WorldWideScience

Sample records for groundwater restoration systems

  1. Technical framework for groundwater restoration

    International Nuclear Information System (INIS)

    1991-04-01

    This document provides the technical framework for groundwater restoration under Phase II of the Uranium Mill Tailings Remedial Action (UMTRA) Project. A preliminary management plan for Phase II has been set forth in a companion document titled ''Preplanning Guidance Document for Groundwater Restoration''. General principles of site characterization for groundwater restoration, restoration methods, and treatment are discussed in this document to provide an overview of standard technical approaches to groundwater restoration

  2. Technical approach to groundwater restoration

    International Nuclear Information System (INIS)

    1993-01-01

    The Technical Approach to Groundwater Restoration (TAGR) provides general technical guidance to implement the groundwater restoration phase of the Uranium Mill Tailings Remedial Action (UMTRA) Project. The TAGR includes a brief overview of the surface remediation and groundwater restoration phases of the UMTRA Project and describes the regulatory requirements, the National Environmental Policy Act (NEPA) process, and regulatory compliance. A section on program strategy discusses program optimization, the role of risk assessment, the observational approach, strategies for meeting groundwater cleanup standards, and remedial action decision-making. A section on data requirements for groundwater restoration evaluates the data quality objectives (DQO) and minimum data required to implement the options and comply with the standards. A section on sits implementation explores the development of a conceptual site model, approaches to site characterization, development of remedial action alternatives, selection of the groundwater restoration method, and remedial design and implementation in the context of site-specific documentation in the site observational work plan (SOWP) and the remedial action plan (RAP). Finally, the TAGR elaborates on groundwater monitoring necessary to evaluate compliance with the groundwater cleanup standards and protection of human health and the environment, and outlines licensing procedures

  3. Nitrate removal in a restored riparian groundwater system: functioning and importance of individual riparian zones

    Directory of Open Access Journals (Sweden)

    S. Peter

    2012-11-01

    Full Text Available For the design and the assessment of river restoration projects, it is important to know to what extent the elimination of reactive nitrogen (N can be improved in the riparian groundwater. We investigated the effectiveness of different riparian zones, characterized by a riparian vegetation succession, for nitrate (NO3 removal from infiltrating river water in a restored and a still channelized section of the river Thur, Switzerland. Functional genes of denitrification (nirS and nosZ were relatively abundant in groundwater from willow bush and mixed forest dominated zones, where oxygen concentrations remained low compared to the main channel and other riparian zones. After flood events, a substantial decline in NO3 concentration (> 50% was observed in the willow bush zone but not in the other riparian zones closer to the river. In addition, the characteristic enrichment of 15N and 18O in the residual NO3 pool (by up to 22‰ for δ15N and up to 12‰ for δ18O provides qualitative evidence that the willow bush and forest zones were sites of active denitrification and, to a lesser extent, NO3 removal by plant uptake. Particularly in the willow bush zone during a period of water table elevation after a flooding event, substantial input of organic carbon into the groundwater occurred, thereby fostering post-flood denitrification activity that reduced NO3 concentration with a rate of ~21 μmol N l−1 d−1. Nitrogen removal in the forest zone was not sensitive to flood pulses, and overall NO3 removal rates were lower (~6 μmol l−1 d−1. Hence, discharge-modulated vegetation–soil–groundwater coupling was found to be a key driver for riparian NO3 removal. We estimated that

  4. Monitoring effects of river restoration on groundwater with radon

    International Nuclear Information System (INIS)

    Hoehn, Eduard

    2007-01-01

    The restoration of the perialpine river Toess in a floodplain of northern Switzerland (Linsental) included the removal of bank reinforcements and tracer studies in the river and in oberservation wells of the adjacent alluvial groundwater. The river water is continuously recharging the aquifer system and the groundwater is used extensively as drinking water. Radon activity concentrations of freshly infiltrated groundwater are interpreted as radon groundwater age between the river and a well. A first flood after the restoration operations resulted in a widening of the river bed and in a reduction of the flow distance to the wells. Sixteen days after a second flood, the results of radon measurements were compared with those from before the restoration. The radon age of the groundwater between the river and the wells decreased, probably as a result of the reduction of the flow distances. Concentrations of autochthonous and coliform bacteria increased after the restoration operation and even more one day after the first flood. Thus the findings on the bacteria corroborate the interpretation of the radon concentrations. The restoration has not yet reduced the quality of the groundwater, which is pumped for drinking water. The study is contributing to the solution of land-use conflicts between river restoration and the supply of drinking water from the alluvial groundwater. (orig.) [de

  5. Hoe Creek groundwater restoration, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Renk, R.R.; Crader, S.E.; Lindblom, S.R.; Covell, J.R.

    1990-01-01

    During the summer of 1989, approximately 6.5 million gallons of contaminated groundwater were pumped from 23 wells at the Hoe Creek underground coal gasification site, near Gillette, Wyoming. The organic contaminants were removed using activated carbon before the water was sprayed on 15.4 acres at the sites. Approximately 2647 g (5.8 lb) of phenols and 10,714 g (23.6 lb) of benzene were removed from the site aquifers. Phenols, benzene, toluene, ethylbenzene, and naphthalene concentrations were measured in 43 wells. Benzene is the only contaminant at the site exceeds the federal standard for drinking water (5 {mu}g/L). Benzene leaches into the groundwater and is slow to biologically degrade; therefore, the benzene concentration has remained high in the groundwater at the site. The pumping operation affected groundwater elevations across the entire 80-acre site. The water levels rebounded quickly when the pumping operation was stopped on October 1, 1989. Removing contaminated groundwater by pumping is not an effective way to clean up the site because the continuous release of benzene from coal tars is slow. Benzene will continue to leach of the tars for a long time unless its source is removed or the leaching rate retarded through mitigation techniques. The application of the treated groundwater to the surface stimulated plant growth. No adverse effects were noted or recorded from some 60 soil samples taken from twenty locations in the spray field area. 20 refs., 52 figs., 8 tabs.

  6. Impact of river restoration on groundwater - surface water - interactions

    Science.gov (United States)

    Kurth, Anne-Marie; Schirmer, Mario

    2014-05-01

    Sensing (DTS), a fibre optical method for temperature determination over long distances (Selker et al., 2006). Thermal signatures were determined in a small urban stream before and after restoration and compared to streams in natural and near-natural settings. BWG BUNDESAMT FÜR WASSER UND GEOLOGIE, 2003. Die Geschichte des Hochwasserschutzes in der Schweiz. Bericht des BWG, Serie Wasser. Biel. 208 p. EA ENVIRONMENT AGENCY (UK), 2009. The Hyporheic Handbook: A handbook on the groundwater-surface water interface and hyporheic zone for environment managers. Bristol. 280 p. ANDREA, F., GSCHÖPF, C., BLASCHKE, A.P., WEIGELHOFER, G., AND RECKENDORFER, W., 2012. Ecological niche models for the evaluation of management options in urban floodplain - conservation vs. restoration purposes. Environ. Sci. Policy, http://dx.doi.org/10.1016/j.envsci.2012.08.011. PALMER, M.A., BERNHARDT, E.S., ALLAN, J.D., LAKE, P.S., ALEXANDER, G., BROOKS, S., CARR, J., CLAYTON, S., DAHM, C.N., FOLLSTAD SHAH, J., GALAT, D.L., LOSS, S.G., GOODWIN, P., HART, D.D., HASSETT, B., JENKINSON, R., KONDOLF, G.M., LAVE, R., MEYER, J.L., O`DONNELL, T.K., PAGANO, L. AND SUDDUTH, E., 2005. Standards for ecologically successful river restoration. Journal of Applied Ecology, 42, pp. 208 - 217. DOI 10.1111/j.1365-2664.2005.01004.x. WORTLEY, L., HERO, J-M., HOWES, M., 2013. Evaluating Ecological Restoration Success: A Review of the Literature. Restoration Ecology, 21 (5), pp. 537 - 543. DOI 10.1111/rec.12028. SELKER, J.S., THEVENAZ, L., HUWALD, H., MALLET, A., LUXEMBURG, W., VAN DE GIESEN, N., STEJSKAL, M., ZEMAN, J., WESTHOFF, M., AND PARLANGE, M.B., 2006. Distributed fibre-optic temperature sensing for hydrologic systems. Water Resources Research, 42(12), W12202.

  7. Resource impact evaluation of in-situ uranium groundwater restoration

    International Nuclear Information System (INIS)

    Charbeneau, R.J.; Rohlich, G.A.

    1981-11-01

    The purpose of this study was to determine the impact of restoration on the groundwater following in-situ uranium solution mining in South Texas. Restoration is necessary in order to reduce the amounts of undesired chemical constituents left in solution after mining operations have ceased, and thus return the groundwater to a quality consistent with pre-mining use and potential use. Various restoration strategies have been proposed and are discussed. Of interest are the hydrologic, environmental, social, and economic impacts of these restoration alternatives. Much of the discussion concerning groundwater restoration is based on the use of an ammonium carbonate-bicarbonate leach solution in the mining process. This has been the principal leach solution used during the early period of mining in South Texas. Recently, because of apparent difficulties in restoring ammonium to proposed or required levels, many of the companies have changed to the use of other leach solutions. Because little is known about restoration with these other leach solutions they have not been specifically addressed in this report. Likewise, we have not addressed the question of the fate of heavy metals. Following a summary of the development of South Texas in-situ mining in Chapter Two, Chapter Three describes the surface and groundwater resources of the uranium mining district. Chapter Four addresses the economics of water use, and Chapter Five is concerned with regulation of the in-situ uranium industry in Texas. A discussion of groundwater restoration alternatives and impacts is presented in Chapter Six. Chapter Seven contains a summary and a discussion, and conclusions derived from this study. Two case histories are presented in Appendices A and B

  8. Environmental restoration: Integrating hydraulic control of groundwater, innovative contaminant removal technologies and wetlands restoration--A case study at SRS

    International Nuclear Information System (INIS)

    Lewis, C.M.; Serkiz, S.M.; Adams, J.; Welty, M.

    1992-01-01

    The groundwater remediation program at the F and H Seepage Basins, Savannah River Sits (SRS) is a case study of the integration of various environmental restoration technologies at a single waste site. Hydraulic control measures are being designed to mitigate the discharge of groundwater plumes to surface water. One of the primary constituents of the plumes is tritium. An extraction and reinjection scenario is being designed to keep the tritium in circulation in the shallow groundwater, until it can naturally decay. This will be accomplished by extracting groundwater downgradient of the waste sites, treatment, and reinjection of the tritiated water into the water table upgradient of the basins. Innovative in-situ technologies, including electrolytic migration, are being field tested at the site to augment the pump-treat-reinject system. The in-situ technologies target removal of contaminants which are relatively immobile, yet represent long term risks to human health and the environment. Wetland restoration is an integral part of the F and H remediation program. Both in-situ treatment of the groundwater discharging the wetlands to adjust the pH, and replacement of water loss due to the groundwater extraction program ar being considered. Toxicity studies indicate that drought and the effects of low pH groundwater discharge have been factors in observed tree mortality in wetlands near the waste sites

  9. Groundwater restoration of in-situ uranium mines

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    In-situ leaching is a relatively new uranium production technology that is expected to account for a growing share of future output. Depending upon the leaching solution used, the process may have considerable impact on the ground water. Since restoration of ground water quality is required in most countries and since this restoration is by far the most costly aspect of reclamation of an in-situ mine, it is necessary to utilize a process that lends itself both to the efficiency of the leaching process and the restoration process. This article examines a number of techniques that may be used in the restoration efforts. These include: (1) groundwater sweep, (2) reverse osmosis, (3) chemical restoration, and (4) electrodialysis. The article also discusses disposal of the excess fluids used in the restoration process

  10. Groundwater protection plan for the Environmental Restoration Disposal Facility

    International Nuclear Information System (INIS)

    Weekes, D.C.; Jaeger, G.K.; McMahon, W.J.; Ford, B.H.

    1996-01-01

    This document is the groundwater protection plan for the Environmental Restoration Disposal Facility (ERDF) Project. This plan is prepared based on the assumption that the ERDF will receive waste containing hazardous/dangerous constituents, radioactive constituents, and combinations of both. The purpose of this plan is to establish a groundwater monitoring program that (1) meets the intent of the applicable or relevant and appropriate requirements, (2) documents baseline groundwater conditions, (3) monitors those conditions for change, and (4) allows for modifications to groundwater sampling if required by the leachate management program. Groundwater samples indicate the occurrence of preexisting groundwater contamination in the uppermost unconfined aquifer below the ERDF Project site, as a result of past waste-water discharges in the 200 West Area. Therefore, it is necessary for the ERDF to establish baseline groundwater quality conditions and to monitor changes in the baseline over time. The groundwater monitoring program presented in this plan will provide the means to assess onsite and offsite impacts to the groundwater. In addition, a separate leachate management program will provide an indication of whether the liners are performing within design standards

  11. Wetland Restoration Response Analysis using MODIS and Groundwater Data

    Directory of Open Access Journals (Sweden)

    Michael McClain

    2007-09-01

    Full Text Available Vegetation cover and groundwater level changes over the period of restorationare the two most important indicators of the level of success in wetland ecohydrologicalrestoration. As a result of the regular presence of water and dense vegetation, the highestevapotranspiration (latent heat rates usually occur within wetlands. Vegetation cover andevapotranspiration of large areas of restoration like that of Kissimmee River basin, SouthFlorida will be best estimated using remote sensing technique than point measurements.Kissimmee River basin has been the area of ecological restoration for some years. Thecurrent ecohydrological restoration activities were evaluated through fractional vegetationcover (FVC changes and latent heat flux using Moderate Resolution ImagingSpectroradiometer (MODIS data. Groundwater level data were also analyzed for selectedeight groundwater monitoring wells in the basin. Results have shown that the averagefractional vegetation cover and latent heat along 10 km buffer of Kissimmee River betweenLake Kissimmee and Lake Okeechobee was higher in 2004 than in 2000. It is evident thatover the 5-year period of time, vegetated and areas covered with wetlands have increasedsignificantly especially along the restoration corridor. Analysis of groundwater level data(2000-2004 from eight monitoring wells showed that, the average monthly level ofgroundwater was increased by 20 cm and 34 cm between 2000 and 2004, and 2000 and2003, respectively. This change was more evident for wells along the river.

  12. The effectiveness of groundwater pumping as a restoration technology

    International Nuclear Information System (INIS)

    Doty, C.B.; Travis, C.C.

    1991-05-01

    An in-depth analysis of the effectiveness of pumping groundwater for aquifer restoration was conducted based on: (1) performance records for 16 sites where pumping with the objective of aquifer restoration has been implemented for periods of 2 to 12 years, and (2) recent theoretical and modeling studies. The reduction of aquifer concentrations is the primary indicator of effectiveness of groundwater extraction. However, other indicators of effectiveness such as plume containment, mass reduction, and achievement of specific cleanup goals were also components of the evaluation. Based on our review of performance records and recent theoretical studies, the following can be concluded regarding the use of groundwater pumping for aquifer restoration: (1) Pumping is effective for contaminant mass reduction, plume containment and extraction of groundwater for point-of-use treatment. Its use for attaining these objectives should be encouraged. (2) Groundwater pumping is ineffective for restoring aquifers to health-based levels. This reality needs to be explicitly recognized by regulators. (3) The primary contributors to the ineffectiveness of pumping in meeting cleanup goals are the time-dependent decrease in the rate of desorption of contaminants from contaminated soils and the existence of immobile contaminants either in the non-aqueous phase or trapped in zones of low permeability. (4) Remedial time frames of 2 years to 30 years were predicted at the sites reviewed. Regulators currently maintain that 20 to 40 years may be needed to reach health-based cleanup goals. However, recent modeling studies estimate pump and treat time frames of 100 to 1000 years. 22 refs., 5 figs., 4 tabs

  13. Groundwater restoration with in situ uranium leach mining

    International Nuclear Information System (INIS)

    Charbeneau, R.J.

    1984-01-01

    In situ leach mining of uranium has developed into a major mining technology. Since 1975, when the first commercial mine was licensed in the United States, the percentage or uranium produced by in situ mining has steadily grown from 0.6 to 10 percent in 1980. Part of the reason for this growth is that in situ mining offers less initial capital investment, shorter start-up times, greater safety, and less labor than conventional mining methods. There is little disturbance of the surface terrain or surface waters, no mill tailings piles, and no large open pits, but in situ leaching mining does have environmental disadvantages. During the mining, large amounts of ground water are cirulated and there is some withdrawal from an area where aquifers constitute a major portion of the water supply for other purposes. When an ammonia-based leach system is used, the ammonium ion is introduced into an area where cation exchange on clays (and some production of nitrate) may occur. Also, injection of an oxidant with the leach solution causes valence and phase changes of indigenous elements such as As, Cu, Fe, Mo, Se, S, and V as well as U. Furthermore, the surrounding ground water can become contaminated by escape of the leach solution from the mining zone. This chapter presents an overview of the in situ mining technology, including uranium deposition, mining techniques, and ground water restoration alternatives. The latter part of the chapter covers the situation in South Texas. Economics and development of the industry, groundwater resources, regulation, and restoration activities are also reviewed

  14. Performance assessment techniques for groundwater recovery and treatment systems

    Energy Technology Data Exchange (ETDEWEB)

    Kirkpatrick, G.L. [Environmental Resources Management, Inc., Exton, PA (United States)

    1993-03-01

    Groundwater recovery and treatment (pump and treat systems) continue to be the most commonly selected remedial technology for groundwater restoration and protection programs at hazardous waste sites and RCRA facilities nationwide. Implementing a typical groundwater recovery and treatment system includes the initial assessment of groundwater quality, characterizing aquifer hydrodynamics, recovery system design, system installation, testing, permitting, and operation and maintenance. This paper focuses on methods used to assess the long-term efficiency of a pump and treat system. Regulatory agencies and industry alike are sensitive to the need for accurate assessment of the performance and success of groundwater recovery systems for contaminant plume abatement and aquifer restoration. Several assessment methods are available to measure the long-term performance of a groundwater recovery system. This paper presents six assessment techniques: degree of compliance with regulatory agency agreement (Consent Order of Record of Decision), hydraulic demonstration of system performance, contaminant mass recovery calculation, system design and performance comparison, statistical evaluation of groundwater quality and preferably, integration of the assessment methods. Applying specific recovery system assessment methods depends upon the type, amount, and quality of data available. Use of an integrated approach is encouraged to evaluate the success of a groundwater recovery and treatment system. The methods presented in this paper are for engineers and corporate management to use when discussing the effectiveness of groundwater remediation systems with their environmental consultant. In addition, an independent (third party) system evaluation is recommended to be sure that a recovery system operates efficiently and with minimum expense.

  15. Calculation of pollutant removal during groundwater restoration with adsorption and ion exchange

    International Nuclear Information System (INIS)

    Charbeneau, R.J.

    1982-01-01

    A technique is presented for calculating pollutant removal rates during groundwater restoration processes. The hydraulic information required by the method is obtained from the conservative tracer breakthrough curve for a flow system. The influence of adsorption and ion exchange chemistry on species transport is included through application of the method of characteristics. The combined result gives the effluent concentration at a production well as a function of time during a restoration project. The method is applicable for any well pattern and its economy is such that a pencil and paper calculation will suffice for yielding quantitative answers for complex flow problems. The method is applied to calculate ammonium removal rates for site restoration by recirculation with chemical sweeps following in situ leach mining of uranium

  16. Analysis of groundwater criteria and recent restoration attempts after in situ uranium leaching. Open file report

    International Nuclear Information System (INIS)

    Buma, G.; Johnson, P.H.; Bienek, G.K.; Watson, C.G.; Noyes, H.J.

    1981-10-01

    Groundwater restoration is an important aspect of in situ uranium leaching. Information on the effectiveness of the current technology, costs, and the current State and Federal Government permitting regulations is of vital importance to in situ leach operators and firms considering in situ leaching. This study describes (1) all recent restoration attempts at commercial in situ leaching operations, (2) restoration costs reported by the industry, (3) empirical equations that predict the amount of groundwater flushing required to meet the current restoration criteria, and (4) in situ uranium permit requirements for the States of Texas, Wyoming, New Mexico, Utah, Montana, Colorado, and South Dakota, and Federal requirements

  17. Plant traits in response to raising groundwater levels in wetland restoration : evidence from three case studies

    NARCIS (Netherlands)

    Bodegom, P.M. van; Grootjans, A.P.; Sorrell, B.K.; Bekker, R.M.; Bakker, C.; Ozinga, W.A.; Middleton, B.

    Question: Is raising groundwater tables successful as a wetland restoration strategy? Location: Kennemer dunes, The Netherlands; Moksloot dunes, The Netherlands and Bullock Creek fen, New Zealand. Methods: Generalizations were made by analysing soil dynamics and the responsiveness of integrative

  18. Plant traits in response to raising groundwater levels in wetland restoration: evidence from three case studies

    NARCIS (Netherlands)

    Bodegom, van P.M.; Grootjans, A.P.; Sorrell, B.K.; Bekker, R.M.; Bakker, C.; Ozinga, W.A.

    2006-01-01

    Question: Is raising groundwater tables successful as a wetland restoration strategy? Location: Kennemer dunes, The Netherlands; Moksloot dunes, The Netherlands and Bullock Creek fen, New Zealand. Methods: Generalizations were made by analysing soil dynamics and the responsiveness of integrative

  19. Description of work for routine groundwater sampling at the Environmental Restoration Disposal Facility

    International Nuclear Information System (INIS)

    Ford, B.H.

    1996-09-01

    This document provides a description of work and field implementation guidance for routine (post-baseline) groundwater monitoring sampling program at the Environmental Restoration Disposal Facility. The purpose of this program is to (1) meet the intent of the applicable or relevant and appropriate requirements; (2) document baseline groundwater conditions; (3) monitor those conditions for change; and (4) allow for modifications to groundwater sampling if required by the leachate management program

  20. Technical considerations for the implementation of subsurface microbial barriers for restoration of groundwater at UMTRA sites

    International Nuclear Information System (INIS)

    Tucker, M.D.

    1996-01-01

    The Uranium Mill Tailings Remediation Action (UMTRA) Program is responsible for the assessment and remedial action at the 24 former uranium mill tailings sites located in the United States. The surface remediation phase, which has primarily focused on containment and stabilization of the abandoned uranium mill tailings piles, is nearing completion. Attention has now turned to the groundwater restoration phase. One alternative under consideration for groundwater restoration at UMTRA sites is the use of in-situ permeable reactive subsurface barriers. In this type of a system, contaminated groundwater will be allowed to flow naturally through a barrier filled with material which will remove hazardous constituents from the water by physical, chemical or microbial processes while allowing passage of the pore water. The subject of this report is a reactive barrier which would remove uranium and other contaminants of concern from groundwater by microbial action (i.e., a microbial barrier). The purpose of this report is to assess the current state of this technology and to determine issues that must be addressed in order to use this technology at UMTRA sites. The report focuses on six contaminants of concern at UMTRA sites including uranium, arsenic, selenium, molybdenum, cadmium and chromium. In the first section of this report, the fundamental chemical and biological processes that must occur in a microbial barrier to control the migration of contaminants are described. The second section contains a literature review of research which has been conducted on the use of microorganisms to immobilize heavy metals. The third section addresses areas which need further development before a microbial barrier can be implemented at an UMTRA site

  1. Technical considerations for the implementation of subsurface microbial barriers for restoration of groundwater at UMTRA sites

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, M.D.

    1996-01-01

    The Uranium Mill Tailings Remediation Action (UMTRA) Program is responsible for the assessment and remedial action at the 24 former uranium mill tailings sites located in the United States. The surface remediation phase, which has primarily focused on containment and stabilization of the abandoned uranium mill tailings piles, is nearing completion. Attention has now turned to the groundwater restoration phase. One alternative under consideration for groundwater restoration at UMTRA sites is the use of in-situ permeable reactive subsurface barriers. In this type of a system, contaminated groundwater will be allowed to flow naturally through a barrier filled with material which will remove hazardous constituents from the water by physical, chemical or microbial processes while allowing passage of the pore water. The subject of this report is a reactive barrier which would remove uranium and other contaminants of concern from groundwater by microbial action (i.e., a microbial barrier). The purpose of this report is to assess the current state of this technology and to determine issues that must be addressed in order to use this technology at UMTRA sites. The report focuses on six contaminants of concern at UMTRA sites including uranium, arsenic, selenium, molybdenum, cadmium and chromium. In the first section of this report, the fundamental chemical and biological processes that must occur in a microbial barrier to control the migration of contaminants are described. The second section contains a literature review of research which has been conducted on the use of microorganisms to immobilize heavy metals. The third section addresses areas which need further development before a microbial barrier can be implemented at an UMTRA site.

  2. Intellectual system for images restoration

    Science.gov (United States)

    Mardare, Igor

    2005-02-01

    Intelligence systems on basis of artificial neural networks and associative memory allow to solve effectively problems of recognition and restoration of images. However, within analytical technologies there are no dominating approaches of deciding of intellectual problems. Choice of the best technology depends on nature of problem, features of objects, volume of represented information about the object, number of classes of objects, etc. It is required to determine opportunities, preconditions and field of application of neural networks and associative memory for decision of problem of restoration of images and to use their supplementary benefits for further development of intelligence systems.

  3. Planning risk communication for UMTRA project groundwater restoration

    Energy Technology Data Exchange (ETDEWEB)

    Hundertmark, Charles [Jacobs Engineering Group Inc. and University of Phoenix (United States); Hoopes, Jack [Jacobs Engineering Group Inc. (United States); Flowers, Len [Roy F. Weston Company (United States); Jackson, David G [U.S. Department of Energy (United States)

    1992-07-01

    The U.S. Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project is entering a new phase in which groundwater contamination will become a growing focus as surface remedial action draws toward completion. Planning for risk communication associated with the groundwater project will be a major factor in the successful initiation of the program. (author)

  4. Planning risk communication for UMTRA project groundwater restoration

    International Nuclear Information System (INIS)

    Hundertmark, Charles; Hoopes, Jack; Flowers, Len; Jackson, David G.

    1992-01-01

    The U.S. Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project is entering a new phase in which groundwater contamination will become a growing focus as surface remedial action draws toward completion. Planning for risk communication associated with the groundwater project will be a major factor in the successful initiation of the program. (author)

  5. Monitoring effects of river restoration on groundwater with radon; Ueberwachung der Auswirkungen von Flussaufweitungen auf das Grundwasser mittels Radon

    Energy Technology Data Exchange (ETDEWEB)

    Hoehn, Eduard [Eawag, Eidgenoessische Anstalt fuer Wasserversorgung, Abwasserreinigung und Gewaesserschutz, Duebendorf (Switzerland)

    2007-03-15

    The restoration of the perialpine river Toess in a floodplain of northern Switzerland (Linsental) included the removal of bank reinforcements and tracer studies in the river and in oberservation wells of the adjacent alluvial groundwater. The river water is continuously recharging the aquifer system and the groundwater is used extensively as drinking water. Radon activity concentrations of freshly infiltrated groundwater are interpreted as radon groundwater age between the river and a well. A first flood after the restoration operations resulted in a widening of the river bed and in a reduction of the flow distance to the wells. Sixteen days after a second flood, the results of radon measurements were compared with those from before the restoration. The radon age of the groundwater between the river and the wells decreased, probably as a result of the reduction of the flow distances. Concentrations of autochthonous and coliform bacteria increased after the restoration operation and even more one day after the first flood. Thus the findings on the bacteria corroborate the interpretation of the radon concentrations. The restoration has not yet reduced the quality of the groundwater, which is pumped for drinking water. The study is contributing to the solution of land-use conflicts between river restoration and the supply of drinking water from the alluvial groundwater. (orig.) [German] Die Renaturierung des voralpinen Flusses Toess in der Schotterebene des Linsentals (suedlich Winterthur, Nordschweiz) mit einer Befreiung von seinen Uferverbauungen gab Anlass zu Traceruntersuchungen im Fluss und im Grundwasser des kiessandigen Schotters. In diesem Gebiet infiltriert der Fluss ueberall und immer natuerlicherweise ins Grundwasser, welches stark als Trinkwasser genutzt wird. Radon-Aktivitaetskonzentrationen von frisch infiltriertem Grundwasser wurden interpretiert als Radon-Grundwasseralter fuer Strecken zwischen dem Fluss und Grundwasserbeobachtungsrohren. Nach einem

  6. Towards improved instrumentation for assessing river-groundwater interactions in a restored river corridor

    Directory of Open Access Journals (Sweden)

    P. Schneider

    2011-08-01

    Full Text Available River restoration projects have been launched over the last two decades to improve the ecological status and water quality of regulated rivers. As most restored rivers are not monitored at all, it is difficult to predict consequences of restoration projects or analyze why restorations fail or are successful. It is thus necessary to implement efficient field assessment strategies, for example by employing sensor networks that continuously measure physical parameters at high spatial and temporal resolution. This paper focuses on the design and implementation of an instrumentation strategy for monitoring changes in bank filtration, hydrological connectivity, groundwater travel time and quality due to river restoration. We specifically designed and instrumented a network of monitoring wells at the Thur River (NE Switzerland, which is partly restored and has been mainly channelized for more than 100 years. Our results show that bank filtration – especially in a restored section with alternating riverbed morphology – is variable in time and space. Consequently, our monitoring network has been adapted in response to that variability. Although not available at our test site, we consider long-term measurements – ideally initiated before and continued after restoration – as a fundamental step towards predicting consequences of river restoration for groundwater quality. As a result, process-based models could be adapted and evaluated using these types of high-resolution data sets.

  7. Recommendations for computer modeling codes to support the UMTRA groundwater restoration project

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, M.D. [Sandia National Labs., Albuquerque, NM (United States); Khan, M.A. [IT Corp., Albuquerque, NM (United States)

    1996-04-01

    The Uranium Mill Tailings Remediation Action (UMTRA) Project is responsible for the assessment and remedial action at the 24 former uranium mill tailings sites located in the US. The surface restoration phase, which includes containment and stabilization of the abandoned uranium mill tailings piles, has a specific termination date and is nearing completion. Therefore, attention has now turned to the groundwater restoration phase, which began in 1991. Regulated constituents in groundwater whose concentrations or activities exceed maximum contaminant levels (MCLs) or background levels at one or more sites include, but are not limited to, uranium, selenium, arsenic, molybdenum, nitrate, gross alpha, radium-226 and radium-228. The purpose of this report is to recommend computer codes that can be used to assist the UMTRA groundwater restoration effort. The report includes a survey of applicable codes in each of the following areas: (1) groundwater flow and contaminant transport modeling codes, (2) hydrogeochemical modeling codes, (3) pump and treat optimization codes, and (4) decision support tools. Following the survey of the applicable codes, specific codes that can best meet the needs of the UMTRA groundwater restoration program in each of the four areas are recommended.

  8. Recommendations for computer modeling codes to support the UMTRA groundwater restoration project

    International Nuclear Information System (INIS)

    Tucker, M.D.; Khan, M.A.

    1996-04-01

    The Uranium Mill Tailings Remediation Action (UMTRA) Project is responsible for the assessment and remedial action at the 24 former uranium mill tailings sites located in the US. The surface restoration phase, which includes containment and stabilization of the abandoned uranium mill tailings piles, has a specific termination date and is nearing completion. Therefore, attention has now turned to the groundwater restoration phase, which began in 1991. Regulated constituents in groundwater whose concentrations or activities exceed maximum contaminant levels (MCLs) or background levels at one or more sites include, but are not limited to, uranium, selenium, arsenic, molybdenum, nitrate, gross alpha, radium-226 and radium-228. The purpose of this report is to recommend computer codes that can be used to assist the UMTRA groundwater restoration effort. The report includes a survey of applicable codes in each of the following areas: (1) groundwater flow and contaminant transport modeling codes, (2) hydrogeochemical modeling codes, (3) pump and treat optimization codes, and (4) decision support tools. Following the survey of the applicable codes, specific codes that can best meet the needs of the UMTRA groundwater restoration program in each of the four areas are recommended

  9. Restoration of groundwater after solution mining at the Highland Uranium Project, Wyoming, USA

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, J. [Waste Technology Group, British Nuclear Fuels PLC, Risley, Warrington (United Kingdom); Huffman, L. [Power Resources Inc., Highland Uranium Mine, Glenrock, Wyoming (United States)

    2000-07-01

    The Highland Project, located in Converse County, Wyoming, has had a successful 11 year history of in-situ leach mining of Tertiary roll-front uranium deposits. The uranium ore is oxidized and solubilized by circulating native groundwater, containing additional dissolved O{sub 2} and CO{sub 2}, within confined fluvial aquifers at depths of 200 - 250 m. The changing chemistry of this groundwater during leaching is discussed, as are the various treatment techniques that have been used to restore this fluid at the end of mining. Examples are provided which demonstrate the varying effectiveness of each technique for the reduction of elevated concentrations of different groundwater parameters. The complications arising from the proximity of the earliest wellfields to abandoned, conventional mine workings, as well as unexpected side effects from each restoration method, have combined to make an interesting case history from this long established mining operation. (author)

  10. Power system restoration: planning and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hazarika, D. [Assam Engineering Coll., Dept. of Electrical Engineering, Assam (India); Sinha, A.K. [Inidan Inst. of Technology, Dept. of Electrical Engineering, Kharagpur (India)

    2003-03-01

    This paper describes a restoration guidance simulator, which allows power system operator/planner to simulate and plan restoration events in an interactive mode. The simulator provides a list of restoration events according to the priority based on some restoration rules and list of priority loads. It also provides in an interactive mode the list of events, which becomes possible as the system grows during restoration. Further, the selected event is validated through a load flow and other analytical tools to show the consequences of implementing the planned event. (Author)

  11. Groundwater restoration of uranium ISL mines in the United States

    International Nuclear Information System (INIS)

    Catchpole, G.; Kuchelka, R.

    1993-01-01

    Although the in-situ leach (ISL) mining of uranium in the US started in the 1960's, the real expansion of this form of mining, which is also called solution mining, took place in the early to mid 1970's in Texas. Some of the early test work used an acid lixiviant but it was soon recognized that, because of environmental considerations, the use of alkaline lixiviants would be preferable to the regulatory agencies and the public. In the past, the two types of alkaline based lixiviants used at US ISL mines were ammonia bicarbonate and sodium bicarbonate. A few ISL mines get by with just adding carbon dioxide to the well field solution. Ammonia bicarbonate is no longer being used today in the US because of the difficulties and expense of restoring the water quality to acceptable standards following mining. This paper briefly describes ISL mining principles and then details procedures and techniques used at USA ISL uranium mines to restore water quality in the mined aquifer. The basic elements are fairly constant but there can be considerable variation in type of water treatment equipment, methods of waste water disposal and use of chemical reducing agents. Three case histories are also presented

  12. Hydrological mediated denitrification in groundwater below a seasonal flooded restored riparian zone

    DEFF Research Database (Denmark)

    Jensen, Jannick Kolbjørn; Engesgaard, Peter; Johnsen, Anders R.

    2017-01-01

    nitrate removal in groundwater primarily by two mechanisms. First, by creating a stagnant flow zone beneath the flooded area thereby increasing the residence time and leaving more time for nitrate removal. Secondly, nitrate removal is increased by enhancing upward flow into the highly reactive organic......A restored riparian zone was characterized to understand the effects of flooding on subsurface hydrological flow paths and nitrate removal in groundwater. Field and laboratory investigations were combined with numerical modeling of dynamic flow and reactive nitrate transport. Flooding enhances...

  13. Nuclear plant requirements during power system restoration

    International Nuclear Information System (INIS)

    Adamski, G.; Jenkins, R.; Gill, P.

    1995-01-01

    This paper is one of a series presented on behalf of the System Operation Subcommittee with the intent of focusing industry attention on power system restoration issues. This paper discusses a number of nuclear power plant requirements that require special attention during power system restoration

  14. Regional ground-water system

    International Nuclear Information System (INIS)

    Long, J.

    1985-01-01

    The Containment and Isolation Working Group considered issues related to the postclosure behavior of repositories in crystalline rock. This working group was further divided into subgroups to consider the progress since the 1978 GAIN Symposium and identify research needs in the individual areas of regional ground-water flow, ground-water travel time, fractional release, and cumulative release. The analysis and findings of the Ground-Water Regime Subgroup are presented

  15. Designing an enhanced groundwater sample collection system

    International Nuclear Information System (INIS)

    Schalla, R.

    1994-10-01

    As part of an ongoing technical support mission to achieve excellence and efficiency in environmental restoration activities at the Laboratory for Energy and Health-Related Research (LEHR), Pacific Northwest Laboratory (PNL) provided guidance on the design and construction of monitoring wells and identified the most suitable type of groundwater sampling pump and accessories for monitoring wells. The goal was to utilize a monitoring well design that would allow for hydrologic testing and reduce turbidity to minimize the impact of sampling. The sampling results of the newly designed monitoring wells were clearly superior to those of the previously installed monitoring wells. The new wells exhibited reduced turbidity, in addition to improved access for instrumentation and hydrologic testing. The variable frequency submersible pump was selected as the best choice for obtaining groundwater samples. The literature references are listed at the end of this report. Despite some initial difficulties, the actual performance of the variable frequency, submersible pump and its accessories was effective in reducing sampling time and labor costs, and its ease of use was preferred over the previously used bladder pumps. The surface seals system, called the Dedicator, proved to be useful accessory to prevent surface contamination while providing easy access for water-level measurements and for connecting the pump. Cost savings resulted from the use of the pre-production pumps (beta units) donated by the manufacturer for the demonstration. However, larger savings resulted from shortened field time due to the ease in using the submersible pumps and the surface seal access system. Proper deployment of the monitoring wells also resulted in cost savings and ensured representative samples

  16. Geochemistry and the Understanding of Groundwater Systems

    Science.gov (United States)

    Glynn, P. D.; Plummer, L. N.; Weissmann, G. S.; Stute, M.

    2009-12-01

    Geochemical techniques and concepts have made major contributions to the understanding of groundwater systems. Advances continue to be made through (1) development of measurement and characterization techniques, (2) improvements in computer technology, networks and numerical modeling, (3) investigation of coupled geologic, hydrologic, geochemical and biologic processes, and (4) scaling of individual observations, processes or subsystem models into larger coherent model frameworks. Many applications benefit from progress in these areas, such as: (1) understanding paleoenvironments, in particular paleoclimate, through the use of groundwater archives, (2) assessing the sustainability (recharge and depletion) of groundwater resources, and (3) their vulnerability to contamination, (4) evaluating the capacity and consequences of subsurface waste isolation (e.g. geologic carbon sequestration, nuclear and chemical waste disposal), (5) assessing the potential for mitigation/transformation of anthropogenic contaminants in groundwater systems, and (6) understanding the effect of groundwater lag times in ecosystem-scale responses to natural events, land-use changes, human impacts, and remediation efforts. Obtaining “representative” groundwater samples is difficult and progress in obtaining “representative” samples, or interpreting them, requires new techniques in characterizing groundwater system heterogeneity. Better characterization and simulation of groundwater system heterogeneity (both physical and geochemical) is critical to interpreting the meaning of groundwater “ages”; to understanding and predicting groundwater flow, solute transport, and geochemical evolution; and to quantifying groundwater recharge and discharge processes. Research advances will also come from greater use and progress (1) in the application of environmental tracers to ground water dating and in the analysis of new geochemical tracers (e.g. compound specific isotopic analyses, noble gas

  17. Pickering Nuclear site wide groundwater monitoring system

    International Nuclear Information System (INIS)

    DeWilde, J.; Chin-Cheong, D.; Lledo, C.; Wootton, R.; Belanger, D.; Hansen, K.

    2001-01-01

    Ontario Power Generation Inc. (OPG) is continuing its efforts to understand the chemical and physical characteristics of the groundwater flow systems beneath the Pickering Nuclear Generating Station (PNGS). To this end, OPG constructed a site-wide Groundwater Monitoring System (GMS) at the PNGS to provide support to other ongoing environmental investigations and to provide a means to monitor current and future groundwater environmental issues. This paper will present the results of this work, including the development of a state-of-the-art data management system for storage and retrieval of environmental data for the site, which has applications for other power generation facilities. (author)

  18. Ecological restoration of groundwater-dependent vegetation in the arid Ejina Delta: evidences from satellite evapotranspiration

    Science.gov (United States)

    Kai, Lu; Garcia, Monica; Yu, Jingjie; Zhang, Yichi; Wang, Ping; Wang, Sheng; Liu, Xiao

    2017-04-01

    The ecological water conveyance project (EWCP) in the Ejina delta, a typical hyper-arid area of China, aimed to restore degraded phreatophytic ecosystems. We assessed the degree of ecosystem recovery using as an ecohydrological indicator a ratio between actual and potential evapotranspiration derived from MODIS since the beginning of the project in 2001. The selected indicator was the Temperature Vegetation Dryness Index (TVDI) which was validated with Eddy covariance (EC) data confirming its applicability to monitor groundwater dependent vegetation. The spatial analyses of the evapotranspiration ratio show drying trends (2000-2015) which are stronger and also cover larger extensions than the wetting trends. Thus, the condition of key riparian areas relying mostly on surface water improved since the project began. However, groundwater dependent ecosystems located in lower river Xihe reaches present drying trends. It seems that despite of the runoff supplemented by the EWCP project, there is nowadays more inequality in the access to water by groundwater dependent ecosystems in the Ejina Delta. The study shows that energy-evaporation indices, relying on radiometric satellite temperature like the TVDI, can detect degradation signals that otherwise might go undetected by NDVI analyses especially in arid regions, where vegetation indices are greatly affected by the soil background signals. Additionally, they can provide timely information to water managers on how much water to allocate for a sustainable restoration program.

  19. Groundwater restoration long beyond closure at the Homestake-Milan and United Nuclear-Church Rock uranium mill tailings piles, New Mexico, USA: full-scale programs requiring more than 20 years of active treatment

    International Nuclear Information System (INIS)

    Robinson, W.P.

    1998-01-01

    Since as early as 1975, groundwater contamination from New Mexico uranium mill tailings has been investigated with two sites -Homestake-Milan and United Nuclear-Church Rock -showing severe enough groundwater damage to merit listing on the US Environmental Protection Agency's (EPA) Superfund National Priority List -a nationwide list based on severity of pollution and water resource usefulness. These two sites provide valuable case studies for the first - 1950s -and second - 1970s -generations of uranium mill tailings facilities demonstrating the severity of contamination which ineffective control can allow and the challenge of full scale groundwater restoration. While the groundwater restoration at these sites began in the 1970s and 1980s, active treatment is anticipated into the 21st century. This paper summarizes the groundwater restoration programs at two of these sites - Homestake Mining Company's (HMC) Milan Mill (now called the ''Grants Project'') and United Nuclear Corporation's (UNC) Church Rock Mill. The two sites are summarized with respect to operations, groundwater impact, tailings disposal systems, hydrogeological characteristics of the site and affected areas, applicable standards, and remedial technology applied. This review provides a basis for initial comparisons with uranium mill tailings groundwater restoration challenges outside the USA. These sites provide an important benchmark the complexity of restoration at for large-scale uranium mill tailings sites. The longevity of the restoration efforts demonstrate the results of low-intensity responses to contamination upon detection and delayed enforcement actions. These ''witnesses'' to the value of effective pollution prevention in tailings design and full review and monitoring of tailings operations, have potential to be models of effective groundwater restoration. (orig.)

  20. Documentation of a groundwater flow model (SJRRPGW) for the San Joaquin River Restoration Program study area, California

    Science.gov (United States)

    Traum, Jonathan A.; Phillips, Steven P.; Bennett, George L.; Zamora, Celia; Metzger, Loren F.

    2014-01-01

    To better understand the potential effects of restoration flows on existing drainage problems, anticipated as a result of the San Joaquin River Restoration Program (SJRRP), the U.S. Geological Survey (USGS), in cooperation with the U.S. Bureau of Reclamation (Reclamation), developed a groundwater flow model (SJRRPGW) of the SJRRP study area that is within 5 miles of the San Joaquin River and adjacent bypass system from Friant Dam to the Merced River. The primary goal of the SJRRP is to reestablish the natural ecology of the river to a degree that restores salmon and other fish populations. Increased flows in the river, particularly during the spring salmon run, are a key component of the restoration effort. A potential consequence of these increased river flows is the exacerbation of existing irrigation drainage problems along a section of the river between Mendota and the confluence with the Merced River. Historically, this reach typically was underlain by a water table within 10 feet of the land surface, thus requiring careful irrigation management and (or) artificial drainage to maintain crop health. The SJRRPGW is designed to meet the short-term needs of the SJRRP; future versions of the model may incorporate potential enhancements, several of which are identified in this report. The SJRRPGW was constructed using the USGS groundwater flow model MODFLOW and was built on the framework of the USGS Central Valley Hydrologic Model (CVHM) within which the SJRRPGW model domain is embedded. The Farm Process (FMP2) was used to simulate the supply and demand components of irrigated agriculture. The Streamflow-Routing Package (SFR2) was used to simulate the streams and bypasses and their interaction with the aquifer system. The 1,300-square mile study area was subdivided into 0.25-mile by 0.25-mile cells. The sediment texture of the aquifer system, which was used to distribute hydraulic properties by model cell, was refined from that used in the CVHM to better represent

  1. 75 FR 71625 - System Restoration Reliability Standards

    Science.gov (United States)

    2010-11-24

    ... to start operating and delivering electric power without assistance from the electric system... and system restoration and reporting following disturbances. \\3\\ North American Electric Reliability... Reliability Standards for the Bulk-Power System and determined that the proposed requirements are necessary to...

  2. 76 FR 16277 - System Restoration Reliability Standards

    Science.gov (United States)

    2011-03-23

    ... electric system. Blackstart units are essential to restart generation and restore power to the grid in the... Standard EOP-007-0. \\2\\ Mandatory Reliability Standards for the Bulk-Power System, Order No. 693, 72 FR... = $5,894,624. Title: Mandatory Reliability Standards for the Bulk-Power System. Action: FERC 725A...

  3. Environmental Restoration Program Control Management System

    International Nuclear Information System (INIS)

    Duke, R.T.

    1992-01-01

    Environmental Restoration managers need to demonstrate that their programs are under control. Unlike most industrial programs, the public is heavily involved in Environmental Restoration activities. The public is demanding that the country prove that real progress is being made towards cleaning up the environment. A Program Control Management System can fill this need. It provides a structure for planning, work authorization, data accumulation, data analysis and change control. But it takes time to implement a control system and the public is losing its patience. This paper describes critical items essential to the quick development and implementation of a successful control system

  4. Successive use of vacuum-enhanced extraction, in situ chemical oxidation, bioaugmentation and mathematical modeling for the restoration of impacted soil and groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Morin, A.; Lauzon, J.M. [TechnoRem Inc., Laval, PQ (Canada)

    2007-07-01

    A leak from an active gasoline service station in northern Quebec was discussed. Leaking petroleum from an underground storage tank (UST) in June 2005 resulted in a 4,000 m{sup 2} light non-aqueous phase liquid (LNAPL) plume causing both soil and groundwater contamination. This presentation described the site, environmental issues, selected remedial technologies, worked performed and results. TechnoRem conducted laboratory and bench-scale testing to determine the optimal treatment products and conditions for mitigation. The LNAPL was recovered using vacuum-enhanced extraction (VEE). Chemical oxidation (CO) and bioaugmentation (BA) was also used to restore the site. The soil and groundwater targets for various parameters were tabulated for total petroleum hydrocarbons and BTEX (benzene, toluene, ethylbenzene and xylenes). It was noted that groundwater was flowing south towards a lake 100 metres downgradient. Schematics of the VEE, CO and BA equipment were presented along with several images of the design, installation, commission and operation of the systems. A total of 128 pumping/injection wells were used to sample soil, groundwater and LNAPL. In November 2006, soil analyses indicated that the total petroleum hydrocarbons and BTEX met the applicable criteria. The contaminated groundwater plume is now minor and in regression. Groundwater monitoring and supply of nutrients and oxygen will be performed for the coming years to allow for enhanced natural attenuation to mitigate the residual contaminants. tabs., figs.

  5. Continuous Long-Term Modeling of Shallow Groundwater-Surface Water Interaction: Implications for a Wet Prairie Restoration

    Science.gov (United States)

    Wijayarathne, D. B.; Gomezdelcampo, E.

    2017-12-01

    The existence of wet prairies is wholly dependent on the groundwater and surface water interaction. Any process that alters this interaction has a significant impact on the eco-hydrology of wet prairies. The Oak Openings Region (OOR) in Northwest Ohio supports globally rare wet prairie habitats and the precious few remaining have been drained by ditches, altering their natural flow and making them an unusually variable and artificial system. The Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model from the US Army Engineer Research and Development Center was used to assess the long-term impacts of land-use change on wet prairie restoration. This study is the first spatially explicit, continuous, long-term modeling approach for understanding the response of the shallow groundwater system of the OOR to human intervention, both positive and negative. The GSSHA model was calibrated using a 2-year weekly time series of water table elevations collected with an array of piezometers in the field. Basic statistical analysis indicates a good fit between observed and simulated water table elevations on a weekly level, though the model was run on an hourly time step and a pixel size of 10 m. Spatially-explicit results show that removal of a local ditch may not drastically change the amount of ponding in the area during spring storms, but large flooding over the entire area would occur if two other ditches are removed. This model is being used by The Nature Conservancy and Toledo Metroparks to develop different scenarios for prairie restoration that minimize its effect on local homeowners.

  6. Effects of road salts on groundwater and surface water dynamics of socium and chloride in an urban restored stream

    Science.gov (United States)

    Road salts are a growing environmental concern in urban watersheds. We examined groundwater (GW) and surface water (SW) dynamics of Na+ and Cl− in Minebank Run (MBR), an urban stream in Maryland, USA. We observed an increasing salinity trend in this restored stream. Current basef...

  7. Environmental Restoration Project - Systems Engineering Management Plan

    International Nuclear Information System (INIS)

    Anderson, T.D.

    1998-06-01

    This Environmental Restoration (ER) Project Systems Engineering Management Plan (SEMP) describes relevant Environmental Restoration Contractor (ERC) management processes and shows how they implement systems engineering. The objective of this SEMP is to explain and demonstrate how systems engineering is being approached and implemented in the ER Project. The application of systems engineering appropriate to the general nature and scope of the project is summarized in Section 2.0. The basic ER Project management approach is described in Section 3.0. The interrelation and integration of project practices and systems engineering are outlined in Section 4.0. Integration with sitewide systems engineering under the Project Hanford Management Contract is described in Section 5.0

  8. An early warning system for groundwater pollution based on the assessment of groundwater pollution risks.

    Science.gov (United States)

    Zhang, Weihong.; Zhao, Yongsheng; Hong, Mei; Guo, Xiaodong

    2009-04-01

    Groundwater pollution usually is complex and concealed, remediation of which is difficult, high cost, time-consuming, and ineffective. An early warning system for groundwater pollution is needed that detects groundwater quality problems and gets the information necessary to make sound decisions before massive groundwater quality degradation occurs. Groundwater pollution early warning were performed by considering comprehensively the current groundwater quality, groundwater quality varying trend and groundwater pollution risk . The map of the basic quality of the groundwater was obtained by fuzzy comprehensive evaluation or BP neural network evaluation. Based on multi-annual groundwater monitoring datasets, Water quality state in sometime of the future was forecasted using time-sequenced analyzing methods. Water quality varying trend was analyzed by Spearman's rank correlative coefficient.The relative risk map of groundwater pollution was estimated through a procedure that identifies, cell by cell,the values of three factors, that is inherent vulnerability, load risk of pollution source and contamination hazard. DRASTIC method was used to assess inherent vulnerability of aquifer. Load risk of pollution source was analyzed based on the potential of contamination and pollution degree. Assessment index of load risk of pollution source which involves the variety of pollution source, quantity of contaminants, releasing potential of pollutants, and distance were determined. The load risks of all sources considered by GIS overlay technology. Early warning model of groundwater pollution combined with ComGIS technology organically, the regional groundwater pollution early-warning information system was developed, and applied it into Qiqiha'er groundwater early warning. It can be used to evaluate current water quality, to forecast water quality changing trend, and to analyze space-time influencing range of groundwater quality by natural process and human activities. Keywords

  9. Advanced Protection & Service Restoration for FREEDM Systems

    Science.gov (United States)

    Singh, Urvir

    A smart electric power distribution system (FREEDM system) that incorporates DERs (Distributed Energy Resources), SSTs (Solid State Transformers - that can limit the fault current to two times of the rated current) & RSC (Reliable & Secure Communication) capabilities has been studied in this work in order to develop its appropriate protection & service restoration techniques. First, a solution is proposed that can make conventional protective devices be able to provide effective protection for FREEDM systems. Results show that although this scheme can provide required protection but it can be quite slow. Using the FREEDM system's communication capabilities, a communication assisted Overcurrent (O/C) protection scheme is proposed & results show that by using communication (blocking signals) very fast operating times are achieved thereby, mitigating the problem of conventional O/C scheme. Using the FREEDM System's DGI (Distributed Grid Intelligence) capability, an automated FLISR (Fault Location, Isolation & Service Restoration) scheme is proposed that is based on the concept of 'software agents' & uses lesser data (than conventional centralized approaches). Test results illustrated that this scheme is able to provide a global optimal system reconfiguration for service restoration.

  10. IDENTIFIABILITY VERSUS HETEROGENEITY IN GROUNDWATER MODELING SYSTEMS

    Directory of Open Access Journals (Sweden)

    A M BENALI

    2003-06-01

    Full Text Available Review of history matching of reservoirs parameters in groundwater flow raises the problem of identifiability of aquifer systems. Lack of identifiability means that there exists parameters to which the heads are insensitive. From the guidelines of the study of the homogeneous case, we inspect the identifiability of the distributed transmissivity field of heterogeneous groundwater aquifers. These are derived from multiple realizations of a random function Y = log T  whose probability distribution function is normal. We follow the identifiability of the autocorrelated block transmissivities through the measure of the sensitivity of the local derivatives DTh = (∂hi  ∕ ∂Tj computed for each sample of a population N (0; σY, αY. Results obtained from an analysis of Monte Carlo type suggest that the more a system is heterogeneous, the less it is identifiable.

  11. Evaluation of a multiport groundwater monitoring system

    International Nuclear Information System (INIS)

    Gilmore, T.J.; Hall, S.H.; Olsen, K.B.; Spane, F.A. Jr.

    1991-03-01

    In 1988 and 1989, Pacific Northwest Laboratory installed a multiport groundwater monitoring system in two wells on the Hanford Site: one near the 216-B-3 Pond in the center of the Hanford Site and one just north of the 300 Area near the Columbia River. The system was installed to provide the US Department of Energy with needed three-dimensional data on the vertical distribution of contaminants and hydraulic heads on the Hanford Site. This study evaluates the ability of the multiport system to obtain hydrogeologic data at multiple points vertically in a single borehole, and addresses the representativeness of the data. Data collected from the two wells indicate that the multiport system is well suited for groundwater monitoring networks requiring three-dimensional characterization of the hydrogeologic system. A network of these systems could provide valuable information on the hydrogeologic environment. However, the advantages of the multiport system diminish when the system is applied to long-term monitoring networks (30+ years) and to deeper wells (<300 ft). For shallow wells, the multiport system provides data in a cost-effective manner that would not be reasonably obtainable with the conventional methods currently in use at the Hanford Site. 17 refs., 28 figs., 6 tabs

  12. Revised conceptualization of the North China Basin groundwater flow system: Groundwater age, heat and flow simulations

    Science.gov (United States)

    Cao, Guoliang; Han, Dongmei; Currell, Matthew J.; Zheng, Chunmiao

    2016-09-01

    Groundwater flow in deep sedimentary basins results from complex evolution processes on geological timescales. Groundwater flow systems conceptualized according to topography and/or groundwater table configuration generally assume a near-equilibrium state with the modern landscape. However, the time to reach such a steady state, and more generally the timescales of groundwater flow system evolution are key considerations for large sedimentary basins. This is true in the North China Basin (NCB), which has been studied for many years due to its importance as a groundwater supply. Despite many years of study, there remain contradictions between the generally accepted conceptual model of regional flow, and environmental tracer data. We seek to reconcile these contractions by conducting simulations of groundwater flow, age and heat transport in a three dimensional model, using an alternative conceptual model, based on geological, thermal, isotope and historical data. We infer flow patterns under modern hydraulic conditions using this new model and present the theoretical maximum groundwater ages under such a flow regime. The model results show that in contrast to previously accepted conceptualizations, most groundwater is discharged in the vicinity of the break-in-slope of topography at the boundary between the piedmont and central plain. Groundwater discharge to the ocean is in contrast small, and in general there are low rates of active flow in the eastern parts of the basin below the central and coastal plain. This conceptualization is more compatible with geochemical and geothermal data than the previous model. Simulated maximum groundwater ages of ∼1 Myrs below the central and coastal plain indicate that residual groundwater may be retained in the deep parts of the basin since being recharged during the last glacial period or earlier. The groundwater flow system has therefore probably not reached a new equilibrium state with modern-day hydraulic conditions. The

  13. Ecosystem restoration: a systems approach to exotic plant control

    Science.gov (United States)

    Karl D. Smith

    1998-01-01

    Ecosystem restoration is a systems approach because it relates to all of the thousands of interrelated and interacting systems within the ecosystem. Ecosystem restoration also changes your role in the forest from observer to participant. Some of the goals of ecosystem restoration are to improve the health, vigor, and diversity of the ecosystem--and these goals can and...

  14. Groundwater monitoring systems and groundwater quality in the administrative district of Detmold (North Rhine-Westphalia)

    International Nuclear Information System (INIS)

    Grabau, J.

    1994-01-01

    Two groundwater monitoring systems for areas of different dimensions in the administrative district of Detmold are introduced. Firstly, the monitoring of groundwater and untreated water by the Water Conservation and Waste Disposal Authority (Amt fuer Wasser- und Abfallwirtschaft) in Minden and secondly, the monitoring of groundwater and drinking water by the Water Resources Board (Wasserschutzamt) in Bielefeld. Different approaches and methods are required for the description of groundwater quality on a regional and a local basis, respectively, i.e. for the monitoring of a whole region and the monitoring of parts of such a region. The properties of groundwater in areas of different dimensions are analysed and described by means of an extensive database and with the help of (geo)statistical methods of analysis. Existing hydrochemical data have only limited value as evidence of groundwater properties in the dimensional units ''region'' and ''small investigation area''. They often do not meet the requirements of correct mathematical statistical methods. (orig.)

