rates are enhanced. The first site, located near Bemidji, Minnesota, was contaminated in August, 1979 when oil from a pipeline rupture infiltrated into a surficial glacial outwash aquifer. Discrete oil phases form three separate pools at the water table, the largest of which is 25x75 m at a depth of 6-8 m. Gas and water concentrations and microbial community data show that methanogenic conditions prevail in this oil pool. There is extreme spatial dependence in the degradation rates such that most of the n-alkanes have been degraded in the upgradient end, but in the downgradient end n-alkane concentrations are nearly unaltered from the original spill. Recharge rates through the two ends of the oil body were estimated using a water table fluctuation method. In 2002, the more degraded end received 15.2 cm of recharge contrasted to 10.7 cm at the less degraded end. The enhanced recharge is caused by topographic focusing of runoff toward a local depression. Microbial data using the Most Probable Number method show that the methanogen concentrations are 10-100 times greater in the more degraded end of the oil body suggesting that a growth nutrient is supplied by recharge. A decrease in partial pressure of N2 compared to Ar in the soil gas indicates nitrogen fixation probably meets N requirements (Amos et al., 2005, WRR, doi:10.1029/2004WR003433). Organic phosphorus is the main form of P in infiltrating pore water and concentration decreases with depth. The second site is located 40 km southeast of the Bemidji site at an oil pipeline pumping station near Cass Lake, Minnesota. This site was contaminated by oil leaking from a pipe coupling for an unknown duration of time between 1971 and 2002. The oil body at this site lies under a fenced

Estimates of Ground-Water Recharge in Wadis of Arid, Mountainous Areas Using the Chloride Mass-Balance Approach

NASA Astrophysics Data System (ADS)

Wood, W. W.; Wood, W. W.

2001-05-01

Evaluation of ground-water supply in arid areas requires estimation of annual recharge. Traditional physical-based hydrologic estimates of ground-water recharge result in large uncertainties when applied in arid, mountainous environments because of infrequent, intense rainfall events, destruction of water-measuring structures associated with those events, and consequent short periods of hydrologic records. To avoid these problems and reduce the uncertainty of recharge estimates, a chloride mass-balance (CMB) approach was used to provide a time-integrated estimate. Seven basins exhibiting dry-stream beds (wadis) in the Asir and Hijaz Mountains, western Saudi Arabia, were selected to evaluate the method. Precipitation among the basins ranged from less than 70 mm/y to nearly 320 mm/y. Rain collected from 35 locations in these basins averaged 2.0 mg/L chloride. Ground water from 140 locations in the wadi alluvium averaged 200 mg/L chloride. This chloride concentration ratio of precipitation to ground water suggests that on average, approximately 1 percent of the rainfall is recharged, while the remainder is lost to evaporation. Ground-water recharge from precipitation in individual basins ranged from less than 1 to nearly 4 percent and was directly proportional to total precipitation. Independent calculations of recharge using Darcy's Law were consistent with these findings and are within the range typically found in other arid areas of the world. Development of ground water has lowered the water level beneath the wadis and provided more storage thus minimizing chloride loss from the basin by river discharge. Any loss of chloride from the basin results in an overestimate of the recharge flux by the chloride-mass balance approach. In well-constrained systems recharge in arid, mountainous areas where the mass of chloride entering and leaving the basin is known or can be reasonably estimated, the CMB approach provides a rapid, inexpensive method for estimating time

Using stable isotopes to characterize groundwater recharge sources in the volcanic island of Madeira, Portugal

NASA Astrophysics Data System (ADS)

