WorldWideScience

Sample records for high-pressure-system recharge gas

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

    Science.gov (United States)

    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

  2. Experimental characterization of interfacial behaviors of hydrocarbon mixtures in high pressure systems

    Energy Technology Data Exchange (ETDEWEB)

    Nie, Hui

    2012-07-01

    The interfacial properties and behaviors of the hydrocarbon mixtures in high pressure systems were experimentally and numerically studied during this work. Simultaneously measurements of phase densities, vapor phase compositions, and interfacial tensions were performed using the High Pressure interfacial tension facility in the Statoil Research Center, Trondheim. Numerical computations of interfacial properties at the non-homogeneous flat vapor/liquid interface were carried out with the Gradient Theory model so as to evaluate the method for future simulations of interfacial characteristics of the real gas condensate. It was found that the accuracy of the Gradient Theory is superior to the Parachor Method, which has been traditionally used in the oil industry for its interfacial tension predictions. In the laboratory, the high pressure Anton Paar oscillation tube densitometer was employed for liquid and vapor phase density measurements, and the pendant drop method was used to generate the interfacial tension data. The Online Gas Chromatography (GC) cell was utilized to obtain the vapor phase compositions under high pressure conditions. In this study, the methane + ethane + n-pentane system is considered to be a synthetic condensate, which mimics the thermodynamic behavior of a real nature gas in high pressure gas/liquid separation systems. The experimental temperature is set to 294.15 K since it is close to the scrubber' normal working temperature. Both the phase densities and interfacial tensions of the methane + n-pentane, ethane + n-pentane and methane + ethane + n-pentane systems were measured in the interfacial tension rig. The experimental data is crucial for the understanding, experimental characterizing, and developing the thermodynamic model in predicting interfacial properties and the phase behaviors governing the high pressure vapor/liquid separation process, which is the main purpose of this research. The Gradient Theory method, combined with the

  3. Rechargeable batteries applications handbook

    CERN Document Server

    1998-01-01

    Represents the first widely available compendium of the information needed by those design professionals responsible for using rechargeable batteries. This handbook introduces the most common forms of rechargeable batteries, including their history, the basic chemistry that governs their operation, and common design approaches. The introduction also exposes reader to common battery design terms and concepts.Two sections of the handbook provide performance information on two principal types of rechargeable batteries commonly found in consumer and industrial products: sealed nickel-cad

  4. Recharge unit provides for optimum recharging of battery cells

    Science.gov (United States)

    Baer, D.; Ford, F. E.

    1968-01-01

    Percent recharge unit permits each cell of a rechargeable battery to be charged to a preset capacity of the cell. The unit automatically monitors and controls a rechargeable battery subjected to charge-discharge cycling tests.

  5. Modelling of rechargeable NiMH batteries

    NARCIS (Netherlands)

    Ledovskikh, A.; Verbitskiy, E.; Ayeb, A.; Notten, P.H.L.

    2003-01-01

    A new mathematical model has been developed for rechargeable NiMH batteries, which is based on the occurring physical–chemical processes inside. This model enables one to simultaneously simulate the battery voltage, internal gas pressures (both PO2 and PH2) and temperature during battery operation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Visser, Ate [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Moran, Jean E. [California State Univ. East Bay (CalState), Hayward, CA (United States); Singleton, Michael J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Esser, Bradley K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-03-21

    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 part 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.

  7. Wireless rechargeable sensor networks

    CERN Document Server

    Yang, Yuanyuan

    2015-01-01

    This SpringerBrief provides a concise guide to applying wireless energy transfer techniques in traditional battery-powered sensor networks. It examines the benefits and challenges of wireless power including efficiency and reliability. The authors build a wireless rechargeable sensor networks from scratch and aim to provide perpetual network operation. Chapters cover a wide range of topics from the collection of energy information and recharge scheduling to joint design with typical sensing applications such as data gathering. Problems are approached using a natural combination of probability

  8. Using noble gases to investigate mountain-front recharge

    Science.gov (United States)

    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.

  9. Groundwater recharge: Accurately representing evapotranspiration

    CSIR Research Space (South Africa)

    Bugan, Richard DH

    2011-09-01

    Full Text Available Groundwater recharge is the basis for accurate estimation of groundwater resources, for determining the modes of water allocation and groundwater resource susceptibility to climate change. Accurate estimations of groundwater recharge with models...

  10. Rechargeable power supply

    NARCIS (Netherlands)

    Den Uijl, S.; Bouman, C.; Smit, W.

    2006-01-01

    The invention relates to a rechargeable power supply suitable to be used in a battery-operated device comprising at least one supercapacitor and at least a first and a second DC-DC converter connected in series, wherein the supercapacitor is connectable to an entry of the first DC-DC converter and

  11. A preliminary analysis of the groundwater recharge to the Karoo formations, mid-Zambesi basin, Zimbabwe

    DEFF Research Database (Denmark)

    Larsen, Flemming; Owen, R.; Dahlin, T.

    2002-01-01

    of the mid-Zambezi basin (Fig. 1). The potential for groundwater abstraction seems to be huge. The key issues in this part of the study are the extent of the recharge area and the recharge rates. The direct recharge area has previously been considered to be the area of outcrop of Karoo Forest sandstone...... support this extension of the recharge area to include a large area below the fractured basalt. CO2 gas pressures, calculated with the code PHREEQC using field measurements of pH and alkalinity, show that below the fractured basalt the groundwater is an open system in contact with atmospheric CO2. The 14C...... and nitrate concentrations in this groundwater also indicate that recent infiltration takes place. The chloride contents of the rainfall and the groundwater in the recharge area have been measured to calculate direct recharge from rainfall. These data indicate that the direct recharge is in the range of 10...

  12. GROUNDWATER RECHARGE AND CHEMICAL ...

    Science.gov (United States)

    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

  13. Rechargeable Lithium Metal Cell Project

    Data.gov (United States)

    National Aeronautics and Space Administration — PSI proposes to develop a rechargeable lithium metal cell with energy density >400Wh/kg. This represents a >70% increase as compared to similarly constructed...

  14. Impact of artificial recharge on dissolved noble gases in groundwater in California.

    Science.gov (United States)

    Cey, Bradley D; Hudson, G Bryant; Moran, Jean E; Scanlon, Bridget R

    2008-02-15

    Dissolved noble gas concentrations in groundwater can provide valuable information on recharge temperatures and enable 3H-3He age-dating with the use of physically based interpretive models. This study presents a large (905 samples) data set of dissolved noble gas concentrations from drinking water supply wells throughout California, representing a range of physiographic, climatic, and water management conditions. Three common interpretive models (unfractionated air, UA; partial re-equilibration, PR; and closed system equilibrium, CE) produce systematically different recharge temperatures or ages; however, the ability of the different models to fit measured data within measurement uncertainty indicates that goodness-of-fit is not a robust indicator for model appropriateness. Therefore caution is necessary when interpreting model results. Samples from multiple locations contained significantly higher Ne and excess air concentrations than reported in the literature, with maximum excess air tending toward 0.05 cm3 STP g(-1) (deltaNe approximately 400%). Artificial recharge is the most plausible cause of the high excess air concentrations. The ability of artificial recharge to dissolve greater amounts of atmospheric gases has important implications for oxidation-reduction dependent chemical reactions. Measured gas concentration ratios suggest that diffusive degassing may have occurred. Understanding the physical processes controlling gas dissolution during groundwater recharge is critical for optimal management of artificial recharge and for predicting changes in water quality that can occur following artificial recharge.

  15. Characteristics of Point Recharge in Karst Aquifers

    OpenAIRE

    Somaratne, Nara

    2014-01-01

    Karstic groundwater basins are characterized by both point and diffuse recharge. This paper describes the hydrologic characteristics of point recharge and their influence on recharge estimation for four groundwater basins. Point recharge is highly transient and may occur in relatively short-time periods, yet is capable of recharging a large volume of water, even from a single extreme rainfall event. Preferential groundwater flows are observed in karst aquifers with local fresher water pockets...

  16. Functional materials for rechargeable batteries.

    Science.gov (United States)

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

    2011-04-19

    There is an ever-growing demand for rechargeable batteries with reversible and efficient electrochemical energy storage and conversion. Rechargeable batteries cover applications in many fields, which include portable electronic consumer devices, electric vehicles, and large-scale electricity storage in smart or intelligent grids. The performance of rechargeable batteries depends essentially on the thermodynamics and kinetics of the electrochemical reactions involved in the components (i.e., the anode, cathode, electrolyte, and separator) of the cells. During the past decade, extensive efforts have been dedicated to developing advanced batteries with large capacity, high energy and power density, high safety, long cycle life, fast response, and low cost. Here, recent progress in functional materials applied in the currently prevailing rechargeable lithium-ion, nickel-metal hydride, lead acid, vanadium redox flow, and sodium-sulfur batteries is reviewed. The focus is on research activities toward the ionic, atomic, or molecular diffusion and transport; electron transfer; surface/interface structure optimization; the regulation of the electrochemical reactions; and the key materials and devices for rechargeable batteries. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Characteristics of Point Recharge in Karst Aquifers

    Directory of Open Access Journals (Sweden)

    Nara Somaratne

    2014-09-01

    Full Text Available Karstic groundwater basins are characterized by both point and diffuse recharge. This paper describes the hydrologic characteristics of point recharge and their influence on recharge estimation for four groundwater basins. Point recharge is highly transient and may occur in relatively short-time periods, yet is capable of recharging a large volume of water, even from a single extreme rainfall event. Preferential groundwater flows are observed in karst aquifers with local fresher water pockets of low salinity that develop around point recharge sources. Measurable fresh water plumes develop only when a large quantity of surface water enters the aquifer as a point recharge. In fresh water plumes, the difference in chloride concentrations in diffuse and point recharge zones decreases as the plumes become enriched through mixing. The relative contributions to total recharge from point sources using the measured gap between groundwater and rainwater chloride in the chloride vs. δ18O plot is not necessarily indicative of sinkholes not directly recharging the aquifer. In karst aquifers, recharge estimation methods based on groundwater age distribution; average annual rainfall and basin average chloride in the conventional chloride mass balance (CMB method are questionable due to theoretical limitations and key assumptions of these methods not being met. In point recharge dominant groundwater basins, application of: watertable fluctuation, numerical groundwater modelling, Darcy flow calculation or water budget methods are more suitable for recharge estimation as they are independent of the particular mode of recharge. The duality of the recharge mechanism in karst aquifers suggests that modification to the CMB method may be required to include both point and diffuse recharge components.

  18. Artificial recharge of surface water to aquifer

    OpenAIRE

    Čechová, Tereza

    2014-01-01

    Artificial recharge of surface water to aquifer Tereza Čechová, Geotechnologie Abstract: The bachelor thesis is devoted to groundwater recharge. The source of groundwater is infiltration of atmospheric precipitation. The study deals with the use of controlled artificial recharge in the Czech Republic and the other countries in the Word.

  19. Trench infiltration for managed aquifer recharge to permeable bedrock

    Science.gov (United States)

    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.

  20. Rechargeable Aluminum-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-01

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

  1. Survey of rechargeable battery technology

    Energy Technology Data Exchange (ETDEWEB)

    1993-07-01

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

  2. Iron-Air Rechargeable Battery

    Science.gov (United States)

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

    2014-01-01

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

  3. Electrode materials for rechargeable battery

    Science.gov (United States)

    Johnson, Christopher; Kang, Sun-Ho

    2015-09-08

    A positive electrode is disclosed for a non-aqueous electrolyte lithium rechargeable cell or battery. The electrode comprises a lithium containing material of the formula Na.sub.yLi.sub.xNi.sub.zMn.sub.1-z-z'M.sub.z'O.sub.d, wherein M is a metal cation, x+y>1, 0replace sodium ions of a precursor material with lithium ions.

  4. Groundwater recharge and agricultural contamination

    Science.gov (United States)

    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.

  5. Rechargeable lithium battery technology - A survey

    Science.gov (United States)

    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.

  6. Metal Hydrides for Rechargeable Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Valoeen, Lars Ole

    2000-03-01

    Rechargeable battery systems are paramount in the power supply of modern electronic and electromechanical equipment. For the time being, the most promising secondary battery systems for the future are the lithium-ion and the nickel metal hydride (NiMH) batteries. In this thesis, metal hydrides and their properties are described with the aim of characterizing and improving those. The thesis has a special focus on the AB{sub 5} type hydrogen storage alloys, where A is a rare earth metal like lanthanum, or more commonly misch metal, which is a mixture of rare earth metals, mainly lanthanum, cerium, neodymium and praseodymium. B is a transition metal, mainly nickel, commonly with additions of aluminium, cobalt, and manganese. The misch metal composition was found to be very important for the geometry of the unit cell in AB{sub 5} type alloys, and consequently the equilibrium pressure of hydrogen in these types of alloys. The A site substitution of lanthanum by misch metal did not decrease the surface catalytic properties of AB{sub 5} type alloys. B-site substitution of nickel with other transition elements, however, substantially reduced the catalytic activity of the alloy. If the internal pressure within the electrochemical test cell was increased using inert argon gas, a considerable increase in the high rate charge/discharge performance of LaNi{sub 5} was observed. An increased internal pressure would enable the utilisation of alloys with a high hydrogen equivalent pressure in batteries. Such alloys often have favourable kinetics and high hydrogen diffusion rates and thus have a potential for improving the high current discharge rates in metal hydride batteries. The kinetic properties of metal hydride electrodes were found to improve throughout their lifetime. The activation properties were found highly dependent on the charge/discharge current. Fewer charge/discharge cycles were needed to activate the electrodes if a small current was used instead of a higher

  7. Quantification of groundwater recharge in urban environments.

    Science.gov (United States)

    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.

  8. Automating Recession Curve Displacement Recharge Estimation.

    Science.gov (United States)

    Smith, Brennan; Schwartz, Stuart

    2017-01-01

    Recharge estimation is an important and challenging element of groundwater management and resource sustainability. Many recharge estimation methods have been developed with varying data requirements, applicable to different spatial and temporal scales. The variability and inherent uncertainty in recharge estimation motivates the recommended use of multiple methods to estimate and bound regional recharge estimates. Despite the inherent limitations of using daily gauged streamflow, recession curve displacement methods provide a convenient first-order estimate as part of a multimethod hierarchical approach to estimate watershed-scale annual recharge. The implementation of recession curve displacement recharge estimation in the United States Geologic Survey (USGS) RORA program relies on the subjective, operator-specific selection of baseflow recession events to estimate a gauge-specific recession index. This paper presents a parametric algorithm that objectively automates this tedious, subjective process, parameterizing and automating the implementation of recession curve displacement. Results using the algorithm reproduce regional estimates of groundwater recharge from the USGS Appalachian Valley and Piedmont Regional Aquifer-System Analysis, with an average absolute error of less than 2%. The algorithm facilitates consistent, completely automated estimation of annual recharge that complements more rigorous data-intensive techniques for recharge estimation. © 2016, National Ground Water Association.

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

    Science.gov (United States)

    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.

  10. Groundwater recharge in different physiognomies of the Brazilian Cerrado

    Science.gov (United States)

    Oliveira, P. T. S.; Leite, M.; Mattos, T.; Wendland, E.; Nearing, M. A.

    2015-12-01

    Since 2014, several cities of southeastern Brazil have grappled with their worst drought in nearly 80 years. To improve water availability in this region, the Brazilian government has studied the possibility of increasing groundwater use, mainly in the Guarani Aquifer System (GAS), the largest (~1.2 million km2) transnational boundary groundwater reservoir in South America. Approximately one half of the outcrop areas of the GAS are located in the Cerrado biome, the main agricultural expansion region in Brazil. Large areas of Cerrado vegetation have been converted into farmland in recent years; however, little attention has been paid to the consequences of this land cover and land use change on groundwater recharge. In this study we assessed groundwater recharge in different physiognomies of the Cerrado located in an outcrop area of the GAS. Water table fluctuations were measured from October 2011 through August 2013, by 64 monitoring wells distributed on five physiognomies of the undisturbed Cerrado. We used 20 (2.2±0.3 m), 20 (4.3±1.4 m), 14 (4.7±1.9 m), 9 (6.2±0.7 m), and 1 (42 m) monitoring wells (and average depth of wells) for "campo limpo" (cerrado grassland), "campo sujo" (shrub cerrado), "campo cerrado" (shrub cerrado), "cerrado sensu stricto" (wooded cerrado), and "cerrado sensu stricto denso" (cerrado woodland), respectively. Recharge was computed for each well using the Water Table Fluctuation method. The measured precipitation for hydrological years 2011-12 and 2012-13 were 1247 mm and 1194 mm, respectively. We found values of average annual recharge of 363 mm, 354 mm, 324 mm, and 315 mm for "campo limpo", "campo sujo","campo cerrado", and "cerrado sensu stricto", respectively. We did not find changes in the water table level in the one well located in the "cerrado sensu stricto denso". The water table in this well was 35 m deep; therefore, the amount of water that eventually reached the saturated zone was not enough to cause a rapid change in the

  11. Comparative analysis of groundwater recharge estimation Value ...

    African Journals Online (AJOL)

    Estimation of natural groundwater recharge is a pre-requisite for efficient groundwater resource management especially in regions with large demands for groundwater supplies, where such resources are the key to economic development. Groundwater recharge, by whatever method, is normally subjected to large ...

  12. Groundwater recharge using baseflow recession analysis in ...

    African Journals Online (AJOL)

    Baseflow recession analyses of Yewa and Ona rivers were carried out with a view to determining and comparing groundwater recharge in parts of the sedimentary and Basement Complex terrains of Southwestern Nigeria. Daily discharges of the rivers for ten years (1988 – 1997) were analysed. Groundwater recharge in ...

  13. Application and comparison of groundwater recharge estimation ...

    African Journals Online (AJOL)

    Then Bima Sandstone aquifer is the main water resource in the semi-arid Yola area of Northeastern, Nigeria. The rapid increase in water demand in this area has prompted the need to estimate available groundwater recharge for sustainable utilization. Groundwater recharge estimation methods and results are compared: ...

  14. A rechargeable carbon-oxygen battery

    DEFF Research Database (Denmark)

    2014-01-01

    The invention relates to a rechargeable battery and a method to operate a rechargeable battery having high efficiency and high energy density for storing energy. The battery stores electrical energy in the bonds of carbon and oxygen atoms by converting carbon dioxide into solid carbon and oxygen....

  15. Studies on groundwater recharge through surface drains

    African Journals Online (AJOL)

    2005-04-02

    Apr 2, 2005 ... to change in the value of specific yield than hydraulic conductivity. Keywords: finite difference model, groundwater recharge, surface drain, water table. List of symbols a. = area of cross-section of flow at any z ..... avg. wt = Q(t)/(2L*drl). (23). Figure 2. Flow chart of the groundwater recharge model for surface.

  16. Identifying and quantifying urban recharge: a review

    Science.gov (United States)

    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.

  17. Delineating Recharge Elevation and Constraining Residence Time of Groundwater on Mount Shasta

    Science.gov (United States)

    Moran, J. E.; Peters, E.; Visser, A.; Esser, B. K.; Singleton, M. J.

    2016-12-01

    A warming climate will bring drastic changes to hydrologic systems in the headwater basins of the major rivers in California. Runoff in these rivers fills the reservoirs that sustain cities and agriculture through the dry months, while cool, late season groundwater discharge to streams is critical for sustaining subalpine ecosystems. Despite the important role they play in the larger hydrologic system, groundwater flow paths in headwater basins are typically not well characterized, with recharge and discharge locations largely unidentified, and subsurface residence times unknown. We examined several groundwater residence time tracers, stable isotopes and noble gas recharge temperatures in samples from wells and springs on Mount Shasta at the headwaters of the Sacramento River. The topographic relief in the study area imparts robust signatures of recharge elevation to both stable isotopes of the water molecule (δ18O and δD), and to dissolved noble gases, offering tools to identify recharge areas and delineate groundwater flow paths. This study was carried out during drought years, when the influence of runoff and recent recharge were minimal. Recharge elevations determined using stable isotopes and noble gas recharge temperatures are in close agreement, and indicate that most snowmelt infiltrates at elevations between 2000 and 2900 m (6600 and 9500 ft), which coincides with areas of thin soils and barren land cover. The large springs in Mt Shasta City discharge at an elevation more than 1500 m lower. High elevation springs (>2000 m) yield very young water (water with a residence time of 6 years or more, based on tritium concentrations in sampled water. Residence time indicators with shorter half-lives (35-Sulfur and 22-Sodium) were not detected, suggesting that very recent recharge was a negligibly small component at the time of sampling. Combined with recharge elevation estimates, ages indicate horizontal flow velocities between 0.5 and 1 km per year. Differences

  18. Effect of in situ pyrolysis of acetylene (C2H2) gas as a carbon source on the electrochemical performance of LiFePO4 for rechargeable lithium-ion batteries

    Science.gov (United States)

    Saroha, Rakesh; Panwar, Amrish K.

    2017-06-01

    The intention of this work is to study the effect of in situ pyrolysis of acetylene (C2H2) gas used as a carbon source on the physicochemical and electrochemical performance of pristine LiFePO4 (LFP). Acetylene gas, which decomposed to carbon and methane along with some side products when exposed to high temperature (>625 °C), is used as a carbon source for coating over the surface of LFP particles. Thermogravimetric (TGA) measurements were performed in an air atmosphere, primarily to estimate the exact amount of carbon deposited on the surface of the olivine cathode material due to the decomposition of C2H2 gas. Raman and TGA results confirm the presence of carbon as coated on the surface of the prepared compositions. Among all the synthesized samples, LFP with 10 min C2H2 treatment (LFPC10) shows the highest discharge capacity at all C-rates and exhibits excellent rate performance. LFPC10 delivers a specific discharge capacity of 144 (±5) mAh g-1 (~85% of the theoretical capacity of 170 mAh g-1) at 0.1C rate. LFPC10 demonstrates the best cycling performance as it offers an initial discharge capacity of about 117 (±5) mAh g-1 (~69% of the theoretical capacity) at 1C-rate and has 97% capacity retention even after 100 charge/discharge cycles.

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

    Science.gov (United States)

    Sophocleous, M.

    1992-01-01

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

  20. High Temperature Rechargeable Battery Development Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This small business innovation research is intended to develop and proof the concept of a highly efficient, high temperature rechargeable battery for supporting...

  1. Electrode materials for rechargeable battery

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Christopher; Kang, Sun-Ho

    2015-09-08

    A positive electrode is disclosed for a non-aqueous electrolyte lithium rechargeable cell or battery. The electrode comprises a lithium containing material of the formula Na.sub.yLi.sub.xNi.sub.zMn.sub.1-z-z'M.sub.z'O.sub.d, wherein M is a metal cation, x+y>1, 0

  2. Economics of Managed Aquifer Recharge

    Directory of Open Access Journals (Sweden)

    Robert G. Maliva

    2014-05-01

    Full Text Available Managed aquifer recharge (MAR technologies can provide a variety of water resources management benefits by increasing the volume of stored water and improving water quality through natural aquifer treatment processes. Implementation of MAR is often hampered by the absence of a clear economic case for the investment to construct and operate the systems. Economic feasibility can be evaluated using cost benefit analysis (CBA, with the challenge of monetizing benefits. The value of water stored or treated by MAR systems can be evaluated by direct and indirect measures of willingness to pay including market price, alternative cost, value marginal product, damage cost avoided, and contingent value methods. CBAs need to incorporate potential risks and uncertainties, such as failure to meet performance objectives. MAR projects involving high value uses, such as potable supply, tend to be economically feasible provided that local hydrogeologic conditions are favorable. They need to have low construction and operational costs for lesser value uses, such as some irrigation. Such systems should therefore be financed by project beneficiaries, but dichotomies may exist between beneficiaries and payers. Hence, MAR projects in developing countries may be economically viable, but external support is often required because of limited local financial resources.

  3. Spatial variability of groundwater recharge - I. Is it really variable?

    OpenAIRE

    De Silva, RP

    2004-01-01

    The spatial variability of recharge is an important consideration in estimating recharge especially as all methods of estimating it are 'point' estimates and in most places recharge varies in space. This paper along with the accompanying paper attempts to find a suitable answer to the question of taking this variability into account in estimating groundwater recharge. This paper attempts to determine if recharge is actually varying in space and that this is 'true' variability and that it is n...

  4. The character of organic carbon in recharge water and arsenic mobilization in Bangladesh aquifers

    Science.gov (United States)

    Pracht, L. E.; Fussell, A. H.; Polizzotto, M.; Badruzzaman, A. M.; Ali, M. A.; Neumann, R. B.

    2012-12-01

    In Bangladesh, arsenic-contaminated groundwater, used for both drinking and irrigation supplies, negatively affects the health of millions of people. Past work at our site in Munshiganj suggests that current patterns of arsenic concentration in the aquifer are related to groundwater flow and recharge chemistry. Constructed ponds and groundwater-irrigated rice fields serve as the primary aquifer recharge sources, with pond recharge evolving into high-arsenic groundwater and rice field recharge evolving into low-arsenic groundwater. The composition of these water types vary in concentrations and character of dissolved organic carbon, a presumed key component in the mechanism of arsenic release from sediments. Here we present results from an experiment-based laboratory study that directly tests the role of organic carbon character and bioavailability on arsenic mobilization. Incubation experiments using sediment samples collected from Bangladesh and waters with different carbon sources (e.g., pond and rice field recharge water and artificial water with model carbon compounds) were conducted to show the phase transformations carbon undergoes during arsenic mobilization processes, to isolate the carbon components and characteristics most responsible for mobilization reactions, and to investigate the importance of secondary chemical constituents for completion of these physiochemical reactions. Water, gas, and sediment samples collected from the incubations were analyzed for nutrient, metal, anion, and carbon concentrations, as well as carbon character. The results clarify the chemical components most critical in arsenic mobilization and provide insight into the in situ chemical reactions occurring in the aquifer. Moreover, this better chemical understanding helps elucidate the potential impact of altered recharge patterns and recharge chemistry on arsenic concentrations of Bangladeshi groundwater supplies.

  5. Theory of the generalized chloride mass balance method for recharge estimation in groundwater basins characterised by point and diffuse recharge

    OpenAIRE

    N. Somaratne; K. R. J. Smettem

    2014-01-01

    Application of the conventional chloride mass balance (CMB) method to point recharge dominant groundwater basins can substantially under-estimate long-term average annual recharge by not accounting for the effects of localized surface water inputs. This is because the conventional CMB method ignores the duality of infiltration and recharge found in karstic systems, where point recharge can be a contributing factor. When point recharge is present in groundwater basins,...

  6. Using groundwater levels to estimate recharge

    Science.gov (United States)

    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.

  7. Lab-size rechargeable metal hydride-air cells

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Wei-Kang; Noreus, Dag [Department of Materials and Enviromental Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm (Sweden)

    2010-09-01

    Lab-size rechargeable metal hydride-air (MH-air) cells with a gas management device were designed in order to minimize the loss of electrolyte. An AB{sub 5}-type hydrogen storage alloy was used as anode materials of the MH-air. The thickness of the metal hydride electrodes was in the range of 3.0-3.4 mm. Porous carbon-based air electrodes with Ag{sub 2}O catalysts were used as bi-functional electrodes for oxygen reduction and generation. The electrodes were first examined in half-cells to evaluate their performance and then assembled into one MH-air cell. The results showed the good cycling stability of the rechargeable MH-air cell with a capacity of 1990 mAh. The discharge voltage was 0.69 V at 0.05-0.1 C. The charge efficiency was about 90%. The specific and volumetric energy densities were about 95Wh kg{sup -1} and 140 Wh L{sup -1}, respectively. (author)

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

    Science.gov (United States)

    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.

  9. Global-scale modeling of groundwater recharge

    Science.gov (United States)

    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

  10. Global-scale modeling of groundwater recharge

    Science.gov (United States)

    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

  11. Rechargeable batteries materials, technologies and new trends

    CERN Document Server

    Zhang, Zhengcheng

    2015-01-01

    This book updates the latest advancements in new chemistries, novel materials and system integration of rechargeable batteries, including lithium-ion batteries and batteries beyond lithium-ion and addresses where the research is advancing in the near future in a brief and concise manner. The book is intended for a wide range of readers from undergraduates, postgraduates to senior scientists and engineers. In order to update the latest status of rechargeable batteries and predict near research trend, we plan to invite the world leading researchers who are presently working in the field to write

  12. Global-scale modeling of groundwater recharge

    Directory of Open Access Journals (Sweden)

    P. Döll

    2008-05-01

    Full Text Available 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

  13. 77 FR 2437 - Special Conditions: Gulfstream Aerospace Corporation, Model GVI Airplane; Rechargeable Lithium...

    Science.gov (United States)

    2012-01-18

    ...; Rechargeable Lithium Batteries and Rechargeable Lithium- Battery Systems AGENCY: Federal Aviation... have a novel or unusual design feature associated with the installation of rechargeable lithium batteries and rechargeable lithium-battery systems. The applicable airworthiness regulations do not contain...

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

    Science.gov (United States)

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

    2014-01-01

    Groundwater recharge is an important component of the groundwater system. On the North China Plain (NCP), groundwater is the main water supply. Because of large-scale overexploitation, the water table has declined, which has produced severe adverse effects on the environment and ecosystem. In this article, tracer experiment and watershed model were used to calculate and analyze NCP groundwater recharge. In the tracer experiment, average recharge was 108 mm/year and recharge coefficient 0.16. With its improved irrigation, vegetation coverage and evapotranspiration modules, the INFIL3.0 model was used for calculation of groundwater recharge. Regional modeling results showed an average recharge of 102 mm/year and recharge coefficient 0.14, for 2001-2009. These values are very similar to those from the field tracer experiment. Influences in the two methods were analyzed. The results can provide an important reference for NCP groundwater recharge. © 2013, National Ground Water Association.

  15. Estimating Monetized Benefits of Groundwater Recharge from Stormwater Retention Practices

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  17. Assessment of Natural Groundwater Recharge in Terengganu, Malaysia

    OpenAIRE

    Abdullahi, Musa Garba; Kamarudin, Mohd Khairul Amri; Toriman, Mohd Ekhwan; Gasim, Muhammad Barzani; Endut, Azizah; Garba, Iliyasu

    2016-01-01

    Estimation of groundwater recharge is essential for efficient groundwater resources management, for domestic uses and irrigation purposes in the study area. The present research entails the assessment of natural groundwater recharge in Terengganu Malaysia. Estimation of recharge by whatever method is usually subjected to a large uncertaintyand errors. However, this research attempt to derive an empirical relationship to determine the groundwater recharge from rainfall based on seasonal ground...

  18. Soil moisture data as a constraint for groundwater recharge estimation.

    OpenAIRE

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

    2017-01-01

    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 mea...

  19. Aquifer Recharge Estimation through Atmospheric Chloride Mass Balance at Las Cañadas Caldera, Tenerife, Canary Islands, Spain

    Directory of Open Access Journals (Sweden)

    Rayco Marrero-Diaz

    2015-05-01

    Full Text Available The atmospheric chloride mass balance (CMB method was used to estimate net aquifer recharge in Las Cañadas Caldera, an endorheic summit aquifer area about 2000 m a.s.l. with negligible surface runoff, which hosts the largest freshwater reserve in Tenerife Island, Canary Islands, Spain. The wet hydrological year 2005–2006 was selected to compare yearly atmospheric chloride bulk deposition and average chloride content in recharge water just above the water table, both deduced from periodical sampling. The potential contribution of chloride to groundwater from endogenous HCl gas may invalidate the CMB method. The chloride-to-bromide molar ratio was an efficient tracer used to select recharge water samples having atmospheric origin of chloride. Yearly net aquifer recharge was 631 mm year−1, i.e., 69% of yearly precipitation. This result is in agreement with potential aquifer recharge estimated through an independent lumped-parameter rainfall-runoff model operated by the Insular Water Council of Tenerife. This paper illustrates basic procedures and routines to use the CMB method for aquifer recharge in active volcanic oceanic islands having sparse-data coverage and groundwater receiving contribution of endogenous halides.

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

    Directory of Open Access Journals (Sweden)

    H. Hashemi

    2013-02-01

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

  1. 30 CFR 56.4203 - Extinguisher recharging or replacement.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Extinguisher recharging or replacement. 56.4203... Prevention and Control Firefighting Equipment § 56.4203 Extinguisher recharging or replacement. Fire extinguishers shall be recharged or replaced with a fully charged extinguisher promptly after any discharge. ...

  2. 30 CFR 57.4203 - Extinguisher recharging or replacement.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Extinguisher recharging or replacement. 57.4203... Prevention and Control Firefighting Equipment § 57.4203 Extinguisher recharging or replacement. Fire extinguishers shall be recharged or replaced with a fully charged extinguisher promptly after any discharge. ...

  3. Alloys of clathrate allotropes for rechargeable batteries

    Science.gov (United States)

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

    2014-12-09

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

  4. Rechargeable solid polymer electrolyte battery cell

    Science.gov (United States)

    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.

  5. Groundwater Recharge, Evapotranspiration and Surface Runoff ...

    African Journals Online (AJOL)

    Groundwater Recharge, Evapotranspiration and Surface Runoff Estimation Using WetSpass Modeling Method in Illala Catchment, Northern Ethiopia. ... Abstract. Hydrometeorological information is important in planning and management of natural resources. The northern Ethiopia in general and Illala sub-basin in particular ...

  6. Anodes for Rechargeable Lithium-Sulfur Batteries

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-10

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

  7. Groundwater Recharge, Evapotranspiration and Surface Runoff ...

    African Journals Online (AJOL)

    Bheema

    this unit at different parts of the catchment. Hence, in the ... decrease currently due to different soil and water conservation practices conducted especially in .... water body. Actual evapotranspiration is one components of water balance to determine groundwater recharge of Illala catchment using the WetSpass model.

  8. Recharging Our Sense of Idealism: Concluding Thoughts

    Science.gov (United States)

    D'Andrea, Michael; Dollarhide, Colette T.

    2011-01-01

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

  9. application and comparison of groundwater recharge estimation ...

    African Journals Online (AJOL)

    DJFLEX

    storage studies and their application to the determination of infiltration. Trans Am. Geopys. Union 19:435-445. Larsen F, Owen R, Dahlin T, and Mangeya, P., 2002. A preliminary analysis of the groundwater recharge to the Karoo Formations, ...

  10. An approach to identify urban groundwater recharge

    Directory of Open Access Journals (Sweden)

    E. Vázquez-Suñé

    2010-10-01

    Full Text Available Evaluating the proportion in which waters from different origins are mixed in a given water sample is relevant for many hydrogeological problems, such as quantifying total recharge, assessing groundwater pollution risks, or managing water resources. Our work is motivated by urban hydrogeology, where waters with different chemical signature can be identified (losses from water supply and sewage networks, infiltration from surface runoff and other water bodies, lateral aquifers inflows, .... The relative contribution of different sources to total recharge can be quantified by means of solute mass balances, but application is hindered by the large number of potential origins. Hence, the need to incorporate data from a large number of conservative species, the uncertainty in sources concentrations and measurement errors. We present a methodology to compute mixing ratios and end-members composition, which consists of (i Identification of potential recharge sources, (ii Selection of tracers, (iii Characterization of the hydrochemical composition of potential recharge sources and mixed water samples, and (iv Computation of mixing ratios and reevaluation of end-members. The analysis performed in a data set from samples of the Barcelona city aquifers suggests that the main contributors to total recharge are the water supply network losses (22%, the sewage network losses (30%, rainfall, concentrated in the non-urbanized areas (17%, from runoff infiltration (20%, and the Besòs River (11%. Regarding species, halogens (chloride, fluoride and bromide, sulfate, total nitrogen, and stable isotopes (18O, 2H, and 34S behaved quite conservatively. Boron, residual alkalinity, EDTA and Zn did not. Yet, including these species in the computations did not affect significantly the proportion estimations.

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

    Science.gov (United States)

    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

  12. Gas chemistry and thermometry of the Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Nehring, N.L. (US Geological Survey, Menlo Park, CA); D' Amore, F.

    1981-01-01

    Geothermal gases at Cerro Prieto are derived from high temperature reactions within the reservoir or are introduced with recharge water. Gases collected from geothermal wells should, therefore, reflect reservoir conditions. Interpretation of gas compositions of wells indicates reservoir temperatures, controls of oxygen and sulfur fugacities, and recharge source and direction.

  13. Anode-Free Rechargeable Lithium Metal Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Jiangfeng [The Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99354 USA; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Adams, Brian D. [The Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99354 USA; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Zheng, Jianming [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Xu, Wu [The Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99354 USA; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Henderson, Wesley A. [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Wang, Jun [A123 Systems Research and Development, Waltham MA 02451 USA; Bowden, Mark E. [Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland WA 99354 USA; Xu, Suochang [Earth and Biological Science Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Hu, Jianzhi [The Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99354 USA; Earth and Biological Science Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Zhang, Ji-Guang [The Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99354 USA; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA

    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 which minimize the corrosion of the in-situ formed Li metal anode.

  14. The rechargeable aluminum-ion battery

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-01

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

  15. The rechargeable aluminum-ion battery

    KAUST Repository

    Jayaprakash, N.

    2011-01-01

    We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl3 in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V2O5 nano-wire cathode against an aluminium metal anode. The battery delivered a discharge capacity of 305 mAh g-1 in the first cycle and 273 mAh g-1 after 20 cycles, with very stable electrochemical behaviour. © The Royal Society of Chemistry 2011.

  16. Recharge pattern of contemporary glass ionomer restoratives

    Directory of Open Access Journals (Sweden)

    Farahnaz Arbabzadeh-Zavareh

    2012-01-01

    Full Text Available Background: As glass ionomers have the ability to reload fluoride from outside sources, the aim was to compare the recharge pattern of six glass ionomer cements after exposure to fluoride. Materials and Methods: Fuji VII, Fuji IX, Riva Pink, Riva Bleach, Ketac Fil and Fuji IX Extra were investigated. The fluoride-containing materials used were tooth paste and mouth wash (Colgate. Specimens of each material (n=15 were immersed separately in deionized water for 59 days. Then the samples of each material were divided into three groups of five each. Two groups were recharged for 2, 20 and 60 min daily during three consecutive weekly intervals and then no treatment for one week. The third group was used as control. Fluoride release measurements (μg/cm 2 /day were made in every 24 h. One-way and repeated measures analysis of variance tests were used. Results: Tooth paste recharged materials showed higher level of recharge. On day 1, the difference of fluoride release from different treatment groups of different materials except for Fuji IX Extra were not significant (P>0.05. On days 7 and 14, the differences observed were significant (P<0.05 for all materials except for Fuji VII (tooth paste versus mouth wash and Trial Fuji IX (mouth wash versus control and on day 14 for Rvia Pink (mouth wash versus control. On days 21 and 28, the differences observed were significant for all the materials (P<0.05 except for Riva Pink (toothpaste versus mouth wash, Riva Bleach, Ketac Fil and Trial FujiI X (mouth wash versus control on day 28. Conclusion: A time tabled schedule of application of fluoride-containing materials could help to achieve high fluoride release.

  17. Nanomaterials for lithium-ion rechargeable batteries.

    Science.gov (United States)

    Liu, Hua Kun; Wang, Guo Xiu; Guo, Zaiping; Wang, Jiazhao; Konstantinov, Kosta

    2006-01-01

    In lithium-ion batteries, nanocrystalline intermetallic alloys, nanosized composite materials, carbon nanotubes, and nanosized transition-metal oxides are all promising new anode materials, while nanosized LiCoO2, LiFePO4, LiMn2O4, and LiMn2O4 show higher capacity and better cycle life as cathode materials than their usual larger-particle equivalents. The addition of nanosized metal-oxide powders to polymer electrolyte improves the performance of the polymer electrolyte for all solid-state lithium rechargeable batteries. To meet the challenge of global warming, a new generation of lithium rechargeable batteries with excellent safety, reliability, and cycling life is needed, i.e., not only for applications in consumer electronics, but especially for clean energy storage and for use in hybrid electric vehicles and aerospace. Nanomaterials and nanotechnologies can lead to a new generation of lithium secondary batteries. The aim of this paper is to review the recent developments on nanomaterials and nanotechniques used for anode, cathode, and electrolyte materials, the impact of nanomaterials on the performance of lithium batteries, and the modes of action of the nanomaterials in lithium rechargeable batteries.

  18. Simplicity versus complexity in modelling groundwater recharge in Chalk catchments

    Directory of Open Access Journals (Sweden)

    R. B. Bradford

    2002-01-01

    Full Text Available Models of varying complexity are available to provide estimates of recharge in headwater Chalk catchments. Some measure of how estimates vary between different models can help guide the choice of model for a particular application. This paper compares recharge estimates derived from four models employing input data at varying spatial resolutions for a Chalk headwater catchment (River Pang, UK over a four-year period (1992-1995 that includes a range of climatic conditions. One model was validated against river flow data to provide a measure of their relative performance. Each model gave similar total recharge for the crucial winter recharge period when evaporation is low. However, the simple models produced relatively lower estimates of the summer and early autumn recharge due to the way in which processes governing recharge especially evaporation and infiltration are represented. The relative uniformity of land use, soil types and rainfall across headwater, drift-free Chalk catchments suggests that complex, distributed models offer limited benefits for recharge estimates at the catchment scale compared to simple models. Nonetheless, distributed models would be justified for studies where the pattern and amount of recharge need to be known in greater detail and to provide more reliable estimates of recharge during years with low rainfall. Keywords: Chalk, modelling, groundwater recharge

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

    Science.gov (United States)

    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.

  20. Application of GIS Based Tools for Groundwater Recharge and Evapotranspiration Estimation: Arc-Recharge and RIPGIS-NET

    Science.gov (United States)

    Ajami, H.; Hogan, J.; Maddock, T.; Meixner, T.

    2007-12-01

    Water managers are increasingly concerned about the potential impact of climate variability and change on groundwater resources. Climate impacts on groundwater resources are primarily determined by altering the amount of recharge and evapotranspiration (ET). Typically, groundwater models employ temporally static recharge or ET rates with limited spatial variability across the basin. As a result most groundwater models cannot be used to assess the impacts of climate on groundwater resources. A primary challenge addressing this shortcoming is the need for spatially and temporally explicit recharge and ET model inputs. Geographic Information Systems (GIS) and spatially explicit data can be applied to develop these improved model inputs by quantifying and distributing recharge and ET across the model domain. Two ArcGIS desktop applications were developed for ArcGIS 9.2 to enhance recharge and ET estimation- Arc- Recharge and RIPGIS-NET. Arc-Recharge an ArcGIS 9.2 custom application is developed to quantify and distribute recharge along MODFLOW cells. Using spatially explicit precipitation data and Digital Elevation Model (DEM), Arc-Recharge routes water through the landscape and distributes the recharge to the appropriate groundwater model cells. RIPGIS-NET is an ArcGIS custom application that was developed to provide parameters for the RIP-ET package. RIP-ET is an improved MODFLOW ET module that simulates ET using a set of eco-physiologically based ET curves. RIPGIS-NET improves alluvial recharge estimation by providing spatially explicit information about the riparian/wetland ET. Application of Arc-Recharge and RIPGIS-NET in groundwater modeling enhances recharge and ET estimation by incorporating temporally and spatially explicit data. Using such tools, assessment of climate variability on groundwater resources will be enhanced.

  1. Climatic controls on diffuse groundwater recharge across Australia

    Directory of Open Access Journals (Sweden)

    O. V. Barron

    2012-12-01

    Full Text Available Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modelling for a range of Köppen-Geiger climate types (tropical, arid and temperate to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate types, the correlation between the modelled recharge and total annual rainfall is weaker than the correlation between recharge and the annual rainfall parameters reflecting rainfall intensity. Under similar soil and vegetation conditions for the same annual rainfall, annual recharge in regions with winter-dominated rainfall is greater than in regions with summer-dominated rainfall. The importance of climate parameters other than rainfall in recharge estimation is highest in the tropical climate type. Mean annual values of solar radiation and vapour pressure deficit show a greater importance in recharge estimation than mean annual values of the daily mean temperature. Climate parameters have the lowest relative importance in recharge estimation in the arid climate type (with cold winters and the temperate climate type. For 75% of all soil, vegetation and climate types investigated, recharge elasticity varies between 2 and 4 indicating a 20% to 40% change in recharge for a 10% change in annual rainfall. Understanding how climate controls recharge under the observed historical climate allows more informed choices of analogue sites if they are to be used for climate change impact assessments.

  2. Climatic controls on diffuse groundwater recharge across Australia

    OpenAIRE

    O. V. Barron; R. S. Crosbie; Pollock, D.; W. R. Dawes; Charles, S. P.; Pickett, T.; M. Donn

    2012-01-01

    Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modeling for a range of Köppen-Geiger climate types (tropical, arid and temperate) to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate t...

  3. Climatic controls on diffuse groundwater recharge across Australia

    OpenAIRE

    O. V. Barron; R. S. Crosbie; W. R. Dawes; Charles, S. P.; Pickett, T.; Donn, M. J.

    2012-01-01

    Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modelling for a range of Köppen-Geiger climate types (tropical, arid and temperate) to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority ...

  4. Transient Recharge Estimability Through Field-Scale Groundwater Model Calibration.

    Science.gov (United States)

    Knowling, Matthew J; Werner, Adrian D

    2017-11-01

    The estimation of recharge through groundwater model calibration is hampered by the nonuniqueness of recharge and aquifer parameter values. It has been shown recently that the estimability of spatially distributed recharge through calibration of steady-state models for practical situations (i.e., real-world, field-scale aquifer settings) is limited by the need for excessive amounts of hydraulic-parameter and groundwater-level data. However, the extent to which temporal recharge variability can be informed through transient model calibration, which involves larger water-level datasets, but requires the additional consideration of storage parameters, is presently unknown for practical situations. In this study, time-varying recharge estimates, inferred through calibration of a field-scale highly parameterized groundwater model, are systematically investigated subject to changes in (1) the degree to which hydraulic parameters including hydraulic conductivity (K) and specific yield (S y ) are constrained, (2) the number of water-level calibration targets, and (3) the temporal resolution (up to monthly time steps) at which recharge is estimated. The analysis involves the use of a synthetic reality (a reference model) based on a groundwater model of Uley South Basin, South Australia. Identifiability statistics are used to evaluate the ability of recharge and hydraulic parameters to be estimated uniquely. Results show that reasonable estimates of monthly recharge (recharge root-mean-squared error) require a considerable amount of transient water-level data, and that the spatial distribution of K is known. Joint estimation of recharge, S y and K, however, precludes reasonable inference of recharge and hydraulic parameter values. We conclude that the estimation of temporal recharge variability through calibration may be impractical for real-world settings. © 2017, National Ground Water Association.

  5. Summary of groundwater-recharge estimates for Pennsylvania

    Science.gov (United States)

    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

  6. Startup Report for Ground Water Extraction, Treatment, and Recharge System

    National Research Council Canada - National Science Library

    Lamb, Steve

    1997-01-01

    The document presents startup procedures, observations and measurements conducted during the startup of the Groundwater Extraction, Treatment and Recharge System, built for the 162nd Fighter Wing, Air...

  7. Evolution of strategies for modern rechargeable batteries.

    Science.gov (United States)

    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

  8. Progress in rechargeable magnesium battery technology

    Energy Technology Data Exchange (ETDEWEB)

    Suresh, G.S.; Levi, E.; Mitelman, A.; Mizrahi, O.; Chusid, O. [Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900 (Israel); Brunelli, M. [ESRF, Rue Jules Horowitz, BP 200, 38043 Grenoble Cedex (France); Aurbach, D.

    2007-12-03

    A new generation of rechargeable magnesium batteries with improved performance is presented. The cathodes are Chevrel phases of the Mo{sub 6}S{sub 8-y}Se{sub y} (y =0, 1, 2) type. The partial substitution of S by Se in these materials enables a very fast and reversible Mg intercalation at capacities close to the theoretical values, due to structural changes in the Mg insertion sites and increase in the polarizability of the anionic framework of the host. New electrolyte solutions with electrochemical windows wider than 3 V are also briefly reported. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

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

    Science.gov (United States)

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

    2016-04-01

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

  10. The effect of repeated fluoride recharge and storage media on bond durability of fluoride rechargeable Giomer bonding agent.