  15. Management systems for environmental restoration projects

    International Nuclear Information System (INIS)

    Harbert, R.R.

    1990-01-01

    This paper reports that the success fo large environmental restoration projects depends on sound management systems to guide the team of organizations and individuals responsible for the project. Public concern about and scrutiny of these environmental projects increase the stakes for those involved in the management of projects. The Department of Energy (DOE) Formerly Utilized Sites Remedial Action Program (FUSRAP) uses a system approach to performing and improving the work necessary to meet FUSRAP objectives. This approach to preforming and improving the work necessary to meet FUSRAP objectives. This approach is based upon management criteria embodied in DOE cost and schedule control system and the quality assurance requirements. The project team used complementary criteria to develop a system of related parts and processes working together to accomplish the goals of the project

  16. Anterior provisional restorations used to determine form, function, and esthetics for complex restorative situations, using all-ceramic restorative systems.

    Science.gov (United States)

    Reshad, Mamaly; Cascione, Domenico; Kim, Tae

    2010-02-01

    A technique is proposed for the restoration of a large and visible maxillary anterior defect. The importance of proper diagnosis, treatment planning, and communication is emphasized. Irreversible treatment should only be rendered once patient approval has been obtained through objective evaluation with provisional restorations. The techniques presented in this article use a combination of ceramic systems currently available to satisfy functional demands while achieving acceptable esthetics. A controlled series of steps, where the provisional restorative components are being replaced by the definitive ones is planned. The only difference between the provisional and definitive restorative components is the material used. The definitive restorations consisted of an implant-supported zirconium oxide framework. Individual pressed porcelain restorations were luted to the framework and a natural tooth. CLINICAL SIGNIFICANCE Provisional restorations allow an objective form of communication. Vertical and horizontal transitional lines can be effectively masked with appropriate treatment planning and a skilled ceramist. Many traditional dental laboratory steps may be eliminated or simplified without compromising the definitive restorations.

  17. Infrastructure system restoration planning using evolutionary algorithms

    Science.gov (United States)

    Corns, Steven; Long, Suzanna K.; Shoberg, Thomas G.

    2016-01-01

    This paper presents an evolutionary algorithm to address restoration issues for supply chain interdependent critical infrastructure. Rapid restoration of infrastructure after a large-scale disaster is necessary to sustaining a nation's economy and security, but such long-term restoration has not been investigated as thoroughly as initial rescue and recovery efforts. A model of the Greater Saint Louis Missouri area was created and a disaster scenario simulated. An evolutionary algorithm is used to determine the order in which the bridges should be repaired based on indirect costs. Solutions were evaluated based on the reduction of indirect costs and the restoration of transportation capacity. When compared to a greedy algorithm, the evolutionary algorithm solution reduced indirect costs by approximately 12.4% by restoring automotive travel routes for workers and re-establishing the flow of commodities across the three rivers in the Saint Louis area.

  18. Hydrogeochemical characterization of Bacolod City groundwater system

    International Nuclear Information System (INIS)

    Sucgang, Raymond J.; Almoneda, Rosalina; Fernandez, Lourdes; Castaneda, Soledad S.; Gemora, Jenelyn Y.; Desengano, Daisy; Lim, Fatima

    2007-01-01

    Groundwater is constantly being recycled and replenished by rainfall. However, because of the uneven distribution of rain and the heavy use of water in certain areas, some regions are experiencing undue water shortage. Changes in land use, population growth, and economic development in the Bacolod City region, can result in an increase in water demand and the generation of additional pollution sources. To delineate the ground water recharge area for Bacolod City and at the same time, assess the vulnerability of the aquifer to pollution, water samples were collected in an attempt to relate chemical variations in ground water to the underlying differences in geology, availability and mechanism of recharge, and to define the natural versus anthropogenic influences in the groundwater system. Measurements of field data such as pH, conductivity, temperature and alkalinity were made. Several geochemical processes are recognized in the chemistry of the Bacolod aquifer system. The most important processes are: water-bedrock interaction, dissolution of connate halites , and seawater intrusion. Simple mass balance modeling shows that the feasible source of active recharge aside from direct precipitation, is infiltration from the Loygoy river. Rivers and tributaries transport water originated as precipitation falling at higher elevations. The ground water in Bacolod City is predominantly of the Ca-Mg-HCO 3 type. Recharge becomes sodium dominated along its path, indicating a slow but active mechanism. The ground water near the coasts is brackish due to sea water infiltration. The possible presence of connate halites lying in the deep aquifers is also indicated. The information generated, when used in conjunction with isotopic techniques, will be important in the choice of sites for pumping stations and in the knowledge of the extent of potential pollution of ground water from streams/reservoirs. (author)

  19. Understanding similarity of groundwater systems with empirical copulas

    Science.gov (United States)

    Haaf, Ezra; Kumar, Rohini; Samaniego, Luis; Barthel, Roland

    2016-04-01

    Within the classification framework for groundwater systems that aims for identifying similarity of hydrogeological systems and transferring information from a well-observed to an ungauged system (Haaf and Barthel, 2015; Haaf and Barthel, 2016), we propose a copula-based method for describing groundwater-systems similarity. Copulas are an emerging method in hydrological sciences that make it possible to model the dependence structure of two groundwater level time series, independently of the effects of their marginal distributions. This study is based on Samaniego et al. (2010), which described an approach calculating dissimilarity measures from bivariate empirical copula densities of streamflow time series. Subsequently, streamflow is predicted in ungauged basins by transferring properties from similar catchments. The proposed approach is innovative because copula-based similarity has not yet been applied to groundwater systems. Here we estimate the pairwise dependence structure of 600 wells in Southern Germany using 10 years of weekly groundwater level observations. Based on these empirical copulas, dissimilarity measures are estimated, such as the copula's lower- and upper corner cumulated probability, copula-based Spearman's rank correlation - as proposed by Samaniego et al. (2010). For the characterization of groundwater systems, copula-based metrics are compared with dissimilarities obtained from precipitation signals corresponding to the presumed area of influence of each groundwater well. This promising approach provides a new tool for advancing similarity-based classification of groundwater system dynamics. Haaf, E., Barthel, R., 2015. Methods for assessing hydrogeological similarity and for classification of groundwater systems on the regional scale, EGU General Assembly 2015, Vienna, Austria. Haaf, E., Barthel, R., 2016. An approach for classification of hydrogeological systems at the regional scale based on groundwater hydrographs EGU General Assembly

  20. Radionuclides in groundwater flow system understanding

    Science.gov (United States)

    Erőss, Anita; Csondor, Katalin; Horváth, Ákos; Mádl-Szőnyi, Judit; Surbeck, Heinz

    2017-04-01

    Using radionuclides is a novel approach to characterize fluids of groundwater flow systems and understand their mixing. Particularly, in regional discharge areas, where different order flow systems convey waters with different temperature, composition and redox-state to the discharge zone. Radium and uranium are redox-sensitive parameters, which causes fractionation along groundwater flow paths. Discharging waters of regional flow systems are characterized by elevated total dissolved solid content (TDS), temperature and by reducing conditions, and therefore with negligible uranium content, whereas local flow systems have lower TDS and temperature and represent oxidizing environments, and therefore their radium content is low. Due to the short transit time, radon may appear in local systems' discharge, where its source is the soil zone. However, our studies revealed the importance of FeOOH precipitates as local radon sources throughout the adsorption of radium transported by the thermal waters of regional flow systems. These precipitates can form either by direct oxidizing of thermal waters at discharge, or by mixing of waters with different redox state. Therefore elevated radon content often occurs in regional discharge areas as well. This study compares the results of geochemical studies in three thermal karst areas in Hungary, focusing on radionuclides as natural tracers. In the Buda Thermal Karst, the waters of the distinct discharge areas are characterized by different temperature and chemical composition. In the central discharge area both lukewarm (20-35°C, 770-980 mg/l TDS) and thermal waters (40-65°C, 800-1350 mg/l TDS), in the South only thermal water discharge (33-43°C, 1450-1700 mg/l TDS) occur. Radionuclides helped to identify mixing of fluids and to infer the temperature and chemical composition of the end members for the central discharge area. For the southern discharge zone mixing components could not be identified, which suggests different cave

  1. Groundwater detection monitoring system design under conditions of uncertainty

    NARCIS (Netherlands)

    Yenigül, N.B.

    2006-01-01

    Landfills represent a wide-spread and significant threat to groundwater quality. In this thesis a methodology was developed for the design of optimal groundwater moni-toring system design at landfill sites under conditions of uncertainty. First a decision analysis approach was presented for optimal

  2. 40 CFR 258.51 - Ground-water monitoring systems.

    Science.gov (United States)

    2010-07-01

    ... water that has not been affected by leakage from a unit. A determination of background quality may... that ensures detection of ground-water contamination in the uppermost aquifer. When physical obstacles... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground-water monitoring systems. 258...

  3. Martin Marietta Energy Systems, Inc., Groundwater Program Management Plan

    International Nuclear Information System (INIS)

    Early, T.O.

    1994-05-01

    The purpose of the Martin Marietta Energy Systems, Inc., (Energy Systems) Groundwater Program Management Plan is to define the function, organizational structure (including associated matrix organizations), interfaces, roles and responsibilities, authority, and relationship to the Department of Energy for the Energy Systems Groundwater Program Office (GWPO). GWPO is charged with the responsibility of coordinating all components of the groundwater program for Energy Systems. This mandate includes activities at the three Oak Ridge facilities [Oak Ridge National Laboratory, the Oak Ridge Y-12 Plant, and the Oak Ridge K-25 Site], as well as the Paducah and Portsmouth Gaseous Diffusion Plants

  4. Martin Marietta Energy Systems, Inc., Groundwater Program Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Early, T.O.

    1994-05-01

    The purpose of the Martin Marietta Energy Systems, Inc., (Energy Systems) Groundwater Program Management Plan is to define the function, organizational structure (including associated matrix organizations), interfaces, roles and responsibilities, authority, and relationship to the Department of Energy for the Energy Systems Groundwater Program Office (GWPO). GWPO is charged with the responsibility of coordinating all components of the groundwater program for Energy Systems. This mandate includes activities at the three Oak Ridge facilities [Oak Ridge National Laboratory, the Oak Ridge Y-12 Plant, and the Oak Ridge K-25 Site], as well as the Paducah and Portsmouth Gaseous Diffusion Plants.

  5. Microbial degradation of chloroethenes in groundwater systems

    Science.gov (United States)

    Bradley, Paul M.

    The chloroethenes, tetrachloroethene (PCE) and trichloroethene (TCE) are among the most common contaminants detected in groundwater systems. As recently as 1980, the consensus was that chloroethene compounds were not significantly biodegradable in groundwater. Consequently, efforts to remediate chloroethene-contaminated groundwater were limited to largely unsuccessful pump-and-treat attempts. Subsequent investigation revealed that under reducing conditions, aquifer microorganisms can reductively dechlorinate PCE and TCE to the less chlorinated daughter products dichloroethene (DCE) and vinyl chloride (VC). Although recent laboratory studies conducted with halorespiring microorganisms suggest that complete reduction to ethene is possible, in the majority of groundwater systems reductive dechlorination apparently stops at DCE or VC. However, recent investigations conducted with aquifer and stream-bed sediments have demonstrated that microbial oxidation of these reduced daughter products can be significant under anaerobic redox conditions. The combination of reductive dechlorination of PCE and TCE under anaerobic conditions followed by anaerobic microbial oxidation of DCE and VC provides a possible microbial pathway for complete degradation of chloroethene contaminants in groundwater systems. Résumé Les chloroéthanes, tétrachloroéthane (PCE) et trichloroéthane (TCE) sont parmi les polluants les plus communs trouvés dans les aquifères. Depuis les années 1980, on considère que les chloroéthanes ne sont pas significativement biodégradables dans les aquifères. Par conséquent, les efforts pour dépolluer les nappes contaminées par des chloroéthanes se sont limités à des tentatives de pompage-traitement globalement sans succès. Des travaux ultérieurs ont montré que dans des conditions réductrices, des micro-organismes présents dans les aquifères peuvent, par réduction, dégrader les PCE et TCE en composés moins chlorés, comme le dichlor

  6. Design of groundwater pollution expert system: forward chaining and interfacing

    International Nuclear Information System (INIS)

    Mongkon Ta-oun; Mohamed Daud; Mohd Zohadie Bardaie; Shamshuddin Jusop

    2000-01-01

    The groundwater pollution expert system (GWPES was developed by C Language Integrate Production System (CLEPS). The control techniques of this system consider some conclusion and then attempts to prove it by searching for supportive information from the database. The inference process goes in forward chaining of this system such as predicting groundwater pollution vulnerability, predicting the effect of nitrogen fertiliser, agricultural impact and project development on groundwater pollution potential. In GWPES, forward chaining system begins with a matching of inputs with the existing database of groundwater environment and activities impact of the project development. While, interaction between an expert system and user is conducted in simple English language. The interaction is highly interactive. A basis design with simple Graphic User Interface (GUI) to input data and by asking simple questions. (author)

  7. INDICTORS OF RESTORATION OF PROGRAM FACILITY OF MECHATRONICS SYSTEM

    Directory of Open Access Journals (Sweden)

    V. Frolov

    2009-01-01

    Full Text Available The determination of reliability indictors of program facilities of mechatronic systems are offered. The defaillance modes of program facilities are represent. A short review of model reliability of program facility is presented. The indictors of restoration, their mathematical determinations and application for the characteristics of program facility restoration are offered.

  8. Robustness Area Technique Developing Guidelines for Power System Restoration

    Directory of Open Access Journals (Sweden)

    Paulo Murinelli Pesoti

    2017-01-01

    Full Text Available This paper proposes a novel energy based technique called the Robustness Area (RA technique that measures power system robustness levels, as a helper for planning Power System Restorations (PSRs. The motivation is on account of the latest blackouts in Brazil, where the local Independent System Operator (ISO encountered difficulties related to circuit disconnections during the restoration. The technique identifies vulnerable and robust buses, pointing out system areas that should be firstly reinforced during PSR, in order to enhance system stability. A Brazilian power system restoration area is used to compare the guidelines adopted by the ISO with a more suitable new plan indicated by the RA tool. Active power and reactive power load margin and standing phase angle show the method efficiency as a result of a well balanced system configuration, enhancing the restoration performance. Time domain simulations for loop closures and severe events also show the positive impact that the proposed tool brings to PSRs.

  9. A systems approach to restoring degraded drylands

    Science.gov (United States)

    Jeremy J. James; Roger L. Sheley; Todd Erickson; Kimberly S. Rollins; Michael H. Taylor; Kingsley W. Dixon

    2013-01-01

    Drylands support over 2 billion people and are major providers of critical ecosystem goods and services across the globe. Drylands, however, are one of the most susceptible biomes to degradation. International programmes widely recognize dryland restoration as key to combating global dryland degradation and ensuring future global sustainability. While the need to...

  10. Modeling irrigation behavior in groundwater systems

    Science.gov (United States)

    Foster, Timothy; Brozović, Nicholas; Butler, Adrian P.

    2014-08-01

    Integrated hydro-economic models have been widely applied to water management problems in regions of intensive groundwater-fed irrigation. However, policy interpretations may be limited as most existing models do not explicitly consider two important aspects of observed irrigation decision making, namely the limits on instantaneous irrigation rates imposed by well yield and the intraseasonal structure of irrigation planning. We develop a new modeling approach for determining irrigation demand that is based on observed farmer behavior and captures the impacts on production and water use of both well yield and climate. Through a case study of irrigated corn production in the Texas High Plains region of the United States we predict optimal irrigation strategies under variable levels of groundwater supply, and assess the limits of existing models for predicting land and groundwater use decisions by farmers. Our results show that irrigation behavior exhibits complex nonlinear responses to changes in groundwater availability. Declining well yields induce large reductions in the optimal size of irrigated area and irrigation use as constraints on instantaneous application rates limit the ability to maintain sufficient soil moisture to avoid negative impacts on crop yield. We demonstrate that this important behavioral response to limited groundwater availability is not captured by existing modeling approaches, which therefore may be unreliable predictors of irrigation demand, agricultural profitability, and resilience to climate change and aquifer depletion.

  11. Intelligent decision support algorithm for distribution system restoration.

    Science.gov (United States)

    Singh, Reetu; Mehfuz, Shabana; Kumar, Parmod

    2016-01-01

    Distribution system is the means of revenue for electric utility. It needs to be restored at the earliest if any feeder or complete system is tripped out due to fault or any other cause. Further, uncertainty of the loads, result in variations in the distribution network's parameters. Thus, an intelligent algorithm incorporating hybrid fuzzy-grey relation, which can take into account the uncertainties and compare the sequences is discussed to analyse and restore the distribution system. The simulation studies are carried out to show the utility of the method by ranking the restoration plans for a typical distribution system. This algorithm also meets the smart grid requirements in terms of an automated restoration plan for the partial/full blackout of network.

  12. A new separation and treatment method for soil and groundwater restoration

    Energy Technology Data Exchange (ETDEWEB)

    Hitchens, G.D. [Lynntech, Inc., College Station, TX (United States)

    1997-10-01

    Soil and groundwater contamination by organic compounds is a widespread environmental pollution problem. In many cases, contaminated soil is excavated and transported to a landfill or is incinerated to remove contaminants. These remediation practices are expensive, environmentally disruptive, require extensive permitting, and only move contamination from one location to another. Onsite and in situ treatment techniques offer a safer, more cost-effective, and permanent solution. Many soil and groundwater contaminants are highly volatile, enabling the use of methods such as in situ vacuum extraction and air injection for their removal. However, these methods are often difficult to use because of slow volatilization rates and the lack of effective methods to treat the extracted hazardous material. This Phase I Small Business Innovation Research program focuses on developing an in situ soil and groundwater remediation technique that is effective against volatile as well as nonvolatile compounds and that will shorten treatment times. The technique forms the basis of a new catalytic process to degrade extracted contaminants onsite. Key hardware elements on which the new technique is based have been proven in preliminary research. The method has a high potential for public and regulatory acceptance because of its low environment impact.

  13. A new separation and treatment method for soil and groundwater restoration

    International Nuclear Information System (INIS)

    Hitchens, G.D.

    1997-01-01

    Soil and groundwater contamination by organic compounds is a widespread environmental pollution problem. In many cases, contaminated soil is excavated and transported to a landfill or is incinerated to remove contaminants. These remediation practices are expensive, environmentally disruptive, require extensive permitting, and only move contamination from one location to another. Onsite and in situ treatment techniques offer a safer, more cost-effective, and permanent solution. Many soil and groundwater contaminants are highly volatile, enabling the use of methods such as in situ vacuum extraction and air injection for their removal. However, these methods are often difficult to use because of slow volatilization rates and the lack of effective methods to treat the extracted hazardous material. This Phase I Small Business Innovation Research program focuses on developing an in situ soil and groundwater remediation technique that is effective against volatile as well as nonvolatile compounds and that will shorten treatment times. The technique forms the basis of a new catalytic process to degrade extracted contaminants onsite. Key hardware elements on which the new technique is based have been proven in preliminary research. The method has a high potential for public and regulatory acceptance because of its low environment impact

  14. Restoring Detroit's Street Lighting System

    Energy Technology Data Exchange (ETDEWEB)

    Kinzey, Bruce [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-30

    The City of Detroit is in the midst of a comprehensive restoration of its street lighting system that includes transitioning the existing HPS sources to LED. This report provides an objective review of the circumstances surrounding the system restoration, the processes undertaken and decisions made, and the results so far — and contains useful information about issues that arise during large-scale LED street lighting projects.

  15. The importance of groundwater-derived carbon dioxide in the restoration of small Sphagnum bogs

    NARCIS (Netherlands)

    Patberg, Wouter; Baaijens, Gert Jan; Smolders, Alfons J. P.; Grootjans, Ab P.; Elzenga, J. Theo M.

    Essential for successful bog restoration is the reestablishment of Sphagnum mosses. High carbon dioxide availability has been shown to be of great importance for the growth of Sphagnum mosses. In well-developed Sphagnum bogs large amounts of carbon dioxide are produced by (an)aerobic decomposition

  16. Stochastic modeling of wetland-groundwater systems

    Science.gov (United States)

    Bertassello, Leonardo Enrico; Rao, P. Suresh C.; Park, Jeryang; Jawitz, James W.; Botter, Gianluca

    2018-02-01

    Modeling and data analyses were used in this study to examine the temporal hydrological variability in geographically isolated wetlands (GIWs), as influenced by hydrologic connectivity to shallow groundwater, wetland bathymetry, and subject to stochastic hydro-climatic forcing. We examined the general case of GIWs coupled to shallow groundwater through exfiltration or infiltration across wetland bottom. We also examined limiting case with the wetland stage as the local expression of the shallow groundwater. We derive analytical expressions for the steady-state probability density functions (pdfs) for wetland water storage and stage using few, scaled, physically-based parameters. In addition, we analyze the hydrologic crossing time properties of wetland stage, and the dependence of the mean hydroperiod on climatic and wetland morphologic attributes. Our analyses show that it is crucial to account for shallow groundwater connectivity to fully understand the hydrologic dynamics in wetlands. The application of the model to two different case studies in Florida, jointly with a detailed sensitivity analysis, allowed us to identify the main drivers of hydrologic dynamics in GIWs under different climate and morphologic conditions.

  17. Sequential Service Restoration for Unbalanced Distribution Systems and Microgrids

    International Nuclear Information System (INIS)

    Chen, Bo; Chen, Chen; Wang, Jianhui; Butler-Purry, Karen L.

    2017-01-01

    The resilience and reliability of modern power systems are threatened by increasingly severe weather events and cyber-physical security events. An effective restoration methodology is desired to optimally integrate emerging smart grid technologies and pave the way for developing self-healing smart grids. In this paper, a sequential service restoration (SSR) framework is proposed to generate restoration solutions for distribution systems and microgrids in the event of large-scale power outages. The restoration solution contains a sequence of control actions that properly coordinate switches, distributed generators, and switchable loads to form multiple isolated microgrids. The SSR can be applied for three-phase unbalanced distribution systems and microgrids and can adapt to various operation conditions. Mathematical models are introduced for three-phase unbalanced power flow, voltage regulators, transformers, and loads. Furthermore, the SSR problem is formulated as a mixed-integer linear programming model, and its effectiveness is evaluated via the modified IEEE 123 node test feeder.

  18. 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.

  19. Groundwater Quality Assessment Based on Geographical Information System and Groundwater Quality Index

    Directory of Open Access Journals (Sweden)

    Zahra Derakhshan

    2015-06-01

    Full Text Available Iran is located in an arid and semi-arid part of the world. Accordingly, the management of the water resources in the country is a priority. In this regard, determining the quality and pollution of surface water and groundwater is very important, especially in areas where groundwater resources are used for drinking. Groundwater quality index (GQI checks the components of the available water with various quality levels. To assess the quality of drinking groundwater of Yazd-Ardakan plain according to GQI in geographical information system (GIS environment, the electrical conductivity, sodium, calcium, magnesium, chlorine, pH, sodium adsorption ratio, bicarbonate, sulfate, potassium, water hardness, and all substances dissolved in the waters of 80 wells were determined. The samples were obtained from Yazd Regional Water Organization from 2005 to 2014. Using this data, the map components were plotted by Kriging geostatistical method. Then, the map of GQI was prepared after normalizing each map component, switching to a rating map, and extracting the weight of each component from the rating map. Based on the GQI index map, the index point which was 87 in 2005 has increased to 81 in 2014. These maps show a decline in groundwater quality from west to the east region. This decline in groundwater quality is due to the existence of Neogene Organizations in the east and geomorphologic unit of the bare epandage pediment in the west. The map removal and single-parameter sensitivity analysis showed that GQI index in Yazd-Ardakan plain is more sensitive to the components of electrical conductivity (EC, total dissolved solids (TDS, and total hardness (TH. Therefore, these components should be monitored more carefully and repeatedly.

  20. Groundwater systems of the Indian Sub-Continent

    Directory of Open Access Journals (Sweden)

    Abhijit Mukherjee

    2015-09-01

    Full Text Available The Indian Sub-Continent is one of the most densely populated regions of the world, hosting ∼23% of the global population within only ∼3% of the world's land area. It encompasses some of the world's largest fluvial systems in the world (River Brahmaputra, Ganges and Indus Basins, which hosts some of the highest yielding aquifers in the world. The distribution of usable groundwater in the region varies considerably and the continued availability of safe water from many of these aquifers (e.g. Bengal Basin is constrained by the presence of natural contaminants. Further, the trans-boundary nature of the aquifers in the Indian Sub-Continent makes groundwater resource a potentially politically sensitive issue, particularly since this region is the largest user of groundwater resources in the world. Indeed, there is considerable concern regarding dwindling well yield and declining groundwater levels, even for the highly productive aquifers. Though irrigation already accounts for >85% of the total ground water extraction of the region, there is a mounting pressure on aquifers for food security of the region. Highly variable precipitation, hydrogeological conditions and predicted, impending climate change effects provide substantial challenges to groundwater management. The observed presence of natural groundwater contaminants together with the growing demand for irrigated food production and predicted climate change further complicate the development of strategies for using groundwater resources sustainably. We provide an introduction and overview of 11 articles, collated in this special issue, which describe the current condition of vulnerable groundwater resources across the Indian Sub-Continent.

  1. Use of the Empress all-ceramic restoration system.

    Science.gov (United States)

    Goulet, M K

    1997-01-01

    New dental materials and techniques have been introduced in the past few years to fabricate aesthetic ceramic restorations with improved strength, biocompatibility, resistance to wear, and better fit. Aesthetic concerns and increasing demand for tooth-colored posterior restorations have led to a number of all-ceramic restorations such as IPS Empress (Ivoclar-Williams, Amherst, NY). The Empress system offers superior aesthetics and physical properties. New generation ceramics along with the current adhesive techniques have resulted in the ability to provide higher strength, therefore indicating crowns for posterior restorations as well. These materials are being used more frequently and in more extensive oral prosthetic rehabilitations such as the case that will be presented. We discuss the different properties and advantages of IPS Empress.

  2. Rule base system in developing groundwater pollution expert system: predicting model

    International Nuclear Information System (INIS)

    Mongkon Ta-oun; Mohamed Daud; Mohd Zohadie Bardaie; Shamshuddin Jusop

    2000-01-01

    New techniques are now available for use in the protection of the environment. One of these techniques is the use of expert system for prediction groundwater pollution potential. Groundwater Pollution Expert system (GWPES) rules are a collection of principles and procedures used to know the comprehension of groundwater pollution prediction. The rules of groundwater pollution expert system in the form of questions, choice, radio-box, slide rule, button or frame are translated in to IF-THEN rule. The rules including of variables, types, domains and descriptions were used by the function of wxCLIPS (C Language Integrate Production System) expert system shell. (author)

  3. LANL environmental restoration site ranking system: System description. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Merkhofer, L.; Kann, A.; Voth, M. [Applied Decision Analysis, Inc., Menlo Park, CA (United States)

    1992-10-13

    The basic structure of the LANL Environmental Restoration (ER) Site Ranking System and its use are described in this document. A related document, Instructions for Generating Inputs for the LANL ER Site Ranking System, contains detailed descriptions of the methods by which necessary inputs for the system will be generated. LANL has long recognized the need to provide a consistent basis for comparing the risks and other adverse consequences associated with the various waste problems at the Lab. The LANL ER Site Ranking System is being developed to help address this need. The specific purpose of the system is to help improve, defend, and explain prioritization decisions at the Potential Release Site (PRS) and Operable Unit (OU) level. The precise relationship of the Site Ranking System to the planning and overall budget processes is yet to be determined, as the system is still evolving. Generally speaking, the Site Ranking System will be used as a decision aid. That is, the system will be used to aid in the planning and budgetary decision-making process. It will never be used alone to make decisions. Like all models, the system can provide only a partial and approximate accounting of the factors important to budget and planning decisions. Decision makers at LANL will have to consider factors outside of the formal system when making final choices. Some of these other factors are regulatory requirements, DOE policy, and public concern. The main value of the site ranking system, therefore, is not the precise numbers it generates, but rather the general insights it provides.

  4. LANL environmental restoration site ranking system: System description. Final report

    International Nuclear Information System (INIS)

    Merkhofer, L.; Kann, A.; Voth, M.

    1992-01-01

    The basic structure of the LANL Environmental Restoration (ER) Site Ranking System and its use are described in this document. A related document, Instructions for Generating Inputs for the LANL ER Site Ranking System, contains detailed descriptions of the methods by which necessary inputs for the system will be generated. LANL has long recognized the need to provide a consistent basis for comparing the risks and other adverse consequences associated with the various waste problems at the Lab. The LANL ER Site Ranking System is being developed to help address this need. The specific purpose of the system is to help improve, defend, and explain prioritization decisions at the Potential Release Site (PRS) and Operable Unit (OU) level. The precise relationship of the Site Ranking System to the planning and overall budget processes is yet to be determined, as the system is still evolving. Generally speaking, the Site Ranking System will be used as a decision aid. That is, the system will be used to aid in the planning and budgetary decision-making process. It will never be used alone to make decisions. Like all models, the system can provide only a partial and approximate accounting of the factors important to budget and planning decisions. Decision makers at LANL will have to consider factors outside of the formal system when making final choices. Some of these other factors are regulatory requirements, DOE policy, and public concern. The main value of the site ranking system, therefore, is not the precise numbers it generates, but rather the general insights it provides

  5. Work plan for the Oak Ridge National Laboratory groundwater program: Continuous groundwater collection

    International Nuclear Information System (INIS)

    1995-08-01

    The continuous collection of groundwater data is a basic and necessary part of Lockeheed Martin Energy Systems' ORNL Environmental Restoration Area-Wide Groundwater Program. Continuous groundwater data consist primarily of continually recorded groundwater levels, and in some instances, specific conductivity, pH, and/or temperature measurements. These data will be collected throughout the ORNL site. This Work Plan (WP) addresses technical objectives, equipment requirements, procedures, documentation requirements, and technical instructions for the acquisition of the continuous groundwater data. Intent of this WP is to provide an approved document that meets all the necessary requirements while retaining the flexibility necessary to effectively address ORNL's groundwater problems

  6. A Method to Evaluate Groundwater flow system under the Seabed

    Science.gov (United States)

    Kohara, N.; Marui, A.

    2011-12-01

    / fresh water interface (position of the submarine groundwater discharge) may appear on the seafloor. Moreover, neither the salinity concentration nor the groundwater age depends on depth. It is thought that it is because that the groundwater forms the complex flow situation through the change in a long-term groundwater flow system. The technology to understand the coastal groundwater flow consists of remote sensing, geographical features analysis, surface of the earth investigation, geophysical exploration, drilling survey, and indoor examination and the measurement. Integration of each technology is needed to interpret groundwater flow system because the one is to catch the local groundwater flow in the time series and another one is to catch the long-term and regional groundwater flow in the general situation. The purpose of this study is to review the previous research of coastal groundwater flow, and to integrate an applicable evaluation approach to understand this mechanism. In this presentation, the review of the research and case study using numerical simulation are introduced.

  7. Restoring Detroit's Street Lighting System

    Energy Technology Data Exchange (ETDEWEB)

    Kinzey, Bruce R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-10-21

    The City of Detroit is undertaking a comprehensive restoration of its street lighting system that includes transitioning the existing high-pressure sodium (HPS) sources to light-emitting diode (LED). Detroit’s well-publicized financial troubles over the last several years have added many hurdles and constraints to this process. Strategies to overcome these issues have largely been successful, but have also brought some mixed results. This document provides an objective review of the circumstances surrounding the system restoration, the processes undertaken and decisions made, and the results so far.

  8. RESTORATIVE JUSTICE DALAM SISTEM PERADILAN PIDANA ANAK / Restorative Justice In Juvenile Justice System

    Directory of Open Access Journals (Sweden)

    Randy Pradityo

    2016-11-01

    Full Text Available Anak sebagai generasi penerus bangsa sudah selayaknya mendapatkan perhatian khusus. Hal tersebut bertujuan dalam rangka pembinaan anak untuk mewujudkan sumber daya manusia yang berkualitas. Maka dari itu, diperlukan pula sarana dan prasarana hukum yang mengantisipasi segala permasalahan yang timbul. Sarana hukum ini bertujuan untuk mengantisipasi stigma atau cap jahat yang ditimbulkan ketika anak berhadapan dengan hukum, sekaligus memulihkan dan memasyarakatkan kembali anak tersebut. Salah satu solusinya adalah dengan mengalihkan atau menempatkan pelaku tindak pidana anak keluar dari sistem peradilan pidana serta memberikan alternatif bagi penyelesaian dengan pendekatan keadilan demi kepentingan terbaik bagi anak, yang kemudian dikenal dengan pendekatan restorative justice. Restorative justice yang merupakan implementasi konsep dari diversi telah dirumuskan dalam sistem peradilan pidana anak, namun sistem yang baik haruslah diiringi dengan suatu sikap yang dijiwai kehendak untuk memandang dan berkeyakinan bahwa dunia ini selalu menjadi lebih baik. Selain itu, hendaknya prinsip the best interest of the children selalu diutamakan ketika menangani anak yang berhadapan dengan hukum.   Children as the nation's next generation is already deserve special attention. It aims in order to develop the child to realize the quality of human resources. Therefore, it is also necessary legal infrastructure to anticipate any problems that arise. The legal means to anticipate stigma or stamp evil inflicted when the child against the law, as well as restoring and re-socialize the child. One solution is to divert or placing the offender children out of the criminal justice system as well as providing an alternative to the settlement with justice approach in the best interests of the child, who was then known as restorative justice approach. Restorative justice which is the implementation of the concept of diversion has been formulated in the juvenile justice system

  9. Real-time image restoration for iris recognition systems.

    Science.gov (United States)

    Kang, Byung Jun; Park, Kang Ryoung

    2007-12-01

    In the field of biometrics, it has been reported that iris recognition techniques have shown high levels of accuracy because unique patterns of the human iris, which has very many degrees of freedom, are used. However, because conventional iris cameras have small depth-of-field (DOF) areas, input iris images can easily be blurred, which can lead to lower recognition performance, since iris patterns are transformed by the blurring caused by optical defocusing. To overcome these problems, an autofocusing camera can be used. However, this inevitably increases the cost, size, and complexity of the system. Therefore, we propose a new real-time iris image-restoration method, which can increase the camera's DOF without requiring any additional hardware. This paper presents five novelties as compared to previous works: 1) by excluding eyelash and eyelid regions, it is possible to obtain more accurate focus scores from input iris images; 2) the parameter of the point spread function (PSF) can be estimated in terms of camera optics and measured focus scores; therefore, parameter estimation is more accurate than it has been in previous research; 3) because the PSF parameter can be obtained by using a predetermined equation, iris image restoration can be done in real-time; 4) by using a constrained least square (CLS) restoration filter that considers noise, performance can be greatly enhanced; and 5) restoration accuracy can also be enhanced by estimating the weight value of the noise-regularization term of the CLS filter according to the amount of image blurring. Experimental results showed that iris recognition errors when using the proposed restoration method were greatly reduced as compared to those results achieved without restoration or those achieved using previous iris-restoration methods.

  10. Microbes Characteristics in Groundwater Flow System in Mountainous Area

    Science.gov (United States)

    Yamamoto, Chisato; Tsujimura, Maki; Kato, Kenji; Sakakibara, Koichi; Ogawa, Mahiro; Sugiyama, Ayumi; Nagaosa, Kazuyo

    2017-04-01

    We focus on a possibility of microbes as a tracer for groundwater flow investigation. Some previous papers showed that the total number of prokaryotes in groundwater has correlation with depth and geology (Parkes et al., 1994; Griebler et al., 2009; Kato et al., 2012). However, there are few studies investigating both microbe characteristics and groundwater flow system. Therefore, we investigated a relationship between the total number of prokaryotes and age of spring water and groundwater. Intensive field survey was conducted at four mountainous areas, namely Mt. Fuji (volcano), a headwater at Mt. Setohachi, a headwater at River Oi and a headwater at River Nagano underlain by volcanic lava at Mt. Fuji, granite at Mt. Setohachi and sedimentary rock at River Oi and River Nagano. We collected totally 40 spring water/ groundwater samples in these mountainous areas in October 2015, August, October and November 2016 and analyzed concentration of inorganic ions, the stable isotopes of oxygen - 18, deuterium, CFCs and SF6. Also, we counted prokaryotic cells under the epifluorescence microscopy after fixation and filteration. The total number of prokaryotes in the spring water/ groundwater ranged from 1.0×102 to 7.0×103cells mL-1 at the Mt. Fuji, 1.3×104 to 2.7×105cells mL-1 at Mt. Setohachi, 3.1×104cells mL-1 at River Oi and 1.8×105 to 3.2×106cells mL-1 at River Nagano. The SF6 age of the spring water/ groundwater ranged from 8 to 64 years at Mt. Fuji, 2 to 32.5 years at Mt. Setohachi, 2.5 years at River Oi and 15 to 16 years at River Nagano. The total number of prokaryotes showed a clear negative correlation with residence time of spring water/ groundwater in all regions. Especially the prokaryotes number increased in the order of 102 cells mL-1 with decreasing of residence time in approximately 10 years in the groundwater and spring water with the age less than 15 years.

  11. Groundwater vulnerability mapping in Guadalajara aquifers system (Western Mexico)

    Science.gov (United States)

    Rizo-Decelis, L. David; Marín, Ana I.; Andreo, Bartolomé

    2016-04-01

    Groundwater vulnerability mapping is a practical tool to implement strategies for land-use planning and sustainable socioeconomic development coherent with groundwater protection. The objective of vulnerability mapping is to identify the most vulnerable zones of catchment areas and to provide criteria for protecting the groundwater used for drinking water supply. The delineation of protection zones in fractured aquifers is a challenging task due to the heterogeneity and anisotropy of hydraulic conductivities, which makes difficult prediction of groundwater flow organization and flow velocities. Different methods of intrinsic groundwater vulnerability mapping were applied in the Atemajac-Toluquilla groundwater body, an aquifers system that covers around 1300 km2. The aquifer supplies the 30% of urban water resources of the metropolitan area of Guadalajara (Mexico), where over 4.6 million people reside. Study area is located in a complex neotectonic active volcanic region in the Santiago River Basin (Western Mexico), which influences the aquifer system underneath the city. Previous works have defined the flow dynamics and identified the origin of recharge. In addition, the mixture of fresh groundwater with hydrothermal and polluted waters have been estimated. Two main aquifers compose the multilayer system. The upper aquifer is unconfined and consists of sediments and pyroclastic materials. Recharge of this aquifer comes from rainwater and ascending vertical fluids from the lower aquifer. The lower aquifer consists of fractured basalts of Pliocene age. Formerly, the main water source has been the upper unit, which is a porous and unconsolidated unit, which acts as a semi-isotropic aquifer. Intense groundwater usage has resulted in lowering the water table in the upper aquifer. Therefore, the current groundwater extraction is carried out from the deeper aquifer and underlying bedrock units, where fracture flow predominates. Pollution indicators have been reported in

  12. Modelling of the chemical state in groundwater infiltration systems

    International Nuclear Information System (INIS)

    Zysset, A.

    1993-01-01

    Groundwater is replenished by water stemming either from precipitations, lakes or rivers. The area where such an infiltration occurs is characterized by a change in the environmental conditions, such as a decrease of the flow velocity and an increase in the solid surface marking the boundary of the flow field. With these changes new chemical processes may become relevant to the transport behavior of contaminants. Since the rates of chemical processes usually are a function of the concentrations of several species, an understanding of infiltration sites may require a multicomponent approach. The present study aims at formulating a mathematical model together with its numerical solution for groundwater infiltration sites. Such a model should improve the understanding of groundwater quality changes related to infiltrating contaminants. The groundwater quality is of vital interest to men because at many places most of the drinking water originates from groundwater. In the first part of the present study two partial models are formulated: one accounting for the transport in a one-dimensional, homogeneous and saturated porous medium, the other accounting for chemical reactions. This second model is initially stated for general kinetic systems. Then, it is specified for two systems, namely for a system governed only by reactions which are fast compared to the transport processes and for a system with biologically mediated redox reactions of dissolved substrates. In the second part of the study a numerical solution to the model is developed. For this purpose, the two partial models are coupled. The coupling is either iterative as in the case of a system with fast reactions or sequential as in all other cases. The numerical solutions of simple test cases are compared to analytical solutions. In the third part the model is evaluated using observations of infiltration sites reported in the literature. (author) figs., tabs., 155 refs

  13. A New Power System Restoration Technique based on WAMS Partitioning

    Directory of Open Access Journals (Sweden)

    N. V. Phanendra Babu

    2017-08-01

    Full Text Available An important feature of a Wide-Area Measurement System (WAMS is the ability to recover data during a communication failure. This paper presents a novel scheme of partitioning a PMU installed power network into a number of WAMS regions in order to make the power system restoration process simpler. This algorithm also proposes the optimal placement of Phasor Data Concentrators (PDCs in each region to record the data from PMUs. This paper considers the restoration constraints like transformer equivalent bus, generation-load balance and the observability of region for the partitioning of power system. The proposed scheme is demonstrated with an IEEE-30 bus system. It is then applied on IEEE-39, IEEE-118 bus systems and on a Northern Regional Grid of the Indian Power Grid.

  14. Integrating a Linear Signal Model with Groundwater and Rainfall time-series on the Characteristic Identification of Groundwater Systems

    Science.gov (United States)

    Chen, Yu-Wen; Wang, Yetmen; Chang, Liang-Cheng

    2017-04-01

    Groundwater resources play a vital role on regional supply. To avoid irreversible environmental impact such as land subsidence, the characteristic identification of groundwater system is crucial before sustainable management of groundwater resource. This study proposes a signal process approach to identify the character of groundwater systems based on long-time hydrologic observations include groundwater level and rainfall. The study process contains two steps. First, a linear signal model (LSM) is constructed and calibrated to simulate the variation of underground hydrology based on the time series of groundwater levels and rainfall. The mass balance equation of the proposed LSM contains three major terms contain net rate of horizontal exchange, rate of rainfall recharge and rate of pumpage and four parameters are required to calibrate. Because reliable records of pumpage is rare, the time-variant groundwater amplitudes of daily frequency (P ) calculated by STFT are assumed as linear indicators of puamage instead of pumpage records. Time series obtained from 39 observation wells and 50 rainfall stations in and around the study area, Pintung Plain, are paired for model construction. Second, the well-calibrated parameters of the linear signal model can be used to interpret the characteristic of groundwater system. For example, the rainfall recharge coefficient (γ) means the transform ratio between rainfall intention and groundwater level raise. The area around the observation well with higher γ means that the saturated zone here is easily affected by rainfall events and the material of unsaturated zone might be gravel or coarse sand with high infiltration ratio. Considering the spatial distribution of γ, the values of γ decrease from the upstream to the downstream of major rivers and also are correlated to the spatial distribution of grain size of surface soil. Via the time-series of groundwater levels and rainfall, the well-calibrated parameters of LSM have

  15. Climate proxy data as groundwater tracers in regional flow systems

    Science.gov (United States)

    Clark, J. F.; Morrissey, S. K.; Stute, M.

    2008-05-01

    The isotopic and chemical signatures of groundwater reflect local climate conditions. By systematically analyzing groundwater and determining their hydrologic setting, records of past climates can be constructed. Because of their chemistries and relatively uncomplicated source functions, dissolved noble gases have yielded reliable records of continental temperatures for the last 30,000 to 50,000 years. Variations in the stable isotope compositions of groundwater due to long term climate changes have also been documented over these time scales. Because glacial - interglacial climate changes are relatively well known, these climate proxies can be used as "stratigraphic" markers within flow systems and used to distinguish groundwaters that have recharged during the Holocene from those recharged during the last glacial period, important time scales for distinguishing regional and local flow systems in many aquifers. In southern Georgia, the climate proxy tracers were able to identify leakage from surface aquifers into the Upper Floridan aquifer in areas previously thought to be confined. In south Florida, the transition between Holocene and glacial signatures in the Upper Floridan aquifer occurs mid-way between the recharge area and Lake Okeechobee. Down gradient of the lake, the proxies are uniform, indicating recharge during the last glacial period. Furthermore, there is no evidence for leakage from the shallow aquifers into the Upper Floridan. In the Lower Floridan, the climate proxies indicate that the saline water entered the aquifer after sea level rose to its present level.

  16. Data base dictionary for the Oak Ridge Reservation Hydrology and Geology Study Groundwater Data Base. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, B.K.

    1993-04-01

    The Oak Ridge Reservation Hydrology and Geology Study (ORRHAGS) Groundwater Data Base has been compiled to consolidate groundwater data from the three US Department of Energy facilities located on the Oak Ridge Reservation: the Oak Ridge K-25 Site, the Oak Ridge National Laboratory, and the Oak Ridge Y-12 Plant. Each of these facilities maintains its own groundwater and well construction data bases. Data were extracted from the existing data bases, converted to a consistent format, and integrated into the ORRHAGS Groundwater Data Base structures. This data base dictionary describes the data contained in the ORRHAGS Groundwater Data Base and contains information on data base structure, conventions, contents, and use.

  17. Numerical simulation of groundwater flow in the Columbia Plateau Regional Aquifer System, Idaho, Oregon, and Washington

    Science.gov (United States)

    Ely, D. Matthew; Burns, Erick R.; Morgan, David S.; Vaccaro, John J.

    2014-01-01

    A three-dimensional numerical model of groundwater flow was constructed for the Columbia Plateau Regional Aquifer System (CPRAS), Idaho, Oregon, and Washington, to evaluate and test the conceptual model of the system and to evaluate groundwater availability. The model described in this report can be used as a tool by water-resource managers and other stakeholders to quantitatively evaluate proposed alternative management strategies and assess the long‑term availability of groundwater. The numerical simulation of groundwater flow in the CPRAS was completed with support from the Groundwater Resources Program of the U.S. Geological Survey Office of Groundwater.

  18. Enthalpy restoration in geothermal energy processing system

    Science.gov (United States)

    Matthews, Hugh B.

    1983-01-01

    A geothermal deep well energy extraction system is provided of the general type in which solute-bearing hot water is pumped to the earth's surface from a relatively low temperature geothermal source by transferring thermal energy from the hot water to a working fluid for driving a primary turbine-motor and a primary electrical generator at the earth's surface. The superheated expanded exhaust from the primary turbine motor is conducted to a bubble tank where it bubbles through a layer of sub-cooled working fluid that has been condensed. The superheat and latent heat from the expanded exhaust of the turbine transfers thermal energy to the sub-cooled condensate. The desuperheated exhaust is then conducted to the condenser where it is condensed and sub-cooled, whereupon it is conducted back to the bubble tank via a barometric storage tank. The novel condensing process of this invention makes it possible to exploit geothermal sources which might otherwise be non-exploitable.

  19. Distributed parallel computing in stochastic modeling of groundwater systems.

    Science.gov (United States)

    Dong, Yanhui; Li, Guomin; Xu, Haizhen

    2013-03-01

    Stochastic modeling is a rapidly evolving, popular approach to the study of the uncertainty and heterogeneity of groundwater systems. However, the use of Monte Carlo-type simulations to solve practical groundwater problems often encounters computational bottlenecks that hinder the acquisition of meaningful results. To improve the computational efficiency, a system that combines stochastic model generation with MODFLOW-related programs and distributed parallel processing is investigated. The distributed computing framework, called the Java Parallel Processing Framework, is integrated into the system to allow the batch processing of stochastic models in distributed and parallel systems. As an example, the system is applied to the stochastic delineation of well capture zones in the Pinggu Basin in Beijing. Through the use of 50 processing threads on a cluster with 10 multicore nodes, the execution times of 500 realizations are reduced to 3% compared with those of a serial execution. Through this application, the system demonstrates its potential in solving difficult computational problems in practical stochastic modeling. © 2012, The Author(s). Groundwater © 2012, National Ground Water Association.

  20. Environmental impacts of open loop geothermal system on groundwater

    Science.gov (United States)

    Kwon, Koo-Sang; Park, Youngyun; Yun, Sang Woong; Lee, Jin-Yong

    2013-04-01

    Application of renewable energies such as sunlight, wind, rain, tides, waves and geothermal heat has gradually increased to reduce emission of CO2 which is supplied from combustion of fossil fuel. The geothermal energy of various renewable energies has benefit to be used to cooling and heating systems and has good energy efficiency compared with other renewable energies. However, open loop system of geothermal heat pump system has possibility that various environmental problems are induced because the system directly uses groundwater to exchange heat. This study was performed to collect data from many documents such as papers and reports and to summarize environmental impacts for application of open loop system. The environmental impacts are classified into change of hydrogeological factors such as water temperature, redox condition, EC, change of microbial species, well contamination and depletion of groundwater. The change of hydrogeological factors can induce new geological processes such as dissolution and precipitation of some minerals. For examples, increase of water temperature can change pH and Eh. These variations can change saturation index of some minerals. Therefore, dissolution and precipitation of some minerals such as quartz and carbonate species and compounds including Fe and Mn can induce a collapse and a clogging of well. The well contamination and depletion of groundwater can reduce available groundwater resources. These environmental impacts will be different in each region because hydrogeological properties and scale, operation period and kind of the system. Therefore, appropriate responses will be considered for each environmental impact. Also, sufficient study will be conducted to reduce the environmental impacts and to improve geothermal energy efficiency during the period that a open loop system is operated. This work was supported by the Energy Efficiency and Resources of the Korea Institute of Energy Technology Evaluation and Planning

  1. Groundwater quality monitoring well installation for Waste Area Grouping at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program

    International Nuclear Information System (INIS)

    Mortimore, J.A.; Lee, T.A.

    1994-09-01

    This report documents the drilling and installation of 18 groundwater quality monitoring (GQM) wells on the perimeter of Waste Area Grouping (WAG) 11. WAG 11 (White Wing Scrap Yard) is located on the west end of East Fork Ridge between White Wing Road and the Oak Ridge Turnpike. The scrap yard is approximately 25 acres in size. The wells at WAG 11 were drilled and developed between January 1990 and October 1990. These wells were installed to characterize and assess the WAG in accordance with applicable Department of Energy, state, and Environmental Protection Agency regulatory requirements. The wells at WAG 11 were drilled with auger or air rotary rigs. Depending on the hydrogeologic conditions present at each proposed well location, one of four basic installation methods was utilized. Detailed procedures for well construction were specified by the Engineering Division to ensure that the wells would provide water samples representative of the aquifer. To ensure conformance with the specifications, Energy Systems Construction Engineering and ERCE provided continuous oversight of field activities. The purpose of the well installation program was to install GQM wells for groundwater characterization at WAG 11. Data packages produced during installation activities by the ERCE hydrogeologists are an important product of the program. These packages document the well drilling, installation, and development activities and provide valuable data for well sampling and WAG characterization. The forms contained in the packages include predrilling and postdrilling checklists, drilling and construction logs, development and hydraulic conductivity records, and quality control-related documents

  2. A tracking system for groundwater sampling and data transfer schedules

    International Nuclear Information System (INIS)

    Mercier, T.M.

    1990-12-01

    Since groundwater monitoring programs at the Oak Ridge Y-12 Plant have become more complex and varied and as the occasions to respond to internal and external reporting requirements have become more frequent and time constrained, the need to track groundwater sampling activities and data transfer from the analytical laboratories has become imperative. If backlogs can be caught early, resources can be added or reallocated in the field and in the laboratory in a timely manner to ensure reporting deadlines are met. The tracking system discussed in this paper starts with clear definition of the groundwater monitoring program at the facility. This information is input into base datasets at the beginning of the sampling cycle. As the sampling program progresses, information about well sampling dates and data transfer dates is input into the base datasets. From the base program data and the update data, a status report is periodically generated by a computer program which identifies the type and nature of bottle necks encountered during the implementation of the groundwater monitoring program

  3. An approach to evaluate switching overvoltages during power system restoration

    Directory of Open Access Journals (Sweden)

    Sadeghkhani Iman

    2012-01-01

    Full Text Available Transformer switching is one of the important stages during power system restoration. This switching can cause harmonic overvoltages that might damage some equipment and delay power system restoration. Core saturation on the energisation of a transformer with residual flux is a noticeable factor in harmonic overvoltages. This work uses artificial neural networks (ANN in order to estimate the temporary overvoltages (TOVs due to transformer energisation. In the proposed methodology, the Levenberg-Marquardt method is used to train the multilayer perceptron. The developed ANN is trained with the worst case of switching condition, and tested for typical cases. Simulated results for a partial 39-bus New England test system, show the proposed technique can accurately estimate the peak values and durations of switching overvoltages.

  4. Death Valley regional groundwater flow system, Nevada and California-Hydrogeologic framework and transient groundwater flow model

    Science.gov (United States)

    Belcher, Wayne R.; Sweetkind, Donald S.

    2010-01-01

    A numerical three-dimensional (3D) transient groundwater flow model of the Death Valley region was developed by the U.S. Geological Survey for the U.S. Department of Energy programs at the Nevada Test Site and at Yucca Mountain, Nevada. Decades of study of aspects of the groundwater flow system and previous less extensive groundwater flow models were incorporated and reevaluated together with new data to provide greater detail for the complex, digital model. A 3D digital hydrogeologic framework model (HFM) was developed from digital elevation models, geologic maps, borehole information, geologic and hydrogeologic cross sections, and other 3D models to represent the geometry of the hydrogeologic units (HGUs). Structural features, such as faults and fractures, that affect groundwater flow also were added. The HFM represents Precambrian and Paleozoic crystalline and sedimentary rocks, Mesozoic sedimentary rocks, Mesozoic to Cenozoic intrusive rocks, Cenozoic volcanic tuffs and lavas, and late Cenozoic sedimentary deposits of the Death Valley regional groundwater flow system (DVRFS) region in 27 HGUs. Information from a series of investigations was compiled to conceptualize and quantify hydrologic components of the groundwater flow system within the DVRFS model domain and to provide hydraulic-property and head-observation data used in the calibration of the transient-flow model. These studies reevaluated natural groundwater discharge occurring through evapotranspiration (ET) and spring flow; the history of groundwater pumping from 1913 through 1998; groundwater recharge simulated as net infiltration; model boundary inflows and outflows based on regional hydraulic gradients and water budgets of surrounding areas; hydraulic conductivity and its relation to depth; and water levels appropriate for regional simulation of prepumped and pumped conditions within the DVRFS model domain. Simulation results appropriate for the regional extent and scale of the model were provided

  5. Groundwater Monitoring and Engineered Geothermal Systems: The Newberry EGS Demonstration

    Science.gov (United States)

    Grasso, K.; Cladouhos, T. T.; Garrison, G.

    2013-12-01

    Engineered Geothermal Systems (EGS) represent the next generation of geothermal energy development. Stimulation of multiple zones within a single geothermal reservoir could significantly reduce the cost of geothermal energy production. Newberry Volcano in central Oregon represents an ideal location for EGS research and development. As such, the goals of the Newberry EGS Demonstration, operated by AltaRock Energy, Inc., include stimulation of a multiple-zone EGS reservoir, testing of single-well tracers and a demonstration of EGS reservoir viability through flow-back and circulation tests. A shallow, local aquifer supplied the approximately 41,630 m3 (11 million gals) of water used during stimulation of NWG 55-29, a deep geothermal well on the western flank of Newberry Volcano. Protection of the local aquifer is of primary importance to both the Newberry EGS Demonstration and the public. As part of the Demonstration, AltaRock Energy, Inc. has developed and implemented a groundwater monitoring plan to characterize the geochemistry of the local aquifer before, during and after stimulation. Background geochemical conditions were established prior to stimulation of NWG 55-29, which was completed in 2012. Nine sites were chosen for groundwater monitoring. These include the water supply well used during stimulation of NWG 55-29, three monitoring wells, three domestic water wells and two hot seeps located in the Newberry Caldera. Together, these nine monitoring sites represent up-, down- and cross-gradient locations. Groundwater samples are analyzed for 25 chemical constituents, stable isotopes, and geothermal tracers used during stimulation. In addition, water level data is collected at three monitoring sites in order to better characterize the effects of stimulation on the shallow aquifer. To date, no significant geochemical changes and no geothermal tracers have been detected in groundwater samples from these monitoring sites. The Newberry EGS Demonstration groundwater

  6. Technetium and neptunium reactions in basalt/groundwater systems

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Kelmers, A.D.; Kessler, J.H.; Clark, R.J.; Johnson, J.S. Jr.; Young, G.C.; Case, F.I.; Westmoreland, C.G.

    1985-01-01

    Sorption isotherms and apparent concentration limits for Tc(VII) and Np(V) for a variety of groundwater/basalt systems were determined using Grande Ronde basalt samples representative of the Hanford Site candidate high-level waste repository. Under oxic redox conditions (air present), little or no sorption of technetium was observed; neptunium exhibited low to moderate sorption ratios. Under anoxic redox conditions (oxygen-free), low to moderate sorption of technetium was often observed, but the extent of sorption was highly dependent upon the groundwater composition and the method of pretreatment (if any) of the basalt. Sorption isotherms for technetium under reducing redox conditions (hydrazine added) indicate an apparent concentration limit of approximately 10 -6 mol/l Tc. No apparent concentration limit was found for neptunium for concentrations in groundwater up to 10 -6 mol/l and 8 x 10 -7 mol/l under oxic and reducing (hydrazine added) redox conditions, respectively. Valence control and valence analysis experiments suggest that the sorption or precipitation of Tc and Np from groundwater in the presence of basalt may result from a heterogeneous reaction occurring on the surface of the basalt. One of the critical factors of this reduction reaction appears to be the accessibility of the reactive ferrous iron component of the basalt. The laboratory simulation of groundwater redox conditions representative of the repository environment through the use of solution phase redox reagents is of questionable validity, and information obtained by such experimental methods may not be defensible for site performance assessment calculations. Anoxic experiments conducted in an argon-filled glove box appear better suited for the laboratory simulation of in situ redox conditions. 15 references, 6 figures

  7. Technetium and neptunium reactions in basalt/groundwater systems

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Kelmers, A.D.; Kessler, J.H.; Clark, R.J.; Johnson, J.S. Jr.; Young, G.C.; Case, F.I.; Westmoreland, C.G.; Florida State Univ., Tallahassee)

    1984-01-01

    Sorption isotherms and apparent concentration limits for Tc(VII) and Np(V) for a variety of groundwater/basalt systems were determined using Grande Ronde basalt samples representative of the Hanford Site candidate high-level waste repository. Under oxic redox conditions (air present), little or no sorption of technetium was observed; neptunium exhibited low to moderate sorption ratios. Under anoxic redox conditions (oxygen-free), low to moderate sorption of technetium was often observed, but the extent of sorption was highly dependent upon the groundwater composition and the method of pretreatment (if any) of the basalt. Sorption isotherms for technetium under reducing redox conditions (hydrazine added) indicate an apparent concentration limit of approximately 10 -6 mol/L Tc. No apparent concentration limit was found for neptunium for concentrations in groundwater up to approx. 10 -6 mol/L and 8 x 10 -7 mol/L under oxic and reducing (hydrazine added) redox conditions, respectively. Valence control and valence analysis experiments suggest that the sorption or precipitation of Tc and Np from groundwater in the presence of basalt may result from a heterogeneous reaction occurring on the surface of the basalt. One of the critical factors of this reduction reaction appears to be the accessibility of the reactive ferrous iron component of the basalt. The laboratory simulation of groundwater redox conditions representative of the repository environment through the use of solution phase redox reagents is of questionable validity, and information obtained by such experimental methods may not be defensible for site performance assessment calculations. Anoxic experiments conducted in an argon-filled glove box appear better suited for the laboratory simulation of in situ redox conditions. 15 refs., 6 tabs

  8. Evaluation of Background Mercury Concentrations in the SRS Groundwater System

    International Nuclear Information System (INIS)

    Looney, B.B.