Prada, Susana; Cruz, J. Virgílio; Figueira, Celso

2016-05-01

The hydrogeology of volcanic islands remains poorly understood, despite the fact that populations that live on them rely on groundwater as a primary water source. This situation is exacerbated by their complex structure, geological heterogeneity, and sometimes active volcanic processes that hamper easy analysis of their hydrogeological dynamics. Stable isotope analysis is a powerful tool that has been used to assess groundwater dynamics in complex terrains. In this work, stable isotopes are used to better understand the hydrogeology of Madeira Island and provide a case-study that can serve as a basis for groundwater studies in other similar settings. The stable isotopic composition (δ18O and δ2H) of rain at the main recharge areas of the island is determined, as well as the sources and altitudes of recharge of several springs, groundwater in tunnels and wells. The water in tunnels was found to be recharged almost exclusively by rain in the deforested high plateaus, whilst several springs associated with shallow perched aquifers are recharged from rain and cloud water interception by the vegetated slopes. Nevertheless some springs thought to be sourced from deep perched aquifers, recharge in the central plateaus, and their isotopic composition is similar to the water in the tunnels. Recharge occurs primarily during autumn and winter, as evidenced by the springs and tunnels Water Lines (WL). The groundwater in wells appears to originate from runoff from rain that falls along the slopes that infiltrates near the streams' mouths, where the wells are located. This is evident by the evaporation line along which the wells plot. Irrigation water is also a possible source of recharge. The data is compatible with the hydrogeological conceptual model of Madeira. This work also shows the importance of cloud water interception as a net contributor to groundwater recharge, at least in the perched aquifers that feed numerous springs. As the amount of rainfall is expected to

Event Water Balance and Recharge at the Panola Mountain Research Watershed, Georgia, U.S.A.

NASA Astrophysics Data System (ADS)

Riley, J. W.; Aulenbach, B. T.

2016-12-01

Investigating catchment storage and runoff pathways allows a better mechanistic understanding of stream flow generation processes. This information can be used to elucidate processes such as those influencing baseflow that support human consumption and ecological needs. Here we describe storm runoff water budgets from 483 rain events to determine the conditions under which precipitation infiltrates to deeper storage that supports baseflow. Further, we examine the storage and recharge behavior of different storm characteristics and antecedent conditions. We use a simple water budget approach to achieve this in which Deep Recharge = (Precipitation) - (Storm Runoff) - (Event Change in Soil Storage). Hydrograph separation was used to determine the storm periods and split storm runoff into baseflow and quickflow. Quickflow was assumed to account for the event water lost to the stream. Data from volumetric water content sensors were used to calculate the soil profile water storage and the change in water storage over the course of an event. The remaining water after these two components was assumed to represent water available for deeper recharge. The median event quickflow:precipitation ratio was 11.8%. Event soil moisture recharge in the top one meter of soil accounted for a median of 65.3% of precipitation. Quickflow and shallow soil moisture recharge accounted for a median of 77.1% of the precipitation delivered to the watershed. Water budgets indicated that 43% of the events provided water for deeper recharge. Of these events, however, only 28% provided 50 mm or more of deep recharge. Because the focus was on events, when humidity was high and the vapor pressure deficit (VPD) was low, we ignored the role of evapotranspiration. However, interception, which was not accounted for, would have resulted in less storm precipitation than was measured at the watershed rain gage. Furthermore, transpiration may have altered the post-storm water balance when VPD increased and

High energy density rechargeable magnesium battery using earth-abundant and non-toxic elements

PubMed Central

Orikasa, Yuki; Masese, Titus; Koyama, Yukinori; Mori, Takuya; Hattori, Masashi; Yamamoto, Kentaro; Okado, Tetsuya; Huang, Zhen-Dong; Minato, Taketoshi; Tassel, Cédric; Kim, Jungeun; Kobayashi, Yoji; Abe, Takeshi; Kageyama, Hiroshi; Uchimoto, Yoshiharu

2014-01-01

Rechargeable magnesium batteries are poised to be viable candidates for large-scale energy storage devices in smart grid communities and electric vehicles. However, the energy density of previously proposed rechargeable magnesium batteries is low, limited mainly by the cathode materials. Here, we present new design approaches for the cathode in order to realize a high-energy-density rechargeable magnesium battery system. Ion-exchanged MgFeSiO4 demonstrates a high reversible capacity exceeding 300 mAh·g−1 at a voltage of approximately 2.4 V vs. Mg. Further, the electronic and crystal structure of ion-exchanged MgFeSiO4 changes during the charging and discharging processes, which demonstrates the (de)insertion of magnesium in the host structure. The combination of ion-exchanged MgFeSiO4 with a magnesium bis(trifluoromethylsulfonyl)imide–triglyme electrolyte system proposed in this work provides a low-cost and practical rechargeable magnesium battery with high energy density, free from corrosion and safety problems. PMID:25011939

Echo Meadows Project Winter Artificial Recharge.