    Science.gov (United States)

    Naoum, S; O'Regan, J; Ellakwa, A; Benkhart, R; Swain, M; Martin, E

    2012-06-01

    For a restorative material or adhesive to exhibit caries inhibitive potential through fluoride release, it must be capable of fluoride recharge. The aim of this study was to evaluate the effect of repeated fluoride recharge and different storage media on dentine bond strength durability. Two self-etch adhesive systems (two-step) were evaluated: fluoride-rechargeable Giomer FL-Bond II and non-fluoride-containing UniFil Bond. For each adhesive 32 human dentine specimens were prepared for shear bond strength testing. The specimens were randomly allocated to one of four storage groups: Group 1 - 24-hour water ageing; Group 2 - four-month water ageing; Group 3 - four-month water ageing with weekly fluoride recharge (5000 ppm for 10 minutes); and Group 4 - four-month acid ageing with weekly fluoride recharge. Weekly fluoride recharge over four months ageing did not significantly (p > 0.05) reduce the dentine shear bond strength of FL-Bond II or UniFil Bond. Storage media did not significantly (p > 0.05) affect bond durability. The adhesion between fluoride rechargeable FL-Bond II and dentine maintained durability despite regular fluoride recharge over the four months ageing. Clinicians prescribing the fluoride recharge regime used in the present study to reduce recurrent caries incidence associated with Giomer FL-Bond II restorations can do so without compromising dentine bond strengths. © 2012 Australian Dental Association.

  11. Challenges of Artificial Recharge at the Chain of Lakes

    Science.gov (United States)

    Zeng, X.

    2004-12-01

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

  12. Alterations to groundwater recharge due to anthropogenic landscape change

    Science.gov (United States)

    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.

  13. Soil moisture data as a constraint for groundwater recharge estimation

    Science.gov (United States)

    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.

  14. Comparing groundwater recharge and base flow in the Bukmoongol ...

    Indian Academy of Sciences (India)

    Groundwater recharge and base flow using different investigated methods are simulated in the 15-ha Bukmoongol small-forested watershed located at the southern part of Korea.The WHAT system, PART,RORA,PULSE,BFI,and RAP software are used to estimate groundwater recharge or base flow and base flow index from ...

  15. Artificial Recharge via Boreholes Using Treated Wastewater: Possibilities and Prospects

    Directory of Open Access Journals (Sweden)

    Kostas Voudouris

    2011-09-01

    Full Text Available Interest in artificial recharge of groundwater using pretreated wastewater continues to increase, especially in semi-arid countries. After the artificial recharge and natural treatment, the water could be extracted through boreholes pumping for direct irrigation. The selection of suitable locations for artificial recharge should be based on hydrogeological conditions, economic evaluation and environmental considerations. Clogging of boreholes that are used for artificial recharge is a serious problem and requires proper planning to reduce it. This paper deals with the investigation of the possibilities and prospects of aquifer recharge via boreholes using treated wastewater. Firstly, the aquifer recharge techniques, the proposed criteria of waste and the clogging effect are presented. Secondly, the possibility of application of artificial recharge in the South-Eastern Mesaoria aquifer of Cyprus is examined. Based on hydrogeological results, artificial recharge using tertiary treated wastewater via boreholes is one of the options available for increasing the groundwater reserves of this aquifer. The recycled water will infiltrate through gravel pack, providing favorable conditions for ventilation and laminar flow due to small water flow velocity. The treatment works include the removal of the fat, oil and grease (FOG and cyanides (CN− content in order to meet the upper acceptable limits.

  16. Snow impact on groundwater recharge in Table Mountain Group ...

    African Journals Online (AJOL)

    Snowmelt in the mountainous areas of the Table Mountain Group (TMG) in South Africa is believed to be one of sources of groundwater recharge in some winter seasons. This paper provides a scientific assessment of snow impact on groundwater recharge in Table Mountain Group Aquifer Systems for the first time.

  17. Monitoring and modeling infiltration–recharge dynamics of managed aquifer recharge with desalinated seawater

    Directory of Open Access Journals (Sweden)

    Y. Ganot

    2017-09-01

    Full Text Available 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.

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

    Science.gov (United States)

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

    2006-01-01

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

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

    Science.gov (United States)

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

    2006-10-01

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

  20. Emulation of recharge and evapotranspiration processes in shallow groundwater systems

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Ayvaz, M Tamer; Elçi, Alper

    2014-01-01

    The quantification of groundwater recharge is an important but challenging task in groundwater flow modeling because recharge varies spatially and temporally. The goal of this study is to present an innovative methodology to estimate groundwater recharge rates and zone structures for regional groundwater flow models. Here, the unknown recharge field is partitioned into a number of zones using Voronoi Tessellation (VT). The identified zone structure with the recharge rates is associated through a simulation-optimization model that couples MODFLOW-2000 and the hybrid PSOLVER optimization algorithm. Applicability of this procedure is tested on a previously developed groundwater flow model of the Tahtalı Watershed. Successive zone structure solutions are obtained in an additive manner and penalty functions are used in the procedure to obtain realistic and plausible solutions. One of these functions constrains the optimization by forcing the sum of recharge rates for the grid cells that coincide with the Tahtalı Watershed area to be equal to the areal recharge rate determined in the previous modeling by a separate precipitation-runoff model. As a result, a six-zone structure is selected as the best zone structure that represents the areal recharge distribution. Comparison to results of a previous model for the same study area reveals that the proposed procedure significantly improves model performance with respect to calibration statistics. The proposed identification procedure can be thought of as an effective way to determine the recharge zone structure for groundwater flow models, in particular for situations where tangible information about groundwater recharge distribution does not exist. © 2013, National Ground Water Association.

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

    Science.gov (United States)

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

    2016-03-01

    Groundwater recharge estimation is a critical quantity for sustainable groundwater management. The feasibility and robustness of recharge estimation was evaluated using physical-based modeling procedures, and data from a low-cost weather station with remote sensor techniques in Southern Abbotsford, British Columbia, Canada. Recharge was determined using the Richards-based vadose zone hydrological model, HYDRUS-1D. The required meteorological data were recorded with a HOBO(TM) weather station for a short observation period (about 1 year) and an existing weather station (Abbotsford A) for long-term study purpose (27 years). Undisturbed soil cores were taken at two locations in the vicinity of the HOBO(TM) weather station. The derived soil hydraulic parameters were used to characterize the soil in the numerical model. Model performance was evaluated using observed soil moisture and soil temperature data obtained from subsurface remote sensors. A rigorous sensitivity analysis was used to test the robustness of the model. Recharge during the short observation period was estimated at 863 and 816 mm. The mean annual recharge was estimated at 848 and 859 mm/year based on a time series of 27 years. The relative ratio of annual recharge-precipitation varied from 43% to 69%. From a monthly recharge perspective, the majority (80%) of recharge due to precipitation occurred during the hydrologic winter period. The comparison of the recharge estimates with other studies indicates a good agreement. Furthermore, this method is able to predict transient recharge estimates, and can provide a reasonable tool for estimates on nutrient leaching that is often controlled by strong precipitation events and rapid infiltration of water and nitrate into the soil. © 2015, National Ground Water Association.

  3. Solid-state rechargeable magnesium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Chusid, O.; Gofer, Y.; Gizbar, H.; Vestfrid, Y.; Levi, E.; Aurbach, D. [Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900 (Israel); Riech, I. [Ortal Magnesium Diecasting Ltd, Kibbutz Neve Ur 10875 (Israel)

    2003-04-17

    The development of all solid-state rechargeable magnesium battery systems is reported, with components that are environmentally friendly and relatively simple in their structure and preparation. As anodes, magnesium alloys containing Zn and Al are used, and the cathode is the chevrel phase, Mo{sub 6}S{sub 8}, which can insert two magnesium atoms per unit (Mg{sub 2}Mo{sub 6}S{sub 8}, 122 mA h g{sup -1}). The solid electrolyte is a gel comprising polyvinylidene difluoride, Mg(AlCl{sub 2}EtBt){sub 2} complex salt, and tetraglyme as a plasticizer. These batteries are found to function well in a temperature range of 0-80 C with a voltage range of 1.3-0.8V. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  4. High specific power lithium polymer rechargeable battery

    Energy Technology Data Exchange (ETDEWEB)

    Chu, M.Y.; De Jonghe, L.; Visco, S. [PolyPlus Battery Co., Berkeley, CA (United States)

    1996-11-01

    PolyPlus Battery Company (PPBC) is developing an advanced lithium polymer rechargeable battery based on its proprietary positive electrode. This battery offers high steady-state (> 250 W/kg) and peak power densities (3,000 W/kg), in a low cost and environmentally benign format. This PolyPlus lithium polymer battery also delivers high specific energy. The first generation battery has an energy density of 100 Wh/kg (120 Wh/l) and subsequent generations increases the performance in excess of 500 Wh/kg (600 Wh/l). The high power and energy densities, along with the low toxicity and low cost of materials used in the PolyPlus solid-state cell makes this battery exceptionally attractive for both hybrid and electric vehicle applications.

  5. Echo Meadows Project Winter Artificial Recharge.

    Energy Technology Data Exchange (ETDEWEB)

    Ziari, Fred

    2002-12-19

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

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

    Science.gov (United States)

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

    2013-05-01

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

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

    Science.gov (United States)

    Williams, Alan E.

    1997-12-01

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

  8. Quantifying potential recharge in mantled sinkholes using ERT.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2010-01-01

    A Monte Carlo-based approach to assess uncertainty in recharge areas shows that incorporation of atmospheric tracer observations (in this case, tritium concentration) and prior information on model parameters leads to more precise predictions of recharge areas. Variance-covariance matrices, from model calibration and calculation of sensitivities, were used to generate parameter sets that account for parameter correlation and uncertainty. Constraining parameter sets to those that met acceptance criteria, which included a standard error criterion, did not appear to bias model results. Although the addition of atmospheric tracer observations and prior information produced similar changes in the extent of predicted recharge areas, prior information had the effect of increasing probabilities within the recharge area to a greater extent than atmospheric tracer observations. Uncertainty in the recharge area propagates into predictions that directly affect water quality, such as land cover in the recharge area associated with a well and the residence time associated with the well. Assessments of well vulnerability that depend on these factors should include an assessment of model parameter uncertainty. A formal simulation of parameter uncertainty can be used to delineate probabilistic recharge areas, and the results can be expressed in ways that can be useful to water-resource managers. Although no one model is the correct model, the results of multiple models can be evaluated in terms of the decision being made and the probability of a given outcome from each model. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

  10. Groundwater recharge: The intersection between humanity and hydrogeology

    Science.gov (United States)

    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).

  11. Distribution of Groundwater Recharge in Fractured/Karst Aquifers

    Science.gov (United States)

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

    2015-12-01

    Accurate estimation of groundwater recharge is important to evaluate aquifer's water balance. Spatial and temporal distribution of the recharge depends on variability of hydraulic properties of rock. This variability is larger for sedimentary fractured environments where fast and slow flow paths exist. Therefore, quantifying groundwater fluxes through various rock sections within the vadose zone and into the aquifer is of critical importance for determining aquifers storage deviation. The research objective was to investigate how the lithology changes influence flow in the unsaturated zone and the spatial and temporal variation of groundwater recharge. To assess these variations for the Western Mountain Aquifer (Yarkon-Taninim) of Israel, we considered a range of parameters values for both fractures/karst and porous media, namely; permeability, block size, spacing between fractures, karst volumetric volume, etc. A conceptual model was built for nine monitoring wells sites in the study area. A one-dimensional, dual permeability mathematical model of water flow in a variably saturated, fractured/karst-porous media was applied to simulate water flow in each location. Model parameters were determined by solving the inverse problem using data of groundwater level observations. The results of simulation show that the highest groundwater replenishment occurs in locations where fast flow paths conditions are expected, while the lowest recharges took place in locations containing low permeability layers. The spatial differences in recharge are larger during years with high precipitation which can reach a few hundred percent. Additionally, fast and slow flow paths conditions also influence annual cumulative groundwater recharge dynamic. In areas where fast flow paths exist, most of the groundwater recharge occurs during the rainy season (60-80% of the total recharge for the tested years), while in locations with slow flow path conditions the recharge rate stays relatively

  12. Joint Estimation of Spatial Variable Transmissivities and Recharge

    Science.gov (United States)

    Hendricks Franssen, H. J. W. M.; Stauffer, F.; Kinzelbach, W.

    Uncertainty in the input parameters of groundwater flow and mass transport models is an important cause of model prediction uncertainty. On one side, it is important to characterise this uncertainty in a stochastic approach. On the other side, it is fundamental to reduce the uncertainty by efficient use of available measurement data. The sequential self-calibrated approach, a Monte-Carlo type inverse modelling approach, is able to generate a large number of multiple equally likely solutions to a groundwater flow and mass transport problem that are conditioned to conductivity, storativity, head and concentration data, among others. Frequently the calibration is limited to the spatially variable transmissivities. In other cases it may be necessary to estimate also spatially variable storativities, recharge rates, boundary conditions or porosities. In practical problems such as the determination of a, possibly time-dependent, drinking water well capture zone usually recharge and transmissivities have to be estimated jointly. A synthetic study that mimics such a practical problem illustrates the joint estimation of spatially variable transmissivities and recharge. It is found that in most practical situations it is not necessary to estimate the detailed spatial pattern of recharge. However, it is important to consider the uncertainty in the mean recharge. With respect to transmissivities on the other hand, the mean is of little relevance for the estimation of capture zones, while the spatial variability is important. In the example, transmissivities and recharge could successfully be estimated jointly, improving both the characterisation of the spatially variable transmissivities and the spatially variable recharge. Conditioning to hydraulic head data, correlated with both the recharges and the transmissivities through the groundwater flow equation, allows to improve the estimation of transmissivities and recharge.

  13. Can we calibrate simultaneously groundwater recharge and aquifer hydrodynamic parameters ?

    Science.gov (United States)

    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

  14. A VISUAL BASIC PPREADSHEET MACRO FOR ESTIMATING GROUNDWATER RECHARGE

    Directory of Open Access Journals (Sweden)

    Kristijan Posavec

    2009-12-01

    Full Text Available A Visual Basic spreadsheet macro was written to automate the estimation of groundwater recharge from stream or spring hydrographs using the adapted Meyboom’s method. The program fits exponential regression model available in widely accessible platform (i.e. MS Excel to baseflow recessions that precede and follow groundwater recharge, and uses regression equations to calculate recharge volume that occur between these recessions. An example of field data from Croatia (Bulaž spring is given to illustrate its application.

  15. Recharge contribution to the Guarani Aquifer System estimated from the water balance method in a representative watershed.

    Science.gov (United States)

    Wendland, Edson; Gomes, Luis H; Troeger, Uwe

    2015-01-01

    The contribution of recharge to regional groundwater flow systems is essential information required to establish sustainable water resources management. The objective of this work was to determine the groundwater outflow in the Ribeirão da Onça Basin using a water balance model of the saturated soil zone. The basin is located in the outcrop region of the Guarani Aquifer System (GAS). The water balance method involved the determination of direct recharge values, groundwater storage variation and base flow. The direct recharge was determined by the water table fluctuation method (WTF). The base flow was calculated by the hydrograph separation method, which was generated by a rain-flow model supported by biweekly streamflow measurements in the control section. Undisturbed soil samples were collected at depths corresponding to the variation zone of the groundwater level to determine the specific yield of the soil (drainable porosity). Water balances were performed in the saturated zone for the hydrological years from February 2004 to January 2007. The direct recharge ranged from 14.0% to 38.0%, and groundwater outflow from 0.4% to 2.4% of the respective rainfall during the same period.

  16. Pioneering Ekofisk system to inject gas at 9200 psi

    Energy Technology Data Exchange (ETDEWEB)

    1974-02-01

    A schematic shows various steps to Ekofisk gas injection. Phillips Petroleum Co. will have in operation late this year or early in 1975 a pioneering type high pressure gas injection system at its North Sea Ekofisk field complex designed to inject up to 500 MMcfd at 9,200 psi. The system will enable Phillips to conserve gas and maintain reservoir pressure in production of Ekofisk crude. Constructed by the packaged compressor division of Dresser Industries, the complete high pressure system, including compressor trains, heat exchangers, injection manifold and headers, and control equipment was built on barges at Dresser's Houston, Texas, facility. The complete system has been installed at 4 Ekofisk platforms, FTP and C after it was towed from Texas to the North Sea. Physical layout of the high pressure system is in 3 sections: a center section contains heat exchangers and control apparatus, and on either side identical compressor trains. All compression equipment, 6 units totalling 110,000 hp, are driven by gas turbines. Discharge pressure of the 2 reinjection compressors, 9,200 psig, represents a record high for centrifugal compressors.

  17. In Situ Electrochemistry of Rechargeable Battery Materials: Status Report and Perspectives.

    Science.gov (United States)

    Yang, Yijun; Liu, Xizheng; Dai, Zhonghua; Yuan, Fangli; Bando, Yoshio; Golberg, Dmitri; Wang, Xi

    2017-08-01

    The development of rechargeable batteries with high performance is considered to be a feasible way to satisfy the increasing needs of electric vehicles and portable devices. It is of vital importance to design electrodes with high electrochemical performance and to understand the nature of the electrode/electrolyte interfaces during battery operation, which allows a direct observation of the complicated chemical and physical processes within the electrodes and electrolyte, and thus provides real-time information for further design and optimization of the battery performance. Here, the recent progress in in situ techniques employed for the investigations of material structural evolutions is described, including characterization using neutrons, X-ray diffraction, and nuclear magnetic resonance. In situ techniques utilized for in-depth uncovering the electrode/electrolyte phase/interface change mechanisms are then highlighted, including transmission electron microscopy, atomic force microscopy, X-ray spectroscopy, and Raman spectroscopy. The real-time monitoring of lithium dendrite growth and in situ detection of gas evolution during charge/discharge processes are also discussed. Finally, the major challenges and opportunities of in situ characterization techniques are outlined toward new developments of rechargeable batteries, including innovation in the design of compatible in situ cells, applications of dynamic analysis, and in situ electrochemistry under multi-stimuli. A clear and in-depth understanding of in situ technique applications and the mechanisms of structural evolutions, surface/interface changes, and gas generations within rechargeable batteries is given here. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Glacierized headwater streams as aquifer recharge corridors, subarctic Alaska

    Science.gov (United States)

    Liljedahl, A. K.; Gädeke, A.; O'Neel, S.; Gatesman, T. A.; Douglas, T. A.

    2017-07-01

    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.

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

    Science.gov (United States)

    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.

  20. Glacierized headwater streams as aquifer recharge corridors, subarctic Alaska

    Science.gov (United States)

    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.

  1. Evaluating drywells for stormwater management and enhanced aquifer recharge

    Science.gov (United States)

    Drywells are increasingly used for stormwater management and enhanced aquifer recharge, but only limited research has quantitatively determined drywell performance. Numerical and field experiments were therefore conducted to improve our understanding and ability to characterize drywell behavior. I...

  2. Groundwater Modelling For Recharge Estimation Using Satellite Based Evapotranspiration

    Science.gov (United States)

    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

  3. Wearable textile battery rechargeable by solar energy.

    Science.gov (United States)

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

    2013-01-01

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

  4. Thin-film Rechargeable Lithium Batteries

    Science.gov (United States)

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

    1993-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-10-27

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

  6. Predicting groundwater recharge for varying landcover and climate conditions: – a global meta-study

    OpenAIRE

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

    2017-01-01

    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. The aims of this study were to identify the most influential factors on groundwater recharge, and to develop an empirical model to estimate diffuse rainfall recharge at a glo...

  7. Recharge signal identification based on groundwater level observations.

    Science.gov (United States)

    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.

  8. Current Status of the Nitrogen Oxygen Recharge System

    Science.gov (United States)

    Dick, Brandon

    2011-01-01

    This paper presents an overview of the Nitrogen Oxygen Recharge System (NORS) to date and the current development status of the system. NORS is an element of the International Space Station (ISS) Environmental Control and Life Support Systems (ECLSS) used to resupply the ISS with Nitrogen and Oxygen following the impending retirement of the Space Shuttle. The paper will discuss why NASA is developing NORS, including a summary of other concepts considered, and other related concepts currently being developed by NASA. The current system architecture will be described, along with a summary of the current design of the NORS. The overall programmatic schedule of the NORS in the context of the upcoming shuttle retirement and future launch vehicle development will also be presented. Finally, the paper will examine the significant technical challenges encountered during the requirements and preliminary design phase of NORS development. A key challenge to the development of NORS is the international shipment - and associated regulations - of pressurized Oxygen, which is necessary due to the use of launch vehicles based in Japan and French Guiana to send NORS gasses to the ISS. The storage and use of relatively large quantities of high pressure (41,000 kPa) Oxygen and Nitrogen within the ISS, which is unprecedented both on the ISS and other space vehicles, has had a significant impact on the design and architecture of the system. The high pressure of the system also poses unique thermal considerations, which has led to the development of a heater system for thermal conditioning of high pressure gas to avoid thermal impacts on downstream hardware. The on-orbit envelope allocated to the NORS has changed (gotten smaller) and has impacted both the design and architecture of the system. Finally, the balance of safety considerations associated with these high pressure gasses, particularly high pressure Oxygen, with the functionality of the system has profoundly impacted the form

  9. Design and simulation of lithium rechargeable batteries

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, C.M.

    1995-08-01

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

  10. Arsenic release during managed aquifer recharge (MAR)

    Science.gov (United States)

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

    2013-12-01

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

  11. High Recharge Areas in the Choushui River Alluvial Fan (Taiwan Assessed from Recharge Potential Analysis and Average Storage Variation Indexes

    Directory of Open Access Journals (Sweden)

    Jui-Pin Tsai

    2015-03-01

    Full Text Available High recharge areas significantly influence the groundwater quality and quantity in regional groundwater systems. Many studies have applied recharge potential analysis (RPA to estimate groundwater recharge potential (GRP and have delineated high recharge areas based on the estimated GRP. However, most of these studies define the RPA parameters with supposition, and this represents a major source of uncertainty for applying RPA. To objectively define the RPA parameter values without supposition, this study proposes a systematic method based on the theory of parameter identification. A surrogate variable, namely the average storage variation (ASV index, is developed to calibrate the RPA parameters, because of the lack of direct GRP observations. The study results show that the correlations between the ASV indexes and computed GRP values improved from 0.67 before calibration to 0.85 after calibration, thus indicating that the calibrated RPA parameters represent the recharge characteristics of the study area well; these data also highlight how defining the RPA parameters with ASV indexes can help to improve the accuracy. The calibrated RPA parameters were used to estimate the GRP distribution of the study area, and the GRP values were graded into five levels. High and excellent level areas are defined as high recharge areas, which composed 7.92% of the study area. Overall, this study demonstrates that the developed approach can objectively define the RPA parameters and high recharge areas of the Choushui River alluvial fan, and the results should serve as valuable references for the Taiwanese government in their efforts to conserve the groundwater quality and quantity of the study area.

  12. Fate of human viruses in groundwater recharge systems

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-03-01

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

  13. Geochemical Triggers of Arsenic Mobilization during Managed Aquifer Recharge.

    Science.gov (United States)

    Fakhreddine, Sarah; Dittmar, Jessica; Phipps, Don; Dadakis, Jason; Fendorf, Scott

    2015-07-07

    Mobilization of arsenic and other trace metal contaminants during managed aquifer recharge (MAR) poses a challenge to maintaining local groundwater quality and to ensuring the viability of aquifer storage and recovery techniques. Arsenic release from sediments into solution has occurred during purified recycled water recharge of shallow aquifers within Orange County, CA. Accordingly, we examine the geochemical processes controlling As desorption and mobilization from shallow, aerated sediments underlying MAR infiltration basins. Further, we conducted a series of batch and column experiments to evaluate recharge water chemistries that minimize the propensity of As desorption from the aquifer sediments. Within the shallow Orange County Groundwater Basin sediments, the divalent cations Ca(2+) and Mg(2+) are critical for limiting arsenic desorption; they promote As (as arsenate) adsorption to the phyllosilicate clay minerals of the aquifer. While native groundwater contains adequate concentrations of dissolved Ca(2+) and Mg(2+), these cations are not present at sufficient concentrations during recharge of highly purified recycled water. Subsequently, the absence of dissolved Ca(2+) and Mg(2+) displaces As from the sediments into solution. Increasing the dosages of common water treatment amendments including quicklime (Ca(OH)2) and dolomitic lime (CaO·MgO) provides recharge water with higher concentrations of Ca(2+) and Mg(2+) ions and subsequently decreases the release of As during infiltration.

  14. Karst Aquifer Recharge: Comments on Somaratne, N. Characteristics of Point Recharge in Karst Aquifers. Water 2014, 6, 2782–2807

    Directory of Open Access Journals (Sweden)

    Adrian D. Werner

    2014-11-01

    Full Text Available The article “Characteristics of Point Recharge in Karst Aquifers, Water 6: 2782–2807” by N. Somaratne evaluates various recharge estimation techniques applied to four limestone aquifers in South Australia. Somaratne [1] concludes that methods based on watertable fluctuations, groundwater modelling and water budgets are independent of recharge processes, and are therefore superior to the chloride mass balance (CMB approach for karst aquifers. The current comment offers alternative interpretations from existing field measurements and previous literature, in particular for the Uley South aquifer, which is the focus of much of the article by Somaratne [1]. Conclusions regarding this system are revised, partly to account for the misrepresentation of previous studies. The aeolianite sediments of Uley South are mostly unconsolidated or poorly consolidated, and dissolution features in the calcrete capping provide point infiltration into a predominantly unconsolidated vadose zone, whereas Somaratne’s [1] findings require that the system comprises well-developed conduits in otherwise low-conductivity limestone. Somaratne’s [1] assertion that the basic premise of CMB is violated in Uley South is disputable, given strong evidence of relatively well-mixed groundwater arising from mostly diffuse recharge. The characterization of karst aquifer recharge should continue to rely on multiple techniques, including environmental tracers such as chloride.

  15. A rechargeable Li-CO{sub 2} battery with a gel polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chao; Guo, Ziyang; Yang, Bingchang; Liu, Yao; Wang, Yonggang; Xia, Yongyao [Dept. of Chemistry and Shanghai Key Lab. of Molecular Catalysis and Innovative Materials, Inst. of New Energy, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Fudan Univ. (China)

    2017-07-24

    The utilization of CO{sub 2} in Li-CO{sub 2} batteries is attracting extensive attention. However, the poor rechargeability and low applied current density have remained the Achilles' heel of this energy device. The gel polymer electrolyte (GPE), which is composed of a polymer matrix filled with tetraglyme-based liquid electrolyte, was used to fabricate a rechargeable Li-CO{sub 2} battery with a carbon nanotube-based gas electrode. The discharge product of Li{sub 2}CO{sub 3} formed in the GPE-based Li-CO{sub 2} battery exhibits a particle-shaped morphology with poor crystallinity, which is different from the contiguous polymer-like and crystalline discharge product in conventional Li-CO{sub 2} battery using a liquid electrolyte. Accordingly, the GPE-based battery shows much improved electrochemical performance. The achieved cycle life (60 cycles) and rate capability (maximum applied current density of 500 mA g{sup -1}) are much higher than most of previous reports, which points a new way to develop high-performance Li-CO{sub 2} batteries. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Identifying Seasonal Groundwater Recharge Using Environmental Stable Isotopes

    Directory of Open Access Journals (Sweden)

    Hsin-Fu Yeh

    2014-09-01

    Full Text Available In this study, the stable isotope values of oxygen and hydrogen were used to identify the seasonal contribution ratios of precipitation to groundwater recharge in the Hualien River basin of eastern Taiwan. The differences and correlations of isotopes in various water bodies were examined to evaluate the groundwater recharge sources for the Hualian River basin and the interrelations between groundwater and surface water. Proportions of recharge sources were calculated based on the results of the mass balance analysis of the isotope composition of hydrogen and oxygen in the basin. Mountain river water accounted for 83% and plain rainfall accounted for 17% of the groundwater recharge in the Huanlian River basin. Using the mean d-values, a comparison of d-values of precipitation and groundwater indicates the groundwater consists of 75.5% wet seasonal sources and 24.5% dry seasonal sources, representing a distinct seasonal variation of groundwater recharge in the study area. Comparisons between hydrogen and oxygen isotopes in rainwater showed that differences in the amount of rainfall resulted in depleted oxygen and hydrogen isotopes for precipitation in wet seasons as compared to dry seasons. The river water contained more depleted hydrogen and oxygen isotopes than was the case for precipitation, implying that the river water mainly came from the upstream catchment. In addition, the hydrogen and oxygen isotopes in the groundwater slightly deviated from the hydrogen and oxygen isotopic meteoric water line in Huanlian. Therefore, the groundwater in this basin might be a mixture of river water and precipitation, resulting in the effect of the river water recharge being greater than that of rainfall infiltration.

  17. Estimating aquifer channel recharge using optical data interpretation.

    Science.gov (United States)

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

    2012-01-01

    Recharge through intermittent and ephemeral stream channels is believed to be a primary aquifer recharge process in arid and semiarid environments. The intermittent nature of precipitation and flow events in these channels, and their often remote locations, makes direct flow and loss measurements difficult and expensive. Airborne and satellite optical images were interpreted to evaluate aquifer recharge due to stream losses on the Frio River in south-central Texas. Losses in the Frio River are believed to be a major contributor of recharge to the Edwards Aquifer. The results of this work indicate that interpretation of readily available remote sensing optical images can offer important insights into the spatial distribution of aquifer recharge from losing streams. In cases where upstream gauging data are available, simple visual analysis of the length of the flowing reach downstream from the gauging station can be used to estimate channel losses. In the case of the Frio River, the rate of channel loss estimated from the length of the flowing reach at low flows was about half of the loss rate calculated from in-stream gain-loss measurements. Analysis based on water-surface width and channel slope indicated that losses were mainly in a reach downstream of the mapped recharge zone. The analysis based on water-surface width, however, did not indicate that this method could yield accurate estimates of actual flow in pool and riffle streams, such as the Frio River and similar rivers draining the Edwards Plateau. © 2011, Southwest Research Institute. Ground Water © 2011, National Ground Water Association.

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

    Science.gov (United States)

    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.

    2007-01-01

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

  19. Modelling of recharge and pollutant fluxes to urban groundwaters.

    Science.gov (United States)

    Thomas, Abraham; Tellam, John

    2006-05-01

    Urban groundwater resources are of considerable importance to the long-term viability of many cities world-wide, yet prediction of the quantity and quality of recharge is only rarely attempted at anything other than a very basic level. This paper describes the development of UGIf, a simple model written within a GIS, designed to provide estimates of spatially distributed recharge and recharge water quality in unconfined but covered aquifers. The following processes (with their calculation method indicated) are included: runoff and interception (curve number method); evapotranspiration (Penman-Grindley); interflow (empirical index approach); volatilization (Henry's law); sorption (distribution coefficient); and degradation (first order decay). The input data required are: meteorological data, landuse/cover map with event mean concentration attributes, geological maps with hydraulic and geochemical attributes, and topographic and water table elevation data in grid form. Standard outputs include distributions of: surface runoff, infiltration, potential recharge, ground level slope, interflow, actual recharge, pollutant fluxes in surface runoff, travel times of each pollutant through the unsaturated zone, and the pollutant fluxes and concentrations at the water table. The process of validation has commenced with a study of the Triassic Sandstone aquifer underlying Birmingham, UK. UGIf predicts a similar average recharge rate for the aquifer as previous groundwater flow modelling studies, but with significantly more spatial detail: in particular the results indicate that recharge through paved areas may be more important than previously thought. The results also highlight the need for more knowledge/data on the following: runoff estimation; interflow (including the effects of lateral flow and channelling on flow times and therefore chemistry); evapotranspiration in paved areas; the nature of unsaturated zone flow below paved areas; and the role of the pipe network

  20. Sensitivity of groundwater recharge using climatic analogues and HYDRUS-1D

    National Research Council Canada - National Science Library

    Leterme, B; Mallants, D; Jacques, D

    2012-01-01

    ...; this includes estimation of groundwater recharge for the next millennia. Groundwater recharge was simulated using the Richards based soil water balance model HYDRUS-1D and meteorological time series from analogue stations...

  1. High-efficiency and high-power rechargeable lithium-sulfur dioxide batteries exploiting conventional carbonate-based electrolytes

    Science.gov (United States)

    Park, Hyeokjun; Lim, Hee-Dae; Lim, Hyung-Kyu; Seong, Won Mo; Moon, Sehwan; Ko, Youngmin; Lee, Byungju; Bae, Youngjoon; Kim, Hyungjun; Kang, Kisuk

    2017-05-01

    Shedding new light on conventional batteries sometimes inspires a chemistry adoptable for rechargeable batteries. Recently, the primary lithium-sulfur dioxide battery, which offers a high energy density and long shelf-life, is successfully renewed as a promising rechargeable system exhibiting small polarization and good reversibility. Here, we demonstrate for the first time that reversible operation of the lithium-sulfur dioxide battery is also possible by exploiting conventional carbonate-based electrolytes. Theoretical and experimental studies reveal that the sulfur dioxide electrochemistry is highly stable in carbonate-based electrolytes, enabling the reversible formation of lithium dithionite. The use of the carbonate-based electrolyte leads to a remarkable enhancement of power and reversibility; furthermore, the optimized lithium-sulfur dioxide battery with catalysts achieves outstanding cycle stability for over 450 cycles with 0.2 V polarization. This study highlights the potential promise of lithium-sulfur dioxide chemistry along with the viability of conventional carbonate-based electrolytes in metal-gas rechargeable systems.

  2. High-efficiency and high-power rechargeable lithium-sulfur dioxide batteries exploiting conventional carbonate-based electrolytes.

    Science.gov (United States)

    Park, Hyeokjun; Lim, Hee-Dae; Lim, Hyung-Kyu; Seong, Won Mo; Moon, Sehwan; Ko, Youngmin; Lee, Byungju; Bae, Youngjoon; Kim, Hyungjun; Kang, Kisuk

    2017-05-11

    Shedding new light on conventional batteries sometimes inspires a chemistry adoptable for rechargeable batteries. Recently, the primary lithium-sulfur dioxide battery, which offers a high energy density and long shelf-life, is successfully renewed as a promising rechargeable system exhibiting small polarization and good reversibility. Here, we demonstrate for the first time that reversible operation of the lithium-sulfur dioxide battery is also possible by exploiting conventional carbonate-based electrolytes. Theoretical and experimental studies reveal that the sulfur dioxide electrochemistry is highly stable in carbonate-based electrolytes, enabling the reversible formation of lithium dithionite. The use of the carbonate-based electrolyte leads to a remarkable enhancement of power and reversibility; furthermore, the optimized lithium-sulfur dioxide battery with catalysts achieves outstanding cycle stability for over 450 cycles with 0.2 V polarization. This study highlights the potential promise of lithium-sulfur dioxide chemistry along with the viability of conventional carbonate-based electrolytes in metal-gas rechargeable systems.

  3. Alkaline solid polymer electrolytes and their application to rechargeable batteries; Electrolytes solides polymeres alcalins application aux generateurs electrochimiques rechargeables

    Energy Technology Data Exchange (ETDEWEB)

    Guinot, S.

    1996-03-15

    A new family of solid polymer electrolytes (SPE) based on polyoxyethylene (POE), KOH and water is investigated in view of its use in rechargeable batteries. After a short review on rechargeable batteries, the preparation of various electrolyte compositions is described. Their characterization by differential scanning calorimetry (DSC), thermogravimetric analysis, X-ray diffraction and microscopy confirm a multi-phasic structure. Conductivity measurements give values up to 10 sup -3 S cm sup -1 at room temperature. Their use in cells with nickel as negative electrode and cadmium or zinc as positive electrode has been tested; cycling possibility has been shown to be satisfactory. (C.B.) 113 refs.

  4. Groundwater recharge estimation and water resources assessment in a tropical crystalline basement aquifer

    OpenAIRE

    Nyagwambo, N.L.

    2006-01-01

    While most groundwater recharge estimation methods give reasonable long-term annual average estimates very few if any methods offer guidance on monthly recharge. In crystalline basement aquifers (CBAs) the problem is compounded by the high seasonal, intra-annual and inter-annual variability. The chloride mass balance (CMB), the daily catchment water balance (WB) and the water table fluctuation (WTF) groundwater recharge estimation methods have been used to estimate groundwater recharge in a s...

  5. Estimating groundwater recharge using land use and soil data: A case study in South India

    NARCIS (Netherlands)

    Anuraga, T.S.K.; Ruiz, L.; Mohan Kumar, M.S.; Sekhar, M.; Leijnse, A.

    2006-01-01

    Groundwater recharge is a key factor in water balance studies, especially in semi-arid areas. In India, the Groundwater Evaluation Committee recommends the use of the ¿water table rise method¿ to evaluate recharge. However, this method does not account for spatial variation of recharge, which can be

  6. 78 FR 38093 - Thirteenth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

    Science.gov (United States)

    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...

  7. Groundwater recharge estimation and water resources assessment in a tropical crystalline basement aquifer

    NARCIS (Netherlands)

    Nyagwambo, N.L.

    2006-01-01

    Groundwater recharge estimation in crystalline basement aquifers in semi-arid tropical areas is best estimated at monthly time scales as this best captures the dynamics of recharge processes in these areas. Whilst it is standard practice to use at least two methods to estimate the recharge it may be

  8. GIS and SBF for estimating groundwater recharge of a mountainous ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 123; Issue 3. GIS and SBF for estimating groundwater recharge of a ... The temporal and spatial distributions of precipitation are extremely uneven; so, careful management of water resources in Taiwan is crucial. The long-term overexploitation of groundwater ...

  9. Delineation of the recharge areas and distinguishing the sources of ...

    Indian Academy of Sciences (India)

    8

    sinkholes also support the Bringi stream as an ideal source of recharge. Based on the .... hazards in karst. Environmental Geology 58:235-237. Payne BR., Yurtsever Y. 1974. Environmental isotopes as hydrogeological tool in Nicaragua, In. Proceedings of a ... Aquifer System, Everglades National Park, Florida, USA.

  10. Groundwater recharge: an overview of processes and challenges

    NARCIS (Netherlands)

    de Vries, J.J.; Simmers, I.

    2002-01-01

    Since the mid-1980s, a relative explosion of groundwater-recharge studies has been reported in the literature. It is therefore relevant to assess what is now known and to offer further guidance to practitioners involved in water-resource development. The paper summarizes current understanding of

  11. Estimating Groundwater Mounding in Sloping Aquifers for Managed Aquifer Recharge.

    Science.gov (United States)

    Zlotnik, Vitaly A; Kacimov, Anvar; Al-Maktoumi, Ali

    2017-11-01

    Design of managed aquifer recharge (MAR) for augmentation of groundwater resources often lacks detailed data, and simple diagnostic tools for evaluation of the water table in a broad range of parameters are needed. In many large-scale MAR projects, the effect of a regional aquifer base dip cannot be ignored due to the scale of recharge sources (e.g., wadis, streams, reservoirs). However, Hantush's (1967) solution for a horizontal aquifer base is commonly used. To address sloping aquifers, a new closed-form analytical solution for water table mound accounts for the geometry and orientation of recharge sources at the land surface with respect to the aquifer base dip. The solution, based on the Dupiuit-Forchheimer approximation, Green's function method, and coordinate transformations is convenient for computing. This solution reveals important MAR traits in variance with Hantush's solution: mounding is limited in time and space; elevation of the mound is strongly affected by the dip angle; and the peak of the mound moves over time. These findings have important practical implications for assessment of various MAR scenarios, including waterlogging potential and determining proper rates of recharge. Computations are illustrated for several characteristic MAR settings. © 2017, National Ground Water Association.

  12. Page 1 Storage of surface flows through groundwater recharge 175 ...

    Indian Academy of Sciences (India)

    Saul'yev V K 1964 Integration of the equation of the parabolic type by the method of nets (Oxford; Pergamon. Press). Srivastava V K 1976 Study of induced groundwater recharge, Ph.D. Thesis, Indian Institute of Technology,. New Delhi. Thomas Jr H A, Burden R P 1965 Indus river basin studies (mimeo) Division of ...

  13. Soil moisture and groundwater recharge under a mixed conifer forest

    Science.gov (United States)

    Robert R. Ziemer

    1978-01-01

    The depletion of soil moisture within the surface 7 m by a mixed conifer forest in the Sierra Nevada was measured by the neutron method every 2 weeks during 5 consecutive summers. Soil moisture recharge was measured periodically during the intervening winters. Groundwater fluctuations within the surface 17 m were continuously recorded during the same period.

  14. Fluoride release/recharging ability and bond strength of glass ...

    African Journals Online (AJOL)

    release as well as greater fluoride recharge capacity. Key words: Bond strength, caries-affected dentin, fluoride release, glass ionomer cements. Date of Acceptance: 17-Aug-2015. Introduction. The current concept of restorative dentistry is characterized by the preservation of tooth structure during cavity preparation and less ...

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

    Science.gov (United States)

    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

  16. Delineation of the recharge areas and distinguishing the sources of ...

    Indian Academy of Sciences (India)

    Water samples were collected from precipitation, streams and karst springs of the mountainous Bringi catchment of Kashmir Himalayas for major ions, stable isotopes (δ18O and δD) and 3H analysis. The main objective is to identify the potential recharge area for karst springs. The water in the Triassic limestone aquifer of ...

  17. Predicted impacts of land use change on groundwater recharge of ...

    African Journals Online (AJOL)

    2012-04-13

    Apr 13, 2012 ... 4School of the Environment, Flinders University, GPO Box 2100, Adelaide SA 5001, Australia. ABSTRACT. Land use ... images from 1984, 1992, 2002, and 2008, and to predict the impact of these land use changes on groundwater recharge. For .... Depending on climate, vegetation is a strong determining ...

  18. Regional Assessment of Groundwater Recharge in the Lower Mekong Basin

    Directory of Open Access Journals (Sweden)

    Guillaume Lacombe

    2017-12-01

    Full Text Available Groundwater recharge remains almost totally unknown across the Mekong River Basin, hindering the evaluation of groundwater potential for irrigation. A regional regression model was developed to map groundwater recharge across the Lower Mekong Basin where agricultural water demand is increasing, especially during the dry season. The model was calibrated with baseflow computed with the local-minimum flow separation method applied to streamflow recorded in 65 unregulated sub-catchments since 1951. Our results, in agreement with previous local studies, indicate that spatial variations in groundwater recharge are predominantly controlled by the climate (rainfall and evapotranspiration while aquifer characteristics seem to play a secondary role at this regional scale. While this analysis suggests large scope for expanding agricultural groundwater use, the map derived from this study provides a simple way to assess the limits of groundwater-fed irrigation development. Further data measurements to capture local variations in hydrogeology will be required to refine the evaluation of recharge rates to support practical implementations.

  19. Delineation of the recharge areas and distinguishing the sources of ...

    Indian Academy of Sciences (India)

    The main objective is to identify the potential recharge area for karst springs. The water in the Triassic limestone aquifer of the Bringi watershed is characterized by low levels of mineralization with TDS of the spring water samples ranging between 99 and 222 mg/l except the Kongamnag spring, which contained TDS up to ...

  20. Legionella - A threat to groundwater: Pathogen transport in recharge basin.

    Science.gov (United States)

    McBurnett, Lauren R; Holt, Nathan T; Alum, Absar; Abbaszadegan, Morteza

    2018-04-15

    This study elucidates the potential risk posed by Legionella during aquifer recharge practices. Experiments were conducted using pilot-scale column simulating infiltration of bacterial surrogate and pathogen, E. coli and Legionella pneumophila, under central Arizona recharge basin conditions. A column was packed with a loamy sand media collected from a recharge basin and was fitted with six sampling ports at soil depths of 15, 30, 60, 92, 122cm and acclimated for a month with tertiary treated wastewater. Transport of Legionella appeared to be delayed compared to E. coli. The breakthrough of E. coli and Legionella at 122cm depth occurred at 3 and 24h, respectively. Slow transport of Legionella is consistent with its pleomorphic nature and variation in size and shape under low nutrient conditions. Legionella persisted for a longer time in the column, but at lower concentrations. Given the novel results of this study, the transport of Legionella into groundwater aquifers can occur through engineering recharge basin conditions creating a potential public health risk. Copyright © 2017. Published by Elsevier B.V.

  1. A synopsis of climate change effects on groundwater recharge

    Science.gov (United States)

    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.

  2. Predicted impacts of land use change on groundwater recharge of ...

    African Journals Online (AJOL)

    Land use change is a major factor influencing catchment hydrology and groundwater resources. In South ... To reduce water loss due to evapotranspiration, non-native hill slope vegetation upstream of the Berg River Dam was cut down. It was hypothesised that recharge has been increased due to this change in vegetation.

  3. Studies on groundwater recharge through surface drains | Singh ...

    African Journals Online (AJOL)

    ... for the estimation of groundwater recharge through surface drains for both free flow as well as detained flow conditions. The Dupuit-Forchheimmer equation is solved using the Crank-Nicolson central finite difference scheme, to obtain the mound height matrix. The Gaussian elimination method was used to solve the matrix ...

  4. Comparing groundwater recharge and base flow in the Bukmoongol ...

    Indian Academy of Sciences (India)

    Department of Forest Sciences, Research Institute for Agriculture & Life Sciences, College of Agriculture and. Life Sciences, Seoul National University, San 56-1, Sillim-dong, Gwanak-gu, Seoul, 151-921, Korea. ∗ e-mail: junie@snu.ac.kr. Groundwater recharge and base flow using different investigated methods are ...

  5. Ecohydrologic process modeling of mountain block groundwater recharge.

    Science.gov (United States)

    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.

  6. Groundwater suitability recharge zones modelling - A GIS application

    Science.gov (United States)

    Dabral, S.; Bhatt, B.; Joshi, J. P.; Sharma, N.

    2014-11-01

    Groundwater quality in Gujarat state is highly variable and due to multiplicity of factors viz. influenced by direct sea water encroachment, inherent sediment salinity, water logging, overexploitation leading to overall deterioration in ground water quality, coupled with domestic and industrial pollution etc. The groundwater scenario in the state is not very encouraging due to imbalance between recharge and groundwater exploitation. Further, the demand for water has increased manifold owing to agricultural, industrial and domestic requirement and this has led to water scarcity in many parts of the state, which is likely to become more severe in coming future due to both natural and manmade factors. Therefore, sustainable development of groundwater resource requires precise quantitative assessment based on reasonably valid scientific principles. Hence, delineation of groundwater potential zones (GWPZ), has acquired great significance. The present study focuses on the integrated Geospatial and Multi-Criteria Decision Making (MCDM) techniques to determine the most important contributing factors that affect the groundwater resources and also to delineate the potential zones for groundwater recharge. The multiple thematic layers of influencing parameters viz. geology, geomorphology, soil, slope, drainage density and land use, weightages were assigned to the each factor according to their relative importance as per subject experts opinion owing to the natural setup of the region. The Analytical Hierarchy Process (AHP) was applied to these factors and potential recharge zones were identified. The study area for the assessment of groundwater recharge potential zones is Mahi-Narmada inter-stream region of Gujarat state. The study shows that around 28 % region has the excellent suitability of the ground water recharge.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2010-01-01

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

  10. Spatial-temporal pattern recognition of groundwater head variations for recharge zone identification

    Science.gov (United States)

    Tsai, Jui-Pin; Chang, Liang-Cheng; Chang, Ping-Yu; Lin, Yuan-Chien; Chen, You-Cheng; Wu, Meng-Ting; Yu, Hwa-Lung

    2017-06-01

    The delineation of groundwater recharge zones is crucial for the conservation of groundwater quality and quantity. To objectively estimate groundwater recharge zones, many field surveys are required that are costly in both time and money. To facilitate the assessment of recharge zones with high efficiency and low expense, this study proposes a 'fast-filter' approach based on empirical orthogonal function analysis and applies it in a synthetic case study and to Taiwan's Yilan Plain. In the synthetic case study, we demonstrate that the proposed method can effectively identify the recharge area by considering the head variations driven by rainfall recharge. For the case of Yilan Plain application, the field investigations (i.e., collected wellbore logs and electrical resistivity tomography [ERT] surveys) and a groundwater simulation model support the recharge zones estimated by the proposed method. The study results show that within the estimated recharge zone, all of the collected wellbore logs consist of coarse grains, and thick and continuous high resistivity zones were shown in the ERT profile images. Moreover, the groundwater model indicates that the recharge within the estimated recharge zone is 57.6% of the total recharge despite that the area of the estimated zone is only 26.8% of the study area. Therefore, the proposed method is shown to delineate recharge zones at low cost.

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

    Science.gov (United States)

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

    2014-01-01

    In semiarid and arid environments, leakage from rivers is a major source of recharge to underlying unconfined aquifers. Differential river gauging is widely used to estimate the recharge. However, the methods commonly applied are limited in that the temporal resolution is event-scale or longer. In this paper, a novel method is presented for quantifying both the total recharge volume for an event, and variation in recharge rate during an event from hydrographs recorded at the upstream and downstream ends of a river reach. The proposed method is applied to river hydrographs to illustrate the method steps and investigate recharge processes occurring in a sub-catchment of the Murray Darling Basin (Australia). Interestingly, although it is the large flood events which are commonly assumed to be the main source of recharge to an aquifer, our analysis revealed that the smaller flow events were more important in providing recharge. © 2013, National Ground Water Association.