    1999-01-01

    Mercury analyses associated with the A-01 Outfall have highlighted the importance of developing an understanding of mercury in the Savannah River Site groundwater system and associated surface water streams. This activity is critical based upon the fact that the EPA Ambient Water Quality Criteria (AWQC) for this constituent is 0.012mg/L, a level that is well below conventional detection limits of 0.1 to 0.2 mg/L. A first step in this process is obtained by utilizing the existing investment in groundwater mercury concentrations (20,242 records) maintained in the SRS geographical information management system (GIMS) database. Careful use of these data provides a technically defensible initial estimate for total recoverable mercury in background and contaminated SRS wells

  9. Development, Testing, and Application of a Coupled Hydrodynamic Surface-Water/Groundwater Model (FTLOADDS) with Heat and Salinity Transport in the Ten Thousand Islands/Picayune Strand Restoration Project Area, Florida

    Science.gov (United States)

    Swain, Eric D.; Decker, Jeremy D.

    2009-01-01

    A numerical model application was developed for the coastal area inland of the Ten Thousand Islands (TTI) in southwestern Florida using the Flow and Transport in a Linked Overland/Aquifer Density-Dependent System (FTLOADDS) model. This model couples a two-dimensional dynamic surface-water model with a three-dimensional groundwater model, and has been applied to several locations in southern Florida. The model application solves equations for salt transport in groundwater and surface water, and also simulates surface-water temperature using a newly enhanced heat transport algorithm. One of the purposes of the TTI application is to simulate hydrologic factors that relate to habitat suitability for the West Indian Manatee. Both salinity and temperature have been shown to be important factors for manatee survival. The inland area of the TTI domain is the location of the Picayune Strand Restoration Project, which is designed to restore predevelopment hydrology through the filling and plugging of canals, construction of spreader channels, and the construction of levees and pump stations. The effects of these changes are simulated to determine their effects on manatee habitat. The TTI application utilizes a large amount of input data for both surface-water and groundwater flow simulations. These data include topography, frictional resistance, atmospheric data including rainfall and air temperature, aquifer properties, and boundary conditions for tidal levels, inflows, groundwater heads, and salinities. Calibration was achieved by adjusting the parameters having the largest uncertainty: surface-water inflows, the surface-water transport dispersion coefficient, and evapotranspiration. A sensitivity analysis did not indicate that further parameter changes would yield an overall improvement in simulation results. The agreement between field data from GPS-tracked manatees and TTI application results demonstrates that the model can predict the salinity and temperature

  10. Genetic analysis of fertility restoration under CGMS system in rice ...

    Indian Academy of Sciences (India)

    restore complete fertility of a certain CMS line by various restorer lines (Tan et ... Keywords. rice; heterosis; three-way test cross; fertility restoration genetics. Journal of ..... plants indicating a strong genetic load of maintenance in. DE2. Table 8.

  11. Death Valley regional ground-water flow system, Nevada and California -- hydrogeologic framework and transient ground-water flow model

    Science.gov (United States)

    Belcher, Wayne R.

    2004-01-01

    A numerical three-dimensional (3D) transient ground-water flow model of the Death Valley region was developed by the U.S. Geological Survey for the U.S. Department of Energy programs at the Nevada Test Site and at Yucca Mountain, Nevada. Decades of study of aspects of the ground-water flow system and previous less extensive ground-water flow models were incorporated and reevaluated together with new data to provide greater detail for the complex, digital model. A 3D digital hydrogeologic framework model (HFM) was developed from digital elevation models, geologic maps, borehole information, geologic and hydrogeologic cross sections, and other 3D models to represent the geometry of the hydrogeologic units (HGUs). Structural features, such as faults and fractures, that affect ground-water flow also were added. The HFM represents Precambrian and Paleozoic crystalline and sedimentary rocks, Mesozoic sedimentary rocks, Mesozoic to Cenozoic intrusive rocks, Cenozoic volcanic tuffs and lavas, and late Cenozoic sedimentary deposits of the Death Valley Regional Ground-Water Flow System (DVRFS) region in 27 HGUs. Information from a series of investigations was compiled to conceptualize and quantify hydrologic components of the ground-water flow system within the DVRFS model domain and to provide hydraulic-property and head-observation data used in the calibration of the transient-flow model. These studies reevaluated natural ground-water discharge occurring through evapotranspiration and spring flow; the history of ground-water pumping from 1913 through 1998; ground-water recharge simulated as net infiltration; model boundary inflows and outflows based on regional hydraulic gradients and water budgets of surrounding areas; hydraulic conductivity and its relation to depth; and water levels appropriate for regional simulation of prepumped and pumped conditions within the DVRFS model domain. Simulation results appropriate for the regional extent and scale of the model were

  12. Groundwater quality mapping using geographic information system ...

    African Journals Online (AJOL)

    Spatial variations in ground water quality in the corporation area of Gulbarga City located in the northern part of Karnataka State, India, have been studied using geographic information system (GIS) technique. GIS, a tool which is used for storing, analyzing and displaying spatial data is also used for investigating ground ...

  13. Hydrochemistry and Isotope Hydrology for Groundwater Sustainability of the Coastal Multilayered Aquifer System (Zhanjiang, China

    Directory of Open Access Journals (Sweden)

    Pengpeng Zhou

    2017-01-01

    Full Text Available Groundwater sustainability has become a critical issue for Zhanjiang (China because of serious groundwater level drawdown induced by overexploitation of its coastal multilayered aquifer system. It is necessary to understand the origins, material sources, hydrochemical processes, and dynamics of the coastal groundwater in Zhanjiang to support its sustainable management. To this end, an integrated analysis of hydrochemical and isotopic data of 95 groundwater samples was conducted. Hydrochemical analysis shows that coastal groundwater is fresh; however, relatively high levels of Cl−, Mg2+, and total dissolved solid (TDS imply slight seawater mixing with coastal unconfined groundwater. Stable isotopes (δ18O and δ2H values reveal the recharge sources of groundwater in the multilayered aquifer system. The unconfined groundwater originates from local modern precipitation; the confined groundwater in mainland originates from modern precipitation in northwestern mountain area, and the confined groundwater in Donghai and Leizhou is sourced from rainfall recharge during an older period with a colder climate. Ionic relations demonstrate that silicate weathering, carbonate dissolutions, and cation exchange are the primary processes controlling the groundwater chemical composition. Declining trends of groundwater level and increasing trends of TDS of the confined groundwater in islands reveal the landward extending tendency of the freshwater-seawater mixing zone.

  14. Understanding socio-groundwater systems: framework, toolbox, and stakeholders’ efforts for analysis and monitoring groundwater resources

    OpenAIRE

    López Maldonado, Yolanda Cristina

    2018-01-01

    Groundwater, the predominant accessible reservoir of freshwater storage on Earth, plays an important role as a human-natural life sustaining resource. In recent decades there has been an increasing concern that human activities are placing too much pressure on the resource, affecting the health of the ecosystem. However, because groundwater it is out of sight, its monitoring on both global and local scales is challenging. In the field of groundwater monitoring, modelling tools have been devel...

  15. Environmental Restoration Program quality system requirements for the Hanford Site

    International Nuclear Information System (INIS)

    Cote, R.F.

    1993-11-01

    This document defines the quality system requirements for the US Department of Energy, Richland Operations Office, Environmental Restoration Program at the Hanford Site. The Quality System Requirements (OSR) for the Hanford Site integrates quality assurance requirements from the US Department of Energy Orders, the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement), and applicable industry standards into a single source document for the development of quality systems applicable to the Environmental Restoration Program activities. This document, based on fifteen criteria and divided intro three parts, provides user organizations with the flexibility to incorporate only those criteria and parts applicable to their specific scopes of work. The requirements of this document shall be applied to activities that affect quality based on a graded approach that takes into consideration the risk inherent in, as well as the importance of, specific items, services, and activities in terms of meeting ER Program objectives and customer expectations. The individual quality systems developed in accordance with this document are intended to provide an integrated management control system that assures the conduct of ER Program activities in a manner that protects human health and the environment

  16. Systems approach to tracer data in groundwater hydrology

    International Nuclear Information System (INIS)

    Saxena, R.K.

    1977-01-01

    A brief review of current mathematical methods for the analysis of tracer data in groundwater hydrology has been given. The description of the hydrological cycle as a whole or in part, by a system (compartment) or sub-system under linear and stationary conditions is discussed. Basic concepts of transit time, residence time, their distributions in time and response characteristics of a system are outlined. From the knowledge of tracer input, output and systems response function for a generalised system, reservoir capacity and storage for given period can be estimated. Use of a time series model for environmental tracer data in discreet time scale aimed at the solution of hydrological problems e.g. mean transit time and reservoir capacity is also explored. It is concluded that the combination of tracer data with systems approach can go a long way in the study of some complex hydrological problems. (author)

  17. Groundwater Quality Sampling and Analysis Plan for Environmental Monitoring Waste Area Grouping 6 at Oak Ridge National Laboratory. Environmental Restoration Program

    International Nuclear Information System (INIS)

    1995-09-01

    This Sampling and Analysis Plan addresses groundwater quality sampling and analysis activities that will be conducted in support of the Environmental Monitoring Plan for Waste Area Grouping (WAG) 6. WAG 6 is a shallow-burial land disposal facility for low-level radioactive waste at the Oak Ridge National Laboratory, a research facility owned by the US Department of Energy and managed by Martin Marietta Energy Systems, Inc. (Energy Systems). Groundwater sampling will be conducted by Energy Systems at 45 wells within WAG 6. The samples will be analyzed for various organic, inorganic, and radiological parameters. The information derived from the groundwater quality monitoring, sampling, and analysis will aid in evaluating relative risk associated with contaminants migrating off-WAG, and also will fulfill Resource Conservation and Recovery Act (RCRA) interim permit monitoring requirements. The sampling steps described in this plan are consistent with the steps that have previously been followed by Energy Systems when conducting RCRA sampling

  18. Resilience assessment of interdependent infrastructure systems: With a focus on joint restoration modeling and analysis

    International Nuclear Information System (INIS)

    Ouyang, Min; Wang, Zhenghua

    2015-01-01

    As infrastructure systems are highly interconnected, it is crucial to analyze their resilience with the consideration of their interdependencies. This paper adapts an existing resilience assessment framework for single systems to interdependent systems and mainly focuses on modeling and resilience contribution analysis of multi-systems’ joint restoration processes, which are seldom addressed in the literature. Taking interdependent power and gas systems in Houston, Texas, USA under hurricane hazards as an illustrative exmaple, five types of joint restoration stategies are proposed, including random restoration strategy RS 1 , independent restoration strategy RS 2 , power first and gas second restoration strategy RS 3 , gas aimed restoration strategy RS 4 , and power and gas compromised restoration strategy RS 5 . Results show that under limited restoration resources, RS 1 produces the least resilience for both systems, RS 2 and RS 3 both generates the largest power system resilience while RS 4 is the best for the gas system; and if quantifying the total resilience as the evenly weighted sum of two systems’ individual resilience, RS 5 produces the largest total resilience. The proposed method can help decision makers search optimum joint restoration strategy, which can significantly enhance both systems’ resilience. - Highlights: • We propose a method to assess resilience of interdependent infrastructure systems. • We consider unidirectional interdependencies from power system to gas system. • Multi-systems’ restoration processes are solved by using genetic algorithm. • Effectiveness of five restoration strategies are compared and analyzed. • Interdependency-based strategies produce the largest total resilience

  19. Simulation of the regional groundwater-flow system of the Menominee Indian Reservation, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.; Dunning, Charles P.

    2015-01-01

    A regional, two-dimensional, steady-state groundwater-flow model was developed to simulate the groundwater-flow system and groundwater/surface-water interactions within the Menominee Indian Reservation. The model was developed by the U.S. Geological Survey (USGS), in cooperation with the Menominee Indian Tribe of Wisconsin, to contribute to the fundamental understanding of the region’s hydrogeology. The objectives of the regional model were to improve understanding of the groundwater-flow system, including groundwater/surface-water interactions, and to develop a tool suitable for evaluating the effects of potential regional water-management programs. The computer code GFLOW was used because of the ease with which the model can simulate groundwater/surface-water interactions, provide a framework for simulating regional groundwater-flow systems, and be refined in a stepwise fashion to incorporate new data and simulate groundwater-flow patterns at multiple scales. Simulations made with the regional model reproduce groundwater levels and stream base flows representative of recent conditions (1970–2013) and illustrate groundwater-flow patterns with maps of (1) the simulated water table and groundwater-flow directions, (2) probabilistic areas contributing recharge to high-capacity pumped wells, and (3) estimation of the extent of infiltrated wastewater from treatment lagoons.

  20. Investigation of ground-water contamination at a drainage ditch, Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, 2005–06

    Science.gov (United States)

    Vroblesky, Don A.; Casey, Clifton C.

    2007-01-01

    The U.S. Geological Survey, in cooperation with the Naval Facilities Engineering Command Southeast, used newly developed sampling methods to investigate ground-water contamination by chlorobenzenes beneath a drainage ditch on the southwestern side of Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, during 2005-06. The drainage ditch, which is a potential receptor for ground-water contaminants from Installation Restoration Site 4, intermittently discharges water to Corpus Christi Bay. This report uses data from a new type of pore-water sampler developed for this investigation and other methods to examine the subsurface contamination beneath the drainage ditch. Analysis of ground water from the samplers indicated that chlorobenzenes (maximum detected concentration of 160 micrograms per liter) are present in the ground water beneath the ditch. The concentrations of dissolved oxygen in the samples (less than 0.05-0.4 milligram per liter) showed that the ground water beneath and near the ditch is anaerobic, indicating that substantial chlorobenzene biodegradation in the aquifer beneath the ditch is unlikely. Probable alternative mechanisms of chlorobenzene removal in the ground water beneath the drainage ditch include sorption onto the organic-rich sediment and contaminant depletion by cattails through uptake, sorption, and localized soil aeration.

  1. Earthquake effects on groundwater systems: an introductory review

    International Nuclear Information System (INIS)

    1988-09-01

    This report presents an introductory review of the potential effects of earthquakes on groundwater systems with respect to the performance of underground repositories for radioactive waste in Britain. An approach to modelling these effects within the scope of general environmental simulation codes is presented. The relevant literature is reviewed and it is concluded that, although pertinent information exists, no clear relationship between seismic intensity and the degree of fracturing has been established. Recommendations are made for further work on fracture development to complement existing research into the effects of long-term changes on the integrity of radioactive waste disposal facilities. (author)

  2. A Guide for Using the Transient Ground-Water Flow Model of the Death Valley Regional Ground-Water Flow System, Nevada and California

    Energy Technology Data Exchange (ETDEWEB)

    Joan B. Blainey; Claudia C. Faunt, and Mary C. Hill

    2006-05-16

    This report is a guide for executing numerical simulations with the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California using the U.S. Geological Survey modular finite-difference ground-water flow model, MODFLOW-2000. Model inputs, including observations of hydraulic head, discharge, and boundary flows, are summarized. Modification of the DVRFS transient ground-water model is discussed for two common uses of the Death Valley regional ground-water flow system model: predictive pumping scenarios that extend beyond the end of the model simulation period (1998), and model simulations with only steady-state conditions.

  3. Microleakage of hydrophilic adhesive systems in Class V composite restorations.

    Science.gov (United States)

    Amaral, C M; Hara, A T; Pimenta, L A; Rodrigues, A L

    2001-02-01

    To investigate the microleakage of four hydrophilic adhesive systems: one "multiple-bottles" (Scotchbond Multi-Purpose Plus); two "one-bottle" (Single Bond, Stae); and one self-etching (Etch & Prime 3.0). 120 bovine incisor teeth were divided into four groups (n = 30) and Class V cavities were prepared at the cemento-enamel junction. The cavities were restored with the adhesive systems and with Z100 composite. The teeth were thermocycled 1,000 times between 5+/-2 degrees C and 55+/-2 degrees C with a dwell time of 1 min, and then placed in a 2% methylene blue dye (pH 7.0) for 4 hrs, washed and sectioned vertically through the center of the restorations. The qualitative evaluation was made by three examiners who distributed pre-established scores (0-4) for each tooth using a stereomicroscope at x30 magnification. In enamel margins little microleakage was observed and the Kruskal-Wallis analysis did not show differences. In dentin margins the Kruskal-Wallis and multiple comparison analyses were applied: microleakage was significantly greater with Stae (median 3) and Scotchbond MP Plus (median 4). Single Bond (median 1) and Etch & Prime 3.0 (median 2) showed the best results in dentin margins, and the statistical analysis did not demonstrate differences in microleakage among these groups.

  4. Development of Multi-Functional Voltage Restore System

    Science.gov (United States)

    Suzuki, Satoshi; Ueda, Yoshinobu; Koganezawa, Takehisa; Ogihara, Yoshinori; Mori, Kenjiro; Fukazu, Naoaki

    Recently, with the dawn of the electric deregulation, the installation of distributed generation with power electronics device has grown. This current causes a greater concern of power quality, primarily voltage disturbance for power companies, and their interest in power quality is peaking. Utilities are also interested in keeping their customers satisfied, as well as keeping them on-line and creating more revenue for the utility. As a countermeasure against the above surroundings, a variety type of devices based on power electronics has been developed to protect customers' load from power line voltage disturbance. One of them is the series type voltage restore. The series device is an active device, designed to provide a pure sinusoidal load voltage at all times, correcting voltage disturbance. Series type device compensates for voltage anomalies by inserting the ‘missing’ voltage onto the line through insertion transformer and inverter. This paper shows the setting guideline of target level to compensate voltage disturbance, that is, voltage dip, voltage harmonics, voltage imbalance and voltage flicker, and the design approach of the prototype of series voltage restores to accomplish the required compensation level. The prototype system gives satisfactory compensation performance through evaluation tests, which confirm the validity and effectiveness of the system.

  5. Geochemical studies of groundwater systems of semiarid Yola area ...

    African Journals Online (AJOL)

    This was to determine the process controlling the water chemistry and to assess the ... for the deep groundwater and Na+-Cl- for the surface water bodies. ... Groundwater samples from the shallow groundwater indicate pH values (6.10 to 7.08) ...

  6. Aquifer restoration system improvement using an acid fluid purge

    International Nuclear Information System (INIS)

    Hodder, E.A.; Peck, C.A.

    1992-01-01

    The implementation of a water pump acid purge procedure at a free-phase liquid hydrocarbon recovery site has increased water pump operational run times and improved the effectiveness of the aquifer restoration effort. Before introduction of this technique, pumps at some locations would fail within 14 days of operation due to CaSO 4 .2H 2 O (calcium sulfate) precipitate fouling. After acid purge implementation at these locations, pump operational life improved to an average of over 110 days. Other locations, where pump failures would occur within one month, were improved to approximately six months of operation. The increase in water pump run time has also improved the liquid hydrocarbon recovery rate by 2,000 gallons per day; representing a 20% increase for the aquifer restoration system. Other concepts tested in attempts to prolong pump life included: specially designed electric submersible pumps, submersible pump shrouds intended to reduce the fluid pressure shear that enhances CaSO 4 .2H 2 O precipitation, and high volume pneumatic gas lift pumps. Due to marginal pump life improvement or other undesirable operational features, these concepts were primarily ineffective. The purge apparatus utilizes an acid pump, hose, and discharge piping to deliver the solution directly into the inlet of an operating water pump. The water pumps used for this activity require stainless steel construction with Teflon or other acid resistant bearings and seals. Purges are typically conducted before sudden discharge pressure drops (greater than 15 psig) occur for the operating water pump. Depending on volume of precipitate accumulation and pump type, discharge pressure is restored after introduction of 10 to 40 gallons of hydrochloric acid solution. The acid purge procedure outlined herein eliminates operational downtime and does not require well head pump removal and the associated costs of industry cleaning procedures

  7. Groundwater flow processes and mixing in active volcanic systems: the case of Guadalajara (Mexico)

    Science.gov (United States)

    Hernández-Antonio, A.; Mahlknecht, J.; Tamez-Meléndez, C.; Ramos-Leal, J.; Ramírez-Orozco, A.; Parra, R.; Ornelas-Soto, N.; Eastoe, C. J.

    2015-09-01

    Groundwater chemistry and isotopic data from 40 production wells in the Atemajac and Toluquilla valleys, located in and around the Guadalajara metropolitan area, were determined to develop a conceptual model of groundwater flow processes and mixing. Stable water isotopes (δ2H, δ18O) were used to trace hydrological processes and tritium (3H) to evaluate the relative contribution of modern water in samples. Multivariate analysis including cluster analysis and principal component analysis were used to elucidate distribution patterns of constituents and factors controlling groundwater chemistry. Based on this analysis, groundwater was classified into four groups: cold groundwater, hydrothermal groundwater, polluted groundwater and mixed groundwater. Cold groundwater is characterized by low temperature, salinity, and Cl and Na concentrations and is predominantly of Na-HCO3-type. It originates as recharge at "La Primavera" caldera and is found predominantly in wells in the upper Atemajac Valley. Hydrothermal groundwater is characterized by high salinity, temperature, Cl, Na and HCO3, and the presence of minor elements such as Li, Mn and F. It is a mixed-HCO3 type found in wells from Toluquilla Valley and represents regional flow circulation through basaltic and andesitic rocks. Polluted groundwater is characterized by elevated nitrate and sulfate concentrations and is usually derived from urban water cycling and subordinately from agricultural return flow. Mixed groundwaters between cold and hydrothermal components are predominantly found in the lower Atemajac Valley. Twenty-seven groundwater samples contain at least a small fraction of modern water. The application of a multivariate mixing model allowed the mixing proportions of hydrothermal fluids, polluted waters and cold groundwater in sampled water to be evaluated. This study will help local water authorities to identify and dimension groundwater contamination, and act accordingly. It may be broadly applicable to

  8. Knowledge base to develop expert system prototype for predicting groundwater pollution from nitrogen fertilizer

    International Nuclear Information System (INIS)

    Ta-oun, M.; Daud, M.; Bardaie, M.Z.; Jusop, S.

    1999-01-01

    An expert system for prediction the impact of nitrogen fertilizer on groundwater pollution potential was established by using CLIPS (NASA's Jonson Space Centre). The knowledge base could be extracted from FAO reports, ministry of agriculture and rural development Malaysia report, established literature and domain expert for preparing an expert system skeleton. An expert system was used to correlate the availability of nitrogen fertilizer with the vulnerability of groundwater to pollution in Peninsula Malaysia and to identify potential groundwater quality problems. An n-fertilizer groundwater pollution potential index produced b using the vulnerability of groundwater to pollution yields a more accurate screening toll for identifying potential pollution problems than by considering vulnerability alone. An expert system can predict the groundwater pollution potential under several conditions of agricultural activities and existing environments. (authors)

  9. Assessing the relative bioavailability of DOC in regional groundwater systems

    Science.gov (United States)

    Chapelle, Francis H.; Bradley, Paul M.; Journey, Celeste A.; McMahon, Peter B.

    2013-01-01

    It has been hypothesized that the degree to which a hyperbolic relationship exists between concentrations of dissolved organic carbon (DOC) and dissolved oxygen (DO) in groundwater may indicate the relative bioavailability of DOC. This hypothesis was examined for 73 different regional aquifers of the United States using 7745 analyses of groundwater compiled by the National Water Assessment (NAWQA) program of the U.S. Geological Survey. The relative reaction quotient (RRQ), a measure of the curvature of DOC concentrations plotted versus DO concentrations and regressed to a decaying hyperbolic equation, was used to assess the relative bioavailability of DOC. For the basalt aquifer of Oahu, Hawaii, RRQ values were low (0.0013 mM−2), reflecting a nearly random relationship between DOC and DO concentrations. In contrast, on the island of Maui, treated sewage effluent injected into a portion of the basalt aquifer resulted in pronounced hyperbolic DOC-DO behavior and a higher RRQ (142 mM−2). RRQ values for the 73 aquifers correlated positively with mean concentrations of ammonia, dissolved iron, and manganese, and correlated negatively with mean pH. This indicates that greater RRQ values are associated with greater concentrations of the final products of microbial reduction reactions. RRQ values and DOC concentrations were negatively correlated with the thickness of the unsaturated zone (UNST) and depth to the top of the screened interval. Finally, RRQ values were positively correlated with mean annual precipitation (MAP), and the highest observed RRQ values were associated with aquifers receiving MAP rates ranging between 900 and 1300 mm/year. These results are uniformly consistent with the hypothesis that the hyperbolic behavior of DOC-DO plots, as quantified by the RRQ metric, can be an indicator of relative DOC bioavailability in groundwater systems.

  10. Assessing the relative bioavailability of DOC in regional groundwater systems.

    Science.gov (United States)

    Chapelle, Francis H; Bradley, Paul M; Journey, Celeste A; McMahon, Peter B

    2013-01-01

    It has been hypothesized that the degree to which a hyperbolic relationship exists between concentrations of dissolved organic carbon (DOC) and dissolved oxygen (DO) in groundwater may indicate the relative bioavailability of DOC. This hypothesis was examined for 73 different regional aquifers of the United States using 7745 analyses of groundwater compiled by the National Water Assessment (NAWQA) program of the U.S. Geological Survey. The relative reaction quotient (RRQ), a measure of the curvature of DOC concentrations plotted versus DO concentrations and regressed to a decaying hyperbolic equation, was used to assess the relative bioavailability of DOC. For the basalt aquifer of Oahu, Hawaii, RRQ values were low (0.0013 mM(-2)), reflecting a nearly random relationship between DOC and DO concentrations. In contrast, on the island of Maui, treated sewage effluent injected into a portion of the basalt aquifer resulted in pronounced hyperbolic DOC-DO behavior and a higher RRQ (142 mM(-2)). RRQ values for the 73 aquifers correlated positively with mean concentrations of ammonia, dissolved iron, and manganese, and correlated negatively with mean pH. This indicates that greater RRQ values are associated with greater concentrations of the final products of microbial reduction reactions. RRQ values and DOC concentrations were negatively correlated with the thickness of the unsaturated zone (UNST) and depth to the top of the screened interval. Finally, RRQ values were positively correlated with mean annual precipitation (MAP), and the highest observed RRQ values were associated with aquifers receiving MAP rates ranging between 900 and 1300 mm/year. These results are uniformly consistent with the hypothesis that the hyperbolic behavior of DOC-DO plots, as quantified by the RRQ metric, can be an indicator of relative DOC bioavailability in groundwater systems. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

  11. Numerical simulation of groundwater flow for the Yakima River basin aquifer system, Washington

    Science.gov (United States)

    Ely, D.M.; Bachmann, M.P.; Vaccaro, J.J.

    2011-01-01

    A regional, three-dimensional, transient numerical model of groundwater flow was constructed for the Yakima River basin aquifer system to better understand the groundwater-flow system and its relation to surface-water resources. The model described in this report can be used as a tool by water-management agencies and other stakeholders to quantitatively evaluate proposed alternative management strategies that consider the interrelation between groundwater availability and surface-water resources.

  12. Standing phase angle reduction for power system restoration

    Energy Technology Data Exchange (ETDEWEB)

    Hazarika, D. [Assam Engineering College (India). Electrical Engineering Dept.; Sinha, A.K. [IIT Khargpur (India). Electrical Engineering Dept.

    1998-01-01

    The paper describes a methodology for the reduction of standing phase angle (SPA) difference between two buses of a power system, which is essential before interconnecting a line between two buses. This problem is encountered normally during restoration operations of a power system. For this purpose, the standing phase angle difference between two specific buses is represented in terms of sensitivity factors associated with the change in real power injections at the buses. To arrive at the desired standing phase angle difference between two buses, the modified contribution at generation/load buses have been evaluated based on 'higher the sensitivity higher the participation' logic. This methodology acts as a direct help to reduce excessive SPA difference between two buses to an acceptable limit, which otherwise requires regulation of various generation levels on a trial and error basis. (author)

  13. Restoration of groundwater quality after in situ uranium leaching. Open file report (final) October 1977-August 1979

    International Nuclear Information System (INIS)

    Riding, J.R.; Rosswog, F.J.

    1979-08-01

    In situ solution mining of uranium has several environmental advantages over other mining techniques. The leaching of uranium, however, alters the ground water in the aquifer where the leaching occurs. A requirement of the mining technique is the control of objectionable materials that are introduced into the water. This report reviews the state of the art in restoring ground water quality. Current restoration practices discussed include disposal wells and solar evaporation ponds. Sweeping techniques by producing water flow from all wells during restoration and recirculating techniques by recharging water from a surface purification plant are evaluated. Methods for predicting the effectiveness and costs of current methods are presented. Possible alternatives for restoration of the ground water quality are described

  14. Linking Groundwater Use and Stress to Specific Crops Using the Groundwater Footprint in the Central Valley and High Plains Aquifer Systems, U.S.

    Science.gov (United States)

    Wada, Y.; Esnault, L.; Gleeson, T.; Heinke, J.; Gerten, D.; Flanary, E.; Bierkens, M. F.; Van Beek, L. P.

    2014-12-01

    A number of aquifers worldwide are being depleted, mainly by agricultural activities, yet groundwater stress has not been explicitly linked to specific agricultural crops. Using the newly-developed concept of the groundwater footprint (the area required to sustain groundwater use and groundwater-dependent ecosystem services), we develop a methodology to derive crop-specific groundwater footprints. We illustrate this method by calculating high resolution groundwater footprint estimates of crops in two heavily used aquifer systems: the Central Valley and High Plains, U.S. In both aquifer systems, hay and haylage, corn and cotton have the largest groundwater footprints, which highlights that most of the groundwater stress is induced by crops meant for cattle feed. Our results are coherent with other studies in the High Plains but suggest lower groundwater stress in the Central Valley, likely due to artificial recharge from surface water diversions which were not taken into account in previous estimates. Uncertainties of recharge and irrigation application efficiency contribute the most to the total relative uncertainty of the groundwater footprint to aquifer area ratios. Our results and methodology will be useful for hydrologists, water resource managers, and policy makers concerned with which crops are causing the well-documented groundwater stress in semiarid to arid agricultural regions around the world.

  15. Pathogen transport in groundwater systems: contrasts with traditional solute transport

    Science.gov (United States)

    Hunt, Randall J.; Johnson, William P.

    2017-06-01

    Water quality affects many aspects of water availability, from precluding use to societal perceptions of fit-for-purpose. Pathogen source and transport processes are drivers of water quality because they have been responsible for numerous outbreaks resulting in large economic losses due to illness and, in some cases, loss of life. Outbreaks result from very small exposure (e.g., less than 20 viruses) from very strong sources (e.g., trillions of viruses shed by a single infected individual). Thus, unlike solute contaminants, an acute exposure to a very small amount of contaminated water can cause immediate adverse health effects. Similarly, pathogens are larger than solutes. Thus, interactions with surfaces and settling become important even as processes important for solutes such as diffusion become less important. These differences are articulated in "Colloid Filtration Theory", a separate branch of pore-scale transport. Consequently, understanding pathogen processes requires changes in how groundwater systems are typically characterized, where the focus is on the leading edges of plumes and preferential flow paths, even if such features move only a very small fraction of the aquifer flow. Moreover, the relatively short survival times of pathogens in the subsurface require greater attention to very fast (solute transport mechanisms discussed here, a more encompassing view of water quality and source water protection is attained. With this more holistic view and theoretical understanding, better evaluations can be made regarding drinking water vulnerability and the relation between groundwater and human health.

  16. 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.

  17. Modeling and simulation of dynamic voltage restorer in power system

    International Nuclear Information System (INIS)

    Abdel Aziz, M.A.A.M.

    2012-01-01

    There are many loads subjected to several Power Quality Problems such as voltage sags/swells, unbalance, harmonics distortion, and short interruption. These loads encompass a wide range of equipment which are very sensitive to voltage disturbances. The Dynamic Voltage Restorer (DVR) has recently been introduced to protect sensitive loads from voltage sags and other voltage disturbances in addition to this, it mitigates current harmonics distortion. It is a series connected power electronic based device. It is considered as one of the most efficient and effective solutions. Its appeal includes smaller size and fast dynamic response to disturbances. This work describes a proposal of the DVR to improve power quality distribution (medium voltage) system. The control of the compensation voltage and harmonics cancellation in the DVR is based on Adaptive Noise Canceling (ANC) technique. Simulation results carried out by PSCAD/EMTDC to investigate the performance of the proposed method.

  18. Preliminary design of a priority system for DOE environmental restoration

    International Nuclear Information System (INIS)

    Longo, T.P.; Whitfield, R.P.; Cotton, T.A.; Merkhofer, M.W.

    1990-01-01

    For over 40 yr, the US Department of Energy (DOE) and predecessor agencies have managed the production of nuclear materials and weapons for national defense. Operations at facilities in ∼20 states have produced hundreds, perhaps thousands, of contaminated sites. The DOE is committed to cleaning up these sites over a 30-yr period. The cleanup will cost tens of billions of dollars. To assist in the process of formulating and allocating the budget for cleaning up these sites, DOE is developing a risk-based priority system. The system will be a formal decision-aiding tool addressing health and safety risks as well as social, technical, economic, and policy issues. It will ensure that funding decisions reflect the primary goals of protecting public health and the environment and complying with regulatory requirements and agreements. The system also will ensure that decisions are made in a technically defensible and even-handed manner. The primary purpose of the system is to provide information useful for two types of DOE budgetary decisions. One is identifying desirable budget levels and formulating DOE's annual budget request. The other is allocating in the most effective way the funds appropriated by Congress. The priority system will initially apply to DOE's environmental restoration (ER) program, which involves assessing, cleaning up, and closing inactive waste sites and surplus facilities

  19. Joint image restoration and location in visual navigation system

    Science.gov (United States)

    Wu, Yuefeng; Sang, Nong; Lin, Wei; Shao, Yuanjie

    2018-02-01

    Image location methods are the key technologies of visual navigation, most previous image location methods simply assume the ideal inputs without taking into account the real-world degradations (e.g. low resolution and blur). In view of such degradations, the conventional image location methods first perform image restoration and then match the restored image on the reference image. However, the defective output of the image restoration can affect the result of localization, by dealing with the restoration and location separately. In this paper, we present a joint image restoration and location (JRL) method, which utilizes the sparse representation prior to handle the challenging problem of low-quality image location. The sparse representation prior states that the degraded input image, if correctly restored, will have a good sparse representation in terms of the dictionary constructed from the reference image. By iteratively solving the image restoration in pursuit of the sparest representation, our method can achieve simultaneous restoration and location. Based on such a sparse representation prior, we demonstrate that the image restoration task and the location task can benefit greatly from each other. Extensive experiments on real scene images with Gaussian blur are carried out and our joint model outperforms the conventional methods of treating the two tasks independently.

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

    Science.gov (United States)

    Winter, Thomas C.

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

  1. The Maryland Coastal Plain Aquifer Information System: A GIS-based tool for assessing groundwater resources

    Science.gov (United States)

    Andreasen, David C.; Nardi, Mark R.; Staley, Andrew W.; Achmad, Grufron; Grace, John W.

    2016-01-01

    Groundwater is the source of drinking water for ∼1.4 million people in the Coastal Plain Province of Maryland (USA). In addition, groundwater is essential for commercial, industrial, and agricultural uses. Approximately 0.757 × 109 L d–1 (200 million gallons/d) were withdrawn in 2010. As a result of decades of withdrawals from the coastal plain confined aquifers, groundwater levels have declined by as much as 70 m (230 ft) from estimated prepumping levels. Other issues posing challenges to long-term groundwater sustainability include degraded water quality from both man-made and natural sources, reduced stream base flow, land subsidence, and changing recharge patterns (drought) caused by climate change. In Maryland, groundwater supply is managed primarily by the Maryland Department of the Environment, which seeks to balance reasonable use of the resource with long-term sustainability. The chief goal of groundwater management in Maryland is to ensure safe and adequate supplies for all current and future users through the implementation of appropriate usage, planning, and conservation policies. To assist in that effort, the geographic information system (GIS)–based Maryland Coastal Plain Aquifer Information System was developed as a tool to help water managers access and visualize groundwater data for use in the evaluation of groundwater allocation and use permits. The system, contained within an ESRI ArcMap desktop environment, includes both interpreted and basic data for 16 aquifers and 14 confining units. Data map layers include aquifer and ­confining unit layer surfaces, aquifer extents, borehole information, hydraulic properties, time-series groundwater-level data, well records, and geophysical and lithologic logs. The aquifer and confining unit layer surfaces were generated specifically for the GIS system. The system also contains select groundwater-quality data and map layers that quantify groundwater and surface-water withdrawals. The aquifer

  2. The Paradox of Restoring Native River Landscapes and Restoring Native Ecosystems in the Colorado River System

    Science.gov (United States)

    Schmidt, J. C.

    2014-12-01

    Throughout the Colorado River basin (CRb), scientists and river managers collaborate to improve native ecosystems. Native ecosystems have deteriorated due to construction of dams and diversions that alter natural flow, sediment supply, and temperature regimes, trans-basin diversions that extract large amounts of water from some segments of the channel network, and invasion of non-native animals and plants. These scientist/manager collaborations occur in large, multi-stakeholder, adaptive management programs that include the Lower Colorado River Multi-Species Conservation Program, the Glen Canyon Dam Adaptive Management Program, and the Upper Colorado River Endangered Species Recovery Program. Although a fundamental premise of native species recovery is that restoration of predam flow regimes inevitably leads to native species recovery, such is not the case in many parts of the CRb. For example, populations of the endangered humpback chub (Gila cypha) are largest in the sediment deficit, thermally altered conditions of the Colorado River downstream from Glen Canyon Dam, but these species occur in much smaller numbers in the upper CRb even though the flow regime, sediment supply, and sediment mass balance are less perturbed. Similar contrasts in the physical and biological response of restoration of predam flow regimes occurs in floodplains dominated by nonnative tamarisk (Tamarix spp.) where reestablishment of floods has the potential to exacerbate vertical accretion processes that disconnect the floodplain from the modern flow regime. A significant challenge in restoring segments of the CRb is to describe this paradox of physical and biological response to reestablishment of pre-dam flow regimes, and to clearly identify objectives of environmentally oriented river management. In many cases, understanding the nature of the perturbation to sediment mass balance caused by dams and diversions and understanding the constraints imposed by societal commitments to provide

  3. Generalized hydrogeologic framework and groundwater budget for a groundwater availability study for the glacial aquifer system of the United States

    Science.gov (United States)

    Reeves, Howard W.; Bayless, E. Randall; Dudley, Robert W.; Feinstein, Daniel T.; Fienen, Michael N.; Hoard, Christopher J.; Hodgkins, Glenn A.; Qi, Sharon L.; Roth, Jason L.; Trost, Jared J.

    2017-12-14

    The glacial aquifer system groundwater availability study seeks to quantify (1) the status of groundwater resources in the glacial aquifer system, (2) how these resources have changed over time, and (3) likely system response to future changes in anthropogenic and environmental conditions. The glacial aquifer system extends from Maine to Alaska, although the focus of this report is the part of the system in the conterminous United States east of the Rocky Mountains. The glacial sand and gravel principal aquifer is the largest source of public and self-supplied industrial supply for any principal aquifer and also is an important source for irrigation supply. Despite its importance for water supply, water levels in the glacial aquifer system are generally stable varying with climate and only locally from pumping. The hydrogeologic framework developed for this study includes the information from waterwell records and classification of material types from surficial geologic maps into likely aquifers dominated by sand and gravel deposits. Generalized groundwater budgets across the study area highlight the variation in recharge and discharge primarily driven by climate.

  4. A city scale study on the effects of intensive groundwater heat pump systems on heavy metal contents in groundwater.

    Science.gov (United States)

    García-Gil, Alejandro; Epting, Jannis; Garrido, Eduardo; Vázquez-Suñé, Enric; Lázaro, Jesús Mateo; Sánchez Navarro, José Ángel; Huggenberger, P; Calvo, Miguel Ángel Marazuela

    2016-12-01

    As a result of the increasing use of shallow geothermal resources, hydraulic, thermal and chemical impacts affecting groundwater quality can be observed with ever increasing frequency (Possemiers et al., 2014). To overcome the uncertainty associated with chemical impacts, a city scale study on the effects of intensive geothermal resource use by groundwater heat pump systems on groundwater quality, with special emphasis on heavy metal contents was performed. Statistical analysis of geochemical data obtained from several field campaigns has allowed studying the spatiotemporal relationship between temperature anomalies in the aquifer and trace element composition of groundwater. The relationship between temperature and the concentrations of trace elements resulted in weak correlations, indicating that temperature changes are not the driving factor in enhancing heavy metal contaminations. Regression models established for these correlations showed a very low reactivity or response of heavy metal contents to temperature changes. The change rates of heavy metal contents with respect to temperature changes obtained indicate a low risk of exceeding quality threshold values by means of the exploitation regimes used, neither producing nor enhancing contamination significantly. However, modification of pH, redox potential, electrical conductivity, dissolved oxygen and alkalinity correlated with the concentrations of heavy metals. In this case, the change rates of heavy metal contents are higher, with a greater risk of exceeding threshold values. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Biogeochemical dynamics of pollutants in Insitu groundwater remediation systems

    Science.gov (United States)

    Kumar, N.; Millot, R.; Rose, J.; Négrel, P.; Battaglia-Brunnet, F.; Diels, L.

    2010-12-01

    Insitu (bio) remediation of groundwater contaminants has been area of potential research interest in last few decades as the nature of contaminant encountered has also changed drastically. This gives tough challenge to researchers in finding a common solution for all contaminants together in one plume. Redox processes play significant role in pollutant dynamics and mobility in such systems. Arsenic particularly in reduced environments can get transformed into its reduced form (As3+), which is apparently more mobile and highly toxic. Also parallel sulfate reduction can lead to sulfide production and formation of thioarsenic species. On the other hand heavy metals (Zn, Fe, and Cd) in similar conditions will favour more stable metal sulfide precipitation. In the present work, we tested Zero Valent Iron (ZVI) in handling such issues and found promising results. Although it has been well known for contaminants like arsenic and chlorinated compounds but not much explored for heavy metals. Its high available surface area supports precipitation and co -precipitation of contaminants and its highly oxidizing nature and water born hydrogen production helps in stimulation of microbial activities in sediment and groundwater. These sulfate and Iron reducing bacteria can further fix heavy metals as stable metal sulfides by using hydrogen as potential electron donor. In the present study flow through columns (biotic and control) were set up in laboratory to understand the behaviour of contaminants in subsurface environments, also the impact of microbiology on performance of ZVI was studied. These glass columns (30 x 4cm) with intermediate sampling points were monitored over constant temperature (20°C) and continuous groundwater (up)flow at ~1ml/hr throughout the experiment. Simulated groundwater was prepared in laboratory containing sulfate, metals (Zn,Cd) and arsenic (AsV). While chemical and microbial parameters were followed regularly over time, solid phase has been

  6. A study on the groundwater flow system for deep geological disposal of high level radioactive waste in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chun Soo; Kim, Kyung Su; Bae, Dae Seok; Park, Byoung Yoon; Koh, Young Kown [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-03-01

    The basic framework of groundwater flow is defined as a conceptual 3-D unit of groundwater system based on hydrogeological environments. The fundamental parameters consisting of groundwater system should include topography, geology and climatic conditions. Climatic conditions control the distribution and amounts of groundwater in an interesting study area. The driving forces responsible for groundwater movement are mainly determined by topographic characteristics. The configuration of groundwater system is also controlled by topography. The geological setting and structures control the reservoir size and groundwater flow path. The hydrogeological setting in Korea was classified by primarily topographic characteristics and considered by geological structures and tectonic division. The regional groundwater regime can be grouped into 3 regimes by tectonic setting and four groundwater regions based on an altitude. 35 refs., 9 figs., 21 tabs. (Author)

  7. The Proprioceptive System Regulates Morphologic Restoration of Fractured Bones

    Directory of Open Access Journals (Sweden)

    Ronen Blecher

    2017-08-01

    Full Text Available Successful fracture repair requires restoration of bone morphology and mechanical integrity. Recent evidence shows that fractured bones of neonatal mice undergo spontaneous realignment, dubbed “natural reduction.” Here, we show that natural reduction is regulated by the proprioceptive system and improves with age. Comparison among mice of different ages revealed, surprisingly, that 3-month-old mice exhibited more rapid and effective natural reduction than newborns. Fractured bones of null mutants for transcription factor Runx3, lacking functional proprioceptors, failed to realign properly. Blocking Runx3 expression in the peripheral nervous system, but not in limb mesenchyme, recapitulated the null phenotype, as did inactivation of muscles flanking the fracture site. Egr3 knockout mice, which lack muscle spindles but not Golgi tendon organs, displayed a less severe phenotype, suggesting that both receptor types, as well as muscle contraction, are required for this regulatory mechanism. These findings uncover a physiological role for proprioception in non-autonomous regulation of skeletal integrity.

  8. Groundwater flow system under a rapidly urbanizing coastal city as determined by hydrogeochemistry

    Science.gov (United States)

    Kagabu, Makoto; Shimada, Jun; Delinom, Robert; Tsujimura, Maki; Taniguchi, Makoto

    2011-01-01

    In the Jakarta area (Indonesia), excessive groundwater pumping due to the rapidly increasing population has caused groundwater-related problems such as brackish water contamination in coastal areas and land subsidence. In this study, we adopted multiple hydrogeochemical techniques to demonstrate the groundwater flow system in the Jakarta area. Although almost all groundwater existing in the Jakarta basin is recharged at similar elevations, the water quality and residence time demonstrates a clear difference between the shallow and deep aquifers. Due to the rapid decrease in the groundwater potential in urban areas, we found that the seawater intrusion and the shallow and deep groundwaters are mixing, a conclusion confirmed by major ions, Br -:Cl - ratios, and chlorofluorocarbon (CFC)-12 analysis. Spring water and groundwater samples collected from the southern mountainside area show younger age characteristics with high concentrations of 14C and Ca-HCO 3 type water chemistry. We estimated the residence times of these groundwaters within 45 years under piston flow conditions by tritium analysis. Also, these groundwater ages can be limited to 20-30 years with piston flow evaluated by CFCs. Moreover, due to the magnitude of the CFC-12 concentration, we can use a pseudo age indicator in this field study, because we found a positive correlation between the major type of water chemistry and the CFC-12 concentration.

  9. Evaluation of the proposed pilot groundwater pump and treat demonstration for the Paducah Gaseous Diffusion Plant. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Bodenstein, G.W.; Bonczek, R.R.; Early, T.O.; Hale, T.B.; Huff, D.D.; Nickelson, M.D.; Rightmire, C.T.

    1992-11-01

    This report contains the evaluation and recommendations of a Groundwater Corrective Actions Review Team. The primary goal is to evaluate the technical merit of and the need to implement a proposed groundwater pump-and-treat demonstration project for the Northwest contaminant plume at Paducah, Kentucky. A key distinction recognized by the review team is that the proposed project is intended to be a full-scale hydraulic containment of contaminants migrating from the sources of the plume, not plume remediation. The key questions incorporated into this plan are whether (1) dense, nonaqueous-phase liquids (DNAPLS) are present in the Regional Gravel Aquifer (RGA) at the source of the plume and (2) {sup 99}Tc removal must be included as part of any groundwater treatment process. The first question cannot be answered until the contaminant sources are better defined; the second question requires further risk assessment and/or a policy decision by DOE. Technical evaluation by the review team suggests that the recommended course of action be to modify the proposed work plan to include accurate identification of the sources of contaminants and vertical distribution of contaminants within the Northwest plume before a decision is made on the preferred source-control option. If DNAPLs are not present in the RGA, removal or containment of the sources is recommended. If DNAPLs are present, then hydraulic containment will be required. Finally, the review team recognizes that it is necessary to initiate a more comprehensive analysis of sitewide remediation needs to create links between action taken for the Northwest plume and action taken for other contamination sites at PGPD.

  10. Effects of Sea Level Rise on Groundwater Flow Paths in a Coastal Aquifer System

    Science.gov (United States)

    Morrissey, S. K.; Clark, J. F.; Bennett, M. W.; Richardson, E.; Stute, M.

    2008-05-01

    Changes in groundwater flow in the Floridan aquifer system, South Florida, from the rise in sea level at the end of the last glacial period may be indicative of changes coastal aquifers will experience with continued sea level rise. As sea level rises, the hydraulic head near the coast increases. Coastal aquifers can therefore experience decreased groundwater gradients (increased residence times) and seawater intrusion. Stable isotopes of water, dissolved noble gas temperatures, radiocarbon and He concentrations were analyzed in water collected from 68 wells in the Floridan aquifer system throughout South Florida. Near the recharge area, geochemical data along groundwater flow paths in the Upper Floridan aquifer show a transition from recently recharged groundwater to glacial-aged water. Down gradient from this transition, little variation is apparent in the stable isotopes and noble gas recharge temperatures, indicating that most of the Upper Floridan aquifer contains groundwater recharged during the last glacial period. The rapid 120-meter rise in sea level marking the end of the last glacial period increased the hydraulic head in the Floridan aquifer system near the coast, slowing the flow of groundwater from the recharge area to the ocean and trapping glacial-aged groundwater. The raised sea level also flooded half of the Florida platform and caused seawater to intrude into the Lower Floridan. This circulation of seawater in the Lower Floridan continues today as our data indicate that the groundwater is similar to modern seawater with a freshwater component entering vertically from the recharge area to the Upper Floridan.

  11. Impact of SONET digital cross-connect system architecture on distributed restoration

    International Nuclear Information System (INIS)

    Wu, Tsong-ho; Kobrinski, H.; Lakshman, T.V.

    1994-01-01

    The viability of distributed control restoration using Digital Cross-Connect Systems (DC's) depends on its capability for restoring services within specified time requirements, and its economics for providing restoration compared to other alternatives. In this paper, we report a Bellcore study for the impact of the DCS architecture on distributed restoration. This study concludes that currently proposed distributed control DCS self-healing schemes may not meet the 2-s restoration objective for large metropolitan Local Exchange Carrier's networks, regardless of the distributed algorithm used, if the present DCS system architecture which uses serial message processing and serial path cross-connection remains unchanged. This paper also discusses several DCS architecture enhancement options, including a parallel processing/cross-connect DCS architecture, which may improve the service restoration time. 20 refs

  12. Use of Sodium Dithionite as Part of a More Efficient Groundwater Restoration Method Following In-situ Recovery of Uranium at the Smith-Ranch Highland Site in Wyoming

    Science.gov (United States)

    Harris, R.; Reimus, P. W.; Ware, D.; Williams, K.; Chu, D.; Perkins, G.; Migdissov, A. A.; Bonwell, C.

    2017-12-01

    Uranium is primarily mined for nuclear power production using an aqueous extraction technique called in-situ recovery (ISR). ISR can pollute groundwater with residual uranium and other heavy metals. Reverse osmosis and groundwater sweep are currently used to restore groundwater after ISR mining, but are not permanent solutions. Sodium dithionite is being tested as part of a method to more permanently restore groundwater after ISR mining at the Smith-Ranch Highland site in Wyoming. Sodium dithionite is a chemical reductant that can reduce sediments that were oxidized during ISR. The reduced sediments can reduce soluble uranium (VI) in the groundwater to insoluble uranium (IV). Laboratory studies that use sodium dithionite to treat sediments and waters from the site may help predict how it will behave during a field deployment. An aqueous batch experiment showed that sodium dithionite reduced uranium in post-mined untreated groundwater from 38 ppm to less than 1 ppm after 1 day. A sediment reduction batch experiment showed that sodium dithionite-treated sediments were capable of reducing uranium in post-mined untreated groundwater from 38 ppm to 2 ppm after 7 days. One column experiment is showing post-mined sodium dithionite-treated sediments are capable of reducing uranium in post-mined groundwater for over 30 pore volumes past the initial injection. While these results are promising for field deployments of sodium dithionite, another column experiment with sodium dithionite-treated sediments containing uranium rich organic matter is showing net production of uranium instead of uranium uptake. Sodium dithionite appears to liberate uranium from the organic matter. Another sediment reduction experiment is being conducted to further investigate this hypothesis. These experiments are helping guide plans for field deployments of sodium dithionite at uranium ISR mining sites.

  13. On the restoration of symmetry in paired Fermion systems

    International Nuclear Information System (INIS)

    Flocard, H.

    1997-01-01

    We consider the problem of symmetry restoration as treated by the method of variation after projection (VAP) on good quantum numbers. We show that for compact groups, the convergence of the connected-linked expansion of the VAP kernels over the physically relevant interval of integration of the pairing gauge angle is not guaranteed. We propose instead a method which generates approximations of increasing precision which are periodic with respect to the gauge angle while differing from truncations of the Fourier expansion of the VAP kernels. For the projection on good particle number in paired fermion systems, this new approach is shown to be equivalent to an expansion in powers of the pairing tensor. For the lowest order approximation, an analytical integration over the gauge angle is performed explicitly. It provides the algebraic forms of the single particle Hamiltonian and of the pairing field entering generalized Hartree endash Fock endash Bogoljubov equations. Contrary to most approximations, the validity of the expressions for the energy and mean values of operators thus obtained is not a priori restricted where the fluctuation of the operator associated with the broken symmetry is large. We also derive the first-order correction to the pairing-order parameter. We test the quality of the proposed method on a non-trivial soluble model. copyright 1997 Academic Press, Inc

  14. Groundwater System of Sundarbans (Basanti), West Bengal, India

    DEFF Research Database (Denmark)

    Kopmann, Moritz; Binning, Philip John; Bregnhøj, Henrik

    2018-01-01

    In Basanti, a rural block in the Sundarbans, West Bengal, the water availability is vital for its inhabitants. Groundwater levels are decreasing, and a proper understanding of key factors influencing the water resource is required. In the following, a social review of Basanti is given followed...... by a geologic and hydrostratigraphic analysis. The main hydrologic flows, a water balance, and the trend of salinity in the groundwater are presented. Finally, available long- and short-term drawdown data of South 24 Parganas and Basanti to determine groundwater level and annual recharge trends. The assessment...

  15. Optimized dispatch of wind farms with power control capability for power system restoration

    DEFF Research Database (Denmark)

    Xie, Yunyun; Liu, Changsheng; Wu, Qiuwei

    2017-01-01

    As the power control technology of wind farms develops, the output power of wind farms can be constant, which makes it possible for wind farms to participate in power system restoration. However, due to the uncertainty of wind energy, the actual output power can’t reach a constant dispatch power...... in all time intervals, resulting in uncertain power sags which may induce the frequency of the system being restored to go outside the security limits. Therefore, it is necessary to optimize the dispatch of wind farms participating in power system restoration. Considering that the probability...... distribution function (PDF) of transient power sags is hard to obtain, a robust optimization model is proposed in this paper, which can maximize the output power of wind farms participating in power system restoration. Simulation results demonstrate that the security constraints of the restored system can...

  16. Simulation of the impact of managed aquifer recharge on the groundwater system in Hanoi, Vietnam

    Science.gov (United States)

    Glass, Jana; Via Rico, Daniela A.; Stefan, Catalin; Nga, Tran Thi Viet

    2018-05-01

    A transient numerical groundwater flow model using MODFLOW-NWT was set up and calibrated for Hanoi city, Vietnam, to understand the local groundwater flow system and to suggest solutions for sustainable water resource management. Urban development in Hanoi has caused a severe decline of groundwater levels. The present study evaluates the actual situation and investigates the suitability of managed aquifer recharge (MAR) to stop further depletion of groundwater resources. The results suggest that groundwater is being overexploited, as vast cones of depression exist in parts of the study area. Suitable locations to implement two MAR techniques—riverbank filtration and injection wells—were identified using multi-criteria decision analysis based on geographic information system (GIS). Three predictive scenarios were simulated. The relocation of pumping wells towards the Red River to induce riverbank filtration (first scenario) demonstrates that groundwater levels can be increased, especially in the depression cones. Groundwater levels can also be improved locally by the infiltration of surplus water into the upper aquifer (Holocene) via injection wells during the rainy season (second scenario), but this is not effective to raise the water table in the depression cones. Compared to the first scenario, the combination of riverbank filtration and injection wells (third scenario) shows a slightly raised overall water table. Groundwater flow modeling suggests that local overexploitation can be stopped by a smart relocation of wells from the main depression cones and the expansion of riverbank filtration. This could also avoid further land subsidence while the city's water demand is met.

  17. Applicability and methodology of determining sustainable yield in groundwater systems

    Science.gov (United States)

    Kalf, Frans R. P.; Woolley, Donald R.