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 Echomore » 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

Investigating local variation in groundwater recharge along a topographic gradient, Walnut Creek, Iowa, USA

USGS Publications Warehouse

Schilling, K.E.

2009-01-01

Groundwater recharge is an important component to hydrologic studies but is known to vary considerably across the landscape. The purpose of this study was to examine 4 years of water-level behavior in a transect of four water-table wells installed at Walnut Creek, Iowa, USA to evaluate how groundwater recharge varied along a topographic gradient. The amount of daily water-table rise (WTR) in the wells was summed at monthly and annual scales and estimates of specific yield (Sy) were used to convert the WTR to recharge. At the floodplain site, Sy was estimated from the ratio of WTR to total rainfall and in the uplands was based on the ratio of baseflow to WTR. In the floodplain, where the water table is shallow, recharge occurred throughout the year whenever precipitation occurred. In upland areas where the water table was deeper, WTR occurred in a stepped fashion and varied by season. Results indicated that the greatest amount of water-table rise over the 4-year period was observed in the floodplain (379 mm), followed by the upland (211 mm) and sideslopes (122 mm). Incorporating spatial variability in recharge in a watershed will improve groundwater resource evaluation and flow and transport modeling. ?? Springer-Verlag 2008.

New non-linear model of groundwater recharge: Inclusion of memory, heterogeneity and visco-elasticity

NASA Astrophysics Data System (ADS)

Spannenberg, Jescica; Atangana, Abdon; Vermeulen, P. D.

2017-09-01

Fractional differentiation has adequate use for investigating real world scenarios related to geological formations associated with elasticity, heterogeneity, viscoelasticity, and the memory effect. Since groundwater systems exist in these geological formations, modelling groundwater recharge as a real world scenario is a challenging task to do because existing recharge estimation methods are governed by linear equations which make use of constant field parameters. This is inadequate because in reality these parameters are a function of both space and time. This study therefore concentrates on modifying the recharge equation governing the EARTH model, by application of the Eton approach. Accordingly, this paper presents a modified equation which is non-linear, and accounts for parameters in a way that it is a function of both space and time. To be more specific, herein, recharge and drainage resistance which are parameters within the equation, became a function of both space and time. Additionally, the study entailed solving the non-linear equation using an iterative method as well as numerical solutions by means of the Crank-Nicolson scheme. The numerical solutions were used alongside the Riemann-Liouville, Caputo-Fabrizio, and Atangana-Baleanu derivatives, so that account was taken for elasticity, heterogeneity, viscoelasticity, and the memory effect. In essence, this paper presents a more adequate model for recharge estimation.

Long-term dentin remineralization by poly(amido amine) and rechargeable calcium phosphate nanocomposite after fluid challenges.

PubMed

Liang, Kunneng; Xiao, Shimeng; Wu, Junling; Li, Jiyao; Weir, Michael D; Cheng, Lei; Reynolds, Mark A; Zhou, Xuedong; Xu, Hockin H K