  12. Developing empirical monthly groundwater recharge equations based on modeling and remote sensing data - Modeling future groundwater recharge to predict potential climate change impacts

    Science.gov (United States)

    Gemitzi, Alexandra; Ajami, Hoori; Richnow, Hans-Hermann

    2017-03-01

    Groundwater recharge is one of main components of the water budget that is difficult to quantify due to complexity of recharge processes and limited observations. In the present work a simple regression equation for monthly groundwater recharge estimation is developed by relating simulated recharge from a calibrated Soil and Water Assessment tool (SWAT) model to effective precipitation. Monthly groundwater recharge and actual evapotranspiration (AET) were computed by applying a calibrated (SWAT) model for a ten year period (2005-2015) in Vosvozis river basin in NE Greece. SWAT actual evapotranspiration (AET) results were compared to remotely sensed AET values from the MODerate Resolution Imaging Spectroradiometer (MODIS), indicating the integrity of the modeling process. Water isotopes of 2H and 18O, originally presented herein, were used to infer recharge resources in the basin and provided additional evidence of the applicability of the developed formula. Results showed that the developed recharge estimation method can be effectively applied using MODIS evapotranspiration data, without having to adhere to numerical modeling which is many times constrained by the lack of available data especially in poorly gauged basins. Future trends of groundwater recharge up to 2100 using an ensemble of five downscaled climate change projections indicated that annual recharge will increase up to the middle of the present century and gradually decrease thereafter. However, the predicted magnitude is highly variable depending on the Global Climate Model (GCM) used. While winter recharge will likely increase in the future, summer recharge is expected to decrease as a result of temperature rise in the future.

  13. Novel Nanocomposite Materials for Advanced Li-Ion Rechargeable Batteries

    Directory of Open Access Journals (Sweden)

    Chuan Cai

    2009-09-01

    Full Text Available 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.

  14. Zinc electrode and rechargeable zinc-air battery

    Science.gov (United States)

    Ross, Jr., Philip N.

    1989-01-01

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

  15. Electrically Rechargeable Zinc-Air Batteries: Progress, Challenges, and Perspectives.

    Science.gov (United States)

    Fu, Jing; Cano, Zachary Paul; Park, Moon Gyu; Yu, Aiping; Fowler, Michael; Chen, Zhongwei

    2017-02-01

    Zinc-air batteries have attracted much attention and received revived research efforts recently due to their high energy density, which makes them a promising candidate for emerging mobile and electronic applications. Besides their high energy density, they also demonstrate other desirable characteristics, such as abundant raw materials, environmental friendliness, safety, and low cost. Here, the reaction mechanism of electrically rechargeable zinc-air batteries is discussed, different battery configurations are compared, and an in depth discussion is offered of the major issues that affect individual cellular components, along with respective strategies to alleviate these issues to enhance battery performance. Additionally, a section dedicated to battery-testing techniques and corresponding recommendations for best practices are included. Finally, a general perspective on the current limitations, recent application-targeted developments, and recommended future research directions to prolong the lifespan of electrically rechargeable zinc-air batteries is provided. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Science.gov (United States)

    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.

  17. Decentralized Multi-Charger Coordination for Wireless Rechargeable Sensor Networks

    OpenAIRE

    Mo, Lei; You, Pengcheng; Cao, Xianghui; Song, Ye-Qiong; Chen, Jiming

    2015-01-01

    International audience; Wireless charging is a promising technology for provisioning dynamic power supply in wireless rechargeable sensor networks (WRSNs). The charging equipment can be carried by some mobile nodes to enhance the charging flexibility. With such mobile chargers (MCs), the charging process should simultaneously address the MC scheduling, the moving and charging time allocation, while saving the total energy consumption of MCs. However, the efficient solutions that jointly solve...

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

    Science.gov (United States)

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

    1983-01-01

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

  19. Water Conservation and Artificial Recharge of Aquifers in India

    Energy Technology Data Exchange (ETDEWEB)

    Chandha, D. K.

    2014-10-01

    India has proud traditions and wisdom which have evolved over thousands of years for developing technologies for water conservation and groundwater recharge using surplus monsoon precipitation runoff. This is imperative as the average rainfall/precipitation period is about 27 days/year and with uneven distribution across the country. Groundwater development is now the mainstay for sustaining agricultural production and rural water supplies. As such, groundwater development is increasing at an exponential rate and the estimated draft is now 231 000 hm{sup 3} with the result that almost 15% of the groundwater development areas are showing a continuous decline of water levels. There is an anomalous situation whereby water levels are declining in 831 blocks (assessment units) out of a total of 5 723 blocks across the country, and availability of excessive 864 000 hm{sup 3} runoff in different river basins brings floods and creates water logging in some parts of the country. This non-utilizable water can be planned for creating small surface water storage and to create additional sub-surface storage through groundwater recharge. At present, total water available is estimated at 660 000 hm{sup 3} and the minimum estimated water demand will be 843 000 hm{sup 3} in 2025 and 973 000 hm{sup 3} in 2050. Therefore, if India wants sustainable food supplies and to meet domestic/industrial water requirements, there is no other option than to implement projects for water conservation/groundwater recharge. Although a number of forward looking steps have been planned by the government and other institutions, many lacunae have been observed which need to be addressed for the successful implementation of water conservation and recharge programmes. This paper discusses various practices from the pre-historic to the present day, with case studies showing technological intervention. (Author)

  20. Handling the decline of ground water using artificial recharge areas

    Science.gov (United States)

    Hidayatullah, Muhammad Shofi; Yoga, Kuncaraningrat Edi; Muslim, Dicky

    2017-11-01

    Jatinagor, a region with rapid growth cause increasing in water demand. The ground water surface in the observation area shows a decrease based on its potential. This deflation is mainly caused by the inequality between inputs and outputs of the ground water itself. The decrease of this ground water surface is also caused by the number of catchment areas that keeps decreasing. According to the data analysis of geology and hydrology, the condition of ground water in Jatinangor on 2015 had indicated a decrease compared to 2010. Nowadays, the longlivity of clean water can be ensure by the hydrogeology engineering, which is to construct an artificial recharge for ground water in use. The numerical method is aims to determine the number of ground water supply in Jatinangor. According to the research, the most suitable artificial recharge is in the form of a small dam located in the internment river. With the area of 209.000 m2, this dam will be able to contain 525 m3 runoff water with the intensity of maximum rainfall effectively 59,44 mm/hour. The increase of water volume generate by this artificial recharge, fulfilled the demand of clean water.

  1. Kamchia watershed groundwater recharge assessment by the CLM3 model

    Directory of Open Access Journals (Sweden)

    Nitcheva Olga

    2018-01-01

    Full Text Available Estimating groundwater recharge is an important part of the water resources evaluation. In spite of the numerous existing methods it continues to be not easy value to quantify. This is due to its dependence on many meteorological, hydrogeological, soil type and cover conditions and the impossibility for direct measurement. Employment of hydrological models in fact directly calculates the influence of the above cited natural factors. The Community Land Model (CLM3 being loaded with all land featuring data in global scale, including an adequate soil filtration process simulation by the Richards equation, together with the possibility for input of NCEP/NCAR Reanalyses database, featuring the meteorological effect, gives an opportunity to avoid to great extent the difficulties in groundwater (GW recharge estimation. The paper presents the results from an experiment concerning GW recharge monthly estimation during 2013, worked out for the Kamchia river watershed in Bulgaria. The computed monthly and annual values are presented on GIS maps and are compared with existing assessments made by other methods. It is proved the good approach and the applicability of the method.

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

    Science.gov (United States)

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

    2014-09-15

    Groundwater recharge using reclaimed water is considered a promising method to alleviate groundwater depletion, especially in arid areas. Traditional water treatment systems are inefficient to remove all the types of contaminants that would pose risks to groundwater, so it is crucial to establish a priority list of organic compounds (OCs) that deserve the preferential treatment. In this study, a comprehensive ranking system was developed to determine the list and then applied to China. 151 OCs, for which occurrence data in the wastewater treatment plants were available, were selected as candidate OCs. Based on their occurrence, exposure potential and ecological effects, two different rankings of OCs were established respectively for groundwater recharge by surface infiltration and direct aquifer injection. Thirty-four OCs were regarded as having no risks while the remaining 117 OCs were divided into three groups: high, moderate and low priority OCs. Regardless of the recharge way, nonylphenol, erythromycin and ibuprofen were the highest priority OCs; their removal should be prioritized. Also the database should be updated as detecting technology is developed. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Uncertainties in the simulation of groundwater recharge at different scales

    Directory of Open Access Journals (Sweden)

    H. Bogena

    2005-01-01

    Full Text Available Digital spatial data always imply some kind of uncertainty. The source of this uncertainty can be found in their compilation as well as the conceptual design that causes a more or less exact abstraction of the real world, depending on the scale under consideration. Within the framework of hydrological modelling, in which numerous data sets from diverse sources of uneven quality are combined, the various uncertainties are accumulated. In this study, the GROWA model is taken as an example to examine the effects of different types of uncertainties on the calculated groundwater recharge. Distributed input errors are determined for the parameters' slope and aspect using a Monte Carlo approach. Landcover classification uncertainties are analysed by using the conditional probabilities of a remote sensing classification procedure. The uncertainties of data ensembles at different scales and study areas are discussed. The present uncertainty analysis showed that the Gaussian error propagation method is a useful technique for analysing the influence of input data on the simulated groundwater recharge. The uncertainties involved in the land use classification procedure and the digital elevation model can be significant in some parts of the study area. However, for the specific model used in this study it was shown that the precipitation uncertainties have the greatest impact on the total groundwater recharge error.

  4. Episodic recharge and climate change in the Murray-Darling Basin, Australia

    Science.gov (United States)

    Crosbie, Russell S.; McCallum, James L.; Walker, Glen R.; Chiew, Francis H. S.

    2012-03-01

    In semi-arid areas, episodic recharge can form a significant part of overall recharge, dependant upon infrequent rainfall events. With climate change projections suggesting changes in future rainfall magnitude and intensity, groundwater recharge in semi-arid areas is likely to be affected disproportionately by climate change. This study sought to investigate projected changes in episodic recharge in arid areas of the Murray-Darling Basin, Australia, using three global warming scenarios from 15 different global climate models (GCMs) for a 2030 climate. Two metrics were used to investigate episodic recharge: at the annual scale the coefficient of variation was used, and at the daily scale the proportion of recharge in the highest 1% of daily recharge. The metrics were proportional to each other but were inconclusive as to whether episodic recharge was to increase or decrease in this environment; this is not a surprising result considering the spread in recharge projections from the 45 scenarios. The results showed that the change in the low probability of exceedance rainfall events was a better predictor of the change in total recharge than the change in total rainfall, which has implications for the selection of GCMs used in impact studies and the way GCM results are downscaled.

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

    Science.gov (United States)

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

    2009-01-01

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

  6. Assessing the recharge of a coastal aquifer using physical observations, tritium, groundwater chemistry and modelling.

    Science.gov (United States)

    Santos, Isaac R; Zhang, Chenming; Maher, Damien T; Atkins, Marnie L; Holland, Rodney; Morgenstern, Uwe; Li, Ling

    2017-02-15

    Assessing recharge is critical to understanding groundwater and preventing pollution. Here, we investigate recharge in an Australian coastal aquifer using a combination of physical, modelling and geochemical techniques. We assess whether recharge may occur through a pervasive layer of floodplain muds that was initially hypothesized to be impermeable. At least 59% of the precipitation volume could be accounted for in the shallow aquifer using the water table fluctuation method during four significant recharge events. Precipitation events recharge. The highest recharge rates were estimated in the area underneath the floodplain clay layer rather than in the sandy area. A steady-state chloride method implied recharge rates of at least 200mm/year (>14% of annual precipitation). Tritium dating revealed long term net vertical recharge rates ranging from 27 to 114mm/year (average 58mm/year) which were interpreted as minimum net long term recharge. Borehole experiments revealed more permeable conditions and heterogeneous infiltration rates when the floodplain soils were dry. Wet conditions apparently expand floodplain clays, closing macropores and cracks that act as conduits for groundwater recharge. Modelled groundwater flow paths were consistent with tritium dating and provided independent evidence that the clay layer does not prevent local recharge. Overall, all lines of evidence demonstrated that the coastal floodplain muds do not prevent the infiltration of rainwater into the underlying sand aquifer, and that local recharge across the muds was widespread. Therefore, assuming fine-grained floodplain soils prevent recharge and protect underlying aquifers from pollution may not be reasonable. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Gas and Gas Pains

    Science.gov (United States)

    ... Gas and gas pains Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

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

    Science.gov (United States)

    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.; hide

    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 degrees 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

  9. Precipitation Intensity Effects on Groundwater Recharge in the Southwestern United States

    Directory of Open Access Journals (Sweden)

    Brian F. Thomas

    2016-03-01

    Full Text Available Episodic recharge as a result of infrequent, high intensity precipitation events comprises the bulk of groundwater recharge in arid environments. Climate change and shifts in precipitation intensity will affect groundwater continuity, thus altering groundwater recharge. This study aims to identify changes in the ratio of groundwater recharge and precipitation, the R:P ratio, in the arid southwestern United States to characterize observed changes in groundwater recharge attributed to variations in precipitation intensity. Our precipitation metric, precipitation intensity magnification, was used to investigate the relationship between the R:P ratio and precipitation intensity. Our analysis identified significant changes in the R:P ratio concurrent with decreases in precipitation intensity. The results illustrate the importance of precipitation intensity in relation to groundwater recharge in arid regions and provide further insights for groundwater management in nonrenewable groundwater systems and in a changing climate.

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

    Science.gov (United States)

    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.

  11. Spatial distribution of groundwater recharge and base flow: Assessment of controlling factors

    Directory of Open Access Journals (Sweden)

    Z. Zomlot

    2015-09-01

    New hydrological insights for the region: The average resulting recharge is 235 mm/year and occurs mainly in winter. The overall moderate correlation between base flow estimates and modeled recharge rates indicates that base flow is a reasonable proxy of recharge. Groundwater recharge variation was explained in order of importance by precipitation, soil texture and vegetation cover; while base flow variation was strongly controlled by vegetation cover and groundwater depth. The results of this study highlight the important role of spatial variables in estimation of recharge and base flow. In addition, the prominent role of vegetation makes clear the potential importance of land-use changes on recharge and hence the need to include a proper strategy for land-use change in sustainable management of groundwater resources.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-28

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

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

    Science.gov (United States)

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

    2015-04-01

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

  14. Valuing groundwater recharge through agricultural production in the Hadejia-Nguru wetlands in northern Nigeria

    OpenAIRE

    Acharya, Gayatri; Barbier, Edward B.

    2000-01-01

    This study applies a production function approach to value the groundwater recharge function of the Hadejia-Nguru wetlands in northern Nigeria. The groundwater recharge function supports dry season agricultural production which is dependent on groundwater abstraction for irrigation. Using survey data this paper first carries out an economic valuation of agricultural production, per hectare of irrigated land. We then value the recharge function as an environmental input into the dry season agr...

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

    Science.gov (United States)

    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.

  16. Stochastic analysis of the recharge uncertainty of a regional aquifer in extreme arid conditions

    OpenAIRE

    Rojas, Rodrigo; Dassargues, Alain

    2006-01-01

    The Pampa del Tamarugal Aquifer (PTA) is an important source of groundwater in northern Chile. Since the study area is situated in the Atacama Desert, the estimation of groundwater recharge based on conventional hydrological methods is subject to large uncertainties. To account for variations in the groundwater balance, caused by uncertainties in the average recharge rates, randomly generated recharge values with different levels of uncertainty are simulated using a groundwater flow model. Re...

  17. Spatial distribution of groundwater recharge and base flow: Assessment of controlling factors

    OpenAIRE

    Z. Zomlot; B. Verbeiren; M. Huysmans; Batelaan, O.

    2015-01-01

    Study focus: Groundwater is of strategic importance. The accurate estimation of groundwater recharge and assessing the fundamental controlling factors are therefore of utmost importance to protect groundwater systems. We used the spatially-distributed water-balance model WetSpass to estimate long-term average recharge in Flanders. We validated recharge rates with base flow estimates of 67 daily stream flow records using the hydrograph analyses. To this end we performed principal component ana...

  18. Estimation of future groundwater recharge using climatic analogues and Hydrus-1D

    OpenAIRE

    B. Leterme; D. Mallants; Jacques, D.

    2012-01-01

    The impact of climate change on groundwater recharge is simulated using climatic analogue stations, i.e. stations presently under climatic conditions corresponding to a given climate state. The study was conducted in the context of a safety assessment of a future near-surface disposal facility for low and intermediate level short-lived radioactive waste in Belgium; this includes estimating groundwater recharge for the next millennia. Groundwater recharge was simulated using the Richard...

  19. A literature review of recharge estimation and groundwater resource assessment in Africa

    OpenAIRE

    Wang, Lei; O Dochartaigh, Brighid; MacDonald, David

    2010-01-01

    This report reviews the available literature on groundwater recharge and groundwater resource assessment in Africa. The purpose of this review is to identify estimates of groundwater recharge that have been undertaken either in Africa, or outside Africa but in similar environments and climates to those found in Africa. The first part of the report highlights the importance of groundwater recharge modelling to the study of climate change impacts on groundwater resources in Africa. Section 2...

  20. The aquifer recharge: an overview of the legislative and planning aspect.

    Science.gov (United States)

    De Giglio, O; Caggiano, G; Apollonio, F; Marzella, A; Brigida, S; Ranieri, E; Lucentini, L; Uricchio, V F; Montagna, M T

    2018-01-01

    In most regions of the world, safeguarding groundwater resources is a serious issue, particularly in coastal areas where groundwater is the main water source for drinking, irrigation and industry. Water availability depends on climate, topography and geology. The aim of this paper is to evaluate aquifer recharge as a possible strategy to relieve water resource scarcity. Natural aquifer recharge is defined as the downward flow of water reaching the water table, increasing the groundwater reservoir. Hydro-meteorological factors (rainfall, evapotranspiration and runoff) may alter natural recharge processes. Artificial aquifer recharge is a process by which surface water is introduced with artificial systems underground to fill an aquifer. As a consequence of global warming that has increased the frequency and severity of natural disasters like the drought, the impacts of climate change and seasonality, the artificial recharge has been considered as a viable option. Different direct and indirect techniques can be used, and the choice depends on the hydrologic characteristics of a specific area. In Italy, Legislative Decree no. 152/06 plans artificial aquifer recharge as an additional measure in water management, and Decree no. 100/2016 establishes quantitative and qualitative conditions for recharge. Many projects examine aquifer recharge, such us WADIS-MAR in the southern Mediterranean region, WARBO in Italy and municipal wastewater treatment project in Apulia, a southern Italian region. However, aside from groundwater recharge, the community must foster a spirit of cooperation to manage groundwater as a sustainable resource.

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

    Energy Technology Data Exchange (ETDEWEB)

    Savard, C.S.

    1998-10-01

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

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

    Science.gov (United States)

    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.

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

    National Research Council Canada - National Science Library

    Tillman, Fred D; 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...

  4. Deep rooted apple trees decrease groundwater recharge in the highland region of the Loess Plateau, China.

    Science.gov (United States)

    Zhang, Zhiqiang; Li, Min; Si, Bingcheng; Feng, Hao

    2018-05-01

    Unlike recharge in shallow rooted ecosystems, estimating the groundwater recharge beneath deep rooted plants that absorb water from deep soil remains difficult. The purpose of this research is to develop an approach to estimate the groundwater recharge beneath deep-rooted vegetation by combining water mass balance and chloride mass balance (CMB) and to quantify how the conversion of shallow-rooted cropland to deep-rooted apple orchards changes groundwater recharge. The proposed groundwater recharge rate under deep-rooted vegetation in this study is the difference between the groundwater recharge rate in a cropland (obtained using CMB) and the mean annual soil water storage deficit beneath an adjacent deep-rooted vegetation. The results show that the conversion from cropland (shallow-rooted) to apple orchard (deep-rooted) decreased soil water storage by 776, 1106, and 1117mm, corresponding to 19, 20, and 26-year-old apple orchards, respectively. Groundwater recharge beneath cropland, on average, was 58mmyr -1 , which amounts to 10% of the average annual precipitation. Groundwater recharge beneath the apple orchards were variable, but all being <3% of the average annual precipitation. The conversion of cropland to apple orchards lead to a substantial decrease in groundwater recharge, potentially threatening the sustainability of the land use change. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Managed Aquifer Recharge (MAR in Sustainable Urban Water Management

    Directory of Open Access Journals (Sweden)

    Declan Page

    2018-02-01

    Full Text Available To meet increasing urban water requirements in a sustainable way, there is a need to diversify future sources of supply and storage. However, to date, there has been a lag in the uptake of managed aquifer recharge (MAR for diversifying water sources in urban areas. This study draws on examples of the use of MAR as an approach to support sustainable urban water management. Recharged water may be sourced from a variety of sources and in urban centers, MAR provides a means to recycle underutilized urban storm water and treated wastewater to maximize their water resource potential and to minimize any detrimental effects associated with their disposal. The number, diversity and scale of urban MAR projects is growing internationally due to water shortages, fewer available dam sites, high evaporative losses from surface storages, and lower costs compared with alternatives where the conditions are favorable, including water treatment. Water quality improvements during aquifer storage are increasingly being documented at demonstration sites and more recently, full-scale operational urban schemes. This growing body of knowledge allows more confidence in understanding the potential role of aquifers in water treatment for regulators. In urban areas, confined aquifers provide better protection for waters recharged via wells to supplement potable water supplies. However, unconfined aquifers may generally be used for nonpotable purposes to substitute for municipal water supplies and, in some cases, provide adequate protection for recovery as potable water. The barriers to MAR adoption as part of sustainable urban water management include lack of awareness of recent developments and a lack of transparency in costs, but most importantly the often fragmented nature of urban water resources and environmental management.

  6. Artificial recharge through a thick, heterogeneous unsaturated zone

    Science.gov (United States)

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

    2008-01-01

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

  7. Representative recharge rates in a complex unsaturated hydrogeology

    Energy Technology Data Exchange (ETDEWEB)

    Vold, E.; Newman, B.; Birdsell, K. [and others

    1997-02-01

    This study summarizes analyses used for the determination of representative recharge rates in a semi-arid terrain of complex topography for the purpose of modeling the performance assessment of a mesa top disposal facility. Four recharge rates are identified based on different terrains. The terrain is first broadly grouped into canyon bottoms and mesa tops, with each covering about half the topography. The canyon bottoms are considered wet or dry depending on the local infiltration conditions and the influence of mans` activities. The mesa tops are separated into locations which are undisturbed and disturbed by laboratory operations. Disturbed locations at the disposal facility include the disposal pits utilized for shallow land burial of low-level radioactive waste, covering approximately half the mesa top area. Several sources of data and analyses have been synthesized to estimate the resulting recharge rates. Data and analyses include: (1) detailed surface water balance calculations with site-specific parameter values as input; (2) chloride ion profiles and analysis of implied flux at several borehole locations; (3) analyses of liquid and vapor phase vertical flux from moisture profiles with stratigraphic unit averaged unsaturated hydrologic properties; (4) comparison of moisture content field data with values implied from Darcy flux calculations for assumed unit gradient conditions and for stratigraphic unit averaged unsaturated hydrologic properties; (5) liquid flux calculated under self-consistent gradients from field observed moisture profiles and analytic determinations of in-situ moisture potential and conductivity at limited locations; (6) distributions in near surface soil moisture contents expressed as an equivalent vertical flux under unit gradient assumptions; and (7) limited comparisons to tracers available from past disposal operations.

  8. Characterizing Heterogeneity in Infiltration Rates During Managed Aquifer Recharge.

    Science.gov (United States)

    Mawer, Chloe; Parsekian, Andrew; Pidlisecky, Adam; Knight, Rosemary

    2016-11-01

    Infiltration rate is the key parameter that describes how water moves from the surface into a groundwater aquifer during managed aquifer recharge (MAR). Characterization of infiltration rate heterogeneity in space and time is valuable information for MAR system operation. In this study, we utilized fiber optic distributed temperature sensing (FO-DTS) observations and the phase shift of the diurnal temperature signal between two vertically co-located fiber optic cables to characterize infiltration rate spatially and temporally in a MAR basin. The FO-DTS measurements revealed spatial heterogeneity of infiltration rate: approximately 78% of the recharge water infiltrated through 50% of the pond bottom on average. We also introduced a metric for quantifying how the infiltration rate in a recharge pond changes over time, which enables FO-DTS to be used as a method for monitoring MAR and informing maintenance decisions. By monitoring this metric, we found high-spatial variability in how rapidly infiltration rate changed during the test period. We attributed this variability to biological pore clogging and found a relationship between high initial infiltration rate and the most rapid pore clogging. We found a strong relationship (R2  = 0.8) between observed maximum infiltration rates and electrical resistivity measurements from electrical resistivity tomography data taken in the same basin when dry. This result shows that the combined acquisition of DTS and ERT data can improve the design and operation of a MAR pond significantly by providing the critical information needed about spatial variability in parameters controlling infiltration rates. © 2016, National Ground Water Association.

  9. High pressure water electrolysis for space station EMU recharge

    Science.gov (United States)

    Lance, Nick; Puskar, Michael; Moulthrop, Lawrence; Zagaja, John

    1988-01-01

    A high pressure oxygen recharge system (HPORS), is being developed for application on board the Space Station. This electrolytic system can provide oxygen at up to 6000 psia without a mechanical compressor. The Hamilton standard HPORS based on a solid polymer electrolyte system is an extension of the much larger and succesful 3000 psia system of the U.S. Navy. Cell modules have been successfully tested under conditions beyond which spacecraft may encounter during launch. The control system with double redundancy and mechanical backups for all electronically controlled components is designed to ensure a safe shutdown.

  10. Modeling of an electrically rechargeable alkaline zinc-air battery

    Energy Technology Data Exchange (ETDEWEB)

    Deiss, E.; Holzer, F.; Haas, O.

    2003-03-01

    A numerical model has been developed to simulate the charging and discharge behaviour of an electrically rechargeable alkaline zinc-air battery. Further a galvanostatic experiment including three charge/discharge cycles has been performed. The cell voltages, the Zn electrode potentials versus a Zn reference, and the O{sub 2} electrode potentials versus a Zn reference calculated with the model are in fairly good agreement with the corresponding experimental data. The model is expected to be useful for zinc-air battery design and for analysis of experimental data. (author)

  11. Damage Control Plan for International Space Station Recharge Tank Assembly Composite Overwrapped Pressure Vessel

    Science.gov (United States)

    Cook, Anthony J.

    2011-01-01

    As NASA has retired the Space Shuttle Program, a new method of transporting compressed gaseous nitrogen and oxygen needed to be created for delivery of these crucial life support resources to the International Space Station (ISS). One of the methods selected by NASA includes the use of highly pressurized, unprotected Recharge Tank Assemblies (RTAs) utilizing Composite Overwrapped Pressure Vessels (COPVs). A COPV consists of a thin liner wrapped with a fiber composite and resin or epoxy. It is typically lighter weight than an all metal pressure vessel of similar volume and therefore provides a higher-efficiency means for gas storage. However COPVs are known to be susceptible to damage resulting from handling, tool drop impacts, or impacts from other objects. As a result, a comprehensive Damage Control Plan has been established to mitigate damage to the RTA COPV throughout its life cycle. The DCP is intended to evaluate and mitigate defined threats during manufacturing, shipping and handling, test, assembly level integration, shipment while pressurized, launch vehicle integration and mission operations by defining credible threats and methods for preventing potential damage while still maintaining the primary goal of resupplying ISS gas resources. A comprehensive threat assessment is performed to identify all threats posed to the COPV during the different phases of its lifecycle. The threat assessment is then used as the basis for creating a series of general inspection, surveillance and reporting requirements which apply across all phases of the COPV's life, targeted requirements only applicable to specific work phases and a series of training courses for both ground personnel and crew aboard the ISS. A particularly important area of emphasis deals with creating DCP requirements for a highly pressurized, large and unprotected RTA COPV for use during Inter Vehicular Activities (IVA) operations in the micro gravity environment while supplying pressurized gas to the

  12. Ground-water recharge in Escambia and Santa Rosa Counties, Florida

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 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 reconstruct location-specific recharge histories in fractured porous rock aquifers. The proposed approach can be applied worldwide at sites with similar climatic and geologic characteristics.

  14. Linking denitrification and infiltration rates during managed groundwater recharge.

    Science.gov (United States)

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

    2011-11-15

    We quantify relations between rates of in situ denitrification and saturated infiltration through shallow, sandy soils during managed groundwater recharge. We used thermal methods to determine time series of point-specific flow rates, and chemical and isotopic methods to assess denitrification progress. Zero order denitrification rates between 3 and 300 μmol L(-1) d(-1) were measured during infiltration. Denitrification was not detected at times and locations where the infiltration rate exceeded a threshold of 0.7 ± 0.2 m d(-1). Pore water profiles of oxygen and nitrate concentration indicated a deepening of the redoxocline at high flow rates, which reduced the thickness of the zone favorable for denitrification. Denitrification rates were positively correlated with infiltration rates below the infiltration threshold, suggesting that for a given set of sediment characteristics, there is an optimal infiltration rate for achieving maximum nitrate load reduction and improvements to water supply during managed groundwater recharge. The extent to which results from this study may be extended to other managed and natural hydrologic settings remains to be determined, but the approach taken in this study should be broadly applicable, and provides a quantitative link between shallow hydrologic and biogeochemical processes.

  15. Natural water purification and water management by artificial groundwater recharge.

    Science.gov (United States)

    Balke, Klaus-Dieter; Zhu, Yan

    2008-03-01

    Worldwide, several regions suffer from water scarcity and contamination. The infiltration and subsurface storage of rain and river water can reduce water stress. Artificial groundwater recharge, possibly combined with bank filtration, plant purification and/or the use of subsurface dams and artificial aquifers, is especially advantageous in areas where layers of gravel and sand exist below the earth's surface. Artificial infiltration of surface water into the uppermost aquifer has qualitative and quantitative advantages. The contamination of infiltrated river water will be reduced by natural attenuation. Clay minerals, iron hydroxide and humic matter as well as microorganisms located in the subsurface have high decontamination capacities. By this, a final water treatment, if necessary, becomes much easier and cheaper. The quantitative effect concerns the seasonally changing river discharge that influences the possibility of water extraction for drinking water purposes. Such changes can be equalised by seasonally adapted infiltration/extraction of water in/out of the aquifer according to the river discharge and the water need. This method enables a continuous water supply over the whole year. Generally, artificially recharged groundwater is better protected against pollution than surface water, and the delimitation of water protection zones makes it even more save.

  16. Decision Support System for Aquifer Recharge (AR) and ...

    Science.gov (United States)

    Aquifer recharge (AR) is a technical method being utilized to enhance groundwater resources through man-made replenishment means, such as infiltration basins and injections wells. Aquifer storage and recovery (ASR) furthers the AR techniques by withdrawal of stored groundwater at a later time for beneficial use. It is a viable adaptation technique for water availability problems. Variants of the water storage practices include recharge through urban green infrastructure and the subsurface injection of reclaimed water, i.e., wastewater, which has been treated to remove solids and impurities. In addition to a general overview of ASR variations, this report focuses on the principles and technical basis for an ASR decision support system (DSS), with the necessary technical references provided. The DSS consists of three levels of tools and methods for ASR system planning and assessment, design, and evaluation. Level 1 of the system is focused on ASR feasibility, for which four types of data and technical information are organized around: 1) ASR regulations and permitting needs, 2) Water demand projections, 3) Climate change and water availability, and 4) ASR sites and technical information. These technical resources are integrated to quantify water availability gaps and the feasibility of using ASR to meet the volume and timing of the water resource shortages. A systemic analysis of water resources was conducted for sustainable water supplies in Las Vegas, Nevada f

  17. Development and commercialisation of rechargeable wooden LED lamps

    Directory of Open Access Journals (Sweden)

    Bradley Schultz

    2013-02-01

    Full Text Available The focus of this project was to work with local staff at Kathmandu Alternative Power and Energy Group to commercialise a product which would generate recurring income for the organisation, to enable staff to learn the process of commercialisation and to provide employment and skills in the local community. Rechargeable Light Emitting Diode (LED lamps were deemed suitable for these aims, as they are a simple product, yet one that is urgently required in Nepal due to the prevalence of ‘load-shedding’ – scheduled electrical blackouts. After reviewing the market, it was found that it would be impossible to compete with the price of cheap imported Chinese rechargeable LED lamps, so an alternative approach was taken. This involved sourcing wooden off-cuts from a local furniture factory and transforming them into attractive desk lamps, with the target market being affluent Nepalis, ex-pats living in Nepal and tourists. Successful initial sales were achieved through a Kathmandu-based ex-pat email group, hotel-markets and souvenir stores. KAPEG staff have continued the project, producing variations on the initial design including Himalayan rock salt lamps, employing local people to manufacture lamps and selling them at markets in Kathmandu. Staffing and marketing challenges remain to ensure the lamp manufacture and sales continue.

  18. Reconnaissance Estimates of Recharge Based on an Elevation-dependent Chloride Mass-balance Approach

    Energy Technology Data Exchange (ETDEWEB)

    Charles E. Russell; Tim Minor

    2002-08-31

    Significant uncertainty is associated with efforts to quantity recharge in arid regions such as southern Nevada. However, accurate estimates of groundwater recharge are necessary to understanding the long-term sustainability of groundwater resources and predictions of groundwater flow rates and directions. Currently, the most widely accepted method for estimating recharge in southern Nevada is the Maxey and Eakin method. This method has been applied to most basins within Nevada and has been independently verified as a reconnaissance-level estimate of recharge through several studies. Recharge estimates derived from the Maxey and Eakin and other recharge methodologies ultimately based upon measures or estimates of groundwater discharge (outflow methods) should be augmented by a tracer-based aquifer-response method. The objective of this study was to improve an existing aquifer-response method that was based on the chloride mass-balance approach. Improvements were designed to incorporate spatial variability within recharge areas (rather than recharge as a lumped parameter), develop a more defendable lower limit of recharge, and differentiate local recharge from recharge emanating as interbasin flux. Seventeen springs, located in the Sheep Range, Spring Mountains, and on the Nevada Test Site were sampled during the course of this study and their discharge was measured. The chloride and bromide concentrations of the springs were determined. Discharge and chloride concentrations from these springs were compared to estimates provided by previously published reports. A literature search yielded previously published estimates of chloride flux to the land surface. {sup 36}Cl/Cl ratios and discharge rates of the three largest springs in the Amargosa Springs discharge area were compiled from various sources. This information was utilized to determine an effective chloride concentration for recharging precipitation and its associated uncertainty via Monte Carlo simulations

  19. B-10 enriched boric acid, bromide, and heat as tracers of recycled groundwater flow near managed aquifer recharge operations

    Science.gov (United States)

    Clark, J. F.; Becker, T.; Johnson, T. A.

    2013-12-01

    Recycling wastewater for potable and nonpotable use by artificially recharging aquifers is a decades-old but increasingly popular practice. Natural attenuation processes in the subsurface, known as soil aquifer treatment (SAT), purify recycled water during recharge and subsequent groundwater flow. Travel time criteria are often used to regulate managed aquifer recharge (MAR) operations. California state draft regulations currently gives preference to groundwater tracers to quantify underground residence time, with a target retention time of >6 months from infiltration to drinking water extraction for surface spreading projects using tertiary treated wastewater (less time may be possible if full advanced treated water is utilized). In the past sulfur hexafluoride, a very strong greenhouse gas, has been the principle deliberate tracer for this work. However, its emission has recently become regulated in California and new tracers are needed. Here, two prospective tracers are evaluated: boron-10 (B-10), the least abundant boron isotope, and heat (with recharging water naturally warmed at the sewage treatment plants and in surface-spreading basins). An additional deliberate tracer, bromide (Br), which is a well-studied conservative tracer, was released as a control. Tracer injection occurred at the San Gabriel Spreading Grounds research test basin in Los Angeles County, CA, USA. The basin was constructed and characterized by the US Geological Survey in the mid-1990s. Recycled wastewater was piped directly to this basin at a known rate (about 1.5 m3/day). Down gradient from the test basin are nine high quality monitoring wells in a line that extends from the center of the basin to 150 m down gradient. All of the wells were equipped with temperature loggers that recorded groundwater temperatures every hour with an accuracy of one thousandth of a degree. The pre-experiment expected arrival times ranged from less than one day to six months. Arrival of Br was always

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, Joseph C.

    2017-06-27

    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.

  2. Atlantis Water Supply Scheme (AWSS) artificial recharge scientific and operational support

    CSIR Research Space (South Africa)

    Jovanovic, Nebojsa

    2012-10-01

    Full Text Available , Stellenbosch, South Africa 2City of Cape Town, South Africa CSIR, PO Box 395, Pretoria, South Africa, 0001 Email: njovanovic@csir.co.za ? www.csir.co.za WHAT IS MANAGED AQUIFER RECHARGE? Managed Aquifer Recharge (MAR) is defined by the transfer of surface...

  3. MODIS-aided statewide net groundwater-recharge estimation in Nebraska.

    Science.gov (United States)

    Szilagyi, Jozsef; Jozsa, Janos

    2013-01-01

    Monthly evapotranspiration (ET) rates (2000 to 2009) across Nebraska at about 1-km resolution were obtained by linear transformations of the MODIS (MODerate resolution Imaging Spectroradiometer) daytime surface temperature values with the help of the Priestley-Taylor equation and the complementary relationship of evaporation. For positive values of the mean annual precipitation and ET differences, the mean annual net recharge was found by an additional multiplication of the power-function-transformed groundwater vulnerability DRASTIC-code values. Statewide mean annual net recharge became about 29 mm (i.e., 5% of mean annual precipitation) with the largest recharge rates (in excess of 100 mm/year) found in the eastern Sand Hills and eastern Nebraska. Areas with the largest negative net recharge rates caused by declining groundwater levels due to large-scale irrigation are found in the south-western region of the state. Error bounds of the estimated values are within 10% to 15% of the corresponding precipitation rates and the estimated net recharge rates are sensitive to errors in the precipitation and ET values. This study largely confirms earlier base-flow analysis-based statewide groundwater recharge estimates when considerations are made for differences in the recharge definitions. The current approach not only provides better spatial resolution than available earlier studies for the region but also quantifies negative net recharge rates that become especially important in numerical modeling of shallow groundwater systems. © 2012, The Author(s). Groundwater © 2012, National Ground Water Association.

  4. A ROOT ZONE MODELLING APPROACH TO ESTIMATING GROUNDWATER RECHARGE FROM IRRIGATED AREAS

    Science.gov (United States)

    In irrigated semi-arid and arid regions, accurate knowledge of groundwater recharge is important for the sustainable management of scarce water resources. The Campo de Cartagena area of southeast Spain is a semi-arid region where irrigation return flow accounts for a substantial portion of recharge....

  5. Groundwater Recharge Estimation And Water Resources Assessment In A Tropical Crystalline Basement Aquifer

    NARCIS (Netherlands)

    Nyagwambo, N.L.

    2006-01-01

    While most groundwater recharge estimation methods give reasonable long-term annual average estimates very few if any methods offer guidance on monthly recharge. In crystalline basement aquifers (CBAs) the problem is compounded by the high seasonal, intra-annual and inter-annual variability. The

  6. Groundwater Diffuse Recharge and its Response to Climate Changes in Semi-Arid Northwestern China

    Directory of Open Access Journals (Sweden)

    Lin Deng

    2015-01-01

    Full Text Available Understanding the processes and rates of groundwater recharge in arid and semi-arid areas is crucial for utilizing and managing groundwater resources sustainably. We obtained three chloride profiles of the unsaturated-zone in the desert/loess transition zone of northwestern China and reconstructed the groundwater recharge variations over the last 11, 21, and 37 years, respectively, using the generalized chloride mass balance (GCMB method. The average recharge rates were 43.7, 43.5, and 45.1 mm yr-1, respectively, which are similar to those evaluated by the chloride mass balance (CMB or GCMB methods in other semi-arid regions. The results indicate that the annual recharge rates were not in complete linear proportion to the corresponding annual precipitations, although both exhibited descending tendencies on the whole. Comparisons between the daily precipitation aggregate at different intensity and recharge rates reveal that the occurrence of relatively heavy daily precipitation per year may contribute to such nonlinearity between annual precipitation and recharge. The possible influences of vegetation cover alterations following precipitation change cannot be excluded as well. The approximately negative correlation between the average annual recharge and temperature suggests that changes in temperature have had significant influences on recharge.

  7. Recharge Rates and Chemistry Beneath Playas of the High Plains Aquifer - A Literature Review and Synthesis

    Science.gov (United States)

    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.

  8. Evaluation of Universitas Indonesia’s Recharge Pond Performance and Potential Utilization for Raw Water Source

    Directory of Open Access Journals (Sweden)

    Nyoman Suwartha

    2012-05-01

    Full Text Available The UI recharge pond has been constructed 5 years ago. However, monitoring and evaluation activities on its performances are very lack. Aims of this study are to understand the recharge rate, and to evaluate existing quantity and water quality of the pond during dry and rainy season. Measurement of water depth, rainfall intensity, and evaporation is conducted to determine water availability, recharge rate, and water balance of the recharge pond. Amount of surface water is collected from recharge pond and river at three sampling point to determine existing water quality of the pond. The results showed that recharge rate of the pond between dry season (3.2 mm/day and wet season (6.1 mm/day are considered as insignificant different. The water balance of the recharge pond shows an excessive rate. Various physics and chemical parameters (turbidity, color, TDS, pH, and  Cl are found to have concentration lower than the water quality standard. The results suggest that the pond surface water is remain suitable to be recharged into aquifer zone so that sustaining ground water conservation campaign, and it is potential to be utilized as an additional  raw water source for domestic water demand of UI Campus Depok.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-01-01

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

  12. Groundwater Recharge in Irrigated Agriculture: The Theory and Practice of Inverse Modelling

    NARCIS (Netherlands)

    Boonstra, J.; Bhutta, M.N.

    1996-01-01

    Quantifying the rate of natural groundwater recharge is a prerequisite for drainage design in waterlogged areas. The present study was aimed at determining the seasonal net recharge in the Schedule I-B area of the Fourth Drainage Project, Faisalabad, Pakistan. A numerical groundwater model was

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

    Science.gov (United States)

    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.

  14. Estimation of Groundwater Recharges Using Empirical Formulae in Odeda Local Government Area, Ogun State, Nigeria

    Directory of Open Access Journals (Sweden)

    Oluseyi O. Adeleke

    2015-11-01

    Full Text Available Estimation and forecast of groundwater recharge and capacities of aquifers are essential issues in water resource investigation. In the current research, groundwater recharge and the recharge coefficient were determined through a case study using empirical methods applicable to the tropical zones. The related climatological data between January 1983 and December 2014 were collected in Ogun-Oshun River Basin Development Authority (OORBDA, Ogun State, Nigeria. The results showed that groundwater recharge was 194.7 mm per year, evapotranspiration was 1296.2 mm per year, and the recharge coefficient was 20.2% for the study area. The result showed that about 11% of rainfall infiltrated the aquifer, 73% was loss to evapotranspiration, and 36% ended up as run-off. Correlation between climatic parameters and groundwater recharge showed the highest correlation between recharge and rainfall. Temperature, humidity, solar radiation and evapotranspiraton were at the 0.01 significance level, and the results of linear regressions proved that precipitation has a significant effect (with R2 = 0.983 on estimated recharge.

  15. Enhancement of wadi recharge using dams coupled with aquifer storage and recovery wells

    KAUST Repository

    Missimer, Thomas M. M.

    2014-06-25

    Wadi channel recharge to the underlying alluvial aquifer is naturally limited by the flashy nature of flood events, evapotranspiration losses of water from the vadose zone, and aquifer heterogeneity, particularly low vertical hydraulic conductivity. Anthropogenic lowering of the water table in many wadi aquifers has also reduced the potential recharge by increasing the thickness of the vadose zone, causing interflow water loss from surface emergence and evaporation. A method to enhance recharge is to slow the flow within wadi channels by placement of dam structures, thereby ponding water and increasing the vertical head gradient to create a more rapid rate of infiltration and percolation. Effectiveness of wadi dams to enhance aquifer recharge reduces over time due to mud deposition within the reservoir caused by storm events. Up to 80 % of the water in old wadi reservoirs is lost to free-surface evaporation before infiltration and recharge can occur. One method to maintain or increase the rate of recharge is to convey clean water by gravity flow from the reservoir down-gradient to artificially recharge the aquifer using existing wells. This type of system is a low-cost and low-energy recharge method which could greatly enhance groundwater storage in wadi aquifers. Modeling results show that existing wells could store up to 1,000 m3/day under gravity-feed conditions and up to 3,900 m3/day with the shut-in of the well to produce a pressurized system. © 2014 Springer-Verlag Berlin Heidelberg.

  16. Climate Impact on Groundwater Recharge in Southeastern Louisiana and Southwestern Mississippi

    Science.gov (United States)

    Beigi, E.; Tsai, F. T.

    2012-12-01

    Increases of concentrations of CO2 and other greenhouse gases have a significant effect on global climate, precipitation and hydrology, which in turn influences recharge to aquifers. Groundwater recharge study is imperative to the sole source aquifer, for example the Southern Hills aquifer system in southeastern Louisiana and southwestern Mississippi, which provides more than 50 percent of the drinking water consumed in the area overlying the aquifer and has no substitute drinking water source(s). To trace the climate impact and its consequent groundwater availability, this study developed a GIS-based integrated framework to connect climate models to a high-resolution hydrologic model to quantify long-term groundwater recharge. We employed the Hydrologic Evaluation of Landfill Performance (HELP3) model as our hydrologic model to estimate spatial-temporal distribution of potential recharge for a regional scale. HELP3 model was especially suitable for our recharge study due to Louisiana humid climate and the use of a regional-scale water budget approach. Detailed surficial soil property and land cover were obtained from the NRCS and the USGS to derive maps of curve number for the HELP3 model. Wireline well logs and drillers logs were analyzed to determine stratigraphic lithology and the first major sand encountered beneath the soil layer. For a regional scale, we used global circulation model (GCM) downscaled daily precipitation and temperature obtained from USGS CASCaDE Project Climate Data as the forcing input to the HELP3 model. The emission scenarios considered in this study were A2, B1 and A1FI from Parallel Climate Model 1 (PCM) and from the NOAA Geophysical Fluid Dynamics Lab's GFDL CM2.1 model. We used the computed runoff from USGS WaterWatch along with the HELP3 model to calculate the recharge index (RI) and delineate the recharge index map for individual hydrologic units in terms of Hydrologic Unit Codes (HUCs). The recharge index was defined as the

  17. 1:750,000-scale hydrographic areas and basin-wide pumpage, recharge and interbasin flow estimates of Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of the administrative hydrographic area (HA) boundaries for Nevada at 1:750,000-scale and estimates of natural recharge, artificial recharge,...

  18. Pathogen Decay during Managed Aquifer Recharge at Four Sites with Different Geochemical Characteristics and Recharge Water Sources.

    Science.gov (United States)

    Sidhu, J P S; Toze, S; Hodgers, L; Barry, K; Page, D; Li, Y; Dillon, P

    2015-09-01

    Recycling of stormwater water and treated effluent via managed aquifer recharge (MAR) has often been hampered because of perceptions of low microbiological quality of recovered water and associated health risks. The goal of this study was to assess the removal of selected pathogens in four large-scale MAR schemes and to determine the influence of aquifer characteristics, geochemistry, and type of recharge water on the pathogen survival times. Bacterial pathogens tested in this study had the shortest one log removal time (, 200 d). Human adenovirus and rotavirus were relatively persistent under anaerobic conditions (, >200 d). Human adenovirus survived longer than all the other enteric virus tested in the study and hence could be used as a conservative indicator for virus removal in groundwater during MAR. The results suggest that site-specific subsurface conditions such as groundwater chemistry can have considerable influence on the decay rates of enteric pathogens and that viruses are likely to be the critical pathogens from a public health perspective. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  19. Groundwater recharge to the Gulf Coast aquifer system in Montgomery and Adjacent Counties, Texas

    Science.gov (United States)

    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.