    2005-03-01

    There is currently a need for a review of the definition and methodology of determining sustainable yield. The reasons are: (1) current definitions and concepts are ambiguous and non-physically based so cannot be used for quantitative application, (2) there is a need to eliminate varying interpretations and misinterpretations and provide a sound basis for application, (3) the notion that all groundwater systems either are or can be made to be sustainable is invalid, (4) often there are an excessive number of factors bound up in the definition that are not easily quantifiable, (5) there is often confusion between production facility optimal yield and basin sustainable yield, (6) in many semi-arid and arid environments groundwater systems cannot be sensibly developed using a sustained yield policy particularly where ecological constraints are applied. Derivation of sustainable yield using conservation of mass principles leads to expressions for basin sustainable, partial (non-sustainable) mining and total (non-sustainable) mining yields that can be readily determined using numerical modelling methods and selected on the basis of applied constraints. For some cases there has to be recognition that the groundwater resource is not renewable and its use cannot therefore be sustainable. In these cases, its destiny should be the best equitable use. sostenible. Las razones son: (1) los conceptos y definiciones actuales son ambiguos y sin base física de modo que no pueden usarse para aplicación cuantitativa, (2) existe necesidad de eliminar interpretaciones variables y mal interpretaciones y aportar bases sanas para aplicación, (3) la noción de que todos los sistemas de aguas subterráneas son o pueden ser sostenibles no esvalida, (4) frecuentemente existen un numero excesivo de factores ligados a la definición de producción sostenible los cuales no son fácil de cuantificar, (5) frecuentemente existe confusión entre la producción optima de un establecimiento y la

  18. Hydrochemistry of the groundwater flow systems in the Harwell region

    International Nuclear Information System (INIS)

    Alexander, J.

    1984-12-01

    A comprehensive range of geochemical and isotopic parameters were analysed in the groundwater samples taken from the high permeability formations in the Harwell region. These analyses were undertaken as part of a hydro-chemical validation of groundwater circulation patterns derived from potentiometric data. Hydro-chemical investigations were concentrated upon the Corallian and Great Oolite formations since these respectively overlie and underlie the Oxford Clay. (author)

  19. Geochemistry and the understanding of ground-water systems

    Science.gov (United States)

    Glynn, Pierre D.; Plummer, L. Niel

    2005-03-01

    Geochemistry has contributed significantly to the understanding of ground-water systems over the last 50 years. Historic advances include development of the hydrochemical facies concept, application of equilibrium theory, investigation of redox processes, and radiocarbon dating. Other hydrochemical concepts, tools, and techniques have helped elucidate mechanisms of flow and transport in ground-water systems, and have helped unlock an archive of paleoenvironmental information. Hydrochemical and isotopic information can be used to interpret the origin and mode of ground-water recharge, refine estimates of time scales of recharge and ground-water flow, decipher reactive processes, provide paleohydrological information, and calibrate ground-water flow models. Progress needs to be made in obtaining representative samples. Improvements are needed in the interpretation of the information obtained, and in the construction and interpretation of numerical models utilizing hydrochemical data. The best approach will ensure an optimized iterative process between field data collection and analysis, interpretation, and the application of forward, inverse, and statistical modeling tools. Advances are anticipated from microbiological investigations, the characterization of natural organics, isotopic fingerprinting, applications of dissolved gas measurements, and the fields of reaction kinetics and coupled processes. A thermodynamic perspective is offered that could facilitate the comparison and understanding of the multiple physical, chemical, and biological processes affecting ground-water systems. La géochimie a contribué de façon importante à la compréhension des systèmes d'eaux souterraines pendant les 50 dernières années. Les avancées ont portées sur le développement du concept des faciès hydrochimiques, sur l'application de la théorie des équilibres, l'étude des processus d'oxydoréduction, et sur la datation au radiocarbone. D'autres concepts, outils et

  20. Mitigation of voltage sags in the distribution system with dynamic voltage restorer

    International Nuclear Information System (INIS)

    Viglas, D.; Belan, A.

    2012-01-01

    Dynamic voltage restorer is a custom power device that is used to improve voltage sags or swells in electrical distribution system. The components of the Dynamic Voltage Restorer consist of injection transformers, voltage source inverter, passive filters and energy storage. The main function of the Dynamic voltage restorer is used to inject three phase voltage in series and in synchronism with the grid voltages in order to compensate voltage disturbances. This article deals with mitigation of voltage sags caused by three-phase short circuit. Dynamic voltage restorer is modelled in MATLAB/Simulink. (Authors)

  1. Modernizing Distribution System Restoration to Achieve Grid Resiliency Against Extreme Weather Events: An Integrated Solution

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chen; Wang, Jianhui; Ton, Dan

    2017-07-07

    Recent severe power outages caused by extreme weather hazards have highlighted the importance and urgency of improving the resilience of the electric power grid. As the distribution grids still remain vulnerable to natural disasters, the power industry has focused on methods of restoring distribution systems after disasters in an effective and quick manner. The current distribution system restoration practice for utilities is mainly based on predetermined priorities and tends to be inefficient and suboptimal, and the lack of situational awareness after the hazard significantly delays the restoration process. As a result, customers may experience an extended blackout, which causes large economic loss. On the other hand, the emerging advanced devices and technologies enabled through grid modernization efforts have the potential to improve the distribution system restoration strategy. However, utilizing these resources to aid the utilities in better distribution system restoration decision-making in response to extreme weather events is a challenging task. Therefore, this paper proposes an integrated solution: a distribution system restoration decision support tool designed by leveraging resources developed for grid modernization. We first review the current distribution restoration practice and discuss why it is inadequate in response to extreme weather events. Then we describe how the grid modernization efforts could benefit distribution system restoration, and we propose an integrated solution in the form of a decision support tool to achieve the goal. The advantages of the solution include improving situational awareness of the system damage status and facilitating survivability for customers. The paper provides a comprehensive review of how the existing methodologies in the literature could be leveraged to achieve the key advantages. The benefits of the developed system restoration decision support tool include the optimal and efficient allocation of repair crews

  2. Application of science-based restoration planning to a desert river system

    Science.gov (United States)

    Laub, Brian G.; Jimenez, Justin; Budy, Phaedra

    2015-01-01

    Persistence of many desert river species is threatened by a suite of impacts linked to water infrastructure projects that provide human water security where water is scarce. Many desert rivers have undergone regime shifts from spatially and temporally dynamic ecosystems to more stable systems dominated by homogenous physical habitat. Restoration of desert river systems could aid in biodiversity conservation, but poses formidable challenges due to multiple threats and the infeasibility of recovery to pre-development conditions. The challenges faced in restoring desert rivers can be addressed by incorporating scientific recommendations into restoration planning efforts at multiple stages, as demonstrated here through an example restoration project. In particular, use of a watershed-scale planning process can identify data gaps and irreversible constraints, which aid in developing achievable restoration goals and objectives. Site-prioritization focuses limited the resources for restoration on areas with the greatest potential to improve populations of target organisms. Investment in research to understand causes of degradation, coupled with adoption of a guiding vision is critical for identifying feasible restoration actions that can enhance river processes. Setting monitoring as a project goal, developing hypotheses for expected outcomes, and implementing restoration as an experimental design will facilitate adaptive management and learning from project implementation. Involvement of scientists and managers during all planning stages is critical for developing process-based restoration actions and an implementation plan to maximize learning. The planning process developed here provides a roadmap for use of scientific recommendations in future efforts to recover dynamic processes in imperiled riverine ecosystems.

  3. Application of Science-Based Restoration Planning to a Desert River System

    Science.gov (United States)

    Laub, Brian G.; Jimenez, Justin; Budy, Phaedra

    2015-06-01

    Persistence of many desert river species is threatened by a suite of impacts linked to water infrastructure projects that provide human water security where water is scarce. Many desert rivers have undergone regime shifts from spatially and temporally dynamic ecosystems to more stable systems dominated by homogenous physical habitat. Restoration of desert river systems could aid in biodiversity conservation, but poses formidable challenges due to multiple threats and the infeasibility of recovery to pre-development conditions. The challenges faced in restoring desert rivers can be addressed by incorporating scientific recommendations into restoration planning efforts at multiple stages, as demonstrated here through an example restoration project. In particular, use of a watershed-scale planning process can identify data gaps and irreversible constraints, which aid in developing achievable restoration goals and objectives. Site-prioritization focuses limited the resources for restoration on areas with the greatest potential to improve populations of target organisms. Investment in research to understand causes of degradation, coupled with adoption of a guiding vision is critical for identifying feasible restoration actions that can enhance river processes. Setting monitoring as a project goal, developing hypotheses for expected outcomes, and implementing restoration as an experimental design will facilitate adaptive management and learning from project implementation. Involvement of scientists and managers during all planning stages is critical for developing process-based restoration actions and an implementation plan to maximize learning. The planning process developed here provides a roadmap for use of scientific recommendations in future efforts to recover dynamic processes in imperiled riverine ecosystems.

  4. In-situ remediation system for groundwater and soils

    Science.gov (United States)

    Corey, John C.; Kaback, Dawn S.; Looney, Brian B.

    1993-01-01

    A method and system for in-situ remediation of contaminated groundwater and soil where the contaminants, such as toxic metals, are carried in a subsurface plume. The method comprises selection and injection into the soil of a fluid that will cause the contaminants to form stable, non-toxic compounds either directly by combining with the contaminants or indirectly by creating conditions in the soil or changing the conditions of the soil so that the formation of stable, non-toxic compounds between the contaminants and existing substances in the soil are more favorable. In the case of non-toxic metal contaminants, sulfides or sulfates are injected so that metal sulfides or sulfates are formed. Alternatively, an inert gas may be injected to stimulate microorganisms in the soil to produce sulfides which, in turn, react with the metal contaminants. Preferably, two wells are used, one to inject the fluid and one to extract the unused portion of the fluid. The two wells work in combination to create a flow of the fluid across the plume to achieve better, more rapid mixing of the fluid and the contaminants.

  5. Isotopic study of the effect of Tarbela reservoir on the groundwater system in the downstream areas

    International Nuclear Information System (INIS)

    Sajjad, M.I.; Tasneem, M.A.; Hussain, S.D.; Khan, I.H.; Ali, M.; Latif, Z.

    1994-04-01

    Isotopic studies were carried out on the right side of river Indus, downstream of Tarbela dam to study the effect of Tarbela Reservoir on the groundwater system. The main objectives of the study were to determine the hydraulic connection, if any, between the Tarbela Lake and the groundwater appearing in the ponds near Gadon Amazai, see the effect of Tarbela dam on the groundwater system in the downstream areas, compute the relative contribution of different recharge sources towards groundwater system and to estimate residence time of groundwater in the area. Isotopic data reveals that the ponds near Gadoon Amazai area are being recharged by local rains and there is no contribution of Tarbela lake. The area around Gadoon Amazai, Topi and Kalabat is solely recharged by local rains while the area around Swabi, Zaida and Lahor has mixed recharge with major contribution from local canal system. Tritium data suggests that the residence time of groundwater in the study area varies from a few years to 30 years. Te groundwater in the area has low dissolved salt contents and is, generally, of good quality. (author) 19 figs

  6. Benefits of using a Social-Ecological Systems Approach to Conceptualize and Model Wetlands Restoration

    Science.gov (United States)

    Using a social-ecological systems (SES) perspective to examine wetland restoration helps decision-makers recognize interdependencies and relations between ecological and social components of coupled systems. Conceptual models are an invaluable tool to capture, visualize, and orga...

  7. Pump Hydro Energy Storage systems (PHES) in groundwater flooded quarries

    Science.gov (United States)

    Poulain, Angélique; de Dreuzy, Jean-Raynald; Goderniaux, Pascal

    2018-04-01

    Pump storage hydroelectricity is an efficient way to temporarily store energy. This technique requires to store temporarily a large volume of water in an upper reservoir, and to release it through turbines to the lower reservoir, to produce electricity. Recently, the idea of using old flooded quarries as a lower reservoir has been evoked. However, these flooded quarries are generally connected to unconfined aquifers. Consequently, pumping or injecting large volumes of water, within short time intervals, will have an impact on the adjacent aquifers. Conversely, water exchanges between the quarry and the aquifer may also influence the water level fluctuations in the lower reservoir. Using numerical modelling, this study investigates the interactions between generic flooded open pit quarries and adjacent unconfined aquifers, during various pump-storage cyclic stresses. The propagation of sinusoidal stresses in the adjacent porous media and the amplitude of water level fluctuations in the quarry are studied. Homogeneous rock media and the presence of fractures in the vicinity of the quarry are considered. Results show that hydrological quarry - rock interactions must be considered with caution, when implementing pump - storage systems. For rock media characterized by high hydraulic conductivity and porosity values, water volumes exchanges during cycles may affect significantly the amplitude of the water level fluctuations in the quarry, and as a consequence, the instantaneous electricity production. Regarding the impact of the pump - storage cyclic stresses on the surrounding environment, the distance of influence is potentially high under specific conditions, and is enhanced with the occurrence of rock heterogeneities, such as fractures. The impact around the quarry used as a lower reservoir thus appears as an important constraining factor regarding the feasibility of pump - storage systems, to be assessed carefully if groundwater level fluctuations around the quarry

  8. A Dynamic Programming based method for optimizing power system restoration with high wind power penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Li, Pengfei

    2016-01-01

    and relatively low cost. Thus, many countries are increasing the wind power penetration in their power system step by step, such as Denmark, Spain and Germany. The incremental wind power penetration brings a lot of new issues in operation and programming. The power system sometimes will operate close to its...... stable limits. Once the blackout happens, a well-designed restoration strategy is significant. This paper focuses on how to ameliorate the power system restoration procedures to adapt the high wind power penetration and how to take full advantages of the wind power plants during the restoration....... In this paper, the possibility to exploit the stochastic wind power during restoration was discussed, and a Dynamic Programming (DP) method was proposed to make wind power contribute in the restoration rationally as far as possible. In this paper, the method is tested and verified by a modified IEEE 30 Buses...

  9. Frequency Monitoring and Control during Power System Restoration Based on Wide Area Measurement System

    Directory of Open Access Journals (Sweden)

    Saber Nourizadeh

    2011-01-01

    Full Text Available Frequency control during power system restoration has not been strongly addressed. Operators are often concerned with the offline sizing of load and generation steps, but, nowadays, the introduction of Wide Area Measurement System (WAMS makes it possible to monitor the stability of power system online. The constraints of WAMS operation result in some changes in power system frequency control. This paper proposes a novel methodology for frequency control and monitoring during the early steps of power system restoration based on WAMS. Detailed load modeling is achieved based on the static load modeling approach. Power generators' modeling is also accomplished utilizing the single machine equivalent of the power system based on PMU measurements. Simulation results of the presented methodology on the 39 bus New England power system clearly show the effectiveness and applicability of the proposed method. The simulation results show that the presented approach has a completely acceptable precision and an outstanding speed with less than 0.05% error. The outstanding speed of the presented approach along with the result precision will result in a great promotion in power system restoration methodologies.

  10. Application of MODFLOW and geographic information system to groundwater flow simulation in North China Plain, China

    Science.gov (United States)

    Wang, Shiqin; Shao, Jingli; Song, Xianfang; Zhang, Yongbo; Huo, Zhibin; Zhou, Xiaoyuan

    2008-10-01

    MODFLOW is a groundwater modeling program. It can be compiled and remedied according to the practical applications. Because of its structure and fixed data format, MODFLOW can be integrated with Geographic Information Systems (GIS) technology for water resource management. The North China Plain (NCP), which is the politic, economic and cultural center of China, is facing with water resources shortage and water pollution. Groundwater is the main water resource for industrial, agricultural and domestic usage. It is necessary to evaluate the groundwater resources of the NCP as an entire aquifer system. With the development of computer and internet information technology it is also necessary to integrate the groundwater model with the GIS technology. Because the geological and hydrogeological data in the NCP was mainly in MAPGIS format, the powerful function of GIS of disposing of and analyzing spatial data and computer languages such as Visual C and Visual Basic were used to define the relationship between the original data and model data. After analyzing the geological and hydrogeological conditions of the NCP, the groundwater flow numerical simulation modeling was constructed with MODFLOW. On the basis of GIS, a dynamic evaluation system for groundwater resources under the internet circumstance was completed. During the process of constructing the groundwater model, a water budget was analyzed, which showed a negative budget in the NCP. The simulation period was from 1 January 2002 to 31 December 2003. During this period, the total recharge of the groundwater system was 49,374 × 106 m3 and the total discharge was 56,530 × 106 m3 the budget deficit was -7,156 × 106 m3. In this integrated system, the original data including graphs and attribution data could be stored in the database. When the process of evaluating and predicting groundwater flow was started, these data were transformed into files that the core program of MODFLOW could read. The calculated water

  11. Iodine mobilization in groundwater system at Datong basin, China: Evidence from hydrochemistry and fluorescence characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junxia; Wang, Yanxin, E-mail: yx.wang@cug.edu.cn; Guo, Wei; Xie, Xianjun; Zhang, Liping; Liu, Yaqing; Kong, Shuqiong

    2014-01-01

    Characterizing the speciation of iodine in groundwater is essential for understanding its hydrogeochemical behavior in aquifer systems. To quantify the variations in iodine speciation and assess factors controlling the distribution and transformation of iodine, 82 groundwater samples and 1 rain water were collected from the Datong basin, northern China in this study. Factor analysis (FA) and excitation emission matrix with parallel factor analysis (EEM–PARAFAC) were used to clarify the potential relationships among iodine species and other hydrochemical parameters. The iodine concentrations of groundwater range from 6.23 to 1380 μg L{sup −1} with 47% of samples exceeding its drinking water level of 150 μg L{sup −1} as recommended by the Chinese government. 57% of samples have ratios of iodate to total iodine greater than 60%, while iodide as the major species in 22% of the samples. Significant amounts of organic iodine with concentrations higher than 100 μg L{sup −1} were observed in 9 groundwater samples. Redox conditions of groundwater system strongly affect iodine concentration and speciation of inorganic iodine in groundwater, and extremely reducing condition restricts the iodine release from sediments into groundwater. The results of FA show that iodine mobilization in groundwater is related to the nature of dissolved organic matter. EEM-PARAFAC model demonstrates the dominance of terrestrial DOM sources and the presence of microbial activities in groundwater system of the Datong basin. It is proposed that degradation of organic matter and reductive dissolution of iron oxyhydroxides are major hydrogeochemical processes responsible for the mobilization of iodine release and the genesis of organic iodine. - Highlights: • Iodine species in groundwater was studied from Datong basin, northern China. • Weakly alkaline environment favors the accumulation of iodine in groundwater. • Iodate is the major species of iodine in groundwater from Datong

  12. Examining the impacts of increased corn production on groundwater quality using a coupled modeling system

    Science.gov (United States)

    This study demonstrates the value of a coupled chemical transport modeling system for investigating groundwater nitrate contamination responses associated with nitrogen (N) fertilizer application and increased corn production. The coupled Community Multiscale Air Quality Bidirect...

  13. Identification of manganese as a toxicant in a groundwater treatment system: Addressing naturally occurring toxicants

    International Nuclear Information System (INIS)

    Goodfellow, W. Jr.; Sohn, V.; Richey, M.; Yost, J.

    1995-01-01

    Effluent from a groundwater remediation system at a bulk oil storage and distribution terminal has been chronically toxic to Ceriodaphnia dubia. The remediation system was designed in response to a hydrocarbon plume in the area of the terminal. The remediation system consists of a series of groundwater recovery wells and groundwater intercept trench systems with groundwater treatment and phased-separated hydrocarbon recovery systems. The groundwater treatment and petroleum recovery systems consist of oil/water separators, product recovery tanks, air strippers, filters, and carbon adsorption units. The characteristics of this effluent are low total suspended solids, total dissolved solids, and hardness concentrations as well as meeting stringent NPDES permit requirements for lead, copper, zinc, mercury, total petroleum hydrocarbons, and BTEX. Additional priority pollutant evaluations revealed no compounds of concern. Performance of a Toxicity identification Evaluation (TIE) indicated that manganese was the principle toxicant in the effluent. Manganese is a naturally occurring constituent in this groundwater source and is not added to the treatment system. This paper will present the results of the TIE with a discussion of treatability/control options for manganese control at this facility. Recommendations for addressing naturally occurring toxicants that are not a result of the facility's operations will also be presented

  14. Simulation of the Groundwater-Flow System in Pierce, Polk, and St. Croix Counties, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.

    2009-01-01

    Groundwater is the sole source of residential water supply in Pierce, Polk, and St. Croix Counties, Wisconsin. A regional three-dimensional groundwater-flow model and three associated demonstration inset models were developed to simulate the groundwater-flow systems in the three-county area. The models were developed by the U.S. Geological Survey in cooperation with the three county governments. The objectives of the regional model of Pierce, Polk, and St. Croix Counties were to improve understanding of the groundwaterflow system and to develop a tool suitable for evaluating the effects of potential water-management programs. The regional groundwater-flow model described in this report simulates the major hydrogeologic features of the modeled area, including bedrock and surficial aquifers, groundwater/surface-water interactions, and groundwater withdrawals from high-capacity wells. Results from the regional model indicate that about 82 percent of groundwater in the three counties is from recharge within the counties; 15 percent is from surface-water sources, consisting primarily of recirculated groundwater seepage in areas with abrupt surface-water-level changes, such as near waterfalls, dams, and the downgradient side of reservoirs and lakes; and 4 percent is from inflow across the county boundaries. Groundwater flow out of the counties is to streams (85 percent), outflow across county boundaries (14 percent), and pumping wells (1 percent). These results demonstrate that the primary source of groundwater withdrawn by pumping wells is water that recharges within the counties and would otherwise discharge to local streams and lakes. Under current conditions, the St. Croix and Mississippi Rivers are groundwater discharge locations (gaining reaches) and appear to function as 'fully penetrating' hydraulic boundaries such that groundwater does not cross between Wisconsin and Minnesota beneath them. Being hydraulic boundaries, however, they can change in response to

  15. Residence times of groundwater and nitrate transport in coastal aquifer systems: Daweijia area, northeastern China.

    Science.gov (United States)

    Han, Dongmei; Cao, Guoliang; McCallum, James; Song, Xianfang

    2015-12-15

    Groundwater within the coastal aquifer systems of the Daweijia area in northeastern China is characterized by a large of variations (33-521mg/L) in NO3(-) concentrations. Elevated nitrate concentrations, in addition to seawater intrusion in the Daweijia well field, both attributable to anthropogenic activities, may impact future water-management practices. Chemical and stable isotopic (δ(18)O, δ(2)H) analysis, (3)H and CFCs methods were applied to provide a better understanding of the relationship between the distribution of groundwater mean residence time (MRT) and nitrate transport, and to identify sources of nitrate concentrations in the complex coastal aquifer systems. There is a relatively narrow range of isotopic composition (ranging from -8.5 to -7.0‰) in most groundwater. Generally higher tritium contents observed in the wet season relative to the dry season may result from rapid groundwater circulation in response to the rainfall through the preferential flow paths. In the well field, the relatively increased nitrate concentrations of groundwater, accompanied by the higher tritium contents in the wet season, indicate the nitrate pollution can be attributed to domestic wastes. The binary exponential and piston-flow mixing model (BEP) yielded feasible age distributions based on the conceptual model. The good inverse relationship between groundwater MRTs (92-467years) and the NO3(-) concentrations in the shallow Quaternary aquifers indicates that elevated nitrate concentrations are attributable to more recent recharge for shallow groundwater. However, there is no significant relationship between the MRTs (8-411years) and the NO3(-) concentrations existing in the carbonate aquifer system, due to the complex hydrogeological conditions, groundwater age distributions and the range of contaminant source areas. Nitrate in the groundwater system without denitrification effects could accumulate and be transported for tens of years, through the complex carbonate

  16. Implementing the Prepaid Smart Meter System for Irrigated Groundwater Production in Northern China: Status and Problems

    OpenAIRE

    Xiaowei Wang; Jingli Shao; Frank van Steenbergen; Qiulan Zhang

    2017-01-01

    To reduce the gap between groundwater demand and supply caused by agricultural groundwater over-exploitation, the Prepaid Smart Meter System (PSMS) is being strongly implemented by the Chinese government in northern China. This study reports the analysis and results of PSMS field surveys in six typical provinces in northern China as well as domestic literature reviews. Based on the architecture and implementation policies of the system, the implementation differences between areas and the inf...

  17. Determination of timescales of nitrate contamination by groundwater age models in a complex aquifer system

    Science.gov (United States)

    Koh, E. H.; Lee, E.; Kaown, D.; Lee, K. K.; Green, C. T.

    2017-12-01

    Timing and magnitudes of nitrate contamination are determined by various factors like contaminant loading, recharge characteristics and geologic system. Information of an elapsed time since recharged water traveling to a certain outlet location, which is defined as groundwater age, can provide indirect interpretation related to the hydrologic characteristics of the aquifer system. There are three major methods (apparent ages, lumped parameter model, and numerical model) to date groundwater ages, which differently characterize groundwater mixing resulted by various groundwater flow pathways in a heterogeneous aquifer system. Therefore, in this study, we compared the three age models in a complex aquifer system by using observed age tracer data and reconstructed history of nitrate contamination by long-term source loading. The 3H-3He and CFC-12 apparent ages, which did not consider the groundwater mixing, estimated the most delayed response time and a highest period of the nitrate loading had not reached yet. However, the lumped parameter model could generate more recent loading response than the apparent ages and the peak loading period influenced the water quality. The numerical model could delineate various groundwater mixing components and its different impacts on nitrate dynamics in the complex aquifer system. The different age estimation methods lead to variations in the estimated contaminant loading history, in which the discrepancy in the age estimation was dominantly observed in the complex aquifer system.

  18. A GIS-Enabled, Michigan-Specific, Hierarchical Groundwater Modeling and Visualization System

    Science.gov (United States)

    Liu, Q.; Li, S.; Mandle, R.; Simard, A.; Fisher, B.; Brown, E.; Ross, S.

    2005-12-01

    Efficient management of groundwater resources relies on a comprehensive database that represents the characteristics of the natural groundwater system as well as analysis and modeling tools to describe the impacts of decision alternatives. Many agencies in Michigan have spent several years compiling expensive and comprehensive surface water and groundwater inventories and other related spatial data that describe their respective areas of responsibility. However, most often this wealth of descriptive data has only been utilized for basic mapping purposes. The benefits from analyzing these data, using GIS analysis functions or externally developed analysis models or programs, has yet to be systematically realized. In this talk, we present a comprehensive software environment that allows Michigan groundwater resources managers and frontline professionals to make more effective use of the available data and improve their ability to manage and protect groundwater resources, address potential conflicts, design cleanup schemes, and prioritize investigation activities. In particular, we take advantage of the Interactive Ground Water (IGW) modeling system and convert it to a customized software environment specifically for analyzing, modeling, and visualizing the Michigan statewide groundwater database. The resulting Michigan IGW modeling system (IGW-M) is completely window-based, fully interactive, and seamlessly integrated with a GIS mapping engine. The system operates in real-time (on the fly) providing dynamic, hierarchical mapping, modeling, spatial analysis, and visualization. Specifically, IGW-M allows water resources and environmental professionals in Michigan to: * Access and utilize the extensive data from the statewide groundwater database, interactively manipulate GIS objects, and display and query the associated data and attributes; * Analyze and model the statewide groundwater database, interactively convert GIS objects into numerical model features

  19. APPLICATION OF 3D DIGITAL SCANNING AND CAD/CAM SYSTEMS FOR ZIRCONIA INDIRECT RESTORATIONS

    Directory of Open Access Journals (Sweden)

    Mariela Tsanova

    2016-09-01

    Full Text Available Object: To study the CAD/CAM systems’ possibilities for manufacturing Zirconia indirect restorations for restoring vital, vastly devastated teeth. Material and methods: Five patients with vital, heavily destroyed molars were included in the clinical study. The teeth were prepared according to requirements for Zirconia restorations. The impressions were taken with 3D intraoral scanner. The acquired data is transmitted electronically for designing the future restoration by the CAD software. After designing, the restoration is milled by the CAM module and sintered, according to a specially projected programme in accordance with the manufacturing demands. After clinical check-up, the restorations are glazed, air-blasted and cemented. Results: Setting up an individual protocol for working with CAD/CAM systems for restoring vital, severely devastated teeth with Zirconia indirect restorations. A research is made on 3D digital scanning, occlusal and proximal modeling, virtual articulation, analyzing the incline of the cavity walls, the thickness of the restoration and the possibilities for restoring the anatomy of the tooth according to patient’s individual characteristics of the teeth’s arch. Conclusion: The scanning and design process should be evaluated with the same quality control as when using traditional methods. The CAD software requires excellent preparation of the tooth cavity and digital scanning. This is the reason why these systems require a thorough understanding of CAD/CAM calibration and parameters of the product to be clinically acceptable. Once understood, CAD/CAM dentistry can create detailed and accurate restorations that function and perform with great success and longevity.

  20. Isotopes reveal dynamics of groundwater system in Region 2, Philippines

    International Nuclear Information System (INIS)

    Mendoza, N.D.S.; Racadio, C.D.T.; Sucgang, R.J.; Castañeda, S.S.

    2015-01-01

    Steady economic and population growth in Region 2 could lead to an exponential increase freshwater demand. However, region 2’s main source of freshwater is groundwater and, if not checked and managed carefully, it could eventually affect the availability and sustainability of groundwater resources in Water Resource Region 2 (WRR2). Stable isotopes along with Tritium analysis in different water bodies such as rain, shallow and deep groundwater, springs and rivers were used to gain insight about the hydrological process in WRR2. Local meteoric water line for WRR2 was found to be δ2H = 8.6 δ 18O + 13.3 (r = 0.98). The estimated annual mean, which was used as a local index was to be -7.1 ‰ δ “1”8O_v_s_m_o_w_-_s_l_a_p. Shallow wells (20 – 30 m) and production wells (multi-screened wells, max depth of about 100 – 120m) were found to exhibit relatively more enrich than the index (i.e. -7.1‰) with means of -6.2 ‰ (s.d. 1.1‰, n=19) and -6.6 ‰ (s.d. 0.9; n= 151), respectively, which was an indication of infiltration of evaporated waters possibly from river and irrigation waters. Tritium analysis were done on selected sites to identify groundwater age (GWA) and possibly track the flow of groundwater from recharge areas (such as in Nueva Vizcaya, GWA = 3 years) down to the plains (Tuguegarao, GWA range from 9 to 30 years). Groundwaters drawn from production wells in Tuguegarao with ages of more than 30 years suggest that more fraction of water were being drawn from deeper aquifers. Such scenario could mean that were less water in shallow aquifers (e.g. 30 m deep) which are typically younger in age than waters found at deeper aquifers (e.g. 100 m deep). (author)

  1. Investigations of groundwater system and simulation of regional groundwater flow for North Penn Area 7 Superfund site, Montgomery County, Pennsylvania

    Science.gov (United States)

    Senior, Lisa A.; Goode, Daniel J.

    2013-01-01

    by USGS at the site and results from other studies support, and are consistent with, a conceptual model of a layered leaky aquifer where the dip of the beds has a strong control on hydraulic connections in the groundwater system. Connections within and (or) parallel to bedding tend to be greater than across bedding. Transmissivities of aquifer intervals isolated by packers ranged over three orders of magnitude [from about 2.8 to 2,290 square feet per day (ft2/d) or 0.26 to 213 square meters per day (m2/d)], did not appear to differ much by mapped geologic unit, but showed some relation to depth being relatively smaller in the shallowest and deepest intervals (0 to 50 ft and more than 250 ft below land surface, respectively) compared to the intermediate depth intervals (50 to 250 ft below land surface) tested. Transmissivities estimated from multiple-observation well aquifer tests ranged from about 700 to 2,300 ft2/d (65 to 214 m2/d). Results of chemical analyses of water from isolated intervals or monitoring wells open to short sections of the aquifer show vertical differences in concentrations; chloride and silica concentrations generally were greater in shallow intervals than in deeper intervals. Chloride concentrations greater than 100 milligrams per liter (mg/L), combined with distinctive chloride/bromide ratios, indicate a different source of chloride in the western part of North Penn Area 7 than elsewhere in the site. Groundwater flow at a regional scale under steady-state conditions was simulated by use of a numerical model (MODFLOW-2000) for North Penn Area 7 with different layers representing saprolite/highly weathered rock near the surface and unweathered competent bedrock. The sedimentary formations that underlie the study area were modeled using dipping model layers for intermediate and deep zones of unweathered, fractured rock. Horizontal cell model size was 100 meters (m) by 100 meters (328 ft by 328 ft), and model layer thickness ranged from 6 m (19

  2. Complex groundwater flow systems as traveling agent models

    Directory of Open Access Journals (Sweden)

    Oliver López Corona

    2014-10-01

    Full Text Available Analyzing field data from pumping tests, we show that as with many other natural phenomena, groundwater flow exhibits complex dynamics described by 1/f power spectrum. This result is theoretically studied within an agent perspective. Using a traveling agent model, we prove that this statistical behavior emerges when the medium is complex. Some heuristic reasoning is provided to justify both spatial and dynamic complexity, as the result of the superposition of an infinite number of stochastic processes. Even more, we show that this implies that non-Kolmogorovian probability is needed for its study, and provide a set of new partial differential equations for groundwater flow.

  3. Groundwater flow and mixing in a wetland–stream system

    DEFF Research Database (Denmark)

    Karan, Sachin; Engesgaard, Peter Knudegaard; Zibar, Majken Caroline Looms

    2013-01-01

    steady-state groundwater model that was calibrated against average head observations. The model results were tested against groundwater fluxes determined from streambed temperature measurements. Discharge varied up to one order of magnitude across the stream and the model was successful in capturing...... in the top of the aquifer and immediately underneath the streambed no NO3- was detected deeper within the aquifer. An inverse relationship between NO3- and SO42- suggests that pyrite oxidation takes place in the deeper parts of the aquifer. Simulated flow path lines showed very different origins for deeper...

  4. Septic Systems Contribution to Phosphorus in Shallow Groundwater: Field-Scale Studies Using Conventional Drainfield Designs

    Science.gov (United States)

    Mechtensimer, Sara

    2017-01-01

    Septic systems can be a potential source of phosphorus (P) in groundwater and contribute to eutrophication in aquatic systems. Our objective was to investigate P transport from two conventional septic systems (drip dispersal and gravel trench) to shallow groundwater. Two new in-situ drainfields (6.1 m long by 0.61 m wide) with a 3.72 m2 infiltrative surface were constructed. The drip dispersal drainfield was constructed by placing 30.5 cm commercial sand on top of natural soil and the gravel trench drainfield was constructed by placing 30.5 cm of gravel on top of 30.5 cm commercial sand and natural soil. Suction cup lysimeters were installed in the drainfields (at 30.5, 61, 106.7 cm below infiltrative surface) and piezometers were installed in the groundwater (>300 cm below infiltrative surface) to capture P dynamics from the continuum of unsaturated to saturated zones in the septic systems. Septic tank effluent (STE), soil-water, and groundwater samples were collected for 64 events (May 2012–Dec 2013) at 2 to 3 days (n = 13), weekly (n = 29), biweekly (n = 17), and monthly (n = 5) intervals. One piezometer was installed up-gradient of the drainfields to monitor background groundwater (n = 15). Samples were analyzed for total P (TP), orthophosphate-P (PO4–P), and other–P (TP—PO4-P). The gravel trench drainfield removed significantly (p300 cm in the groundwater, both systems had similar TP reductions of >97%. After 18 months of STE application, there was no significant increase in groundwater TP concentrations in both systems. We conclude that both drainfield designs are effective at reducing P transport to shallow groundwater. PMID:28107505

  5. Septic Systems Contribution to Phosphorus in Shallow Groundwater: Field-Scale Studies Using Conventional Drainfield Designs.

    Directory of Open Access Journals (Sweden)

    Sara Mechtensimer

    Full Text Available Septic systems can be a potential source of phosphorus (P in groundwater and contribute to eutrophication in aquatic systems. Our objective was to investigate P transport from two conventional septic systems (drip dispersal and gravel trench to shallow groundwater. Two new in-situ drainfields (6.1 m long by 0.61 m wide with a 3.72 m2 infiltrative surface were constructed. The drip dispersal drainfield was constructed by placing 30.5 cm commercial sand on top of natural soil and the gravel trench drainfield was constructed by placing 30.5 cm of gravel on top of 30.5 cm commercial sand and natural soil. Suction cup lysimeters were installed in the drainfields (at 30.5, 61, 106.7 cm below infiltrative surface and piezometers were installed in the groundwater (>300 cm below infiltrative surface to capture P dynamics from the continuum of unsaturated to saturated zones in the septic systems. Septic tank effluent (STE, soil-water, and groundwater samples were collected for 64 events (May 2012-Dec 2013 at 2 to 3 days (n = 13, weekly (n = 29, biweekly (n = 17, and monthly (n = 5 intervals. One piezometer was installed up-gradient of the drainfields to monitor background groundwater (n = 15. Samples were analyzed for total P (TP, orthophosphate-P (PO4-P, and other-P (TP-PO4-P. The gravel trench drainfield removed significantly (p300 cm in the groundwater, both systems had similar TP reductions of >97%. After 18 months of STE application, there was no significant increase in groundwater TP concentrations in both systems. We conclude that both drainfield designs are effective at reducing P transport to shallow groundwater.

  6. Clinical performance of a glass ionomer restorative system: a 6-year evaluation.

    Science.gov (United States)

    Gurgan, Sevil; Kutuk, Zeynep Bilge; Ergin, Esra; Oztas, Sema Seval; Cakir, Filiz Yalcin

    2017-09-01

    The aim of this study is to evaluate the long-term clinical performance of a glass ionomer (GI) restorative system in the restoration of posterior teeth compared with a micro-filled hybrid posterior composite. A total of 140 (80 Cl1 and 60 Cl2) lesions in 59 patients were restored with a GI system (Equia) or a micro hybrid composite (Gradia Direct). Restorations were evaluated at baseline and yearly during 6 years according to the modified-USPHS criteria. Negative replicas at each recall were observed under SEM to evaluate surface characteristics. Data were analyzed with Cohcran's Q and McNemar's tests (p evaluated in 47 patients with a recall rate of 79.6% at 6 years. Significant differences were found in marginal adaptation and marginal discoloration for both restorative materials for Cl1 and Cl2 restorations (p  0.05). A significant decrease in color match was observed in Equia restorations (p performance after 6 years. SEM evaluations were in accordance with the clinical findings. Both materials showed a good clinical performance for the restoration of posterior teeth during the 6-year evaluation. The clinical effectiveness of Equia and Gradia Direct Posterior was acceptable in Cl1 and Cl2 cavities subsequent to 6-year evaluation.

  7. Residence times of groundwater and nitrate transport in coastal aquifer systems: Daweijia area, northeastern China

    International Nuclear Information System (INIS)

    Han, Dongmei; Cao, Guoliang; McCallum, James; Song, Xianfang

    2015-01-01

    Groundwater within the coastal aquifer systems of the Daweijia area in northeastern China is characterized by a large of variations (33–521 mg/L) in NO_3"− concentrations. Elevated nitrate concentrations, in addition to seawater intrusion in the Daweijia well field, both attributable to anthropogenic activities, may impact future water-management practices. Chemical and stable isotopic (δ"1"8O, δ"2H) analysis, "3H and CFCs methods were applied to provide a better understanding of the relationship between the distribution of groundwater mean residence time (MRT) and nitrate transport, and to identify sources of nitrate concentrations in the complex coastal aquifer systems. There is a relatively narrow range of isotopic composition (ranging from − 8.5 to − 7.0‰) in most groundwater. Generally higher tritium contents observed in the wet season relative to the dry season may result from rapid groundwater circulation in response to the rainfall through the preferential flow paths. In the well field, the relatively increased nitrate concentrations of groundwater, accompanied by the higher tritium contents in the wet season, indicate the nitrate pollution can be attributed to domestic wastes. The binary exponential and piston-flow mixing model (BEP) yielded feasible age distributions based on the conceptual model. The good inverse relationship between groundwater MRTs (92–467 years) and the NO_3"− concentrations in the shallow Quaternary aquifers indicates that elevated nitrate concentrations are attributable to more recent recharge for shallow groundwater. However, there is no significant relationship between the MRTs (8–411 years) and the NO_3"− concentrations existing in the carbonate aquifer system, due to the complex hydrogeological conditions, groundwater age distributions and the range of contaminant source areas. Nitrate in the groundwater system without denitrification effects could accumulate and be transported for tens of years, through the

  8. Residence times of groundwater and nitrate transport in coastal aquifer systems: Daweijia area, northeastern China

    Energy Technology Data Exchange (ETDEWEB)

    Han, Dongmei [Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Cao, Guoliang [National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Center for Water Research, College of Engineering, Peking University, Beijing 100871 (China); McCallum, James [National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); School of the Environment, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Song, Xianfang [Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China)

    2015-12-15

    Groundwater within the coastal aquifer systems of the Daweijia area in northeastern China is characterized by a large of variations (33–521 mg/L) in NO{sub 3}{sup −} concentrations. Elevated nitrate concentrations, in addition to seawater intrusion in the Daweijia well field, both attributable to anthropogenic activities, may impact future water-management practices. Chemical and stable isotopic (δ{sup 18}O, δ{sup 2}H) analysis, {sup 3}H and CFCs methods were applied to provide a better understanding of the relationship between the distribution of groundwater mean residence time (MRT) and nitrate transport, and to identify sources of nitrate concentrations in the complex coastal aquifer systems. There is a relatively narrow range of isotopic composition (ranging from − 8.5 to − 7.0‰) in most groundwater. Generally higher tritium contents observed in the wet season relative to the dry season may result from rapid groundwater circulation in response to the rainfall through the preferential flow paths. In the well field, the relatively increased nitrate concentrations of groundwater, accompanied by the higher tritium contents in the wet season, indicate the nitrate pollution can be attributed to domestic wastes. The binary exponential and piston-flow mixing model (BEP) yielded feasible age distributions based on the conceptual model. The good inverse relationship between groundwater MRTs (92–467 years) and the NO{sub 3}{sup −} concentrations in the shallow Quaternary aquifers indicates that elevated nitrate concentrations are attributable to more recent recharge for shallow groundwater. However, there is no significant relationship between the MRTs (8–411 years) and the NO{sub 3}{sup −} concentrations existing in the carbonate aquifer system, due to the complex hydrogeological conditions, groundwater age distributions and the range of contaminant source areas. Nitrate in the groundwater system without denitrification effects could accumulate and be

  9. Groundwater arsenic content in Raigon Aquifer System (San Jose, Uruguay)

    International Nuclear Information System (INIS)

    Manay, N.; Piston, M.; Goso, C.; Fernnandez, T.; Rejas, M.; Garcia Valles, M.

    2013-01-01

    As a Medical Geology research issue, an environmental arsenic risk assessment study in the most important sedimentary aquifer in southern Uruguay is presented. The Raigon Aquifer System is the most exploited in Uruguay. It has a surface extent of about 1,800 square kilometres and 10,000 inhabitants in San Jose Department, where it was studied. Agriculture and cattle breeding are the main economic activities and this aquifer is the basic support. The groundwater sampling was done on 37 water samples of PRENADER (Natural Resources Management and Irrigation Development Program) wells. Outcropping sediments of Raigon Formation and the overlying Libertad Formation were also sampled in the Kiyu region. The analyses were performed by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS). The results showed 80% samples with arsenic levels exceeding the 10 μg/l of WHO as limit for waters, and 11% exceeds the 20 μg/l limit of uruguayan regulation. The median, maximum and minimum water arsenic concentrations determined have been 14.24, 24.19 and 1.44 μg/l, respectively. On the other hand, nine sediment samples of Raigon and Libertad Formations in Kiyu region were analysed and yielded median, maximum and minimum arsenic concentrations of 5.03, 9.82 and 1.18 ppm, respectively. This issue leads to the supposition that the population, as well as industrial and agricultural activities, are consuming water with arsenic concentrations over the national and international maximum recommended limit.

  10. Arsenic mobilization in a freshening groundwater system formed within glaciomarine deposits

    International Nuclear Information System (INIS)

    Cavalcanti de Albuquerque, R.; Kirste, D.

    2012-01-01

    Arsenic release to groundwater and conditions favoring As mobility are investigated in a system of aquifers formed within unconsolidated Quaternary sediments. The studied groundwater system is comprised of unconfined aquifers formed in glaciofluvial sediments with Ca–Mg–HCO 3 groundwater, and confined aquifers formed within glaciomarine sediments with high As (above 10 μg/L) Na–HCO 3 or Na–Cl groundwater. A positive relationship of As concentrations with the Na/(Ca + Mg) ratio of groundwater indicates that As release occurs in glaciomarine sediments concurrent to cation exchange reactions related to groundwater freshening. Arsenic is mobile in confined aquifers as a result of groundwater basic pH which prevents arsenate from adsorbing to mineral surfaces, and reducing conditions that favor speciation to arsenite. Selected extractions applied to sediment core samples indicate that As occurs in sediments predominantly in sulfide minerals and in Mn oxides and/or Fe oxyhydroxides. General positive relationships between As and the reduced species Fe 2+ , NH 3 and dissolved S 2− suggest that As release occurs at increasingly reducing conditions. Despite likely As release via Fe oxyhydroxide reductive dissolution, Fe remains at relatively low concentrations in groundwater (up to 0.37 mg/L) as a result of possible Fe adsorption and Fe reprecipitation as carbonate minerals favored by basic pH and high alkalinity. The presence of S 2− in some samples, a negative relationship between δ 34 S of SO 4 and SO 4 2- concentrations, and a positive relationship between δ 34 S and δ 18 O of SO 4 indicate that groundwater in confined aquifers is undergoing bacterial SO 4 reduction.

  11. Assessing groundwater availability and the response of the groundwater system to intensive exploitation in the North China Plain by analysis of long-term isotopic tracer data

    Science.gov (United States)

    Su, Chen; Cheng, Zhongshuang; Wei, Wen; Chen, Zongyu

    2018-03-01

    The use of isotope tracers as a tool for assessing aquifer responses to intensive exploitation is demonstrated and used to attain a better understanding of the sustainability of intensively exploited aquifers in the North China Plain. Eleven well sites were selected that have long-term (years 1985-2014) analysis data of isotopic tracers. The stable isotopes δ18O and δ2H and hydrochemistry were used to understand the hydrodynamic responses of the aquifer system, including unconfined and confined aquifers, to groundwater abstraction. The time series data of 14C activity were also used to assess groundwater age, thereby contributing to an understanding of groundwater sustainability and aquifer depletion. Enrichment of the heavy oxygen isotope (18O) and elevated concentrations of chloride, sulfate, and nitrate were found in groundwater abstracted from the unconfined aquifer, which suggests that intensive exploitation might induce the potential for aquifer contamination. The time series data of 14C activity showed an increase of groundwater age with exploitation of the confined parts of the aquifer system, which indicates that a larger fraction of old water has been exploited over time, and that the groundwater from the deep aquifer has been mined. The current water demand exceeds the sustainable production capabilities of the aquifer system in the North China Plain. Some measures must be taken to ensure major cuts in groundwater withdrawals from the aquifers after a long period of depletion.

  12. geochemical studies of groundwater systems of semiarid yola area ...

    African Journals Online (AJOL)

    DJFLEX

    formula: SAR= NA/Ca[(Ca + Mg)/2]0.5. The sodium adsorption ratio gives a clear idea about the adsorption of sodium by soil. It is the proportion of sodium to calcium and magnesium which affect the availability of the water to the crop. The sodium adsorption ratio of both surface water and groundwater obtained in the ...

  13. Groundwater contaminant plume ranking

    International Nuclear Information System (INIS)

    1988-08-01

    Containment plumes at Uranium Mill Tailings Remedial Action (UMTRA) Project sites were ranked to assist in Subpart B (i.e., restoration requirements of 40 CFR Part 192) compliance strategies for each site, to prioritize aquifer restoration, and to budget future requests and allocations. The rankings roughly estimate hazards to the environment and human health, and thus assist in determining for which sites cleanup, if appropriate, will provide the greatest benefits for funds available. The rankings are based on the scores that were obtained using the US Department of Energy's (DOE) Modified Hazard Ranking System (MHRS). The MHRS and HRS consider and score three hazard modes for a site: migration, fire and explosion, and direct contact. The migration hazard mode score reflects the potential for harm to humans or the environment from migration of a hazardous substance off a site by groundwater, surface water, and air; it is a composite of separate scores for each of these routes. For ranking the containment plumes at UMTRA Project sites, it was assumed that each site had been remediated in compliance with the EPA standards and that relict contaminant plumes were present. Therefore, only the groundwater route was scored, and the surface water and air routes were not considered. Section 2.0 of this document describes the assumptions and procedures used to score the groundwater route, and Section 3.0 provides the resulting scores for each site. 40 tabs

  14. Heuristic method for restoration of the service in electric power distribution systems

    International Nuclear Information System (INIS)

    Lemoine, Cesar Arango; Lopez Lezama, Jesus Maria; Gonzalez Londono, Monica Alejandra

    2006-01-01

    When there is an outage in a radial electrical distribution system, the isolation of the faulted section will result in the isolation of some portions of the feeder downstream from the affected area. Therefore, the next step will be to restore the service to the affected users. This restoration must be done as quickly as possible considering topology and feeder capacity restrictions. This paper describes an algorithm for service restoration via feeder reconfiguration. Results are shown under a distribution system with 11 buses and 3 main feeders

  15. Implementation Of Law Number 11 Of 2012 Concerning Child Related Criminal Justice System Concept Restorative Justice

    Directory of Open Access Journals (Sweden)

    Intan Karangan

    2016-09-01

    Full Text Available This study aims to determine how the application of the concept of restorative justice in accordance with Law No. 11 of 2012 on Child Criminal Justice system. This study uses normative namely a study that discusses the problem based on the literature and legislation relating to the matter to be investigated. Law No. 11 of 2012 on the Criminal Justice System Child has provided a new concept in the criminal justice system, especially those in the juvenile justice system. Related to the concept of Restorative Justice or restorative justice is a resolution processes involving perpetrators, victims, families, and other relevant parties in a criminal act, jointly seek solutions to the offense and its implications by emphasizing restoration and not retribution

  16. STATISTICAL INVESTIGATION OF THE GROUNDWATER SYSTEM IN DARB EL-ARBAEIN, SOUTHWESTERN DESERT, EGYPT

    Directory of Open Access Journals (Sweden)

    Kashouty Mohamed El

    2009-12-01

    Full Text Available In Darb El Arbaein, the groundwater is the only water resources. The aquifer system starts from Paleozoic-Mesozoic to Upper Cretaceous sandstone rocks. They overlay the basement rocks and the aquifer is confined. In the present research, the performance of the statistical analyses to classify groundwater samples depending on their chemical characters has been tested. The hydrogeological and hydrogeochemical data of 92 groundwater samples was obtained from the GARPAD authority in northern, central, and southern Darb El Arbaein. A robust classification scheme for partitioning groundwater chemistry into homogeneous groups was an important tool for the characterization of Nubian sandstone aquifer. We test the performance of the many available graphical and statistical methodologies used to classify water samples. R-mode, Q-mode, correlation analysis, and principal component analysis were investigated. All the methods were discussed and compared as to their ability to cluster, ease of use, and ease of interpretation. The correlation investigation clarifies the relationship among the lithology, hydrogeology, and anthropogenic. Factor investigation revealed three factors namely; the evaporation process-agriculturalimpact-lithogenic dissolution, the hydrogeological characteristics of the aquifer system, and the surface meteoric water that rechargethe aquifer system. Two main clusters that subdivided into four sub clusters were identified in groundwater system based on hydrogeological and hydrogeochemical data. They reflect the impact of geomedia, hydrogeology, geographic position, and agricultural wastewater. The groundwater is undersaturated with respect to most selected minerals. The groundwater was supersaturated with respect to iron minerals in northern and southern Darb El Arbaein. The partial pressure of CO2 of the groundwater versus saturation index of calcite shows the gradual change in PCO2 from atmospheric to the present aquifer

  17. Application of Fe-Cu/Biochar System for Chlorobenzene Remediation of Groundwater in Inhomogeneous Aquifers

    OpenAIRE

    Xu Zhang; Yanqing Wu; Pingping Zhao; Xin Shu; Qiong Zhou; Zichen Dong

    2017-01-01

    Chlorobenzene (CB), as a typical Volatile Organic Contaminants (VOC), is toxic, highly persistent and easily migrates in water, posing a significant risk to human health and subsurface ecosystems. Therefore, exploring effective approaches to remediate groundwater contaminated by CB is essential. As an enhanced micro-electrolysis system for CB-contaminated groundwater remediation, this study attempted to couple the iron-copper bimetal with biochar. Two series of columns using sands with differ...

  18. A CATASTROPHIC-CUM-RESTORATIVE QUEUING SYSTEM WITH CORRELATED BATCH ARRIVALS AND VARIABLE CAPACITY

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar

    2008-07-01

    Full Text Available In this paper, we study a catastrophic-cum-restorative queuing system with correlated batch arrivals and service in batches of variable sizes. We perform the transient analysis of the queuing model. We obtain the Laplace Transform of the probability generating function of system size. Finally, some particular cases of the model have been derived and discussed. Keywords: Queue length, Catastrophes, Correlated batch arrivals, Broadband services, Variable service capacity, and Restoration.

  19. The Evolution of Cooperation in Managed Groundwater Systems: An Agent-Based Modelling Approach

    Science.gov (United States)

    Castilla Rho, J. C.; Mariethoz, G.; Rojas, R. F.; Andersen, M. S.; Kelly, B. F.; Holley, C.

    2014-12-01

    Human interactions with groundwater systems often exhibit complex features that hinder the sustainable management of the resource. This leads to costly and persistent conflicts over groundwater at the catchment scale. One possible way to address these conflicts is by gaining a better understanding of how social and groundwater dynamics coevolve using agent-based models (ABM). Such models allow exploring 'bottom-up' solutions (i.e., self-organised governance systems), where the behaviour of individual agents (e.g., farmers) results in the emergence of mutual cooperation among groundwater users. There is significant empirical evidence indicating that this kind of 'bottom-up' approach may lead to more enduring and sustainable outcomes, compared to conventional 'top-down' strategies such as centralized control and water right schemes (Ostrom 1990). New modelling tools are needed to study these concepts systematically and efficiently. Our model uses a conceptual framework to study cooperation and the emergence of social norms as initially proposed by Axelrod (1986), which we adapted to groundwater management. We developed an ABM that integrates social mechanisms and the physics of subsurface flow. The model explicitly represents feedback between groundwater conditions and social dynamics, capturing the spatial structure of these interactions and the potential effects on cooperation levels in an agricultural setting. Using this model, we investigate a series of mechanisms that may trigger norms supporting cooperative strategies, which can be sustained and become stable over time. For example, farmers in a self-monitoring community can be more efficient at achieving the objective of sustainable groundwater use than government-imposed regulation. Our coupled model thus offers a platform for testing new schemes promoting cooperation and improved resource use, which can be used as a basis for policy design. Importantly, we hope to raise awareness of agent-based modelling as

  20. Development of a biotreatment system for the remediation of groundwater contaminated with hydrocarbons and trichloroethylene

    International Nuclear Information System (INIS)

    Folsom, B.R.; Kurisko, P.R.; Ensley, B.D.

    1992-01-01

    Inadvertent release of fuels and solvents into soil has resulted in groundwater contamination across the United States. This paper reports on the development of biologically based systems for treating mixtures of chemical contaminants which often requires knowledge of both degradative pathways and interactions between individual chemicals. These issues may necessitate the use of specialized microorganisms and/or treatment systems designed to overcome these limitations. One strategy for the treatment of chemical mixtures which cannot be source separated, such as contaminated groundwater, is a modular system to sequentially biodegrade groups of compatible chemicals. A two-stage bioreactor system was constructed for the treatment of groundwater contaminated with benzene and TCE. This treatment system is undergoing development for a field pilot demonstration. Successful implementation of this system should result in significant cost and time savings compared to competitive technologies

  1. Knowledge, transparency, and refutability in groundwater models, an example from the Death Valley regional groundwater flow system

    Science.gov (United States)

    Hill, Mary C.; Faunt, Claudia C.; Belcher, Wayne; Sweetkind, Donald; Tiedeman, Claire; Kavetski, Dmitri

    2013-01-01

    This work demonstrates how available knowledge can be used to build more transparent and refutable computer models of groundwater systems. The Death Valley regional groundwater flow system, which surrounds a proposed site for a high level nuclear waste repository of the United States of America, and the Nevada National Security Site (NNSS), where nuclear weapons were tested, is used to explore model adequacy, identify parameters important to (and informed by) observations, and identify existing old and potential new observations important to predictions. Model development is pursued using a set of fundamental questions addressed with carefully designed metrics. Critical methods include using a hydrogeologic model, managing model nonlinearity by designing models that are robust while maintaining realism, using error-based weighting to combine disparate types of data, and identifying important and unimportant parameters and observations and optimizing parameter values with computationally frugal schemes. The frugal schemes employed in this study require relatively few (10–1000 s), parallelizable model runs. This is beneficial because models able to approximate the complex site geology defensibly tend to have high computational cost. The issue of model defensibility is particularly important given the contentious political issues involved.

  2. An introduction to geographic information systems as applied to a groundwater remediation program

    International Nuclear Information System (INIS)

    Hammock, J.K.; Lorenz, R.

    1989-01-01

    While the attention to environmental issues has grown over the past several years, so has the focus on groundwater protection. Addressing the task of groundwater remediation often involves a large-scale program with numerous wells and enormous amounts of data. This data must be manipulated and analyzed in an efficient manner for the remediation program to be truly effective. Geographic Information System's (GIS) have proven to be an extremely effective tool in handling and interpreting this type of groundwater information. The purpose of this paper is to introduce the audience to GIS technology, describe how it is being used at the Savannah River Site (SRS) to handle groundwater data and demonstrate how it may be used in the corporate Westinghouse environment

  3. Microgrids for Service Restoration to Critical Load in a Resilient Distribution System

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yin; Liu, Chen-Ching; Schneider, Kevin P.; Tuffner, Francis K.; Ton, Dan T.

    2018-01-01

    icrogrids can act as emergency sources to serve critical loads when utility power is unavailable. This paper proposes a resiliency-based methodology that uses microgrids to restore critical loads on distribution feeders after a major disaster. Due to limited capacity of distributed generators (DGs) within microgrids, dynamic performance of the DGs during the restoration process becomes essential. In this paper, the stability of microgrids, limits on frequency deviation, and limits on transient voltage and current of DGs are incorporated as constraints of the critical load restoration problem. The limits on the amount of generation resources within microgrids are also considered. By introducing the concepts of restoration tree and load group, restoration of critical loads is transformed into a maximum coverage problem, which is a linear integer program (LIP). The restoration paths and actions are determined for critical loads by solving the LIP. A 4-feeder, 1069-bus unbalanced test system with four microgrids is utilized to demonstrate the effectiveness of the proposed method. The method is applied to the distribution system in Pullman, WA, resulting in a strategy that uses generators on the Washington State University campus to restore service to the Hospital and City Hall in Pullman.