2018-04-01

Previous studies investigated short-term dentin remineralization; studies on long-term dentin remineralization after fluid challenges mimicking fluids in oral environment are lacking. The objective of this study was to develop a long-term remineralization method to via poly(amido amine) (PAMAM) and rechargeable composite containing nanoparticles of amorphous calcium phosphate (NACP) after fluid challenges for the first time. NACP composite was immersed at pH 4 to exhaust its calcium (Ca) and phosphate (P) ions, and then recharged with Ca and P ions, to test the remineralization of the exhausted and recharged NACP composite. Dentin was acid-etched with 37% phosphoric acid. Four groups were prepared: (1) dentin control, (2) dentin with PAMAM, (3) dentin with the recharged NACP composite, and (4) dentin with PAMAM plus recharged NACP composite. PAMAM-coated dentin was immersed in phosphate-buffered saline with shaking for 72 days, because there is fluid flow in the mouth which could potentially detach the PAMAM from dentin. Specimens were treated with a cyclic artificial saliva/lactic acid regimen for 35 days. After 72days of immersion plus shaking, the PAMAM still successfully fulfilled its mineralization nucleation. The recharged NACP composite still provided acid-neutralization and ion re-release, which did not decrease with increasing the number of recharge cycles. The immersed-PAMAM plus NACP achieved complete dentin remineralization and restored the hardness to that of healthy dentin. In conclusion, superior long-term remineralization of the PAMAM plus NACP method was demonstrated for the first time. The immersed-PAMAM plus recharged NACP completely remineralized the pre-demineralized dentin, even after prolonged fluid-challenge similar to that in oral environment. The novel PAMAM plus NACP composite method is promising to provide long-term tooth protection and caries inhibition. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Ltd. All

Evaluating the Impacts of Grassland Conversions to Experimental Forest on Groundwater Recharge in the Nebraska Sand Hills

NASA Astrophysics Data System (ADS)

Adane, Zablon A.

The Nebraska Sand Hills grasslands provide the greatest groundwater recharge rates in the High Plains Aquifer. However, the grasslands and their ecological services have become vulnerable to land use change and degradation. This study used a series of field data to investigate the effects of grassland conversions to forest on recharge rates in a century-old experimental forest in the Sand Hills. The results show that the impact of grassland conversion on recharge was dependent on the species and plantation density. Estimated recharge rates beneath the dense plantations represent reductions of 86-94% relative to the native grassland. Results of 1H Nuclear Magnetic Resonance spectral analysis suggested that the surface soil organic carbon beneath pine plantations also contain up to 3 times the ratio of hydrophobic components than the native grasslands and may alter the soil hydraulic properties. This investigation further uncovered a previously overlooked feedback between the effect of soil organic carbon chemical shift generated by the ponderosa pine needle litter decomposition; namely that the alteration may have a link to reduced groundwater recharge rates. Thus, a global optimizer algorithm was used to estimate the effective soil hydraulic parameters from monthly soil moisture contents and recharge rates were then estimated through HYDRUS 1-D numerical modeling for grassland and pine forest soils. The impact of grassland conversion to pine was an overall reduction of groundwater recharge by nearly 100%. These outcomes highlight the significance of the grasslands for recharge, in the Sand Hills and the sustainability of the High Plains Aquifer.

Ground-water recharge to and storage in the regolith-fractured crystalline rock aquifer system, Guilford County, North Carolina

USGS Publications Warehouse

Daniel, C. C.; Harned, D.A.

1998-01-01

Quantitative information concerning recharge rates to aquifers and ground water in storage is needed to manage the development of ground- water resources. The amount of ground water available from the regolith-fractured crystalline rock aquifer system in Guilford County, North Carolina, is largely unknown. If historical patterns seen throughout the Piedmont continue into the future, the number of ground- water users in the county can be expected to increase. In order to determine the maximum population that can be supplied by ground water, planners and managers of suburban development must know the amount of ground water that can be withdrawn without exceeding recharge and(or) overdrafting water in long-term storage. Results of the study described in this report help provide this information. Estimates of seasonal and long-term recharge rates were estimated for 15 selected drainage basins and subbasins using streamflow data and an anlytical technique known as hydrograph separation. Methods for determining the quantity of ground water in storage also are described. Guilford County covers approximately 658 square miles in the central part of the Piedmont Province. The population of the county in 1990 was about 347,420; approximately 21 percent of the population depends on ground water as a source of potable supplies. Ground water is obtained from wells tapping the regolith-fractured crystalline rock aquifer system that underlies all of the county. Under natural conditions, recharge to the ground-water system in the county is derived from infiltration of precipitation. Ground-water recharge from precipitation cannot be measured directly; however, an estimate of the amount of precipitation that infiltrates into the ground and ultimately reaches the streams of the region can be determined by the technique of hydrograph separation. Data from 19 gaging stations that measure streamflow within or from Guilford County were analyzed to produce daily estimates of ground