  20. Geochemical Signature of Natural Water Recharge in the Jungar Basin and Its Response to Climate.

    Science.gov (United States)

    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.

  1. Electrochemical characterization of Fe-air rechargeable oxide battery in planar solid oxide cell stacks

    Science.gov (United States)

    Fang, Qingping; Berger, Cornelius M.; Menzler, Norbert H.; Bram, Martin; Blum, Ludger

    2016-12-01

    Iron-air rechargeable oxide batteries (ROB) comprising solid oxide cells (SOC) as energy converters and Fe/metal-oxide redox couples were characterized using planar SOC stacks. The charge and discharge of the battery correspond to the operations in the electrolysis and fuel cell modes, respectively, but with a stagnant atmosphere consisting of hydrogen and steam. A novel method was employed to establish the stagnant atmosphere for battery testing during normal SOC operation without complicated modification to the test bench and stack/battery concept. Manipulation of the gas compositions during battery operation was not necessary, but the influence of the leakage current from the testing system had to be considered. Batteries incorporating Fe2O3/8YSZ, Fe2O3/CaO and Fe2O3/ZrO2 storage materials were characterized at 800 °C. A maximum charge capacity of 30.4 Ah per layer (with an 80 cm2 active cell area) with ∼0.5 mol Fe was reached with a current of 12 A. The charge capacity lost 11% after ∼130 ROB cycles due to the increased agglomeration of active materials and formation of a dense oxide layer on the surface. The round trip efficiencies of the tested batteries were ≤84% due to the large internal resistance. With state-of-the-art cells, the round trip efficiency can be further improved.

  2. Groundwater recharge of carbonate aquifers of the Silesian-Cracow Triassic (southern Poland) under human impact

    Science.gov (United States)

    Kowalczyk, Andrzej; Witkowski, Andrzej J.

    2008-07-01

    A Triassic carbonate unit has been intensively drained by zinc and lead ore mines and numerous borehole fields since the nineteenth century. Its groundwater recharge has increased due to: pumping of water from boreholes, mining activity, and urbanization. An approach to determine the amounts of the recharge at a variety of spatial scales is presented in the paper. Different methods were used to identify and quantify recharge components on a regional and local scale: mathematical modelling was performed for four aquifers included in an aquifer system, an analytical estimation based on the assumption that an average recharge is equal to the average discharge of the hydrogeological system—for six man-made drainage centres, and the method of water level fluctuation (WLF) was applied in one observation borehole. Results of modelling have been supplemented by observation of environmental tracers (δ18O, δ2H, 3H), noble gases temperatures, and 4Heexc in groundwater. The regional aquifer’s current recharge according to estimations performed by means of modelling varies from 39 to 101 mm/year on average. Depending on the aquifer site the average precipitation ranges from 779 to 864 mm/year. In the confined part of the aquifer average recharge ranges from 26 to 61 mm/year. Within outcrops average recharge varies from 96 to 370 mm/year. Current recharge estimated by the analytical method for man-made drainage centres varies from 158 up to 440 mm/year. High values are caused by different recharge sources like precipitation, induced leakage from shallow aquifers, and water losses from streams, water mains and sewer systems. Pumping of water, mining and municipal activities constitute additional factors accounting for the intensified recharge.

  3. Temporal and spatial variability of groundwater recharge on Jeju Island, Korea

    Science.gov (United States)

    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.

  4. Quantification of groundwater recharge in a hard rock terrain of Orissa: a case study.

    Science.gov (United States)

    Sethi, Ranu Rani; Kumar, A; Sharma, S P

    2009-01-01

    A study was carried out to select the best method to estimate groundwater recharge in a hard rock terrain. Various standard empirical methods, soil-moisture balance method, water table fluctuation (WTF) method and commonly adopted norms set by Groundwater Estimation Committee (GEC), Govt of India were used to estimate recharge for the Munijhara watershed in the Nayagarh block of Orissa (India). The empirical formulae gave recharge rates ranging from 13 cm to 32 cm/year with average of 22.4 cm and standard deviation of 5.34, independent of other influencing factors like soil, topography and geology. The soil-moisture balance study indicated that recharge is more dependent on the continuous heavy rainfall total annual volume of rainfall. Recharge was limited at up to 10 mm per day, possibly due to presence of hard rock below the soil surface. The rise in water table depth was 3.45 m to 5.35 m with a mean rise of 4.5 m during the year 2006-2007. Annual groundwater recharge based on the WTF approach varied from 10.3 to 16.85 cm with a mean of 13.5 cm, standard deviation of 1.57 cm and coefficient of variation 11.57%. This recharge accounted for 8 to 14% of rainfall received. With a water budget approach based on GEC norms, recharge was calculated as 17 cm per year. The study showed that the magnitudes of annual groundwater recharge as estimated by the WST method and GEC norms are in conformity with other recent findings in India under the same climate conditions. Based on the results recharge structures could be planned in suitable locations to reduce fallow areas under the watershed.

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

    Science.gov (United States)

    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 (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.

  6. Use of Constructed Wetlands for Polishing Recharge Wastewater

    Science.gov (United States)

    Cardwell, W.

    2009-12-01

    The use of constructed wetlands for waste water treatment is becoming increasingly popular as more focus is being shifted to natural means of waste treatment. These wetlands employ processes that occur naturally and effectively remove pollutants and can greatly minimize costs when compared to full scale treatment plants. Currently, wetland design is based on basic “rules-of-thumb,” meaning engineers have a general understanding but not necessarily a thorough knowledge of the intricate physical, biological, and chemical processes involved in these systems. Furthermore, there is very little consideration given to use the wetland as a recharge pond to allow the treated water to percolate and recharge the local groundwater aquifers. The City of Foley, located in Alabama, and the Utilities Board of the City of Foley partnered with Wolf Bay Watershed Watch to evaluate alternative wastewater effluent disposal schemes. Rather than discharging the treated water into a local stream, a pilot program has been developed to allow water from the treatment process to flow into a constructed wetlands area where, after natural treatment, the treated water will then be allowed to percolate into a local unconfined aquifer. The goal of this study is to evaluate how constructed wetlands can be used for “polishing” effluent as well as how this treated water might be reused. Research has shown that constructed wetlands, with proper design and construction elements, are effective in the treatment of BOD, TSS, nitrogen, phosphorous, pathogens, metals, sulfates, organics, and other substances commonly found in wastewater. Mesocosms will be used to model the wetland, at a much smaller scale, in order to test and collect data about the wetland treatment capabilities. Specific objectives include: 1. Determine optimum flow rates for surface flow wetlands where water treatment is optimized. 2. Evaluate the capabilities of constructed wetlands to remove/reduce common over the counter

  7. Noble gas signatures in the Island of Maui, Hawaii: Characterizing groundwater sources in fractured systems

    Science.gov (United States)

    Niu, Yi; Castro, M. Clara; Hall, Chris M.; Gingerich, Stephen B.; Scholl, Martha A.; Warrier, Rohit B.

    2017-01-01

    Uneven distribution of rainfall and freshwater scarcity in populated areas in the Island of Maui, Hawaii, renders water resources management a challenge in this complex and ill-defined hydrological system. A previous study in the Galapagos Islands suggests that noble gas temperatures (NGTs) record seasonality in that fractured, rapid infiltration groundwater system rather than the commonly observed mean annual air temperature (MAAT) in sedimentary systems where infiltration is slower thus, providing information on recharge sources and potential flow paths. Here we report noble gas results from the basal aquifer, springs, and rainwater in Maui to explore the potential for noble gases in characterizing this type of complex fractured hydrologic systems. Most samples display a mass-dependent depletion pattern with respect to surface conditions consistent with previous observations both in the Galapagos Islands and Michigan rainwater. Basal aquifer and rainwater noble gas patterns are similar and suggest direct, fast recharge from precipitation to the basal aquifer. In contrast, multiple springs, representative of perched aquifers, display highly variable noble gas concentrations suggesting recharge from a variety of sources. The distinct noble gas patterns for the basal aquifer and springs suggest that basal and perched aquifers are separate entities. Maui rainwater displays high apparent NGTs, incompatible with surface conditions, pointing either to an origin at high altitudes with the presence of ice or an ice-like source of undetermined origin. Overall, noble gas signatures in Maui reflect the source of recharge rather than the expected altitude/temperature relationship commonly observed in sedimentary systems.

  8. Noble gas signatures in the Island of Maui, Hawaii: Characterizing groundwater sources in fractured systems

    Science.gov (United States)

    Niu, Yi; Castro, M. Clara; Hall, Chris M.; Gingerich, Stephen B.; Scholl, Martha A.; Warrier, Rohit B.

    2017-05-01

    Uneven distribution of rainfall and freshwater scarcity in populated areas in the Island of Maui, Hawaii, renders water resources management a challenge in this complex and ill-defined hydrological system. A previous study in the Galapagos Islands suggests that noble gas temperatures (NGTs) record seasonality in that fractured, rapid infiltration groundwater system rather than the commonly observed mean annual air temperature (MAAT) in sedimentary systems where infiltration is slower thus, providing information on recharge sources and potential flow paths. Here we report noble gas results from the basal aquifer, springs, and rainwater in Maui to explore the potential for noble gases in characterizing this type of complex fractured hydrologic systems. Most samples display a mass-dependent depletion pattern with respect to surface conditions consistent with previous observations both in the Galapagos Islands and Michigan rainwater. Basal aquifer and rainwater noble gas patterns are similar and suggest direct, fast recharge from precipitation to the basal aquifer. In contrast, multiple springs, representative of perched aquifers, display highly variable noble gas concentrations suggesting recharge from a variety of sources. The distinct noble gas patterns for the basal aquifer and springs suggest that basal and perched aquifers are separate entities. Maui rainwater displays high apparent NGTs, incompatible with surface conditions, pointing either to an origin at high altitudes with the presence of ice or an ice-like source of undetermined origin. Overall, noble gas signatures in Maui reflect the source of recharge rather than the expected altitude/temperature relationship commonly observed in sedimentary systems.

  9. Flexible, Stretchable, and Rechargeable Fiber-Shaped Zinc-Air Battery Based on Cross-Stacked Carbon Nanotube Sheets.

    Science.gov (United States)

    Xu, Yifan; Zhang, Ye; Guo, Ziyang; Ren, Jing; Wang, Yonggang; Peng, Huisheng

    2015-12-14

    The fabrication of flexible, stretchable and rechargeable devices with a high energy density is critical for next-generation electronics. Herein, fiber-shaped Zn-air batteries, are realized for the first time by designing aligned, cross-stacked and porous carbon nanotube sheets simultaneously that behave as a gas diffusion layer, a catalyst layer, and a current collector. The combined remarkable electronic and mechanical properties of the aligned carbon nanotube sheets endow good electrochemical properties. They display excellent discharge and charge performances at a high current density of 2 A g(-1) . They are also flexible and stretchable, which is particularly promising to power portable and wearable electronic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Towards sustainable regions: the spatial distribution of electric vehicles’ recharging stations from a socio-economic perspective

    DEFF Research Database (Denmark)

    Christensen, Linda; Kaplan, Sigal; Jensen, Thomas Christian

    . Firstly, the demand for on-road recharging of EV’s based on the national travel demand patterns is evaluated, while considering the existence of a city-wide slow recharging network. Secondly, the Edison model for the optimal deployment of EV recharging stations is applied. The model evaluates the need...

  11. Towards sustainable regions: the spatial distribution of electric vehicles’ recharging stations from a socio-economic perspective

    DEFF Research Database (Denmark)

    Christensen, Linda; Jensen, Thomas Christian; Kaplan, Sigal

    2012-01-01

    . Firstly, the demand for on-road recharging of EV’s based on the national travel demand patterns is evaluated, while considering the existence of a city-wide slow recharging network. Secondly, the Edison model for the optimal deployment of EV recharging stations is applied. The model evaluates the need...

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

    Science.gov (United States)

    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.

  13. Downstream of downtown: urban wastewater as groundwater recharge

    Science.gov (United States)

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

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

  14. Recharge and flow processes in a till aquitard

    DEFF Research Database (Denmark)

    Schrøder, Thomas Morville; Høgh Jensen, Karsten; Dahl, Mette

    1999-01-01

    Eastern Denmark is primarily covered by clay till. The transformation of the excess rainfall into laterally diverted groundwater flow, drain flow, stream flow, and recharge to the underlying aquifer is governed by complicatedinterrelated processes. Distributed hydrological models provide...... a framework for assessing the individual flow components and forestablishing the overall water balance. Traditionally such models are calibrated against measurements of stream flow, head in the aquiferand perhaps drainage flow. The head in the near surface clay till deposits have generally not been measured...... the shallow wells and one in the valley adjacent to the stream. Precipitation and stream flow gauging along with potential evaporation estimates from a nearby weather station provide the basic data for the overall water balance assessment. The geological composition was determined from geoelectrical surveys...

  15. Layered cathode materials for lithium ion rechargeable batteries

    Science.gov (United States)

    Kang, Sun-Ho [Naperville, IL; Amine, Khalil [Downers Grove, IL

    2007-04-17

    A number of materials with the composition Li.sub.1+xNi.sub..alpha.Mn.sub..beta.Co.sub..gamma.M'.sub..delta.O.sub.2-- zF.sub.z (M'=Mg,Zn,Al,Ga,B,Zr,Ti) for use with rechargeable batteries, wherein x is between about 0 and 0.3, .alpha. is between about 0.2 and 0.6, .beta. is between about 0.2 and 0.6, .gamma. is between about 0 and 0.3, .delta. is between about 0 and 0.15, and z is between about 0 and 0.2. Adding the above metal and fluorine dopants affects capacity, impedance, and stability of the layered oxide structure during electrochemical cycling.

  16. Rechargeable alkaline manganese dioxide cells. A test report

    Science.gov (United States)

    Farrington, Michael D.

    The rechargeable alkaline MnO 2 (RAM) system has now been commercially available for several years. The Canadian Department of National Defence is interested in determining if the low cost RAM system is technically capable of replacing existing cells and batteries now in use. A preliminary study identified sufficient candidate batteries in use within the Department whose performance requirements compared favourably with RAM manufacturers' claims. Further study was warranted. Replacement cost savings could be significant. A study is now in progress that is aimed at determining how well the RAM technology actually performs. This paper presents test results that illustrate how RAM cells compare to primary alkaline cells and nickel/cadmium. The majority of the work is focused on the 'AA' size products from Rayovac and Pure Energy: tests were also conducted on Rayovac 'D' cells.

  17. Rechargeable lithium cells with modified vanadium oxide cathodes

    Science.gov (United States)

    Chung, S. K.; Chmilenko, N. A.; Borovykov, A. Ya; Lee, S. H.

    Modified vanadium oxide has been prepared by melting V 2O 5 with additives of 3-3.5% of sodium orthosilicate at 690°C for 3 h followed by fast cooling to an ambient temperature. Charge-discharge characteristics of this oxide were studied as an active cathode material for lithium secondary batteries. The oxide undergoes irreversible transition to become essentially amorphous after first discharge to cut-off voltage of 2 V vs. Li, and then exhibits excellent rechargeability in the 1.5 to 3.9 V potential range. The coin type 2325 size secondary cells have been manufactured and tested with the modified vanadium oxide cathodes and Li-Al alloy anodes. Preliminary shallow cycling modifies the cells' performance and allows to obtain rating capacity 50 mA h in the voltage diapason of 2.0-3.9 V with draining current 0.5 mA.

  18. Resilient design of recharging station networks for electric transportation vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Kris Villez; Akshya Gupta; Venkat Venkatasubramanian

    2011-08-01

    As societies shift to 'greener' means of transportation using electricity-driven vehicles one critical challenge we face is the creation of a robust and resilient infrastructure of recharging stations. A particular issue here is the optimal location of service stations. In this work, we consider the placement of battery replacing service station in a city network for which the normal traffic flow is known. For such known traffic flow, the service stations are placed such that the expected performance is maximized without changing the traffic flow. This is done for different scenarios in which roads, road junctions and service stations can fail with a given probability. To account for such failure probabilities, the previously developed facility interception model is extended. Results show that service station failures have a minimal impact on the performance following robust placement while road and road junction failures have larger impacts which are not mitigated easily by robust placement.

  19. Conceptualisation of groundwater recharge from the Wairau River, New Zealand

    Science.gov (United States)

    Wilson, Scott; Wöhling, Thomas; Davidson, Peter

    2016-04-01

    The braided Wairau River is the main source of recharge to the Wairau gravel aquifer in Marlborough, New Zealand. Flow measurements indicate a 6 to 15 m3/s loss as the river traverses the Wairau alluvial fan, a distance of 15 km. The hydrological processes regulating this flow loss are not well understood. Theoretically, the relationship between a river and groundwater can be considered as being hydraulically connected (gaining or losing), disconnected, or transitional (Brunner et al. 2011). A disconnected river is distinguished from a hydraulically connected river by a partially saturated zone between the river bed and the aquifer. The aim of this study is to improve our conceptual understanding of how flow losses occur, and to test a new hypothesis that much of the river is hydraulic disconnected from the aquifer. It is practically difficult to make direct observations of the saturation status beneath a river bed. However, indirect observations can be employed to characterize the nature of the river-aquifer exchange, and we have used a variety of data sources (stratigraphy, piezometric surfaces including LiDAR, temperature and radon tracers). Several lines of evidence from these data sources indicate that the dominant recharge reach of the river is hydraulically disconnected, or at least transitional in nature. This simplifies the prediction of transient flow losses, which only requires knowledge of near-surface Kz and wetted river area values. The hydraulic mechanism for a disconnected river condition is the anisotropy of the sandy gravel sequence. The braided river depositional process has formed a finely layered sequence of silt, sand and gravel lenses. This stratification, combined with clast and particle imbrication, has formed a highly anisotropic hydrogeology. Results from aquifer tests analyzed for leakage have typical Kx values of 500 m/d and Kz values of around 0.5 m/d. The large Kx/Kz ratio enables the aquifer to potentially discharge more rapidly in a

  20. Nickel hydroxide positive electrode for alkaline rechargeable battery

    Energy Technology Data Exchange (ETDEWEB)

    Young, Kwo; Wang, Lixin; Mays, William; Reichman, Benjamin; Chao-Ian, Hu; Wong, Diana; Nei, Jean

    2018-02-20

    Certain nickel hydroxide active cathode materials for use in alkaline rechargeable batteries are capable of transferring >1.3 electrons per Ni atom under reversible electrochemical conditions. The specific capacity of the nickel hydroxide active materials is for example .gtoreq.325 mAh/g. The cathode active materials exhibit an additional discharge plateau near 0.8 V vs. a metal hydride (MH) anode. Ni in an oxidation state of less than 2, such as Ni.sup.1+, is able to participate in electrochemical reactions when using the present cathode active materials. It is possible that up to 2.3 electrons, up to 2.5 electrons or more may be transferred per Ni atom under electrochemical conditions.

  1. State of charge estimation in Ni-MH rechargeable batteries

    Energy Technology Data Exchange (ETDEWEB)

    Milocco, R.H. [Grupo Control Automatico y Sistemas (GCAyS), Depto. Electrotecnia, Facultad de Ingenieria, Universidad Nacional del Comahue, Buenos Aires 1400, 8300 Neuquen (Argentina); Castro, B.E. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Universidad Nacional de La Plata, Suc 4, CC16 (1900), La Plata (Argentina)

    2009-10-20

    In this work we estimate the state of charge (SOC) of Ni-MH rechargeable batteries using the Kalman filter based on a simplified electrochemical model. First, we derive the complete electrochemical model of the battery which includes diffusional processes and kinetic reactions in both Ni and MH electrodes. The full model is further reduced in a cascade of two parts, a linear time invariant dynamical sub-model followed by a static nonlinearity. Both parts are identified using the current and potential measured at the terminals of the battery with a simple 1-D minimization procedure. The inverse of the static nonlinearity together with a Kalman filter provide the SOC estimation as a linear estimation problem. Experimental results with commercial batteries are provided to illustrate the estimation procedure and to show the performance. (author)

  2. Spatial Variability of Ground-Water Recharge Estimates in the Glassboro Area, New Jersey

    Science.gov (United States)

    Nolan, B. T.; Baehr, A. L.

    2001-12-01

    The spatial variability of ground-water recharge estimates in the Glassboro area, NJ, was evaluated using geostatistical methods as a preliminarily assessment of aquifer vulnerability. Recharge was estimated using Darcy's law, based on parameters obtained from pedotransfer functions applied to measured soil texture values. The recharge estimates correspond to sediments overlying the Kirkwood-Cohansey aquifer, which comprises highly permeable unconsolidated sands and gravels. Knowing which areas receive greater recharge would indicate areas of greater vulnerability, depending on overlying land use. Recharge varied from -7.3 to 722 in/yr in the study area and the median was 12.1 in/yr. Experimental variograms of untransformed recharge data were erratic and related kriged maps were dominated by extreme values (250-722 in/yr) in the data set. An indicator transform stabilized the variograms. Indicator kriging (IK) reduced the influence of extreme values in the data set and yielded maps showing the probability of exceeding threshold values of recharge in the study area. The probability of exceeding the median recharge rate of 12.1 in/yr was 0.9 in the southern portion of the study area and might represent an area of focused recharge. As a check of model fit, probabilities predicted with IK were compared with the original recharge estimates and found to be strongly related. IK predictions corresponding to quintiles of recharge were used to estimate cumulative distribution functions (cdfs) for specific locations in the study area. The cdfs indicate the probability of exceeding any recharge rate at a particular location, and are shaped differently depending on location in the study area. The IK technique estimates cdfs with a single sampling realization (i.e., without a mean and variance at a given location). Additional variables were analyzed with regression to add a deterministic aspect to the analysis and to improve predictions. These variables included land slope

  3. Response to recharge variation of thin rainwater lenses and their mixing zone with underlying saline groundwater

    Directory of Open Access Journals (Sweden)

    S. Eeman

    2012-10-01

    Full Text Available In coastal zones with saline groundwater, fresh groundwater lenses may form due to infiltration of rain water. The thickness of both the lens and the mixing zone, determines fresh water availability for plant growth. Due to recharge variation, the thickness of the lens and the mixing zone are not constant, which may adversely affect agricultural and natural vegetation if saline water reaches the root zone during the growing season. In this paper, we study the response of thin lenses and their mixing zone to variation of recharge. The recharge is varied using sinusoids with a range of amplitudes and frequencies. We vary lens characteristics by varying the Rayleigh number and Mass flux ratio of saline and fresh water, as these dominantly influence the thickness of thin lenses and their mixing zone. Numerical results show a linear relation between the normalised lens volume and the main lens and recharge characteristics, enabling an empirical approximation of the variation of lens thickness. Increase of the recharge amplitude causes increase and the increase of recharge frequency causes a decrease in the variation of lens thickness. The average lens thickness is not significantly influenced by these variations in recharge, contrary to the mixing zone thickness. The mixing zone thickness is compared to that of a Fickian mixing regime. A simple relation between the travelled distance of the centre of the mixing zone position due to variations in recharge and the mixing zone thickness is shown to be valid for both a sinusoidal recharge variation and actual records of daily recharge data. Starting from a step response function, convolution can be used to determine the effect of variable recharge in time. For a sinusoidal curve, we can determine delay of lens movement compared to the recharge curve as well as the lens amplitude, derived from the convolution integral. Together the proposed equations provide us with a first order approximation of lens

  4. Response to recharge variation of thin rainwater lenses and their mixing zone with underlying saline groundwater

    Science.gov (United States)

    Eeman, S.; van der Zee, S. E. A. T. M.; Leijnse, A.; de Louw, P. G. B.; Maas, C.

    2012-10-01

    In coastal zones with saline groundwater, fresh groundwater lenses may form due to infiltration of rain water. The thickness of both the lens and the mixing zone, determines fresh water availability for plant growth. Due to recharge variation, the thickness of the lens and the mixing zone are not constant, which may adversely affect agricultural and natural vegetation if saline water reaches the root zone during the growing season. In this paper, we study the response of thin lenses and their mixing zone to variation of recharge. The recharge is varied using sinusoids with a range of amplitudes and frequencies. We vary lens characteristics by varying the Rayleigh number and Mass flux ratio of saline and fresh water, as these dominantly influence the thickness of thin lenses and their mixing zone. Numerical results show a linear relation between the normalised lens volume and the main lens and recharge characteristics, enabling an empirical approximation of the variation of lens thickness. Increase of the recharge amplitude causes increase and the increase of recharge frequency causes a decrease in the variation of lens thickness. The average lens thickness is not significantly influenced by these variations in recharge, contrary to the mixing zone thickness. The mixing zone thickness is compared to that of a Fickian mixing regime. A simple relation between the travelled distance of the centre of the mixing zone position due to variations in recharge and the mixing zone thickness is shown to be valid for both a sinusoidal recharge variation and actual records of daily recharge data. Starting from a step response function, convolution can be used to determine the effect of variable recharge in time. For a sinusoidal curve, we can determine delay of lens movement compared to the recharge curve as well as the lens amplitude, derived from the convolution integral. Together the proposed equations provide us with a first order approximation of lens characteristics using

  5. Response to recharge variation of thin lenses and their mixing zone with underlying saline groundwater

    Science.gov (United States)

    Eeman, S.; van der Zee, S. E. A. T. M.; Leijnse, A.; de Louw, P. G. B.; Maas, C.

    2012-01-01

    In coastal zones with saline groundwater, fresh groundwater lenses may form due to infiltration of rain water. The thickness of both the lens and the mixing zone, determines fresh water availability for plant growth. Due to recharge variation, the thickness of the lens and the mixing zone are not constant, which may adversely affect agricultural and natural vegetation if saline water reaches the root zone during the growing season. In this paper, we study the response of thin lenses and their mixing zone to variation of recharge. The recharge is varied using sinusoids with a range of amplitudes and frequencies. We vary lens characteristics by varying the Rayleigh number and Mass flux ratio of saline and fresh water, as these dominantly influence the thickness of thin lenses and their mixing zone. Numerical results show a linear relation between the normalized lens volume and the main lens and recharge characteristics, enabling an analytical approximation of the variation of lens thickness. Increase of the recharge amplitude causes increase, and increase of recharge frequency causes decrease in the variation of lens thickness. The average lens thickness is not significantly influenced by these variations in recharge, contrary to the mixing zone thickness. The mixing zone thickness is compared to that of a Fickian mixing regime. A simple relation between the travelled distance of the center of the mixing zone position due to variations in recharge and the mixing zone thickness is shown to be valid for both a sinusoidal recharge variation and actual records of daily recharge data. Starting from a step response function, convolution can be used to determine the effect of variable recharge in time. For a sinusoidal curve, we can determine delay of lens movement compared to the recharge curve as well as the lens amplitude, derived from the convolution integral. Together the proposed equations provide us with a first order approximation of lens characteristics using basic

  6. An improved void-resistance model for abandoned coal mine gas reservoirs

    OpenAIRE

    Shi, JQ; Rubio, RM; Durucan, S.

    2016-01-01

    Previous studies have shown that the gas pressure behaviour of some abandoned coal mines may be described with the aid of a simple conceptual model, the so called void-resistance model. In this study, an improved void-resistance model has been developed and validated using previously collected data. Two model parameters, i.e. an apparent source/sink pressure and a time constant, which control the gas pressure behaviour during recharge and under certain gas production conditions, are defined. ...

  7. Determination of groundwater recharge mechanism in the deep loessial unsaturated zone by environmental tracers.

    Science.gov (United States)

    Li, Zhi; Chen, Xi; Liu, Wenzhao; Si, Bingcheng

    2017-05-15

    Studying the groundwater recharge mechanism in regions with thick unsaturated zone can greatly improve our understanding of hydrological processes since these regions have complex groundwater processes. This study attempted to discuss the groundwater recharge in a region covered by loess over 130m deep in China's Loess Plateau. The water stable isotope, tritium and chloride in precipitation, groundwater and soil water were determined and used as inputs of mass balance methods. The tracer technique is found to be applicable and effective this region with thick unsaturated zone. The groundwater originates from rapid precipitation infiltration through some fast flow paths. The total recharge is likely to be 107±55mmyr -1 accounting for 19±10% of average annual precipitation, while the recharge from preferential flow accounts for 87±4% of the total recharge. The identified recharge mechanism has important implication to groundwater management and recharge modeling for regions covered by thick loess. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Spatial variability of groundwater recharge and its effect on shallow groundwater quality in southern New Jersey

    Science.gov (United States)

    Nolan, Bernard T.; Baehr, Arthur L.; Kauffman, Leon J.

    2003-01-01

    Point estimates of groundwater recharge at 48 sediment-coring locations vary substantially (−18.5–1840 cm yr−1) in a 930-km2 area of southern New Jersey. Darcian estimates of steady, long-term recharge made at depth in the unsaturated zone were estimated using pedotransfer functions of soil texture and interpolated (mapped) with nonparametric methods to assess aquifer vulnerability in the area. The probability of exceeding the median recharge (29.1 cm yr−1) is low in the southwestern and northeastern portions of the study area and high in the eastern and southeastern portions. Estimated recharge is inversely related to measured percentage clay and positively related to the percentage of well-drained soils near wells. Spatial patterns of recharge estimates, exceedance probabilities, and clay content indicate that sediment texture controls recharge in the study area. Relations with land elevation and a topographic wetness index were statistically insignificant. Nitrate concentration and atrazine (6-chloro-N 2-ethyl-N 4-isopropyl-1,3,5-triazine-2,4-diamine) percentage detection in samples of shallow groundwater (typically 29.1 cm yr−1) in agricultural and urban areas. Differences between high and low recharge sites in these areas are highly significant for NO3 concentration, but not for atrazine concentration.

  9. The Impact of a Check Dam on Groundwater Recharge and Sedimentation in an Ephemeral Stream

    Directory of Open Access Journals (Sweden)

    Hakan Djuma

    2017-10-01

    Full Text Available Despite the widespread presence of groundwater recharge check dams, there are few studies that quantify their functionality. The objectives of this study are (i to assess groundwater recharge in an ephemeral river with and without a check dam and (ii to assess sediment build-up in the check-dam reservoir. Field campaigns were carried out to measure water flow, water depth, and check-dam topography to establish water volume, evaporation, outflow, and recharge relations, as well as sediment build-up. To quantify the groundwater recharge, a water-balance approach was applied at two locations: at the check dam reservoir area and at an 11 km long natural stretch of the river upstream. Prediction intervals were computed to assess the uncertainties of the results. During the four years of operation, the check dam (storage capacity of 25,000 m3 recharged the aquifer with an average of 3.1 million m3 of the 10.4 million m3 year−1 of streamflow (30%. The lower and upper uncertainty limits of the check dam recharge were 0.1 and 9.6 million m3 year−1, respectively. Recharge from the upstream stretch was 1.5 million m3 year−1. These results indicate that check dams are valuable structures for increasing groundwater resources in semi-arid regions.

  10. Artificial groundwater recharge zones mapping using remote sensing and GIS: a case study in Indian Punjab.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2011-01-01

    Accurate estimates of groundwater recharge are essential for effective management of groundwater, especially when supplies are limited such as in many arid and semiarid areas. In the Hebei Plain, China, water shortage is increasingly restricting socioeconomic development, especially for agriculture, which heavily relies on groundwater. Human activities have greatly changed groundwater recharge there during the past several decades. To obtain better estimates of recharge in the plain, five representative sites were selected to investigate the effects of irrigation and water table depth on groundwater recharge. At each site, a one-dimensional unsaturated flow model (Hydrus-1D) was calibrated using field data of climate, soil moisture, and groundwater levels. A sensitivity analysis of evapotranspirative fluxes and various soil hydraulic parameters confirmed that fine-textured surface soils generally generate less recharge. Model calculations showed that recharge on average is about 175 mm/year in the piedmont plain to the west, and 133 mm/year in both the central alluvial and lacustrine plains and the coastal plain to the east. Temporal and spatial variations in the recharge processes were significant in response to rainfall and irrigation. Peak time-lags between infiltration (rainfall plus irrigation) and recharge were 18 to 35 days in the piedmont plain and 3 to 5 days in the central alluvial and lacustrine plains, but only 1 or 2 days in the coastal plain. This implies that different time-lags corresponding to different water table depths must be considered when estimating or modeling groundwater recharge. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

  12. Comparative study of climate-change scenarios on groundwater recharge, southwestern Mississippi and southeastern Louisiana, USA

    Science.gov (United States)

    Beigi, Ehsan; Tsai, Frank T.-C.

    2015-02-01

    A geographic information system (GIS)-based water-budget framework has been developed to study the climate-change impact on regional groundwater recharge, and it was applied to the Southern Hills aquifer system of southwestern Mississippi and southeastern Louisiana, USA. The framework links historical climate variables and future emission scenarios of climate models to a hydrologic model, HELP3, to quantify spatiotemporal potential recharge variations from 1950 to 2099. The framework includes parallel programming to divide a large amount of HELP3 simulations among multiple cores of a supercomputer, to expedite computation. The results show that a wide range of projected potential recharge for the Southern Hills aquifer system resulted from the divergent projections of precipitation, temperature and solar radiation using three scenarios (B1, A2 and A1FI) of the National Center for Atmospheric Research's Parallel Climate Model 1 (PCM) and the National Oceanic and Atmospheric Administration Geophysical Fluid Dynamics Lab's (GFDL) model. The PCM model projects recharge change ranging from -33.7 to +19.1 % for the 21st century. The GFDL model projects less recharge than the PCM, with recharge change ranging from -58.1 to +7.1 %. Potential recharge is likely to increase in 2010-2039, but likely to decrease in 2070-2099. Projected recharge is more sensitive to the changes in the projected precipitation than the projected solar radiation and temperature. Uncertainty analysis confirms that the uncertainty in projected precipitation yields more changes in the potential recharge than in the projected temperature for the study area.

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

    Science.gov (United States)

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

    2012-01-01

    Climate variability and change impact groundwater resources by altering recharge rates. In semi-arid Basin and Range systems, this impact is likely to be most pronounced in mountain system recharge (MSR), a process which constitutes a significant component of recharge in these basins. Despite its importance, the physical processes that control MSR have not been fully investigated because of limited observations and the complexity of recharge processes in mountainous catchments. As a result, empirical equations, that provide a basin-wide estimate of mean annual recharge using mean annual precipitation, are often used to estimate MSR. Here North American Regional Reanalysis data are used to develop seasonal recharge estimates using ratios of seasonal (winter vs. summer) precipitation to seasonal actual or potential evapotranspiration. These seasonal recharge estimates compared favorably to seasonal MSR estimates using the fraction of winter vs. summer recharge determined from isotopic data in the Upper San Pedro River Basin, Arizona. Development of hydrologically based seasonal ratios enhanced seasonal recharge predictions and notably allows evaluation of MSR response to changes in seasonal precipitation and temperature because of climate variability and change using Global Climate Model (GCM) climate projections. Results show that prospective variability in MSR depends on GCM precipitation predictions and on higher temperature. Lower seasonal MSR rates projected for 2050-2099 are associated with decreases in summer precipitation and increases in winter temperature. Uncertainty in seasonal MSR predictions arises from the potential evapotranspiration estimation method, the GCM downscaling technique and the exclusion of snowmelt processes. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

  14. Ground-Water Recharge in the Arid and Semiarid Southwestern United States - Climatic and Geologic Framework

    Science.gov (United States)

    Stonestrom, David A.; Harrill, James R.

    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 Ni?o 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 Ni?o 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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  18. The Electric Fleet Size and Mix Vehicle Routing Problem with Time Windows and Recharging Stations

    DEFF Research Database (Denmark)

    Hiermann, Gerhard; Puchinger, Jakob; Røpke, Stefan

    2016-01-01

    detours to recharging stations necessary, thus requiring efficient tour planning mechanisms in order to sustain the competitiveness of electric vehicles compared to conventional vehicles. We introduce the Electric Fleet Size and Mix Vehicle Routing Problem with Time Windows and Recharging Stations (E......-FSMFTW) to model decisions to be made with regards to fleet composition and the actual vehicle routes including the choice of recharging times and locations. The available vehicle types differ in their transport capacity, battery size and acquisition cost. Furthermore, we consider time windows at customer...

  19. Effects of groundwater recharge rates and nutrient supply on metabolic pathways for coal bed methane generation in the Powder River Basin

    Science.gov (United States)

    Bates, B. L.; McIntosh, J. C.

    2008-12-01

    The Powder River Basin (PRB), located in northeastern Wyoming (USA), is a principle producer of coal bed methane world-wide. The basin contains an extensive natural gas well network, which combined with past studies, facilitates a unique opportunity to study the coupling of hydrology and microbial methane generation. Microbes generate methane via two metabolic pathways, acetate fermentation and carbon dioxide reduction, which can be distinguished using C and H isotopes of CO2, CH4, and H2O, and DNA studies. The relative importance of these pathways is primarily dependent on the bioavailability of organic matter, presence of nutrients, salinity, and microbial community structure. Previous studies by Flores et al. (2008) observed the dominance of acetoclastic methanogenesis in select areas near the basin margins where the coal zones were burned (clinker deposits). Methane generated via CO2 reduction is dominant at depth throughout the basin. We hypothesize that the spatial and depth distribution of CO2 versus acetate -utilizing methanogens in the PRB is related to groundwater recharge rates, residence times, proximity to clinker deposits, and nutrient supply. To test this hypothesis, we collected co-produced groundwaters and natural gas from 32 wells, along two transects across the basin that were parallel to regional hydrologic gradients. Four shallow groundwater samples were also collected from a surface coal mine. Oxygen and hydrogen isotopes, tritium, and carbon-14 were used to estimate apparent groundwater ages and recharge rates. Variations in ion concentrations (e.g. Cl, SO4, NO3, NO2, NH4, PO4, SO4, acetate) were coupled to age tracers to determine the effects of recharge rates and flowpaths on nutrient transport and cycling, which may in turn affect metabolic pathways for methane generation in organic-rich aquifers.

  20. Morphology-Controllable Synthesis of Zn-Co-Mixed Sulfide Nanostructures on Carbon Fiber Paper Toward Efficient Rechargeable Zinc-Air Batteries and Water Electrolysis.

    Science.gov (United States)

    Wu, Xiaoyu; Han, Xiaopeng; Ma, Xiaoya; Zhang, Wei; Deng, Yida; Zhong, Cheng; Hu, Wenbin

    2017-04-12

    It remains an ongoing challenge to develop cheap, highly active, and stable electrocatalysts to promote the sluggish electrocatalytic oxygen evolution, oxygen reduction, and hydrogen evolution reactions for rechargeable metal-air batteries and water-splitting systems. In this work, we report the morphology-controllable synthesis of zinc cobalt mixed sulfide (Zn-Co-S) nanoarchitectures, including nanosheets, nanoplates, and nanoneedles, grown on conductive carbon fiber paper (CFP) and the micronanostructure dependent electrochemical efficacy for catalyzing hydrogen and oxygen in zinc-air batteries and water electrolysis. The formation of different Zn-Co-S morphologies was attributed to the synergistic effect of decomposed urea products and the corrosion of NH 4 F. Among synthesized Zn-Co-S nanostructures, the nanoneedle arrays supported on CFP exhibit superior trifunctional activity for oxygen reduction, oxygen evolution, and hydrogen evolution reactions than its nanosheet and nanoplate counterparts through half reaction testing. It also exhibited better catalytic durability than Pt/C and RuO 2 . Furthermore, the Zn-Co-S nanoneedle/CFP electrode enables rechargeable Zn-air batteries with low overpotential (0.85 V), high efficiency (58.1%), and long cycling lifetimes (200 cycles) at 10 mA cm -2 as well as considerable performance for water splitting. The superior performance is contributed to the integrated nanoneedle/CFP nanostructure, which not only provides enhanced electrochemical active area, but also facilitates ion and gas transfer between the catalyst surface and electrolyte, thus maintaining an effective solid-liquid-gas interface necessary for electrocatalysis. These results indicate that the Zn-Co-S nanoneedle/CFP system is a low cost, highly active, and durable electrode for highly efficient rechargeable zinc-air batteries and water electrolysis in alkaline solution.

  1. Recharge Net Metering to Incentivize Sustainable Groundwater Management

    Science.gov (United States)

    Fisher, A. T.; Coburn, C.; Kiparsky, M.; Lockwood, B. S.; Bannister, M.; Camara, K.; Lozano, S.

    2016-12-01

    Stormwater runoff has often been viewed as a nuisance rather than a resource, but with passage of the Sustainable Groundwater Management Act (2014), many basins in California are taking a fresh look at options to enhance groundwater supplies with excess winter flows. In some basins, stormwater can be used for managed aquifer recharge (MAR), routing surface water to enhance groundwater resources. As with many public infrastructure programs, financing for stormwater-MAR projects can be a challenge, and there is a need for incentives that will engage stakeholders and offset operation and maintenance costs. The Pajaro Valley Water Management Agency (PVWMA), in central costal California, recently launched California's first Recharge Net Metering (ReNeM) program. MAR projects that are part of the ReNeM program are intended to generate ≥100 ac-ft/yr of infiltration benefit during a normal water year. A team of university and Resource Conservation District partners will collaborate to identify and assess potential project sites, screening for hydrologic conditions, expected runoff, ease and cost of project construction, and ability to measure benefits to water supply and quality. The team will also collect data and samples to measure the performance of each operating project. Groundwater wells within the PVWMA's service area are metered, and agency customers pay an augmentation fee for each unit of groundwater pumped. ReNeM projects will earn rebates of augmentation fees based on the amount of water infiltrated, with rebates calculated using a formula that accounts for uncertainties in the fate of infiltrated water, and inefficiencies in recovery. The pilot ReNeM program seeks to contribute 1000 ac-ft/yr of infiltration benefit by the end of the initial five-year operating period. ReNeM offers incentives that are distinct from those derived from traditional groundwater banking, and thus offers the potential for an innovative addition to the portfolio of options for

  2. Removal of organic micropollutants in an artificial recharge system

    Science.gov (United States)

    Valhondo, C.; Nödler, K.; Köck-Schulmeyer, M.; Hernandez, M.; Licha, T.; Ayora, C.; Carrera, J.

    2012-04-01

    Emerging contaminants including pharmaceutically active compounds (PhACs), personal care products (PCPs) and pesticides are increasingly being identified in the environment. Emerging pollutants and their transformation products show low concentration in the environment (ng/L), but the effects of the mixtures and lifelong exposure to humans are currently unknown. Many of these contaminants are removed under aerobic conditions in water treatment plants. However, several pharmaceuticals and metabolites present in wastewater are not eliminated by conventional treatment processes. Several lab studies, however, show that the behaviour of many of these micropollutants is affected by the dominant redox conditions. However, data from field experiments are limited and sometimes contradictory. Artificial recharge is a widespread technology to increase the groundwater resources. In this study we propose a design to enhance the natural remediation potential of the aquifer with the installation of a reactive layer at the bottom of the infiltration pond. This layer is a mixture of compost, aquifer material, clay and iron oxide. This layer is intended to provide an extra amount of DOC to the recharge water and to promote biodegradation by means of the development of different redox zones along the travel path through the unsaturated zone and within the aquifer. Moreover, compost, clay and iron oxide of the layer are assumed to increase sorption surfaces for neutral, cationic and anionic compounds, respectively. The infiltration system is sited in Sant Vicenç dels Horts (Barcelona, Spain). It consists of a decantation pond, receiving raw water from the Llobregat River (highly affected from treatment plant effluents), and an infiltration pond (5600 m2). The infiltration rate is around 1 m3/m2/day. The system is equipped with a network of piezometers, suction cups and tensiometers. Infiltration periods have been performed before and after the installation of the reactive layer

  3. Electrochemical Techniques for Intercalation Electrode Materials in Rechargeable Batteries.

    Science.gov (United States)

    Zhu, Yujie; Gao, Tao; Fan, Xiulin; Han, Fudong; Wang, Chunsheng

    2017-04-18

    Understanding of the thermodynamic and kinetic properties of electrode materials is of great importance to develop new materials for high performance rechargeable batteries. Compared with computational understanding of physical and chemical properties of electrode materials, experimental methods provide direct and convenient evaluation of these properties. Often, the information gained from experimental work can not only offer feedback for the computational methods but also provide useful insights for improving the performance of materials. However, accurate experimental quantification of some properties can still be challenging. Among them, chemical diffusion coefficient is one representative example. It is one of the most crucial parameters determining the kinetics of intercalation compounds, which are by far the dominant electrode type used in rechargeable batteries. Therefore, it is of significance to quantitatively evaluate this parameter. For this purpose, various electrochemical techniques have been invented, for example, galvanostatic intermittent titration technique (GITT), potentiostatic intermittent titration technique (PITT), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). One salient advantage of these electrochemical techniques over other characterization techniques is that some implicit thermodynamic and kinetic quantities can be linked with the readily measurable electrical signals, current, and voltage, with very high precision. Nevertheless, proper application of these techniques requires not just an understanding of the structure and chemistry of the studied materials but sufficient knowledge of the physical model for ion transport within solid host materials and the analysis method to solve for chemical diffusion coefficient. Our group has been focusing on using various electrochemical techniques to investigate battery materials, as well as developing models for studying some emerging materials. In this Account, the

  4. Arsenic mobilization and attenuation by mineral–water interactions: implications for managed aquifer recharge

    Science.gov (United States)

    Managed aquifer recharge (MAR) has a potential for addressing deficits in water supplies worldwide. It is also widely used for preventing saltwater intrusion, maintaining the groundwater table, and augmenting ecological stream flows among many beneficial environmental application...

  5. Time‐lapse gravity data for monitoring and modeling artificial recharge through a thick unsaturated zone

    National Research Council Canada - National Science Library

    Kennedy, Jeffrey; Ferré, Ty P. A; Creutzfeldt, Benjamin

    2016-01-01

    .... We demonstrate that for an artificial recharge facility with a deep groundwater table, gravity data are more sensitive to movement of water through the unsaturated zone than are groundwater levels...

  6. Uncertainty and urban water recharge for managing groundwater availability using decision support.

    Science.gov (United States)

    Passarello, M C; Pierce, S A; Sharp, J M

    2014-01-01

    Quantifying groundwater availability depends upon sound methods and the use of integrated models. To determine availability or sustainable yield, the influence of scientific uncertainty from key sources, such as anthropogenic recharge, must be considered. This study evaluates uncertainty in recharge interpretations on the modeled available water balance for an urban case in Texas, USA. Analyses are completed using the Groundwater Decision Support System, which is a research code-base for an integrated modeling. The case study develops spatially and temporally resolved recharge interpretations based on NEXRAD precipitation and detailed land use data. Results demonstrate the implications of scientific uncertainty as it influences recommendations for policy and urban water management decisions that are based on modeled outputs. Geospatial methods account for spatial and temporal components and can be replicated for other systems. These methods are also useful for resolving uncertainty in relation to the influence of urbanization on recharge through land use change.

  7. Rechargeable battery-triggered electrochemiluminescence detection on microfluidic origami immunodevice based on two electrodes.

    Science.gov (United States)

    Wang, Shaowei; Dai, Weijian; Ge, Lei; Yan, Mei; Yu, Jinghua; Song, Xianrang; Ge, Shenguang; Huang, Jiadong

    2012-10-14

    A low-cost, portable rechargeable battery was firstly used to fabricate a battery-triggered, screen-printed two-electrode electrochemiluminescent immunoassay on a 3D microfluidic origami electronic device.

  8. Recharge Data Package for the 2005 Integrated Disposal Facility Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Fayer, Michael J.; Szecsody, Jim E.

    2004-06-30

    Pacific Northwest National Laboratory assisted CH2M Hill Hanford Group, Inc., (CHG) by providing estimates of recharge rates for current conditions and long-term scenarios involving disposal in the Integrated Disposal Facility (IDF). The IDF will be located in the 200 East Area at the Hanford Site and will receive several types of waste including immobilized low-activity waste. The recharge estimates for each scenario were derived from lysimeter and tracer data collected by the IDF PA Project and from modeling studies conducted for the project. Recharge estimates were provided for three specific site features (the surface barrier; possible barrier side slopes; and the surrounding soil) and four specific time periods (pre-Hanford; Hanford operations; surface barrier design life; post-barrier design life). CHG plans to conduct a performance assessment of the latest IDF design and call it the IDF 2005 PA; this recharge data package supports the upcoming IDF 2005 PA.

  9. Estimated mean annual natural ground-water recharge in the conterminous United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This 1-kilometer resolution raster (grid) dataset is an index of mean annual natural ground-water recharge. The dataset was created by multiplying a grid of...