  4. Deliverable 4.2-2: Stressor propagation through surface-groundwater linkages and its effect on aquatic systems

    DEFF Research Database (Denmark)

    Kaandorp, Vince; de Louw, Perry; Bloomfield, John

    2017-01-01

    The good ecological status of Europe’s freshwaters is still lacking. This paper reviews the role of groundwater in these systems and demonstrates that it is an important factor to include in surface water management. Groundwater influences streamflow, water chemistry and water temperature...... and connects rivers and streams with their catchment and thus functions as a pathway for stressors to reach the surface water. A new ‘Groundwater DPS’ framework is proposed which shows how groundwater fits in the system of a stressed aquatic ecosystem. The functioning of this framework is demonstrated using...... examples from four different European lowland catchments: the Thames, Odense, Regge and Dinkel catchments. The importance of groundwater varies between scales, between catchments and within catchments. The Groundwater DPS will aid water managers in understanding the importance of groundwater...

  5. Optimization of hybrid imaging systems based on maximization of kurtosis of the restored point spread function

    DEFF Research Database (Denmark)

    Demenikov, Mads

    2011-01-01

    to optimization results based on full-reference image measures of restored images. In comparison with full-reference measures, the kurtosis measure is fast to compute and requires no images, noise distributions, or alignment of restored images, but only the signal-to-noise-ratio. © 2011 Optical Society of America.......I propose a novel, but yet simple, no-reference, objective image quality measure based on the kurtosis of the restored point spread function. Using this measure, I optimize several phase masks for extended-depth-of-field in hybrid imaging systems and obtain results that are identical...

  6. HEIS: An integrated information system for environmental restoration and monitoring at Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Tzemos, S.; Kissinger, B.

    1991-11-01

    The US Department of Energy`s Hanford Site has about 1500 waste sites that contain a complex mixture of chemical and radioactive contaminants. After many years of environmental monitoring to assess the impact of Hanford operations to the environment, the Site`s mission is shifting to environmental restoration. The Hanford Environmental Information System (HEIS) is being developed to provide advanced tools to (1) support environmental restoration and routine site-wide monitoring, and (2) aid the scientists in understanding and conducting the restoration efforts. This paper describes some of the highlights and distinctive features of HEIS.

  7. HEIS: An integrated information system for environmental restoration and monitoring at Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Tzemos, S.; Kissinger, B.

    1991-11-01

    The US Department of Energy's Hanford Site has about 1500 waste sites that contain a complex mixture of chemical and radioactive contaminants. After many years of environmental monitoring to assess the impact of Hanford operations to the environment, the Site's mission is shifting to environmental restoration. The Hanford Environmental Information System (HEIS) is being developed to provide advanced tools to (1) support environmental restoration and routine site-wide monitoring, and (2) aid the scientists in understanding and conducting the restoration efforts. This paper describes some of the highlights and distinctive features of HEIS.

  8. Improvement of colloid sampling techniques in groundwater and actinide characterisation of the groundwater systems at Gorleben (FRG) and El Berrocal (E)

    International Nuclear Information System (INIS)

    Dearlove, J.P.L.; Longworth, G.; Ivanovich, M.

    1990-08-01

    Two sites, the Gorleben site (FRG) and the El Berrocal Experimental station (E) have been studied to evaluate different sampling and analytical techniques for the characterisation of particulates (> 1000 nm size), colloids (1-1000 nm size) and the solution phase (<1 nm) in groundwaters in terms of their physical, chemical and actinide composition. The uptake characteristics of the field ultrafiltration system used to separate the colloid fraction from the solution phase in the groundwater have also been studied. (Author)

  9. Durability of a low shrinkage TEGDMA/HEMA-free resin composite system in Class II restorations

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2017-01-01

    with a mean age of 53 years (range 29-82). Each participant received at random two, as similar as possible, Class II restorations. In the first cavity of each pair the TEGDMA/HEMA-free resin composite system was placed with its 3-step etch-and-rinse adhesive (cmf-els). In the second cavity a 1-step HEMA......Objective: The objective of this randomized controlled prospective trial was to evaluate the durability of a low shrinkage and TEGDMA/HEMA-free resin composite system in posterior restorations in a 6-year follow up. Material and methods: 139 Class II restorations were placed in 67 patients......-free self-etch adhesive was used (AdheSe One F). The restorations were evaluated using slightly modified USPHS criteria at baseline and then yearly during 6 years. Caries risk and parafunctional habits of the participants were estimated. Results: Three molar teeth showed mild post-operative sensitivity...

  10. Modelling climate change effects on a dutch coastal groundwater system using airborne electromagnetic measurements

    NARCIS (Netherlands)

    Faneca S̀anchez, M.; Gunnink, J.L.; Baaren, E.S. van; Oude Essink, G.H.P.; Siemon, B.; Auken, E.; Elderhorst, W.; Louw, P.G.B. de

    2012-01-01

    The forecast of climate change effects on the groundwater system in coastal areas is of key importance for policy makers. The Dutch water system has been deeply studied because of its complex system of low-lying areas, dunes, land won to the sea and dikes, but nowadays large efforts are still being

  11. Utilization threshold of surface water and groundwater based on the system optimization of crop planting structure

    Directory of Open Access Journals (Sweden)

    Qiang FU,Jiahong LI,Tianxiao LI,Dong LIU,Song CUI

    2016-09-01

    Full Text Available Based on the diversity of the agricultural system, this research calculates the planting structures of rice, maize and soybean considering the optimal economic-social-ecological aspects. Then, based on the uncertainty and randomness of the water resources system, the interval two-stage stochastic programming method, which introduces the uncertainty of the interval number, is used to calculate the groundwater exploitation and the use efficiency of surface water. The method considers the minimum cost of water as the objective of the uncertainty model for surface water and groundwater joint scheduling optimization for different planting structures. Finally, by calculating harmonious entropy, the optimal exploitation utilization interval of surface water and groundwater is determined for optimal cultivation in the Sanjiang Plain. The optimal matching of the planting structure under the economic system is suitable when the mining ratio of the surface is in 44.13%—45.45% and the exploitation utilization of groundwater is in 54.82%—66.86%, the optimal planting structure under the social system is suitable when surface water mining ratio is in 47.84%—48.04% and the groundwater exploitation threshold is in 67.07%—72.00%. This article optimizes the economic-social-ecological-water system, which is important for the development of a water- and food-conserving society and providing a more accurate management environment.

  12. Micropollutants in groundwater from septic systems: Transformations, transport mechanisms, and human health risk assessment.

    Science.gov (United States)

    Yang, Yun-Ya; Toor, Gurpal S; Wilson, P Chris; Williams, Clinton F

    2017-10-15

    Septic systems may contribute micropollutants to shallow groundwater and surface water. We constructed two in situ conventional drainfields (drip dispersal and gravel trench) and an advanced drainfield of septic systems to investigate the fate and transport of micropollutants to shallow groundwater. Unsaturated soil-water and groundwater samples were collected, over 32 sampling events (January 2013 to June 2014), from the drainfields (0.31-1.07 m deep) and piezometers (3.1-3.4 m deep). In addition to soil-water and groundwater, effluent samples collected from the septic tank were also analyzed for 20 selected micropollutants, including wastewater markers, hormones, pharmaceuticals and personal care products (PPCPs), a plasticizer, and their transformation products. The removal efficiencies of micropollutants from septic tank effluent to groundwater were similar among three septic systems and were 51-89% for sucralose and 53->99% for other micropollutants. Even with high removal rates within the drainfields, six PPCPs and sucralose with concentrations ranging from septic systems to ecosystem and human health is warranted for the long-term sustainability of septic systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Proceedings of the fifth international groundwater conference on the assessment and management of groundwater resources in hard rock systems with special reference to basaltic terrain

    International Nuclear Information System (INIS)

    Thangarajan, M.; Mayilswami, C.; Kulkarni, P.S.; Singh, V.P.

    2012-01-01

    Groundwater resources in hard rock regions with limited renewable potential have to be managed judiciously to ensure adequate supplies of dependable quantity and quality. It is a natural resource with economic, strategic and environmental value, which is under stress both due to changing climatic and anthropogenic factors. Therefore the management strategies need to be aimed at sustenance of this limited resource. In India, and also elsewhere in the world major parts of the semi-arid regions are characterized by hard rocks and it is of vital importance to understand the nature of the aquifer systems and its current stress conditions. Though the achievements through scientific development in exploration and exploitation are commendable, it has adversely affected the hard rock aquifer system, both in terms of quantity and quality; which is of major concern today. In order to reverse the situation, better management strategy of groundwater resources needs to be devised for prevention of further degradation of quality and meeting out the future demand of quantity. This necessitates: understanding the flow mechanism, evaluating the potential and evolving optimal utilization schemes, and assessing and monitoring quality in the changing scenario of anthropogenically induced agricultural, urban, industrial and climatic change. The groundwater flow mechanism through fractures in hard rocks is yet to be fully understood in terms of fracture geometry and its relation to groundwater flow. The characterization of flow geometry in basaltic aquifer is yet to be fully explored. Groundwater pollution due to anthropogenic factors is very slow process with long-term impacts on carbon cycle and global climatic change on one hand and quality on the other. It is generally recognized that the prevention of groundwater pollution is cheaper than its remedial measures in the long run. Furthermore, because of the nature of groundwater flow and the complexity and management uncertainty of

  14. Information system analysis of an e-learning system used for dental restorations simulation.

    Science.gov (United States)

    Bogdan, Crenguţa M; Popovici, Dorin M

    2012-09-01

    The goal of using virtual and augmented reality technologies in therapeutic interventions simulation, in the fixed prosthodontics (VirDenT) project, is to increase the quality of the educational process in dental faculties, by assisting students in learning how to prepare teeth for all-ceramic restorations. Its main component is an e-learning virtual reality-based software system that will be used for the developing skills in grinding teeth, needed in all-ceramic restorations. The complexity of the domain problem that the software system dealt with made the analysis of the information system supported by VirDenT necessary. The analysis contains the following activities: identification and classification of the system stakeholders, description of the business processes, formulation of the business rules, and modelling of business objects. During this stage, we constructed the context diagram, the business use case diagram, the activity diagrams and the class diagram of the domain model. These models are useful for the further development of the software system that implements the VirDenT information system. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  15. Classification as a generic tool for characterising status and changes of regional scale groundwater systems

    Science.gov (United States)

    Barthel, Roland; Haaf, Ezra

    2016-04-01

    Regional hydrogeology is becoming increasingly important, but at the same time, scientifically sound, universal solutions for typical groundwater problems encountered on the regional scale are hard to find. While managers, decision-makers and state agencies operating on regional and national levels have always shown a strong interest in regional scale hydrogeology, researchers from academia tend to avoid the subject, focusing instead on local scales. Additionally, hydrogeology has always had a tendency to regard every problem as unique to its own site- and problem-specific context. Regional scale hydrogeology is therefore pragmatic rather than aiming at developing generic methodology (Barthel, 2014; Barthel and Banzhaf, 2016). One of the main challenges encountered on the regional scale in hydrogeology is the extreme heterogeneity that generally increases with the size of the studied area - paired with relative data scarcity. Even in well-monitored regions of the world, groundwater observations are usually clustered, leaving large areas without any direct data. However, there are many good reasons for assessing the status and predicting the behavior of groundwater systems under conditions of global change even for those areas and aquifers without observations. This is typically done by using rather coarsely discretized and / or poorly parameterized numerical models, or by using very simplistic conceptual hydrological models that do not take into account the complex three-dimensional geological setup. Numerical models heavily rely on local data and are resource-demanding. Conceptual hydrological models only deliver reliable information on groundwater if the geology is extremely simple. In this contribution, we present an approach to derive statistically relevant information for un-monitored areas, making use of existing information from similar localities that are or have been monitored. The approach combines site-specific knowledge with conceptual assumptions on

  16. A Systems Thinking approach to post-disaster restoration of maritime transportation systems

    Science.gov (United States)

    Lespier, Lizzette Pérez; Long, Suzanna K.; Shoberg, Thomas G.

    2015-01-01

    A Systems Thinking approach is used to examine elements of a maritime transportation system that are most likely to be impacted by an extreme event. The majority of the literature uses a high-level view that can fail to capture the damage at the sub-system elements. This work uses a system dynamics simulation for a better view and understanding of the Port of San Juan, Puerto Rico, as a whole system and uses Hurricane Georges (1998), as a representative disruptive event. The model focuses on the impacts of natural disasters at the sub-system level with a final goal of determining the sequence needed to restore an ocean-going port to its pre-event state. This work in progress details model development and outlines steps for using real-world information to assist maritime port manager planning and recommendations for best practices to mitigate disaster damage.

  17. Complexity in the validation of ground-water travel time in fractured flow and transport systems

    International Nuclear Information System (INIS)

    Davies, P.B; Hunter, R.L.; Pickens, J.F.

    1991-02-01

    Ground-water travel time is a widely used concept in site assessment for radioactive waste disposal. While ground-water travel time was originally conceived to provide a simple performance measure for evaluating repository sites, its definition in many flow and transport environments is ambiguous. The US Department of Energy siting guidelines (10 CFR 960) define ground-water travel time as the time required for a unit volume of water to travel between two locations, calculated by dividing travel-path length by the quotient of average ground-water flux and effective porosity. Defining a meaningful effective porosity in a fractured porous material is a significant problem. Although the Waste Isolation Pilot Plant (WIPP) is not subject to specific requirements for ground-water travel time, travel times have been computed under a variety of model assumptions. Recently completed model analyses for WIPP illustrate the difficulties in applying a ground-water travel-time performance measure to flow and transport in fractured, fully saturated flow systems. 12 refs., 4 figs

  18. Assessment of groundwater quality using geographical information system (GIS), at north-east Cairo, Egypt.

    Science.gov (United States)

    El-Shahat, M F; Sadek, M A; Mostafa, W M; Hagagg, K H

    2016-04-01

    The present investigation has been conducted to delineate the hydrogeochemical and environmental factors that control the water quality of the groundwater resources in the north-east of Cairo. A complementary approach based on hydrogeochemistry and a geographical information system (GIS) based protectability index has been employed for conducting this work. The results from the chemical analysis revealed that the groundwater of the Quaternary aquifer is less saline than that of the Miocene aquifer and the main factors that control the groundwater salinity in the studied area are primarily related to the genesis of the original recharging water modified after by leaching, dissolution, cation exchange, and fertilizer leachate. The computed groundwater quality index (WQI) falls into two categories: fair for almost all the Miocene groundwater samples, while the Quaternary groundwater samples are all have a good quality. The retarded flow and non-replenishment of the Miocene aquifer compared to the renewable active recharge of the Quaternary aquifer can explain this variation of WQI. The index and overlay approach exemplified by the DUPIT index has been used to investigate the protectability of the study aquifers against diffuse pollutants. Three categories (highly protectable less vulnerable, moderately protectable moderately vulnerable and less protectable highly vulnerable) have been determined and areally mapped.

  19. Complexity in the validation of ground-water travel time in fractured flow and transport systems

    International Nuclear Information System (INIS)

    Davies, P.B.; Hunter, R.L.; Pickens, J.F.

    1991-01-01

    Ground-water travel time is a widely used concept in site assessment for radioactive waste disposal. While ground-water travel time was originally conceived to provide a simple performance measure for evaluating repository sites, its definition in many flow and transport environments is ambiguous. The U.S. Department of Energy siting guidelines (10 CFR 960) define ground-water travel time as the time required for a unit volume of water to travel between two locations, calculated by dividing travel-path length by the quotient of average ground-water flux and effective porosity. Defining a meaningful effective porosity in a fractured porous material is a significant problem. Although the Waste Isolation Pilot Plant (WIPP) is not subject to specific requirements for ground-water travel time, travel times have been computed under a variety of model assumptions. Recently completed model analyses for WIPP illustrate the difficulties in applying a ground-water travel-time performance measure to flow and transport in fractured, fully saturated flow systems. Computer code used: SWIFT II (flow and transport code). 4 figs., 12 refs

  20. Groundwater quality monitoring well installation for Lower Waste Area Grouping 2 at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program

    International Nuclear Information System (INIS)

    Mortimore, J.A.; Lee, T.A.

    1994-09-01

    This report documents the drilling and installation of 11 groundwater quality monitoring (GQM) wells on the perimeter of Lower Waste Area Grouping (WAG) 2. Lower WAG 2 consists of White Oak Lake and the embayment below White Oak Dam above the Clinch River. The wells in Lower WAG 2 were drilled and developed between December 1989 and September 1990. These wells were installed to characterize and assess the WAG in accordance with applicable Department of Energy, state, and Environmental Protection Agency regulatory requirements. The wells at Lower WAG 2 were drilled with auger or air rotary rigs. Depending on the hydrogeologic conditions present at each proposed well location, one of three basic installation methods was utilized. Detailed procedures for well construction were specified by the Engineering Division to ensure that the wells would provide water samples representative of the aquifer. To ensure conformance with the specifications, Energy Systems Construction Engineering and ERCE provided continuous oversight of field activities. The purpose of the well installation program was to install GQM wells for groundwater characterization at Lower WAG 2. Data packages produced during installation activities by the ERCE hydrogeologists are an important product of the program. These packages document the well drilling, installation, and development activities and provide valuable data for well sampling and WAG characterization. The forms contained in the packages include predrilling and postdrilling checklists, drilling and construction logs, development and hydraulic conductivity records, and quality control-related documents

  1. Simultaneous caving and surface restoration system for oil shale mining

    Energy Technology Data Exchange (ETDEWEB)

    Allsman, P.T.

    1968-10-01

    A modified caving method is introduced for mining oil shale and simultaneous restoration of the land surface by return of spent shale onto the subsided area. Other methods have been designed to mine the relatively thin richer beds occurring near outcrops in the Piceance Creek Basin of NW. Colorado. Since the discovery of the much thicker beds in the N.-central part of the basin, some attention has focused on in situ and open-pit methods of recovery. Although caving has been recognized as a possible means of mining shale, most people have been skeptical of its success. This stems from the unknown and salient factors of cavability and size of broken rock with caving. Wisdom would seem to dictate that serious evaluation of the caving method be made along with the other methods.

  2. Hydrogeological controls on spatial patterns of groundwater discharge in peatlands

    Directory of Open Access Journals (Sweden)

    D. K. Hare

    2017-11-01

    Full Text Available Peatland environments provide important ecosystem services including water and carbon storage, nutrient processing and retention, and wildlife habitat. However, these systems and the services they provide have been degraded through historical anthropogenic agricultural conversion and dewatering practices. Effective wetland restoration requires incorporating site hydrology and understanding groundwater discharge spatial patterns. Groundwater discharge maintains wetland ecosystems by providing relatively stable hydrologic conditions, nutrient inputs, and thermal buffering important for ecological structure and function; however, a comprehensive site-specific evaluation is rarely feasible for such resource-constrained projects. An improved process-based understanding of groundwater discharge in peatlands may help guide ecological restoration design without the need for invasive methodologies and detailed site-specific investigation. Here we examine a kettle-hole peatland in southeast Massachusetts historically modified for commercial cranberry farming. During the time of our investigation, a large process-based ecological restoration project was in the assessment and design phases. To gain insight into the drivers of site hydrology, we evaluated the spatial patterning of groundwater discharge and the subsurface structure of the peatland complex using heat-tracing methods and ground-penetrating radar. Our results illustrate that two groundwater discharge processes contribute to the peatland hydrologic system: diffuse lower-flux marginal matrix seepage and discrete higher-flux preferential-flow-path seepage. Both types of groundwater discharge develop through interactions with subsurface peatland basin structure, often where the basin slope is at a high angle to the regional groundwater gradient. These field observations indicate strong correlation between subsurface structures and surficial groundwater discharge. Understanding these general patterns

  3. Hydrogeological controls on spatial patterns of groundwater discharge in peatlands

    Science.gov (United States)

    Hare, Danielle K.; Boutt, David F.; Clement, William P.; Hatch, Christine E.; Davenport, Glorianna; Hackman, Alex

    2017-11-01

    Peatland environments provide important ecosystem services including water and carbon storage, nutrient processing and retention, and wildlife habitat. However, these systems and the services they provide have been degraded through historical anthropogenic agricultural conversion and dewatering practices. Effective wetland restoration requires incorporating site hydrology and understanding groundwater discharge spatial patterns. Groundwater discharge maintains wetland ecosystems by providing relatively stable hydrologic conditions, nutrient inputs, and thermal buffering important for ecological structure and function; however, a comprehensive site-specific evaluation is rarely feasible for such resource-constrained projects. An improved process-based understanding of groundwater discharge in peatlands may help guide ecological restoration design without the need for invasive methodologies and detailed site-specific investigation. Here we examine a kettle-hole peatland in southeast Massachusetts historically modified for commercial cranberry farming. During the time of our investigation, a large process-based ecological restoration project was in the assessment and design phases. To gain insight into the drivers of site hydrology, we evaluated the spatial patterning of groundwater discharge and the subsurface structure of the peatland complex using heat-tracing methods and ground-penetrating radar. Our results illustrate that two groundwater discharge processes contribute to the peatland hydrologic system: diffuse lower-flux marginal matrix seepage and discrete higher-flux preferential-flow-path seepage. Both types of groundwater discharge develop through interactions with subsurface peatland basin structure, often where the basin slope is at a high angle to the regional groundwater gradient. These field observations indicate strong correlation between subsurface structures and surficial groundwater discharge. Understanding these general patterns may allow resource

  4. Use of digital impression systems with intraoral scanners for fabricating restorations and fixed dental prostheses.

    Science.gov (United States)

    Takeuchi, Yoshimasa; Koizumi, Hiroyasu; Furuchi, Mika; Sato, Yohei; Ohkubo, Chikahiro; Matsumura, Hideo

    2018-01-01

    Accurate impressions are essential in fabri-cating dental restorations and fixed dental prostheses. During the last decade, digital impression systems have improved substantially. This review discusses the accuracy of digital impression systems for fabrication of dental restorations and fixed dental prostheses. A literature search in PubMed was performed for the period from July 2010 through June 2017. The search keywords were Cerec, digital impression, direct digitalization, indirect digitalization, and intraoral scanner. Only relevant studies are summarized and discussed in this review. In general, the latest systems have considerably reduced the time required for impression making, and the accuracy and marginal fit of digital impression systems have recently improved. Restorations and fixed dental prostheses fabricated with currently available digital impression systems and intraoral scanners exhibit clinically acceptable ranges of marginal gap in both direct and indirect procedures.

  5. Ground-Water Budgets for the Wood River Valley Aquifer System, South-Central Idaho, 1995-2004

    Science.gov (United States)

    Bartolino, James R.

    2009-01-01

    five main sources (from largest to smallest): Silver Creek streamflow gain, ground-water pumpage, Big Wood River streamflow gain, direct evapotranspiration from riparian vegetation, and subsurface outflow (treated separately). Total estimated mean 1995-2004 annual outflow or discharge from the aquifer system is 250,000 acre-ft/yr (350 ft3/s). Estimated total discharge is 240,000 acre-ft/yr (330 ft3/s) for both the wet year 1995 and the dry year 2001. The budget residual is the difference between estimated ground-water inflow and outflow and encompasses subsurface outflow, ground-water storage change, and budget error. For 1995-2004, mean annual inflow exceeded outflow by 20,000 acre-ft/yr (28 ft3/s); for the wet year 1995, mean annual inflow exceeded outflow by 30,000 acre-ft/yr (41 ft3/s); for the dry year 2001, mean annual outflow exceeded inflow by 20,000 acre-ft/yr (28 ft3/s). These values represent 8, 13, and 8 percent, respectively, of total outflows for the same periods. It is difficult to differentiate the relative contributions of the three residual components, although the estimated fluctuations between the wet and dry year budgets likely are primarily caused by changes in ground-water storage. The individual components in the wet and dry year ground-water budgets responded in a consistent manner to changes in precipitation and temperature. Although the ground-water budgets for the three periods indicated that ground-water storage is replenished in wet years, statistical analyses by Skinner and others (2007) suggest that such replenishment is not complete and over the long term more water is removed from storage than is replaced. In other words, despite restoration of water to ground-water storage in wet years, changes have occurred in either recharge and (or) discharge to cause ground-water storage to decline over time. Such changes may include, but are not limited to: lining or abandoning canals and ditches, conversion of surface-water irriga

  6. Geochemical and isotopic determination of deep groundwater contributions and salinity to the shallow groundwater and surface water systems, Mesilla Basin, New Mexico, Texas, and Mexico

    Science.gov (United States)

    Robertson, A.; Carroll, K. C.; Kubicki, C.; Purtshert, R.

    2017-12-01

    The Mesilla Basin/Conejos-Médanos aquifer system, extending from southern New Mexico to Chihuahua, Mexico, is a priority transboundary aquifer under the 2006 United States­-Mexico Transboundary Aquifer Assessment Act. Declining water levels, deteriorating water quality, and increasing groundwater use by municipal, industrial, and agricultural users on both sides of the international border raise concerns about long-term aquifer sustainability. Relative contributions of present-day and "paleo" recharge to sustainable fresh groundwater yields has not been determined and evidence suggests that a large source of salinity at the distal end of the Mesilla Basin is saline discharge from deep groundwater flow. The magnitude and distribution of those deep saline flow paths are not determined. The contribution of deep groundwater to discharge and salinity in the shallow groundwater and surface water of the Mesilla Basin will be determined by collecting discrete groundwater samples and analyzing for aqueous geochemical and isotopic tracers, as well as the radioisotopes of argon and krypton. Analytes include major ions, trace elements, the stable isotopes of water, strontium and boron isotopes, uranium isotopes, the carbon isotopes of dissolved inorganic carbon, noble gas concentrations and helium isotope ratios. Dissolved gases are extracted and captured from groundwater wells using membrane contactors in a process known as ultra-trace sampling. Gas samples are analyzed for radioisotope ratios of krypton by the ATTA method and argon by low-level counting. Effectiveness of the ultra-trace sampling device and method was evaluated by comparing results of tritium concentrations to the krypton-85 content. Good agreement between the analyses, especially in samples with undetectable tritium, indicates that the ultra-trace procedure is effective and confirms that introduction of atmospheric air has not occurred. The geochemistry data indicate a complex system of geochemical

  7. Environmental Sciences Division Groundwater Program Office

    International Nuclear Information System (INIS)

    1993-01-01

    This first edition of the Martin Marietta Energy Systems, Inc., (Energy Systems) Groundwater Program Annual Report summarizes the work carried out by the Energy Systems GWPO for fiscal year (FY) 1993. This introductory section describes the GWPO's staffing, organization, and funding sources. The GWPO is responsible for coordination and oversight for all components of the groundwater program at the three Oak Ridge facilities [ORNL, the Oak Ridge Y-12 Plant, and the Oak Ridge K-25 Site], and the PGDP and PORTS, respectively. Several years ago, Energy systems senior management recognized that the manner in which groundwater activities were conducted at the five facilities could result in unnecessary duplication of effort, inadequate technical input to decisions related to groundwater issues, and could create a perception within the regulatory agencies of a confusing and inconsistent approach to groundwater issues at the different facilities. Extensive interactions among management from Environmental Compliance, Environmental Restoration (ER), Environmental Sciences Division, Environmental Safety and Health, and the five facilities ultimately led to development of a net technical umbrella organization for groundwater. On April 25, 1991, the GWPO was authorized to be set up within ORNL thereby establishing a central coordinating office that would develop a consistent technical and administrative direction for the groundwater programs of all facilities and result in compliance with all relevant U.S. Environmental Protection Agency (EPA) regulations such as RCRA and Comprehensive Environmental Restoration, Compensation and Liability Act (CERCLA) as well as U.S. Department of Energy (DOE) regulations and orders. For example, DOE Order 5400.1, issued on November 9, 1988, called for each DOE facility to develop an environmental monitoring program for all media (e.g., air, surface water, and groundwater)

  8. Role of native and exotic woody vegetation in soil restoration in active gully systems (southern Ecuador)

    Science.gov (United States)

    Borja Ramon, Pablo; Alvarado Moncayo, Dario; Vanacker, Veerle; Cisneros, Pedro; Molina, Armando; Govers, Gerard

    2015-04-01

    Revegetation projects in degraded lands have the potential to recover essential soil functions. If vegetation restoration is combined with bioengineering techniques, such as the construction of retention dams in active gully systems, soil restoration could be enhanced. One important aspect of this process is the role of vegetation on restoration of soil chemical and physical properties. There is currently a lack of knowledge on the potential of soil restoration in active badland systems, as most studies have concentrated on the direct and visible effect of revegetation on erosion control. The aim of this study is to evaluate the role of revegetation and bioengineering works on the restoration of soil physical and chemical properties. The analyses are realized in a highly degraded area of 3 km2, located in the lower part of the Loreto catchment (Southern Ecuadorian Andes). First, the soil physical and/or chemical parameters that are most sensitive to track environmental change were evaluated. Second, the role of vegetation on soil restoration was quantified. . Soil samples were taken in sites with different vegetation cover, land use and physiographic position. The following physical and chemical parameters were measured: volumetric water content (θsat, θact), bulk density, pH, texture, organic matter, C and N content. Our first results do not show a clear relationship between volumetric water content at saturation (θsat), bulk density, or C content. The saturation water content does not vary significantly between different sites, or land use types. However, significant differences are found between sites at different stages of restoration; and this for most chemical and physical soil properties. Vegetation cover (%) appears to exert a strong control on the C content in the mineral soils. The highest C values are found in soils of forest plantations with Eucalyptus and Pinus species. These plantations are located in areas that were previously affected by active

  9. Quality of groundwater in the Denver Basin aquifer system, Colorado, 2003-5

    Science.gov (United States)

    Musgrove, MaryLynn; Beck, Jennifer A.; Paschke, Suzanne; Bauch, Nancy J.; Mashburn, Shana L.

    2014-01-01

    Groundwater resources from alluvial and bedrock aquifers of the Denver Basin are critical for municipal, domestic, and agricultural uses in Colorado along the eastern front of the Rocky Mountains. Rapid and widespread urban development, primarily along the western boundary of the Denver Basin, has approximately doubled the population since about 1970, and much of the population depends on groundwater for water supply. As part of the National Water-Quality Assessment Program, the U.S. Geological Survey conducted groundwater-quality studies during 2003–5 in the Denver Basin aquifer system to characterize water quality of shallow groundwater at the water table and of the bedrock aquifers, which are important drinking-water resources. For the Denver Basin, water-quality constituents of concern for human health or because they might otherwise limit use of water include total dissolved solids, fluoride, sulfate, nitrate, iron, manganese, selenium, radon, uranium, arsenic, pesticides, and volatile organic compounds. For the water-table studies, two monitoring-well networks were installed and sampled beneath agricultural (31 wells) and urban (29 wells) land uses at or just below the water table in either alluvial material or near-surface bedrock. For the bedrock-aquifer studies, domestic- and municipal-supply wells completed in the bedrock aquifers were sampled. The bedrock aquifers, stratigraphically from youngest (shallowest) to oldest (deepest), are the Dawson, Denver, Arapahoe, and Laramie-Fox Hills aquifers. The extensive dataset collected from wells completed in the bedrock aquifers (79 samples) provides the opportunity to evaluate factors and processes affecting water quality and to establish a baseline that can be used to characterize future changes in groundwater quality. Groundwater samples were analyzed for inorganic, organic, isotopic, and age-dating constituents and tracers. This report discusses spatial and statistical distributions of chemical constituents

  10. Installation of reactive metals groundwater collection and treatment systems

    International Nuclear Information System (INIS)

    Hopkins, J.K.; Primrose, A.L.; Uhland, J.

    1998-01-01

    Three groundwater plumes contaminated with volatile organic compounds (VOCs) and radionuclides at the Rocky Flats Environmental Technology Site are scheduled for remediation by 1999 based on the Rocky Flats Cleanup Agreement (RFCA) (DOE, 1996). These three plumes are among the top 20 environmental cleanup sites at Rocky Flats. One of these plumes, the Mound Site Plume, is derived from a previous drum storage area, and daylights as seeps near the South Walnut Creek drainage. Final design for remediation of the Mound Site Plume has been completed based on use of reactive metals to treat the contaminated groundwater, and construction is scheduled for early 1998. The two other plumes, the 903 Pad/Ryan's Pit and the East Trenches Plumes, are derived from VOCs either from drums that leaked or that were disposed of in trenches. These two plumes are undergoing characterization and conceptual design in 1998 and construction is scheduled in 1999. The contaminants of concern in these plumes are tetrachloroethene, trichloroethene, carbon tetrachloride and low levels of uranium and americium

  11. Boundary delineation for regional groundwater flow through geographic information system (Contract research)

    International Nuclear Information System (INIS)

    Yamakawa, Tadashi; Munakata, Masahiro; Kimura, Hideo; Hyodo, Hiroshi

    2007-03-01

    Radionuclide migration toward the human environment is to be assessed as the part of long-term safety assessments of geologic disposal of radioactive waste. Geologic processes, which include volcanic activity, hydrothermal activity, seismicity and deformation, bring about hydrogeologic changes in the regional groundwater flow system around a repository site. Groundwater flow systems in Japan have been studied in several sites such as Tono mine, Kamaishi mine and Horonobe area, but methodology of studies in these sites does not have fully developed. This study was conducted to develop methodologies of boundary delineation for regional groundwater flow systems. Geographic Information System, GIS, was applied using available topographic, hydrologic and geologic data for an area of interest. Miyakoji in the Abukuma Mountains was selected as the area, for the reason of its simple geologic setting formed by granitic rocks and topographically gentle hills of drainage basin. Data used in this study cover topographic sheets, digital elevation model, satellite imagery, geologic maps, topographic classification maps, soil distribution maps and landuse maps. Through the GIS techniques using these data, thematic maps on topographic features, surface conditions, land coverage, geology and geologic structure and weathered crust were developed, and these thematic maps were further applied to extract four factors affecting the regional groundwater flows: topographic condition, precipitation recharge, fracture characteristics and potential flows. The present study revealed that, taking the potential groundwater flows and characteristics of fractured zones in the area into consideration, the groundwater flow system in Miyakoji drainage basin should be bounded by the Otakine Mountain and the northern part of Tokoha Drainage Basin. The delineated area is larger than understood before. (author)

  12. Towards a decision support system for stream restoration in the Netherlands: an overview of restoration projects and future needs

    NARCIS (Netherlands)

    Verdonschot, P.F.M.; Nijboer, R.C.

    2002-01-01

    Stream restoration is one of the answers to the lowland stream deterioration. For making proper choices in stream restoration, one firstly needs to understand the complex spatial and temporal interactions between physical, chemical and biological components in the stream ecosystem. Several

  13. Assessment of groundwater recharge and water fluxes of the Guarani Aquifer System, Brazil

    Science.gov (United States)

    Rabelo, Jorge Luiz; Wendland, Edson

    2009-11-01

    The groundwater recharge and water fluxes of the Guarani Aquifer System in the state of Sao Paulo in Brazil were assessed through a numeric model. The study area (6,748 km2) comprises Jacaré-Guaçú and Jacaré-Pepira River watersheds, tributaries of the Tietê River in the central region of the state. GIS based tools were used in the storage, processing and analysis of data. Main hydrologic phenomena were selected, leading to a groundwater conceptual model, taking into account the significant outcrops occurring in the study area. Six recharge zones were related to the geologic formation and structures of the semi-confined and phreatic aquifer. The model was calibrated against the baseflows and static water levels of the wells. The results emphasize the strong interaction of groundwater flows between watersheds and the groundwater inflow into the rivers. It has been concluded that lateral groundwater exchanges between basins, the deep discharges to the regional system, and well exploitation were not significant aquifer outflows when compared to the aquifer recharge. The results have shown that the inflows from the river into the aquifer are significant and have the utmost importance since the aquifer is potentially more vulnerable in these places.

  14. Quantifying changes in water use and groundwater availability in a megacity using novel integrated systems modeling

    Science.gov (United States)

    Hyndman, D. W.; Xu, T.; Deines, J. M.; Cao, G.; Nagelkirk, R.; Viña, A.; McConnell, W.; Basso, B.; Kendall, A. D.; Li, S.; Luo, L.; Lupi, F.; Ma, D.; Winkler, J. A.; Yang, W.; Zheng, C.; Liu, J.

    2017-08-01

    Water sustainability in megacities is a growing challenge with far-reaching effects. Addressing sustainability requires an integrated, multidisciplinary approach able to capture interactions among hydrology, population growth, and socioeconomic factors and to reflect changes due to climate variability and land use. We developed a new systems modeling framework to quantify the influence of changes in land use, crop growth, and urbanization on groundwater storage for Beijing, China. This framework was then used to understand and quantify causes of observed decreases in groundwater storage from 1993 to 2006, revealing that the expansion of Beijing's urban areas at the expense of croplands has enhanced recharge while reducing water lost to evapotranspiration, partially ameliorating groundwater declines. The results demonstrate the efficacy of such a systems approach to quantify the impacts of changes in climate and land use on water sustainability for megacities, while providing a quantitative framework to improve mitigation and adaptation strategies that can help address future water challenges.

  15. Composition of Groundwater Bacterial Communities before and after Air Surging in a Groundwater Heat Pump System According to a Pyrosequencing Assay

    Directory of Open Access Journals (Sweden)

    Heejung Kim

    2017-11-01

    Full Text Available The geothermal energy of groundwater has aroused increasing interest as a solution to climate change. The groundwater heat pumps (GWHP system using groundwater is the most environmentally friendly system to date and has been examined in several studies. However, biological clogging by microorganisms negatively affects the thermal efficiency of the GWHP system. In this study, we employed air surging, the most popular among well management methods, and pyrosequencing to analyze the genetic diversity in bacteria before and after air surging in a geothermal well. Furthermore, the diversity of dominant bacterial genera and those related to clogging were evaluated. The bacterial diversity of the groundwater well increased after air surging. Nevertheless, the proportion of bacterial genera thought to be related to microbiological clogging decreased. In cooling and heating systems based on the geothermal energy of groundwater, the wells should be maintained regularly by air surging to reduce efficiency problems caused by microbiological clogging and to prevent secondary damage to human health, e.g., pneumonia due to human pathogenic bacteria including Pseudomonas aeruginosa and Acinetobacter.

  16. A General Solution for Groundwater Flow in Estuarine Leaky Aquifer System with Considering Aquifer Anisotropy

    Science.gov (United States)

    Chen, Po-Chia; Chuang, Mo-Hsiung; Tan, Yih-Chi

    2014-05-01

    In recent years the urban and industrial developments near the coastal area are rapid and therefore the associated population grows dramatically. More and more water demand for human activities, agriculture irrigation, and aquaculture relies on heavy pumping in coastal area. The decline of groundwater table may result in the problems of seawater intrusion and/or land subsidence. Since the 1950s, numerous studies focused on the effect of tidal fluctuation on the groundwater flow in the coastal area. Many studies concentrated on the developments of one-dimensional (1D) and two-dimensional (2D) analytical solutions describing the tide-induced head fluctuations. For example, Jacob (1950) derived an analytical solution of 1D groundwater flow in a confined aquifer with a boundary condition subject to sinusoidal oscillation. Jiao and Tang (1999) derived a 1D analytical solution of a leaky confined aquifer by considered a constant groundwater head in the overlying unconfined aquifer. Jeng et al. (2002) studied the tidal propagation in a coupled unconfined and confined costal aquifer system. Sun (1997) presented a 2D solution for groundwater response to tidal loading in an estuary. Tang and Jiao (2001) derived a 2D analytical solution in a leaky confined aquifer system near open tidal water. This study aims at developing a general analytical solution describing the head fluctuations in a 2D estuarine aquifer system consisted of an unconfined aquifer, a confined aquifer, and an aquitard between them. Both the confined and unconfined aquifers are considered to be anisotropic. The predicted head fluctuations from this solution will compare with the simulation results from the MODFLOW program. In addition, the solutions mentioned above will be shown to be special cases of the present solution. Some hypothetical cases regarding the head fluctuation in costal aquifers will be made to investigate the dynamic effects of water table fluctuation, hydrogeological conditions, and

  17. Budgets and chemical characterization of groundwater for the Diamond Valley flow system, central Nevada, 2011–12

    Science.gov (United States)

    Berger, David L.; Mayers, C. Justin; Garcia, C. Amanda; Buto, Susan G.; Huntington, Jena M.

    2016-07-29

    The Diamond Valley flow system consists of six hydraulically connected hydrographic areas in central Nevada. The general down-gradient order of the areas are southern and northern Monitor Valleys, Antelope Valley, Kobeh Valley, Stevens Basin, and Diamond Valley. Groundwater flow in the Diamond Valley flow system terminates at a large playa in the northern part of Diamond Valley. Concerns relating to continued water-resources development of the flow system resulted in a phased hydrologic investigation that began in 2005 by the U.S. Geological Survey in cooperation with Eureka County. This report presents the culmination of the phased investigation to increase understanding of the groundwater resources of the basin-fill aquifers in the Diamond Valley flow system through evaluations of groundwater chemistry and budgets. Groundwater chemistry was characterized using major ions and stable isotopes from groundwater and precipitation samples. Groundwater budgets accounted for all inflows, outflows, and changes in storage, and were developed for pre-development (pre-1950) and recent (average annual 2011–12) conditions. Major budget components include groundwater discharge by evapotranspiration and groundwater withdrawals; groundwater recharge by precipitation, and interbasin flow; and storage change.

  18. Iodine speciation and diffusion in a sand-groundwater system

    International Nuclear Information System (INIS)

    Higgo, J.J.W.; Haigh, D.G.; Allen, M.R.; Williams, G.M.; Warwick, P.

    1991-01-01

    This study lies within the Mirage II research programme (migration of radionuclides in the geosphere) set up by the Commission of the European Communities and supported by the UK Department of the Environment. The work forms part of the project entilled In situ determination of the effects of organics on the mobility of radionuclides in controlled conditions of groundwater flow which is being carried out by the British Geological Survey at Drigg in Cumbria, on land owned by British Nuclear Fuel plc. The study involves the detailed geochemical and hydrogeological characterization of a confined aquifer of glacial sand, the laboratory scale investigation of radionuclide sorption processes and how these are affected by the presence of natural and anthropogenic organic compounds. Ultimately the results of field hydraulic testing and laboratory studies of radionuclide sorption will be used to predict the outcome of a field tracer experiment using conservative and reactive radionuclide species

  19. Autoradiographic studies of actinide sorption in groundwater systems

    International Nuclear Information System (INIS)

    O'Kelley, G.D.; Beall, G.W.; Allard, B.

    1980-01-01

    Autoradiography is a convenient and sensitive technique for the study of spacial distributions of alpha radioactive nuclides on slabs of rock or on other planar surfaces. The autoradiographic camera contains an arrangement for placing in firm contact Polaroid sheet film, a plastic scintillator screen, and the radioactive face of the specimen. As an example of the use of the autoradiographic method, a series of sorption experiments were carried out in which synthetic groundwater solutions of americium, neptunium, uranium, and plutonium were contacted with Climax Stock granite under aerated and anoxic conditions at pH 8 to 9. The sorption observed at specific mineral sites was correlated with data on sorption of these actinides on pure minerals

  20. Selection of Non-Restorable Reserved Energy Process Control and Management Systems

    Directory of Open Access Journals (Sweden)

    V. A. Anischenko

    2012-01-01

    Full Text Available The paper considers problems pertaining to selection of non-restorable continuously reserved discrete control and management systems of electric and heat and power processes. Two problems concerning system optimization on the basis of the following criteria – their reliability and cost have been solved in the paper. 

  1. Strontium isotope geochemistry of groundwater affected by human activities in Nandong underground river system, China

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Yongjun, E-mail: jiangjyj@swu.edu.cn [School of Geographical Sciences, Southwest University, Chongqing 400715 (China)] [Institute of Karst Environment and Rock Desertification Rehabilitation, Chongqing 400715 (China)

    2011-03-15

    Research highlights: {yields} Spatio-temporal variations of Sr concentrations and Sr isotopic composition of groundwater were investigated in a karst underground river system. {yields} Agricultural fertilizers and sewage effluents significantly modified the natural Sr isotopic signature of karst groundwater. {yields} Sr in the carbonate aquifers was relatively non-radiogenic, with low Sr concentrations, while anthropogenic Sr correlated with agricultural fertilizers and sewage effluents was relatively radiogenic, with higher Sr concentrations. {yields} {sup 87}Sr/{sup 86}Sr ratios can provide key information for natural and anthropogenic sources in karst groundwater. - Abstract: The Nandong Underground River System (NURS) is located in a typical karst area dominated by agriculture in SE Yunnan Province, China. Groundwater plays an important role in the social and economical development in the area. The effects of human activities (agriculture and sewage effluents) on the Sr isotope geochemistry were investigated in the NURS. Seventy-two representative groundwater samples, which were collected from different aquifers (calcite and dolomite), under varying land-use types, both in summer and winter, showed significant spatial differences and slight seasonal variations in Sr concentrations and {sup 87}Sr/{sup 86}Sr ratios. Agricultural fertilizers and sewage effluents significantly modified the natural {sup 87}Sr/{sup 86}Sr ratios signature of groundwater that was otherwise dominated by water-rock interaction. Three major sources of Sr could be distinguished by {sup 87}Sr/{sup 86}Sr ratios and Sr concentrations in karst groundwater. Two sources of Sr are the Triassic calcite and dolomite aquifers, where waters have low Sr concentrations (0.1-0.2 mg/L) and low {sup 87}Sr/{sup 86}Sr ratios (0.7075-0.7080 and 0.7080-0.7100, respectively); the third source is anthropogenic Sr from agricultural fertilizers and sewage effluents with waters affected having radiogenic {sup 87

  2. The Relevance of the Doctrine on Restorative Justice in the Indonesian Sentencing System

    Directory of Open Access Journals (Sweden)

    Bambang Waluyo

    2015-08-01

    Full Text Available Referring on the development of criminal law recently, it is inevitable to reform the criminal law through changes on the Indonesian Criminal Code (KUHP. Being derived from the foreign law (relic of the colonial era, the Criminal Code has been obsolete, injustice, outmoded and unrealistic irrelevant for the present reality. The type of research employed in this paper is normative research, reviewing the restorative justice principle from the perspective of the criminal law system, with the aim of constructing a restorative justice concept which is ideal to be applied in the Indonesian criminal law system. The concept of restorative justice is an approach of problem solving that emphasizes the recovery of victims and to restore the relationship between the perpetrator and the victim and to their respective communities. By using such approach, the parties are expected to reach a mutual agreement related to the settlement of disputes which expected to harmonize the relationship of the parties prior the occurrence of the crime. On the practical level, the principles on restorative justice for the settlement of criminal case may need to be implemented imminently as part of the criminal system in Indonesia.

  3. Tidal variability of nutrients in a coastal coral reef system influenced by groundwater

    Science.gov (United States)

    Wang, Guizhi; Wang, Shuling; Wang, Zhangyong; Jing, Wenping; Xu, Yi; Zhang, Zhouling; Tan, Ehui; Dai, Minhan

    2018-02-01

    To investigate variation in nitrite, nitrate, phosphate, and silicate in a spring-neap tide in a coral reef system influenced by groundwater discharge, we carried out a time-series observation of these nutrients and 228Ra, a tracer of groundwater discharge, in the Luhuitou fringing reef at Sanya Bay in the South China Sea. The maximum 228Ra, 45.3 dpm 100 L-1, appeared at low tide and the minimum, 14.0 dpm 100 L-1, appeared during a flood tide in the spring tide. The activity of 228Ra was significantly correlated with water depth and salinity in the spring-neap tide, reflecting the tidal-pumping feature of groundwater discharge. Concentrations of all nutrients exhibited strong diurnal variation, with a maximum in the amplitude of the diel change for nitrite, nitrate, phosphate, and silicate in the spring tide of 0.46, 1.54, 0.12, and 2.68 µM, respectively. Nitrate and phosphate were negatively correlated with water depth during the spring tide but showed no correlation during the neap tide. Nitrite was positively correlated with water depth in the spring and neap tide due to mixing of nitrite-depleted groundwater and nitrite-rich offshore seawater. They were also significantly correlated with salinity (R2 ≥ 0.9 and P reef system was closely related with biological processes during both tidal periods, but the biological influence appeared to be less dominant, as inferred from the less significant correlations (R2 = 0.16) during the spring tide when groundwater discharge was more prominent. Thus, the variability of nutrients in the coral reef system was regulated mainly by biological uptake and release in a spring-neap tide and impacted by mixing of tidally driven groundwater and offshore seawater during spring tide.

  4. Groundwater flow systems in the great Aletsch glacier region (Valais, Switzerland)

    Science.gov (United States)

    Alpiger, Andrea; Loew, Simon

    2014-05-01

    Groundwater flow systems in Alpine areas are often complex and challenging to investigate due to special topographic and climatic conditions governing groundwater recharge and bedrock flow. Studies seeking to characterize high-alpine groundwater systems remain rare, but are of high interest, e.g. for water supply, hydropower systems, traffic tunnels or rock slope deformation and landslide hazards. The goal of this study is to better understand the current and past groundwater flow systems of the UNESCO World Heritage mountain ridge separating the great Aletsch glacier and the Rhone valley, considering climatic and glacier fluctuations during the Lateglacial and Holocene periods. This ridge is crossed by a hydropower bypass drift (Riederhornstollen) and is composed of fractured crystalline rocks overlain by various types of landslides and glacial deposits. Surface hydrology observations (fracture properties, groundwater seepage, spring lines and physico-chemical parameters) and hydropower drift inflow measurements contributed to the characterization of bedrock hydraulic conductivities and preferential groundwater pathways. Basic conceptual hydrogeological models were tested with observed drift inflows and the occurrence of springs using free-surface, variably saturated, vertical 2D groundwater flow models (using the code SEEP/W from GeoStudio 2007). Already simple two-layer models, representing profile sections orthogonal to the mountain ridge, provided useful results. Simulations show that differences in the occurrence of springs on each side of the mountain ridge are likely caused by the occurrence of glacial till (generating perched groundwater), the deep-seated sagging landslide mass, faults and asymmetric ridge topography, which together force the main groundwater flow direction to be oriented towards the Rhone valley, even from beyond the mountain ridge. Surprisingly, the most important springs (those with high discharge rates) are located at high elevations

  5. Applying a System Dynamics Approach for Modeling Groundwater Dynamics to Depletion under Different Economical and Climate Change Scenarios

    Directory of Open Access Journals (Sweden)

    Hamid Balali

    2015-09-01

    Full Text Available In the recent decades, due to many different factors, including climate change effects towards be warming and lower precipitation, as well as some structural policies such as more intensive harvesting of groundwater and low price of irrigation water, the level of groundwater has decreased in most plains of Iran. The objective of this study is to model groundwater dynamics to depletion under different economic policies and climate change by using a system dynamics approach. For this purpose a dynamic hydro-economic model which simultaneously simulates the farmer’s economic behavior, groundwater aquifer dynamics, studied area climatology factors and government economical policies related to groundwater, is developed using STELLA 10.0.6. The vulnerability of groundwater balance is forecasted under three scenarios of climate including the Dry, Nor and Wet and also, different scenarios of irrigation water and energy pricing policies. Results show that implementation of some economic policies on irrigation water and energy pricing can significantly affect on groundwater exploitation and its volume balance. By increasing of irrigation water price along with energy price, exploitation of groundwater will improve, in so far as in scenarios S15 and S16, studied area’s aquifer groundwater balance is positive at the end of planning horizon, even in Dry condition of precipitation. Also, results indicate that climate change can affect groundwater recharge. It can generally be expected that increases in precipitation would produce greater aquifer recharge rates.

  6. Response of the groundwater system in the Guanzhong Basin (central China) to climate change and human activities

    Science.gov (United States)

    Wang, Wenke; Zhang, Zaiyong; Duan, Lei; Wang, Zhoufeng; Zhao, Yaqian; Zhang, Qian; Dai, Meiling; Liu, Huizhong; Zheng, Xiaoyan; Sun, Yibo

    2018-03-01

    The Guanzhong Basin in central China features a booming economy and has suffered severe drought, resulting in serious groundwater depletion in the last 30 years. As a major water resource, groundwater plays a significant role in water supply. The combined impact of climate change and intensive human activities has caused a substantial decline in groundwater recharge and groundwater levels, as well as degradation of groundwater quality and associated changes in the ecosystems. Based on observational data, an integrated approach was used to assess the impact of climate change and human activities on the groundwater system and the base flow of the river basin. Methods included: river runoff records and a multivariate statistical analysis of data including historical groundwater levels and climate; hydro-chemical investigation and trend analysis of the historical hydro-chemical data; wavelet analysis of climate data; and the base flow index. The analyses indicate a clear warming trend and a decreasing trend in rainfall since the 1960s, in addition to increased human activities since the 1970s. The reduction of groundwater recharge in the past 30 years has led to a continuous depletion of groundwater levels, complex changes of the hydro-chemical environment, localized salinization, and a strong decline of the base flow to the river. It is expected that the results will contribute to a more comprehensive management plan for groundwater and the related eco-environment in the face of growing pressures from intensive human activities superimposed on climate change in this region.

  7. Hydrochemical characterization and pollution sources identification of groundwater in Salawusu aquifer system of Ordos Basin, China.

    Science.gov (United States)

    Yang, Qingchun; Wang, Luchen; Ma, Hongyun; Yu, Kun; Martín, Jordi Delgado

    2016-09-01

    Ordos Basin is located in an arid and semi-arid region of northwestern China, which is the most important energy source bases in China. Salawusu Formation (Q3 s) is one of the most important aquifer systems of Ordos Basin, which is adjacent to Jurassic coalfield areas. A large-scale exploitation of Jurassic coal resources over ten years results in series of influences to the coal minerals, such as exposed to the oxidation process and dissolution into the groundwater due to the precipitation infiltration. Therefore, how these processes impact groundwater quality is of great concerns. In this paper, the descriptive statistical method, Piper trilinear diagram, ratios of major ions and canonical correspondence analysis are employed to investigate the hydrochemical evolution, determine the possible sources of pollution processes, and assess the controls on groundwater compositions using the monitored data in 2004 and 2014 (before and after large-scale coal mining). Results showed that long-term exploration of coal resources do not result in serious groundwater pollution. The hydrochemical types changed from HCO3(-)-CO3(2-) facies to SO4(2-)-Cl facies during 10 years. Groundwater hardness, nitrate and sulfate pollution were identified in 2014, which was most likely caused by agricultural activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. System Safety Program Plan for Project W-314, tank farm restoration and safe operations

    International Nuclear Information System (INIS)

    Boos, K.A.

    1996-01-01

    This System Safety Program Plan (SSPP) outlines the safety analysis strategy for project W-314, ''Tank Farm Restoration and Safe Operations.'' Project W-314 will provide capital improvements to Hanford's existing Tank Farm facilities, with particular emphasis on infrastructure systems supporting safe operation of the double-shell activities related to the project's conceptual Design Phase, but is planned to be updated and maintained as a ''living document'' throughout the life of the project to reflect the current safety analysis planning for the Tank Farm Restoration and Safe Operations upgrades. This approved W-314 SSPP provides the basis for preparation/approval of all safety analysis documentation needed to support the project

  9. Contribution of the multi-attribute value theory to conflict resolution in groundwater management - application to the Mancha Oriental groundwater system, Spain

    Science.gov (United States)

    Apperl, B.; Pulido-Velazquez, M.; Andreu, J.; Karjalainen, T. P.

    2015-03-01

    The implementation of the EU Water Framework Directive demands participatory water resource management approaches. Decision making in groundwater quantity and quality management is complex because of the existence of many independent actors, heterogeneous stakeholder interests, multiple objectives, different potential policies, and uncertain outcomes. Conflicting stakeholder interests have often been identified as an impediment to the realisation and success of water regulations and policies. The management of complex groundwater systems requires the clarification of stakeholders' positions (identifying stakeholder preferences and values), improving transparency with respect to outcomes of alternatives, and moving the discussion from the selection of alternatives towards the definition of fundamental objectives (value-thinking approach), which facilitates negotiation. The aims of the study are to analyse the potential of the multi-attribute value theory for conflict resolution in groundwater management and to evaluate the benefit of stakeholder incorporation into the different stages of the planning process, to find an overall satisfying solution for groundwater management. The research was conducted in the Mancha Oriental groundwater system (Spain), subject to intensive use of groundwater for irrigation. A complex set of objectives and attributes was defined, and the management alternatives were created by a combination of different fundamental actions, considering different implementation stages and future changes in water resource availability. Interviews were conducted with representative stakeholder groups using an interactive platform, showing simultaneously the consequences of changes in preferences to the alternative ranking. Results show that the approval of alternatives depends strongly on the combination of measures and the implementation stages. Uncertainties in the results were notable, but did not influence the alternative ranking heavily. The

  10. Contribution of the Multi Attribute Value Theory to conflict resolution in groundwater management. Application to the Mancha Oriental groundwater system, Spain

    Science.gov (United States)

    Apperl, B.; Andreu, J.; Karjalainen, T. P.; Pulido-Velazquez, M.

    2014-09-01

    The implementation of the EU Water Framework Directive demands participatory water resource management approaches. Decision making in groundwater quantity and quality management is complex because of the existence of many independent actors, heterogeneous stakeholder interests, multiple objectives, different potential policies, and uncertain outcomes. Conflicting stakeholder interests have been often identified as an impediment to the realization and success of water regulations and policies. The management of complex groundwater systems requires clarifying stakeholders' positions (identifying stakeholders preferences and values), improving transparency with respect to outcomes of alternatives, and moving the discussion from the selection of alternatives towards definition of fundamental objectives (value-thinking approach), what facilitates negotiation. The aims of the study are to analyse the potential of the multi attribute value theory for conflict resolution in groundwater management and to evaluate the benefit of stakeholder incorporation in the different stages of the planning process to find an overall satisfying solution for groundwater management. The research was conducted in the Mancha Oriental groundwater system (Spain), subject to an intensive use of groundwater for irrigation. A complex set of objectives and attributes were defined, and the management alternatives were created by a combination of different fundamental actions, considering different implementation stages and future changes in water resources availability. Interviews were conducted with representative stakeholder groups using an interactive platform, showing simultaneously the consequences of changes of preferences to the alternative ranking. Results show that the acceptation of alternatives depends strongly on the combination of measures and the implementation stages. Uncertainties of the results were notable but did not influence heavily on the alternative ranking. The expected

  11. Installation of the multi-packer system for the long-term monitoring of deep groundwater system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Su; Bae, Dae Seok; Kim, Chun Soo; Park, Byung Yoon; Koh, Yong Kweon; Kim, Geon Young [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-05-01

    The groundwater system in the deep geological environment is very important to evaluate the behavior of the radionuclide migration and near-field barrier system. The multi-packer system was installed to derive the long-term change of the groundwater pressure and its quality in the several isolated monitoring zones with depth in the study sites. The monitoring zones were basically determined by the spatial distribution characteristics of the conductive fracture and their hydraulic properties. To recover the natural groundwater condition, the borehole water was purged after completing the installation. From this equipment, the in-situ data will be provided to the radionuclide migration and system development study. 2 refs., 9 figs., 3 tabs. (Author)

  12. Effects of sea-level rise on barrier island groundwater system dynamics: ecohydrological implications

    Science.gov (United States)

    Masterson, John P.; Fienen, Michael N.; Thieler, E. Robert; Gesch, Dean B.; Gutierrez, Benjamin T.; Plant, Nathaniel G.