78 FR 62495 - Special Conditions: Learjet Model 35, 35A, 36, and 36A Airplanes; Rechargeable Lithium-Ion...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-22

...; Rechargeable Lithium-Ion Batteries and Battery Systems AGENCY: Federal Aviation Administration (FAA), DOT... rechargeable lithium-ion batteries and battery systems. These batteries have certain failure, operational, and... installing equipment that uses rechargeable lithium-ion battery systems in Learjet Model 35, 35A, 36, and 36A...

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.

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

Diethylstilbestrol (DES) and Cancer

MedlinePlus

... Genetics Services Directory Cancer Prevention Overview Research Diethylstilbestrol (DES) and Cancer On This Page What is DES? ... outlined in the table below. Fertility Problems in DES Daughters ( 7 ) Fertility Complication Hazard Ratio Percent Cumulative ...

Battery charging control methods, electric vehicle charging methods, battery charging apparatuses and rechargeable battery systems

DOEpatents

Tuffner, Francis K [Richland, WA; Kintner-Meyer, Michael C. W. [Richland, WA; Hammerstrom, Donald J [West Richland, WA; Pratt, Richard M [Richland, WA

2012-05-22

Battery charging control methods, electric vehicle charging methods, battery charging apparatuses and rechargeable battery systems. According to one aspect, a battery charging control method includes accessing information regarding a presence of at least one of a surplus and a deficiency of electrical energy upon an electrical power distribution system at a plurality of different moments in time, and using the information, controlling an adjustment of an amount of the electrical energy provided from the electrical power distribution system to a rechargeable battery to charge the rechargeable battery.

Novel electrolyte chemistries for Mg-Ni rechargeable batteries.

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 measuredmore » 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.« less

Relative Impacts of Low Permeability Subsurface Deposits on Recharge Basin Infiltration Rates

NASA Astrophysics Data System (ADS)

Oconnell, P.; Becker, M.; Pham, C.; Rodriguez, G.; Hutchinson, A.; Plumlee, M.

2017-12-01

Artificial recharge of aquifers through spreading basins has become an important component of water management in semi-arid climates. The rate at which water can be recharged in these basins is limited by the natural vertical permeability of the underlying deposits which may be highly variable both laterally and vertically. To help understand hydrostratigraphic controls on recharge, a newly constructed basin was surveyed and instrumented. Prior to flooding the basin, lithology was characterized by shallow hand coring, direct push coring, ground penetrating radar, and electrical resistivity. After flooding, recharge was monitored through piezometers, electrical resistivity, and a network of fiber optic distributed temperature sensing (DTS). The DTS network used temperature as a tracer to measure infiltration rate on 25 cm intervals both laterally and vertically. Several hundred paired DTS time series datasets (from fiber optic cables located at 0 and 0.5 meters below ground surface) were processed with the cross-wavelet transform (XWT) to calculate spatially and temporally continuous infiltration rates, which can be interpolated and animated to visualize heterogeneity. Time series data from 8-meter deep, vertically oriented DTS cables reveal depth intervals where infiltration rates vary. Inverted resistivity sections from repeated dipole-dipole surveys along the sidewall of a spreading basin exhibit a positive correlation with the distribution of relatively high and low infiltration rates, indicating zones of preferential downward (efficient) and lateral (inefficient) flow, respectively. In contrast to other monitored basins, no perching was observed in the vertically oriented DTS cables. The variation in recharge across the basin and the appearance of subsurface lateral flow can be explained in context of the alluvial depositional environment.

Intermediate tree cover can maximize groundwater recharge in the seasonally dry tropics

PubMed Central

Ilstedt, U.; Bargués Tobella, A.; Bazié, H. R.; Bayala, J.; Verbeeten, E.; Nyberg, G.; Sanou, J.; Benegas, L.; Murdiyarso, D.; Laudon, H.; Sheil, D.; Malmer, A.