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

    Science.gov (United States)

    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

  11. Estimation of soil moisture and groundwater recharge using the TOPOG_IRM Model

    National Research Council Canada - National Science Library

    Zhang, L; Dawes, W. R; Hatton, T. J; Reece, P. H; Beale, G. T. H; Packer, I

    1999-01-01

    A distributed parameter ecohydrological model (TOPOG_IRM) was applied to a 1.6 km 2 pastoral catchment in southeast Australia for estimating soil moisture and groundwater recharge, for a period of 1992–1994...

  12. Novel Anodes for Rapid Recharge High Energy Density Lithium-ion Batteries Project

    Data.gov (United States)

    National Aeronautics and Space Administration — TIAX proposes to develop as a novel negative electrode active material for rechargeable lithium-ion batteries. This material will fill the gap between the...

  13. Assessment of groundwater recharge potential zone using GIS approach in Purworejo regency, Central Java province, Indonesia

    Science.gov (United States)

    Aryanto, Daniel Eko; Hardiman, Gagoek

    2018-02-01

    Floods and droughts in Purworejo regency are an indication of problems in groundwater management. The current development progress has led to land conversion which has an impact on the problem of water infiltration in Purworejo regency. This study aims to determine the distribution of groundwater recharge potential zones by using geographic information system as the basis for ground water management. The groundwater recharge potential zone is obtained by overlaying all the thematic maps that affect the groundwater infiltration. Each thematic map is weighted according to its effect on groundwater infiltration such as land-use - 25%, rainfall - 20%, litology - 20%, soil - 15%, slope - 10%, lineament - 5%, and river density - 5% to find groundwater recharge potential zones. The groundwater recharge potential zones thus obtained were divided into five categories, viz., very high, high, medium, low and very low zones. The results of this study may be useful for better groundwater planning and management.

  14. Estimation of Groundwater Recharge Using Tracers and Numerical Modeling in the North China Plain

    Directory of Open Access Journals (Sweden)

    Qinghua Wu

    2016-08-01

    Full Text Available Water resource shortage has been a serious problem since the 1980s in the North China Plain (NCP, resulting in plenty of environmental problems. Estimating the groundwater recharge rate accurately is vital for managing groundwater effectively. This study applied several methods, including chloride mass-balance, tracers (bromide and tritium and numerical modeling (Hydrus-1D, to estimate groundwater recharge at three representative sites of the NCP: Zhengding (ZD, Luancheng (LC and Hengshui (HS. The chloride concentration of the soil profile in the ZD site showed that the mean recharge was 3.84 mm/year with the residence time of 105 years for soil water transferring through the vadose area of 45.0 m in depth in the preferential flow model mainly. Considering the influence of preferential flow on the soil water movement in the field scale, the traditional methods (e.g., peak method of bromide and tritium tracers based on piston flow described in the literature could be unsuitable to estimate groundwater recharge in the LC and HS sites, especially in areas with low recharge rates. Therefore, multi-region and mass balance methods were applied in this study. The results of this investigation showed that the mean values of recharge were 124.3 and 18.0 mm/year in the LC and HS sites, respectively, in 2010. Owing to complexity and uncertainty on the surface resulting from the measuring of evapotranspiration, the upper boundary of 1.4 m (under the ground where most of the plant roots did not reach was chosen for the numerical modeling of Hydrus-1D, and the result showed that the mean recharge was 225 mm/year from 2003 to 2007, consistent with the result of tracers in the previous literature. The result also showed that the positive relation of groundwater recharge and the sum of irrigation and rainfall was presented in the spatial and temporal scale. Additionally, human activities promoted the recharge rate, and recharge rates increased with greater

  15. Incorporation of Satellite Data and Uncertainty in a Nationwide Groundwater Recharge Model in New Zealand

    Directory of Open Access Journals (Sweden)

    Rogier Westerhoff

    2018-01-01

    Full Text Available A nationwide model of groundwater recharge for New Zealand (NGRM, as described in this paper, demonstrated the benefits of satellite data and global models to improve the spatial definition of recharge and the estimation of recharge uncertainty. NGRM was inspired by the global-scale WaterGAP model but with the key development of rainfall recharge calculation on scales relevant to national- and catchment-scale studies (i.e., a 1 km × 1 km cell size and a monthly timestep in the period 2000–2014 provided by satellite data (i.e., MODIS-derived evapotranspiration, AET and vegetation in combination with national datasets of rainfall, elevation, soil and geology. The resulting nationwide model calculates groundwater recharge estimates, including their uncertainty, consistent across the country, which makes the model unique compared to all other New Zealand estimates targeted towards groundwater recharge. At the national scale, NGRM estimated an average recharge of 2500 m 3 /s, or 298 mm/year, with a model uncertainty of 17%. Those results were similar to the WaterGAP model, but the improved input data resulted in better spatial characteristics of recharge estimates. Multiple uncertainty analyses led to these main conclusions: the NGRM model could give valuable initial estimates in data-sparse areas, since it compared well to most ground-observed lysimeter data and local recharge models; and the nationwide input data of rainfall and geology caused the largest uncertainty in the model equation, which revealed that the satellite data could improve spatial characteristics without significantly increasing the uncertainty. Clearly the increasing volume and availability of large-scale satellite data is creating more opportunities for the application of national-scale models at the catchment, and smaller, scales. This should result in improved utility of these models including provision of initial estimates in data-sparse areas. Topics for future

  16. Recharge and Aquifer Response: Manukan Island’s Aquifer, Sabah, Malaysia

    Directory of Open Access Journals (Sweden)

    Sarva Mangala Praveena

    2010-01-01

    Full Text Available Manukan Island is a small island located in North-West of Sabah, Malaysia was used as a case study area for numerical modeling of an aquifer response to recharge and pumping rates. The results in this study present the variations of recharge into the aquifer under the prediction simulations. The recharge rate increases the water level as indicated by hydraulic heads. This shows that it can alter groundwater of Manukan Island which has been suffering from an overexploration in its unconfined the aquifer. The increase in recharge rate (from 600 mm/year to 750 mm/year increases the water level indicated by hydraulic heads. A reduction in pumping rate (from 0.072 m3/day to 0.058 m3/day not only increases the amount of water levels in aquifer but also reduces the supply hence a deficit in supply. The increase in hydraulic heads depends on the percentage reduction of pumping and recharges rates. The well water has 1978.3 mg/L chloride with current pumping (0.072 m3/day and recharge rates (600 mm/year. However, with an increased of recharge rate and current pumping rate it has decreased about 1.13%. In addition, reduction in pumping rate made the chloride concentration decreased about 2.8%. In general, a reduction in pumping with an increase in recharge rate leads to a decreased in chloride concentrations within the vicinity of cone of depression. Next, to further develop the numerical model, the model should focus on climate change variables such as consequences of climate change are increase in air temperature, increase in sea surface temperature, and more extreme weather conditions. These parameters are considered critical parameters for climate change impact modeling in aquifers. The behavior of the aquifer and its sustainable pumping rate can be done by applying a computer modeling component.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  19. Groundwater recharge in a multi-aquifer system in Iloilo, Philippines

    Science.gov (United States)

    Geronia, M. C. M.

    2016-12-01

    For rapidly urbanizing areas, groundwater utilization has been subject to contentions concerning its allocation and supply. The Philippines, an industrializing and developing country, primarily taps surface water for supply but has been extracting groundwater in increasing amounts in recent years. Despite abundant rainfall, the recharge and rainfall proportion for the Philippines just ranges from 7 to 10 percent, causing low recharge rates. Iloilo, a developing metropolis in central Philippines, has started to run into groundwater supply shortages. The city has already been tapping 93% of its supply from deep aquifers for years but low and unpredictable recharge and lack of groundwater studies increase uncertainties to the city's water situation. This study analyzed the relationship among the city's volcanic and clastic multi-aquifer systems and groundwater recharge during the wet season. Constant-rate pumping tests were performed and time-drawdown data were collected on wells at different depths scattered across the city. Hydrographs were computed and analyzed for the basin to determine rainfall-recharge relationship for the aquifer system and were compared to available historical data. Results showed shallow aquifers with depths less than 20 meters, as expected, were still subject to recharge especially during wet season. However, urbanization and increased abstraction from unregulated wells further worsened by an El Niño-induced 6-month drought had started to dry up the shallow perched aquifers, resulting to a net decrease in available supply. Aquifer recharge at depths between 50 to 70 meters has decreased substantially, potentially threatening the city's water supply for the long term. Nonetheless, characterizing and quantifying the relationship of the Iloilo aquifer system and recharge have given a much better picture of the situation that will benefit the city in water resource planning and allocation in light of future hydrological and climate risks.

  20. Water reclamation for aquifer recharge at the eight case study sites: a cross case analysis

    CSIR Research Space (South Africa)

    Le Corre, K

    2012-06-01

    Full Text Available Reclamation Technologies for Safe Managed Aquifer Recharge Water reclamation for aquifer recharge at the eight case study sites: a cross case analysis Le Corre, Kristell, Aharoni, Avi, Cauwenberghs, Johan, Chavez, Alma, Cikurel, Haim,Ayuso Gabella..., Tredoux, Gideon, Wintgens, Thomas, Cheng Xuzhou, Yu, Liang and Zhao, Xuan Abstract: Water scarcity combined with the quality deterioration of freshwater due to the rapid augmentation of population and industrial development is a major concern...

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

    Science.gov (United States)

    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.

  2. Sensitivity of groundwater recharge using climatic analogues and HYDRUS-1D

    OpenAIRE

    B. Leterme; D. Mallants; Jacques, D.

    2012-01-01

    The sensitivity of groundwater recharge to different climate conditions was simulated using the approach of climatic analogue stations, i.e. stations presently experiencing climatic conditions corresponding to a possible future climate state. The study was conducted in the context of a safety assessment of a future near-surface disposal facility for low and intermediate level short-lived radioactive waste in Belgium; this includes estimation of groundwater recharge for the next millennia. Gro...

  3. Constraining recharge and groundwater models with HydEOmex soil moisture observations

    OpenAIRE

    Jackson, Christopher; Bianchi, Marco

    2016-01-01

    Estimation of groundwater recharge has underpinned a wide variety of groundwater resource and quality assessments within the UK at a range of scales. For example, there are many studies that have quantified time‑varying recharge rates in order to model the transport of diffuse and point-source pollutants from the land surface, through groundwater systems to receptors such as rivers and abstraction boreholes (e.g. Stuart et al., 2006; Wilby et al., 2006; Jackson et al., 2007; Cuthbert et al., ...

  4. Estimation of natural direct groundwater recharge in southwest Ghana using water balance simulations

    OpenAIRE

    Darko, Philip K.

    2002-01-01

    The Sacramento soil moisture-accounting model has been used to simulate the discharges of a major catchment (Pra river basin) in southern Ghana. Through the simulation it was possible to assess the temporal variability of evapotranspiratio, base flow proportions and groundwater in storage, as well as the average groundwater recharge to the weathered aquifers. Groundwater recharge was estimated by considering the measured discharge of groundwater across the boundary of the basin over periods o...

  5. Estimation of Shallow Groundwater Recharge Using a Gis-Based Distributed Water Balance Model

    OpenAIRE

    Graf Renata; Przybyłek Jan

    2014-01-01

    In the paper we present the results of shallow groundwater recharge estimation using the WetSpass GISbased distributed water balance model. By taking into account WetSpass, which stands for Water an Energy Transfer between Soil, Plants and Atmosphere under quasi-Steady State, for average conditions during the period 1961–2000, we assessed the spatial conditions of the groundwater infiltration recharge process of shallow circulation systems in the Poznan Plateau area (the Great Pol...

  6. Fluoride Release and Recharge from Different Materials Used as Fissure Sealants

    OpenAIRE

    Bayrak, Sule; Tunc, Emine Sen; AKSOY, Abdurrahman; Ertas, Ertan; Guvenc, Dilek; Ozer, Sezin

    2010-01-01

    Objectives: Fluoride release/recharge properties of fissure sealants are important for their long-term inhibition of caries. This study was conducted to examine the relationship between fluoride release and recharge of pit-and-fissure sealants. Methods: Specimens were prepared from 5 different sealant materials: Fissurit F, a conventional resin; Fuji VII, a glass-ionomer cement (GIC); Fuji II LC, a resin-modified GIC; Ionosit, a polyacid-modified composite resin (PMRC); and Aelite Flo, a flow...

  7. 3D Ordered Mesoporous Bifunctional Oxygen Catalyst for Electrically Rechargeable Zinc-Air Batteries.

    Science.gov (United States)

    Park, Moon Gyu; Lee, Dong Un; Seo, Min Ho; Cano, Zachary Paul; Chen, Zhongwei

    2016-05-01

    To enhance energy efficiency and durability, a highly active and durable 3D ordered mesoporous cobalt oxide framework has been developed for rechargeable zinc-air batteries. The bifunctional air electrode consisting of 3DOM Co3 O4 having high active surface area and robust structure, results in superior charge and discharge battery voltages, and durable performance for electrically rechargeable zinc-air batteries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Eastern and Central Pacific ENSO and their relationships to the recharge/discharge oscillator paradigm

    OpenAIRE

    Singh, A.; Delcroix, Thierry

    2013-01-01

    One of the leading theories to explain the oscillatory nature of the El Nino Southern Oscillation is the recharge-discharge oscillator paradigm, which roots on warm waters exchanged between the equatorial and off-equatorial regions. This study tests the relevance of this theory to account for the Eastern and recently mediated Central Pacific El Nino events. The recharge-discharge of the equatorial Pacific, measured here as changes in Warm (> 20 degrees C) Water Volume (WWV), is analysed using...

  9. Trends and variability of East African rainfall and its relationship to the Mascarene High pressure system

    Science.gov (United States)

    Seregina, Larisa; Pinto, Joaquim G.; Fink, Andreas H.; Ermert, Volker

    2016-04-01

    In the recent decades, East Africa needs to deal with strong fluctuations in seasonal rainfall including precipitation extremes. In context of climate change, such extremes can become more frequent in the future. However, regional climate projections are uncertain about the future development of seasonal precipitation in the region. Rainfall regimes over East Africa are influenced by multiple factors, including two monsoon systems, several convergence zones and the Rift Valley lakes. In addition, local conditions, like topography, modulate the large-scale rainfall pattern. East African rainfall variability is also influenced by various teleconnections like the Indian Ocean Zonal Mode and El Niño Southern Oscillation. The study of past climate variability in East Africa requires sufficient observational data coverage in the region. As East Africa does not have a dense observational network of meteorological stations, satellite rainfall observations gain on importance in studies on climate variability in the region. The specific aim of the present study is the analysis of historic data from weather stations in East Africa (Kenya, Tanzania, Ruanda and Uganda), the use of gridded satellite products, and three-dimensional atmospheric reanalysis (e.g., ERA-Interim) to quantify climate variability in the recent past and to understand its causes. Climate variability and trends, including changes in extreme events, are evaluated using ETCCDI climate change and standardized precipitation indices. These climate indices are determined in order to investigate the variability of rainfall and its trends with the focus on recent decades. For seasonal trend analysis, an independent and non-calendaric rainfall onset criterion is introduced. In the follow-up, statistical and dynamical analyses are conducted to quantify the local impact of Mascarene High as a part of the Subtropical High Pressure Ridge on East African seasonal rainfall. Possible connections to pertinent large-scale modes of climate variability (Indian Ocean Zonal Mode and El Niño Southern Oscillation) are expected.

  10. Joint Power Charging and Routing in Wireless Rechargeable Sensor Networks.

    Science.gov (United States)

    Jia, Jie; Chen, Jian; Deng, Yansha; Wang, Xingwei; Aghvami, Abdol-Hamid

    2017-10-09

    The development of wireless power transfer (WPT) technology has inspired the transition from traditional battery-based wireless sensor networks (WSNs) towards wireless rechargeable sensor networks (WRSNs). While extensive efforts have been made to improve charging efficiency, little has been done for routing optimization. In this work, we present a joint optimization model to maximize both charging efficiency and routing structure. By analyzing the structure of the optimization model, we first decompose the problem and propose a heuristic algorithm to find the optimal charging efficiency for the predefined routing tree. Furthermore, by coding the many-to-one communication topology as an individual, we further propose to apply a genetic algorithm (GA) for the joint optimization of both routing and charging. The genetic operations, including tree-based recombination and mutation, are proposed to obtain a fast convergence. Our simulation results show that the heuristic algorithm reduces the number of resident locations and the total moving distance. We also show that our proposed algorithm achieves a higher charging efficiency compared with existing algorithms.

  11. Extending Wireless Rechargeable Sensor Network Life without Full Knowledge

    Directory of Open Access Journals (Sweden)

    Najeeb W. Najeeb

    2017-07-01

    Full Text Available When extending the life of Wireless Rechargeable Sensor Networks (WRSN, one challenge is charging networks as they grow larger. Overcoming this limitation will render a WRSN more practical and highly adaptable to growth in the real world. Most charging algorithms require a priori full knowledge of sensor nodes’ power levels in order to determine the nodes that require charging. In this work, we present a probabilistic algorithm that extends the life of scalable WRSN without a priori power knowledge and without full network exploration. We develop a probability bound on the power level of the sensor nodes and utilize this bound to make decisions while exploring a WRSN. We verify the algorithm by simulating a wireless power transfer unmanned aerial vehicle, and charging a WRSN to extend its life. Our results show that, without knowledge, our proposed algorithm extends the life of a WRSN on average 90% of what an optimal full knowledge algorithm can achieve. This means that the charging robot does not need to explore the whole network, which enables the scaling of WRSN. We analyze the impact of network parameters on our algorithm and show that it is insensitive to a large range of parameter values.

  12. Materials issues in lithium ion rechargeable battery technology

    Energy Technology Data Exchange (ETDEWEB)

    Doughty, D.H.

    1995-07-01

    Lithium ion rechargeable batteries are predicted to replace Ni/Cd as the workhorse consumer battery. The pace of development of this battery system is determined in large part by the availability of materials and the understanding of interfacial reactions between materials. Lithium ion technology is based on the use of two lithium intercalating electrodes. Carbon is the most commonly used anode material, while the cathode materials of choice have been layered lithium metal chalcogenides (LiMX{sub 2}) and lithium spinel-type compounds. Electrolytes may be either organic liquids or polymers. Although the first practical use of graphite intercalation compounds as battery anodes was reported in 1981 for molten salt cells and in 1983 for ambient temperature systems, it was not until Sony Energytech announced a new lithium ion intercalating carbon anode in 1990, that interest peaked. The reason for this heightened interest is that these electrochemical cells have the high energy density, high voltage and light weight of metallic lithium, but without the disadvantages of dendrite formation on charge, improving their safety and cycle life.

  13. Groundwater Recharge and Hydrogeochemical Evolution in Leizhou Peninsula, China

    Directory of Open Access Journals (Sweden)

    Yintao Lu

    2015-01-01

    Full Text Available An analysis of the stable isotopes and the major ions in the surface water and groundwater in the Leizhou Peninsula was performed to identify the sources and recharge mechanisms of the groundwater. In this study, 70 water samples were collected from rivers, a lake, and pumping wells. The surface water was considered to have a lower salinity than the groundwater in the region of study. The regression equations for δD and δ18O for the surface water and the groundwater are similar to those for precipitation, indicating meteoric origins. The δD and δ18O levels in the groundwater ranged from −60‰; to −25‰; and −8.6‰; to −2.5‰, respectively, and were lower than the stable isotope levels from the winter and spring precipitation. The groundwater in the southern area was classified as the Ca2+-Mg2+-HCO3--type, whereas the groundwater in the northern area included three types (Na+-Cl−-type, Ca2+-Mg2+-HCO3--type, and Ca2+-Mg2+-Cl−-type, indicating rapid and frequent water-rock exchange in the region. A reasonable conclusion is that the groundwater chemistry is dominated by rock weathering and rainwater of local origin, which are influenced by seawater carried by the Asian monsoon.

  14. Joint Power Charging and Routing in Wireless Rechargeable Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jie Jia

    2017-10-01

    Full Text Available The development of wireless power transfer (WPT technology has inspired the transition from traditional battery-based wireless sensor networks (WSNs towards wireless rechargeable sensor networks (WRSNs. While extensive efforts have been made to improve charging efficiency, little has been done for routing optimization. In this work, we present a joint optimization model to maximize both charging efficiency and routing structure. By analyzing the structure of the optimization model, we first decompose the problem and propose a heuristic algorithm to find the optimal charging efficiency for the predefined routing tree. Furthermore, by coding the many-to-one communication topology as an individual, we further propose to apply a genetic algorithm (GA for the joint optimization of both routing and charging. The genetic operations, including tree-based recombination and mutation, are proposed to obtain a fast convergence. Our simulation results show that the heuristic algorithm reduces the number of resident locations and the total moving distance. We also show that our proposed algorithm achieves a higher charging efficiency compared with existing algorithms.

  15. Nanostructured silicon anodes for lithium ion rechargeable batteries.

    Science.gov (United States)

    Teki, Ranganath; Datta, Moni K; Krishnan, Rahul; Parker, Thomas C; Lu, Toh-Ming; Kumta, Prashant N; Koratkar, Nikhil

    2009-10-01

    Rechargeable lithium ion batteries are integral to today's information-rich, mobile society. Currently they are one of the most popular types of battery used in portable electronics because of their high energy density and flexible design. Despite their increasing use at the present time, there is great continued commercial interest in developing new and improved electrode materials for lithium ion batteries that would lead to dramatically higher energy capacity and longer cycle life. Silicon is one of the most promising anode materials because it has the highest known theoretical charge capacity and is the second most abundant element on earth. However, silicon anodes have limited applications because of the huge volume change associated with the insertion and extraction of lithium. This causes cracking and pulverization of the anode, which leads to a loss of electrical contact and eventual fading of capacity. Nanostructured silicon anodes, as compared to the previously tested silicon film anodes, can help overcome the above issues. As arrays of silicon nanowires or nanorods, which help accommodate the volume changes, or as nanoscale compliant layers, which increase the stress resilience of silicon films, nanoengineered silicon anodes show potential to enable a new generation of lithium ion batteries with significantly higher reversible charge capacity and longer cycle life.

  16. Effects of restricted recharge in an urban karst system

    Science.gov (United States)

    Toran, Laura; Gross, Kathleen; Yang, Youa

    2009-07-01

    Urban karst systems are typically considered more vulnerable to contamination and excess storm discharge because of potential source areas, increased sediment loading, and focusing of water from impervious surfaces. However, urban hydrology can lead to unexpected patterns, such as pirating of recharge into man-made storm systems. Valley Creek Basin in southeastern Pennsylvania, presents such an urban karst system. Four springs were monitored for suspended sediment, water chemistry, and storm response for an 18-month period. The baseflow suspended sediment concentrations were low, less than 4.0 mg/l. Furthermore, trace metal analysis of baseflow water samples and spring mouth sediment showed only low concentrations. The response to storms within the system was rapid, on the order of 1-3 h. The maximum water stage increases at the urban springs were typically less than 15 cm, with springs from more commercialized areas showing stormwater systems occurs. Thus, the concept of an urban karst system as a contaminant conduit is not the only one that applies. In Valley Creek Basin, reduced infiltration due to paving led to smaller storm response and less contaminant input, and the smaller capture area due to diversion of stormwater led to short flow paths and rapid storm response. Although contaminant levels have not increased due to urbanization, the springs may be at risk for future contamination. Short flow paths may reduce flushing, which means that the system will not cleanse itself if contamination occurs.

  17. A high-voltage rechargeable magnesium-sodium hybrid battery

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yifei; An, Qinyou; Cheng, Yingwen; Liang, Yanliang; Ren, Yang; Sun, Cheng-Jun; Dong, Hui; Tang, Zhongjia; Li, Guosheng; Yao, Yan

    2017-04-01

    Growing global demand of safe and low-cost energy storage technology triggers strong interests in novel battery concepts beyond state-of-art Li-ion batteries. Here we report a high-voltage rechargeable Mg–Na hybrid battery featuring dendrite-free deposition of Mg anode and Na-intercalation cathode as a low-cost and safe alternative to Li-ion batteries for large-scale energy storage. A prototype device using a Na3V2(PO4)3 cathode, a Mg anode, and a Mg–Na dual salt electrolyte exhibits the highest voltage (2.60 V vs. Mg) and best rate performance (86% capacity retention at 10C rate) among reported hybrid batteries. Synchrotron radiation-based X-ray absorption near edge structure (XANES), atomic-pair distribution function (PDF), and high-resolution X-ray diffraction (HRXRD) studies reveal the chemical environment and structural change of Na3V2(PO4)3 cathode during the Na ion insertion/deinsertion process. XANES study shows a clear reversible shift of vanadium K-edge and HRXRD and PDF studies reveal a reversible two-phase transformation and V–O bond length change during cycling. The energy density of the hybrid cell could be further improved by developing electrolytes with a higher salt concentration and wider electrochemical window. This work represents a significant step forward for practical safe and low-cost hybrid batteries.

  18. Extending Wireless Rechargeable Sensor Network Life without Full Knowledge

    Science.gov (United States)

    Najeeb, Najeeb W.; Detweiler, Carrick

    2017-01-01

    When extending the life of Wireless Rechargeable Sensor Networks (WRSN), one challenge is charging networks as they grow larger. Overcoming this limitation will render a WRSN more practical and highly adaptable to growth in the real world. Most charging algorithms require a priori full knowledge of sensor nodes’ power levels in order to determine the nodes that require charging. In this work, we present a probabilistic algorithm that extends the life of scalable WRSN without a priori power knowledge and without full network exploration. We develop a probability bound on the power level of the sensor nodes and utilize this bound to make decisions while exploring a WRSN. We verify the algorithm by simulating a wireless power transfer unmanned aerial vehicle, and charging a WRSN to extend its life. Our results show that, without knowledge, our proposed algorithm extends the life of a WRSN on average 90% of what an optimal full knowledge algorithm can achieve. This means that the charging robot does not need to explore the whole network, which enables the scaling of WRSN. We analyze the impact of network parameters on our algorithm and show that it is insensitive to a large range of parameter values. PMID:28714936

  19. Universal quinone electrodes for long cycle life aqueous rechargeable batteries

    Science.gov (United States)

    Liang, Yanliang; Jing, Yan; Gheytani, Saman; Lee, Kuan-Yi; Liu, Ping; Facchetti, Antonio; Yao, Yan

    2017-08-01

    Aqueous rechargeable batteries provide the safety, robustness, affordability, and environmental friendliness necessary for grid storage and electric vehicle operations, but their adoption is plagued by poor cycle life due to the structural and chemical instability of the anode materials. Here we report quinones as stable anode materials by exploiting their structurally stable ion-coordination charge storage mechanism and chemical inertness towards aqueous electrolytes. Upon rational selection/design of quinone structures, we demonstrate three systems that coupled with industrially established cathodes and electrolytes exhibit long cycle life (up to 3,000 cycles/3,500 h), fast kinetics (>=20C), high anode specific capacity (up to 200-395 mAh g-1), and several examples of state-of-the-art specific energy/energy density (up to 76-92 Wh kg-1/ 161-208 Wh l-1) for several operational pH values (-1 to 15), charge carrier species (H+, Li+, Na+, K+, Mg2+), temperature (-35 to 25 °C), and atmosphere (with/without O2), making them a universal anode approach for any aqueous battery technology.

  20. Extending Wireless Rechargeable Sensor Network Life without Full Knowledge.

    Science.gov (United States)

    Najeeb, Najeeb W; Detweiler, Carrick

    2017-07-17

    When extending the life of Wireless Rechargeable Sensor Networks (WRSN), one challenge is charging networks as they grow larger. Overcoming this limitation will render a WRSN more practical and highly adaptable to growth in the real world. Most charging algorithms require a priori full knowledge of sensor nodes' power levels in order to determine the nodes that require charging. In this work, we present a probabilistic algorithm that extends the life of scalable WRSN without a priori power knowledge and without full network exploration. We develop a probability bound on the power level of the sensor nodes and utilize this bound to make decisions while exploring a WRSN. We verify the algorithm by simulating a wireless power transfer unmanned aerial vehicle, and charging a WRSN to extend its life. Our results show that, without knowledge, our proposed algorithm extends the life of a WRSN on average 90% of what an optimal full knowledge algorithm can achieve. This means that the charging robot does not need to explore the whole network, which enables the scaling of WRSN. We analyze the impact of network parameters on our algorithm and show that it is insensitive to a large range of parameter values.

  1. Policy and Economics of Managed Aquifer Recharge and Water Banking

    Directory of Open Access Journals (Sweden)

    Sharon B. Megdal

    2015-02-01

    Full Text Available Managed Aquifer Recharge (MAR and water banking are of increasing importance to water resources management. MAR can be used to buffer against drought and changing or variable climate, as well as provide water to meet demand growth, by making use of excess surface water supplies and recycled waters. Along with hydrologic and geologic considerations, economic and policy analyses are essential to a complete analysis of MAR and water banking opportunities. The papers included in this Special Issue fill a gap in the literature by revealing the range of economic and policy considerations relevant to the development and implementation of MAR programs. They illustrate novel techniques that can be used to select MAR locations and the importance and economic viability of MAR in semi-arid to arid environments. The studies explain how MAR can be utilized to meet municipal and agricultural water demands in water-scarce regions, as well as assist in the reuse of wastewater. Some papers demonstrate how stakeholder engagement, ranging from consideration of alternatives to monitoring, and multi-disciplinary analyses to support decision-making are of high value to development and implementation of MAR programs. The approaches discussed in this collection of papers, along with the complementary and necessary hydrologic and geologic analyses, provide important inputs to water resource managers.

  2. Rechargeable aluminum batteries with conducting polymers as positive electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Hudak, Nicholas S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-12-01

    This report is a summary of research results from an Early Career LDRD project con-ducted from January 2012 to December 2013 at Sandia National Laboratories. Demonstrated here is the use of conducting polymers as active materials in the posi-tive electrodes of rechargeable aluminum-based batteries operating at room tempera-ture. The battery chemistry is based on chloroaluminate ionic liquid electrolytes, which allow reversible stripping and plating of aluminum metal at the negative elec-trode. Characterization of electrochemically synthesized polypyrrole films revealed doping of the polymers with chloroaluminate anions, which is a quasi-reversible reac-tion that facilitates battery cycling. Stable galvanostatic cycling of polypyrrole and polythiophene cells was demonstrated, with capacities at near-theoretical levels (30-100 mAh g-1) and coulombic efficiencies approaching 100%. The energy density of a sealed sandwich-type cell with polythiophene at the positive electrode was estimated as 44 Wh kg-1, which is competitive with state-of-the-art battery chemistries for grid-scale energy storage.

  3. Quantification of Groundwater Recharge from an Ephemeral Stream into a Mountainous Karst Aquifer

    Directory of Open Access Journals (Sweden)

    Noam Zach Dvory

    2018-01-01

    Full Text Available Sustainable groundwater production from karst aquifers is primarily dictated by its recharge rate. Therefore, it is essential to accurately quantify annual groundwater recharge in order to limit overexploitation and to evaluate artificial methods for groundwater enrichment. Infiltration during erratic flood events in karst basins may substantially contribute to aquifer recharge. However, the complicated nature of karst systems, which are characterized in part by multiple springs, sinkholes, and losing/gaining streams, impede accurate quantification of the actual contribution of flood waters to groundwater recharge. In this study, we aim to quantify the proportion of groundwater recharge accrued during runoff events in a karst aquifer. The role of karst conduits on flash flood infiltration was examined during four flood and controlled runoff events in the Soreq creek near Jerusalem, Israel. We distinguished between direct infiltration, percolation through karst conduits, and diffuse infiltration—the latter of which is most affected by evapotranspiration. A water balance was calculated for the 2014/15 hydrological year using the Hydrologic Engineering Center-Hydrologic Modelling System (HEC-HMS. Simulations show that 6.8 to 19.2% of the annual recharge volume was added to the aquifer from infiltration of runoff losses along the creek through the karst system.

  4. Analysis of groundwater migration from artificial recharge in a large urban aquifer: A simulation perspective

    Science.gov (United States)

    Tompson, Andrew F. B.; Carle, Steven F.; Rosenberg, Nina D.; Maxwell, Reed M.

    1999-10-01

    The increased use of reclaimed water for artificial groundwater recharge purposes has led to concerns about future groundwater quality, particularly as it relates to the introduction of new organic and inorganic contaminants into the subsurface. Here we review the development and initial application of a detailed numerical model of groundwater flow and migration in a region encompassing a large groundwater recharge operation in Orange County, California. The model is based upon a novel representation of geologic heterogeneity, which has long been known to influence local flow and transport behavior in the subsurface. The model and complementary series of isotopic analyses provide an improved scientific basis to understand flow paths, migration rates, and residence times of recharged groundwater, as well as to identify the source composition of water produced in wells near the recharge operation. From a management perspective these issues need to be confronted in order to respond to proposed regulatory constraints that would govern the operation of recharge facilities and nearby production wells. While model calibration is greatly aided by isotopic source and residence time analyses, the model also provides unique insights on the interpretation of isotopic data themselves. Isotopic estimates of groundwater age help discriminate between several equally acceptable simulations calibrated to head data only. However, the results also suggest that groundwater reaching a well spans a wide-ranging distribution of age, demonstrating the importance of geologic heterogeneity in affecting flow paths, mixing, and residence times in the vicinity of recharge basins and wells.

  5. Estimating Groundwater Recharge in the Semiarid Al-Khazir Gomal Basin, North Iraq

    Directory of Open Access Journals (Sweden)

    Hussein Jassas

    2014-08-01

    Full Text Available The mean annual recharge of Al-Khazir Gomal Basin was estimated as a basis for decision makers regarding the renewability and sustainability of groundwater. For this purpose, two approaches were used: hydrograph analysis and water table fluctuation (WTF. The long-term mean daily stream-flow records of Al-Khazir River (1969–1981 were used to estimate groundwater discharge by base-flow hydrograph separation and displacement recession curve methods. Four base-flow separation methods were used; one is the graphical separation method, and three are automated separation methods included in the web-based Hydrograph Analysis Tool. The annual recharge estimated by WTF was 111.6 mm/y, and the average annual recharge estimated by the four base-flow separation methods was 125.8 mm/y. Estimating recharge by the water table fluctuation method does not incorporate spatial variability contained in the whole watershed, because the specific yield did not represent the entire basin. However, the hydrograph analysis method can give a comprehensive estimation of the net integrated recharge for the entire watershed, which includes different recharge mechanisms. The displacement recession curve method deviates a lot (>30 mm/y from the other methods, which indicates that this method may not be suitable to apply in such large watersheds.

  6. Regional Assessment of Recharge Elevation of Tap Water Sources Using the Isoscape Approach

    Directory of Open Access Journals (Sweden)

    Tsutomu Yamanaka

    2017-05-01

    Full Text Available The importance of mountains as “natural water towers” has been quantified by comparing water budgets in upstream (mountain and downstream (lowland areas, but their importance for tap water supplies has not been assessed. Here, we propose an isoscape approach to estimate the mean recharge elevation of tap water sources (rivers, reservoirs, springs, and wells and apply it to a region in central Japan as a case study. Errors in the estimation of mean recharge elevation were estimated at 90–140 m. Results show that mean recharge elevations for about 90% of sources in the region are at 1000 m above sea level or higher. A little over half of the land area is above that elevation, while 98% of the population lives below it. These findings indicate that tap water disproportionally depends on recharge in mountains and is disproportionately supplied to lowland residents. Higher locations of spring water sources and longer (vertical distances of groundwater flow for well water sources make the recharge-to-population disproportionality more remarkable. Furthermore, our results suggest that larger cities require higher natural water towers to meet greater water demand, complemented by intermunicipal water suppliers. Some low-elevation municipalities depend heavily on water recharged in mountains well outside their territories. The method proposed here helps clarify how people depend on water supplies from mountains, providing essential knowledge for integrated management of mountains and water resources.

  7. Parameterization and quantification of recharge in crystalline fractured bedrocks in Galicia-Costa (NW Spain

    Directory of Open Access Journals (Sweden)

    J. R. Raposo

    2012-06-01

    Full Text Available Quantifying groundwater recharge in crystalline rocks presents great difficulties due to the high heterogeneity of the underground medium (mainly, due to heterogeneity in fracture network, which determines hydraulic parameters of the bedrock like hydraulic conductivity or effective porosity. Traditionally these rocks have been considered to have very low permeability, and their groundwater resources have usually been neglected; however, they can be of local importance when the bedrock presents a net of well-developed fractures. The current European Water Framework Directive requires an efficient management of all groundwater resources; this begins with a proper knowledge of the aquifer and accurate recharge estimation. In this study, an assessment of groundwater resources in the Spanish hydrologic district of Galicia-Costa, dominated by granitic and metasedimentary rocks, was carried out. A water-balance modeling approach was used for estimating recharge rates in nine pilot catchments representatives of both geologic materials. These results were cross-validated with an independent technique, i.e. the chloride mass balance (CMB. A relation among groundwater recharge and annual precipitation according to two different logistic curves was found for both granites and metasedimentary rocks, thus allowing the parameterization of recharge by means of only a few hydrogeological parameters. Total groundwater resources in Galicia-Costa were estimated to be 4427 hm3 yr−1. An analysis of spatial and temporal variability of recharge was also carried out.

  8. Sensitivity of groundwater recharge using climatic analogues and HYDRUS-1D

    Directory of Open Access Journals (Sweden)

    B. Leterme

    2012-08-01

    Full Text Available The sensitivity of groundwater recharge to different climate conditions was simulated using the approach of climatic analogue stations, i.e. stations presently experiencing climatic conditions corresponding to a possible future climate state. The study was conducted in the context of a safety assessment of a future near-surface disposal facility for low and intermediate level short-lived radioactive waste in Belgium; this includes estimation of groundwater recharge for the next millennia. Groundwater recharge was simulated using the Richards based soil water balance model HYDRUS-1D and meteorological time series from analogue stations. This study used four analogue stations for a warmer subtropical climate with changes of average annual precipitation and potential evapotranspiration from −42% to +5% and from +8% to +82%, respectively, compared to the present-day climate. Resulting water balance calculations yielded a change in groundwater recharge ranging from a decrease of 72% to an increase of 3% for the four different analogue stations. The Gijon analogue station (Northern Spain, considered as the most representative for the near future climate state in the study area, shows an increase of 3% of groundwater recharge for a 5% increase of annual precipitation. Calculations for a colder (tundra climate showed a change in groundwater recharge ranging from a decrease of 97% to an increase of 32% for four different analogue stations, with an annual precipitation change from −69% to −14% compared to the present-day climate.

  9. Multiple-method estimation of recharge rates at diverse locations in the North Carolina Coastal Plain, USA

    Science.gov (United States)

    Coes, A.L.; Spruill, T.B.; Thomasson, M.J.

    2007-01-01

    Recharge rates determined at diverse study sites in a shallow, unconfined aquifer differed from one another depending on the analytical method used and on each method's applicability and limitations. Total recharge was quantified with saturated-zone methods using water-table fluctuations at seven sites in North Carolina, USA and using groundwater-age dating at three of the seven sites; at two of the sites, potential recharge was quantified with an unsaturated-zone method using Darcy's law; and at five of the sites, net recharge was quantified with a stream hydrograph-separation method using streamflow-recession curves. Historical mean net recharge was 25 to 69% of the historical total recharge rates. The large disparity is attributed to groundwater losses between recharge and discharge areas, primarily by evapotranspiration and seepage to underlying aquifers. The spatial distribution of historical mean annual total recharge did not vary between landscape units, as suggested in a previous study. Similarly, total recharge did not correlate significantly with mean annual rainfall, mean annual water table depth, or the surficial soil properties of percent clay and bulk density. Total recharge did correlate significantly with the surficial soil properties of percent sand and percent silt. ?? Springer-Verlag 2007.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  12. Gas Sensor

    KAUST Repository

    Luebke, Ryan

    2015-01-22

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

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

    Science.gov (United States)

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

    2015-12-01

    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. 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. PEHB had the highest dentin bond strength (p0.1), but increased CaP release and re-release (p0.1). After the third cycle, specimens without further recharge had continuous CaP ion release for 2-3 weeks. 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 strength. Increasing NACP filler level increased the ion recharge and re-release capability. The new CaP recharge method and PMGDM-EBPADMA-NACP composition may have wide application in adhesives, composites and cements, to combat caries and remineralize lesions. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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 (p0.1), but increased CaP release and re-release (p0.1). 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 strength. Increasing NACP filler level increased the ion recharge and re-release capability. The new CaP recharge method and PMGDM-EBPAGMA-NACP composition may have wide application in adhesives, composites and cements, to combat caries and remineralize lesions. PMID:26144190

  15. Impact of climate variations on Managed Aquifer Recharge infiltration basins.

    Science.gov (United States)

    Barquero, Felix; Stefan, Catalin

    2017-04-01

    KEYWORDS: Managed Aquifer Recharge, field scale infiltration unit, climatic conditions, numerical model Managed Aquifer Recharge (MAR) is a technique that is gaining more attention as a sustainable alternative for areas where water scarcity is increasing. Main concept relies on facilitating the vertical infiltration of a source of fresh water (river water, rainwater, reclaimed water, etc). The groundwater acts as storage of water for further use in the future, for example in times of water scarcity. In some MAR types the soil itself can be used even as a filter for the removal of specific organic and inorganic compounds. In order to promote the benefits of MAR in different zones of the globe with variable climate conditions, including the effects of climate change, a numerical model (HYDRUS 2D/3D) is being set up. Coupled with the model a field-scale rapid infiltration unit (4m x 5m x 1.5m) was constructed with the capacity to log different MAR key parameters in the soil (tension, water content, temperature and electrical conductivity) in space and time. These data will feed the model for its calibration using specific hydrogeological characteristics of the packing material and hydraulic characteristics of the infiltrated fluid. The unit is located in the city of Pirna (German), 200 m north from the Elbe River where the groundwater level varies seasonally between 6 and 9 m below the ground surface. Together with the field scale rapid infiltration unit, a set of multi-parametric sensors (measuring in time: water stage, electrical conductivity, dissolved oxygen and temperature) in six monitoring wells, located on the basin surroundings, were installed. The purpose of these sensors is to estimate, via tracer experiments, the time that the infiltrated water needed to reach the groundwater and the flow speed in which it travelled once it reached the saturated zone. Once calibrated, the model will be able to estimate the flow behaviour under variable climate conditions

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

    Science.gov (United States)

    McMahon, P.B.; Plummer, L.N.; 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 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.

  17. Artificial-recharge tests in Upper Black Squirrel Creek basin, Jimmy Camp Valley, and Fountain Valley, El Paso County, Colorado

    Science.gov (United States)

    Emmons, P.J.

    1977-01-01

    Artificial-recharge tests were conducted in the alluvium in upper Black Squirrel Creek basin, the alluvium in Jimmy Camp Valley, and in the alluvium overlying the Widefield aquifer which is located in an ancestral channel in Fountain Valley, Colo. Nine artificial-recharge pits with areas of approximately 9,200 square feet each were excavated in the unsaturated zones above the three aquifers. Each artificial-recharge site was instrumented to measure inflow, stage fluctuations, and water-table fluctuations. Artificial-recharge tests of approximately 10 days ' duration were conducted at each of the nine artificial-recharge sites and one extended test of approximately 30 days ' duration was conducted in each of the three study areas. Periphyton growth, present in most of the artificial-recharge ponds, was insufficient to cause noticeable decline in the rate of infiltration. (Woodard-USGS)

  18. Vulnerability of Groundwater Recharge to Climate Change in an Alpine Basin (Martis Valley, California)

    Science.gov (United States)

    Visser, A.; Segal, D.; Urióstegui, S. H.; Singleton, M. J.; Moran, J. E.; Esser, B. K.

    2013-12-01

    Martis Valley's groundwater basin is experiencing increasing water demand and changes in the amount and timing of snowmelt due to climate change. Groundwater is the exclusive water supply for the town of Truckee and its surrounding ski resorts and golf courses. The objective of this study was to examine seasonal variability in the aquifer recharge by analyzing supply wells for: 1) tritium and helium isotopes to determine groundwater sources and age, 2) dissolved noble gases to determine recharge temperatures and excess air concentrations and 3) stable isotopes to determine groundwater sources. Recharge temperatures were found to be similar to mean annual air temperatures at lower elevations, suggesting that most recharge is occurring at lower elevations after equilibrating in the vadose zone. Low levels of excess air found in groundwater confirm that most recharge is occurring in the valley alluvium rather than the mountain block. The mean integrated groundwater flow depth was estimated for each well from the temperature difference between recharge and discharge and the geothermal gradient. Groundwater samples contained large amounts of excess terrigenic helium, from both mantle and radiogenic sources. Terrigenic helium and tritium concentrations were used to reconstruct the mixing between the younger and older groundwater sources. Mantle helium originating from the Polaris Fault was used to trace groundwater flow directions. Higher seasonal variability was found in wells with younger groundwater and shallower flow depths, suggesting that changes in the timing and amount of recharge under warmer climate conditions will rather quickly impact at least a portion of the aquifer system in Martis Valley. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

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

    Directory of Open Access Journals (Sweden)

    Nara Somaratne

    2015-02-01

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

  20. Field Investigation of a New Recharge Approach for ASR Projects in Near-Surface Aquifers.

    Science.gov (United States)

    Liu, Gaisheng; Knobbe, Steven; Reboulet, Edward C; Whittemore, Donald O; Händel, Falk; Butler, James J

    2016-05-01

    Aquifer storage and recovery (ASR) is the artificial recharge and temporary storage of water in an aquifer when water is abundant, and recovery of all or a portion of that water when it is needed. One key limiting factor that still hinders the effectiveness of ASR is the high costs of constructing, maintaining, and operating the artificial recharge systems. Here we investigate a new recharge method for ASR in near-surface unconsolidated aquifers that uses small-diameter, low-cost wells installed with direct-push (DP) technology. The effectiveness of a DP well for ASR recharge is compared with that of a surface infiltration basin at a field site in north-central Kansas. The performance of the surface basin was poor at the site due to the presence of a shallow continuous clay layer, identified with DP profiling methods, that constrained the downward movement of infiltrated water and significantly reduced the basin recharge capacity. The DP well penetrated through this clay layer and was able to recharge water by gravity alone at a much higher rate. Most importantly, the costs of the DP well, including both the construction and land costs, were only a small fraction of those for the infiltration basin. This low-cost approach could significantly expand the applicability of ASR as a water resources management tool to entities with limited fiscal resources, such as many small municipalities and rural communities. The results of this investigation demonstrate the great potential of DP wells as a new recharge option for ASR projects in near-surface unconsolidated aquifers. © 2015, National Ground Water Association.

  1. Climate variability and vadose zone controls on damping of transient recharge

    Science.gov (United States)

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

    2017-01-01

    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.

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

    Science.gov (United States)

    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.

  3. A methodology based on spatial distribution of parameters for understanding affect of rainfall and vegetation density on groundwater recharge

    OpenAIRE

    Vijai Singhal; Rohit Goyal

    2012-01-01

    Accurate estimation of groundwater recharge is extremely important for propermanagement of groundwater systems. Attempts have been made by various researchers torelate impact of various parameters on groundwater recharge. In the present study, amethodology based on spatial distribution of parameters has been developed forunderstanding affect of rainfall and vegetation density on groundwater recharge.Normalized Difference Vegetation Index (NDVI) has been used as an indicative parameterfor vege...

  4. Water Quality in the Equus Beds Aquifer and the Little Arkansas River Before Implementation of Large-Scale Artificial Recharge, South-Central Kansas, 1995-2005

    Science.gov (United States)

    Ziegler, Andrew C.; Hansen, Cristi V.; Finn, Daniel A.

    2010-01-01

    Artificial recharge of the Equus Beds aquifer using runoff from the Little Arkansas River in south-central Kansas was first proposed in 1956 and was one of many options considered by the city of Wichita to preserve its water supply. Declining aquifer water levels of as much as 50 feet exacerbated concerns about future water availability and enhanced migration of saltwater into the aquifer from past oil and gas activities near Burrton and from the Arkansas River. Because Wichita changed water-management strategies and decreased pumping from the Equus Beds aquifer in 1992, water storage in the aquifer recovered by about 50 percent. This recovery is the result of increased reliance on Cheney Reservoir for Wichita water supply, decreased aquifer pumping, and larger than normal precipitation. Accompanying the water-level recovery, the average water-level gradient in the aquifer decreased from about 12 feet per mile in 1992 to about 8 feet per mile in January 2006. An important component of artificial recharge is the water quality of the receiving aquifer and the water being recharged (source water). Water quality within the Little Arkansas River was defined using data from two real-time surface-water-quality sites and discrete samples. Water quality in the Equus Beds aquifer was defined using sample analyses collected at 38 index sites, each with a well completed in the shallow and deep parts of the Equus Beds aquifer. In addition, data were collected at diversion well sites, recharge sites, background wells, and prototype wells for the aquifer storage and recovery project. Samples were analyzed for major ions, nutrients, trace metals, radionuclides, organic compounds, and bacterial and viral indicators. Water-quality constituents of concern for artificial recharge are those constituents that frequently (more than 5 percent of samples) may exceed Federal [U.S. Environmental Protection Agency (USEPA)] and State drinking-water criteria in water samples from the receiving

  5. Compendium of Data for the Hanford Site (Fiscal Years 2004 to 2008) Applicable to Estimation of Recharge Rates

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, William E.; Rockhold, Mark L.; Downs, Janelle L.