    2014-01-01

    We used a numerical model to investigate how a barrier island groundwater system responds to increases of up to 60 cm in sea level. We found that a sea-level rise of 20 cm leads to substantial changes in the depth of the water table and the extent and depth of saltwater intrusion, which are key determinants in the establishment, distribution and succession of vegetation assemblages and habitat suitability in barrier islands ecosystems. In our simulations, increases in water-table height in areas with a shallow depth to water (or thin vadose zone) resulted in extensive groundwater inundation of land surface and a thinning of the underlying freshwater lens. We demonstrated the interdependence of the groundwater response to island morphology by evaluating changes at three sites. This interdependence can have a profound effect on ecosystem composition in these fragile coastal landscapes under long-term changing climatic conditions.

  13. Estimation of groundwater recharge in sedimentary rock aquifer systems in the Oti basin of Gushiegu District, Northern Ghana

    Science.gov (United States)

    Afrifa, George Yamoah; Sakyi, Patrick Asamoah; Chegbeleh, Larry Pax

    2017-07-01

    Sustainable development and the management of groundwater resources for optimal socio-economic development constitutes one of the most effective strategies for mitigating the effects of climate change in rural areas where poverty is a critical cause of environmental damage. This research assessed groundwater recharge and its spatial and temporal variations in Gushiegu District in the Northern Region of Ghana, where groundwater is the main source of water supply for most uses. Isotopic data of precipitation and groundwater were used to infer the origin of groundwater and the possible relationship between groundwater and surface water in the partially metamorphosed sedimentary aquifer system in the study area. Though the data do not significantly establish strong relation between groundwater and surface water, the study suggests that groundwater in the area is of meteoric origin. However, the data also indicate significant enrichment of the heavy isotopes (18O and 2H) in groundwater relative to rainwater in the area. The Chloride Mass Balance (CMB) and Water Table Fluctuations (WTF) techniques were used to quantitatively estimate the groundwater recharge in the area. The results suggest groundwater recharge in a range of 13.9 mm/y - 218 mm/y, with an average of 89 mm/yr, representing about 1.4%-21.8% (average 8.9%) of the annual precipitation in the area. There is no clearly defined trend in the temporal variations of groundwater recharge in the area, but the spatial variations are discussed in relation to the underlying lithologies. The results suggest that the fraction of precipitation that reaches the saturated zone as groundwater recharge is largely controlled by the vertical hydraulic conductivities of the material of the unsaturated zone. The vertical hydraulic conductivity coupled with humidity variations in the area modulates the vertical infiltration and percolation of precipitation.

  14. Fast digital zooming system using directionally adaptive image interpolation and restoration.

    Science.gov (United States)

    Kang, Wonseok; Jeon, Jaehwan; Yu, Soohwan; Paik, Joonki

    2014-01-01

    This paper presents a fast digital zooming system for mobile consumer cameras using directionally adaptive image interpolation and restoration methods. The proposed interpolation algorithm performs edge refinement along the initially estimated edge orientation using directionally steerable filters. Either the directionally weighted linear or adaptive cubic-spline interpolation filter is then selectively used according to the refined edge orientation for removing jagged artifacts in the slanted edge region. A novel image restoration algorithm is also presented for removing blurring artifacts caused by the linear or cubic-spline interpolation using the directionally adaptive truncated constrained least squares (TCLS) filter. Both proposed steerable filter-based interpolation and the TCLS-based restoration filters have a finite impulse response (FIR) structure for real time processing in an image signal processing (ISP) chain. Experimental results show that the proposed digital zooming system provides high-quality magnified images with FIR filter-based fast computational structure.

  15. Lockheed Martin Energy Systems, Inc., Groundwater Program Office. Annual report for fiscal year 1994

    International Nuclear Information System (INIS)

    1994-01-01

    This edition of the Lockheed Martin Energy Systems, Inc., (Energy Systems) Groundwater Program Annual Report summarizes the work carried out by the Energy Systems Groundwater Program Office (GWPO) for fiscal year (FY) 1994. The GWPO is responsible for coordination and oversight for all components of the groundwater programs at the three Oak Ridge facilities [Oak Ridge National Laboratory (ORNL), the Oak Ridge Y-12 Plant, and the Oak Ridge K-25 Site], as well as the Paducah and Portsmouth Gaseous Diffusion Plants (PGDP and PORTS, respectively.) This report describes the administrative framework of the GWPO including staffing, organization, and funding sources. In addition, summaries are provided of activities involving the Technical Support staff at the five facilities. Finally, the results of basic investigations designed to improve our understanding of the major processes governing groundwater flow and contaminant migration on the Oak Ridge Reservation (ORR) are reported. These investigations are conducted as part of the Oak Ridge Reservation Hydrology and Geology Studies (ORRHAGS) program. The relevance of these studies to the overall remediation responsibilities of Energy Systems is discussed

  16. Geochemical and Isotopic Interpretations of Groundwater Flow in the Oasis Valley Flow System, Southern Nevada

    International Nuclear Information System (INIS)

    Thomas, J.M.; Benedict, F.C. Jr.; Rose, T.P.; Hershey, R.L.; Paces, J.B.; Peterman, Z.E.; Farnham, I.M.; Johannesson, K.H.; Singh, A.K.; Stetzenbach, K.J.; Hudson, G.B.; Kenneally, J.M.; Eaton, G.F.; Smith, D.K.

    2003-01-01

    This report summarizes the findings of a geochemical investigation of the Pahute Mesa-Oasis Valley groundwater flow system in southwestern Nevada. It is intended to provide geochemical data and interpretations in support of flow and contaminant transport modeling for the Western and Central Pahute Mesa Corrective Action Units

  17. Numerical modeling analysis of VOC removal processes in different aerobic vertical flow systems for groundwater remediation

    NARCIS (Netherlands)

    De Biase, C.; Carminati, A.; Oswald, S.E.; Thullner, M.

    2013-01-01

    Vertical flow systems filled with porous medium have been shown to efficiently remove volatile organic contaminants (VOCs) from contaminated groundwater. To apply this semi-natural remediation strategy it is however necessary to distinguish between removal due to biodegradation and due to volatile

  18. Crime Victims Support System and Restorative Justice: Possible Implementation in Malaysia

    Directory of Open Access Journals (Sweden)

    Azlinda Azman, PhD

    2013-06-01

    Full Text Available Victims’ position is increasingly acknowledged in the criminal justice system across the world. Because of that, criminal justice systems in various countries slowly transform from focusing too much on the relationship between offenders and the legal system and to between the offenders and their victims. Several programs are highlighted such as victim-offender mediation, family group conferences, reparative orders and referral orders in this article. Findings from several studies support the effectiveness of the programs on both the victims and the offenders in terms of several measurements such as satisfaction and recidivism. Looking at this revolution, Malaysian academicians and professionals are beginning to recognize restorative justice as a possible revolution to its criminal justice system, but Malaysian criminal justice system first needs to strengthen or build components that support victims of crime, as this is one of the main principles of restorative justice. Currently, Malaysia still focuses on offenders and their relationship with legal system, but not much with their own victims (physical, emotional, and psychological consequences of the crime. Several possible issues before formal implementation of restorative justice are discussed. The issues (culture, training, and attitude of Malaysian people, including the victims, offenders, and those who work with them can influence the efficiency of restorative justice programs if not identified systematically. These issues can also be the possible research areas to be ventured in the future as these researches can help in implementation.

  19. Genesis and transport of hexavalent chromium in the system ophiolitic rocks - groundwater

    Science.gov (United States)

    Shchegolikhina, Anastasia; Guadagnini, Laura; Guadagnini, Alberto

    2015-04-01

    Our study aims at contributing to the quantification and characterization of chromium transport processes from host rocks and soil matrices to groundwater. We focus on dissolved hexavalent chromium detected in groundwaters of geological regions with ophiolitic rocks (ophiolites and serpentinites) inclusions due to its critical ecological impact. (Oze et al., 2004). Despite the large number of analyses on the occurrence of high concentrations of hazardous hexavalent chromium ions in natural waters, only few studies were performed with the objective of identifying and investigating the geochemical reactions which could occur in the natural system rock - groundwater - dissolved chromium (Fantoni et al., 2002, Stephen and James, 2004, Lelli et al., 2013). In this context, there is a need for integration of results obtained from diverse studies in various regions and settings to improve our knowledge repository. Our theoretical analyses are grounded and driven by practical scenarios detected in subsurface reservoirs exploited for civil and industrial use located in the Emilia-Romagna region (Italy). Available experimental datasets are complemented with data from other international regional-scale settings (Altay mountains region, Russia). Modeling of chromium transformation and migration particularly includes characterization of the multispecies geochemical system. A key aspect of our study is the analysis of the complex competitive sorption processes governing heavy metal evolution in groundwater. The results of the research allow assessing the critical qualitative features of the mechanisms of hexavalent chromium ion mobilization from host rocks and soils and the ensuing transformation and migration to groundwater under the influence of diverse environmental factors. The study is then complemented by the quantification of the main sources of uncertainty associated with prediction of heavy metal contamination levels in the groundwater system explored. Fantoni, D

  20. Intelligent automated control of robotic systems for environmental restoration

    International Nuclear Information System (INIS)

    Harrigan, R.W.

    1992-01-01

    The US Department of Energy's Office of Technology Development (OTD) has sponsored the development of the Generic Intelligent System Controller (GISC) for application to remote system control. Of primary interest to the OTD is the development of technologies which result in faster, safer, and cheaper cleanup of hazardous waste sites than possible using conventional approaches. The objective of the GISC development project is to support these goals by developing a modular robotics control approach which reduces the time and cost of development by allowing reuse of control system software and uses computer models to improve the safety of remote site cleanup while reducing the time and life cycle costs

  1. Evaluation of an integrated treatment system for MGP site groundwaters

    International Nuclear Information System (INIS)

    Scheible, O.K.; Grey, G.M.; Maiello, J.A.

    1995-01-01

    Initially studied at bench scale, process sequences comprising dissolved air flotation (DAF), aerobic biological oxidation, air stripping, filtration, and carbon adsorption were demonstrated at pilot scale at a manufactured gas plant (MGP) site in New Jersey. Benzene, toluene, ethylbenzene, and xylenes (BTEX), and polycyclic aromatic hydrocarbons (PAHs) were the primary organics in the groundwater, ranging from levels of 2 to 8 mg/L and 0.3 to 27 mg/L, respectively; chemical oxygen demand (COD) levels were from 60 to 4,500 mg/L. Significant levels of dense, emulsified, and nonaqueous tars and oils were present in the more highly contaminated waters and were effectively removed by DAF. Carbon-based fluidized-bed biological treatment of the DAF subnatant at COD loadings between 2 and 4 g/L-d yielded effluent-soluble COD levels between 40 and 60 mg/L, with both residual BTEX and PAH concentrations ranging from nondetect levels to 0.1 mg/L. Subsequent polishing by filtration and carbon adsorption resulted in additional COD removal and nondetect levels of volatiles and semivolatiles. Air stripping was effective in lieu of the biological process for both volatile organic compound (VOC) and PAH removal

  2. Characterization of the shallow groundwater system in an alpine watershed: Handcart Gulch, Colorado, USA

    Science.gov (United States)

    Kahn, Katherine G.; Ge, Shemin; Caine, Jonathan S.; Manning, A.

    2008-01-01

    Water-table elevation measurements and aquifer parameter estimates are rare in alpine settings because few wells exist in these environments. Alpine groundwater systems may be a primary source of recharge to regional groundwater flow systems. Handcart Gulch is an alpine watershed in Colorado, USA comprised of highly fractured Proterozoic metamorphic and igneous rocks with wells completed to various depths. Primary study objectives include determining hydrologic properties of shallow bedrock and surficial materials, developing a watershed water budget, and testing the consistency of measured hydrologic properties and water budget by constructing a simple model incorporating groundwater and surface water for water year 2005. Water enters the study area as precipitation and exits as discharge in the trunk stream or potential recharge for the deeper aquifer. Surficial infiltration rates ranged from 0.1-6.2??0-5 m/s. Discharge was estimated at 1.28??10-3 km3. Numerical modeling analysis of single-well aquifer tests predicted lower specific storage in crystalline bedrock than in ferricrete and colluvial material (6.7??10-5-2.10??0-3 l/m). Hydraulic conductivity in crystalline bedrock was significantly lower than in colluvial and alluvial material (4.3??10-9 -2.0??10-4 m/s). Water budget results suggest that during normal precipitation and temperatures water is available to recharge the deeper groundwater flow system. ?? Springer-Verlag 2007.

  3. Implementing the Prepaid Smart Meter System for Irrigated Groundwater Production in Northern China: Status and Problems

    Directory of Open Access Journals (Sweden)

    Xiaowei Wang

    2017-05-01

    Full Text Available To reduce the gap between groundwater demand and supply caused by agricultural groundwater over-exploitation, the Prepaid Smart Meter System (PSMS is being strongly implemented by the Chinese government in northern China. This study reports the analysis and results of PSMS field surveys in six typical provinces in northern China as well as domestic literature reviews. Based on the architecture and implementation policies of the system, the implementation differences between areas and the influencing factors were analyzed, particularly the acknowledgment of farmers, the installation proportion of tube wells, the social benefits. Great achievements have been gained in the implementation, and the management targets have been achieved, including accurately metering overall irrigation groundwater production, assisting in the total amount control and quota management, reducing groundwater exploitation, and improving water use efficiency. However, shortcomings remain in the implementation process, such as single initial investment channels, imperfect policy system construction, a lack of retrieving and analyzing data, and the unbalanced development between areas. Countermeasures and suggestions for these problems are discussed in this article.

  4. Intelligent automated control of robotic systems for environmental restoration

    International Nuclear Information System (INIS)

    Harrigan, R.W.

    1992-01-01

    Remote systems are needed to accomplish many tasks, such as the cleanup of waste sites in which the exposure of personnel to radiation, chemical, explosive, and other hazardous constituents is unacceptable. In addition, hazardous operations, which in the past have been completed by technicians, are under scrutiny because of the high costs and low productivity associated with providing protective clothing and environments. Traditional remote operations have, unfortunately, proven to also have very low productivity when compared with unencumbered human operators. However, recent advances in the integration of sensors and computing into the control of remotely operated equipment has shown great promise for reducing the cost of remote systems by providing faster and safer remote systems. The US Department of Energy's Office of Technology Development (OTD) has sponsored the development of the generic intelligent system controller (GISC) for application to remote system control. The GISC employs a highly modular architecture employing distributed real-time computing resources for speed and efficiency of computation. Currently, the graphics interface of GISC has been implemented on a Unix-based Silicon Graphics computer using commercial animation graphics software modified for real-time updating from sensory systems. A first implementation of GISC has been completed and is currently in use at Hanford, Washington, as part of the underground storage tank robotics technology development program

  5. Modeling Groundwater Flow System of a Drainage Basin in the Basement Complex Environment of Southwestern Nigera

    Science.gov (United States)

    Akinwumiju, Akinola S.; Olorunfemi, Martins O.

    2018-05-01

    This study attempted to model the groundwater flow system of a drainage basin within the Basement Complex environment of Southwestern Nigeria. Four groundwater models were derived from Vertical Electrical Sounding (VES) Data, remotely sensed data, geological information (hydrolineaments and lithology) and borehole data. Subsequently, two sub-surface (local and regional) flow systems were delineated in the study area. While the local flow system is controlled by surface topography, the regional flow system is controlled by the networks of intermediate and deep seated faults/fractures. The local flow system is characterized by convergence, divergence, inflow and outflow in places, while the regional flow system is dominated by NNE-SSW and W-E flow directions. Minor flow directions include NNW-SSE and E-W with possible linkages to the main flow-paths. The NNE-SSW regional flow system is a double open ended flow system with possible linkage to the Niger Trough. The W-E regional flow system is a single open ended system that originates within the study area (with possible linkage to the NNE-SSW regional flow system) and extends to Ikogosi in the adjoining drainage basin. Thus, the groundwater drainage basin of the study area is much larger and extensive than its surface drainage basin. The all year round flowing (perennial) rivers are linked to groundwater outcrops from faults/fractures and contact zones. Consequently, larger percentage of annual rainwater usually leaves the basin in form of runoff and base flow. Therefore, the basin is categorized as a donor basin but with suspected subsurface water input at its northeastern axis.

  6. Numerical modeling of groundwater flow in the coastal aquifer system of Taranto (southern Italy)

    Science.gov (United States)

    De Filippis, Giovanna; Giudici, Mauro; Negri, Sergio; Margiotta, Stefano; Cattaneo, Laura; Vassena, Chiara

    2014-05-01

    The Mediterranean region is characterized by a strong development of coastal areas with a high concentration of water-demanding human activities, resulting in weakly controlled withdrawals of groundwater which accentuate the saltwater intrusion phenomenon. The worsening of groundwater quality is a huge problem especially for those regions, like Salento (southern Italy), where a karst aquifer system represents the most important water resource because of the deficiency of a well developed superficial water supply. In this frame, the first 2D numerical model describing the groundwater flow in the karst aquifer of Salento peninsula was developed by Giudici et al. [1] at the regional scale and then improved by De Filippis et al. [2]. In particular, the estimate of the saturated thickness of the deep aquifer highlighted that the Taranto area is particularly sensitive to the phenomenon of seawater intrusion, both for the specific hydrostratigraphic configuration and for the presence of highly water-demanding industrial activities. These remarks motivate a research project which is part of the research program RITMARE (The Italian Research for the Sea), within which a subprogram is specifically dedicated to the problem of the protection and preservation of groundwater quality in Italian coastal aquifers and in particular, among the others, in the Taranto area. In this context, the CINFAI operative unit aims at providing a contribution to the characterization of groundwater in the study area. The specific objectives are: a. the reconstruction of the groundwater dynamic (i.e., the preliminary identification of a conceptual model for the aquifer system and the subsequent modeling of groundwater flow in a multilayered system which is very complex from the hydrostratigraphical point of view); b. the characterization of groundwater outflows through submarine and subaerial springs and the water exchanges with the shallow coastal water bodies (e.g. Mar Piccolo) and the off

  7. Groundwater flow system stability in shield settings a multi-disciplinary approach

    International Nuclear Information System (INIS)

    Jensen, M.R.; Goodwin, B.W.

    2004-01-01

    Within the Deep Geologic Repository Technology Program (DGRTP) several Geoscience activities are focused on advancing the understanding of groundwater flow system evolution and geochemical stability in a Shield setting as affected by long-term climate change. A key aspect is developing confidence in predictions of groundwater flow patterns and residence times as they relate to the safety of a Deep Geologic Repository for used nuclear fuel waste. A specific focus in this regard has been placed on constraining redox stability and groundwater flow system dynamics during the Pleistocene. Attempts are being made to achieve this through a coordinated multi-disciplinary approach intent on; i) demonstrating coincidence between independent geo-scientific data; ii) improving the traceability of geo-scientific data and its interpretation within a conceptual descriptive model(s); iii) improving upon methods to assess and demonstrate robustness in flow domain prediction(s) given inherent flow domain uncertainties (i.e. spatial chemical/physical property distributions; boundary conditions) in time and space; and iv) improving awareness amongst geo-scientists as to the utility various geo-scientific data in supporting a repository safety case. Coordinated by the DGRTP, elements of this program include the development of a climate driven Laurentide ice-sheet model to constrain the understanding of time rate of change in boundary conditions most affecting the groundwater flow domain and its evolution. Further work has involved supporting WRA Paleo-hydrogeologic studies in which constrained thermodynamic analyses coupled with field studies to characterize the paragenesis of fracture infill mineralogy are providing evidence to premise understandings of possible depth of penetration by oxygenated glacial recharge. In parallel. numerical simulations have been undertaken to illustrate aspect of groundwater flow system stability and evolution in a Shield setting. Such simulations

  8. Construction and calibration of a groundwater-flow model to assess groundwater availability in the uppermost principal aquifer systems of the Williston Basin, United States and Canada

    Science.gov (United States)

    Davis, Kyle W.; Long, Andrew J.

    2018-05-31

    The U.S. Geological Survey developed a groundwater-flow model for the uppermost principal aquifer systems in the Williston Basin in parts of Montana, North Dakota, and South Dakota in the United States and parts of Manitoba and Saskatchewan in Canada as part of a detailed assessment of the groundwater availability in the area. The assessment was done because of the potential for increased demands and stresses on groundwater associated with large-scale energy development in the area. As part of this assessment, a three-dimensional groundwater-flow model was developed as a tool that can be used to simulate how the groundwater-flow system responds to changes in hydrologic stresses at a regional scale.The three-dimensional groundwater-flow model was developed using the U.S. Geological Survey’s numerical finite-difference groundwater model with the Newton-Rhapson solver, MODFLOW–NWT, to represent the glacial, lower Tertiary, and Upper Cretaceous aquifer systems for steady-state (mean) hydrological conditions for 1981‒2005 and for transient (temporally varying) conditions using a combination of a steady-state period for pre-1960 and transient periods for 1961‒2005. The numerical model framework was constructed based on existing and interpreted hydrogeologic and geospatial data and consisted of eight layers. Two layers were used to represent the glacial aquifer system in the model; layer 1 represented the upper one-half and layer 2 represented the lower one-half of the glacial aquifer system. Three layers were used to represent the lower Tertiary aquifer system in the model; layer 3 represented the upper Fort Union aquifer, layer 4 represented the middle Fort Union hydrogeologic unit, and layer 5 represented the lower Fort Union aquifer. Three layers were used to represent the Upper Cretaceous aquifer system in the model; layer 6 represented the upper Hell Creek hydrogeologic unit, layer 7 represented the lower Hell Creek aquifer, and layer 8 represented the Fox

  9. Autonomic nervous system function in chronic exogenous subclinical thyrotoxicosis and the effect of restoring euthyroidism

    NARCIS (Netherlands)

    Eustatia-Rutten, Carmen F. A.; Corssmit, Eleonora P. M.; Heemstra, Karen A.; Smit, Johannes W. A.; Schoemaker, Rik C.; Romijn, Johannes A.; Burggraaf, Jacobus

    2008-01-01

    Knowledge on the relationship between the autonomic nervous system and subclinical hyperthyroidism is mainly based upon cross-sectional studies in heterogeneous patient populations, and the effect of restoration to euthyroidism in subclinical hyperthyroidism has not been studied. We investigated the

  10. Human virus and microbial indicator occurrence in public-supply groundwater systems: meta-analysis of 12 international studies

    Science.gov (United States)

    Groundwater quality is often evaluated using microbial indicators. This study examines data from 12 international groundwater studies (conducted 1992–2013). Sites were chosen from 718 public drinking-water systems with a range of hydrogeological conditions. Focus was on testing the value of indicato...

  11. Using SWAT-MODFLOW to simulate groundwater flow and groundwater-surface water interactions in an intensively irrigated stream-aquifer system

    Science.gov (United States)

    Wei, X.; Bailey, R. T.

    2017-12-01

    Agricultural irrigated watersheds in semi-arid regions face challenges such as waterlogging, high soil salinity, reduced crop yield, and leaching of chemical species due to extreme shallow water tables resulting from long-term intensive irrigation. Hydrologic models can be used to evaluate the impact of land management practices on water yields and groundwater-surface water interactions in such regions. In this study, the newly developed SWAT-MODFLOW, a coupled surface/subsurface hydrologic model, is applied to a 950 km2 watershed in the Lower Arkansas River Valley (southeastern Colorado). The model accounts for the influence of canal diversions, irrigation applications, groundwater pumping, and earth canal seepage losses. The model provides a detailed description of surface and subsurface flow processes, thereby enabling detailed description of watershed processes such as runoff, infiltration, in-streamflow, three-dimensional groundwater flow in a heterogeneous aquifer system with sources and sinks (e.g. pumping, seepage to subsurface drains), and spatially-variable surface and groundwater exchange. The model was calibrated and tested against stream discharge from 5 stream gauges in the Arkansas River and its tributaries, groundwater levels from 70 observation wells, and evapotranspiration (ET) data estimated from satellite (ReSET) data during the 1999 to 2007 period. Since the water-use patterns within the study area are typical of many other irrigated river valleys in the United States and elsewhere, this modeling approach is transferable to other regions.

  12. Improved aquifer characterization and the optimization of the design of brackish groundwater desalination systems

    KAUST Repository

    Malivaa, Robert G.

    2011-07-01

    Many water scarce regions possess brackish-water resources that can be desalted to provide alternative water supplies. Brackish groundwater desalination by reverse osmosis (RO) is less expensive than seawater systems because of reduced energy and pretreatment requirements and lesser volumes of concentrate that require disposal. Development of brackish groundwater wellfields include the same hydraulic issues that affect conventional freshwater wellfields. Managing well interference and prevention of adverse impacts such as land subsidence are important concerns. RO systems are designed to treat water whose composition falls within a system-specific envelope of salinities and ion concentrations. A fundamental requirement for the design of brackish groundwater RO systems is prediction of the produced water chemistry at both the start of pumping and after 10-20 years of operation. Density-dependent solute-transport modeling is thus an integral component of the design of brackish groundwater RO systems. The accuracy of groundwater models is dependent upon the quality of the hydrogeological data upon which they are based. Key elements of the aquifer characterization are the determination of the three-dimensional distribution of salinity within the aquifer and the evaluation of aquifer heterogeneity with respect to hydraulic conductivity. It is necessary to know from where in a pumped aquifer (or aquifer zone) water is being produced and the contribution of vertical flow to the produced water. Unexpected, excessive vertical migration (up-coning) of waters that are more saline has adversely impacted some RO systems because the salinity of the water delivered to the system exceeded the system design parameters. Improved aquifer characterization is possible using advanced geophysical techniques, which can, in turn, lead to more accurate solute-transport models. Advanced borehole geophysical logs, such as nuclear magnetic resonance, were run as part of the exploratory test

  13. Screening of sustainable groundwater sources for integration into a regional drought-prone water supply system

    Directory of Open Access Journals (Sweden)

    H. Lucas

    2009-07-01

    Full Text Available This paper reports on the qualitative and quantitative screening of groundwater sources for integration into the public water supply system of the Algarve, Portugal. The results are employed in a decision support system currently under development for an integrated water resources management scheme in the region. Such a scheme is crucial for several reasons, including the extreme seasonal and annual variations in rainfall, the effect of climate change on more frequent and long-lasting droughts, the continuously increasing water demand and the high risk of a single-source water supply policy. The latter was revealed during the severe drought of 2004 and 2005, when surface reservoirs were depleted and the regional water demand could not be met, despite the drilling of emergency wells.

    For screening and selection, quantitative criteria are based on aquifer properties and well yields, whereas qualitative criteria are defined by water quality indices. These reflect the well's degree of violation of drinking water standards for different sets of variables, including toxicity parameters, nitrate and chloride, iron and manganese and microbiological parameters. Results indicate the current availability of at least 1100 l s−1 of high quality groundwater (55% of the regional demand, requiring only disinfection (900 l s−1 or basic treatment, prior to human consumption. These groundwater withdrawals are sustainable when compared to mean annual recharge, considering that at least 40% is preserved for ecological demands. A more accurate and comprehensive analysis of sustainability is performed with the help of steady-state and transient groundwater flow simulations, which account for aquifer geometry, boundary conditions, recharge and discharge rates, pumping activity and seasonality. They permit an advanced analysis of present and future scenarios and show that increasing water demands and decreasing rainfall will make

  14. Simulation of groundwater flow in the glacial aquifer system of northeastern Wisconsin with variable model complexity

    Science.gov (United States)

    Juckem, Paul F.; Clark, Brian R.; Feinstein, Daniel T.

    2017-05-04

    The U.S. Geological Survey, National Water-Quality Assessment seeks to map estimated intrinsic susceptibility of the glacial aquifer system of the conterminous United States. Improved understanding of the hydrogeologic characteristics that explain spatial patterns of intrinsic susceptibility, commonly inferred from estimates of groundwater age distributions, is sought so that methods used for the estimation process are properly equipped. An important step beyond identifying relevant hydrogeologic datasets, such as glacial geology maps, is to evaluate how incorporation of these resources into process-based models using differing levels of detail could affect resulting simulations of groundwater age distributions and, thus, estimates of intrinsic susceptibility.This report describes the construction and calibration of three groundwater-flow models of northeastern Wisconsin that were developed with differing levels of complexity to provide a framework for subsequent evaluations of the effects of process-based model complexity on estimations of groundwater age distributions for withdrawal wells and streams. Preliminary assessments, which focused on the effects of model complexity on simulated water levels and base flows in the glacial aquifer system, illustrate that simulation of vertical gradients using multiple model layers improves simulated heads more in low-permeability units than in high-permeability units. Moreover, simulation of heterogeneous hydraulic conductivity fields in coarse-grained and some fine-grained glacial materials produced a larger improvement in simulated water levels in the glacial aquifer system compared with simulation of uniform hydraulic conductivity within zones. The relation between base flows and model complexity was less clear; however, the relation generally seemed to follow a similar pattern as water levels. Although increased model complexity resulted in improved calibrations, future application of the models using simulated particle

  15. 5-year clinical performance of resin composite versus resin modified glass ionomer restorative system in non-carious cervical lesions

    DEFF Research Database (Denmark)

    Franco, Eduardo Batista; Benetti, Ana Raquel; Ishikiriama, Sérgio Kiyoshi

    2006-01-01

    To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions.......To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions....

  16. Review of passive groundwater remediation systems: Lessons learned Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1997-08-01

    One of the proposed solutions for treatment of the contaminated groundwater in the Bear Creek Valley is the installation of a passive treatment system. Such a system would use a reactive media installed in a continuous trench or in a gate as part of a barrier wall and gate system. This report evaluates information on five similar systems [no information was available on two additional systems] and evaluates the shortcomings and the advantages of each. Section 5 provides a short summary of the findings and presents some recommendations on how to avoid some of the common problems encountered with the existing systems

  17. Effects of climate change on groundwater: observed and forecasted trends on Italian systems

    Science.gov (United States)

    Doveri, Marco; Menichini, Matia; Provenzale, Antonello; Scozzari, Andrea

    2017-04-01

    Groundwater represents the main source of water supply at global level. In Italy, as well as in most European countries, water needs are mainly covered by groundwater exploitation. The reliance on this resource is continuously growing, given the key role that groundwater plays for mitigating the climate change/variability and for addressing the significant increase in the global water demand. Despite this, and unlike surface waters, groundwater bodies have not been widely studied, and there is a general paucity of quantitative information, especially in relation to climate change. Although groundwater systems are more resilient to climate change than surface waters, they are affected both directly and indirectly. The estimation of the entity of these effects is mandatory for a reliable management of this crucial resource. The analysis of hydro-meteorological data over a few decades highlights that also the Italian territory is experiencing a change of the climate regime. Besides the increase of mean annual temperature, observed in particular since the early 1980s, longer and more frequent drought periods have been registered, as well as an increase of extreme events characterized by heavy rainfall. It is also noticeable a decrease in total rainfall, that is much more evident in the period from January to June. In addition to the reduced yearly inputs from precipitation, such trends determine also a lower snow accumulation and earlier snow melt in mountain areas, a general increase of evapotranspiration rates and an increased runoff fraction of the effective rainfall amount. As flood hydrographs of several major Italian rivers (e.g., Po, Brenta and Arno rivers) confirm, evident effects concern surface water resources. The main observed phenomena consist in the decline of mean annual discharge, the increase of extreme events with high discharge concentrated in short periods, and longer and earlier periods of low base flow. Impacts on groundwater recharge are not well

  18. The installation of a multiport ground-water sampling system in the 300 Area

    International Nuclear Information System (INIS)

    Gilmore, T.J.

    1989-06-01

    In 1988, the Pacific Northwest Laboratory installed a multiport groundwater sampling system in well 399-1-20, drilled north of the 300 Area on the Hanford Site in southwestern Washington State. The purpose of installing the multiport system is to evaluate methods of determining the vertical distribution of contaminants and hydraulic heads in ground water. Well 399-1-20 is adjacent to a cluster of four Resource Conservation and Recovery Act (RCRA) ground-water monitoring wells. This proximity makes it possible to compare sampling intervals and head measurements between the multiport system and the RCRA monitoring wells. Drilling and installation of the multiport system took 42 working days. Six sampling ports were installed in the upper unconfined aquifer at depths of approximately 120, 103, 86, 74, 56, and 44 feet. The locations of the sampling ports were determined by the hydrogeology of the area and the screened intervals of adjacent ground-water monitoring wells. The system was installed by backfilling sand around the sampling ports and isolating the ports with bentonite seals. The method proved adequate. For future installation, however, development and evaluation of an alternative method is recommended. In the alternative method suggested, the multiport system would be placed inside a cased and screened well, using packers to isolate the sampling zones. 4 refs., 8 figs., 1 tab

  19. Groundwater discharge and phosphorus dynamics in a flood-pulse system: Tonle Sap Lake, Cambodia

    Science.gov (United States)

    Burnett, William C.; Wattayakorn, Gullaya; Supcharoen, Ratsirin; Sioudom, Khamfeuane; Kum, Veasna; Chanyotha, Supitcha; Kritsananuwat, Rawiwan

    2017-06-01

    Tonle Sap Lake (Cambodia), a classic example of a "flood pulse" system, is the largest freshwater lake in SE Asia, and is reported to have one of the highest freshwater fish productions anywhere. During the dry season (November-April) the lake drains through a tributary to the Mekong River. The flow in the connecting tributary completely reverses during the wet monsoon (May-October), adding huge volumes of water back to the lake, increasing its area about six fold. The lake is likely phosphorus limited and we hypothesized that groundwater discharge, including recirculated lake water, may represent an important source of P and other nutrients. To address this question, we surveyed hundreds of kilometers of the lake for natural 222Rn (radon), temperature, conductivity, GPS coordinates and water depth. All major inorganic nutrients and phosphorus species were evaluated by systematic sampling throughout the lake. Results showed that there were radon hotspots, all at the boundaries between the permanent lake and the floodplain, indicating likely groundwater inputs. A radon mass balance model indicates that the groundwater flow to Tonle Sap Lake is approximately 10 km3/yr, about 25% as large as the floodwaters entering from the Mekong River during the wet monsoon. Our results suggest that the groundwater-derived dissolved inorganic phosphorus (DIP) contribution to Tonle Sap is more than 30% of the average inflows from all natural sources. Since the productivity of the lake appears to be phosphorus limited, this finding suggests that the role of groundwater is significant for Tonle Sap Lake and perhaps for other flood pulse systems worldwide.

  20. Multivariate analysis of the heterogeneous geochemical processes controlling arsenic enrichment in a shallow groundwater system.

    Science.gov (United States)

    Huang, Shuangbing; Liu, Changrong; Wang, Yanxin; Zhan, Hongbin

    2014-01-01

    The effects of various geochemical processes on arsenic enrichment in a high-arsenic aquifer at Jianghan Plain in Central China were investigated using multivariate models developed from combined adaptive neuro-fuzzy inference system (ANFIS) and multiple linear regression (MLR). The results indicated that the optimum variable group for the AFNIS model consisted of bicarbonate, ammonium, phosphorus, iron, manganese, fluorescence index, pH, and siderite saturation. These data suggest that reductive dissolution of iron/manganese oxides, phosphate-competitive adsorption, pH-dependent desorption, and siderite precipitation could integrally affect arsenic concentration. Analysis of the MLR models indicated that reductive dissolution of iron(III) was primarily responsible for arsenic mobilization in groundwaters with low arsenic concentration. By contrast, for groundwaters with high arsenic concentration (i.e., > 170 μg/L), reductive dissolution of iron oxides approached a dynamic equilibrium. The desorption effects from phosphate-competitive adsorption and the increase in pH exhibited arsenic enrichment superior to that caused by iron(III) reductive dissolution as the groundwater chemistry evolved. The inhibition effect of siderite precipitation on arsenic mobilization was expected to exist in groundwater that was highly saturated with siderite. The results suggest an evolutionary dominance of specific geochemical process over other factors controlling arsenic concentration, which presented a heterogeneous distribution in aquifers. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of Environmental Science and Health, Part A, to view the supplemental file.

  1. Quantifying the energy required for groundwater pumping across a regional aquifer system

    Science.gov (United States)

    Ronayne, M. J.; Shugert, D. T.

    2017-12-01

    Groundwater pumping can be a substantial source of energy expenditure, particularly in semiarid regions with large depths to water. In this study we assessed the energy required for groundwater pumping in the Denver Basin aquifer system, a group of sedimentary rock aquifers used for municipal water supply in Colorado. In recent decades, declining water levels in the Denver Basin aquifers has resulted in increased pumping lifts and higher energy use rates. We quantified the spatially variable energy intensity for groundwater pumping by analyzing spatial variations in the lift requirement. The median energy intensities for two major aquifers were 1.2 and 1.8 kWh m-3. Considering typical municipal well production rates and household water use in the study area, these results indicate that the energy cost associated with groundwater pumping can be a significant fraction (>20%) of the total electricity consumption for all household end uses. Pumping at this scale (hundreds of municipal wells producing from deep aquifers) also generates substantial greenhouse gas emissions. Analytical wellfield modeling conducted as part of this study clearly demonstrates how multiple components of the lift impact the energy requirement. Results provide guidance for water management strategies that reduce energy expenditure.

  2. Shells, orbit bifurcations, and symmetry restorations in Fermi systems

    Energy Technology Data Exchange (ETDEWEB)

    Magner, A. G., E-mail: magner@kinr.kiev.ua; Koliesnik, M. V. [NASU, Institute for Nuclear Research (Ukraine); Arita, K. [Nagoya Institute of Technology, Department of Physics (Japan)

    2016-11-15

    The periodic-orbit theory based on the improved stationary-phase method within the phase-space path integral approach is presented for the semiclassical description of the nuclear shell structure, concerning themain topics of the fruitful activity ofV.G. Soloviev. We apply this theory to study bifurcations and symmetry breaking phenomena in a radial power-law potential which is close to the realistic Woods–Saxon one up to about the Fermi energy. Using the realistic parametrization of nuclear shapes we explain the origin of the double-humped fission barrier and the asymmetry in the fission isomer shapes by the bifurcations of periodic orbits. The semiclassical origin of the oblate–prolate shape asymmetry and tetrahedral shapes is also suggested within the improved periodic-orbit approach. The enhancement of shell structures at some surface diffuseness and deformation parameters of such shapes are explained by existence of the simple local bifurcations and new non-local bridge-orbit bifurcations in integrable and partially integrable Fermi-systems. We obtained good agreement between the semiclassical and quantum shell-structure components of the level density and energy for several surface diffuseness and deformation parameters of the potentials, including their symmetry breaking and bifurcation values.

  3. The Space for Restorative Justice in the Ethiopian Criminal Justice System

    Directory of Open Access Journals (Sweden)

    Endalew Lijalem Enyew

    2014-12-01

    Full Text Available Restorative Justice (RJ is an alternative way of apprehending crime and justice which views crime as a violation of a relationship among victims, offenders and community, and which allows the active participation of the crime’s stakeholders. It has the objective of ‘putting right’ the wrong done, to restore the broken relationship and to reintegrate the offender back into society. The Ethiopian criminal justice system views crime primarily as a violation of the state’s criminal laws, either in the form of a commission or omission. It excludes the community from participation, and gives no opportunity to the victim to fully participate in the process. Nor is there a satisfactory legal procedure which enables the public prosecutor to adequately protect the victim’s interest. The focus of the public prosecutor is to have the accused convicted and punished, instead of encouraging them to take responsibility to undo the wrong they have committed. This article thus examines whether restorative justice has a place in the formal legal framework of the existing Ethiopian criminal justice system; and analyses the prospects for, and the challenges that may hinder, the implementation of restorative justice practice in this framework.

  4. Optimal mechanical design of anatomical post-systems for endodontic restoration.

    Science.gov (United States)

    Maceri, Franco; Martignoni, Marco; Vairo, Giuseppe

    2009-02-01

    This paper analyses the mechanical behaviour of a new reinforced anatomical post-systems (RAPS) for endodontic restoration. The composite restorative material (CRM) completely fills the root canal (as do the commonly used cast metal posts) and multiple prefabricated composite posts (PCPs) are employed as reinforcements. Numerical simulations based on 3D linearly elastic finite element models under parafunctional loads were performed in order to investigate the influence of the stiffness of the CRM and of the number of PCPs. Periodontal ligament effects were taken into account using a discretised anisotropic nonlinearly elastic spring system, and the full discrete model was validated by comparing the resulting stress fields with those obtained with conventional restorations (cast gold-alloy post, homogeneous anatomical post and cemented single PCP) and with the natural tooth. Analysis of the results shows that stresses at the cervical/middle region decrease as CRM stiffness increases and, for large and irregular root cavities that apical stress peaks disappear when multiple PCPs are used. Accordingly, from a mechanical point of view, an optimal RAPS will use multiple PCPs when CRM stiffness is equal to or at most twice that of the dentin. This restorative solution minimises stress differences with respect to the natural tooth, mechanical inhomogeneities, stress concentrations on healthy tissues, volumes subject to shrinkage phenomena, fatigue effects and risks of both root fracture and adhesive/cohesive interfacial failure.

  5. Paradigms for restoration of somatosensory feedback via stimulation of the peripheral nervous system.

    Science.gov (United States)

    Pasluosta, Cristian; Kiele, Patrick; Stieglitz, Thomas

    2018-04-01

    The somatosensory system contributes substantially to the integration of multiple sensor modalities into perception. Tactile sensations, proprioception and even temperature perception are integrated to perceive embodiment of our limbs. Damage of somatosensory networks can severely affect the execution of daily life activities. Peripheral injuries are optimally corrected via direct interfacing of the peripheral nerves. Recent advances in implantable devices, stimulation paradigms, and biomimetic sensors enabled the restoration of natural sensations after amputation of the limb. The refinement of stimulation patterns to deliver natural feedback that can be interpreted intuitively such to prescind from long-learning sessions is crucial to function restoration. For this review, we collected state-of-the-art knowledge on the evolution of stimulation paradigms from single fiber stimulation to the eliciting of multisensory sensations. Data from the literature are structured into six sections: (a) physiology of the somatosensory system; (b) stimulation of single fibers; (c) restoral of multisensory percepts; (d) closure of the control loop in hand prostheses; (e) sensory restoration and the sense of embodiment, and (f) methodologies to assess stimulation outcomes. Full functional recovery demands further research on multisensory integration and brain plasticity, which will bring new paradigms for intuitive sensory feedback in the next generation of limb prostheses. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  6. The impact of low-temperature seasonal aquifer thermal energy storage (SATES) systems on chlorinated solvent contaminated groundwater: Modeling of spreading and degradation

    NARCIS (Netherlands)

    Zuurbier, K.G.; Hartog, N.; Valstar, J.; Post, V.E.A.; Breukelen, B.M. van

    2013-01-01

    Groundwater systems are increasingly used for seasonal aquifer thermal energy storage (SATES) for periodic heating and cooling of buildings. Its use is hampered in contaminated aquifers because of the potential environmental risks associated with the spreading of contaminated groundwater, but

  7. Golan Heights Groundwater Systems: Separation By REE+Y And Stable Isotopes

    Science.gov (United States)

    Siebert, C.; Geyer, S.; Knoeller, K.; Roediger, T.; Weise, S.; Dulski, P.; Moeller, P.; Guttman, J.

    2008-12-01

    In a semi-arid to arid country like Israel, all freshwater resources are under (over-) utilization. Particularly, the Golan Heights rank as one of the most important extraction areas of groundwater of good quality and quantity. Additionally the mountain range feed to a high degree the most important freshwater reservoir of Israel, the Sea of Galilee. Hence, knowing the sources and characters of the Golan Heights groundwater systems is an instantaneous demand regarding sustainable management and protection. Within the "German-Israeli-Jordanian-Palestinian Joint Research Program for the Sustainable Utilisation of Aquifer Systems", hundreds of water samples were taken from all over the Jordan-Dead Sea rift-system to understand groundwater flow-systems and salinisation. For that purpose, each sample was analysed for major and minor ions, rare earth elements including yttrium (REY) and stable isotopes of water (d18O, d2H). The REY distribution in groundwater is established during infiltration by the first water-rock interaction and consequently reflects the leachable components of sediments and rocks of the recharge area. In well- developed flow-systems, REY are adsorbed onto pore surfaces are in equilibrium with the percolating groundwater, even if the lithology changes (e.g. inter-aquifer flow). Thus, groundwater sampled from wells and springs still show the REY distribution pattern established in the recharge area. Since high temperatures do not occur in Golan Heights, d2H and d18O are less controlled by water-rock interaction than by climatic and geomorphological factors at the time of replenishment. Applying the REY signature as a grouping criterion of groundwaters, d18O vs. d2H plots yield a new dimension in interpreting isotope data. The combined use of hydrochemical and isotopic methods enabled us to contain the areas of replenishment and the flow-paths of all investigated groundwater in the Golan Heights. Despite location, salinity or temperature of spring or

  8. A cost/schedule and control system for the environmental restoration program Albuquerque Field Office

    International Nuclear Information System (INIS)

    Fiske, Wanda S.; Bischoff, Edward L.; Rea, Kenneth H.; Dwain Farley, P.; Biedermann, Charles A.

    1992-01-01

    The Department of Energy (DOE) Field Office Albuquerque (AL), Environmental Restoration Project Office (ERPO), has developed a project management system used to plan, document, and control Environmental Restoration (ER) work at eight installations and one superfund site managed by AL. This system emphasizes control of the cost, schedule, and technical elements of the Program. It supports programmatic documentation such as the Environmental Restoration/Waste Management Five-Year Plan, Site Specific Plan, and budget requests. The System provides information used to manage the ER Program at all levels of management (i.e., from low-level day-to-day activities to high-level upper management). The System requires substantial effort to ensure reliability; however, the benefit to ERPO is an effective, proactive project management tool. This paper provides an overview of the ERPO System, an explanation of how it is implemented, and lessons learned from this process. Application of the System to cost estimating, annual and five-year budget preparation, resource projections, scheduling, and cost/schedule performance measurement is discussed. Also discussed are cost/schedule review procedures, along with variance identification and resolution. Examples are taken from the Pinellas ER Program. (author)

  9. SYSTEMIC APPROACH AND ROUGHNESS APPLICATION TO CAUSE EMERGING PROPERTIES IN THE RESTORATION OF DEGRADED SOILS

    Directory of Open Access Journals (Sweden)

    Juarês José Aumond

    2014-09-01

    Full Text Available http://dx.doi.org/10.5902/1980509815737Based on the general systems theory, an ecological model for the restoration of ecosystems has been developed, which soils are highly degraded, and treating the ecosystem as a complex dynamic system, hyper-sensitive to initial conditions of soil preparation. Assuming that degraded ecosystems are sensitive to initial conditions of soil preparation, the technique of roughness was evaluated (relief variations alternating between concave and convex surfaces to trigger over time emergent properties that accelerate the process of ecological restoration. The degraded ecosystems can be understood as organizationally open systems, as a dissipative structure, in which irreversibly matter and energy flow. The main task in ecological restoration in areas that had the soil degraded is to achieve the internalization of matter and energy to induce the system to organizational closure. The roughness, represented by soil micro-topography is an effective technique in the internalization of matter, retaining water, sediment, organic matter, nutrients and seeds. Variations of relief trigger environmental changes over time in a dynamic and heterogeneous way, which influence the interactions between solar radiation, moisture and nutrients, creating different opportunities for plants and animal species. There must be an oriented concentration to flow structures and processes between the degraded ecosystem (system and the environment (neighborhood. In this approach, a particular concentration on the interrelationships between the system and the environment is dedicated. For ecological restoration, whose area is with degraded soil, such as mining and ranching, a new integrative degraded systemic approach is proposed, in which the roughness of the soil might trigger spatial and temporal patterns and emergent environmental properties due to the hyper-sensitivity to initial conditions of the land preparation.

  10. Evaluation of the Validity of Groundwater Samples Obtained Using the Purge Water Management System at SRS

    International Nuclear Information System (INIS)

    Beardsley, C.C.

    1999-01-01

    As part of the demonstration testing of the Purge Water Management System (PWMS) technology at the Savannah River Site (SRS), four wells were equipped with PWMS units in 1997 and a series of sampling events were conducted at each during 1997-1998. Three of the wells were located in A/M Area while the fourth was located at the Old Radioactive Waste Burial Ground in the General Separations Area.The PWMS is a ''closed-loop'', non-contact, system used to collect and return purge water to the originating aquifer after a sampling event without having significantly altered the water quality. One of the primary concerns as to its applicability at SRS, and elsewhere, is whether the PWMS might resample groundwater that is returned to the aquifer during the previous sampling event. The purpose of the present investigation was to compare groundwater chemical analysis data collected at the four test wells using the PWMS vs. historical data collected using the standard monitoring program methodology to determine if the PWMS provides representative monitoring samples.The analysis of the groundwater chemical concentrations indicates that the PWMS sampling methodology acquired representative groundwater samples at monitoring wells ABP-1A, ABP-4, ARP-3 and BGO-33C. Representative groundwater samples are achieved if the PWMS does not resample groundwater that has been purged and returned during a previous sampling event. Initial screening calculations, conducted prior to the selection of these four wells, indicated that groundwater velocities were high enough under the ambient hydraulic gradients to preclude resampling from occurring at the time intervals that were used at each well. Corroborating evidence included a tracer test that was conducted at BGO-33C, the high degree of similarity between analyte concentrations derived from the PWMS samples and those obtained from historical protocol sampling, as well as the fact that PWMS data extend all previously existing concentration

  11. Three-dimensional geologic modeling and groundwater flow modeling of the Töllinperä aquifer in the Hitura nickel mine area, Finland – providing the framework for restoration and protection of the aquifer

    Directory of Open Access Journals (Sweden)

    Sami Saraperä

    2004-01-01

    Full Text Available Elevated concentrations of sulphate, chloride, and nickel were discovered in water samples taken from the Töllinperä aquifer in western Finland. The area is located adjacent to the tailings area of the Hitura nickel mine. Earlier studies revealed that the groundwater contamination resulted from tailings-derived mine waters leaking from a tailings impoundment area. The tailings area directly overlies the Weichselian esker system, part of which is the Töllinperä classified groundwater area. The observed groundwater and surface water contamination resulted in a need to characterize the subsurface geology in the whole area of the contaminated esker aquifer. The primary sedimentary units were introduced into a three-dimensional (3-D geologic model of the aquifer made with EarthVision geologic modeling software. The information obtained from the 3-D geological model was then introduced into a numerical groundwater flow model made with MODFLOW code, which was calibrated with MODFLOWP code.The results of this study were used to guide the sealing of the tailings impoundment in order to prevent the further contamination of the Töllinperä aquifer. The groundwater flow model was used to interpret and simulate the flow system, and to provide a plan to safely continue water supply to local inhabitants from the unpolluted parts of the aquifer.

  12. Electronic document management system analysis report and system plan for the Environmental Restoration Program

    International Nuclear Information System (INIS)

    Frappaolo, C.

    1995-09-01

    Lockheed Martin Energy Systems, Inc. (LMES) has established and maintains Document Management Centers (DMCs) to support Environmental Restoration Program (ER) activities undertaken at three Oak Ridge facilities: Oak Ridge National Laboratory, Oak Ridge K-25 Site, Oak Ridge Y-12 Plant; and two sister sites: Portsmouth Gaseous Diffusion Plant in Portsmouth, Ohio, and Paducah Gaseous Diffusion Plant in Paducah, Kentucky. The role of the DMCs is to receive, store, retrieve, and properly dispose of records. In an effort to make the DMCs run more efficiently and to more proactively manage the records' life cycles from cradle to grave, ER has decided to investigate ways in which Electronic Document Management System (EDMS) technologies can be used to redefine the DMCs and their related processes. Specific goals of this study are tightening control over the ER documents, establishing and enforcing record creation and retention procedures, speeding up access to information, and increasing the accessibility of information. A working pilot of the solution is desired within the next six months. Based on a series of interviews conducted with personnel from each of the DMCs, key management, and individuals representing related projects, it is recommended that ER utilize document management, full-text retrieval, and workflow technologies to improve and automate records management for the ER program. A phased approach to solution implementation is suggested starting with the deployment of an automated storage and retrieval system at Portsmouth. This should be followed with a roll out of the system to the other DMCs, the deployment of a workflow-enabled authoring system at Portsmouth, and a subsequent roll out of this authoring system to the other sites

  13. A conceptual model for the analysis of multi-stressors in linked groundwater-surface water systems.

    Science.gov (United States)

    Kaandorp, Vince P; Molina-Navarro, Eugenio; Andersen, Hans E; Bloomfield, John P; Kuijper, Martina J M; de Louw, Perry G B

    2018-06-15

    Groundwater and surface water are often closely coupled and are both under the influence of multiple stressors. Stressed groundwater systems may lead to a poor ecological status of surface waters but to date no conceptual framework to analyse linked multi-stressed groundwater - surface water systems has been developed. In this paper, a framework is proposed showing the effect of groundwater on surface waters in multiple stressed systems. This framework will be illustrated by applying it to four European catchments, the Odense, Denmark, the Regge and Dinkel, Netherlands, and the Thames, UK, and by assessing its utility in analysing the propagation or buffering of multi-stressors through groundwater to surface waters in these catchments. It is shown that groundwater affects surface water flow, nutrients and temperature, and can both propagate stressors towards surface waters and buffer the effect of stressors in space and time. The effect of groundwater on drivers and states depends on catchment characteristics, stressor combinations, scale and management practises. The proposed framework shows how groundwater in lowland catchments acts as a bridge between stressors and their effects within surface waters. It shows water managers how their management areas might be influenced by groundwater, and helps them to include this important, but often overlooked part of the water cycle in their basin management plans. The analysis of the study catchments also revealed a lack of data on the temperature of both groundwater and surface water, while it is an important parameter considering future climate warming. Copyright © 2018. Published by Elsevier B.V.

  14. Identifying three-dimensional nested groundwater flow systems in a Tóthian basin

    Science.gov (United States)

    Wang, Xu-Sheng; Wan, Li; Jiang, Xiao-Wei; Li, Hailong; Zhou, Yangxiao; Wang, Junzhi; Ji, Xiaohui

    2017-10-01

    Nested groundwater flow systems have been revealed in Tóth's theory as the structural property of basin-scale groundwater circulation but were only well known with two-dimensional (2D) profile models. The method of searching special streamlines across stagnation points for partitioning flow systems, which has been successfully applied in the 2D models, has never been implemented for three-dimensional (3D) Tóthian basins because of the difficulty in solving the dual stream functions. Alternatively, a new method is developed to investigate 3D nested groundwater flow systems without determination of stagnation points. Connective indices are defined to quantify the connection between individual recharge and discharge zones along streamlines. Groundwater circulation cells (GWCCs) are identified according to the distribution of the connective indices and then grouped into local, intermediate and regional flow systems. This method requires existing solution of the flow velocity vector and is implemented via particle tracking technique. It is applied in a hypothetical 3D Tóthian basin with an analytical solution of the flow field and in a real-world basin with a numerical modeling approach. Different spatial patterns of flow systems compared to 2D profile models are found. The outcrops boundaries of GWCCs on water table may significantly deviate from and are not parallel to the nearby water table divides. Topological network is proposed to represent the linked recharge-discharge zones through closed and open GWCCs. Sensitivity analysis indicates that the development of GWCCs depends on the basin geometry, hydraulic parameters and water table shape.

  15. EUGRIS: ''European Substainable Land and Groundwater Management Information System''

    Energy Technology Data Exchange (ETDEWEB)

    Frauenstein, J. [Federal Environmental Agency (UBA), Berlin (Germany)

    2003-07-01

    The presentation outlines and Accompanying Measure with the FP 5 to develop an web based EUropean Sustainable Land and GRoundwater Management Information System information system (EUGRIS). The management of contaminated land and groundwater requires an interdisciplinary approach and a considerable amount of supporting technical information and knowledge. EUGRIS will provide a generally available comprehensive and overarching information and innovation resource, to support both research and practical contaminated land and groundwater management. EUGRI is a gateway to provide a 'one stop shop' for information provided by research projects, legislation, standards, best practice and other technical guidance and policy/regulatory publications from the EC, participating Member and Accession States and from various international networks dealing with groundwater and land management issues. Different types of user can access information through different windows according to their needs. EUGRIS will provide its visitors with summary information (digests) and links to sources of more detailed and/or original information in a scaleable holistic and contexturally meaningful way. EUGRIS is being built in three stages: the design of the information system, the development of its software implementation, and the population of the system with information. The presentation is focussed on the concept of the development of the information system with the individual work packages. In the second part of the lecture in particular the work procedures are presented for the content wise replenishment by EUGRIS. The data collation for the proven pilot countries and the production of a European research data base, which opens contents and results of European-wide locked and current projects, form the emphasis thereby. (orig.)

  16. An approach for classification of hydrogeological systems at the regional scale based on groundwater hydrographs

    Science.gov (United States)

    Haaf, Ezra; Barthel, Roland

    2016-04-01

    When assessing hydrogeological conditions at the regional scale, the analyst is often confronted with uncertainty of structures, inputs and processes while having to base inference on scarce and patchy data. Haaf and Barthel (2015) proposed a concept for handling this predicament by developing a groundwater systems classification framework, where information is transferred from similar, but well-explored and better understood to poorly described systems. The concept is based on the central hypothesis that similar systems react similarly to the same inputs and vice versa. It is conceptually related to PUB (Prediction in ungauged basins) where organization of systems and processes by quantitative methods is intended and used to improve understanding and prediction. Furthermore, using the framework it is expected that regional conceptual and numerical models can be checked or enriched by ensemble generated data from neighborhood-based estimators. In a first step, groundwater hydrographs from a large dataset in Southern Germany are compared in an effort to identify structural similarity in groundwater dynamics. A number of approaches to group hydrographs, mostly based on a similarity measure - which have previously only been used in local-scale studies, can be found in the literature. These are tested alongside different global feature extraction techniques. The resulting classifications are then compared to a visual "expert assessment"-based classification which serves as a reference. A ranking of the classification methods is carried out and differences shown. Selected groups from the classifications are related to geological descriptors. Here we present the most promising results from a comparison of classifications based on series correlation, different series distances and series features, such as the coefficients of the discrete Fourier transform and the intrinsic mode functions of empirical mode decomposition. Additionally, we show examples of classes

  17. Development and implementation of a comprehensive groundwater protection program at the Savannah River Plant

    International Nuclear Information System (INIS)

    Gordon, D.E.