2016-01-01

Water scarcity contributes to the poverty of around one-third of the world’s people. Despite many benefits, tree planting in dry regions is often discouraged by concerns that trees reduce water availability. Yet relevant studies from the tropics are scarce, and the impacts of intermediate tree cover remain unexplored. We developed and tested an optimum tree cover theory in which groundwater recharge is maximized at an intermediate tree density. Below this optimal tree density the benefits from any additional trees on water percolation exceed their extra water use, leading to increased groundwater recharge, while above the optimum the opposite occurs. Our results, based on groundwater budgets calibrated with measurements of drainage and transpiration in a cultivated woodland in West Africa, demonstrate that groundwater recharge was maximised at intermediate tree densities. In contrast to the prevailing view, we therefore find that moderate tree cover can increase groundwater recharge, and that tree planting and various tree management options can improve groundwater resources. We evaluate the necessary conditions for these results to hold and suggest that they are likely to be common in the seasonally dry tropics, offering potential for widespread tree establishment and increased benefits for hundreds of millions of people. PMID:26908158

Quantifying Modern Recharge and Depletion Rates of the Nubian Aquifer in Egypt

NASA Astrophysics Data System (ADS)

Ahmed, Mohamed; Abdelmohsen, Karem

2018-07-01

Egypt is currently seeking additional freshwater resources to support national reclamation projects based mainly on the Nubian aquifer groundwater resources. In this study, temporal (April 2002 to June 2016) Gravity Recovery and Climate Experiment (GRACE)-derived terrestrial water storage (TWSGRACE) along with other relevant datasets was used to monitor and quantify modern recharge and depletion rates of the Nubian aquifer in Egypt (NAE) and investigate the interaction of the NAE with artificial lakes. Results indicate: (1) the NAE is receiving a total recharge of 20.27 ± 1.95 km3 during 4/2002-2/2006 and 4/2008-6/2016 periods, (2) recharge events occur only under excessive precipitation conditions over the Nubian recharge domains and/or under a significant rise in Lake Nasser levels, (3) the NAE is witnessing a groundwater depletion of - 13.45 ± 0.82 km3/year during 3/2006-3/2008 period, (4) the observed groundwater depletion is largely related to exceptional drought conditions and/or normal baseflow recession, and (5) a conjunctive surface water and groundwater management plan needs to be adapted to develop sustainable water resources management in the NAE. Findings demonstrate the use of global monthly TWSGRACE solutions as a practical, informative, and cost-effective approach for monitoring aquifer systems across the globe.

Quantifying Modern Recharge and Depletion Rates of the Nubian Aquifer in Egypt

NASA Astrophysics Data System (ADS)

Ahmed, Mohamed; Abdelmohsen, Karem

2018-02-01

Egypt is currently seeking additional freshwater resources to support national reclamation projects based mainly on the Nubian aquifer groundwater resources. In this study, temporal (April 2002 to June 2016) Gravity Recovery and Climate Experiment (GRACE)-derived terrestrial water storage (TWSGRACE) along with other relevant datasets was used to monitor and quantify modern recharge and depletion rates of the Nubian aquifer in Egypt (NAE) and investigate the interaction of the NAE with artificial lakes. Results indicate: (1) the NAE is receiving a total recharge of 20.27 ± 1.95 km3 during 4/2002-2/2006 and 4/2008-6/2016 periods, (2) recharge events occur only under excessive precipitation conditions over the Nubian recharge domains and/or under a significant rise in Lake Nasser levels, (3) the NAE is witnessing a groundwater depletion of - 13.45 ± 0.82 km3/year during 3/2006-3/2008 period, (4) the observed groundwater depletion is largely related to exceptional drought conditions and/or normal baseflow recession, and (5) a conjunctive surface water and groundwater management plan needs to be adapted to develop sustainable water resources management in the NAE. Findings demonstrate the use of global monthly TWSGRACE solutions as a practical, informative, and cost-effective approach for monitoring aquifer systems across the globe.