    2008-09-24

    This report is a compendium of recharge data collected in Fiscal Years 2004 through 2008 at various soil and surface covers found and planned in the 200 West and 200 East Areas of the U.S. Department of Energy’s Hanford Site in southeast Washington State. The addition of these new data to previously published recharge data will support improved estimates of recharge with respect to location and soil cover helpful to evaluations and risk assessments of radioactive and chemical wastes at this site. Also presented are evaluations of the associated uncertainties, limitations, and data gaps in the existing knowledge base for recharge at the Hanford Site.

  6. Evaluation of drought impact on groundwater recharge rate using SWAT and Hydrus models on an agricultural island in western Japan

    Directory of Open Access Journals (Sweden)

    G. Jin

    2015-06-01

    Full Text Available Clarifying the variations of groundwater recharge response to a changing non-stationary hydrological process is important for efficiently managing groundwater resources, particularly in regions with limited precipitation that face the risk of water shortage. However, the rate of aquifer recharge is difficult to evaluate in terms of large annual-variations and frequency of flood events. In our research, we attempt to simulate related groundwater recharge processes under variable climate conditions using the SWAT Model, and validate the groundwater recharge using the Hydrus Model. The results show that annual average groundwater recharge comprised approximately 33% of total precipitation, however, larger variation was found for groundwater recharge and surface runoff compared to evapotranspiration, which fluctuated with annual precipitation variations. The annual variation of groundwater resources is shown to be related to precipitation. In spatial variations, the upstream is the main surface water discharge area; the middle and downstream areas are the main groundwater recharge areas. Validation by the Hydrus Model shows that the estimated and simulated groundwater levels are consistent in our research area. The groundwater level shows a quick response to the groundwater recharge rate. The rainfall intensity had a great impact on the changes of the groundwater level. Consequently, it was estimated that large spatial and temporal variation of the groundwater recharge rate would be affected by precipitation uncertainty in future.

  7. Application of the rainfall infiltration breakthrough (RIB) model for groundwater recharge estimation in west coastal South Africa

    CSIR Research Space (South Africa)

    Sun, X

    2013-04-01

    Full Text Available (CMB) approach, and a value of 5% using a GIS-based groundwater recharge algorithm, and a value of 13% in the vicinity of Riverlands (DWAF, 2006). Another study in the area reported recharge values of 26% of rainfall (380 mm/a) using a water balance... method at Atlantis (20 km south of Riverlands) (Vandoolaeghe and Bertram, 1982). Bredenkamp (1982) modelled the conditions at Atlantis and came up with a recharge rate of 21% of total rainfall (350 mm/a). The recharge rate was reconsidered as 0...

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

    Science.gov (United States)

    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.

  9. Three-dimensional inversion of in-line resistivity data for monitoring a groundwater recharge experiment in a pyroclastic plateau

    Science.gov (United States)

    Inoue, Keisuke; Nakazato, Hiroomi; Kubota, Tomijiro; Takeuchi, Mutsuo; Sugimoto, Yoshihiro; Kim, Hee Joon; Furue, Koji

    2017-06-01

    An artificial groundwater recharge experiment was conducted in a pyroclastic plateau in Kagoshima Prefecture in Japan, and time-lapse electrical resistivity data were collected to monitor the recharge process. In the experiment, time-efficient in-line resistivity surveys were performed along four intersecting lines, because a large amount of water was released from two recharge areas and a relatively fast migration of water into the vadose zone was expected. The migration of recharged water may be estimated from changes in electrical resistivity because resistivity in the vadose zone is largely controlled by water saturation variations there. The geological setting at the experiment site was interpreted from the resistivity distribution inverted from the in-line survey data, which were obtained before the recharge experiment. The resistivity distribution showed an approximately layered structure, which could be correlated with four borehole logs in the area. Three-dimensional (3D) distributions of the resistivity change ratio were derived through constrained nonlinear ratio inversion. Three-dimensional inversion of the in-line resistivity data was more suitable than two-dimensional inversion to describe the 3D phenomena associated with groundwater recharge. During the recharge experiment, the zones of decreased resistivity shifted with time, indicating non-uniform penetration of water from the recharge areas into the ground and a horizontal flow of the recharged water, especially in the secondary Shirasu layer, which comprises lacustrine or marine sediments of pyroclastic origin. These interpretations agree with the variation in water content observed in a borehole.

  10. Estimation of Relative Recharge Sequence to Groundwater with Minimum Entropy Deconvolution

    Science.gov (United States)

    Kim, T.; Lee, K.

    2002-12-01

    Groundwater is widely used as natural resources for the drink, spa, etc., and a supplement to the official and/or natural water supply. In these cases, the establishment of water balance model can provide a safe and effective usage of resources. To establish the appropriate water balance model and the design of water usage, recharge rate must be estimated with an allowed accuracy. For these purposes, many methods were suggested to estimate recharge rate. One of most popular methods in recent years is measuring groundwater age with environmental tracer(Solomon et. al., 1993; Leduc et. al., 1997; Bromley et. al., 1997; Williams, 1997; Ayalon et. al. 1998). Using the distributed environmental tracer, the vertical profile of groundwater age can be composed, and recharge rate can be estimated with the composed profile. Water budget analysis can be the other one of available method(Bradbury and Rushton, 1998; Finch, 1998; Bekesi and McConchie, 1999). However, to explain the expansion of contaminant with temporal variation of unsaturated flow, sequential estimation of recharge must be needed. Unfortunately, it is a very hard work to find out some studies on sequential approaches to estimate the recharge rate to groundwater. Even predictive deconvolution technique was rarely. In general, minimum phase condition, preposition of classical predictive deconvolution, can hardly be satisfied in nature. On the contrary, the input signal in natural system can be considered as a random signal. To avoid the strong restriction of minimum phase condition, Wiggins(1978) proposed minimum entropy deconvolution(MED) with varimax norm. However, solution process with varimax norm is non-linear. For the linearization of MED problem, Carbrelli suggested another criterion, D norm(1984). In this study, MED with D norm was applied to the estimation of the sequence of relative recharge rate, and the applicability of MED to evaluation of recharge sequence was investigated. To check out the

  11. Gas gangrene

    Science.gov (United States)

    Tissue infection - Clostridial; Gangrene - gas; Myonecrosis; Clostridial infection of tissues; Necrotizing soft tissue infection ... Gas gangrene is most often caused by bacteria called Clostridium perfringens. It also can be caused by ...

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

    Directory of Open Access Journals (Sweden)

    Spannenberg Jescica

    2017-09-01

    Full Text Available 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  16. Programs for calibration-based Monte Carlo simulation of recharge areas.

    Science.gov (United States)

    Starn, J Jeffrey; Bagtzoglou, Amvrossios C

    2012-01-01

    One use of groundwater flow models is to simulate contributing recharge areas to wells or springs. Particle tracking can be used to simulate these recharge areas, but in many cases the modeler is not sure how accurate these recharge areas are because parameters such as hydraulic conductivity and recharge have errors associated with them. The scripts described in this article (GEN_LHS and MCDRIVER_LHS) use the Python scripting language to run a Monte Carlo simulation with Latin hypercube sampling where model parameters such as hydraulic conductivity and recharge are randomly varied for a large number of model simulations, and the probability of a particle being in the contributing area of a well is calculated based on the results of multiple simulations. Monte Carlo simulation provides one useful measure of the variability in modeled particles. The Monte Carlo method described here is unique in that it uses parameter sets derived from the optimal parameters, their standard deviations, and their correlation matrix, all of which are calculated during nonlinear regression model calibration. In addition, this method uses a set of acceptance criteria to eliminate unrealistic parameter sets. Ground Water © 2011, National Ground Water Association. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

  17. Surface clogging process modeling of suspended solids during urban stormwater aquifer recharge.

    Science.gov (United States)

    Wang, Zijia; Du, Xinqiang; Yang, Yuesuo; Ye, Xueyan

    2012-01-01

    Aquifer recharge, which uses urban stormwater, is an effective technique to control the negative effects of groundwater over-exploitation, while clogging problems in infiltration systems remain the key restricting factor in broadening its practice. Quantitative understanding of the clogging process is still very poor. A laboratory study was conducted to understand surface physical clogging processes, with the primary aim of developing a model for predicting suspended solid clogging processes before aquifer recharge projects start. The experiments investigated the clogging characteristics of different suspended solid sizes in recharge water by using a series of one-dimensional fine quartz sand columns. The results showed that the smaller the suspended particles in recharge water, the farther the distance of movement and the larger the scope of clogging in porous media. Clogging extents in fine sand were 1 cm, for suspended particle size ranging from 0.075 to 0.0385 mm, and 2 cm, for particles less than 0.0385 mm. In addition, clogging development occurred more rapidly for smaller suspended solid particles. It took 48, 42, and 36 hr respectively, for large-, medium-, and small-sized particles to reach pre-determined clogging standards. An empirical formula and iteration model for the surface clogging evolution process were derived. The verification results obtained from stormwater recharge into fine sand demonstrated that the model could reflect the real laws of the surface clogging process.

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

    Science.gov (United States)

    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.

  19. Policy Preferences about Managed Aquifer Recharge for Securing Sustainable Water Supply to Chennai City, India

    Directory of Open Access Journals (Sweden)

    Norbert Brunner

    2014-12-01

    Full Text Available The objective of this study is to bring out the policy changes with respect to managed aquifer recharge (focusing on infiltration ponds, which in the view of relevant stakeholders may ease the problem of groundwater depletion in the context of Chennai City; Tamil Nadu; India. Groundwater is needed for the drinking water security of Chennai and overexploitation has resulted in depletion and seawater intrusion. Current policies at the municipal; state and national level all support recharge of groundwater and rainwater harvesting to counter groundwater depletion. However, despite such favorable policies, the legal framework and the administrative praxis do not support systematic approaches towards managed aquifer recharge in the periphery of Chennai. The present study confirms this, considering the mandates of governmental key-actors and a survey of the preferences and motives of stakeholder representatives. There are about 25 stakeholder groups with interests in groundwater issues, but they lack a common vision. For example, conflicting interest of stakeholders may hinder implementation of certain types of managed aquifer recharge methods. To overcome this problem, most stakeholders support the idea to establish an authority in the state for licensing groundwater extraction and overseeing managed aquifer recharge.

  20. Fluoride release and recharging ability of new dental sealants.

    Science.gov (United States)

    Dionysopoulos, D; Sfeikos, T; Tolidis, K

    2016-02-01

    This in vitro investigation was to evaluate the fluoride release and recharge abilities of three recently introduced dental fissure sealants (FS). Three dental FS were assessed: Teethmate F-1 (Kuraray), Fissurit F (Voco), BeautiSealant (Shofu), and a conventional glass ionomer cement FX-II (Shofu) as a control. Eight cylindrical specimens (7 × 2 mm) of each material were made and immersed individually in 5 ml de-ionized water in plastic containers. Fluoride release of the tested materials was evaluated during the experimental period (28 days) utilising a fluoride ion-selective electrode. At the end of the test period, the specimens were soaked for 5 min in a fluoride solution (0.05 % NaF) and fluoride release was evaluated for the next 5 days. The data were statistically analysed using one-way ANOVA and Bonferroni post hoc test and the level of significance was preset at α = 0.05. The total fluoride release over the 28-day period for each material was: FX-II (408.6 ± 45.66 μg/cm(2)) > Teethmate F-1 (89.45 ± 12.32 μg/cm(2)) > Fissurit F (68.62 ± 8.72 μg/cm(2)) > BeautiSealant (33.32 ± 4.91 μg/cm(2)), (p  Teethmate F-1 (9.76 ± 1.62 μg/cm(2)) > BeautiSealant (5.69 ± 0.89 μg/cm(2)) > Fissurit F (4.76 ± 0.72 μg/cm(2)), (p sealants exhibited different capabilities to release and uptake fluoride ions after re-fluoridation but significantly lower than the glass ionomer tested.

  1. Ruslands Gas

    OpenAIRE

    Elkjær, Jonas Bondegaard

    2008-01-01

    This paper is about Russian natural gas and the possibility for Russia to use its reserves of natural gas politically towards the European Union to obtain some political power. Russia owns 32,1 % of the world gas reserves, and The European Union is getting 50 % of its gas import from Russia. I will use John Mearsheimer’s theory ”The Tragedy of Great Power Politics” to explain how Russia can use its big reserves of gas on The European Union to get political influence.

  2. Extreme flood event analysis in Indonesia based on rainfall intensity and recharge capacity

    Science.gov (United States)

    Narulita, Ida; Ningrum, Widya

    2018-02-01

    Indonesia is very vulnerable to flood disaster because it has high rainfall events throughout the year. Flood is categorized as the most important hazard disaster because it is causing social, economic and human losses. The purpose of this study is to analyze extreme flood event based on satellite rainfall dataset to understand the rainfall characteristic (rainfall intensity, rainfall pattern, etc.) that happened before flood disaster in the area for monsoonal, equatorial and local rainfall types. Recharge capacity will be analyzed using land cover and soil distribution. The data used in this study are CHIRPS rainfall satellite data on 0.05 ° spatial resolution and daily temporal resolution, and GSMap satellite rainfall dataset operated by JAXA on 1-hour temporal resolution and 0.1 ° spatial resolution, land use and soil distribution map for recharge capacity analysis. The rainfall characteristic before flooding, and recharge capacity analysis are expected to become the important information for flood mitigation in Indonesia.

  3. An approach to delineate groundwater recharge potential sites in Ambalantota, Sri Lanka using GIS techniques

    Directory of Open Access Journals (Sweden)

    I.P. Senanayake

    2016-01-01

    Full Text Available The demand for fresh water in Hambantota District, Sri Lanka is rapidly increasing with the enormous amount of ongoing development projects in the region. Nevertheless, the district experiences periodic water stress conditions due to seasonal precipitation patterns and scarcity of surface water resources. Therefore, management of available groundwater resources is critical, to fulfil potable water requirements in the area. However, exploitation of groundwater should be carried out together with artificial recharging in order to maintain the long term sustainability of water resources. In this study, a GIS approach was used to delineate potential artificial recharge sites in Ambalantota area within Hambantota. Influential thematic layers such as rainfall, lineament, slope, drainage, land use/land cover, lithology, geomorphology and soil characteristics were integrated by using a weighted linear combination method. Results of the study reveal high to moderate groundwater recharge potential in approximately 49% of Ambalantota area.

  4. What controls the partitioning between baseflow and mountain block recharge in the Qinghai-Tibet Plateau?

    Science.gov (United States)

    Yao, Yingying; Zheng, Chunmiao; Andrews, Charles; Zheng, Yi; Zhang, Aijing; Liu, Jie

    2017-08-01

    Mountainous areas are referred to as "water towers" since they are the source of water for many low-lying communities. The hydrologic budgets of these areas, which are particularly susceptible to climate change, are typically poorly constrained. To address this, we analyzed the partitioning between baseflow and mountain block recharge (MBR) using a regional groundwater model of the northern Qinghai-Tibet Plateau run with multiple scenarios. We found that 19% of precipitation is recharged, approximately 35% of which becomes MBR, while 65% discharges as baseflow. This partitioning is relatively independent of the recharge rate but is sensitive to exponential depth decrease of hydraulic conductivity (K). The MBR is more sensitive to this exponential decrease in K than baseflow. The proportion of MBR varies from twice to half of baseflow as the decay exponent increases by more than fivefold. Thus, the depth dependence of K is critical for quantifying hydrologic partitioning in these sensitive areas.

  5. PEMETAAN DATA RECHARGE AIR TANAH DI KABUPATEN SLEMAN BERDASARKAN DATA CURAH HUJAN

    Directory of Open Access Journals (Sweden)

    Bambang Yuwono

    2017-01-01

    The method used in this research is the Water Balance (keseimbangan airmethod. This method is based on any incoming rain water will be equal to the output evapotranspiration and runoff hereinafter this method is applied in the application. Factors affecting groundwater recharge the water balance method is precipitation, evapotranspiration and run off. Information og groundwater recharge is also displayed on the map using Google Map function are related to the database system to produce informative mapsCalculation of groundwater recharge is applied to the daily rainfall data input into the application which then included in the water balance equation method so it can be easy to determine the value of groundwater recharge. Groundwater recharge information can be displayed in the form of mapping, making them easier to understand visually.Based on testing, the highest recharge results of this research on the Kemput station is 1119,5 mm/year with rainfall of 2750 mm/year. Seyegan and Bronggang station is 1026,25 mm/year with rainfall of 2625 mm/year. Angin-angin and Prumpung station is 933 mm/year with rainfall of 2500 mm/year. Beran and Gemawang station is 839.5 mm/year with rainfall of 2375 mm/year. Plataran station is 808.42 mm/year with rainfall of 2333 mm/year. Godean station is 699.5 mm/year with rainfall of 2187 mm/year and the lowest at Tirto Tanjungand Santan stastion 560 mm / year with rainfall of 2000 mm / year.

  6. Method of preparing graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes

    Science.gov (United States)

    Liu, Jun; Lemmon, John P; Yang, Zhenguo; Cao, Yuliang; Li, Xiaolin

    2015-04-07

    A method of preparing a graphene-sulfur nanocomposite for a cathode in a rechargeable lithium-sulfur battery comprising thermally expanding graphite oxide to yield graphene layers, mixing the graphene layers with a first solution comprising sulfur and carbon disulfide, evaporating the carbon disulfide to yield a solid nanocomposite, and grinding the solid nanocomposite to yield the graphene-sulfur nanocomposite. Rechargeable-lithium-sulfur batteries having a cathode that includes a graphene-sulfur nanocomposite can exhibit improved characteristics. The graphene-sulfur nanocomposite can be characterized by graphene sheets with particles of sulfur adsorbed to the graphene sheets. The sulfur particles have an average diameter of less than 50 nm.

  7. Carbyne Polysulfide as a Novel Cathode Material for Rechargeable Magnesium Batteries

    Directory of Open Access Journals (Sweden)

    Yanna NuLi

    2014-01-01

    Full Text Available We report the formation of carbyne polysulfide by coheating carbon containing carbyne moieties and elemental sulfur. The product is proved to have a sp2 hybrid carbon skeleton with polysulfide attached on it. The electrochemical performance of carbyne polysulfide as a novel cathode material for rechargeable magnesium batteries is firstly investigated. The material exhibits a high discharge capacity of 327.7 mAh g−1 at 3.9 mA g−1. These studies show that carbyne polysulfide is a promising candidate as cathode material for rechargeable Mg batteries if the capacity retention can be significantly improved.

  8. Carbyne polysulfide as a novel cathode material for rechargeable magnesium batteries.

    Science.gov (United States)

    NuLi, Yanna; Chen, Qiang; Wang, Weikun; Wang, Ying; Yang, Jun; Wang, Jiulin

    2014-01-01

    We report the formation of carbyne polysulfide by coheating carbon containing carbyne moieties and elemental sulfur. The product is proved to have a sp2 hybrid carbon skeleton with polysulfide attached on it. The electrochemical performance of carbyne polysulfide as a novel cathode material for rechargeable magnesium batteries is firstly investigated. The material exhibits a high discharge capacity of 327.7 mAh g(-1) at 3.9 mA g(-1). These studies show that carbyne polysulfide is a promising candidate as cathode material for rechargeable Mg batteries if the capacity retention can be significantly improved.

  9. Ecotoxicity assessment of artificial groundwater recharge with reclaimed water: a pilot-scale study.

    Science.gov (United States)

    Zhang, Xue; Zhao, Xuan

    2013-11-01

    A demonstration of artificial groundwater recharge with tertiary effluent was evaluated using a set of bioassays (acute toxicity to Daphnia, genotoxicity, estrogenic and antiestrogenic toxicity). Around 95 % genotoxicity and 53 % antiestrogenicity were removed from the feed water by ozonation, whereas significant reduction of acute toxicity to Daphnia magna was achieved during a 3 days vadose soil treatment. The toxicity was further removed to the same level as the local groundwater during a 20 days aquifer soil treatment. The pilot study has shown that ozonation and soil treatments can improve the quality of municipal wastewater treatment plant effluents for possible groundwater recharge purposes.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  12. Uncertainty of Coupled Soil-Vegetation-Atmosphere Modelling Methods for Estimating Groundwater Recharge

    Science.gov (United States)

    Xie, Y.; Cook, P. G.; Simmons, C. T.; Partington, D.; Crosbie, R.; Batelaan, O.

    2016-12-01

    Coupled soil-vegetation-atmosphere models have become increasingly popular for estimating groundwater recharge, because of the integration of carbon, energy and water balances. The carbon and energy balances act to constrain the water balance and as a result should reduce the uncertainty of groundwater recharge estimates. However, the addition of carbon and energy balances also introduces a large number of plant physiological parameters which complicates the estimation of groundwater recharge. Moreover, this method often relies on existing pedotransfer functions to derive soil water retention curve parameters and saturated hydraulic conductivity from soil attribute data. The choice of a pedotransfer function is usually subjective and several pedotransfer functions may be fit for the purpose. These different pedotransfer functions (and thus the uncertainty of soil water retention curve parameters and saturated hydraulic conductivity) are likely to increase the prediction uncertainty of recharge estimates. In this study, we aim to assess the potential uncertainty of groundwater recharge when using a coupled soil-vegetation-atmosphere modelling method. The widely used WAter Vegetation Energy and Solute (WAVES) modelling code was used to perform simulations of different water balances in order to estimate groundwater recharge in the Campaspe catchment in southeast Australia. We carefully determined the ranges of the vegetation parameters based upon a literature review. We also assessed a number of existing pedotransfer functions and selected the four most appropriate. Then the Monte Carlo analysis approach was employed to examine potential uncertainties introduced by different types of errors. Preliminary results suggest that for a mean rainfall of about 500 mm/y and annual pasture vegetation, the estimated recharge may range from 10 to 150 mm/y due to the uncertainty in vegetation parameters. This upper bound of the recharge range may double to 300 mm/y if different

  13. Flexible Rechargeable Zinc-Air Batteries through Morphological Emulation of Human Hair Array.

    Science.gov (United States)

    Fu, Jing; Hassan, Fathy Mohamed; Li, Jingde; Lee, Dong Un; Ghannoum, Abdul Rahman; Lui, Gregory; Hoque, Md Ariful; Chen, Zhongwei

    2016-08-01

    An electrically rechargeable, nanoarchitectured air electrode that morphologically emulates a human hair array is demonstrated in a zinc-air battery. The hair-like array of mesoporous cobalt oxide nanopetals in nitrogen-doped carbon nanotubes is grown directly on a stainless-steel mesh. This electrode produces both flexibility and improved battery performance, and thus fully manifests the advantages of flexible rechargeable zinc-air batteries in practical applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Geologic framework and hydrogeologic characteristics of the Edwards Aquifer recharge zone, Bexar County, Texas

    Science.gov (United States)

    Stein, W.G.; Ozuna, G.B.

    1995-01-01

    In Bexar County, residential and commercial development on the Edwards aquifer recharge zone is increasing. The aquifer possibly can be contaminated by spills, leakage of hazardous materials, or runoff from the rapidly developing urban areas that surround, or are built on, the intensely faulted and fractured, karstic limestone outcrops characteristic of the recharge zone. Furthermore, some of the hydrogeologic subdivisions that compose the Edwards aquifer have greater effective porosity than others. The areas where the most porous subdivisions crop out might provide efficient avenues for contaminants to enter the aquifer.

  15. High-performance rechargeable batteries with nanoparticle active materials, photochemically regenerable active materials, and fast solid-state ion conductors

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, Joseph C.

    2017-04-04

    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.

  16. Application Of Water Table Fluctuation Method To Quantify Spatial Groundwater Recharge Witidn The Southern Slope Of Merapi Volcano, Indonesia

    Directory of Open Access Journals (Sweden)

    Tjahyo Nugroho Adji

    2013-07-01

    that results in groundwater recharge characteristic. The volcanic slope unit (above 600 m as! has the lowest water table fluctuation indicates the resistant comportment to the annual rainfall. Ihis unit is characterized by the relatively high magnitude of recharge of approximately 4270 mm/year.

  17. Modelling the effects of climate and land cover change on groundwater recharge in south-west Western Australia

    National Research Council Canada - National Science Library

    Dawes, W; Ali, R; Varma, S; Emelyanova, I; Hodgson, G; McFarlane, D

    2012-01-01

    .... There is expected to be a reduction of diffuse recharge across the Swan Coastal Plain. This study aims to quantify the change in groundwater recharge in response to a range of future climate and land cover patterns across south-west Western Australia...

  18. Water Chemistry Impacts on Arsenic Mobilization from Arsenopyrite Dissolution and Secondary Mineral Precipitation: Implications for Managed Aquifer Recharge

    Science.gov (United States)

    Managed Aquifer Recharge (MAR) is one water reuse technique with the potential to meet growing water demands. However, MAR sites have encountered arsenic remobilization resulting from recharge operations. To combat this challenge, it is important to identify the mechanism of arse...

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

    Science.gov (United States)

    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/m3 and 1500-5600 Bq/m3, 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.

  20. Pre- and post-reservoir ground-water conditions and assessment of artificial recharge at Sand Hollow, Washington County, Utah, 1995-2005

    Science.gov (United States)

    Heilweil, Victor M.; Susong, David D.; Gardner, Philip M.; Watt, Dennis E.

    2005-01-01

    Sand Hollow, Utah, is the site of a surface-water reservoir completed in March 2002, which is being operated by the Washington County Water Conservancy District primarily as an aquifer storage and recovery project. The reservoir is an off-channel facility receiving water from the Virgin River, diverted near the town of Virgin, Utah. It is being operated conjunctively, providing both surface-water storage and artificial recharge to the underlying Navajo aquifer. The U.S. Geological Survey and the Bureau of Reclamation conducted a study to document baseline ground-water conditions at Sand Hollow prior to the operation of the reservoir and to evaluate changes in ground-water conditions caused by the reservoir.Pre-reservoir age dating using tritium/helium, chlorofluorocarbons, and carbon-14 shows that shallow ground water in the Navajo Sandstone in some areas of Sand Hollow entered the aquifer from 2 to 25 years before sample collection. Ground water in low-recharge areas and deeper within the aquifer may have entered the aquifer more than 8,000 years ago. Ground-water levels in the immediate vicinity of Sand Hollow Reservoir have risen by as much as 80 feet since initial filling began in March 2002. In 2005, ground water was moving laterally away from the reservoir in all directions, whereas the pre-reservoir direction of ground-water flow was predominantly toward the north.Tracers, or attributes, of artificial recharge include higher specific conductance, higher dissolved-solids concentrations, higher chloride-to-bromide ratios, more-depleted stable isotopes (2H and 18O), and higher total-dissolved gas pressures. These tracers have been detected at observation and production wells close to the reservoir. About 15,000 tons of naturally occurring salts that previously accumulated in the vadose zone beneath the reservoir are being flushed into the aquifer. Except for the shallowest parts of the aquifer, this is generally not affecting water quality, largely because of

  1. Understanding Conversion-Type Electrodes for Lithium Rechargeable Batteries.

    Science.gov (United States)

    Yu, Seung-Ho; Feng, Xinran; Zhang, Na; Seok, Jeesoo; Abruña, Héctor D

    2018-02-20

    , sulfides, fluorides, phosphides, and nitrides can undergo conversion reactions yielding materials with high theoretical capacity (generally from 500 to 1500 mA h g -1 ). In particular, a number of transition metal oxides and sulfides have shown excellent electrochemical properties as high-capacity anode materials. In addition, some transition metal fluorides have shown great potential as cathode materials for Li rechargeable batteries. In this Account we present mechanistic studies, with emphasis on the use of operando methods, of selected examples of conversion-type materials as both potentially high-energy-density anodes and cathodes in EES applications. We also include examples of the conceptually similar conversion-type reactions involving chalcogens and halogens, with emphasis on the Li-S system. In this case we focus on the problems arising from the low electrical conductivities of elemental sulfur and Li 2 S and the "redox shuttle" phenomena of polysulfides. In addition to mechanistic insights from the use of operando methods, we also cover several key strategies in electrode materials design such as controlling the size, morphology, composition, and architecture.

  2. Assessment of future impacts of potential climate change scenarios on aquifer recharge in continental Spain

    Science.gov (United States)

    Pulido-Velazquez, David; Collados-Lara, Antonio-Juan; Alcalá, Francisco J.

    2017-04-01

    This research proposes and applies a method to assess potential impacts of future climatic scenarios on aquifer rainfall recharge in wide and varied regions. The continental Spain territory was selected to show the application. The method requires to generate future series of climatic variables (precipitation, temperature) in the system to simulate them within a previously calibrated hydrological model for the historical data. In a previous work, Alcalá and Custodio (2014) used the atmospheric chloride mass balance (CMB) method for the spatial evaluation of average aquifer recharge by rainfall over the whole of continental Spain, by assuming long-term steady conditions of the balance variables. The distributed average CMB variables necessary to calculate recharge were estimated from available variable-length data series of variable quality and spatial coverage. The CMB variables were regionalized by ordinary kriging at the same 4976 nodes of a 10 km x 10 km grid. Two main sources of uncertainty affecting recharge estimates (given by the coefficient of variation, CV), induced by the inherent natural variability of the variables and from mapping were segregated. Based on these stationary results we define a simple empirical rainfall-recharge model. We consider that spatiotemporal variability of rainfall and temperature are the most important climatic feature and variables influencing potential aquifer recharge in natural regime. Changes in these variables can be important in the assessment of future potential impacts of climatic scenarios over spatiotemporal renewable groundwater resource. For instance, if temperature increases, actual evapotranspitration (EA) will increases reducing the available water for others groundwater balance components, including the recharge. For this reason, instead of defining an infiltration rate coefficient that relates precipitation (P) and recharge we propose to define a transformation function that allows estimating the spatial

  3. Dongfang 1-1 gas field in the mud diapir belt of the Yinggehai Basin, South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Zhenfeng, Wang [CNOOC Ltd.-Zhanjiang, Guangdong 524057 (China); Baojia, Huang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); CNOOC Ltd.-Zhanjiang, Guangdong 524057 (China)

    2008-04-15

    The Dongfang 1-1 (DF1-1) mud diapir field is the largest gas field discovered in the Yinggehai Basin up to now, with a proven gas reserve of 99.68 x 10{sup 9} m{sup 3}. The gas pay zones are within the Pliocene fine sandstones and siltstones of the littoral and sand bar facies, with normal pressure regimes. The gases include variable amounts of CO{sub 2} and N{sub 2} in addition to hydrocarbon gases. The hydrocarbon gases (with the exception of biogenic methane) and nitrogen originated from the marine source rocks within the overpressured Lower to Middle Miocene strata, while CO{sub 2} is most likely the product of thermal decomposition of the Tertiary calcareous mudstones and pre-Tertiary carbonates through relatively long-distance vertical migration. The field has received at least four phases of natural gas charging occurring relatively late, most likely during the post-Pliocene Himalayan orogeny. Diapiric faults act as the main conduit for upward movement of fluids released from the deep high-pressure system, with abnormally high pressures providing the significant driving force for gas migration. Because of the episodic nature of the deep high-pressured fluid release and the diapir fault activity, this shallow diapir gas field is characterized by multiple gas sources and episodic fluid accumulation. (author)

  4. Requirements for gas quality and gas appliances

    NARCIS (Netherlands)

    Levinsky, Howard; Gersen, Sander; Kiewiet, Bert

    2015-01-01

    Introduction The gas transmission network in the Netherlands transports two different qualities of gas, low-calorific gas known as G-gas or L-gas and, high calorific gas (H-gas). These two gas qualities are transported in separate networks, and are connected by means of five blending and conversion

  5. A membrane inlet mass spectrometry system for noble gases at natural abundances in gas and water samples.

    Science.gov (United States)

    Visser, Ate; Singleton, Michael J; Hillegonds, Darren J; Velsko, Carol A; Moran, Jean E; Esser, Bradley K

    2013-11-15

    Noble gases dissolved in groundwater can reveal paleotemperatures, recharge conditions, and precise travel times. The collection and analysis of noble gas samples are cumbersome, involving noble gas purification, cryogenic separation and static mass spectrometry. A quicker and more efficient sample analysis method is required for introduced tracer studies and laboratory experiments. A Noble Gas Membrane Inlet Mass Spectrometry (NG-MIMS) system was developed to measure noble gases at natural abundances in gas and water samples. The NG-MIMS system consists of a membrane inlet, a dry-ice water trap, a carbon-dioxide trap, two getters, a gate valve, a turbomolecular pump and a quadrupole mass spectrometer equipped with an electron multiplier. Noble gases isotopes (4)He, (22)Ne, (38)Ar, (84)Kr and (132)Xe are measured every 10 s. The NG-MIMS system can reproduce measurements made on a traditional noble gas mass spectrometer system with precisions of 2%, 8%, 1%, 1% and 3% for He, Ne, Ar, Kr and Xe, respectively. Noble gas concentrations measured in an artificial recharge pond were used to monitor an introduced xenon tracer and to reconstruct temperature variations to within 2 °C. Additional experiments demonstrated the capability to measure noble gases in gas and in water samples, in real time. The NG-MIMS system is capable of providing analyses sufficiently accurate and precise for introduced noble gas tracers at managed aquifer recharge facilities, groundwater fingerprinting based on excess air and noble gas recharge temperature, and field and laboratory studies investigating ebullition and diffusive exchange. Copyright © 2013 John Wiley & Sons, Ltd.

  6. The Recharging Infrastructure Needs for Long Distance Travel by Electric Vehicles: A Comparison of Battery-Switching and Quick-Charging Stations

    DEFF Research Database (Denmark)

    Christensen, Linda; Jensen, Thomas Christian; Kaplan, Sigal

    2017-01-01

    of 1–2% of the current gasoline infrastructure, under the assumption of wide availability of off-road recharging at home and the workplace; (iii) the optimal deployment of the recharging stations is along the main national highways outside of urban conurbations, under the assumption of wide...... availability of home recharging; (iv) the battery-switching technology is far more attractive to the consumer than the quick-charging technology for long-distance travel requiring more than one recharging visit....

  7. Gas separating

    Science.gov (United States)

    Gollan, A.

    1988-03-29

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  8. Is Groundwater Recharge Always Serving Us Well? Water Supply and Crop Production in Conflict in the Yahara River Watershed, Wisconsin

    Science.gov (United States)

    Booth, E.; Zipper, S. C.; Loheide, S. P.; Kucharik, C. J.

    2013-12-01

    Ecosystem service mapping is a rapidly growing field within ecology and sustainability science. Groundwater recharge is commonly treated as an ecosystem service and it can be estimated using readily available climate and soil parameters. However, groundwater recharge is only the entry-point to a complex groundwater flow system that includes both deep aquifers that municipalities tap into for water supply and shallow aquifers with water tables that can reach the ground surface. From an ecosystem service mapping perspective, groundwater recharge is almost universally treated as a beneficial service by increasing groundwater supply for municipal pumping, baseflow maintenance, and groundwater-dependent ecosystems. However, groundwater recharge can also lead to detrimental impacts such as groundwater flooding that can lead to crop losses (oxygen stress in vegetation) and property damage. While other ecosystem services that are commonly mapped provide benefits in situ (e.g. carbon sequestration), groundwater recharge belongs to a category where effects can be manifested much farther away in both space and time and can be both beneficial and detrimental to several final ecosystem services. This is the case in the Yahara River watershed, an urbanizing agricultural watershed in south-central Wisconsin. We document how groundwater recharge is treated as beneficial towards increasing municipal water supply through increasing use of infiltration practices, which are now legally required by local ordinances. We also show how an increasing precipitation trend has led to the view of groundwater recharge as detrimental towards crop production in fields where groundwater flooding and oxygen stress is evident. However, even in the same field, groundwater recharge can benefit and enhance crop production during drought conditions by decreasing water stress. These complicated and conflicting views of groundwater recharge lead to the recommendation of treating groundwater recharge as

  9. Electrodeposited oxotungstate films: Towards the molecular nature of recharging processes

    Energy Technology Data Exchange (ETDEWEB)

    Laurinavichute, Veronika K. [Moscow State University, Leninskie Gory, 1-str. 3, Moscow 119991 (Russian Federation); Vassiliev, Sergey Yu., E-mail: wasq@elch.chem.msu.r [Moscow State University, Leninskie Gory, 1-str. 3, Moscow 119991 (Russian Federation); Khokhlov, Alexander A. [Moscow State University, Leninskie Gory, 1-str. 3, Moscow 119991 (Russian Federation); Plyasova, Lyudmila M.; Molina, Irina Yu. [Boreskov Institute of Catalysis, Siberian Division of the Russian Academy of Sciences, Prosp. Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Tsirlina, Galina A. [Moscow State University, Leninskie Gory, 1-str. 3, Moscow 119991 (Russian Federation)

    2011-04-01

    In situ Raman spectroscopy is applied to supplement voltammetric, spectroelectrochemical, and XRD data on redox transformations of electrodeposited oxotungstate films. These films undergo electrochromic transition at rather positive potentials, as compared to usual sputtered tungsten oxides. The depth of electroreduction for the films conditioned in acidic solutions under open circuit is about 0.11 e{sup -} per W atom. Coloration of the films correlates with the decrease of Raman band, corresponding to the terminal W(VI)=O vibration in the hydrated phase of highly defective tungstic acid (hydrated tungsten oxide). Our data allow to state the absence of oxotungstate octahedra rearrangement in the course of reduction at positive RHE potentials, and to assume that slightly deeper reduction up to 0.15 W(V)/[W(V) + W(VI)] ratio is possible at more negative potentials. We also demonstrate that the gas phase reduction is less reversible as compared to electrochemical reduction in solution. The most possible nature of films degradation in the gas phase is their partial dehydration in the course of reduction.

  10. Legal aspects of artificial recharge of groundwater: current situation and challenges; Aspectos juridicos de la recarga artificial de acuiferos: regulacion actual y retos

    Energy Technology Data Exchange (ETDEWEB)

    Sastre Beceiro, M.

    2009-07-01

    This article examines the artificial aquifer recharge regulation in the EC and Spanish Law (State law and Andalusian law). Furthermore, it also deals with artificial aquifer recharge in Cuenca's present hydrologic plans. Next, the principal problems about artificial aquifer recharge will be described. These are: lack of a unitary regulation, lack of a homogenous definition of artificial recharge and its types, operation cost finance and at whose expense it should go, etc. We reach the conclusion that there is a need of a specific, unified and systematic regulation about artificial aquifer recharge. This regulation could comprise the following aspects: the concept for artificial aquifer recharge, types of recharge (sorted by the origin of the water and the technique that is used), recharge authorizations and conditions to be included in the title, necessary building work to recharge and its financial mechanisms (depending on its public or private condition), rights over the recharged water, supporting document for the use of the recharged water, transfer possibilities, etc. Finally, the positive effects of artificial aquifer recharges are analyzed: elevation of the piezo metric level in the aquifers that have been declared as overexploited or that are in danger of being so, wetland restoration, restraint of marine intrusion, subterranean water pollution reduction, etc. (Author) 9 refs.

  11. New low temperature electrolytes with thermal runaway inhibition for lithium-ion rechargeable batteries

    Science.gov (United States)

    Mandal, Braja K.; Padhi, Akshaya K.; Shi, Zhong; Chakraborty, Sudipto; Filler, Robert

    This paper describes a low temperature electrolyte system for lithium-ion rechargeable batteries. The electrolyte exhibits high ionic conductivity, good electrochemical stability and no exothermic reaction in the presence of lithium metal. The system features a low lattice energy lithium salt in a specific mixture of carbonate solvents and a novel thermal runaway inhibitor.

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

    Science.gov (United States)

    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.

  13. Design and Testing of Recharge Wells in a Coastal Aquifer: Summary of Field Scale Pilot Tests

    Directory of Open Access Journals (Sweden)

    Joseph Guttman

    2017-01-01

    Full Text Available Surplus water from seawater desalination plants along the Israeli Coast can be injected underground for seasonal storage. Two pilot projects were established to simulate the movement of air bubbles and changes in the well hydraulic parameters during pumping and recharging. The study showed that it is impossible to remove the smaller air bubbles (dissolved air that are created during the injection process, even when the injection pipe is fully saturated. The pumping tests showed that there were large differences in the well hydraulic parameters between the pumping and the recharge tests despite that they were conducted at the same well. Two mechanisms are responsible for the reduction in the aquifer coefficients during the recharge event. The first mechanism is the pressures that the injected water needs to overcome; the aquifer pressure and the pore water pressure it is supposed to replace at the time of the injection. The second mechanism is the pressure that the injected water needs to overcome the clogging process. It is expressed as the high water level inside the recharge well in comparison to the small rising of the water level in the observation wells. This research gives good insight into the injection mechanism through wells and is essential for any further development of injection facilities and for the operation and management protocols.

  14. ENSO diversity as a result of the equatorial recharge oscillator interacting with noise

    Science.gov (United States)

    Yu, Yanshan; Dommenget, Dietmar; Frauen, Claudia; Wales, Scott; Wang, Gang; Tyrrell, Nicholas

    2014-05-01

    In this study we address the cause of the diversity in the spatial structure of ENSO variability. We explore the idea that ENSO is a fixed pattern of variability following the recharge oscillator mechanism, which interacts with the atmospheric weather noise. We present a simulation in which a fixed pattern recharge oscillator model is coupled to an AGCM with a slab ocean model. The model is capable in simulating the leading modes of SST variability in the tropical Pacific with better agreement to the observations than most coupled GCMs in the CMIP database. The ENSO amplitude, seasonality, period, the structure of the leading pattern and its variations in an eastern and central Pacific pattern, i.e. EP El Nino and CP El Nino, are simulated very well by including the interaction of recharge oscillator and slab noise in our model. Furthermore, we find that the observed 1st EOF mode might result from the interaction between slab ocean noise and recharge oscillator which is believed to be only activated in a narrow band along the equator.

  15. Percolation pond as a method of managed aquifer recharge in a ...

    Indian Academy of Sciences (India)

    Raicy Mani Christy

    2017-07-17

    Jul 17, 2017 ... Percolation ponds have become very popular methods of managed aquifer recharge due to their low ... Australia as well as in several other parts of the world (Konikow and Kendy 2005). Climate change and large scale abstraction of groundwater for irri- ..... soil texture and spatial variation in soil moisture.

  16. Karst Aquifer in Qatar and its bearing on Natural Rainfall Recharge

    Science.gov (United States)

    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]."

  17. Characterization of LT-LiXO1-YNIYO2 electrodes for rechargeable lithium cells

    CSIR Research Space (South Africa)

    Gummow, RJ

    1993-12-01

    Full Text Available LT-LiC0.9Ni0.1O2 prepared at 400 degrees C with a structure that is intermediate between an ideal lithiated spinel and a layered structure has been investigated as an electrode in rechargeable Lithium cells; it delivers a voltage vs. pure lithium...

  18. Magmatic recharge buffers the isotopic compositions against crustal contamination in formation of continental flood basalts

    Science.gov (United States)

    Yu, Xun; Chen, Li-Hui; Zeng, Gang

    2017-07-01

    Isotopic compositions of continental flood basalts are essential to understand their genesis and to constrain the character of their mantle sources. Because of potential crustal contamination, it needs to be evaluated if and to which degree these basalts record original isotopic signals of their mantle sources and/or crustal signatures. This study examines the Sr, Nd, Hf, and Pb isotopic compositions of the late Cenozoic Xinchang-Shengzhou (XS) flood basalts, a small-scale continental flood basalt field in eastern China. The basalts show positive correlations between 87Sr/86Sr and 143Nd/144Nd, and negative correlations between 143Nd/144Nd and 176Hf/177Hf, which deviate from compositional arrays of crustal contamination and instead highlight variations in magmatic recharge intensity and mantle source compositions. The lava samples formed by high-volume magmatic recharge recorded signals of recycled sediments in the mantle source, which are characterized by moderate Ba/Th (91.9-106.5), excess 208Pb/204Pb relative to 206Pb/204Pb, and excess 176Hf/177Hf relative to 143Nd/144Nd. Thus, we propose that magmatic recharge buffers the original isotopic compositions of magmas against crustal contamination. Identifying and utilizing the isotope systematics of continental flood basalts generated by high volumes of magmatic recharge are thus crucial to trace their mantle sources.

  19. Investigation of Groundwater Flow Variations near a Recharge Pond with Repeat Deliberate Tracer Experiments

    Directory of Open Access Journals (Sweden)

    Jordan F Clark

    2014-06-01

    Full Text Available Determining hydraulic connections and travel times between recharge facilities and production wells has become increasingly important for permitting and operating managed aquifer recharge (MAR sites, a water supply strategy that transfers surface water into aquifers for storage and later extraction. This knowledge is critical for examining water quality changes and assessing the potential for future contamination. Deliberate tracer experiments are the best method for determining travel times and identifying preferential flow paths between recharge sites over the time scales of weeks to a few years. This paper compares the results of two deliberate tracer experiments at Kraemer Basin, Orange County, CA, USA. Results from the first experiment, which was conducted in October 1998, showed that a region of highly transmissive sedimentary material extends down gradient from the basin for more than 3 km [1]. Mean groundwater velocities were determined to be approximately 2 km/year in this region based on the arrival time of the tracer center of mass. A second experiment was initiated in January 2008 to determine if travel times from this basin to monitoring and production wells changed during the past decade in response to new recharge conditions. Results indicate that flow near Kraemer Basin was stable, and travel times to most wells determined during both experiments agree within the experimental uncertainty.

  20. GIS based site and structure selection model for groundwater recharge: a hydrogeomorphic approach.

    Science.gov (United States)

    Vijay, Ritesh; Sohony, R A

    2009-10-01

    The groundwater in India is facing a critical situation due to over exploitation, reduction in recharge potential by change in land use and land cover and improper planning and management. A groundwater development plan needs a large volume of multidisciplinary data from various sources. A geographic information system (GIS) based hydrogeomorphic approach can provide the appropriate platform for spatial analysis of diverse data sets for decision making in groundwater recharge. The paper presents development of GIS based model to provide more accuracy in identification and suitability analysis for finding out zones and locating suitable sites with suggested structures for artificial recharge. Satellite images were used to prepare the geomorphological and land use maps. For site selection, the items such as slope, surface infiltration, and order of drainage were generated and integrated in GIS using Weighted Index Overlay Analysis and Boolean logics. Similarly for identification of suitable structures, complex matrix was programmed based on local climatic, topographic, hydrogeologic and landuse conditions as per artificial recharge manual of Central Ground Water Board, India. The GIS based algorithm is implemented in a user-friendly way using arc macro language on Arc/Info platform.

  1. Water quality considerations on the rise as the use of managed aquifer recharge systems widens

    NARCIS (Netherlands)

    Hartog, Niels; Stuijfzand, Pieter

    2017-01-01

    Managed Aquifer Recharge (MAR) is a promising method of increasing water availability in water stressed areas by subsurface infiltration and storage, to overcome periods of drought, and to stabilize or even reverse salinization of coastal aquifers. Moreover, MAR could be a key technique in making

  2. Modeling the groundwater recharge in karst aquifers by using a reservoir model.

    Science.gov (United States)

    Ke, Tingting; Shu, Longcang; Chen, Xunhong

    2013-01-01

    The estimation of the groundwater recharge in a karstic system becomes an important challenge due to the great hydrodynamic variability in both time and space. This paper proposes a two reservoir conceptual model to simulate inflow into both the conduit system and the fissure network system based on the analysis of the spring hydrograph. The structure of the model and the governing equations are proposed on the basis of the physical considerations, with the assumption that flow at the outlet of the reservoirs obeys a linear threshold function. The model is applied on the Houzhai karstic underground river basin where it successfully reflects the temporal recharge distribution. The simulated accumulation recharge is 34.29 mm, which is reasonable in relation to the actual rainfall of 92.8 mm. The variations of water volume in two reservoirs represent the storage and transform characteristics of the karst aquifer system. However, this model is particularly well suited to simulate the recharge event after intensive rainfall.