    1984-01-01

    The major goals of the groundwater protection program are to evaluate the impact on groundwater quality as a result of Savannah River Plant operations, to take corrective measures as required to restore or protect groundwater quality, and to ensure that future operations do not adversely affect the quality or availability of the groundwater resources at the site. The specific elements of this program include (1) continuation of an extensive groundwater monitoring program, (2) assessment of waste disposal sites for impacts on groundwater quality, (3) implementation of mitigative actions, as required, to restore or protect groundwater quality, (4) incorporation of groundwater protection concepts in the design of new production and waste management facilities, and (5) review of site utilization of groundwater resources to ensure compatibility with regional needs. The major focal points of the groundwater protection program are the assessment of waste disposal sites for impacts on groundwater quality and the implementation of remedial action projects. Many locations at SRP have been used as waste disposal sites for a variety of liquid and solid wastes. Field investigations are ongoing to determine the nature and extent of any contamination in the sediments and groundwater at these waste sites on a priority basis. Remedial action has been initiated. Certain aspects of the groundwater protection program have been identified as key to the success in achieving the desired objectives. Key elements of the program have included early identification of all the potential sources for groundwater contamination, development of an overall strategy for waste site assessment and mitigation, use of a flexible computerized system for data base management, and establishing good relationships with regulatory agencies. 10 references, 6 figures, 4 tables

  18. Groundwater infiltration, surface water inflow and sewerage exfiltration considering hydrodynamic conditions in sewer systems.

    Science.gov (United States)

    Karpf, Christian; Hoeft, Stefan; Scheffer, Claudia; Fuchs, Lothar; Krebs, Peter

    2011-01-01

    Sewer systems are closely interlinked with groundwater and surface water. Due to leaks and regular openings in the sewer system (e.g. combined sewer overflow structures with sometimes reverse pressure conditions), groundwater infiltration and surface water inflow as well as exfiltration of sewage take place and cannot be avoided. In the paper a new hydrodynamic sewer network modelling approach will be presented, which includes--besides precipitation--hydrographs of groundwater and surface water as essential boundary conditions. The concept of the modelling approach and the models to describe the infiltration, inflow and exfiltration fluxes are described. The model application to the sewerage system of the City of Dresden during a flood event with complex conditions shows that the processes of infiltration, exfiltration and surface water inflows can be described with a higher reliability and accuracy, showing that surface water inflow causes a pronounced system reaction. Further, according to the simulation results, a high sensitivity of exfiltration rates on the in-sewer water levels and a relatively low influence of the dynamic conditions on the infiltration rates were found.

  19. Model-based restoration using light vein for range-gated imaging systems.

    Science.gov (United States)

    Wang, Canjin; Sun, Tao; Wang, Tingfeng; Wang, Rui; Guo, Jin; Tian, Yuzhen

    2016-09-10

    The images captured by an airborne range-gated imaging system are degraded by many factors, such as light scattering, noise, defocus of the optical system, atmospheric disturbances, platform vibrations, and so on. The characteristics of low illumination, few details, and high noise make the state-of-the-art restoration method fail. In this paper, we present a restoration method especially for range-gated imaging systems. The degradation process is divided into two parts: the static part and the dynamic part. For the static part, we establish the physical model of the imaging system according to the laser transmission theory, and estimate the static point spread function (PSF). For the dynamic part, a so-called light vein feature extraction method is presented to estimate the fuzzy parameter of the atmospheric disturbance and platform movement, which make contributions to the dynamic PSF. Finally, combined with the static and dynamic PSF, an iterative updating framework is used to restore the image. Compared with the state-of-the-art methods, the proposed method can effectively suppress ringing artifacts and achieve better performance in a range-gated imaging system.

  20. Restoring nervous system structure and function using tissue engineered living scaffolds

    Institute of Scientific and Technical Information of China (English)

    Laura A Struzyna; James P Harris; Kritika S Katiyar; H Isaac Chen; D KacyCullen

    2015-01-01

    Neural tissue engineering is premised on the integration of engineered living tissue with the host nervous system to directly restore lost function or to augment regenerative capacity following ner-vous system injury or neurodegenerative disease. Disconnection of axon pathways – the long-distance ifbers connecting specialized regions of the central nervous system or relaying peripheral signals – is a common feature of many neurological disorders and injury. However, functional axonal regenera-tion rarely occurs due to extreme distances to targets, absence of directed guidance, and the presence of inhibitory factors in the central nervous system, resulting in devastating effects on cognitive and sensorimotor function. To address this need, we are pursuing multiple strategies using tissue engi-neered “living scaffolds”, which are preformed three-dimensional constructs consisting of living neural cells in a deifned, often anisotropic architecture. Living scaffolds are designed to restore function by serving as a living labeled pathway for targeted axonal regeneration – mimicking key developmental mechanisms– or by restoring lost neural circuitry via direct replacement of neurons and axonal tracts. We are currently utilizing preformed living scaffolds consisting of neuronal clusters spanned by long axonal tracts as regenerative bridges to facilitate long-distance axonal regeneration and for targeted neurosurgical reconstruction of local circuits in the brain. Although there are formidable challenges in preclinical and clinical advancement, these living tissue engineered constructs represent a promising strategy to facilitate nervous system repair and functional recovery.

  1. Restoring nervous system structure and function using tissue engineered living scaffolds

    Directory of Open Access Journals (Sweden)

    Laura A Struzyna

    2015-01-01

    Full Text Available Neural tissue engineering is premised on the integration of engineered living tissue with the host nervous system to directly restore lost function or to augment regenerative capacity following nervous system injury or neurodegenerative disease. Disconnection of axon pathways - the long-distance fibers connecting specialized regions of the central nervous system or relaying peripheral signals - is a common feature of many neurological disorders and injury. However, functional axonal regeneration rarely occurs due to extreme distances to targets, absence of directed guidance, and the presence of inhibitory factors in the central nervous system, resulting in devastating effects on cognitive and sensorimotor function. To address this need, we are pursuing multiple strategies using tissue engineered "living scaffolds", which are preformed three-dimensional constructs consisting of living neural cells in a defined, often anisotropic architecture. Living scaffolds are designed to restore function by serving as a living labeled pathway for targeted axonal regeneration - mimicking key developmental mechanisms- or by restoring lost neural circuitry via direct replacement of neurons and axonal tracts. We are currently utilizing preformed living scaffolds consisting of neuronal clusters spanned by long axonal tracts as regenerative bridges to facilitate long-distance axonal regeneration and for targeted neurosurgical reconstruction of local circuits in the brain. Although there are formidable challenges in preclinical and clinical advancement, these living tissue engineered constructs represent a promising strategy to facilitate nervous system repair and functional recovery.

  2. Criminal Justice System of Children in The Law Number 11 of 2012 (Restorative Justice

    Directory of Open Access Journals (Sweden)

    Ansori Ansori

    2014-01-01

    Full Text Available The future of the children will determine the future of the nation. The increasing problem of juvenile delinquency in this globalization and information technology era, requires the state to give more attention to the child's future. Application of the criminal justice system for children in Indonesia is as stipulated in Law Number 3 of 1997 potentially detrimental to the child's interests. In practice, the judicial system had many problems, among them is a violation of the rights of children, such as: physical and psychological violence, as well as deprivation of the right to education and welfare. It happened because the juvenile justice system is against to national and international regulations on the protection of children’s rights. Besides that, theory of punishment for the juvenile delinquency still refers to the concept of retribution for the crimes. This concept is not very useful for the development of the child, so the concept need to be repaired with the concept of restorative justice. With this concept, the criminal justice system for the juvenile delinquency, leads to the restoration of the state and the settlement pattern, involving the perpetrator, the victim, their families and engage with the community. This is done with consideration for the protection of children against the law. Whereas in line with this spirit of the restorative justice, it gives birth to the Law No. 11 of 2012 on The Criminal Justice System of Children. How To Cite: Ansori, A. (2014. Criminal Justice System of Children in The Law Number 11 of 2012 (Restorative Justice. Rechtsidee, 1(1, 11-26. doi:http://dx.doi.org/10.21070/jihr.v1i1.95

  3. The `Henry Problem' of `density-driven' groundwater flow versus Tothian `groundwater flow systems' with variable density: A review of the influential Biscayne aquifer data.

    Science.gov (United States)

    Weyer, K. U.

    2017-12-01

    Coastal groundwater flow investigations at the Biscayne Bay, south of Miami, Florida, gave rise to the concept of density-driven flow of seawater into coastal aquifers creating a saltwater wedge. Within that wedge, convection-driven return flow of seawater and a dispersion zone were assumed by Cooper et al. (1964) to be the cause of the Biscayne aquifer `sea water wedge'. This conclusion was based on the chloride distribution within the aquifer and on an analytical model concept assuming convection flow within a confined aquifer without taking non-chemical field data into consideration. This concept was later labelled the `Henry Problem', which any numerical variable density flow program must be able to simulate to be considered acceptable. Both, `density-driven flow' and Tothian `groundwater flow systems' (with or without variable density conditions) are driven by gravitation. The difference between the two are the boundary conditions. 'Density-driven flow' occurs under hydrostatic boundary conditions while Tothian `groundwater flow systems' occur under hydrodynamic boundary conditions. Revisiting the Cooper et al. (1964) publication with its record of piezometric field data (heads) showed that the so-called sea water wedge has been caused by discharging deep saline groundwater driven by gravitational flow and not by denser sea water. Density driven flow of seawater into the aquifer was not found reflected in the head measurements for low and high tide conditions which had been taken contemporaneously with the chloride measurements. These head measurements had not been included in the flow interpretation. The very same head measurements indicated a clear dividing line between shallow local fresh groundwater flow and saline deep groundwater flow without the existence of a dispersion zone or a convection cell. The Biscayne situation emphasizes the need for any chemical interpretation of flow pattern to be supported by head data as energy indicators of flow fields

  4. Modelling the geochemical fate and transport of wastewater-derived phosphorus in contrasting groundwater systems

    Science.gov (United States)

    Spiteri, Claudette; Slomp, Caroline P.; Regnier, Pierre; Meile, Christof; Van Cappellen, Philippe

    2007-06-01

    A 1D reactive transport model (RTM) is used to obtain a mechanistic understanding of the fate of phosphorus (P) in the saturated zone of two contrasting aquifer systems. We use the field data from two oxic, electron donor-poor, wastewater-impacted, sandy Canadian aquifers, (Cambridge and Muskoka sites) as an example of a calcareous and non-calcareous groundwater system, respectively, to validate our reaction network. After approximately 10 years of wastewater infiltration, P is effectively attenuated within the first 10 m downgradient of the source mainly through fast sorption onto calcite and Fe oxides. Slow, kinetic sorption contributes further to P removal, while precipitation of phosphate minerals (strengite, hydroxyapatite) is quantitatively unimportant in the saturated zone. Nitrogen (N) dynamics are also considered, but nitrate behaves essentially as a conservative tracer in both systems. The model-predicted advancement of the P plume upon continued wastewater discharge at the calcareous site is in line with field observations. Model results suggest that, upon removal of the wastewater source, the P plume at both sites will persist for at least 20 years, owing to desorption of P from aquifer solids and the slow rate of P mineral precipitation. Sensitivity analyses for the non-calcareous scenario (Muskoka) illustrate the importance of the sorption capacity of the aquifer solids for P in modulating groundwater N:P ratios in oxic groundwater. The model simulations predict the breakthrough of groundwater with high P concentrations and low N:P ratios after 17 years at 20 m from the source for an aquifer with low sorption capacity (< 0.02% w/w Fe(OH) 3). In this type of system, denitrification plays a minor role in lowering the N:P ratios because it is limited by the availability of labile dissolved organic matter.

  5. Quantitative evaluation of flow systems, groundwater recharge and transmissivities using environmental tracers

    Energy Technology Data Exchange (ETDEWEB)

    Adar, E M [Ben-Gurion Univ. of Negev, Sede Boker Campus (Israel). Water Resources Center

    1996-10-01

    This chapter provides an overview of the basic concepts and formulations on the compartmental (mixing-cell) approach for interpretation of isotope and natural tracer data to arrive at quantitative estimates related to groundwater systems. The theoretical basis of the models and the specific solution algorithms used are described. The application of this approach to field cases are described as illustrative examples. Results of sensitivity analyses of the model to different parameters are provided. (author). 81 refs, 13 figs, 8 tabs.

  6. Quantitative evaluation of flow systems, groundwater recharge and transmissivities using environmental tracers

    International Nuclear Information System (INIS)

    Adar, E.M.

    1996-01-01

    This chapter provides an overview of the basic concepts and formulations on the compartmental (mixing-cell) approach for interpretation of isotope and natural tracer data to arrive at quantitative estimates related to groundwater systems. The theoretical basis of the models and the specific solution algorithms used are described. The application of this approach to field cases are described as illustrative examples. Results of sensitivity analyses of the model to different parameters are provided. (author). 81 refs, 13 figs, 8 tabs

  7. Potential Offshore Submarine Groundwater in the Albufeira-Ribeira de Quarteira aquifer system (Algarve, Portugal)

    Science.gov (United States)

    Hugman, Rui; Stigter, Tibor; Monteiro, Jose Paulo

    2015-04-01

    The Albufeira-Ribeira de Quarteira aquifer system on the south coast of Portugal is an important source of groundwater for agriculture and tourism, as well as contributing to significant freshwater discharge along the coast in the form of inter- and sub-tidal springs and maintaining groundwater dependent ecosystems along the Quarteira stream. Submarine groundwater discharge (SGD) in the area was investigated within the scope of a multidisciplinary research project FREEZE (PTDC/MAR/102030/2008) which aimed to identify and characterize the effects of the hydrological/hydrogeological conditions on associated ecosystems. As well as near shore submarine springs, signs of SGD were found several kilometres from the shoreline during offshore CTD and geophysical surveys. On-land geophysical and offshore seismic surveys supplied data to update the 3D hydrogeological conceptual model of the aquifer system. Numerical models were applied to test the possibility of an offshore continuation of fresh groundwater over several kilometres under local conditions. Due to the high computational demand of variable density modelling, in an initial phase simplified 2D cross section models were used to test the conceptual model and reduce uncertainty in regards to model parameters. Results confirm the potential for SGD several kilometres from the coast within a range of acceptable values of hydraulic conductivity and recharge of the system. This represents the initial step in developing and calibrating a 3D regional scale model of the system, which aims to supply an estimate of the spatial distribution of SGD as well as serve as a decision support tool for the local water resources management agency.

  8. Temperature distribution by the effect of groundwater flow in an aquifer thermal energy storage system model

    Science.gov (United States)

    Shim, B.

    2005-12-01

    Aquifer thermal energy storage (ATES) can be a cost-effective and renewable energy source, depending on site-specific thermohydraulic conditions. To design an effective ATES system, the understanding of thermohydraulic processes is necessary. The heat transfer phenomena of an aquifer heat storage system are simulated with the scenario of heat pump operation of pumping and waste water reinjection in a two layered confined aquifer model having the effect of groundwater movement. Temperature distribution of the aquifer model is generated, and hydraulic heads and temperature variations are monitored at both wells during simulation days. The average groundwater velocities are determined with two assumed hydraulic gradients set by boundary conditions, and the effect of groundwater flow are shown at the generated thermal distributions at three different depth slices. The generated temperature contour lines at the hydraulic gradient of 0.001 are shaped circular, and the center is moved less than 5 m to the east in 365 days. However at the hydraulic gradient of 0.01, the contour centers of the east well at each depth slice are moved near the east boundary and the movement of temperature distribution is increased at the lower aquifer. By the analysis of thermal interference data between two wells the efficiency of a heat pump operation model is validated, and the variation of heads is monitored at injection, pumping and stabilized state. The thermal efficiency of the ATES system model is represented as highly depended on groundwater flow velocity and direction. Therefore the hydrogeologic condition for the system site should be carefully surveyed.

  9. 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

  10. Multi-Time Step Service Restoration for Advanced Distribution Systems and Microgrids

    International Nuclear Information System (INIS)

    Chen, Bo; Chen, Chen; Wang, Jianhui; Butler-Purry, Karen L.

    2017-01-01

    Modern power systems are facing increased risk of disasters that can cause extended outages. The presence of remote control switches (RCSs), distributed generators (DGs), and energy storage systems (ESS) provides both challenges and opportunities for developing post-fault service restoration methodologies. Inter-temporal constraints of DGs, ESS, and loads under cold load pickup (CLPU) conditions impose extra complexity on problem formulation and solution. In this paper, a multi-time step service restoration methodology is proposed to optimally generate a sequence of control actions for controllable switches, ESSs, and dispatchable DGs to assist the system operator with decision making. The restoration sequence is determined to minimize the unserved customers by energizing the system step by step without violating operational constraints at each time step. The proposed methodology is formulated as a mixed-integer linear programming (MILP) model and can adapt to various operation conditions. Furthermore, the proposed method is validated through several case studies that are performed on modified IEEE 13-node and IEEE 123-node test feeders.

  11. Semi-Markov models control of restorable systems with latent failures

    CERN Document Server

    Obzherin, Yuriy E

    2015-01-01

    Featuring previously unpublished results, Semi-Markov Models: Control of Restorable Systems with Latent Failures describes valuable methodology which can be used by readers to build mathematical models of a wide class of systems for various applications. In particular, this information can be applied to build models of reliability, queuing systems, and technical control. Beginning with a brief introduction to the area, the book covers semi-Markov models for different control strategies in one-component systems, defining their stationary characteristics of reliability and efficiency, and uti

  12. Assessment of On-site sanitation system on local groundwater regime in an alluvial aquifer

    Science.gov (United States)

    Quamar, Rafat; Jangam, C.; Veligeti, J.; Chintalapudi, P.; Janipella, R.

    2017-12-01

    The present study is an attempt to study the impact of the On-site sanitation system on the groundwater sources in its vicinity. The study has been undertaken in the Agra city of Yamuna sub-basin. In this context, sampling sites (3 nos) namely Pandav Nagar, Ayodhya Kunj and Laxmi Nagar were selected for sampling. The groundwater samples were analyzed for major cations, anions and faecal coliform. Critical parameters namely chloride, nitrate and Faecal coliform were considered to assess the impact of the On-site sanitation systems. The analytical results shown that except for chloride, most of the samples exceeded the Bureau of Indian Standard limits for drinking water for all the other analyzed parameters, i.e., nitrate and faecal coliform in the first two sites. In Laxmi Nagar, except for faecal coliform, all the samples are below the BIS limits. In all the three sites, faecal coliform was found in majority of the samples. A comparison of present study indicates that the contamination of groundwater in alluvial setting is less as compared to hard rock where On-site sanitation systems have been implemented.

  13. Simulating Salt Movement using a Coupled Salinity Transport Model in a Variably Saturated Agricultural Groundwater System

    Science.gov (United States)

    Tavakoli Kivi, S.; Bailey, R. T.; Gates, T. K.

    2017-12-01

    Salinization is one of the major concerns in irrigated agricultural fields. Increasing salinity concentrations are due principally to a high water table that results from excessive irrigation, canal seepage, and a lack of efficient drainage systems, and lead to decreasing crop yield. High groundwater salinity loading to nearby river systems also impacts downstream areas, with saline river water diverted for application on irrigated fields. To assess the different strategies for salt remediation, we present a reactive transport model (UZF-RT3D) coupled with a salinity equilibrium chemistry module for simulating the fate and transport of salt ions in a variably-saturated agricultural groundwater system. The developed model accounts not for advection, dispersion, nitrogen and sulfur cycling, oxidation-reduction, sorption, complexation, ion exchange, and precipitation/dissolution of salt minerals. The model is applied to a 500 km2 region within the Lower Arkansas River Valley (LARV) in southeastern Colorado, an area acutely affected by salinization in the past few decades. The model is tested against salt ion concentrations in the saturated zone, total dissolved solid concentrations in the unsaturated zone, and salt groundwater loading to the Arkansas River. The model now can be used to investigate salinity remediation strategies.

  14. Groundwater availability of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Vaccaro, J.J.; Kahle, S.C.; Ely, D.M.; Burns, E.R.; Snyder, D.T.; Haynes, J.V.; Olsen, T.D.; Welch, W.B.; Morgan, D.S.

    2015-09-22

    The Columbia Plateau Regional Aquifer System (CPRAS) covers about 44,000 square miles of southeastern Washington, northeastern Oregon, and western Idaho. The area supports a $6-billion per year agricultural industry, leading the Nation in production of apples, hops, and eight other commodities. Groundwater pumpage and surface-water diversions supply water to croplands that account for about 5 percent of the Nation’s irrigated lands. Groundwater also is the primary source of drinking water for the more than 1.3 million people in the study area. Increasing competitive demands for water for municipal, fisheries/ecosystems, agricultural, domestic, hydropower, and recreational uses must be met by additional groundwater withdrawals and (or) by changes in the way water resources are allocated and used throughout the hydrologic system. As of 2014, most surface-water resources in the study area were either over allocated or fully appropriated, especially during the dry summer season. In response to continued competition for water, numerous water-management activities and concerns have gained prominence: water conservation, conjunctive use, artificial recharge, hydrologic implications of land-use change, pumpage effects on streamflow, and effects of climate variability and change. An integrated understanding of the hydrologic system is important in order to implement effective water-resource management strategies that address these concerns.

  15. System dynamic modelling to assess economic viability and risk trade-offs for ecological restoration in South Africa.

    Science.gov (United States)

    Crookes, D J; Blignaut, J N; de Wit, M P; Esler, K J; Le Maitre, D C; Milton, S J; Mitchell, S A; Cloete, J; de Abreu, P; Fourie nee Vlok, H; Gull, K; Marx, D; Mugido, W; Ndhlovu, T; Nowell, M; Pauw, M; Rebelo, A

    2013-05-15

    Can markets assist by providing support for ecological restoration, and if so, under what conditions? The first step in addressing this question is to develop a consistent methodology for economic evaluation of ecological restoration projects. A risk analysis process was followed in which a system dynamics model was constructed for eight diverse case study sites where ecological restoration is currently being pursued. Restoration costs vary across each of these sites, as do the benefits associated with restored ecosystem functioning. The system dynamics model simulates the ecological, hydrological and economic benefits of ecological restoration and informs a portfolio mapping exercise where payoffs are matched against the likelihood of success of a project, as well as a number of other factors (such as project costs and risk measures). This is the first known application that couples ecological restoration with system dynamics and portfolio mapping. The results suggest an approach that is able to move beyond traditional indicators of project success, since the effect of discounting is virtually eliminated. We conclude that systems dynamic modelling with portfolio mapping can guide decisions on when markets for restoration activities may be feasible. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. The fluoride in the groundwater of Guarani Aquifer System: the origin associated with black shales of Paraná Basin

    Science.gov (United States)

    Kern, M. L.; Vieiro, A. P.; Machado, G.

    2008-09-01

    This work presents petrological and geochemical results of the black shales interval from Permian and Devonian strata of the Paraná Basin, Brazil and its relationships with fluoride of groundwater from Guarani Aquifer System. The Guarani Aquifer, located in South Brazil, Uruguay, Paraguay and Argentine, presents contents of fluoride higher than the Brazilian accepted potability limits. Several hypotheses have been presented for the origin of the fluoride in the groundwater of the Guarani Aquifer. Microcrystalline fluorite was registered in black shales of Ponta Grossa and Irati formations from Paraná Basin. The results shown in this work suggest that fluoride present in groundwater of Guarani Aquifer can be originated in deeper groundwater that circulates in Ponta Grossa and Irati formations. The interaction of the groundwater coming from deeper black shales with the groundwater-bearing Aquifer Guarani System occurs through regional fragile structures (faults and fractures) that constitute excellent hydraulic connectors between the two sedimentary packages. The microcrystalline fluorite registered in Ponta Grossa and Irati Formations can be dissolved promoting fluoride enrichment in groundwater of these black shales and Guarani Aquifer System.

  17. Ecohydrological Investigations of a Groundwater-Lake System

    DEFF Research Database (Denmark)

    Frandsen, Mette Cristine Schou

    are very dynamic systems on a spatial scale. Variability in meteorology can lead to variability in the hydrology, and in some cases ignite transient effects that are temporally distinct and difficult to capture. •To some extend the lakes acts as sentinel for all the in and out-puts to the system as well....... On densely vegetated areas (~9000 plants m-2), the vertical hydraulic conductivity was lower compared to non-vegetated sediment. Disturbing the top layer of the sediment lead to a significant increase in hydraulic conductivity on the vegetated sediment, whereas the non-vegetated sediment was not affected...... greatly qualifies the results of ecological studies....

  18. Sensitivity of the Gravity Recovery and Climate Experiment (GRACE) to the complexity of aquifer systems for monitoring of groundwater

    Science.gov (United States)

    Katpatal, Yashwant B.; Rishma, C.; Singh, Chandan K.

    2018-05-01

    The Gravity Recovery and Climate Experiment (GRACE) satellite mission is aimed at assessment of groundwater storage under different terrestrial conditions. The main objective of the presented study is to highlight the significance of aquifer complexity to improve the performance of GRACE in monitoring groundwater. Vidarbha region of Maharashtra, central India, was selected as the study area for analysis, since the region comprises a simple aquifer system in the western region and a complex aquifer system in the eastern region. Groundwater-level-trend analyses of the different aquifer systems and spatial and temporal variation of the terrestrial water storage anomaly were studied to understand the groundwater scenario. GRACE and its field application involve selecting four pixels from the GRACE output with different aquifer systems, where each GRACE pixel encompasses 50-90 monitoring wells. Groundwater storage anomalies (GWSA) are derived for each pixel for the period 2002 to 2015 using the Release 05 (RL05) monthly GRACE gravity models and the Global Land Data Assimilation System (GLDAS) land-surface models (GWSAGRACE) as well as the actual field data (GWSAActual). Correlation analysis between GWSAGRACE and GWSAActual was performed using linear regression. The Pearson and Spearman methods show that the performance of GRACE is good in the region with simple aquifers; however, performance is poorer in the region with multiple aquifer systems. The study highlights the importance of incorporating the sensitivity of GRACE in estimation of groundwater storage in complex aquifer systems in future studies.

  19. 40 CFR 265.91 - Ground-water monitoring system.

    Science.gov (United States)

    2010-07-01

    ... this paragraph. (b) Separate monitoring systems for each waste management component of a facility are... which circumscribes the several waste management components. (c) All monitoring wells must be cased in a... Section 265.91 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES...

  20. A novel male sterility-fertility restoration system in plants for hybrid seed production.

    Science.gov (United States)

    Singh, Surendra Pratap; Singh, Sudhir P; Pandey, Tripti; Singh, Ram Rakshpal; Sawant, Samir V

    2015-06-15

    Hybrid seeds are used for stimulated crop production, as they harness heterosis. The achievement of complete male-sterility in the female-parent and the restored-fertility in F1-hybrids are the major bottlenecks in the commercial hybrid seed production. Here, we report a male sterility-fertility restoration system by engineering the in most nutritive anther wall layer tapetum of female and male parents. In the female parent, high-level, and stringent expression of Arabidopsis autophagy-related gene BECLIN1 was achieved in the tapetum, which altered the tapetal degeneration program, leading to male sterility. This works on our previously demonstrated expression cassette based on functional complementation of TATA-box mutant (TGTA) promoter and TATA-binding protein mutant3 (TBPm3), with modification by conjugating Long Hypocotyle in Far-Red1 fragment (HFR1(NT131)) with TBPm3 (HFR1(NT131)-TBPm3) to exercise regulatory control over it. In the male parent, tapetum-specific Constitutive photo-morphogenesis1 (COP1) was expressed. The F1 obtained by crossing these engineered parents showed decreased BECLIN1 expression, which was further completely abolished when COP1-mutant (COP1(L105A)) was used as a male parent, leading to normal tapetal development and restored fertility. The system works on COP1-HFR1 interaction and COP1-mediated degradation of TBPm3 pool (HFR1(NT131)-TBPm3). The system can be deployed for hybrid seed production in agricultural crops.

  1. The study of the interactions between groundwater and Sava River water in the Ljubljansko polje aquifer system (Slovenia)

    Science.gov (United States)

    Vrzel, Janja; Solomon, D. Kip; Blažeka, Željko; Ogrinc, Nives

    2018-01-01

    River basin aquifers are common sites for drinking water wells as bank filtration can be a cost effective pretreatment technology. A groundwater vulnerability to pollution depends on a groundwater mean residence time and on a relative contribution of river water versus local precipitation to groundwater. Environmental isotopes of oxygen and hydrogen (δ18O and δ2H), tritium (3H) and concentrations of nitrate (NO3-) were used to investigate hydrological pathways, mean residence time and interactions between surface water and groundwater in the Ljubljansko polje aquifer system in Slovenia. δ18O and δ2H values indicate a spatial variability of the influence of individual groundwater sources inside the aquifer - local precipitation and the Sava River water. Fractions of river water in groundwater depend on the depth of perforated screens in the pumping wells and their distance from the Sava River. It was estimated that groundwater at wells Kleče 11, Hrastje 3, and Hrastje 8 is mostly composed of recently infiltrated local precipitation, while the Sava River is the dominant source of groundwater at the well Jarški prod 1. Groundwater at wells Kleče 8, Kleče 12, and Jarški prod 3 contains on average between 41% and 48% of the Sava River water. The 3H and 3H/3He methods indicate short mean residence time of groundwater present at Jarški prod (2-7 years) and Hrastje (7-8 years). A small fraction (pollution.

  2. A Mamdani Adaptive Neural Fuzzy Inference System for Improvement of Groundwater Vulnerability.

    Science.gov (United States)

    Agoubi, Belgacem; Dabbaghi, Radhia; Kharroubi, Adel

    2018-01-23

    Assessing groundwater vulnerability is an important procedure for sustainable water management. Various methods have been developed for effective assessment of groundwater vulnerability and protection. However, each method has its own conditions of use and, in practice; it is difficult to return the same results for the same site. The research conceptualized and developed an improved DRASTIC method using Mamdani Adaptive Neural Fuzzy Inference System (M-ANFIS-DRASTIC). DRASTIC and M-ANFIS-DRASTIC were applied in the Jorf aquifer, southeastern Tunisia, and results were compared. Results confirm that M-ANFIS-DRASTIC combined with geostatistical tools is more powerful, generated more precise vulnerability classes with very low estimation variance. Fuzzy logic has a power to produce more realistic aquifer vulnerability assessments and introduces new ways of modeling in hydrogeology using natural human language expressed by logic rules. © 2018, National Ground Water Association.

  3. Threshold amounts of organic carbon needed to initiate reductive dechlorination in groundwater systems

    Science.gov (United States)

    Chapelle, Francis H.; Thomas, Lashun K.; Bradley, Paul M.; Rectanus, Heather V.; Widdowson, Mark A.

    2012-01-01

    Aquifer sediment and groundwater chemistry data from 15 Department of Defense facilities located throughout the United States were collected and analyzed with the goal of estimating the amount of natural organic carbon needed to initiate reductive dechlorination in groundwater systems. Aquifer sediments were analyzed for hydroxylamine and NaOH-extractable organic carbon, yielding a probable underestimate of potentially bioavailable organic carbon (PBOC). Aquifer sediments were also analyzed for total organic carbon (TOC) using an elemental combustion analyzer, yielding a probable overestimate of bioavailable carbon. Concentrations of PBOC correlated linearly with TOC with a slope near one. However, concentrations of PBOC were consistently five to ten times lower than TOC. When mean concentrations of dissolved oxygen observed at each site were plotted versus PBOC, it showed that anoxic conditions were initiated at approximately 200 mg/kg of PBOC. Similarly, the accumulation of reductive dechlorination daughter products relative to parent compounds increased at a PBOC concentration of approximately 200 mg/kg. Concentrations of total hydrolysable amino acids (THAA) in sediments also increased at approximately 200 mg/kg, and bioassays showed that sediment CO2 production correlated positively with THAA. The results of this study provide an estimate for threshold amounts of bioavailable carbon present in aquifer sediments (approximately 200 mg/kg of PBOC; approximately 1,000 to 2,000 mg/kg of TOC) needed to support reductive dechlorination in groundwater systems.

  4. Implications of Self-Potential Distribution for Groundwater Flow System in a Nonvolcanic Mountain Slope

    Directory of Open Access Journals (Sweden)

    Tada-nori Goto

    2012-01-01

    Full Text Available Self-potential (SP measurements were conducted at Mt. Tsukuba, Japan, which is a nonvolcanic mountain, to infer groundwater flow system in the mountain. Survey routes were set around the northern slope, and the reliability of observed SP anomaly was checked by using SP values along parallel survey routes; the error was almost within 10 mV. The FFT analysis of the spatial SP distribution allows us a separation of raw data into two components with shorter and longer wavelength. In the shorter (altitudinal wavelength than ∼200 meters, several positive SP peaks of more than 100 mV in magnitude are present, which indicate shallow perched water discharges along the slope. In the regional SP pattern of longer wavelength, there are two major perturbations from the general trend reflecting the topographic effect. By comparing the SP and hydrological data, the perturbation around the foothill is interpreted to be caused by heterogeneous infiltration at the ground surface. The perturbation around the summit is also interpreted to be caused by heterogeneous infiltration process, based on a simplified numerical modeling of SP. As a result, the SP pattern is well explained by groundwater flow and infiltration processes. Thus, SP data is thought to be very useful for understanding of groundwater flow system on a mountain scale.

  5. Evaluation of the long-term evolution of the groundwater system in the Mizunami area, Japan

    International Nuclear Information System (INIS)

    Mizuno, Takashi; Milodowski, Antoni E.; Iwatsuki, Teruki

    2011-01-01

    This study aimed to develop a methodology for assessing the evolution of the long-term groundwater system, using fracture-filling calcite. Fracture-filling calcite mineralization in deep (to ca. 1000 m) granitic rocks in Mizunami area, Japan, was studied. Four generations (I to IV) of calcite precipitation can be differentiated based on their paragenetic relationships, morphological and isotopic characteristics. Carbon and oxygen isotopic ratios suggest that the Calcite I is of hydrothermal origin. On the other hand, Calcite II, IV and III were precipitated from freshwater and marine water, respectively. The Mizunami Group strata (Tertiary), which overly the basement Toki granite (Cretaceous), were initially deposited in a lacustrine environment but later became marine. Lacustrine conditions were re-established during the deposition of the upper Seto Group (Quaternary). It is suggested that both of deposition of the marine upper part of the Mizunami Group and the precipitation of Calcite III were possibly related to the same transgression event. This was followed by the precipitation of Calcite IV during subsequent fresh water flushing of the earlier marine groundwater. In summary, integrated morphological, mineralogical, microchemical and isotopic analysis of multilayered calcite fracture mineralization provides valuable information to evaluate the long-term evolution of groundwater system. (author)

  6. Numerical modeling of remediation of groundwater in a wellfield of in-situ leaching of uranium by pump-and-treat system

    International Nuclear Information System (INIS)

    Lv Junwen; Shi Wenge; Yang Yong

    2006-01-01

    Based on the hydrogeological conditions at the investigated site, the coupled mathematic model about the flow and the contaminant transportation in groundwater was established. The software Visual MODflow, the most popular simulation of groundwater flow and contaminant transportation, was used to study the contaminants distribution in groundwater during pumping at different pumping rates, and to determine the pumping well arrangement and optimal pumping rate, which directs the remediation of contaminated groundwater by the pump-and-treat system. (authors)

  7. Autonomic nervous system function in chronic exogenous subclinical thyrotoxicosis and the effect of restoring euthyroidism.

    Science.gov (United States)

    Eustatia-Rutten, Carmen F A; Corssmit, Eleonora P M; Heemstra, Karen A; Smit, Johannes W A; Schoemaker, Rik C; Romijn, Johannes A; Burggraaf, Jacobus

    2008-07-01

    Knowledge on the relationship between the autonomic nervous system and subclinical hyperthyroidism is mainly based upon cross-sectional studies in heterogeneous patient populations, and the effect of restoration to euthyroidism in subclinical hyperthyroidism has not been studied. We investigated the long-term effects of exogenous subclinical hyperthyroidism on the autonomic nervous system and the potential effects of restoration of euthyroidism. This was a prospective single-blinded, placebo-controlled, randomized trial. The study was performed at a university hospital. A total of 25 patients who were on more than 10-yr TSH suppressive therapy after thyroidectomy was examined. Patients were studied at baseline and subsequently randomized to a 6-month thyroid hormone substitution regimen to obtain either euthyroidism or maintenance of the subclinical hyperthyroid state. Urinary excretion of catecholamines and heart rate variability were measured. Baseline data of the subclinical hyperthyroidism patients were compared with data obtained in patients with hyperthyroidism and controls. Urinary excretion of norepinephrine and vanillylmandelic acid was higher in the subclinical hyperthyroidism patients compared with controls and lower compared with patients with overt hyperthyroidism. Heart rate variability was lower in patients with hyperthyroidism, intermediate in subclinical hyperthyroidism patients, and highest in the healthy controls. No differences were observed after restoration of euthyroidism. Long-term exogenous subclinical hyperthyroidism has effects on the autonomic nervous system measured by heart rate variability and urinary catecholamine excretion. No differences were observed after restoration to euthyroidism. This may indicate the occurrence of irreversible changes or adaptation during long-term exposure to excess thyroid hormone that is not remedied by 6-month euthyroidism.

  8. A cost-effective system for in-situ geological arsenic adsorption from groundwater.

    Science.gov (United States)

    Shan, Huimei; Ma, Teng; Wang, Yanxin; Zhao, Jie; Han, Hongyin; Deng, Yamin; He, Xin; Dong, Yihui

    2013-11-01

    An effective and low-cost in-situ geological filtration system was developed to treat arsenic-contaminated groundwater in remote rural areas. Hangjinhouqi in western Hetao Plain of Inner Mongolia, China, where groundwater contains a high arsenic concentration, was selected as the study area. Fe-mineral and limestone widely distributed in the study area were used as filter materials. Batch and column experiments as well as field tests were performed to determine optimal filtration parameters and to evaluate the effectiveness of the technology for arsenic removal under different hydrogeochemical conditions. A mixture containing natural Fe-mineral (hematite and goethite) and limestone at a mass ratio of 2:1 was found to be the most effective for arsenic removal. The results indicated that Fe-mineral in the mixture played a major role for arsenic removal. Meanwhile, limestone buffered groundwater pH to be conducive for the optimal arsenic removal. As(III) adsorption and oxidation by iron mineral, and the formation of Ca-As(V) precipitation with Ca contributed from limestone dissolution were likely mechanisms leading to the As removal. Field demonstrations revealed that a geological filter bed filled with the proposed mineral mixture reduced groundwater arsenic concentration from 400 μg/L to below 10 μg/L. The filtration system was continuously operated for a total volume of 365,000L, which is sufficient for drinking water supplying a rural household of 5 persons for 5 years at a rate of 40 L per person per day. © 2013.

  9. New Module to Simulate Groundwater-Surface Water Interactions in Small-Scale Alluvial Aquifer System.

    Science.gov (United States)

    Flores, L.

    2017-12-01

    Streamflow depletion can occur when groundwater pumping wells lower water table elevations adjacent to a nearby stream. Being able to accurately model the severity of this process is of critical importance in semi-arid regions where groundwater-surface water interactions affect water rights and the sustainability of water resource practices. The finite-difference flow model MODFLOW is currently the standard for estimating groundwater-surface water interactions in many regions in the western United States. However, certain limitations of the model persist when highly-resolved spatial scales are used to represent the stream-aquifer system, e.g. when the size of computational grid cells is much less than the river width. In this study, an external module is developed and linked with MODFLOW that (1) allows for multiple computational grid cells over the width of the river; (2) computes streamflow and stream stage along the length of the river using the one-dimensional (1D) steady (over a stress period) shallow water equations, which allows for more accurate stream stages when normal flow cannot be assumed or a rating curve is not available; and (3) incorporates a process for computing streamflow loss when an unsaturated zone develops under the streambed. Use of the module not only provides highly-resolved estimates of streamflow depletion, but also of streambed hydraulic conductivity. The new module is applied to the stream-aquifer alluvial system along the South Platte River south of Denver, Colorado, with results tested against field-measured groundwater levels, streamflow, and streamflow depletion.

  10. GROUNDWATER PROTECTION MANAGEMENT PROGRAM DESCRIPTION.

    Energy Technology Data Exchange (ETDEWEB)

    PAQUETTE,D.E.; BENNETT,D.B.; DORSCH,W.R.; GOODE,G.A.; LEE,R.J.; KLAUS,K.; HOWE,R.F.; GEIGER,K.

    2002-05-31

    THE DEPARTMENT OF ENERGY ORDER 5400.1, GENERAL ENVIRONMENTAL PROTECTION PROGRAM, REQUIRES THE DEVELOPMENT AND IMPLEMENTATION OF A GROUNDWATER PROTECTION PROGRAM. THE BNL GROUNDWATER PROTECTION MANAGEMENT PROGRAM DESCRIPTION PROVIDES AN OVERVIEW OF HOW THE LABORATORY ENSURES THAT PLANS FOR GROUNDWATER PROTECTION, MONITORING, AND RESTORATION ARE FULLY DEFINED, INTEGRATED, AND MANAGED IN A COST EFFECTIVE MANNER THAT IS CONSISTENT WITH FEDERAL, STATE, AND LOCAL REGULATIONS.

  11. Methodology for decision making in environmental restoration after nuclear accidents: temas system (version 2.1)

    International Nuclear Information System (INIS)

    Montero, M.; Moraleda, M.; Claver, F.; Vazquez, C.; Gutierrez, J.

    2001-01-01

    TEMAS is an user-friendly decision aiding computerised system to help in the selection of the best local strategy of restoration when a post-accidental environmental contamination with long lived radionuclides (''137 Cs and ''90 Sr) must be faced TEMAS provides answer for complex scenarios on whichever place of the European Community territory ( urban agricultural and forest) with different specific levels of contamination, uses and dimensions. The initial version was the result of the TEMAS project (Techniques and Management Strategies for Environmental Restoration) supported by the EU during the 4th Framework Program. Some Aspects of the methodology are at present being improved. This document applies to the computerised version 2.1 (VAZ01). (Author)

  12. Restoration of Low-Voltage Distribution Systems with Inverter-Interfaced DG Units

    DEFF Research Database (Denmark)

    Dietmannsberger, Markus; Wang, Xiongfei; Blaabjerg, Frede

    2018-01-01

    -area voltage collapse. This paper proposes a restoration strategy from zero voltage conditions for inverter-interfaced DG under islanded conditions. In the approach, a flexible and scalable Master DG inverter concept is introduced for distributed generations, where no communication is needed and an outage......The increasing share of distributed generation (DG) offers new chances in grid restoration of low-voltage distribution grids. Instead of relying on the transmission or high- and medium-voltage levels, establishing islanding operation in low-voltage grids might be a good option after a wide...... of the Master can be balanced by other DG inverters. The control strategy ensures the tracking of nominal values of the system voltage and frequency without zero steady-state error. The influences of non-controllable DG are also taken into account in the strategy with an effective countermeasure developed...

  13. Groundwater Flow Model of Göksu Delta Coastal Aquifer System

    Science.gov (United States)

    Erdem Dokuz, Uǧur; Çelik, Mehmet; Arslan, Şebnem; Engin, Hilal

    2016-04-01

    Like many other coastal areas, Göksu Delta (Mersin-Silifke, Southern Turkey) is a preferred place for human settlement especially due to its productive farmlands and water resources. The water dependent ecosystem in Göksu delta hosts about 332 different plant species and 328 different bird species besides serving for human use. Göksu Delta has been declared as Special Environmental Protection Zone, Wildlife Protection Area, and RAMSAR Convention for Wetlands of International Importance area. Unfortunately, rising population, agricultural and industrial activities cause degradation of water resources both by means of quality and quantity. This problem also exists for other wetlands around the world. It is necessary to prepare water management plans by taking global warming issues into account to protect water resources for next generations. To achieve this, the most efficient tool is to come up with groundwater management strategies by constructing groundwater flow models. By this aim, groundwater modeling studies were carried out for Göksu Delta coastal aquifer system. As a first and most important step in all groundwater modeling studies, geological and hydrogeological settings of the study area have been investigated. Göksu Delta, like many other deltaic environments, has a complex structure because it was formed with the sediments transported by Göksu River throughout the Quaternary period and shaped throughout the transgression-regression periods. Both due to this complex structure and the lack of observation wells penetrating deep enough to give an idea of the total thickness of the delta, it was impossible to reveal out the hydrogeological setting in a correct manner. Therefore, six wells were drilled to construct the conceptual hydrogeological model of Göksu Delta coastal aquifer system. On the basis of drilling studies and slug tests that were conducted along Göksu Delta, hydrostratigraphic units of the delta system have been obtained. According to

  14. A method of groundwater quality assessment based on fuzzy network-CANFIS and geographic information system (GIS)

    Science.gov (United States)

    Gholami, V.; Khaleghi, M. R.; Sebghati, M.

    2017-11-01

    The process of water quality testing is money/time-consuming, quite important and difficult stage for routine measurements. Therefore, use of models has become commonplace in simulating water quality. In this study, the coactive neuro-fuzzy inference system (CANFIS) was used to simulate groundwater quality. Further, geographic information system (GIS) was used as the pre-processor and post-processor tool to demonstrate spatial variation of groundwater quality. All important factors were quantified and groundwater quality index (GWQI) was developed. The proposed model was trained and validated by taking a case study of Mazandaran Plain located in northern part of Iran. The factors affecting groundwater quality were the input variables for the simulation, whereas GWQI index was the output. The developed model was validated to simulate groundwater quality. Network validation was performed via comparison between the estimated and actual GWQI values. In GIS, the study area was separated to raster format in the pixel dimensions of 1 km and also by incorporation of input data layers of the Fuzzy Network-CANFIS model; the geo-referenced layers of the effective factors in groundwater quality were earned. Therefore, numeric values of each pixel with geographical coordinates were entered to the Fuzzy Network-CANFIS model and thus simulation of groundwater quality was accessed in the study area. Finally, the simulated GWQI indices using the Fuzzy Network-CANFIS model were entered into GIS, and hence groundwater quality map (raster layer) based on the results of the network simulation was earned. The study's results confirm the high efficiency of incorporation of neuro-fuzzy techniques and GIS. It is also worth noting that the general quality of the groundwater in the most studied plain is fairly low.

  15. Understanding system disturbance and ecosystem services in restored saltmarshes: Integrating physical and biogeochemical processes

    Science.gov (United States)

    Spencer, K. L.; Harvey, G. L.

    2012-06-01

    Coastal saltmarsh ecosystems occupy only a small percentage of Earth's land surface, yet contribute a wide range of ecosystem services that have significant global economic and societal value. These environments currently face significant challenges associated with climate change, sea level rise, development and water quality deterioration and are consequently the focus of a range of management schemes. Increasingly, soft engineering techniques such as managed realignment (MR) are being employed to restore and recreate these environments, driven primarily by the need for habitat (re)creation and sustainable coastal flood defence. Such restoration schemes also have the potential to provide additional ecosystem services including climate regulation and waste processing. However, these sites have frequently been physically impacted by their previous land use and there is a lack of understanding of how this 'disturbance' impacts the delivery of ecosystem services or of the complex linkages between ecological, physical and biogeochemical processes in restored systems. Through the exploration of current data this paper determines that hydrological, geomorphological and hydrodynamic functioning of restored sites may be significantly impaired with respects to natural 'undisturbed' systems and that links between morphology, sediment structure, hydrology and solute transfer are poorly understood. This has consequences for the delivery of seeds, the provision of abiotic conditions suitable for plant growth, the development of microhabitats and the cycling of nutrients/contaminants and may impact the delivery of ecosystem services including biodiversity, climate regulation and waste processing. This calls for a change in our approach to research in these environments with a need for integrated, interdisciplinary studies over a range of spatial and temporal scales incorporating both intensive and extensive research design.

  16. Evaluation of influence of splay fault growth on groundwater flow around geological disposal system

    International Nuclear Information System (INIS)

    Takai, Shizuka; Takeda, Seiji; Sakai, Ryutaro; Shimada, Taro; Munakata, Masahiro; Tanaka, Tadao

    2017-01-01

    In geological disposal, the direct effect of active faults on geological repositories is avoided at the stage of site characterization, however, uncertainty remains for the avoidance of faults derived from active faults, which are concealed deep under the ground and are difficult to detect by site investigation. In this research, the influence of the growth of undetected splay faults on a natural barrier in a geological disposal system due to the future action of faults was evaluated. We investigated examples of splay faults in Japan and set conditions for the growth of splay faults. Furthermore, we assumed a disposal site composed of sedimentary rock and made a hydrogeological model of the growth of splay faults. We carried out groundwater flow analyses, changing parameters such as the location and depth of the repository and the growth velocity of splay faults. We carried out groundwater flow analyses, changing parameters such as the location and depth of the repository and the growth velocity of splay faults. The results indicate that the main flow path from the repository is changed into an upward flow along the splay fault due to its growth and that the average velocity to the ground surface becomes one or two orders of magnitude higher than that before its growth. The results also suggest that splay fault growth leads to the possibility of the downward flow of oxidizing groundwater from the ground surface area. (author)

  17. Chemical reactions in the bedrock-groundwater system of importance for the sorption of actinides

    International Nuclear Information System (INIS)

    Beall, G.W.; Allard, B.; Krajewski, T.; O'Kelley, G.D.

    1979-01-01

    Most suggested alternatives for deep underground disposal of high-level radioactive wastes rely upon several independent barriers like resistant canister materials, waste forms of low solubility in groundwaters and the use of back-fill material of low permeability and with nuclide retaining capacity. These barriers would retard the eventual release of radionuclides from the repository into the groundwater/bedrock system. The final and the only non-engineered barrier would be the host-rock itself. It would be desirable if the rock alone would be able to retain the long-lived radionuclides coming from the waste for long enough times to allow decay to harmless activity levels before they might reach the biosphere. The biological hazards from high-level reprocessng waste as well as from unreprocessed spent uranium fuel are dominated by the actinides and their daughter products (americium, plutonium, neptunium, thorium, radium) from about three hundred years after discharge from the reactor up to millions of years. In order to allow predictions of the migration of the actinides in the ground, the chemical behavior of these elements in groundwater under environmental conditions and their interactions with geologic media must be studied in detail. In this paper, studies of the sorption of americium (trivalent) and neptunium (pentavalent under oxic conditions) on some major rock-forming minerals of igneous rocks and accessory minerals are reported

  18. Supplemental Assessment of the Y-12 Groundwater Protection Program Using Monitoring and Remediation Optimization System Software

    Energy Technology Data Exchange (ETDEWEB)

    Elvado Environmental LLC; GSI Environmental LLC

    2009-01-01

    A supplemental quantitative assessment of the Groundwater Protection Program (GWPP) at the Y-12 National Security Complex (Y-12) in Oak Ridge, TN was performed using the Monitoring and Remediation Optimization System (MAROS) software. This application was previously used as part of a similar quantitative assessment of the GWPP completed in December 2005, hereafter referenced as the 'baseline' MAROS assessment (BWXT Y-12 L.L.C. [BWXT] 2005). The MAROS software contains modules that apply statistical analysis techniques to an existing GWPP analytical database in conjunction with hydrogeologic factors, regulatory framework, and the location of potential receptors, to recommend an improved groundwater monitoring network and optimum sampling frequency for individual monitoring locations. The goal of this supplemental MAROS assessment of the Y-12 GWPP is to review and update monitoring network optimization recommendations resulting from the 2005 baseline report using data collected through December 2007. The supplemental MAROS assessment is based on the findings of the baseline MAROS assessment and includes only the groundwater sampling locations (wells and natural springs) currently granted 'Active' status in accordance with the Y-12 GWPP Monitoring Optimization Plan (MOP). The results of the baseline MAROS assessment provided technical rationale regarding the 'Active' status designations defined in the MOP (BWXT 2006). One objective of the current report is to provide a quantitative review of data collected from Active but infrequently sampled wells to confirm concentrations at these locations. This supplemental MAROS assessment does not include the extensive qualitative evaluations similar to those presented in the baseline report.

  19. Pollutants transport and distribution studies in groundwater system by nuclear, geophysics and hydrogeochemical methods

    International Nuclear Information System (INIS)

    Mohd Tadza Abdul Rahman; Daud Mohamad

    2000-01-01

    In Malaysia, the most common means of managing municipal refuse is by dumping it indiscriminately in piles on the selected open land. Leachate that is formed primarily in association with precipitation that infiltrates through the refuse normally results in the migration of leachate into underlying groundwater zone. The study of pollutant transport derived from domestic refuse and their impact on water quality in groundwater system has been performed in a selected landfill site at Gemencheh, Negeri Sembilan. The study involved the determination of flow velocity and flow direction of pollutants by nuclear techniques and a detail survey by geophysical method as well as hydrogeochemical approach as a supporting evidence of pollution occurrence. Hydrogeochemical approach involved the determination of pollutants species such as chloride and nitrate. A network of about 30 observation points had been identified and sampled. The results of the study have shown that the pollutants were concentrated at the middle of the dumping site and transported with the flow velocity between 0.2-15.4 metres per day toward northeast direction. Furthermore, the study established that the municipal or domestic landfalls are considered as one of the potential sources of groundwater pollution in Malaysia

  20. Quantification of Seepage in Groundwater Dependent Wetlands

    DEFF Research Database (Denmark)

    Johansen, Ole; Beven, Keith; Jensen, Jacob Birk

    2018-01-01

    Restoration and management of groundwater dependent wetlands require tools for quantifying the groundwater seepage process. A method for determining point estimates of the groundwater seepage based on water level observations is tested. The study is based on field data from a Danish rich fen...

  1. Fingerprinting groundwater salinity sources in the Gulf Coast Aquifer System, USA

    Science.gov (United States)

    Chowdhury, Ali H.; Scanlon, Bridget R.; Reedy, Robert C.; Young, Steve

    2018-02-01

    Understanding groundwater salinity sources in the Gulf Coast Aquifer System (GCAS) is a critical issue due to depletion of fresh groundwater and concerns for potential seawater intrusion. The study objective was to assess sources of groundwater salinity in the GCAS using ˜1,400 chemical analyses and ˜90 isotopic analyses along nine well transects in the Texas Gulf Coast, USA. Salinity increases from northeast (median total dissolved solids (TDS) 340 mg/L) to southwest (median TDS 1,160 mg/L), which inversely correlates with the precipitation distribution pattern (1,370- 600 mm/yr, respectively). Molar Cl/Br ratios (median 540-600), depleted δ2H and δ18O (-24.7‰, -4.5‰) relative to seawater (Cl/Br ˜655 and δ2H, δ18O 0‰, 0‰, respectively), and elevated 36Cl/Cl ratios (˜100), suggest precipitation enriched with marine aerosols as the dominant salinity source. Mass balance estimates suggest that marine aerosols could adequately explain salt loading over the large expanse of the GCAS. Evapotranspiration enrichment to the southwest is supported by elevated chloride concentrations in soil profiles and higher δ18O. Secondary salinity sources include dissolution of salt domes or upwelling brines from geopressured zones along growth faults, mainly near the coast in the northeast. The regional extent and large quantities of brackish water have the potential to support moderate-sized desalination plants in this location. These results have important implications for groundwater management, suggesting a current lack of regional seawater intrusion and a suitable source of relatively low TDS water for desalination.

  2. The 12-foot pressure wind tunnel restoration project model support systems

    Science.gov (United States)

    Sasaki, Glen E.

    1992-01-01

    The 12 Foot Pressure Wind Tunnel is a variable density, low turbulence wind tunnel that operates at subsonic speeds, and up to six atmospheres total pressure. The restoration of this facility is of critical importance to the future of the U.S. aerospace industry. As part of this project, several state of the art model support systems are furnished to provide an optimal balance between aerodynamic and operational efficiency parameters. Two model support systems, the Rear Strut Model Support, and the High Angle of Attack Model Support are discussed. This paper covers design parameters, constraints, development, description, and component selection.

  3. Arsenic transport in groundwater, surface water, and the hyporheic zone of a mine-influenced stream-aquifer system

    OpenAIRE

    Brown, Brendan

    2005-01-01

    We investigated the transport of dissolved arsenic in groundwater, surface water and the hyporheic zone in a stream-aquifer system influenced by an abandoned arsenopyrite mine. Mine tailing piles consisting of a host of arsenic-bearing minerals including arsenopyrite and scorodite remain adjacent to the stream and represent a continuous source of arsenic. Arsenic loads from the stream, springs, and groundwater were quantified at the study reach on nine dates from January to August 2005 and ...

  4. Computer-assisted design/computer-assisted manufacturing systems: A revolution in restorative dentistry

    Directory of Open Access Journals (Sweden)

    Arbaz Sajjad

    2016-01-01

    Full Text Available For the better part of the past 20 years, dentistry has seen the development of many new all-ceramic materials and restorative techniques fueled by the desire to capture the ever elusive esthetic perfection. This has resulted in the fusion of the latest in material science and the pen ultimate in computer-assisted design/computer-assisted manufacturing (CAD/CAM technology. This case report describes the procedure for restoring the esthetic appearance of both the left and right maxillary peg-shaped lateral incisors with a metal-free sintered finely structured feldspar ceramic material using the latest laboratory CAD/CAM system. The use of CAD/CAM technology makes it possible to produce restorations faster with precision- fit and good esthetics overcoming the errors associated with traditional ceramo-metal technology. The incorporation of this treatment modality would mean that the dentist working procedures will have to be adapted in the methods of CAD/CAM technology.

  5. Information management systems for integrating the technical data and regulatory requirements of environmental restoration activities

    International Nuclear Information System (INIS)

    Geffen, C.A.; Garrett, B.A.; Walter, M.B.