  3. Net recharge vs. depth to groundwater relationship in the Platte River Valley of Nebraska, United States.

    Science.gov (United States)

    Szilagyi, Jozsef; Zlotnik, Vitaly A; Jozsa, Janos

    2013-01-01

    One-km resolution MODIS-based mean annual evapotranspiration (ET) estimates in combination with PRISM precipitation rates were correlated with depth to groundwater (d) values in the wide alluvial valley of the Platte River in Nebraska for obtaining a net recharge (Rn) vs. d relationship. MODIS cells with irrigation were excluded, yielding a mixture of predominantly range, pasture, grass, and riparian forest covers on sandy soils with a shallow groundwater table. The transition depth (dt ) between negative and positive values of the net groundwater recharge was found to be at about 2 (±1) m. Within 1 (±1) m of the surface and at a depth larger than about 7 to 8 (±1) m, the mean annual net recharge became independent of d at a level of about -4 (±12)% and 13 (±10)%, respectively, of the mean annual precipitation rate. The obtained Rn(d) relationship is based on a calibration-free ET estimation method and may help in obtaining the net recharge in shallow groundwater areas of negligible surface runoff where sufficient groundwater-depth data exist. © 2012, The Author(s). Groundwater © 2012, National Ground Water Association.

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

    Science.gov (United States)

    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

    2016-02-24

    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.

  5. The Laplace transform solution of a one dimensional groundwater recharge by spreading

    Directory of Open Access Journals (Sweden)

    A. P. VERMA

    1969-06-01

    Full Text Available An analytical expression for the moisture content distribution,
    in a problem of one dimensional vertical groundwater recharge, has
    been obtained by using the Laplace transform method. The average diffusivity coefficient over the whole range of moisture content is regarded as constant, and a linear variation of permeability with moisture content is assumed.

  6. Assessing the impact of modern recharge on a sandstone aquifer beneath a suburb of Doncaster, UK

    OpenAIRE

    Morris, Brian L.; Darling, W. George; Cronin, Aidan A; Rueedi, Joerg; Whitehead, Emily J.; Gooddy, Daren C.

    2006-01-01

    A major water quality issue in urban areas underlain by a productive aquifer is the impact of modern recharge. Using a variety of sample sources including multi-level boreholes, detectable concentrations of CFCs and SF6 have been found throughout the upper 50 m of the saturated aquifer beneath a suburb of Doncaster, UK, indicating that modern (

  7. 78 FR 6845 - Eleventh Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

    Science.gov (United States)

    2013-01-31

    ... Federal Aviation Administration Eleventh Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal Aviation Administration (FAA), U.S... Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY: The FAA is issuing this notice to...

  8. 78 FR 16031 - Twelfth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

    Science.gov (United States)

    2013-03-13

    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal Aviation Administration (FAA), U.S... Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY: The FAA is issuing this notice to...

  9. 77 FR 39321 - Eighth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

    Science.gov (United States)

    2012-07-02

    ... Federal Aviation Administration Eighth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Sizes AGENCY: Federal Aviation Administration (FAA), U.S... Lithium Battery and Battery Systems--Small and Medium Sizes. SUMMARY: The FAA is issuing this notice to...

  10. Percolation pond as a method of managed aquifer recharge in a ...

    Indian Academy of Sciences (India)

    This study indicated that a simple excavation without providing support for the slope and paving of the bunds helped to improve the groundwater quality. This method can be easily adoptable by farmers who can have a small pond within their farm to collect and store the rainwater. The cost of water recharged from this pond ...

  11. Transport and fate of viruses in sediment and stormwater from a managed aquifer recharge site

    Science.gov (United States)

    Enteric viruses are one of the major concerns in water reclamation and reuse at managed aquifer recharge (MAR) sites. In this study, the transport and fate of bacteriophages MS2, PRD1, and FX174 were studied in sediment and stormwater (SW) collected from a MAR site in Parafield, Australia. Column ex...

  12. Start-Up Performance of Ground-Water Recharge Trenches Rocky Mountain Arsenal

    Science.gov (United States)

    1989-08-01

    trench system as an interim remedial action. The NBT was previ- ously deficient in its recharge functions, especially west of D Street, because of the...Phillips Supac 4 NP,* a 4-oz/yd 2 nonwoven polyester. Two observational piezometers were placed in each trench (Figure 2) and ten others were located

  13. The effect of alkaline earth titanates on the rechargeability of manganese dioxide in alkaline electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Kloss, M.; Rahner, D.; Plieth, W. [Dresden Univ. of Technology, Inst. of Physical Chemistry and Electrochemistry, Dresden (Germany)

    1997-11-01

    Various alkaline earth titanates were tested as the additives for manganese dioxide electrodes in aqueous electrolyte (9 mol/1 KOH) at room temperature. The influence of the additives on the discharge capacity of primary cells and especially on cycling behaviour of rechargeable alkaline batteries is discussed. (orig.)

  14. Early findings from artificial recharge efforts of the Mississippi River Valley Alluvial Aquifer

    Science.gov (United States)

    The long-term success and sustainability of agriculture in the Lower Mississippi River Basin will depend largely on water resources. Aquifer decline in the region has been documented since the 1980s and continues today. Artificial recharge is one possible tool that could help alleviate this declin...

  15. Response to recharge variation of thin rainwater lenses and their mixing zone with underlying saline groundwater

    NARCIS (Netherlands)

    Eeman, S.; Zee, van der S.E.A.T.M.; Leijnse, A.; Louw, de P.G.B.; Maas, C.

    2012-01-01

    In coastal zones with saline groundwater, fresh groundwater lenses may form due to infiltration of rain water. The thickness of both the lens and the mixing zone, determines fresh water availability for plant growth. Due to recharge variation, the thickness of the lens and the mixing zone are not

  16. Monitoring infiltration and recharge of playa lakes in the Texas Southern High Plains

    Science.gov (United States)

    Preliminary results from playa lakes monitored by the Texas Water Development Board (TWDB) suggest that a small volume of deep infiltration and recharge to the Ogallala aquifer occurs along the margins of the lake beds, while the majority of infiltration associated with a typical inundation remains ...

  17. Estimation of recharge using a revised CRD method | Xu | Water SA

    African Journals Online (AJOL)

    The cumulative rainfall departure (CRD) method, based on the water-balance principle, is often used for mimicking of water level fluctuations. Because of its simplicity and minimal requirement of spatial data, the CRD method has been applied widely for estimating either effective recharge or aquifer storativity, and ...

  18. Recharge mixing in a complex distributary spring system in the Missouri Ozarks, USA

    Science.gov (United States)

    Toronto Springs is a complex distributary karst spring system with 11 perennial springs in the central Missouri Ozarks, USA. Carroll Cave (CC) and Wet Glaize Creek (WG) were previously identified as principal recharge sources. This study 1) characterized physical and chemical properties of the sprin...

  19. Random number datasets generated from statistical analysis of randomly sampled GSM recharge cards.

    Science.gov (United States)

    Okagbue, Hilary I; Opanuga, Abiodun A; Oguntunde, Pelumi E; Ugwoke, Paulinus O

    2017-02-01

    In this article, a random number of datasets was generated from random samples of used GSM (Global Systems for Mobile Communications) recharge cards. Statistical analyses were performed to refine the raw data to random number datasets arranged in table. A detailed description of the method and relevant tests of randomness were also discussed.

  20. Managed aquifer recharge through off-season irrigation in agricultural regions

    Science.gov (United States)

    Niswonger, Richard; Morway, Eric; 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.

  1. Estimating daily recharge to the Chalk aquifer of southern England – a simple methodology

    Directory of Open Access Journals (Sweden)

    K. J. Limbrick

    2002-01-01

    Full Text Available A simple, practical model for estimating daily recharge - as hydrologically effective rainfall (HER - to the Chalk outcrop of southern England is presented. Daily meteorological observations are the only data requirements. The model was calibrated for a Chalk river, the Wey, in south Dorset. Six different root constant thresholds were used to estimate daily actual evapotranspiration (AET rates for the river. The model was then used to calculate HER using the six estimates of AET. Daily mean flow was simulated using three different models: CAPTAIN, IHACRES and INCA. The six HER estimates provided independent model inputs. HER calculated using a root constant of 200mm proved suitable not only for the Wey, but also (via a validation exercise for other rivers on the Chalk of southern England for riverflow simulations as well as the timing and magnitude of groundwater recharge. The results suggest that a root constant of 200mm is optimal for the Chalk outcrop of southern England. The model is particularly useful for studies where the application of more complex methods of recharge estimation is impractical. Keywords: Chalk aquifer, root constant, recharge, Hydrologically Effective Rainfall, model, riverflow, CAPTAIN, IHACRES, INCA, River Wey

  2. Graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes

    Science.gov (United States)

    Liu, Jun; Lemmon, John P; Yang, Zhenguo; Cao, Yuiliang; Li, Xiaolin

    2014-06-17

    Rechargeable lithium-sulfur batteries having a cathode that includes a graphene-sulfur nanocomposite can exhibit improved characteristics. The graphene-sulfur nanocomposite can be characterized by graphene sheets with particles of sulfur adsorbed to the graphene sheets. The sulfur particles have an average diameter less than 50 nm..

  3. Estimation of ground water recharge using SWAP model for an alpine area in Austria

    Science.gov (United States)

    Mohamed, Rasha; Klik, Andreas; Kammerer, Gerhard; Fuchs, Gabriele

    2010-05-01

    Groundwater is an important resource for drinking water in Austria and therefore quantity and quality need to be protected. Objective of this study was to assess ground water recharge rates for a forested site located in in the North Tyrolean limestone Alps in Achenkirch, Austria. In 1997 the Hydrographic Survey in Austria started a soil water monitoring station equipped with FDR-sensors to measure soil water content and with tensiometers for matric potential measurement in four depths (5 cm, 15 cm, 25 cm and 50 cm). Data was collected in 4 hour intervals. Additionally runoff plots were installed to collect surface runoff during the study period. SWAP model was used to predict ground water recharge using climatic data (1997-2007) and measured data. The necessary soil input parameters were derived from field measured data using pedotransfer functions and additional investigations of soil hydraulic parameters in the field. The total ground water recharge during the study period ranged from 527 mm in year 2003 to 1126 mm in year 1999 with an annually average of 765 mm. SWAP model showed a good fit between the measured and the simulated soil water contents as well as interception data. Less fit was obtained for soil water tension results during some years. This study will continue to improve parameters to simulate soil tension and also to estimate the ground water recharge using other models.

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

    Science.gov (United States)

    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 ...

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

    Science.gov (United States)

    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

  6. Recharge Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    MJ Fayer; EM Murphy; JL Downs; FO Khan; CW Lindenmeier; BN Bjornstad

    2000-01-18

    Lockheed Martin Hanford Company (LMHC) is designing and assessing the performance of disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site. The preferred method of disposing of the portion that is classified as immobilized low-activity waste (ILAW) is to vitrify the waste and place the product in near-surface, shallow-land burial facilities. The LMHC project to assess the performance of these disposal facilities is known as the Hanford ILAW Performance Assessment (PA) Activity, hereafter called the ILAW PA project. The goal of this project is to provide a reasonable expectation that the disposal of the waste is protective of the general public, groundwater resources, air resources, surface-water resources, and inadvertent intruders. Achieving this goal will require predictions of contaminant migration from the facility. To make such predictions will require estimates of the fluxes of water moving through the sediments within the vadose zone around and beneath the disposal facility. These fluxes, loosely called recharge rates, are the primary mechanism for transporting contaminants to the groundwater. Pacific Northwest National Laboratory (PNNL) assists LMHC in their performance assessment activities. One of the PNNL tasks is to provide estimates of recharge rates for current conditions and long-term scenarios involving the shallow-land disposal of ILAW. Specifically, recharge estimates are needed for a filly functional surface cover; the cover sideslope, and the immediately surrounding terrain. In addition, recharge estimates are needed for degraded cover conditions. The temporal scope of the analysis is 10,000 years, but could be longer if some contaminant peaks occur after 10,000 years. The elements of this report compose the Recharge Data Package, which provides estimates of recharge rates for the scenarios being considered in the 2001 PA. Table S.1 identifies the surface features and

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

    Science.gov (United States)

    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 (precharge ability of the three

  8. Multivariate indications between environment and ground water recharge in a sedimentary drainage basin in northwestern China

    Science.gov (United States)

    Zhu, Bingqi; Wang, Xunming; Rioual, Patrick

    2017-06-01

    A paucity of studies on the interaction between environment and ground water recharge severely restricts the ability of people to assess future water resources under changing environment. In this study, an effort to explore the relationship between the arid environment and ground water recharge was carried out using multivariate statistical techniques in a sedimentary drainage basin (the Jungar) in northwestern China. Hierarchical cluster analysis (HCA) and principal components analysis (PCA) were performed based on hydrogeochemical data to assess the ground water recharge and its governing factors. Observation of the HCA and PCA analytical results revealed a division of seven clusters (C1 to C7) and three principal components (PC1 to PC3), which explained 59.6%, 16.6% and 10.9% of the variance, respectively, and thus, accounted for the majority of the total variance in the original dataset. Based on these Q-mode HCA clusters and R-mode PAC scores, dominant environmental processes influencing recharge regimes were identified, i.e., geogenic, geomorphoclimatic, and anthropogenic, which separated the recharge regimes into four zones (Zone I to Zone IV). Zones I and II (C4 + C1) were associated to "elevated hydroclimate degree" coupled to "low salinity". Zone III (C2 + C3) was associated to "moderately elevated salinity" and evidently "elevated contamination" but coupled to "low hydroclimate degree". Zone IV (C5 + C6 + C7) was associated mainly to "elevated salinity" coupled to "low or inverse hydroclimate degree". It revealed that the geogenic processes are more significant (60%) than the geomorphoclimatic (17%) and anthropogenic (11%) processes. As a result, the overall recharge process is rather heterogeneous and is strongly environment dominated in the Jungar drainage system. Compared with other watersheds in arid environment, a distinctive feature of the Jungar waters is that they are affected by a combination of natural and non-natural events, rather than

  9. Mitigating agricultural impacts on groundwater using distributed managed aquifer recharge ponds

    Science.gov (United States)

    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

  10. Artificial groundwater recharge as integral part of a water resources system in a humid environment

    Science.gov (United States)

    Kupfersberger, Hans; Stadler, Hermann

    2010-05-01

    In Graz, Austria, artificial groundwater recharge has been operated as an integral part of the drinking water supply system for more than thirty years. About 180 l/s of high quality water from pristine creeks (i.e. no pre-treatment necessary) are infiltrated via sand and lawn basins and infiltration trenches into two phreatic aquifers to sustain the extraction of approximately 400 l/s. The remaining third of drinking water for roughly 300.000 people is provided by a remote supply line from the East alpine karst region Hochschwab. By this threefold model the water supply system is less vulnerable to external conditions. In the early 1980's the infiltration devices were also designed as a hydraulic barrier against riverbank infiltration from the river Mur, which at that time showed seriously impaired water quality due to upstream paper mills. This resulted into high iron and manganese groundwater concentrations which lead to clogging of the pumping wells. These problems have been eliminated in the meantime due to the onsite purification of paper mill effluents and the construction of many waste water treatment plants. The recharge system has recently been thoroughly examined to optimize the operation of groundwater recharge and to provide a basis for further extension. The investigations included (i) field experiments and laboratory analyses to improve the trade off between infiltration rate and elimination capacities of the sand filter basins' top layer, (ii) numerical groundwater modelling to compute the recovery rate of the recharged water, the composition of the origin of the pumped water, emergency scenarios due to the failure of system parts, the transient capture zones of the withdrawal wells and the coordination of recharge and withdrawal and (iii) development of an online monitoring setup combined with a decision support system to guarantee reliable functioning of the entire structure. Additionally, the depreciation, maintenance and operation costs of the

  11. Modelling the effects of climate and land cover change on groundwater recharge in south-west Western Australia

    Directory of Open Access Journals (Sweden)

    W. Dawes

    2012-08-01

    Full Text Available The groundwater resource contained within the sandy aquifers of the Swan Coastal Plain, south-west Western Australia, provides approximately 60 percent of the drinking water for the metropolitan population of Perth. Rainfall decline over the past three decades coupled with increasing water demand from a growing population has resulted in falling dam storage and groundwater levels. Projected future changes in climate across south-west Western Australia consistently show a decline in annual rainfall of between 5 and 15 percent. There is expected to be a reduction of diffuse recharge across the Swan Coastal Plain. This study aims to quantify the change in groundwater recharge in response to a range of future climate and land cover patterns across south-west Western Australia.

    Modelling the impact on the groundwater resource of potential climate change was achieved with a dynamically linked unsaturated/saturated groundwater model. A vertical flux manager was used in the unsaturated zone to estimate groundwater recharge using a variety of simple and complex models based on climate, land cover type (e.g. native trees, plantation, cropping, urban, wetland, soil type, and taking into account the groundwater depth.

    In the area centred on the city of Perth, Western Australia, the patterns of recharge change and groundwater level change are not consistent spatially, or consistently downward. In areas with land-use change, recharge rates have increased. Where rainfall has declined sufficiently, recharge rates are decreasing, and where compensating factors combine, there is little change to recharge. In the southwestern part of the study area, the patterns of groundwater recharge are dictated primarily by soil, geology and land cover. In the sand-dominated areas, there is little response to future climate change, because groundwater levels are shallow and much rainfall is rejected recharge. Where the combination of native vegetation and

  12. Use of apparent water age at groundwater production wells to evaluate maps of long term average groundwater recharge

    Science.gov (United States)

    Selle, B.; Shakked, N.; Rink, K.; Kolditz, O.

    2012-04-01

    The long-term average groundwater recharge typically varies greatly in space due to differences in climate, soil, landuse, topography and groundwater levels. Long-term average recharge is a key input to steady- state groundwater models. This type of models is frequently used to determine the long-term safe yield to aquifer systems and to predict the fate of human-derived contaminants in capture zones of groundwater production wells. An accurate quantification of the spatial distribution of recharge is therefore important but difficult to achieve as it cannot be directly measured at regional scales. Several methods have been applied to indirectly estimate the spatial distribution of long-term average groundwater recharge including spatially distributed hydrological modelling and the regionalisation of catchment scale recharge estimated from long-term average baseflows. In the context of a groundwater model, it is difficult to evaluate the reliability of these recharge maps if groundwater levels are the only data set available for model calibration. Concentrations of environmental tracers measured at groundwater wells can be used to interpret the apparent groundwater age, which in turn is significantly influenced by the magnitude and spatial distribution of recharge contributing groundwater to the well. Thus, the apparent groundwater age at wells may be useful to assess the reliability of maps on long term average groundwater recharge. To test this hypothesis, a steady-state groundwater model was set up for a 180 km2 area in SW Germany, which is extensively used for groundwater production from a confined limestone aquifer. We tested three maps of long-term average recharge that were all computed using different methods. For each recharge map, the steady-state groundwater model was calibrated against water levels and mean groundwater ages were calculated for groundwater production wells from particle tracking methods. These computed groundwater ages were subsequently

  13. Modelling the effects of climate and land cover change on groundwater recharge in south-west Western Australia

    Science.gov (United States)

    Dawes, W.; Ali, R.; Varma, S.; Emelyanova, I.; Hodgson, G.; McFarlane, D.

    2012-08-01

    The groundwater resource contained within the sandy aquifers of the Swan Coastal Plain, south-west Western Australia, provides approximately 60 percent of the drinking water for the metropolitan population of Perth. Rainfall decline over the past three decades coupled with increasing water demand from a growing population has resulted in falling dam storage and groundwater levels. Projected future changes in climate across south-west Western Australia consistently show a decline in annual rainfall of between 5 and 15 percent. There is expected to be a reduction of diffuse recharge across the Swan Coastal Plain. This study aims to quantify the change in groundwater recharge in response to a range of future climate and land cover patterns across south-west Western Australia. Modelling the impact on the groundwater resource of potential climate change was achieved with a dynamically linked unsaturated/saturated groundwater model. A vertical flux manager was used in the unsaturated zone to estimate groundwater recharge using a variety of simple and complex models based on climate, land cover type (e.g. native trees, plantation, cropping, urban, wetland), soil type, and taking into account the groundwater depth. In the area centred on the city of Perth, Western Australia, the patterns of recharge change and groundwater level change are not consistent spatially, or consistently downward. In areas with land-use change, recharge rates have increased. Where rainfall has declined sufficiently, recharge rates are decreasing, and where compensating factors combine, there is little change to recharge. In the southwestern part of the study area, the patterns of groundwater recharge are dictated primarily by soil, geology and land cover. In the sand-dominated areas, there is little response to future climate change, because groundwater levels are shallow and much rainfall is rejected recharge. Where the combination of native vegetation and clayey surface soils restricts possible

  14. 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)

    Science.gov (United States)

    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

  15. Landfill gas

    Energy Technology Data Exchange (ETDEWEB)

    Hartnell, Gaynor [Landfill Gas Association (United Kingdom)

    2000-07-01

    Following the UK Government's initiative for stimulating renewable energy through the Non-Fossil Fuel Obligation (NFFO), the UK landfill gas industry has more than trebled in size in just 4 years. As a result, UK companies are now in a strong position to offer their skills and services overseas. Ireland, Greece and Spain also resort heavily to disposal to landfill. Particularly rapid growth of the landfill gas market is expected in the OECD-Pacific and NAFTA areas. The article explains that landfill gas is a methane-rich mixture produced by anaerobic decomposition of organic wastes in landfills: under optimum conditions, up to 500 cubic meters of gas can be obtained from 1 tonne of biodegradable waste. Data on the number and capacity of sites in the UK are given. The Landfill Gas Association runs courses to counteract the skills shortage in the UK, and tailored courses for overseas visitors are planned.

  16. Characterizing Sources of Recharge and Groundwater Quality in Sacramento Aquifers Following California's Historic Drought

    Science.gov (United States)

    Robertson, C. A.; Paukert Vankeuren, A. N.; Wagner, A. J.; Blackburn, C.; Druecker, D.

    2016-12-01

    Characterizing recharge will be critical for sustainable groundwater use, particularly following California's historic five-year drought . Groundwater is of great importance to Sacramento, which is a high priority basin as determined by the Sustainable Groundwater Management Act of 2014. The California State University, Sacramento (CSUS) campus has 18 monitoring wells, making it an ideal laboratory for examination of recharge sources and water quality in confined and unconfined aquifers in the Central Valley aquifer system. Historically, CSUS aquifers appear to have been recharged by water from the Western Sierra Nevada. The campus is bounded by the Lower American River, and some of its wells are in hydraulic connection with the river1. Lower than average river stage during the drought may have affected recharge to the aquifers from the river. Additionally, low impact development (LID) stormwater-management ponds have recently been installed on campus in an effort to increase infiltration and to help mitigate contamination of the aquifers and American River from campus runoff. The recently installed LID ponds on campus may have increased infiltration of local precipitation into the unconfined aquifer. Data collected from the monitoring wells allow for the examination of differences between the confined and unconfined aquifer systems in the Central Valley. To identify recharge sources, stable isotope and major ion analyses for samples collected from both campus aquifers are compared to samples from local precipitation and rivers in the Western Sierra Nevada feeding the American River. These results are used to assess current water quality and compared to historic datasets collected by the USGS to reveal changes that have occurred as a result of the recent drought. These data are the first in a dataset developed by CSUS Geology students for long-term monitoring of local groundwater quality. 1Moran et al., 2004. LLNL, UCR-203258.

  17. Occurrences and regional distributions of 20 antibiotics in water bodies during groundwater recharge.

    Science.gov (United States)

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

    2015-06-15

    To develop a better understanding of the pollution conditions of antibiotics during the groundwater recharge process, a nation-wide survey was conducted across China for the first time. Overall, 15 recharge sites employing reclaimed water located in different humid, semi-humid and semi-arid regions were selected for analysis of the presence of the 20 most commonly used antibiotics, including tetracyclines (TCs), fluoroquinolones (FQNs), sulfonamides (SAs) and macrolides. All types of antibiotics were detected at concentrations of 212-4035 ng/L in reclaimed water and 19-1270 ng/L in groundwater. FQNs were the predominant antibiotics in reclaimed water samples (38%), followed by SAs (34%). In the SAs group, sulfamethoxazole (SMZ) and sulfamonomethoxine together with trimethoprim accounted for 78% of the total, while ofloxacin (OFL) and norfloxacin accounted for 90% of the FQNs, and doxycycline and oxytetracycline accounted for 82% of the TCs. The concentrations in groundwater were generally 1-2 orders of magnitude lower than in reclaimed water. The three most common antibiotics were OFL, erythromycin (ERY) and SMZ. Similar occurrences of different group antibiotics might be evidence of the influence of groundwater recharge by reclaimed water. FQNs were predominant in northern China, while SAs were predominant in the south. Ecotoxicological risk assessment showed that SMZ, ERY and OFL had the top three hazard quotient values, indicating they should receive preferential treatment before recharging. Overall, these results provide a theoretical basis for development of a recharge standard in China. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Assessing effects of native forest restoration on soil moisture dynamics and potential aquifer recharge, Auwahi, Maui

    Science.gov (United States)

    Perkins, Kim S.; Nimmo, John R.; Medeiros, Arthur C.; Szutu, Daphne J.; von Allmen, Erica

    2014-01-01

    Understanding the role of soils in regulating water flow through the unsaturated zone is critical in assessing the influence of vegetation on soil moisture dynamics and aquifer recharge. Because of fire, introduced ungulates and landscape-level invasion of non-native grasses, less than 10% of original dry forest (~730 mm precipitation annually) still exists on leeward Haleakalā, Maui, Hawaiian Islands. Native dry forest restoration at Auwahi has demonstrated the potential for dramatic revegetation, allowing a unique experimental comparison of hydrologic function between tracts of restored forest and adjacent grasslands. We hypothesized that even relatively recent forest restoration can assist in the recovery of impaired hydrologic function, potentially increasing aquifer recharge. To compare restored forest and grassland sites, we experimentally irrigated and measured soil moisture and temperature with subsurface instrumentation at four locations within the reforested area and four within the grassland, each with a 2·5 × 2·5-m plot. Compared with grassland areas, water in reforested sites moved to depth faster with larger magnitude changes in water content. The median first arrival velocity of water was greater by a factor of about 13 in the reforested sites compared with the grassland sites. This rapid transport of water to depths of 1 m or greater suggests increased potential aquifer recharge. Improved characterization of how vegetation and soils influence recharge is crucial for understanding the long-term impacts of forest restoration on aquifer recharge and water resources, especially in moisture-limited regions.

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

    Science.gov (United States)

    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.

  20. Performance evaluation of a reverse-gradient artificial recharge system in basalt aquifers of Maharashtra, India

    Science.gov (United States)

    Bhusari, Vijay; Katpatal, Y. B.; Kundal, Pradeep

    2017-05-01

    Drinking water scarcity in rural parts of central India in basaltic terrain is common. Most of the rural population depends on groundwater sources located in the fractured and weathered zone of the basaltic aquifers. Long-term indiscriminate withdrawal has caused an alarming rate of depletion of groundwater levels in both pre- and post-monsoon periods. The aquifer is not replenished through precipitation under natural conditions. To overcome this situation, an innovative artificial recharge system, called the reverse-gradient recharge system (RGRS), was implemented in seven villages of Wardha district of Maharashtra. The study described here presents a comparative analysis of recharge systems constructed in the year 2012 downstream of dug-well locations in these seven villages. The post-project comparative analysis reveals that the area of influence (AOI) of the groundwater recharge system, within which increases in groundwater levels and yield are observed, is directly related to the specific yield, thickness of the weathered and fractured zone, porosity, and transmissivity of the aquifer, showing high correlation coefficients of 0.92, 0.88, 0.85 and 0.83, respectively. The study indicates that the RGRS is most effective in vesicular weathered and fractured basalt, recording a maximum increase in well yield of 65-82 m3/day, while a minimum increase in yield of 15-30 m3/day was observed in weathered vesicular basalt. The comparative analysis thus identifies the controlling factors which facilitate groundwater recharge through the proposed RGRS. After implementation of these projects, the groundwater availability in these villages increased significantly, solving their drinking water problems.

  1. Is annual recharge coefficient a valid concept in arid and semi-arid regions?

    Science.gov (United States)

    Cheng, Yiben; Zhan, Hongbin; Yang, Wenbin; Dang, Hongzhong; Li, Wei

    2017-10-01

    Deep soil recharge (DSR) (at depth greater than 200 cm) is an important part of water circulation in arid and semi-arid regions. Quantitative monitoring of DSR is of great importance to assess water resources and to study water balance in arid and semi-arid regions. This study used a typical bare land on the eastern margin of Mu Us Sandy Land in the Ordos Basin of China as an example to illustrate a new lysimeter method of measuring DSR to examine if the annual recharge coefficient is valid or not in the study site, where the annual recharge efficient is the ratio of annual DSR over annual total precipitation. Positioning monitoring was done on precipitation and DSR measurements underneath mobile sand dunes from 2013 to 2015 in the study area. Results showed that use of an annual recharge coefficient for estimating DSR in bare sand land in arid and semi-arid regions is questionable and could lead to considerable errors. It appeared that DSR in those regions was influenced by precipitation pattern and was closely correlated with spontaneous strong precipitation events (with precipitation greater than 10 mm) other than the total precipitation. This study showed that as much as 42 % of precipitation in a single strong precipitation event can be transformed into DSR. During the observation period, the maximum annual DSR could make up 24.33 % of the annual precipitation. This study provided a reliable method of estimating DSR in sandy areas of arid and semi-arid regions, which is valuable for managing groundwater resources and ecological restoration in those regions. It also provided strong evidence that the annual recharge coefficient was invalid for calculating DSR in arid and semi-arid regions. This study shows that DSR is closely related to the strong precipitation events, rather than to the average annual precipitation, as well as the precipitation patterns.

  2. Spatial and temporal variability of groundwater recharge in Geba basin, Northern Ethiopia

    Science.gov (United States)

    Yenehun, Alemu; Walraevens, Kristine; Batelaan, Okke

    2017-10-01

    WetSpa, a physically based, spatially distributed watershed model, has been used to study the spatial and temporal variation of recharge in the Geba basin, Northern Ethiopia. The model covers an area of about 4, 249 km2 and integrates elevation, soil and land-use data, hydrometeorological and river discharge data. The Geba basin has a highly variable topography ranging from 1000 to 3280 m with an average slope of 12.9%. The area is characterized by a distinct wet and long dry season with a mean annual precipitation of 681 mm and temperatures ranging between 6.5 °C and 32 °C. The model was simulated on daily basis for nearly four years (January 1, 2000 to December 18, 2003). It resulted in a good agreement between measured and simulated streamflow hydrographs with Nash-Sutcliffe efficiency of almost 70% and 85% for, respectively, the calibration and validation. The water balance terms show very strong spatial and temporal variability, about 3.8% of the total precipitation is intercepted by the plant canopy; 87.5% infiltrates into the soil (of which 13% percolates, 2.7% flows laterally off and 84.2% evapotranspired from the root zone), and 7.2% is surface runoff. The mean annual recharge varies from about 45 mm (2003) to 208 mm (2001), with average of 98.6 mm/yr. On monthly basis, August has the maximum (73 mm) and December the lowest (0.1 mm) recharge. The mean annual groundwater recharge spatially varies from 0 to 371 mm; mainly controlled by the distribution of rainfall amount, followed by soil and land-use, and to a certain extent, slope. About 21% of Geba has a recharge larger than 120 mm and 1% less than 5 mm.

  3. Inverse modeling and uncertainty analysis of potential groundwater recharge to the confined semi-fossil Ohangwena II Aquifer, Namibia

    Science.gov (United States)

    Wallner, Markus; Houben, Georg; Lohe, Christoph; Quinger, Martin; Himmelsbach, Thomas

    2017-12-01

    The identification of potential recharge areas and estimation of recharge rates to the confined semi-fossil Ohangwena II Aquifer (KOH-2) is crucial for its future sustainable use. The KOH-2 is located within the endorheic transboundary Cuvelai-Etosha-Basin (CEB), shared by Angola and Namibia. The main objective was the development of a strategy to tackle the problem of data scarcity, which is a well-known problem in semi-arid regions. In a first step, conceptual geological cross sections were created to illustrate the possible geological setting of the system. Furthermore, groundwater travel times were estimated by simple hydraulic calculations. A two-dimensional numerical groundwater model was set up to analyze flow patterns and potential recharge zones. The model was optimized against local observations of hydraulic heads and groundwater age. The sensitivity of the model against different boundary conditions and internal structures was tested. Parameter uncertainty and recharge rates were estimated. Results indicate that groundwater recharge to the KOH-2 mainly occurs from the Angolan Highlands in the northeastern part of the CEB. The sensitivity of the groundwater model to different internal structures is relatively small in comparison to changing boundary conditions in the form of influent or effluent streams. Uncertainty analysis underlined previous results, indicating groundwater recharge originating from the Angolan Highlands. The estimated recharge rates are less than 1% of mean yearly precipitation, which are reasonable for semi-arid regions.

  4. Inverse modeling and uncertainty analysis of potential groundwater recharge to the confined semi-fossil Ohangwena II Aquifer, Namibia

    Science.gov (United States)

    Wallner, Markus; Houben, Georg; Lohe, Christoph; Quinger, Martin; Himmelsbach, Thomas

    2017-07-01

    The identification of potential recharge areas and estimation of recharge rates to the confined semi-fossil Ohangwena II Aquifer (KOH-2) is crucial for its future sustainable use. The KOH-2 is located within the endorheic transboundary Cuvelai-Etosha-Basin (CEB), shared by Angola and Namibia. The main objective was the development of a strategy to tackle the problem of data scarcity, which is a well-known problem in semi-arid regions. In a first step, conceptual geological cross sections were created to illustrate the possible geological setting of the system. Furthermore, groundwater travel times were estimated by simple hydraulic calculations. A two-dimensional numerical groundwater model was set up to analyze flow patterns and potential recharge zones. The model was optimized against local observations of hydraulic heads and groundwater age. The sensitivity of the model against different boundary conditions and internal structures was tested. Parameter uncertainty and recharge rates were estimated. Results indicate that groundwater recharge to the KOH-2 mainly occurs from the Angolan Highlands in the northeastern part of the CEB. The sensitivity of the groundwater model to different internal structures is relatively small in comparison to changing boundary conditions in the form of influent or effluent streams. Uncertainty analysis underlined previous results, indicating groundwater recharge originating from the Angolan Highlands. The estimated recharge rates are less than 1% of mean yearly precipitation, which are reasonable for semi-arid regions.

  5. Forecasting the settlement of a bioreactor landfill based on gas pressure changes.

    Science.gov (United States)

    Qiu, Gang; Li, Liang; Sun, Hongjun

    2013-10-01

    In order to study the influence of settlement under gas pressure in bioreactor landfill, the landfill is simplified as a one-way gas seepage field, combining Darcy's Law, the gas equation of state, and the principle of effective stress and fluid dynamics of porous media theory. First assume that the bioreactor landfill leachate is fully recharged on the basis of gas mass conservation, then according to the changes in gas pressure (inside the landfill and surrounding atmosphere) during the gas leakage time and settlement in the landfill, establish a numerical model of bioreactor landfill settlement under the action of the gas pressure, and use the finite difference method to solve it. Through a case study, the model's improved prediction of the settlement of bioreactor landfill is demonstrated.

  6. Evaluation of changes in post-fire recharge under native woodland using hydrological measurements, modelling and remote sensing

    Science.gov (United States)

    Silberstein, Richard P.; Dawes, Warrick R.; Bastow, Trevor P.; Byrne, John; Smart, Natalie F.

    2013-05-01

    SummaryThis paper examines the use of a controlled fuel reduction burn in native woodland to increase recharge to a shallow aquifer system for water supply in south-western Australia. Soil moisture trends from neutron probe measurements and watertable dynamics from piezometers under adjacent burned and unburned plots were compared to determine the difference in recharge resulting from the fire. Remotely sensed evapotranspiration (ET) subtracted from rainfall was used to independently estimate groundwater and soil moisture recharge and compare against a physically based model of soil-water fluxes. The use of naturally occurring chemicals (n-alkanes and cycloalkanes) produced in the fire as tracers of the recharge pulse in the winter following the fire was tested. It was found that in the winter following the fire (annual rainfall 701 mm), water storage in the 9 m thick unsaturated zone increased by about 300 mm but recharge to the watertable was only about 60 mm. In the subsequent year (rainfall 630 mm), leaf area index in the burned woodland recovered to be about 10% less than the unburned plot, remotely sensed ET rose above that in the unburned plot and recharge was lower in the burned than unburned plot. This trend continued and, after 3 years, increased ET negated any early recharge gains, and there was a net decrease in recharge resulting from the fire. The combination of water balance measurements, modelling and remote sensing provides a robust method to gain hydrological understanding of recharge mechanisms. Further work is required to refine the use of burn residue chemicals as soil water tracers, particularly in improving instrument design for groundwater sample collection in fine textured soils. As climate continues to change and regions with growing water shortages seek innovative solutions, approaches such as controlled burning may be needed; however, in this example, the approach was unproductive and further the environmental consequences need to be

  7. Water quality of the Little Arkansas River and Equus Beds Aquifer before and concurrent with large-scale artificial recharge, south-central Kansas, 1995-2012

    Science.gov (United States)

    Tappa, Daniel J.; Lanning-Rush, Jennifer L.; Klager, Brian J.; Hansen, Cristi V.; Ziegler, Andrew C.

    2015-01-01

    The city of Wichita artificially recharged about 1 billion gallons of water into the Equus Beds aquifer during 2007–2012 as part of Phase I recharge of the Artificial Storage and Recovery project. This report, prepared in cooperation by the U.S. Geological Survey and the city of Wichita, Kansas, summarizes Little Arkansas River (source-water for artificial recharge) andEquus Beds aquifer water quality before (1995–2006) and during (2007–2012) Artificial Storage and Recovery Phase I recharge. Additionally, aquifer water-quality distribution maps are presented and water-quality changes associated with Phase I recharge timing are described.

  8. Gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Farahan, E.; Eudaly, J.P.

    1978-10-01

    This evaluation provides performance and cost data for commercially available simple- and regenerative-cycle gas turbines. Intercooled, reheat, and compound cycles are discussed from theoretical basis only, because actual units are not currently available, except on a special-order basis. Performance characteristics investigated include unit efficiency at full-load and off-design conditions, and at rated capacity. Costs are tabulated for both simple- and regenerative-cycle gas turbines. The output capacity of the gas turbines investigated ranges from 80 to 134,000 hp for simple units and from 12,000 to 50,000 hp for regenerative units.

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

    Science.gov (United States)

    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

  10. Quantity and location of groundwater recharge in the Sacramento Mountains, south-central New Mexico (USA), and their relation to the adjacent Roswell Artesian Basin

    Science.gov (United States)

    Rawling, Geoffrey C.; Newton, B. Talon

    2016-06-01

    The Sacramento Mountains and the adjacent Roswell Artesian Basin, in south-central New Mexico (USA), comprise a regional hydrologic system, wherein recharge in the mountains ultimately supplies water to the confined basin aquifer. Geologic, hydrologic, geochemical, and climatologic data were used to delineate the area of recharge in the southern Sacramento Mountains. The water-table fluctuation and chloride mass-balance methods were used to quantify recharge over a range of spatial and temporal scales. Extrapolation of the quantitative recharge estimates to the entire Sacramento Mountains region allowed comparison with previous recharge estimates for the northern Sacramento Mountains and the Roswell Artesian Basin. Recharge in the Sacramento Mountains is estimated to range from 159.86 × 106 to 209.42 × 106 m3/year. Both the location of recharge and range in estimates is consistent with previous work that suggests that ~75 % of the recharge to the confined aquifer in the Roswell Artesian Basin has moved downgradient through the Yeso Formation from distal recharge areas in the Sacramento Mountains. A smaller recharge component is derived from infiltration of streamflow beneath the major drainages that cross the Pecos Slope, but in the southern Sacramento Mountains much of this water is ultimately derived from spring discharge. Direct recharge across the Pecos Slope between the mountains and the confined basin aquifer is much smaller than either of the other two components.

  11. Geochemical processes in a calcareous sandstone aquifer during managed aquifer recharge with desalinated seawater

    Science.gov (United States)

    Ganot, Yonatan; Russak, Amos; Siebner, Hagar; Bernstein, Anat; Katz, Yoram; Guttman, Jospeh; Kurtzman, Daniel

    2017-04-01

    In the last three years we monitor Managed Aquifer Recharge (MAR) of post-treated desalinated seawater (PTDES) in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. The PTDES are stabilized with CaCO3 during post-treatment in the desalination plant and their chemical composition differs from those of any other water recharged to the aquifer and of the natural groundwater. We use suction cups in the unsaturated zone, shallow observation wells within the pond and production wells that encircles the MAR Menashe site, to study the geochemical processes during MAR with PTDES. Ion-enrichment (remineralization) of the recharged water was observed in both unsaturated zone and shallow observation wells samples. Enrichment occurs mainly in the first few meters below the pond surface by ion-exchange processes. Mg2+ enrichment is most prominent due to its deficiency in the PTDES. It is explained by ion-exchange with Ca2+, as the PTDES (enriched with Ca2+) infiltrates through a calcareous-sandstone aquifer with various amount of adsorbed Mg2+ (3-27 meq/kg). Hence, the higher concentration of Ca+2 in the PTDES together with its higher affinity to the sediments promotes the release of Mg2+ ions to the recharged water. Water isotopes analysis of the production wells were used to estimate residence time and mixing with local groundwater. At the end of 2016, it was found that the percentage of PTDES in adjacent down-gradient production wells was around 10%, while more distant or up-gradient wells show no mixing with PTDES. The distinct isotope contrast between the recharged desalinated seawater (δ2H=+11.2±0.2‰) and the local groundwater (δ2H ranged from -22.7 to -16.7‰) is a promising tool to evaluate future mixing processes at the Menshae MAR site. Using the Menashe MAR system for remineralization could be beneficial as a primary or complementary post-treatment technique. However, the sustainability of this process is

  12. Exploring the influence of land-use and climate on regional hydrology and groundwater recharge

    Science.gov (United States)

    Jayawickreme, Dushmantha Helapriya

    2008-10-01

    Global energy, water, and bio-geochemical cycles are strongly linked to land-use and land-cover characteristics. Land-use and land-cover is also a component of the environment extensively impacted and continuously altered by human activity. Population growth, food, energy and other needs coupled with human ingenuity has greatly altered and will continue to change the terrestrial biosphere across the globe. With additional concerns for significant and widespread land-use/land-cover transformations due to global climate change, a need to better understand the effects of these transformations on environmental systems from local, regional, to global scale has emerged in the recent decades. In this dissertation I have investigated the impacts of land-use and land-cover (i.e. vegetation) on groundwater recharge, which is a critical component of the hydrologic cycle. The dependence of people and many sensitive ecosystems around the world on groundwater alone warranted a closer look at how changing land-use/cover and climate are affecting the quantity and quality of groundwater. By evaluating streamflow, climate, land-cover, and other attributes in Michigan's watersheds we showed that intense agriculture reduced summer time streamflow, hence groundwater recharge in such watersheds. By quantifying baseflow discharges relative to precipitation in July-September peak growing season over multiple years we found that recharge in primarily agricultural (>70 agricultural uses by land area) watersheds was only one third of the recharge in watersheds that are mix use (land-cover; specifically vegetation, vegetation differences, and vegetation dynamics affect recharge we adopted geophysical techniques, a step beyond the traditional uses of geophysical methods as well as an unorthodox approach to terrestrial ecosystem investigations. It was hypothesized that there would be observable differences in the way vegetation interacts with the shallow subsurface and such interactions could

  13. Estimating Recharge through Playa Lakes to the Southern High Plains Aquifer

    Science.gov (United States)

    Rainwater, K.; Ganesan, G.; Gitz, D.; Zartman, R.; Hudnall, W.; Smith, L.

    2009-12-01

    In the Southern High Plains of Texas, it is accepted that focused recharge to the High Plains Aquifer (locally known as the Ogallala) occurs through over 20,000 playa lakes, which are local depressions that collect storm runoff. The amount and rate of recharge is not precisely known, and the impact of the land use surrounding each playa lake on the amount of runoff has not been quantified. Each playa exists within its own watershed, and many of those are cultivated, while others are surrounded by native grassland or conservation reserve program (CRP) lands. The amount of sediments entering most playas following cultivation has been substantial, but whether this erosion has had a harmful influence on recharge is unknown. Changing recharge rates can also impact the playa ecosystems that are pivotal to many types of local wildlife. Improved understanding of playa recharge is necessary for proper management strategies for long-term survivability of the Ogallala aquifer. Over the last four years, the research team selected and instrumented 30 playas (10 counties, one cropland playa, one native grassland playa, one CRP playa in each) for observation of their water budgets. To quantify recharge in each playa, data collection includes sufficient weather instrumentation to determine local precipitation and free water evaporation, as well as water level monitoring in the playa lake. The depth/area/volume relationship for each playa was developed by local GPS surveying. Between rainfall/runoff events, seepage through the playa bottom is calculated as the difference between the change in the volume of water stored in the playa and the calculated free water evaporation. The research team hopes to keep the instrumentation operational for as long as possible, hopefully several years, to observe enough inundation events to characterize a range of behaviors in the different playa basins. In this presentation, initial water budget analyses for several of the initially instrumented

  14. Recharging California's Groundwater: Crop Suitability and Surface Water Availability for Agricultural Groundwater Banking

    Science.gov (United States)

    Dahlke, H. E.; Kocis, T. N.; Brown, A.

    2016-12-01

    Groundwater banking, the intentional recharge of groundwater from surface water for storage and recovery, is an important conjunctive use strategy for water management in California (CA). A largely unexplored approach to groundwater banking, agricultural groundwater banking (ag-GB), utilizes flood flows and agricultural lands (alfalfa/pasture) for recharging groundwater. Understanding soil suitability for ag-GB, crop health and flooding tolerance, leaching of soil nitrate and salts, the availability of surface water for recharge, and the economic costs and benefits of ag-GB is fundamental to assessing the feasibility of local-scale implementation of ag-GB. The study presented here considers both the availability of excess streamflow (e.g., the magnitude, frequency, timing, and duration of winter flood flow) for ag-GB and the risks and benefits associated with using alfalfa fields as spreading grounds for ag-GB. The availability of surface water for winter (Nov to Apr) ag-GB were estimated based on daily streamflow records for 93 stream gauges within the Central Valley, CA. Analysis focused on high-magnitude (>90thpercentile) flows because most lower flows are likely legally allocated in CA. Results based >50 years of data indicate that an average winter/spring (Nov. - Apr.) in the Sacramento River Basin could provide 7 million acre-feet (AF) (8.6 km3) of water for ag-GB from flows above the 90th percentile. These flows originate from few storm events (5-7 events) and occur on average for 25-30 days between November and April. Wintertime on-farm recharge experiments were conducted on a 9-yr old, 15-acre alfalfa field in the Scott Valley, CA, where 135 AF and 107 AF of water were recharged during the winters of 2015 and 2016, respectively. Biomass data collected indicates that pulsed application of 6-10 ft of water on dormant alfalfa results in minimal yield loss (0.5 ton/acre reduction), short-duration saturated conditions in the root-zone, and high recharge

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

    Science.gov (United States)

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

    2015-01-01

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

  16. A fundamental study on the [(μ-Cl)3Mg2(THF)6]+ dimer electrolytes for rechargeable Mg batteries.

    Science.gov (United States)

    Liu, Tianbiao; Cox, Jonathan T; Hu, Dehong; Deng, Xuchu; Hu, Jianzhi; Hu, Mary Y; Xiao, Jie; Shao, Yuyan; Tang, Keqi; Liu, Jun

    2015-02-11

    The long sought solvated [MgCl](+) species in the Mg-dimer electrolytes was characterized by soft mass spectrometry. The presented study provides an insightful understanding on the electrolyte chemistry of rechargeable Mg batteries.

  17. Groundwater recharge estimation in semi-arid zone: a study case from the region of Djelfa (Algeria)

    National Research Council Canada - National Science Library

    Ali Rahmani, S E; Chibane, Brahim; Boucefiène, Abdelkader

    2017-01-01

    .... In this research we are going to quantify the rate of groundwater recharge using new hybrid model tack in interest the annual rainfall and the average annual temperature and the geological characteristics of the area...

  18. High-efficiency and high-power rechargeable lithium-sulfur dioxide batteries exploiting conventional carbonate-based electrolytes

    National Research Council Canada - National Science Library

    Hyeokjun Park; Hee-dae Lim; Hyung-kyu Lim; Won Mo Seong; Sehwan Moon; Youngmin Ko; Byungju Lee; Youngjoon Bae; Hyungjun Kim; Kisuk Kang

    2017-01-01

    .... Recently, the primary lithium-sulfur dioxide battery, which offers a high energy density and long shelf-life, is successfully renewed as a promising rechargeable system exhibiting small polarization...

  19. Cost-Benefit Analysis of the Managed Aquifer Recharge System for Irrigation under Climate Change Conditions in Southern Spain

    National Research Council Canada - National Science Library

    Carmen Ruperez-Moreno; Julio Perez-Sanchez; Javier Senent-Aparicio; Pilar Flores-Asenjo; Carmen Paz-Aparicio

    2017-01-01

    .... In the integrated water resource management (IWRM), managed aquifer recharge (MAR) offers efficient solutions to protect, conserve, and ensure survival of aquifers and associated ecosystems, as the Water Framework Directive requires...

  20. Recycling application of Li-MnO₂ batteries as rechargeable lithium-air batteries.

    Science.gov (United States)

    Hu, Yuxiang; Zhang, Tianran; Cheng, Fangyi; Zhao, Qing; Han, Xiaopeng; Chen, Jun

    2015-03-27

    The ever-increasing consumption of a huge quantity of lithium batteries, for example, Li-MnO2 cells, raises critical concern about their recycling. We demonstrate herein that decayed Li-MnO2 cells can be further utilized as rechargeable lithium-air cells with admitted oxygen. We further investigated the effects of lithiated manganese dioxide on the electrocatalytic properties of oxygen-reduction and oxygen-evolution reactions (ORR/OER). The catalytic activity was found to be correlated with the composition of Li(x)MnO2 electrodes (0batteries can be prolonged by their application as rechargeable lithium-air batteries. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. High capacity WO3 film as efficient charge collection electrode for solar rechargeable batteries

    Science.gov (United States)

    Zhao, Wenjie; Wang, Xiao-Feng; Zheng, Enqiang; Wei, Yingjin; Sanehira, Yoshitaka; Chen, Gang

    2017-05-01

    In this work, we demonstrated the dye-sensitized solar rechargeable batteries devices sharing a structure of Dye-TiO2/electrolyte/Ni/WO3. The WO3 film was prepared by a simple sol-gel process exhibit high cavities and large surface area allowing efficient chemical/electrical reactions. The WO3 films with 2 ± 0.5 μm in thickness as charge collection electrodes exhibited a high energy density over other materials reported thus far. Under irradiation energy of 7.5 mWcm-2 in the photo-charging, the discharging time sustained 1758 s at the current density of 0.05 mA cm-2 in dark, the first specific discharge capacities of WO3 nano-film reach 40.6 mAh g-1 (0.0244 mAh cm-2). This work substantially pushes forward the easy processing solar rechargeable batteries for future potential applications.

  2. Characterization of rechargeable lithium cells. Part 1. Lithium/niobium triselenide chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, T.C.; Cason-Smith, D.M.; Smith, P.H.; James, S.D.

    1994-08-16

    The Naval Surface Warfare Center is evaluating industry's emerging lithium rechargeable battery technology for use in underwater vehicle applications. The battery industry typically characterizes cells for consumer applications requiring low rate cycling at room temperature and rarely provides high rate, low temperature data. High rate and low temperature performance of ATT's lithium/niobium triselenide(Li/NbSe3)AA cells is reported here. At 25 deg C and 1O mA/sq cm (approximately the 3C rate), delivered energy densities were as high as 30 Wh/lb. However, these lithium cells proved vulnerable to performance loss in low temperature (O deg C), high discharge rate cycling. Lithium/niobium triselenide, NbSe3, Lithium batteries, Rechargeable AA cells.

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

    Science.gov (United States)

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

    2015-09-17

    Historically, the city of Palmdale and vicinity have relied on groundwater as the primary source of water, owing, in large part, to the scarcity of surface water in the region. Despite recent importing of surface water, groundwater withdrawal for municipal, industrial, and agricultural use has resulted in groundwater-level declines near the city of Palmdale in excess of 200 feet since the early 1900s. To meet the growing water demand in the area, the city of Palmdale has proposed the Amargosa Creek Recharge Project (ACRP), which has a footprint of about 150 acres along the Amargosa Creek 2 miles west of Palmdale, California. The objective of this study was to evaluate the long-term feasibility of recharging the Antelope Valley aquifer system by using infiltration of imported surface water from the California State Water Project in percolation basins at the ACRP.

  4. Zero Emission Mobility Systems in Cities. Inductive Recharge System Planning in Urban Areas

    Directory of Open Access Journals (Sweden)

    Giulio Maternini

    2014-05-01

    Full Text Available In the last few years, “Sustainable” and “Smart” mobility became concepts of fundamental importance and led national government to adopt programmes and measures aimed at reducing the carbon emissions of private and commercial vehicles. The final goal is to pursue the EU objectives of reducing the greenhouse gases emission in transportation sector. The progressive electrification of the circulating vehicles represents a possible solution to the air pollution relating problems. A recent innovative research field, which could significantly contribute to the diffusion of the electric vehicles, consists of the inductive recharge systems for electric vehicles. This technology could also bring to considerably environmental and logistic advantages, especially in urban areas. Starting from the analysis of the main ongoing experimentations of these innovative systems in the world, the present paper proposes a possible application of the inductive recharge technology to the public transport vehicles, through the presentation of the case study of Brescia.

  5. The impact of a shallow biobarrier on water recharge patterns in a semi-arid environment

    Energy Technology Data Exchange (ETDEWEB)

    Laundre, J.W. [Idaho State Univ., Pocatello, ID (United States)

    1997-12-31

    This study attempted to measure the effect of a shallow biobarrier of gravel and cobble on water flow patterns during spring snow melt and recharge. The design consisted of 30 metal culverts 3 m in diameter and 1.6 m long, positioned on end. Test culverts contained 50-cm biobarrier of gravel or cobble and then an additional 50 cm of soil placed above the barrier layer. A neutron probe was used to measure soil moisture above and below the barrier. Measurements were made in the fall and again immediately after snow melt in the spring. During recharge, the biobarriers provided a capillary break which resulted in a pooling of water above the barrier layer. With sufficient snowmelt, the water can penetrate the break and possibly penetrate deeper than in the absence of the barrier layer.

  6. Binder-free V2O5 cathode for greener rechargeable aluminum battery.

    Science.gov (United States)

    Wang, Huali; Bai, Ying; Chen, Shi; Luo, Xiangyi; Wu, Chuan; Wu, Feng; Lu, Jun; Amine, Khalil

    2015-01-14

    This letter reports on the investigation of a binder-free cathode material to be used in rechargeable aluminum batteries. This cathode is synthesized by directly depositing V2O5 on a Ni foam current collector. Rechargeable aluminum coin cells fabricated using the as-synthesized binder-free cathode delivered an initial discharge capacity of 239 mAh/g, which is much higher than that of batteries fabricated using a cathode composed of V2O5 nanowires and binder. An obvious discharge voltage plateau appeared at 0.6 V in the discharge curves of the Ni-V2O5 cathode, which is slightly higher than that of the V2O5 nanowire cathodes with common binders. This improvement is attributed to reduced electrochemical polarization.

  7. Ground water recharge to the aquifers of northern San Luis Valley, Colorado: A remote sensing investigation

    Science.gov (United States)

    Lee, K. (Principal Investigator); Huntley, D.

    1976-01-01

    The author has identified the following significant results. Ground water recharge to the aquifers of San Luis Valley west of San Luis Creek was primarily from ground water flow in the volcanic aquifers of the San Juan Mountains. The high permeability and anisotropic nature of the volcanic rocks resulted in very little contrast in flow conditions between the San Juan Mountains and San Luis Valley. Ground water recharge to aquifers of eastern San Luis Valley was primarily from stream seepage into the upper reaches of the alluvial fans at the base of the Sangre de Cristo Mountains. The use of photography and thermal infrared imagery resulted in a savings of time and increase in accuracy in regional hydrogeologic studies. Volcanic rocks exhibited the same spectral reflectance curve as sedimentary rocks, with only the absolute magnitude of reflectance varying. Both saline soils and vegetation were used to estimate general ground water depths.

  8. Estimation of Shallow Groundwater Recharge Using a Gis-Based Distributed Water Balance Model

    Directory of Open Access Journals (Sweden)

    Graf Renata

    2014-09-01

    Full Text Available In the paper we present the results of shallow groundwater recharge estimation using the WetSpass GISbased distributed water balance model. By taking into account WetSpass, which stands for Water an Energy Transfer between Soil, Plants and Atmosphere under quasi-Steady State, for average conditions during the period 1961-2000, we assessed the spatial conditions of the groundwater infiltration recharge process of shallow circulation systems in the Poznan Plateau area (the Great Poland Lowland in western Poland, which is classified as a region with observed water deficits. For three temporal variants, i.e. year, winter and summer half-years, we determined using the geological infiltration method by about 5-10% on average, marginally by 20%.

  9. Durable rechargeable zinc-air batteries with neutral electrolyte and manganese oxide catalyst

    Science.gov (United States)

    Sumboja, Afriyanti; Ge, Xiaoming; Zheng, Guangyuan; Goh, F. W. Thomas; Hor, T. S. Andy; Zong, Yun; Liu, Zhaolin

    2016-11-01

    Neutral chloride-based electrolyte and directly grown manganese oxide on carbon paper are used as the electrolyte and air cathode respectively for rechargeable Zn-air batteries. Oxygen reduction and oxygen evolution reactions on manganese oxide show dependence of activities on the pH of the electrolyte. Zn-air batteries with chloride-based electrolyte and manganese oxide catalyst exhibit satisfactory voltage profile (discharge and charge voltage of 1 and 2 V at 1 mA cm-2) and excellent cycling stability (≈90 days of continuous cycle test), which is attributed to the reduced carbon corrosion on the air cathode and decreased carbonation in neutral electrolyte. This work describes a robust electrolyte system that improves the cycle life of rechargeable Zn-air batteries.

  10. NANOSTRUCTURED METAL OXIDES FOR ANODES OF LI-ION RECHARGEABLE BATTERIES

    Energy Technology Data Exchange (ETDEWEB)

    Au, M.

    2009-12-04

    The aligned nanorods of Co{sub 3}O{sub 4} and nanoporous hollow spheres (NHS) of SnO{sub 2} and Mn{sub 2}O{sub 3} were investigated as the anodes for Li-ion rechargeable batteries. The Co{sub 3}O{sub 4} nanorods demonstrated 1433 mAh/g reversible capacity. The NHS of SnO{sub 2} and Mn{sub 2}O{sub 3} delivered 400 mAh/g and 250 mAh/g capacities respectively in multiple galvonastatic discharge-charge cycles. It was found that high capacity of NHS of metal oxides is sustainable attributed to their unique structure that maintains material integrity during cycling. The nanostructured metal oxides exhibit great potential as the new anode materials for Li-ion rechargeable batteries with high energy density, low cost and inherent safety.

  11. La2O3 hollow nanospheres for high performance lithium-ion rechargeable batteries.

    Science.gov (United States)

    Sasidharan, Manickam; Gunawardhana, Nanda; Inoue, Masamichi; Yusa, Shin-ichi; Yoshio, Masaki; Nakashima, Kenichi

    2012-03-28

    An efficient and simple protocol for synthesis of novel La(2)O(3) hollow nanospheres of size about 30 ± 2 nm using polymeric micelles is reported. The La(2)O(3) hollow nanospheres exhibit high charge capacity and cycling performance in lithium-ion rechargeable batteries (LIBs), which was scrutinized for the first time among the rare-earth oxides. This journal is © The Royal Society of Chemistry 2012

  12. Estimation of Groundwater Recharge at Pahute Mesa using the Chloride Mass-Balance Method

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Clay A [DRI; Hershey, Ronald L [DRI; Healey, John M [DRI; Lyles, Brad F [DRI

    2013-07-01

    Groundwater recharge on Pahute Mesa was estimated using the chloride mass-balance (CMB) method. This method relies on the conservative properties of chloride to trace its movement from the atmosphere as dry- and wet-deposition through the soil zone and ultimately to the saturated zone. Typically, the CMB method assumes no mixing of groundwater with different chloride concentrations; however, because groundwater is thought to flow into Pahute Mesa from valleys north of Pahute Mesa, groundwater flow rates (i.e., underflow) and chloride concentrations from Kawich Valley and Gold Flat were carefully considered. Precipitation was measured with bulk and tipping-bucket precipitation gauges installed for this study at six sites on Pahute Mesa. These data, along with historical precipitation amounts from gauges on Pahute Mesa and estimates from the PRISM model, were evaluated to estimate mean annual precipitation. Chloride deposition from the atmosphere was estimated by analyzing quarterly samples of wet- and dry-deposition for chloride in the bulk gauges and evaluating chloride wet-deposition amounts measured at other locations by the National Atmospheric Deposition Program. Mean chloride concentrations in groundwater were estimated using data from the UGTA Geochemistry Database, data from other reports, and data from samples collected from emplacement boreholes for this study. Calculations were conducted assuming both no underflow and underflow from Kawich Valley and Gold Flat. Model results estimate recharge to be 30 mm/yr with a standard deviation of 18 mm/yr on Pahute Mesa, for elevations >1800 m amsl. These estimates assume Pahute Mesa recharge mixes completely with underflow from Kawich Valley and Gold Flat. The model assumes that precipitation, chloride concentration in bulk deposition, underflow and its chloride concentration, have been constant over the length of time of recharge.

  13. Synchrotron X-ray Analytical Techniques for Studying Materials Electrochemistry in Rechargeable Batteries.

    Science.gov (United States)

    Lin, Feng; Liu, Yijin; Yu, Xiqian; Cheng, Lei; Singer, Andrej; Shpyrko, Oleg G; Xin, Huolin L; Tamura, Nobumichi; Tian, Chixia; Weng, Tsu-Chien; Yang, Xiao-Qing; Meng, Ying Shirley; Nordlund, Dennis; Yang, Wanli; Doeff, Marca M

    2017-09-29

    Rechargeable battery technologies have ignited major breakthroughs in contemporary society, including but not limited to revolutions in transportation, electronics, and grid energy storage. The remarkable development of rechargeable batteries is largely attributed to in-depth efforts to improve battery electrode and electrolyte materials. There are, however, still intimidating challenges of lower cost, longer cycle and calendar life, higher energy density, and better safety for large scale energy storage and vehicular applications. Further progress with rechargeable batteries may require new chemistries (lithium ion batteries and beyond) and better understanding of materials electrochemistry in the various battery technologies. In the past decade, advancement of battery materials has been complemented by new analytical techniques that are capable of probing battery chemistries at various length and time scales. Synchrotron X-ray techniques stand out as one of the most effective methods that allow for nearly nondestructive probing of materials characteristics such as electronic and geometric structures with various depth sensitivities through spectroscopy, scattering, and imaging capabilities. This article begins with the discussion of various rechargeable batteries and associated important scientific questions in the field, followed by a review of synchrotron X-ray based analytical tools (scattering, spectroscopy, and imaging) and their successful applications (ex situ, in situ, and in operando) in gaining fundamental insights into these scientific questions. Furthermore, electron microscopy and spectroscopy complement the detection length scales of synchrotron X-ray tools and are also discussed toward the end. We highlight the importance of studying battery materials by combining analytical techniques with complementary length sensitivities, such as the combination of X-ray absorption spectroscopy and electron spectroscopy with spatial resolution, because a sole

  14. Rocks, Clays, Water, and Salts: Highly Durable, Infinitely Rechargeable, Eminently Controllable Thermal Batteries for Buildings

    OpenAIRE

    Rempel, Alan W.; Alexandra R. Rempel

    2013-01-01

    Materials that store the energy of warm days, to return that heat during cool nights, have been fundamental to vernacular building since ancient times. Although building with thermally rechargeable materials became a niche pursuit with the advent of fossil fuel-based heating and cooling, energy and climate change concerns have sparked new enthusiasm for these substances of high heat capacity and moderate thermal conductivity: stone, adobe, rammed earth, brick, water, concrete, and more recent...

  15. Effects of Soil and Water Conservation Measures on Groundwater Levels and Recharge

    OpenAIRE

    Hong Wang; Jianen Gao; Xinghua Li; Hongjie Wang; Yuanxing Zhang

    2014-01-01

    Measures of soil and water conservation (SWC) could affect the hydrological process. The impacts of typical measures on groundwater recharge, levels and flow were analyzed based on simulated rainfall experiments and a groundwater model. The three-dimensional finite-difference groundwater flow model (MODFLOW) was calibrated and verified for bare slope, grassland and straw mulching scenarios based on the experiments. The results of the verification in groundwater balance, levels, runoff and fl...

  16. Isotope investigation on groundwater recharge and dynamics in shallow and deep alluvial aquifers of southwest Punjab.

    Science.gov (United States)

    Keesari, Tirumalesh; Sharma, Diana A; Rishi, Madhuri S; Pant, Diksha; Mohokar, Hemant V; Jaryal, Ajay Kumar; Sinha, U K

    2017-11-01

    Groundwater samples collected from the alluvial aquifers of southwest Punjab, both shallow and deep zones were measured for environmental tritium ( 3 H) and stable isotopes ( 2 H and 18 O) to evaluate the source of recharge and aquifer dynamics. The shallow groundwater shows wide variation in isotopic signature (δ 18 O: -11.3 to -5.0‰) reflecting multiple sources of recharge. The average isotopic signature of shallow groundwaters (δ 18 O: -6.73 ± 1.03‰) is similar to that of local precipitation (-6.98 ± 1.66‰) indicating local precipitation contributes to a large extent compared to other sources. Other sources have isotopically distinct signatures due to either high altitude recharge (canal sources) or evaporative enrichment (irrigation return flow). Deep groundwater shows relatively depleted isotopic signature (δ 18 O: -8.6‰) and doesn't show any evaporation effect as compared to shallow zone indicating recharge from precipitation occurring at relatively higher altitudes. Environmental tritium indicates that both shallow ( 3 H: 5 - 10 T.U.) and deeper zone ( 3 H: 1.5 - 2.5 T.U.) groundwaters are modern. In general the inter-aquifer connections seem to be unlikely except a few places. Environmental isotope data suggests that shallow groundwater is dynamic, local and prone to changes in land use patterns while deep zone water is derived from distant sources, less dynamic and not impacted by surface manifestations. A conceptual groundwater flow diagram is presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Evapotranspiration Dynamics and Effects on Groundwater Recharge and Discharge at the Tuba City, Arizona, Disposal Site

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-02-01

    The U.S. Department of Energy Office of Legacy Management is evaluating groundwater flow and contaminant transport at a former uranium mill site near Tuba City, Arizona. We estimated effects of temporal and spatial variability in evapotranspiration (ET) on recharge and discharge within a groundwater model domain (GMD) as part of this evaluation. We used remote sensing algorithms and precipitation (PPT) data to estimate ET and the ET/PPT ratios within the 3531 hectare GMD. For the period from 2000 to 2012, ET and PPT were nearly balanced (129 millimeters per year [mm yr-1] and 130 mm yr-1, respectively; ET/PPT = 0.99). However, seasonal and annual variability in ET and PPT were out of phase, and spatial variability in vegetation differentiated discharge and recharge areas within the GMD. Half of ET occurred during spring and early summer when PPT was low, and about 70% of PPT arriving in fall and winter was discharged as plant transpiration in the spring and summer period. Vegetation type and health had a significant effect on the site water balance. Plant cover and ET were significantly higher (1) during years of lighter compared to years of heavier grazing pressure, and (2) on rangeland protected from grazing compared to rangeland grazed by livestock. Heavy grazing increased groundwater recharge (PPT > ET over the 13-year period). Groundwater discharge (ET > PPT over the 13-year period) was highest in riparian phreatophyte communities but insignificant in desert phreatophyte communities impacted by heavy grazing. Grazing management in desert upland and phreatophyte communities may result in reduced groundwater recharge, increased groundwater discharge, and could be used to influence local groundwater flow.

  18. Using natural distributions of short-lived radium isotopes to quantify groundwater discharge and recharge

    Science.gov (United States)

    Krest, J.M.; Harvey, J.W.

    2003-01-01

    Radium activity in pore water of wetland sediments often differs from the amount expected from local production, decay, and exchange with solid phases. This disequilibrium results from vertical transport of radium with groundwater that flows between the underlying aquifer and surface water. In situations where groundwater recharge or discharge is significant, the rate of vertical water flow through wetland sediment can be determined from the radium disequilibrium by a combined model of transport, production, decay, and exchange with solid phases. We have developed and tested this technique at three sites in the freshwater portion of the Everglades by quantifying vertical advective velocities in areas with persistent groundwater recharge or discharge and estimating a coefficient of dispersion at a site that is subject to reversals between recharge and discharge. Groundwater velocities (v) were determined to be between 0 and -0.5 cm d-1 for a recharge site and 1.5 ?? 0.4 cm d-1 for a discharge site near Levee 39 in the Everglades. Strong gradients in 223Ra and 224Ra usually occurred at the base of the peat layer, which avoided the problems of other tracers (e.g., chloride) for which greatest sensitivity occurs near the peat surface - a zone readily disturbed by processes unrelated to groundwater flow. This technique should be easily applicable to any wetland system with different production rates of these isotopes in distinct sedimentary layers or surface water. The approach is most straightforward in systems where constant pore-water ionic strength can be assumed, simplifying the modeling of radium exchange.

  19. Understanding regional and local scale hydraulic processes controlling recharge through drift

    Science.gov (United States)

    Cuthbert, M. O.; Mackay, R.; Lawrence, A. R.; Peach, D.

    2003-04-01

    The estimation of groundwater recharge is a fundamental component of any water resources appraisal or aquifer vulnerability study. Although methods for evaluating the distribution of potential recharge leaving the soil zone are relatively well developed, the recharge signal to the underlying aquifer can be significantly modified in the presence of superficial drift deposits. Current mapping of the drift does not often provide representations of drift distribution and structure suitable for understanding the hydraulics of the subsurface flow system. The current research seeks to develop new understanding of the processes contributing to recharge in heterogeneous drift sequences, their characterisation in models and their parameterisation through field experiments. Surface and downhole geophysical sampling through regional to micro scales will be integrated with textural measurements and hydraulic monitoring to characterise drift deposits in parts of the Tern catchment (Shropshire, UK) and gain insight into the relationship between flow behaviour and geological structure. Fieldwork will then culminate in a series of flow and tracer tests at a well characterised site with continuous monitoring including the use of recently developed 4-D resistivity imaging methods to monitor the movement of natural and applied waters through the drift. Conceptual and numerical models will be used throughout the project to test ideas and drive the experimental designs. The study aims to assess the relative importance of hydraulic processes at a range of scales and, by back analysis, the degree of sophistication required in fieldwork to construct a useful model of flow patterns within the drift. The potential usefulness of various surface and downhole geophysical techniques within drift and unsaturated zone studies will be critically assessed.

  20. Stable H and O isotope variations reveal sources of recharge in Dhofar, Sultanate of Oman.

    Science.gov (United States)

    Strauch, Gerhard; Al-Mashaikhi, Khalid S; Bawain, Abdullah; Knöller, Kay; Friesen, Jan; Müller, Thomas

    2014-01-01

    Due to the ability of stable water isotopes to characterize the origin of water and connected processes of groundwater recharge, we used the isotope variations of hydrogen and oxygen in different water sources for assessing the recharge process in the Dhofar region. δ(18)O and δ(2)H of precipitation, spring water, and groundwater cover a range from -10 to +2 and from -70 to +7 ‰ (vs Vienna Standard Mean Ocean Water), respectively, and correlate in a linear relationship close to the Global Meteoric Water Line. No obvious evaporation processes are detected. A clear signal of the recent precipitation is given by the annual monsoon. The monsoon signal is confirmed by several springs existing in the south at the foot of the Dhofar mountains and sources at Gogub above 450 m and Tawi Atir at 650 m above sea level. They occur here first in the form of water intercepted by trees as stemflow and throughflow. The isotope signature of groundwater in the Dhofar mountains reflects the climatic conditions at the time of recharge and the lithological features of the limestone matrix. To the north, the isotope patterns of the groundwater are continuously depleted from the monsoon signal along the outcropping aquifer D (Lower Umm Er Radhuma). Here, a more negative signature towards the wells in the Najd desert region was observed. Cyclone water that flooded wadis in the Dhofar region occasionally, as observed in November 2011, falls isotopically into the same range as we observed in the fossil groundwater. Taking into account the different sources of precipitation and groundwater and thus a clear distinction of the isotopic composition of the water sources, we conclude a recharge process divided into a southward and a northward component in the Dhofar region.

  1. Introducing sequential managed aquifer recharge technology (SMART) - From laboratory to full-scale application.

    Science.gov (United States)

    Regnery, Julia; Wing, Alexandre D; Kautz, Jessica; Drewes, Jörg E

    2016-07-01

    Previous lab-scale studies demonstrated that stimulating the indigenous soil microbial community of groundwater recharge systems by manipulating the availability of biodegradable organic carbon (BDOC) and establishing sequential redox conditions in the subsurface resulted in enhanced removal of compounds with redox-dependent removal behavior such as trace organic chemicals. The aim of this study is to advance this concept from laboratory to full-scale application by introducing sequential managed aquifer recharge technology (SMART). To validate the concept of SMART, a full-scale managed aquifer recharge (MAR) facility in Colorado was studied for three years that featured the proposed sequential configuration: A short riverbank filtration passage followed by subsequent re-aeration and artificial recharge and recovery. Our findings demonstrate that sequential subsurface treatment zones characterized by carbon-rich (>3 mg/L BDOC) to carbon-depleted (≤1 mg/L BDOC) and predominant oxic redox conditions can be established at full-scale MAR facilities adopting the SMART concept. The sequential configuration resulted in substantially improved trace organic chemical removal (i.e. higher biodegradation rate coefficients) for moderately biodegradable compounds compared to conventional MAR systems with extended travel times in an anoxic aquifer. Furthermore, sorption batch experiments with clay materials dispersed in the subsurface implied that sorptive processes might also play a role in the attenuation and retardation of chlorinated flame retardants during MAR. Hence, understanding key factors controlling trace organic chemical removal performance during SMART allows for systems to be engineered for optimal efficiency, resulting in improved removal of constituents at shorter subsurface travel times and a potentially reduced physical footprint of MAR installations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Estimating aquifer properties and distributed groundwater recharge in a hard-rock catchment of Udaipur, India

    Science.gov (United States)

    Machiwal, Deepesh; Singh, P. K.; Yadav, K. K.

    2017-10-01

    The present study determined aquifer parameters in hard-rock aquifer system of Ahar River catchment, Udaipur, India by conducting 19 pumping tests in large-diameter wells. Spreadsheet programs were developed for analyzing pumping test data, and their accuracy was evaluated by root mean square error (RMSE) and correlation coefficient ( R). Histograms and Shapiro-Wilk test indicated non-normality ( p value groundwater levels at 50 sites for years 2006-2008, and hence, logarithmic transformations were done. Furthermore, recharge was estimated using GIS-based water table fluctuation method. The groundwater levels were found to be influenced by the topography, presence of structural hills, density of pumping wells, and seasonal recharge. The results of the pumping tests revealed that the transmissivity ( T) ranges from 68-2239 m2/day, and the specific yield ( S y) varies from 0.211 to 0.51 × 10-5. The T and S y values were found reasonable for the hard-rock formations in the area, and the spreadsheet programs were found reliable (RMSE 0.017-0.339 m; R > 0.95). Distribution of the aquifer parameters and recharge indicated that the northern portion with high ground elevations (575-700 m MSL), and high S y (0.08-0.25) and T (>600 m2/day) values may act as recharge zone. The T and S y values revealed significant spatial variability, which suggests strong heterogeneity of the hard-rock aquifer system. Overall, the findings of this study are useful to formulate appropriate strategies for managing water resources in the area. Also, the developed spreadsheet programs may be used to analyze the pumping test data of large-diameter wells in other hard-rock regions of the world.

  3. Application of Inverse Modeling to Estimate Groundwater Recharge under Future Climate Scenario

    Science.gov (United States)

    Akbariyeh, S.; Wang, T.; Bartelt-Hunt, S.; Li, Y.

    2016-12-01

    Climate variability and change will impose profound influences on groundwater systems. Accurate estimation of groundwater recharge is extremely important for predicting the flow and contaminant transport in the subsurface, which, however, remains as one of the most challenging tasks in the field of hydrology. Using an inverse modeling technique and HYDRUS 1D software, we predicted the spatial distribution of groundwater recharge across the Upper Platte basin in Nebraska, USA, based on 5-year projected future climate and soil moisture data (2057-2060). The climate data was obtained from Weather Research and Forecasting (WRF) model under RCP 8.5 scenario, which was downscaled from global CCSM4 model to a resolution of 24 by 24 km2. Precipitation, potential evapotranspiration, and soil moisture data were extracted from 76 grids located within the Upper Platte basin to perform the inverse modeling. Hargreaves equation was used to calculate the potential evapotranspiration according to latitude, maximum and minimum temperature, and leaf area index (LAI) data at each node. Van-Genuchten parameters were optimized using the inverse algorithm to minimize the error between input and modeled soil moisture data. The groundwater recharge was calculated as the amount of water that passed the lower boundary of the best fitted model. The year of 2057 was used as a spin-up period to minimize the impact of initial conditions. The model was calibrated for years 2058 to 2059 and validation was performed for 2060. This work demonstrates an efficient approach to estimating groundwater recharge based on climate modeling results, which will aid groundwater resources management under future climate scenarios.

  4. Performance Evaluation of an Autonomous Photovoltaic System for Recharging Electrical Vehicle Batteries

    OpenAIRE

    Benaouadj, M.; Aboubou, A.; Ayad, M.Y; Becherif, M.; Akhrif, O.

    2015-01-01

    – This paper deals with the performance evaluation of an autonomous photovoltaic system for recharging (with electrical power produced by photovoltaic panels) Lithium-ion batteries for an electrical vehicle. In this system, the power flow control is performed via a DC-DC converter using a Maximum Power Point Tracking (MPPT) technique. The performance evaluation is according to two operation modes: under degraded and optimal conditions

  5. The impact of rechargeable batteries: quantifying the cost and weight for a Marine Infantry Battalion

    OpenAIRE

    Brown, Darrell H.

    2011-01-01

    Since the implementation of distributed operations with a higher density of tactical field radios, optics and electrical tactical equipment, the demand for batteries has increased significantly. While advances in technology have increased the lethality of Defense (DoD) forces, sustainment and increased resupply convoys have increased the risk of logistical support and costs. This thesis examines the viability, cost savings, and operational weight associated with the use of rechargeable bat...

  6. Quantifying the impact of climate change on groundwater resources of Bascombe well conservation park area by estimating recharge rates.

    OpenAIRE

    Karbasi, Mojtaba

    2015-01-01

    Access to surface water is limited in Australia and many regions rely on groundwater for all their water needs. Most of aquifers are already fully allocated and there is an increasing demand for more extraction. During drought, drop in rainfall can result in less recharge into groundwater system. Decrease in rainfall can cause direct and indirect impacts on groundwater. Drop in rainfall can result in less recharge into groundwater system. Moreover decreased rainfall can cause limited accessib...

  7. Groundwater recharge mechanism in an integrated tableland of the Loess Plateau, northern China: insights from environmental tracers

    Science.gov (United States)

    Huang, Tianming; Pang, Zhonghe; Liu, Jilai; Ma, Jinzhu; Gates, John

    2017-11-01

    Assessing groundwater recharge characteristics (recharge rate, history, mechanisms (piston and preferential flow)) and groundwater age in arid and semi-arid environments remains a difficult but important research frontier. Such assessments are particularly important when the unsaturated zone (UZ) is thick and the recharge rate is limited. This study combined evaluations of the thick UZ with those of the saturated zone and used multiple tracers, such as Cl, NO3, Br, 2H, 18O, 13C, 3H and 14C, to study groundwater recharge characteristics in an integrated loess tableland in the Loess Plateau, China, where precipitation infiltration is the only recharge source for shallow groundwater. The results indicate that diffuse recharge beneath crops, as the main land use of the study area, is 55-71 mm yr-1 based on the chloride mass balance of soil profiles. The length of time required for annual precipitation to reach the water table is 160-400 yrs. The groundwater is all pre-modern water and paleowater, with corrected 14C age ranging from 136 to 23,412 yrs. Most of the water that eventually becomes recharge originally infiltrated in July-September. The Cl and NO3 contents in the upper UZ are considerably higher than those in the deep UZ and shallow groundwater because of recent human activities. The shallow groundwater has not been in hydraulic equilibrium with present near-surface boundary conditions. The homogeneous material of the UZ and relatively old groundwater age imply that piston flow is the dominant recharge mechanism for the shallow groundwater in the tableland.

  8. Groundwater recharge mechanism in an integrated tableland of the Loess Plateau, northern China: insights from environmental tracers

    Science.gov (United States)

    Huang, Tianming; Pang, Zhonghe; Liu, Jilai; Ma, Jinzhu; Gates, John

    2017-05-01

    Assessing groundwater recharge characteristics (recharge rate, history, mechanisms (piston and preferential flow)) and groundwater age in arid and semi-arid environments remains a difficult but important research frontier. Such assessments are particularly important when the unsaturated zone (UZ) is thick and the recharge rate is limited. This study combined evaluations of the thick UZ with those of the saturated zone and used multiple tracers, such as Cl, NO3, Br, 2H, 18O, 13C, 3H and 14C, to study groundwater recharge characteristics in an integrated loess tableland in the Loess Plateau, China, where precipitation infiltration is the only recharge source for shallow groundwater. The results indicate that diffuse recharge beneath crops, as the main land use of the study area, is 55-71 mm yr-1 based on the chloride mass balance of soil profiles. The length of time required for annual precipitation to reach the water table is 160-400 yrs. The groundwater is all pre-modern water and paleowater, with corrected 14C age ranging from 136 to 23,412 yrs. Most of the water that eventually becomes recharge originally infiltrated in July-September. The Cl and NO3 contents in the upper UZ are considerably higher than those in the deep UZ and shallow groundwater because of recent human activities. The shallow groundwater has not been in hydraulic equilibrium with present near-surface boundary conditions. The homogeneous material of the UZ and relatively old groundwater age imply that piston flow is the dominant recharge mechanism for the shallow groundwater in the tableland.

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

    Science.gov (United States)

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

    2017-11-01

    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.

  10. Assessment of small-diameter shallow wells for managed aquifer recharge at a site in southern Styria, Austria

    Science.gov (United States)

    Händel, Falk; Liu, Gaisheng; Fank, Johann; Friedl, Franz; Liedl, Rudolf; Dietrich, Peter

    2016-12-01

    An approach to establish the recharge component of managed aquifer recharge (MAR) has recently been proposed that uses small-diameter shallow wells installed using relatively inexpensive drilling methods such as direct push. As part of further development of that approach, a generalized procedure is presented for a technical and economic assessment of the approach's potential in comparison to other systems. Following this procedure, the use of small-diameter wells was evaluated both experimentally and numerically for a site located in southern Styria, Austria. MAR is currently done at the site using a horizontal pipe infiltration system, and system expansion has been proposed with a target rate of 12 l/s using small-diameter wells as one possible option. A short-duration single-well field recharge experiment (recharge rate 1.3-3.5 l/s) was performed (recharge by gravity only). Numerical modeling of the injection test was used to estimate hydraulic conductivity ( K). Quasi-steady-state, single-well recharge simulations for different locations, as well as a long-term transient simulation, were performed using the K value calibrated from the field injection test. Results indicate that a recharge capacity of 4.1 l/s was achievable with a maximum head rise of 0.2 m at the injection well. Finally, simulations were performed for three different well fields (4, 6 and 8 wells, respectively) designed to infiltrate a target rate of 12 l/s. The experimental and numerical assessments, supported by a cost analysis of the small-diameter wells, indicate that the small-diameter wells are a viable, cost-effective recharge approach at this and other similar sites.

  11. Natural Recharge to the Unconfined Aquifer System on the Hanford Site from the Greater Cold Creek Watershed: Progress Report 2004

    Energy Technology Data Exchange (ETDEWEB)

    Waichler, Scott R.; Wigmosta, Mark S.; Coleman, Andre M.

    2004-09-14

    Movement of contaminants in groundwater at the Hanford Site is heavily dependent on recharge to the unconfined aquifer. As the effects of past artificial discharges dissipate, the water table is expected to return to more natural conditions, and natural recharge will become the driving force when evaluating future groundwater flow conditions and related contaminant transport. Previous work on the relationship of natural recharge to groundwater movement at the Hanford Site has focused on direct recharge from infiltrating rainfall and snowmelt within the area represented by the Sitewide Groundwater Model (SGM) domain. However, part of the groundwater recharge at Hanford is provided by flow from Greater Cold Creek watershed (GCC), a large drainage area on the western boundary of the Hanford Site that includes Cold Creek Valley, Dry Creek Valley, and the Hanford side of Rattlesnake Mountain. This study was undertaken to estimate the recharge from GCC, which is believed to enter the unconfined aquifer as both infiltrating streamflow and shallow subsurface flow. To estimate recharge, the Distributed Hydrology-Soil-Vegetation Model (DHSVM) was used to simulate a detailed water balance of GCC from 1956 to 2001 at a spatial resolution of 200~m and a temporal resolution of one hour. For estimating natural recharge to Hanford from watersheds along its western and southwestern boundaries, the most important aspects that need to be considered are 1)~distribution and relative magnitude of precipitation and evapotranspiration over the watershed, 2)~streamflow generation at upper elevations and infiltration at lower elevations during rare runoff events, and 3)~permeability of the basalt bedrock surface underlying the soil mantle.

  12. ENSO dynamics and diversity resulting from the recharge oscillator interacting with the slab ocean

    Science.gov (United States)

    Yu, Yanshan; Dommenget, Dietmar; Frauen, Claudia; Wang, Gang; Wales, Scott

    2016-03-01

    El Nino-Southern Oscillation (ENSO) is the leading mode of interannual global climate variability, which in its essence is often described by the equatorial dynamics of the recharge oscillator with a fixed pattern. Here we explore the idea that ENSO can be simulated in a model with a fixed pattern of sea surface temperature variability following the recharge oscillator mechanism, which interacts with the thermodynamic red noise of a slab ocean. This model is capable of simulating the leading modes of sea surface temperature variability in the tropical Pacific in good agreement with the observations and most coupled general circulation models. ENSO dynamics, amplitude, seasonality, the structure of the leading patterns, its meridional extension, its variations in an eastern and central Pacific pattern and associated positive feedbacks are all influenced and simulated well by including the interaction of recharge oscillator and the thermodynamic coupling to the slab ocean model. We further point out that much of the ENSO diversity in the spatial structure is a reflection of this interaction. However, it also has to be noted that some equatorial dynamics are missing in this model and in coupled general circulation models that are important for the ENSO diversity.

  13. Anthropogenic-Induced Changes in the Mechanism of Drylands Ephemeral Stream Recharge, Western Saudi Arabia

    KAUST Repository

    Jadoon, Khan

    2016-04-07

    Wadi aquifers in Saudi Arabia historically have been recharged primarily by channel loss (infiltration) during floods. Historically, seasonal groundwater levels fluctuated from land surface to about 3 m below the surface. Agricultural irrigation pumping has lowered the water table up to 35 m below the surface. The geology surrounding the fluvial system at Wadi Qidayd consists of pelitic Precambrian rocks that contribute sediments ranging in size from mud to boulders to the alluvium. Sediments within the wadi channel consist of fining upward, downstream-dipping beds, causing channel floodwaters to pass through several sediment sequences, including several mud layers, before it can reach the water table. Investigation of the wadi aquifer using field observation, geological characterization, water-level monitoring, geophysical profiles, and a hypothetical model suggests a critical water level has been reached that affects the recharge of the aquifer. The wetted front can no longer reach the water table due to the water uptake in the wetting process, downstream deflection by the clay layers, and re-emergence of water at the surface with subsequent direct and diffusive evaporative loss, and likely uptake by deep-rooted acacia trees. In many areas of the wadi system, recharge can now occur only along the channel perimeter via fractured rocks that are in direct horizontal hydraulic connection to the permeable beds above and below the water table.

  14. Vulnerability of recently recharged groundwater in principal aquifers of the United States to nitrate contamination

    Science.gov (United States)

    Gurdak, Jason J.; Qi, Sharon L.

    2012-01-01

    Recently recharged water (defined here as interactions of natural and anthropogenic controlling factors that influence nitrate occurrence in recently recharged groundwater is critical to support best management and policy decisions that are often made at the aquifer to subaquifer scale. New logistic regression models were developed using data from the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program and National Water Information System for 17 principal aquifers of the U.S. to identify important source, transport, and attenuation factors that control nonpoint source nitrate concentrations greater than relative background levels in recently recharged groundwater and were used to predict the probability of detecting elevated nitrate in areas beyond the sampling network. Results indicate that dissolved oxygen, crops and irrigated cropland, fertilizer application, seasonally high water table, and soil properties that affect infiltration and denitrification are among the most important factors in predicting elevated nitrate concentrations. Important differences in controlling factors and spatial predictions were identified in the principal aquifer and national-scale models and support the conclusion that similar spatial scales are needed between informed groundwater management and model development.

  15. A rechargeable Na–CO 2 /O 2 battery enabled by stable nanoparticle hybrid electrolytes

    KAUST Repository

    Xu, Shaomao

    2014-09-10

    © the Partner Organisations 2014. We report on rechargeable batteries that use metallic sodium as the anode, a mixture of CO2 and O2 as the active material in the cathode, and an organic-inorganic hybrid liquid as electrolyte. The batteries are attractive among energy storage technologies because they provide a mechanism for simultaneously capturing CO2 emissions while generating electrical energy. Through in and ex situ chemical analysis of the cathode we show that NaHCO3 is the principal discharge product, and that its relative instability permits cell recharging. By means of differential electrochemical mass spectrometry (DEMS) based on 12C and 13C we further show that addition of as little as 10% of 1-methyl-3-propylimidazolium bis(trifluoromethanesulfone)imide ionic liquid tethered to SiO2 nanoparticles extends the high-voltage stability of the electrolyte by at least 1 V, allowing recharge of the Na-CO2/O2 cells. This journal is

  16. Maximum Data Collection Rate Routing Protocol Based on Topology Control for Rechargeable Wireless Sensor Networks.

    Science.gov (United States)

    Lin, Haifeng; Bai, Di; Gao, Demin; Liu, Yunfei

    2016-07-30

    In Rechargeable Wireless Sensor Networks (R-WSNs), in order to achieve the maximum data collection rate it is critical that sensors operate in very low duty cycles because of the sporadic availability of energy. A sensor has to stay in a dormant state in most of the time in order to recharge the battery and use the energy prudently. In addition, a sensor cannot always conserve energy if a network is able to harvest excessive energy from the environment due to its limited storage capacity. Therefore, energy exploitation and energy saving have to be traded off depending on distinct application scenarios. Since higher data collection rate or maximum data collection rate is the ultimate objective for sensor deployment, surplus energy of a node can be utilized for strengthening packet delivery efficiency and improving the data generating rate in R-WSNs. In this work, we propose an algorithm based on data aggregation to compute an upper data generation rate by maximizing it as an optimization problem for a network, which is formulated as a linear programming problem. Subsequently, a dual problem by introducing Lagrange multipliers is constructed, and subgradient algorithms are used to solve it in a distributed manner. At the same time, a topology controlling scheme is adopted for improving the network's performance. Through extensive simulation and experiments, we demonstrate that our algorithm is efficient at maximizing the data collection rate in rechargeable wireless sensor networks.

  17. Performance of Zn rechargeable cells having Polypyrrole cathodes doped with surfactant anion

    Directory of Open Access Journals (Sweden)

    W.A.D.S. S Weerasinghe

    2015-12-01

    Full Text Available Currently there exists a very high demand for electrochemical energy storage devices such as rechargeable cells and super capacitors due to massive increase in the use of portable electronics. At the moment this demand is mainly supplied by Li based cells. However due to high cost, rapid reactivity and issues in disposal of Li attention has diverted on non Li based cells. Zn has been identified as a good candidate to replace Li. Even though several Zn based rechargeable cells were reported, less work has been carried out on cells with conducting polymer cathode based Zn cells. In this study, performance of Zn rechargeable cells fabricated with conducting polymer Polypyrrole(PPy doped with a surfactant anion is reported. PPy films were galvanostatically electro polymerized on to stainless steel disc and cells were assembled with a Polyvinylidenefluoride based gel polymer electrolyte having Zinc trifluoromethanesulfonate as the salt. Cells having different cathode thickness were fabricated and they were characterized using cyclic voltammetry, electrochemical impedance spectroscopy and continuous charge-discharge tests. Cells exhibit open circuit voltages between 0.9 -1.0 V. Cycling testes showed that cycleable capacity almost follow the thickness variation. Continuous charge-discharge tests revealed that the capacity decrement with the cycle number is higher in thinner films.

  18. Labile Organic Carbon in Recharge and its Impact on Groundwater Arsenic Concentrations in Bangladesh

    Science.gov (United States)

    Neumann, R. B.; Ashfaque, K. N.; Badruzzaman, A. M.; Ali, M.; Shoemaker, J. K.; Harvey, C. F.

    2009-12-01

    Researchers have puzzled over the origin of dissolved arsenic in the aquifers of the Ganges Delta since widespread arsenic poisoning from groundwater was publicized two decades ago. Previous work has concluded that biological oxidation of organic carbon drives geochemical transformations that mobilize arsenic from sediments; however, the source of the organic carbon that fuels these processes remains controversial. A combined hydrologic and biogeochemical analysis of a typical site in Bangladesh, where constructed ponds and groundwater-irrigated rice fields are the main sources of recharge, shows that only recharge through pond sediments provides the biologically degradable organic carbon that can drive arsenic mobilization. Numerical groundwater simulations as well as chemical and isotopic indicators suggest that contaminated groundwater originates from excavated ponds and that water originating from rice fields is low in arsenic. In fact, rice fields act as an arsenic sink. Irrigation moves arsenic-rich groundwater from the aquifers and deposits it on the rice fields. Most of the deposited arsenic does not return to the aquifers; it is sorbed by the field’s surface soil and bunds, and is swept away in the monsoon floods. The findings indicate that patterns of arsenic contamination in the shallow aquifer are due to recharge-source variation and complex three-dimensional flow.

  19. Fluoride release and recharge from different materials used as fissure sealants.

    Science.gov (United States)

    Bayrak, Sule; Tunc, Emine Sen; Aksoy, Abdurrahman; Ertas, Ertan; Guvenc, Dilek; Ozer, Sezin

    2010-07-01

    Fluoride release/recharge properties of fissure sealants are important for their long-term inhibition of caries. This study was conducted to examine the relationship between fluoride release and recharge of pit-and-fissure sealants. Specimens were prepared from 5 different sealant materials: Fissurit F, a conventional resin; Fuji VII, a glass-ionomer cement (GIC); Fuji II LC, a resin-modified GIC; Ionosit, a polyacid-modified composite resin (PMRC); and Aelite Flo, a flowable composite resin. Specimens stored in a polyethylene test tube containing 5.0 ml ultrapure water. On day 21, specimens were exposed to 1.23% APF gel. Fluoride release was measured using a fluoride-specific ion electrode at 1-7, 14, 21, 22, 28, 35 and 42 days. The glass-ionomer based sealants Fuji VII and Fuji II LC had significantly higher fluoride release than the other materials at all times tested (Psealants were shown to have higher initial fluoride release as well as higher fluoride recharge capacity than other sealants.

  20. Compressive strength, surface roughness, fluoride release and recharge of four new fluoride-releasing fissure sealants.

    Science.gov (United States)

    Kavaloglu Cildir, Sule; Sandalli, Nuket

    2007-05-01

    The aim of this study was to investigate the compressive strength and surface roughness of two glass ionomer cements and two resin-based fissure sealants before and after fluoride release and recharge. Twenty-one specimens were prepared and divided into three groups for each material. First group was loaded in compression until failure. Fluoride released was measured from the remaining specimens, and then the second group of seven specimens was loaded at 28th day. The remaining seven specimens were exposed to 0.05% NaF solution and 1.23% APF gel. Fluoride amount was measured, and the last group was loaded at 70th day. Surface roughness measurement of five more disk-shaped specimens from each material was also carried out. After exposure to APF gel, all materials were recharged. At the end of experimental period, it was found that surface roughness increased, whereas compressive strength decreased, over time. In conclusion, fluoride-releasing fissure sealants could act as show, rechargeable fluoride release systems. However, if a fissure sealant exhibited high fluoride release, it had inferior mechanical properties.