    1990-03-01

    Current environmental regulations require that comprehensive planning be conducted before remediating a hazardous waste site to characterize the nature and extent of site contamination, calculate the risk to the public, and assess the effectiveness of various remediation technologies. Remediation of Department of Energy (DOE) sites contaminated with hazardous or mixed wastes will require the effective integration of scientific and engineering data with regulatory and institutional requirements. The information management challenge presented by waste site cleanup activities goes beyond merely dealing with the large quantity of data that will be generated. The information must be stored, managed, and presented in a way that provides some consistency in approach across sites, avoids duplication of effort, and facilitates responses to requests for information from the regulators and the public. This paper provides background information on the regulatory requirements for data gathering and analysis for environmental restoration activities, and outlines the data and information management requirements for completing the pre-remediation phases of an environmental restoration project. Information management systems for integrating the regulatory and institutional requirements of the environmental restoration process with the technical data and analysis requirements are also described. 7 refs

  6. Tidal variability of nutrients in a coastal coral reef system influenced by groundwater

    Directory of Open Access Journals (Sweden)

    G. Wang

    2018-02-01

    Full Text Available To investigate variation in nitrite, nitrate, phosphate, and silicate in a spring–neap tide in a coral reef system influenced by groundwater discharge, we carried out a time-series observation of these nutrients and 228Ra, a tracer of groundwater discharge, in the Luhuitou fringing reef at Sanya Bay in the South China Sea. The maximum 228Ra, 45.3 dpm 100 L−1, appeared at low tide and the minimum, 14.0 dpm 100 L−1, appeared during a flood tide in the spring tide. The activity of 228Ra was significantly correlated with water depth and salinity in the spring–neap tide, reflecting the tidal-pumping feature of groundwater discharge. Concentrations of all nutrients exhibited strong diurnal variation, with a maximum in the amplitude of the diel change for nitrite, nitrate, phosphate, and silicate in the spring tide of 0.46, 1.54, 0.12, and 2.68 µM, respectively. Nitrate and phosphate were negatively correlated with water depth during the spring tide but showed no correlation during the neap tide. Nitrite was positively correlated with water depth in the spring and neap tide due to mixing of nitrite-depleted groundwater and nitrite-rich offshore seawater. They were also significantly correlated with salinity (R2  ≥  0.9 and P < 0.05 at the ebb flow of the spring tide, negative for nitrate and phosphate and positive for nitrite, indicating the mixing of nitrite-depleted, nitrate- and phosphate-rich less saline groundwater and nitrite-rich, nitrate- and phosphate-depleted saline offshore seawater. We quantified variation in oxidized nitrogen (NOx and phosphate contributed by biological processes based on deviations from mixing lines of these nutrients. During both the spring and neap tide biologically contributed NOx and phosphate were significantly correlated with regression slopes of 4.60 (R2  =  0.16 in the spring tide and 13.4 (R2  =  0.75 in the neap tide, similar to the composition of these

  7. Restorative neuroscience

    DEFF Research Database (Denmark)

    Andres, Robert H; Meyer, Morten; Ducray, Angélique D

    2008-01-01

    There is increasing interest in the search for therapeutic options for diseases and injuries of the central nervous system (CNS), for which currently no effective treatment strategies are available. Replacement of damaged cells and restoration of function can be accomplished by transplantation of...

  8. Columbia River System Operation Review final environmental impact statement. Appendix L: Soils, geology and groundwater

    International Nuclear Information System (INIS)

    1995-11-01

    The System Operation Review (SOR) is a study and environmental compliance process being used by the three Federal agencies to analyze future operations of the system and river use issues. The goal of the SOR is to achieve a coordinated system operation strategy for the river that better meets the needs of all river users. This technical appendix addresses only the effects of alternative system operating strategies for managing the Columbia River system. This appendix addresses the study of geology, soils, and groundwater concerns relative to the System Operation Review (SOR). Chapter 1 provides an overview of the study, scope, and process for this resource area. In order, the respective sections of this chapter discuss the relevant issues for the study, and the means by which the SOR team carried out the study

  9. The geochemistry of Don Juan Pond: Evidence for a deep groundwater flow system in Wright Valley, Antarctica

    Science.gov (United States)

    Toner, J. D.; Catling, D. C.; Sletten, R. S.

    2017-09-01

    Don Juan Pond (DJP), Antarctica, is one of the most unusual surface waters on Earth because of its CaCl2-rich composition. To investigate the evolution of pond waters during closed-basin evaporation and to understand the source of brines responsible for the chemistry of DJP, we apply a newly developed low-temperature aqueous model in the Na-K-Ca-Mg-Cl system to DJP. By modeling the closed-basin evaporation of DJP and comparing ionic ratios between DJP surface water, deep groundwater, shallow groundwater, and other surface chemistries in Wright Valley, we find that DJP is best explained by upwelling deep groundwater, as opposed to recent hypotheses proposing shallow groundwater sources. The early closed-basin evolution of brines in our model accurately predicts observed chemistries in DJP; however, late-stage closed-basin evaporation produces Mg-K-rich brines and salts that do not match the CaCl2-rich brine in DJP. Based on groundwater inflow rates to DJP, we estimate that even the most concentrated brines in DJP have undergone closed-basin evaporation for less than a year. To explain the observed lack of Mg2+ and K+ accumulation in DJP over time, and the surprisingly young age for the brines, we deduce that DJP is a localized upwelling from a regional groundwater flow-through system in which evaporated DJP brines are recycled back into the subsurface over yearly timescales. The existence of a regional groundwater flow system beneath DJP has implications for water and solute budgets in cold desert ecosystems, and may provide clues for the formation of groundwater and aqueous flows on Mars.

  10. Global depletion of groundwater resources

    NARCIS (Netherlands)

    Wada, Y.; Beek, L.P.H. van; van Kempen, C.M.; Reckman, J.W.T.M.; Vasak, S.; Bierkens, M.F.P.

    2010-01-01

    In regions with frequent water stress and large aquifer systems groundwater is often used as an additional water source. If groundwater abstraction exceeds the natural groundwater recharge for extensive areas and long times, overexploitation or persistent groundwater depletion occurs. Here we

  11. Simulation of large-scale soil water systems using groundwater data and satellite based soil moisture

    Science.gov (United States)

    Kreye, Phillip; Meon, Günter

    2016-04-01

    Complex concepts for the physically correct depiction of dominant processes in the hydrosphere are increasingly at the forefront of hydrological modelling. Many scientific issues in hydrological modelling demand for additional system variables besides a simulation of runoff only, such as groundwater recharge or soil moisture conditions. Models that include soil water simulations are either very simplified or require a high number of parameters. Against this backdrop there is a heightened demand of observations to be used to calibrate the model. A reasonable integration of groundwater data or remote sensing data in calibration procedures as well as the identifiability of physically plausible sets of parameters is subject to research in the field of hydrology. Since this data is often combined with conceptual models, the given interfaces are not suitable for such demands. Furthermore, the application of automated optimisation procedures is generally associated with conceptual models, whose (fast) computing times allow many iterations of the optimisation in an acceptable time frame. One of the main aims of this study is to reduce the discrepancy between scientific and practical applications in the field of hydrological modelling. Therefore, the soil model DYVESOM (DYnamic VEgetation SOil Model) was developed as one of the primary components of the hydrological modelling system PANTA RHEI. DYVESOMs structure provides the required interfaces for the calibrations made at runoff, satellite based soil moisture and groundwater level. The model considers spatial and temporal differentiated feedback of the development of the vegetation on the soil system. In addition, small scale heterogeneities of soil properties (subgrid-variability) are parameterized by variation of van Genuchten parameters depending on distribution functions. Different sets of parameters are operated simultaneously while interacting with each other. The developed soil model is innovative regarding concept

  12. Basin F Subregional Groundwater Model

    National Research Council Canada - National Science Library

    Mazion, Edward

    2001-01-01

    The groundwater flow system at Rocky Mountain Arsenal (RMA) is complex. To evaluate proposed remedial alternatives, interaction of the local groundwater flow system with the present contamination control systems must be understood...

  13. The Practical Application of Aqueous Geochemistry in Mapping Groundwater Flow Systems in Fractured Rock Masses

    Science.gov (United States)

    Bursey, G.; Seok, E.; Gale, J. E.

    2017-12-01

    Flow to underground mines and open pits takes place through an interconnected network of regular joints/fractures and intermediate to large scale structural features such as faults and fracture zones. Large scale features can serve either as high permeability pathways or as barriers to flow, depending on the internal characteristics of the structure. Predicting long term water quality in barrier-well systems and long-term mine water inflows over a mine life, as a mine expands, requires the use of a 3D numerical flow and transport code. The code is used to integrate the physical geometry of the fractured-rock mass with porosity, permeability, hydraulic heads, storativity and recharge data and construct a model of the flow system. Once that model has been calibrated using hydraulic head and permeability/inflow data, aqueous geochemical and isotopic data provide useful tools for validating flow-system properties, when one is able to recognize and account for the non-ideal or imperfect aspects of the sampling methods used in different mining environments. If groundwater samples are collected from discrete depths within open boreholes, water in those boreholes have the opportunity to move up or down in response to the forces that drive groundwater flow, whether they be hydraulic gradients, gas pressures, or density differences associated with variations in salinity. The use of Br/Cl ratios, for example, can be used to determine if there is active flow into, or out of, the boreholes through open discontinuities in the rock mass (i.e., short-circuiting). Natural groundwater quality can also be affected to varying degrees by mixing with drilling fluids. The combined use of inorganic chemistry and stable isotopes can be used effectively to identify dilution signals and map the dilution patterns through a range of fresh, brackish and saline water types. The stable isotopes of oxygen and hydrogen are nearly ideal natural tracers of water, but situations occur when deep

  14. Numerical simulation of the groundwater-flow system of the Kitsap Peninsula, west-central Washington

    Science.gov (United States)

    Frans, Lonna M.; Olsen, Theresa D.

    2016-05-05

    ,905 acre-ft/yr (7 percent of total simulated inflow). Simulated outflow from the model primarily was through discharge to streams, lakes, springs, seeps, and Puget Sound (594,595 acre-ft/yr; 95 percent of total simulated outflow excluding changes in storage) and through withdrawals from wells (30,761 acre-ft/yr; 5 percent of total simulated outflow excluding changes in storage).Six scenarios were formulated with input from project stakeholders and were simulated using the calibrated model to provide representative examples of how the model could be used to evaluate the effects on water levels and stream baseflows of potential changes in groundwater withdrawals, in consumptive use, and in recharge. These included simulations of a steady-state system, no-pumping and return flows, 15-percent increase in current withdrawals in all wells, 80-percent decrease in outdoor water to simulate effects of conservation efforts, 15-percent decrease in recharge from precipitation to simulate a drought, and particle tracking to determine flow paths.Changes in water-level altitudes and baseflow amounts vary depending on the stress applied to the system in these various scenarios. Reducing recharge by 15 percent between 2005 and 2012 had the largest effect, with water-level altitudes declining throughout the model domain and baseflow amounts decreasing by as much as 18 percent compared to baseline conditions. Changes in pumping volumes had a smaller effect on the model. Removing all pumping and resulting return flows caused increased water-level altitudes in many areas and increased baseflow amounts of between 1 and 3 percent.

  15. Hydrogeologic evaluation and numerical simulation of the Death Valley regional ground-water flow system, Nevada and California

    International Nuclear Information System (INIS)

    D'Agnese, F.A.; Faunt, C.C.; Turner, A.K.; Hill, M.C.

    1997-01-01

    Yucca Mountain is being studied as a potential site for a high-level radioactive waste repository. In cooperation with the U.S. Department of Energy, the U.S. Geological Survey is evaluating the geologic and hydrologic characteristics of the ground-water system. The study area covers approximately 100,000 square kilometers between lat 35 degrees N., long 115 degrees W and lat 38 degrees N., long 118 degrees W and encompasses the Death Valley regional ground-water flow system. Hydrology in the region is a result of both the and climatic conditions and the complex described as dominated by interbasinal flow and may be conceptualized as having two main components: a series of relatively shallow and localized flow paths that are superimposed on deeper regional flow paths. A significant component of the regional ground-water flow is through a thick Paleozoic carbonate rock sequence. Throughout the regional flow system, ground-water flow is probably controlled by extensive and prevalent structural features that result from regional faulting and fracturing. Hydrogeologic investigations over a large and hydrogeologically complex area impose severe demands on data management. This study utilized geographic information systems and geoscientific information systems to develop, store, manipulate, and analyze regional hydrogeologic data sets describing various components of the ground-water flow system

  16. Implications of Self-Potential Distribution for Groundwater Flow System in a Nonvolcanic Mountain Slope

    OpenAIRE

    Goto, Tada-nori; Kondo, Kazuya; Ito, Rina; Esaki, Keisuke; Oouchi, Yasuo; Abe, Yutaka; Tsujimura, Maki

    2012-01-01

    Self-potential (SP) measurements were conducted at Mt. Tsukuba, Japan, which is a nonvolcanic mountain, to infer groundwater flow system in the mountain. Survey routes were set around the northern slope, and the reliability of observed SP anomaly was checked by using SP values along parallel survey routes; the error was almost within 10 mV. The FFT analysis of the spatial SP distribution allows us a separation of raw data into two components with shorter and longer wavelength. In the shorter ...

  17. Basic concepts and formulations for isotope geochemical modelling of groundwater systems

    International Nuclear Information System (INIS)

    Kalin, R.M.

    1996-01-01

    This chapter describes the basic chemical principles and methodologies for geochemical models and their use in the field of isotope hydrology. Examples of calculation procedures are given on actual field data. Summary information on available PC software for geochemical modeling is included. The specific software, NETPATH, which can be used for chemical speciation, mass balance and isotope balance along a flow path in groundwater systems, is discussed at some length with an illustrative example of its application to field data. (author). Refs, 14 figs, 15 tabs

  18. Analysis of TCE Fate and Transport in Karst Groundwater Systems Using Statistical Mixed Models

    Science.gov (United States)

    Anaya, A. A.; Padilla, I. Y.

    2012-12-01

    Karst groundwater systems are highly productive and provide an important fresh water resource for human development and ecological integrity. Their high productivity is often associated with conduit flow and high matrix permeability. The same characteristics that make these aquifers productive also make them highly vulnerable to contamination and a likely for contaminant exposure. Of particular interest are trichloroethylene, (TCE) and Di-(2-Ethylhexyl) phthalate (DEHP). These chemicals have been identified as potential precursors of pre-term birth, a leading cause of neonatal complications with a significant health and societal cost. Both of these contaminants have been found in the karst groundwater formations in this area of the island. The general objectives of this work are to: (1) develop fundamental knowledge and determine the processes controlling the release, mobility, persistence, and possible pathways of contaminants in karst groundwater systems, and (2) characterize transport processes in conduit and diffusion-dominated flow under base flow and storm flow conditions. The work presented herein focuses on the use of geo-hydro statistical tools to characterize flow and transport processes under different flow regimes, and their application in the analysis of fate and transport of TCE. Multidimensional, laboratory-scale Geo-Hydrobed models (GHM) were used for this purpose. The models consist of stainless-steel tanks containing karstified limestone blocks collected from the karst aquifer formation of northern Puerto Rico. The models integrates a network of sampling wells to monitor flow, pressure, and solute concentrations temporally and spatially. Experimental work entails injecting dissolved CaCl2 tracers and TCE in the upstream boundary of the GHM while monitoring TCE and tracer concentrations spatially and temporally in the limestone under different groundwater flow regimes. Analysis of the temporal and spatial concentration distributions of solutes

  19. Basic concepts and formulations for isotope geochemical modelling of groundwater systems

    Energy Technology Data Exchange (ETDEWEB)

    Kalin, R M [The Queen` s University, Belfast, Northern Ireland (United Kingdom). Dept. of Civil Engineering

    1996-10-01

    This chapter describes the basic chemical principles and methodologies for geochemical models and their use in the field of isotope hydrology. Examples of calculation procedures are given on actual field data. Summary information on available PC software for geochemical modeling is included. The specific software, NETPATH, which can be used for chemical speciation, mass balance and isotope balance along a flow path in groundwater systems, is discussed at some length with an illustrative example of its application to field data. (author). Refs, 14 figs, 15 tabs.

  20. Study of groundwater vulnerability to pollution using the DRASTIC method coupled with a geographic information system (GIS): application to groundwater Beni Amir, Morocco

    Science.gov (United States)

    Knouz, Najat; Boudhar, Abdelghani; Bachaoui, El Mostafa

    2016-04-01

    Fresh water is the condition of all life on Earth for its vital role in the survival of living beings and in the social, economic and technological development. The Groundwater, as the surface water, is increasingly threatened by agricultural and industrial pollution. In this respect, the groundwater vulnerability assessment to pollution is a very valuable tool for resource protection, management of its quality and uses it in a sustainable way. The main objective of this study is the evaluation of groundwater vulnerability to pollution of the study area, Beni Amir, located in the first irrigated perimeter of Morocco, Tadla, using the DRASTIC method (depth to water, net recharge, aquifer media, soil media, Topography, impact of Vadose zone and hydraulic conductivity), and assessing the impact of each parameter on the DRASTIC vulnerability index by a sensitivity analysis. This study also highlights the role of geographic information systems (GIS) in assessing vulnerability. The Vulnerability index is calculated as the sum of product of ratings and weights assigned to each of the parameter DRASTIC. The results revealed four vulnerability classes, 7% of the study area has a high vulnerability, 31% are moderately vulnerable, 57% have a low vulnerability and 5% are of very low vulnerability.

  1. Focused groundwater discharge of phosphorus to a eutrophic seepage lake (Lake Væng, Denmark): implications for lake ecological state and restoration

    DEFF Research Database (Denmark)

    Kidmose, Jacob; Nilsson, Bertel; Engesgaard, Peter

    2013-01-01

    and borehole data. Discharge was found to be much focused and opposite to expected increase away from the shoreline. The average total phosphorus concentration in discharging groundwater sampled just beneath the lakebed was 0.162 mg TP/l and thereby well over freshwater ecological thresholds (0...... paths through the aquifer–lakebed interface either being overland flow through a seepage face, or focused in zones with very high discharge rates. In-lake springs have measured discharge of up to 7.45 m3 per m2 of lakebed per day. These findings were based on seepage meter measurements at 18 locations...

  2. An interdisciplinary approach for groundwater management in area contaminated by fluoride in East African Rift System

    Science.gov (United States)

    Da Pelo, Stefania; Melis, M. Teresa; Dessì, Francesco; Pistis, Marco; Funedda, Antonio; Oggiano, Giacomo; Carletti, Alberto; Soler Gil, Albert; Barbieri, Manuela; Pittalis, Daniele; Ghiglieri, Giorgio

    2017-04-01

    Groundwater is the main source of fresh water supply for most of the rural communities in Africa (approximately 75% of Africans has confidence in groundwater as their major source of drinking water). Many African countries has affected by high fluoride concentration in groundwater (up to 90 mg/L), generating the contamination of waters, soils and food, in particular in the eastern part of the continent. It seems that fluoride concentration is linked to geology of the Rift Valley: geogenic occurrence of fluoride is often connected to supergenic enrichment due to the weathering of alkaline volcanic rocks, fumaric gases and presence of thermal waters. The H2020 project FLOWERED (de-FLuoridation technologies for imprOving quality of WatEr and agRo-animal products along the East African Rift Valley in the context of aDaptation to climate change) wish to address environmental and health (human and animal) issues associated to the fluoride contamination in the African Rift Valley, in particular in three case study area located in Ethiopia, Tanzania and Kenya. FLOWERED aims to develop an integrated, sustainable and participative water and agriculture management at a cross-boundary catchment scale through a strong interdisciplinary research approach. It implies knowledge of geology, hydrogeology, mineralogy, geochemistry, agronomy, crop and animal sciences, engineering, technological sciences, data management and software design, economics and communication. The proposed approach is based on a detailed knowledge of the hydrogeological setting, with the identification and mapping of the specific geological conditions of water contamination and its relation with the different land uses. The East African Rift System (EARS) groundwater circulation and storage, today already poorly understood, is characterized by a complex arrangement of aquifers. It depends on the type of porosity and permeability created during and after the rock formation, and is strongly conditioned by the

  3. EnviroTRADE: An International Environmental Restoration and Waste Management Information System

    International Nuclear Information System (INIS)

    Johnson, S.W.; Harlan, C.P.; Harrington, M.W.; Bergeron, K.D.; Rehorn, A.S.

    1993-01-01

    The US Department of Energy (DOE) has collected, and will continue to collect, large amounts of information on its environmental waste sites and associated technology development efforts. This information is being gathered in a variety of formats for various purposes. Integration and delivery of this information WW benefit decision makers, waste site managers, technology developers, regulators, and the private sector. No computer system currently exists that acts as an easy-to-use computer umbrella over all of the DOE's environmental information. The EnviroTRADE Information System, currently under development for the DOE's Environmental Restoration and Waste Management's (EM's) Office of Technology Development, provides access to a wide variety of information within a single architecture. Ongoing system development is expected to result in an extensive, networked interface to EM's diverse data benefiting a variety of users. This paper discusses the present status of the EnviroTRADE Information System as well as current and future development activities

  4. The fate of ammonium-nitrogen in leachate contaminated groundwater system

    Science.gov (United States)

    M, Atta; W, Yaacob W. Z.

    2015-09-01

    Hydrogeochemical conditions influences strongly on ammonium attenuation and ultimately its long-term fate in the subsurface. The purpose of this work was to identify the conditions influencing the persistence of ammonium-nitrogen in the contaminated groundwater system of Taman Beringin ex-landfill site in Malaysia. This study applies hydrogeochemical data extractions techniques of redox sensitive groundwater species from previously installed monitoring wells between February to August 2014. Electrochemical measurements of Oxidation Reduction Potential (ORP) were collected successively with several other physicochemical parameters including pH, Temperature, and DO in the landfill site. The result show that the mean concentration of NH4-N, NO2-N, and NO3-N are: (47.98±81.83 mg/L), (0.17±0.22 mg/L) and (6.11± 8.74 mg/L) respectively. The mean range of redox potentials (-10.25±128.28 mV) delineated areas of strongly reducing conditions. Based on the evaluation of the data, NH4-N, NO2-N and NO3-N accounts for 89.98%, 0.28% and 9.7% respectively of the groundwater concentration of total nitrogen, while a miniature proportion of oxidisable nitrogen concentrations (10.02%) are attributed t o biological process of nitrification. Relationship exist between data set NH4-N and ORP (r = -0.65009). It was concluded that although biological attenuation processes are effectively decreasing the ammonia concentrations in some of the wells, the processes are inhibited by chemical conditions that were attributed to Fe reducing conditions as observed in some of the wells. NH4-N will remain persistent and at elevated levels as much as the conditions persist and contributes in determining the fate of NH4-N in the Taman Beringin ground water system.

  5. Application of Fe-Cu/Biochar System for Chlorobenzene Remediation of Groundwater in Inhomogeneous Aquifers

    Directory of Open Access Journals (Sweden)

    Xu Zhang

    2017-12-01

    Full Text Available Chlorobenzene (CB, as a typical Volatile Organic Contaminants (VOC, is toxic, highly persistent and easily migrates in water, posing a significant risk to human health and subsurface ecosystems. Therefore, exploring effective approaches to remediate groundwater contaminated by CB is essential. As an enhanced micro-electrolysis system for CB-contaminated groundwater remediation, this study attempted to couple the iron-copper bimetal with biochar. Two series of columns using sands with different grain diameters were used, consisting of iron, copper and biochar fillings as the permeable reactive barriers (PRBs, to simulate the remediation of CB-contaminated groundwater in homogeneous and heterogeneous aquifers. Regardless of the presence of homogeneous or heterogeneous porous media, the CB concentrations in the effluent from the PRB columns were significantly lower than the natural sandy columns, suggesting that the iron and copper powders coupled with biochar particles could have a significant removal effect compared to the natural sand porous media in the first columns. CB was transported relatively quickly in the heterogeneous porous media, likely due to the fact that the contaminant residence time is proportional to the infiltration velocities in the different types of porous media. The average effluent CB concentrations from the heterogeneous porous media were lower than those from homogeneous porous media. The heterogeneity retarded the vertical infiltration of CB, leading to its extended lateral distribution. During the treatment process, benzene and phenol were observed as the products of CB degradation. The ultimate CB removal efficiency was 61.4% and 68.1%, demonstrating that the simulated PRB system with the mixture of iron, copper and biochar was effective at removing CB from homogeneous and heterogeneous aquifers.

  6. A flexible hydrological warning system in Denmark for real-time surface water and groundwater simulations

    Science.gov (United States)

    He, Xin; Stisen, Simon; Wiese, Marianne B.; Jørgen Henriksen, Hans

    2015-04-01

    In Denmark, increasing focus on extreme weather events has created considerable demand for short term forecasts and early warnings in relation to groundwater and surface water flooding. The Geological Survey of Denmark and Greenland (GEUS) has setup, calibrated and applied a nationwide water resources model, the DK-Model, primarily for simulating groundwater and surface water flows and groundwater levels during the past 20 years. So far, the DK-model has only been used in offline historical and future scenario simulations. Therefore, challenges arise in operating such a model for online forecasts and early warnings, which requires access to continuously updated observed climate input data and forecast data of precipitation, temperature and global radiation for the next 48 hours or longer. GEUS has a close collaboration with the Danish Meteorological Institute in order to test and enable this data input for the DK model. Due to the comprehensive physical descriptions of the DK-Model, the simulation results can potentially be any component of the hydrological cycle within the models domain. Therefore, it is important to identify which results need to be updated and saved in the real-time mode, since it is not computationally economical to save every result considering the heavy load of data. GEUS have worked closely with the end-users and interest groups such as water planners and emergency managers from the municipalities, water supply and waste water companies, consulting companies and farmer organizations, in order to understand their possible needs for real time simulation and monitoring of the nationwide water cycle. This participatory process has been supported by a web based questionnaire survey, and a workshop that connected the model developers and the users. For qualifying the stakeholder engagement, GEUS has selected a representative catchment area (Skjern River) for testing and demonstrating a prototype of the web based hydrological warning system at the

  7. Restoration and recovery of damaged eco-epidemiological systems: application to the Salton Sea, California, USA.

    Science.gov (United States)

    Upadhyay, Ranjit Kumar; Raw, S N; Roy, P; Rai, Vikas

    2013-04-01

    In this paper, we have proposed and analysed a mathematical model to figure out possible ways to rescue a damaged eco-epidemiological system. Our strategy of rescue is based on the realization of the fact that chaotic dynamics often associated with excursions of system dynamics to extinction-sized densities. Chaotic dynamics of the model is depicted by 2D scans, bifurcation analysis, largest Lyapunov exponent and basin boundary calculations. 2D scan results show that μ, the total death rate of infected prey should be brought down in order to avoid chaotic dynamics. We have carried out linear and nonlinear stability analysis and obtained Hopf-bifurcation and persistence criteria of the proposed model system. The other outcome of this study is a suggestion which involves removal of infected fishes at regular interval of time. The estimation of timing and periodicity of the removal exercises would be decided by the nature of infection more than anything else. If this suggestion is carefully worked out and implemented, it would be most effective in restoring the health of the ecosystem which has immense ecological, economic and aesthetic potential. We discuss the implications of this result to Salton Sea, California, USA. The restoration of the Salton Sea provides a perspective for conservation and management strategy. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. A new classification system for all-ceramic and ceramic-like restorative materials.

    Science.gov (United States)

    Gracis, Stefano; Thompson, Van P; Ferencz, Jonathan L; Silva, Nelson R F A; Bonfante, Estevam A

    2015-01-01

    Classification systems for all-ceramic materials are useful for communication and educational purposes and warrant continuous revisions and updates to incorporate new materials. This article proposes a classification system for ceramic and ceramic-like restorative materials in an attempt to systematize and include a new class of materials. This new classification system categorizes ceramic restorative materials into three families: (1) glass-matrix ceramics, (2) polycrystalline ceramics, and (3) resin-matrix ceramics. Subfamilies are described in each group along with their composition, allowing for newly developed materials to be placed into the already existing main families. The criteria used to differentiate ceramic materials are based on the phase or phases present in their chemical composition. Thus, an all-ceramic material is classified according to whether a glass-matrix phase is present (glass-matrix ceramics) or absent (polycrystalline ceramics) or whether the material contains an organic matrix highly filled with ceramic particles (resin-matrix ceramics). Also presented are the manufacturers' clinical indications for the different materials and an overview of the different fabrication methods and whether they are used as framework materials or monolithic solutions. Current developments in ceramic materials not yet available to the dental market are discussed.

  9. Current Status of Groundwater Monitoring Networks in Korea

    OpenAIRE

    Jin-Yong Lee; Kideok D. Kwon

    2016-01-01

    Korea has been operating groundwater monitoring systems since 1996 as the Groundwater Act enacted in 1994 enforces nationwide monitoring. Currently, there are six main groundwater monitoring networks operated by different government ministries with different purposes: National Groundwater Monitoring Network (NGMN), Groundwater Quality Monitoring Network (GQMN), Seawater Intrusion Monitoring Network (SIMN), Rural Groundwater Monitoring Network (RGMN), Subsidiary Groundwater Monitoring Network ...

  10. Geology, selected geophysics, and hydrogeology of the White River and parts of the Great Salt Lake Desert regional groundwater flow systems, Utah and Nevada

    Science.gov (United States)

    Rowley, Peter D.; Dixon, Gary L.; Watrus , James M.; Burns, Andrews G.; Mankinen, Edward A.; McKee, Edwin H.; Pari, Keith T.; Ekren, E. Bartlett; Patrick , William G.; Comer, John B.; Inkenbrandt, Paul C.; Krahulec, K.A.; Pinnell, Michael L.

    2016-01-01

    The east-central Great Basin near the Utah-Nevada border contains two great groundwater flow systems. The first, the White River regional groundwater flow system, consists of a string of hydraulically connected hydrographic basins in Nevada spanning about 270 miles from north to south. The northernmost basin is Long Valley and the southernmost basin is the Black Mountain area, a valley bordering the Colorado River. The general regional groundwater flow direction is north to south. The second flow system, the Great Salt Lake Desert regional groundwater flow system, consists of hydrographic basins that straddle

  11. Documentation of a groundwater flow model developed to assess groundwater availability in the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to North Carolina

    Science.gov (United States)

    Masterson, John P.; Pope, Jason P.; Fienen, Michael N.; Monti, Jr., Jack; Nardi, Mark R.; Finkelstein, Jason S.

    2016-08-31

    The U.S. Geological Survey developed a groundwater flow model for the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to northeastern North Carolina as part of a detailed assessment of the groundwater availability of the area and included an evaluation of how these resources have changed over time from stresses related to human uses and climate trends. The assessment was necessary because of the substantial dependency on groundwater for agricultural, industrial, and municipal needs in this area.The three-dimensional, groundwater flow model developed for this investigation used the numerical code MODFLOW–NWT to represent changes in groundwater pumping and aquifer recharge from predevelopment (before 1900) to future conditions, from 1900 to 2058. The model was constructed using existing hydrogeologic and geospatial information to represent the aquifer system geometry, boundaries, and hydraulic properties of the 19 separate regional aquifers and confining units within the Northern Atlantic Coastal Plain aquifer system and was calibrated using an inverse modeling parameter-estimation (PEST) technique.The parameter estimation process was achieved through history matching, using observations of heads and flows for both steady-state and transient conditions. A total of 8,868 annual water-level observations from 644 wells from 1986 to 2008 were combined into 29 water-level observation groups that were chosen to focus the history matching on specific hydrogeologic units in geographic areas in which distinct geologic and hydrologic conditions were observed. In addition to absolute water-level elevations, the water-level differences between individual measurements were also included in the parameter estimation process to remove the systematic bias caused by missing hydrologic stresses prior to 1986. The total average residual of –1.7 feet was normally distributed for all head groups, indicating minimal bias. The average absolute residual value

  12. ArcNLET: A GIS-based software to simulate groundwater nitrate load from septic systems to surface water bodies

    Science.gov (United States)

    Rios, J. Fernando; Ye, Ming; Wang, Liying; Lee, Paul Z.; Davis, Hal; Hicks, Rick

    2013-03-01

    Onsite wastewater treatment systems (OWTS), or septic systems, can be a significant source of nitrates in groundwater and surface water. The adverse effects that nitrates have on human and environmental health have given rise to the need to estimate the actual or potential level of nitrate contamination. With the goal of reducing data collection and preparation costs, and decreasing the time required to produce an estimate compared to complex nitrate modeling tools, we developed the ArcGIS-based Nitrate Load Estimation Toolkit (ArcNLET) software. Leveraging the power of geographic information systems (GIS), ArcNLET is an easy-to-use software capable of simulating nitrate transport in groundwater and estimating long-term nitrate loads from groundwater to surface water bodies. Data requirements are reduced by using simplified models of groundwater flow and nitrate transport which consider nitrate attenuation mechanisms (subsurface dispersion and denitrification) as well as spatial variability in the hydraulic parameters and septic tank distribution. ArcNLET provides a spatial distribution of nitrate plumes from multiple septic systems and a load estimate to water bodies. ArcNLET's conceptual model is divided into three sub-models: a groundwater flow model, a nitrate transport and fate model, and a load estimation model which are implemented as an extension to ArcGIS. The groundwater flow model uses a map of topography in order to generate a steady-state approximation of the water table. In a validation study, this approximation was found to correlate well with a water table produced by a calibrated numerical model although it was found that the degree to which the water table resembles the topography can vary greatly across the modeling domain. The transport model uses a semi-analytical solution to estimate the distribution of nitrate within groundwater, which is then used to estimate a nitrate load using a mass balance argument. The estimates given by ArcNLET are

  13. Effects of farming systems on ground-water quality at the management systems evaluation area near Princeton, Minnesota, 1991-95

    Science.gov (United States)

    Landon, M.K.; Delin, G.N.; Lamb, J.A.; Anderson, J.L.; Dowdy, R.H.

    1998-01-01

    Ground-water quality in an unconfined sand and gravel aquifer was monitored during 1991-95 at the Minnesota Management Systems Evaluation Area (MSEA) near Princeton, Minnesota. The objectives of the study were to:

  14. Curricular Design for Intelligent Systems in Geosciences Using Urban Groundwater Studies.

    Science.gov (United States)

    Cabral-Cano, E.; Pierce, S. A.; Fuentes-Pineda, G.; Arora, R.

    2016-12-01

    Geosciences research frequently focuses on process-centered phenomena, studying combinations of physical, geological, chemical, biological, ecological, and anthropogenic factors. These interconnected Earth systems can be best understood through the use of digital tools that should be documented as workflows. To develop intelligent systems, it is important that geoscientists and computing and information sciences experts collaborate to: (1) develop a basic understanding of the geosciences and computing and information sciences disciplines so that the problem and solution approach are clear to all stakeholders, and (2) implement the desired intelligent system with a short turnaround time. However, these interactions and techniques are seldom covered in traditional Earth Sciences curricula. We have developed an exchange course on Intelligent Systems for Geosciences to support workforce development and build capacity to facilitate skill-development at the undergraduate student-level. The first version of this course was offered jointly by the University of Texas at Austin and the Universidad Nacional Autónoma de México as an intensive, study-abroad summer course. Content included: basic Linux introduction, shell scripting and high performance computing, data management, experts systems, field data collection exercises and basics of machine learning. Additionally, student teams were tasked to develop a term projects that centered on applications of Intelligent Systems applied to urban and karst groundwater systems. Projects included expert system and reusable workflow development for subsidence hazard analysis in Celaya, Mexico, a classification model to analyze land use change over a 30 Year Period in Austin, Texas, big data processing and decision support for central Texas groundwater case studies and 3D mapping with point cloud processing at three Texas field sites. We will share experiences and pedagogical insights to improve future versions of this course.

  15. An optimized groundwater extraction system for the toxic burning pits area of J-Field, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, J.J.; Johnson, R.L.; Patton, T.L.; Martino, L.E.

    1996-06-01

    Testing and disposal of chemical warfare agents, munitions, and industrial chemicals at the J-Field area of the Aberdeen Proving Ground (APG) have resulted in contamination of soil and groundwater. The discharge of contaminated groundwater to on-site marshes and adjacent estuaries poses a potential risk to ecological receptors. The Toxic Burning Pits (TBP) area is of special concern because of its disposal history. This report describes a groundwater modeling study conducted at J-Field that focused on the TBP area. The goal of this modeling effort was optimization of the groundwater extraction system at the TBP area by applying linear programming techniques. Initially, the flow field in the J-Field vicinity was characterized with a three-dimensional model that uses existing data and several numerical techniques. A user-specified border was set near the marsh and used as a constraint boundary in two modeled remediation scenarios: containment of the groundwater and containment of groundwater with an impermeable cap installed over the TBP area. In both cases, the objective was to extract the minimum amount of water necessary while satisfying the constraints. The smallest number of wells necessary was then determined for each case. This optimization approach provided two benefits: cost savings, in that the water to be treated and the well installation costs were minimized, and minimization of remediation impacts on the ecology of the marsh.

  16. Socio-hydrologic perspectives of the co-evolution of humans and groundwater in Cangzhou, North China Plain

    Science.gov (United States)

    Han, S.; Tian, F.; Liu, Y.

    2017-12-01

    This study presents a historical analysis from socio-hydrologic perspectives of the coupled human-groundwater system of the Cangzhou region in the North China Plain. The history of the "pendulum swing" for water allocation between the economic development and aquifer environmental health of the system is divided into five eras (i.e., natural, exploitation, degradation and restoration, drought-triggered deterioration, and returning to the balance). The system evolution was interpreted using the Taiji-Tire model. Over-exploitation was considered as the main cause of aquifer depletion and the groundwater utilization pattern was affected by the varying groundwater table. The aquifer depletion enhanced the community sensitivity of humans toward environmental issues, and upgraded the social productive force for restoration. The evolution of the system was substantially impacted by two droughts. The drought in 1965 induced the system from natural condition to groundwater exploiting. The drought from 1997 to 2002 resulted a pulse in further groundwater abstraction and dramatic aquifer deterioration, and the community sensitivity increased rapidly and induced the social productive force to a tipping point. From then on, the system is returning the balance through new policies and water-saving technologies. Along with the establishment of a strict water resource management strategy and the launch of the South-to-North Water Diversion Project, further restorations of groundwater environment would be implemented. However, a comprehensive and coordinated drought management plan should be devised to avoid the irreversible change of the system.

  17. Socio-hydrological perspectives of the co-evolution of humans and groundwater in Cangzhou, North China Plain

    Science.gov (United States)

    Han, Songjun; Tian, Fuqiang; Liu, Ye; Duan, Xianhui

    2017-07-01

    This paper presents a historical analysis from socio-hydrological perspectives of the coupled human-groundwater system of the Cangzhou region in the North China Plain (NCP). The history of the pendulum swing for water allocation between the economic development and aquifer environmental health of the system is divided into five eras (i.e., natural, exploitation, degradation and restoration, drought-triggered deterioration, and returning to equilibrium). The system's evolution was interpreted using the Taiji-Tire model. Over-exploitation was considered as the main cause of aquifer depletion, and the groundwater utilization pattern was affected by the varying groundwater table. The aquifer depletion enhanced community sensitivity toward environmental issues, and upgraded the social productive force for restoration. The evolution of the system was substantially impacted by two droughts. The drought in 1965 induced the system from natural conditions to groundwater exploiting. The drought from 1997 to 2002 resulted in a surge in further groundwater abstraction and dramatic aquifer deterioration, and community sensitivity increased rapidly and induced the social productive force to a tipping point. From then on, the system returns to equilibrium through new policies and water-saving technologies. Along with the establishment of a strict water resource management strategy and the launch of the South-to-North Water Diversion Project, further restoration of groundwater environment was implemented. However, a comprehensive and coordinated drought management plan should be devised to avoid irreversible change in the system.

  18. Effect of Dental Restorative Material Type and Shade on Characteristics of Two-Layer Dental Composite Systems

    Directory of Open Access Journals (Sweden)

    Atefeh Karimzadeh

    Full Text Available Abstract The purpose of this study was to investigate the effects of shade and material type and shape in dental polymer composites on the hardness and shrinkage stress of bulk and two-layered restoration systems. For this purpose, some bulk and layered specimens from three different shades of dental materials were prepared and light-cured. The experiments were carried out on three types of materials: conventional restorative composite, nanohybrid composite and nanocomposite. Micro-indentation experiment was performed on the bulk and also on each layer of layered restoration specimens using a Vicker's indenter. The interface between the two layers was studied by scanning electron microscopy (SEM. The results revealed significant differences between the values of hardness for different shades in the conventional composite and also in the nanohybrid composite. However, no statistically significant difference was observed between the hardness values for different shades in the nanocomposite samples. The layered restoration specimens of different restorative materials exhibited lower hardness values with respect to their bulk specimens. The reduction in the hardness value of the layered conventional composite samples was higher than those of the nanocomposite and nanohybrid composite specimens indicating more shrinkage stresses generated in the conventional composite restorations. According to the SEM images, a gap was observed between the two layers in the layered restorations.

  19. Advanced Control of the Dynamic Voltage Restorer for Mitigating Voltage Sags in Power Systems

    Directory of Open Access Journals (Sweden)

    Dung Vo Tien

    2018-01-01

    Full Text Available The paper presents a vector control with two cascaded loops to improve the properties of Dynamic Voltage Restorer (DVR to minimize Voltage Sags on the grid. Thereby, a vector controlled structure was built on the rotating dq-coordinate system with the combination of voltage control and the current control. The proposed DVR control method is modelled using MATLAB-Simulink. It is tested using balanced/unbalanced voltage sags as well as fluctuant and distorted voltages. As a result, by using this controlling method, the dynamic characteristics of the system have been improved significantly. The system performed with higher accuracy, faster response and lower distortion in the voltage sags compensation. The paper presents real time experimental results to verify the performance of the proposed method in real environments.

  20. Study on groundwater flow system in a sedimentary rock area. Case study for the Yoro river basin, Chiba Prefecture

    International Nuclear Information System (INIS)

    Sakai, Ryutaro; Munakata, Masahiro; Kimura, Hideo

    2007-01-01

    In the safety assessment for a geological disposal of long-lived radioactive waste such as high-level radioactive waste and TRU waste etc, it is important to estimate radionuclide migration to human society associated with groundwater flow. Groundwater flow systems for many domestic areas including Tono Mine, Kamaishi Mine and Horonobe district have been studied, but deep groundwater flow circumstances, and mixing between deep groundwater and shallow groundwater flow system are not well understood. Japan Atomic Energy Agency (JAEA) has started to investigate a sedimentary rock area in the Yoro river basin, in Chiba Prefecture, where the topographic and geological features are relatively simple for mathematical modeling, and hydraulic data as well as data from river and well water are available. Hydro-chemical conditions of the regional groundwater were discussed based on temperature, chemical compositions, isotopic ratios of hydrogen and oxygen, and the isotopic age of radioactive carbon for water samples collected from wells, rivers and springs in the Yoro river basin. It was found that the groundwater system in this basin consists of types of water: Ca-HCO 3 type water, Na-HCO 3 type water and NaCl type water. The Ca-HCO 3 type water is meteoric water cultivated several thousand years or after, the Na-HCO 3 type water is meteoric water cultivated under cold climates several to twenty thousand years ago. The NaCl type water is fossil brine water formed twenty thousand years ago. It was also observed that the Na-HCO 3 type water upwelled at the surface originates from GL-200m to -400m. This observation indicates that the Na-HCO 3 type water upwelled through the Ca-HCO 3 type water area with the both waters partially mixed. (author)

  1. Evaluation of energy consumption of treating nitrate-contaminated groundwater by bioelectrochemical systems.

    Science.gov (United States)

    Cecconet, Daniele; Zou, Shiqiang; Capodaglio, Andrea G; He, Zhen

    2018-09-15

    Nitrate contamination of groundwater is a mounting concern for drinking water production due to its healthy and ecological effects. Bioelectrochemical systems (BES) are a promising method for energy efficient nitrate removal, but its energy consumption has not been well understood. Herein, we conducted a preliminary analysis of energy consumption based on both literature information and multiple assumptions. Four scenarios were created for the purpose of analysis based on two treatment approaches, microbial fuel cells (MFCs) and controlled biocathodic denitrification (CBD), under either in situ or ex situ deployment. The results show a specific energy consumption based on the mass of NO 3 - -N removed (SEC N ) of 0.341 and 1.602 kWh kg NO 3 - -N -1 obtained from in situ and ex situ treatments with MFCs, respectively; the main contributor was the extraction of the anolyte (100%) in the former and pumping the groundwater (74.8%) for the latter. In the case of CBD treatment, the energy consumption by power supply outcompeted all the other energy items (over 85% in all cases), and a total SEC N of 19.028 and 10.003 kWh kg NO 3 - -N -1 were obtained for in situ and ex situ treatments, respectively. The increase in the water table depth (from 10 to 30 m) and the decrease of the nitrate concentration (from 25 to 15 mg NO 3 - -N) would lead to a rise in energy consumption in the ex situ treatment. Although some data might be premature due to the lack of sufficient information in available literature, the results could provide an initial picture of energy consumption by BES-based groundwater treatment and encourage further thinking and analysis of energy consumption (and production). Copyright © 2018 Elsevier B.V. All rights reserved.

  2. An Elitist Multiobjective Tabu Search for Optimal Design of Groundwater Remediation Systems.

    Science.gov (United States)

    Yang, Yun; Wu, Jianfeng; Wang, Jinguo; Zhou, Zhifang

    2017-11-01

    This study presents a new multiobjective evolutionary algorithm (MOEA), the elitist multiobjective tabu search (EMOTS), and incorporates it with MODFLOW/MT3DMS to develop a groundwater simulation-optimization (SO) framework based on modular design for optimal design of groundwater remediation systems using pump-and-treat (PAT) technique. The most notable improvement of EMOTS over the original multiple objective tabu search (MOTS) lies in the elitist strategy, selection strategy, and neighborhood move rule. The elitist strategy is to maintain all nondominated solutions within later search process for better converging to the true Pareto front. The elitism-based selection operator is modified to choose two most remote solutions from current candidate list as seed solutions to increase the diversity of searching space. Moreover, neighborhood solutions are uniformly generated using the Latin hypercube sampling (LHS) in the bounded neighborhood space around each seed solution. To demonstrate the performance of the EMOTS, we consider a synthetic groundwater remediation example. Problem formulations consist of two objective functions with continuous decision variables of pumping rates while meeting water quality requirements. Especially, sensitivity analysis is evaluated through the synthetic case for determination of optimal combination of the heuristic parameters. Furthermore, the EMOTS is successfully applied to evaluate remediation options at the field site of the Massachusetts Military Reservation (MMR) in Cape Cod, Massachusetts. With both the hypothetical and the large-scale field remediation sites, the EMOTS-based SO framework is demonstrated to outperform the original MOTS in achieving the performance metrics of optimality and diversity of nondominated frontiers with desirable stability and robustness. © 2017, National Ground Water Association.

  3. Potential for saturated ground-water system contamination at the Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Stone, R.; Ruggieri, M.R.; Rogers, L.L.; Emerson, D.O.; Buddemeier, R.W.

    1982-01-01

    A program of hydrogeologic investigation has been carried out to determine the likelihood of contaminant movement to the saturated zone from near the ground surface at Lawrence Livermore National Laboratory (LLNL). A companion survey of potential contaminant sources was also conducted at the LLNL. Water samples from selected LLNL wells were analyzed to test the water quality in the uppermost part of the saturated zone, which is from 14 to 48 m (45 to 158 ft) beneath the surface. Only nitrate and tritium were found in concentrations above natural background. In one well, the nitrate was slightly more concentrated than the drinking water limit. The nitrate source has not been found. The tritium in all ground-water samples from wells was found far less concentrated than the drinking water limit. The extent of infiltration of surface water was traced with environmental tritium. The thickness and stratigraphy of the unsaturated zone beneath the LLNL, and nearby area, was determined with specially constructed wells and boreholes. Well hydrograph analysis indicated where infiltration of surface water reached the saturated ground-water system. The investigation indicates that water infiltrating from the surface, through alluvial deposits, reaches the saturated zone along the course of Arroyo Seco, Arroyo Las Positas, and from the depression near the center of the site where seasonal water accumulates. Several potential contaminant sources were identified, and it is likely that contaminants could move from near the ground surface to the saturated zone beneath LLNL. Additional ground-water sampling and analysis will be performed and ongoing investigations will provide estimates of the speed with which potential contaminants can flow laterally in the saturated zone beneath LLNL. 34 references, 61 figures, 16 tables

  4. Developing an Approach to Prioritize River Restoration using Data Extracted from Flood Risk Information System Databases.

    Science.gov (United States)

    Vimal, S.; Tarboton, D. G.; Band, L. E.; Duncan, J. M.; Lovette, J. P.; Corzo, G.; Miles, B.

    2015-12-01

    Prioritizing river restoration requires information on river geometry. In many states in the US detailed river geometry has been collected for floodplain mapping and is available in Flood Risk Information Systems (FRIS). In particular, North Carolina has, for its 100 Counties, developed a database of numerous HEC-RAS models which are available through its Flood Risk Information System (FRIS). These models that include over 260 variables were developed and updated by numerous contractors. They contain detailed surveyed or LiDAR derived cross-sections and modeled flood extents for different extreme event return periods. In this work, over 4700 HEC-RAS models' data was integrated and upscaled to utilize detailed cross-section information and 100-year modelled flood extent information to enable river restoration prioritization for the entire state of North Carolina. We developed procedures to extract geomorphic properties such as entrenchment ratio, incision ratio, etc. from these models. Entrenchment ratio quantifies the vertical containment of rivers and thereby their vulnerability to flooding and incision ratio quantifies the depth per unit width. A map of entrenchment ratio for the whole state was derived by linking these model results to a geodatabase. A ranking of highly entrenched counties enabling prioritization for flood allowance and mitigation was obtained. The results were shared through HydroShare and web maps developed for their visualization using Google Maps Engine API.

  5. A framework for back-up and restore under the Experimental Physics and Industrial Control System

    International Nuclear Information System (INIS)

    Karonis, N.T.

    1992-12-01

    EPICS is a system that allows one to design and implement a controls system. At its foundation, i.e., the level closest to the devices being controlled, are autonomous computers, each called an Input/Output Controller or IOC. In EPICS, devices controlled by an IOC are represented by software entities called process variables. All devices are monitored/controlled by reading/writing values from/to their associated process variables. Under this schema, distributing processing over a number of IOCs and representing devices with process variables, there are a variety of ways one can view or group the information in the control system. Two of the more common groupings are by IOC (location) and by devices (function). Simply stated, the authors require a system capable of restoring the state of the machine, in their case the Advanced Photon Source, to a known desired state from somewhere in the past. To that end, they propose a framework which describes a system that periodically records and preserves the values of key process variables so that later on, those values can be written to the machine in an attempt to restore it to that same state. One of the more powerful notions that must be preserved in any system that solves this problem is the independence between the specification of what is monitored and the specification of what is written. In other words, grouping process variables for monitoring must be kept independent of the number of different ways to group process variables (e.g., by IOC, by device, etc.) when they are written

  6. Chemical evolution of deep groundwaters in granites, information acquired from natural systems

    International Nuclear Information System (INIS)

    Toulhoat, P.; Beaucaire, C.; Ouzounian, G.

    1993-01-01

    A research program has been carried out for five years, concerning a major aspect of deep radioactive waste disposals: groundwaters in the host-rock. The following items have been examined: the exact composition of confined waters, excluding those which are found in highly conductive (even deep) fractures; evolution path from surface waters to confined waters; possible influence of the repository on the composition of groundwaters; possible influence of groundwaters on the elements which could escape the repository (major elements, trace elements, radioactive elements). The following methodology is used: groundwater sampling and analysis, identification of the major phenomena controlling element concentration in groundwaters, modelling, modelling validation. (author). 11 refs., 4 figs., 3 tabs

  7. Hydrogeology and water quality of the shallow ground-water system in eastern York County, Virginia. Water resources investigation

    International Nuclear Information System (INIS)

    1993-01-01

    The report describes the hydrogeology and water quality of the shallow ground-water system in the eastern part of York County, Va. The report includes a discussion of (1) the aquifers and confining units, (2) the flow of ground water, and (3) the quality of ground water. The report is an evaluation of the shallow ground-water system and focuses on the first 200 ft of sediments below land surface. Historical water-level and water-quality data were not available for the study area; therefore, a network of observation wells was constructed for the study. Water levels were measured to provide an understanding of the flow of ground water through the multiaquifer system. Water samples were collected and analyzed for major inorganic constituents, nutrients, and metals. The report presents maps that show the regional distribution of chloride and iron concentrations. Summary statistics and graphical summaries of selected chemical constituents provide a general assessment of the ground-water quality

  8. A conceptual hydrogeologic model for the hydrogeologic framework, geochemistry, and groundwater-flow system of the Edwards-Trinity and related aquifers in the Pecos County region, Texas

    Science.gov (United States)

    Thomas, Jonathan V.; Stanton, Gregory P.; Bumgarner, Johnathan R.; Pearson, Daniel K.; Teeple, Andrew; Houston, Natalie A.; Payne, Jason; Musgrove, MaryLynn

    2013-01-01

    The Edwards-Trinity aquifer is a vital groundwater resource for agricultural, industrial, and municipal uses in the Trans-Pecos region of west Texas. A conceptual model of the hydrogeologic framework, geochemistry, and groundwater-flow system in the 4,700 square-mile study area was developed by the U.S. Geological Survey (USGS) in cooperation with the Middle Pecos Groundwater Conservation District, Pecos County, City of Fort Stockton, Brewster County, and Pecos County Water Control and Improvement District No. 1. The model was developed to gain a better understanding of the groundwater system and to establish a scientific foundation for resource-management decisions. Data and information were collected or obtained from various sources to develop the model. Lithologic information obtained from well reports and geophysical data were used to describe the hydrostratigraphy and structural features of the groundwater system, and aquifer-test data were used to estimate aquifer hydraulic properties. Groundwater-quality data were used to evaluate groundwater-flow paths, water and rock interaction, aquifer interaction, and the mixing of water from different sources. Groundwater-level data also were used to evaluate aquifer interaction as well as to develop a potentiometric-surface map, delineate regional groundwater divides, and describe regional groundwater-flow paths.

  9. Technical support to environmental restoration division for groundwater level monitoring effort at entombed Hallam Nuclear Power Facility. Final report, August 1, 1993--July 31, 1993

    International Nuclear Information System (INIS)

    1994-01-01

    This report provides an interim summary of information from a water-level monitoring program. The information was collected by the US Geological Survey (USGS) over a 6-month period. The monitoring program between the US DOE and the USGS was set up to measure water levels in 16 observation wells at the Hallam Nuclear Facility in Hallam, Nebraska. The summary of USGS data includes: (1) a description of the USGS monitoring program; (2) a description of the collection of continuous water-level data; (3) a description of the collection of monthly water-level data; (4) table of observation well number, latitude, longitude, and depth; (5) table of monthly ground-water levels data; (6) table of recorder wells, rainfall, and barometric pressure values; (7) table of recorder well, rainfall, and barometric pressure daily values; and (8) hydrographs of selected wells. 7 figs., 3 tabs

  10. Origin and distribution of saline groundwaters in the upper Miocene aquifer system, coastal Rhodope area, northeastern Greece

    Science.gov (United States)

    Petalas, C. P.; Diamantis, I. B.

    1999-06-01

    This paper describes the origins and distribution of saline groundwaters in the coastal area of Rhodope, Greece. The aquifer system includes two aquifers within coarse-grained alluvial sediments in the coastal part of the study area. Two major water-quality groups occur in the study area, namely Ca2+-rich saline groundwater and Ca2+-poor, almost fresh groundwater. The main process controlling the groundwater chemistry is the exchange of calcium and sodium between the aquifer matrix and intruding seawater. The natural salt water in the study area is probably residual water that infiltrated the aquifer system during repeated marine transgressions in late Pleistocene time. Seawater intrusion into the coastal aquifer system occurs as a result of overpumping in two seawater wedges separated vertically by a low-permeability layer. The rate of intrusion averages 0.8 m/d and is less than expected due to a decline of the aquifer's permeability at the interface with the seawater. The application of several hydrochemical techniques (Piper and Durov diagrams; Na+/Cl-, Ca2+/Cl-, Mg2+/Cl-, and Br-/Cl- molar ratios; Ca2+/Mg2+ weight ratio; and chloride concentrations), combined with field observations, may lead to a better explanation of the origin of the saline groundwater.

  11. DOE groundwater protection strategy

    International Nuclear Information System (INIS)

    Lichtman, S.

    1988-01-01

    EH is developing a DOE-wide Groundwater Quality Protection Strategy to express DOE's commitment to the protection of groundwater quality at or near its facilities. This strategy responds to a September 1986 recommendation of the General Accounting Office. It builds on EPA's August 1984 Ground-Water Protection Strategy, which establishes a classification system designed to protect groundwater according to its value and vulnerability. The purposes of DOE's strategy are to highlight groundwater protection as part of current DOE programs and future Departmental planning, to guide DOE managers in developing site-specific groundwater protection practices where DOE has discretion, and to guide DOE's approach to negotiations with EPA/states where regulatory processes apply to groundwater protection at Departmental facilities. The strategy calls for the prevention of groundwater contamination and the cleanup of groundwater commensurate with its usefulness. It would require long-term groundwater protection with reliance on physical rather than institutional control methods. The strategy provides guidance on providing long-term protection of groundwater resources; standards for new remedial actions;guidance on establishing points of compliance; requirements for establishing classification review area; and general guidance on obtaining variances, where applicable, from regulatory requirements. It also outlines management tools to implement this strategy

  12. Design and testing of a process-based groundwater vulnerability assessment (P-GWAVA) system for predicting concentrations of agrichemicals in groundwater across the United States

    Science.gov (United States)

    Barbash, Jack E; Voss, Frank D.

    2016-03-29

    Efforts to assess the likelihood of groundwater contamination from surface-derived compounds have spanned more than three decades. Relatively few of these assessments, however, have involved the use of process-based simulations of contaminant transport and fate in the subsurface, or compared the predictions from such models with measured data—especially over regional to national scales. To address this need, a process-based groundwater vulnerability assessment (P-GWAVA) system was constructed to use transport-and-fate simulations to predict the concentration of any surface-derived compound at a specified depth in the vadose zone anywhere in the conterminous United States. The system was then used to simulate the concentrations of selected agrichemicals in the vadose zone beneath agricultural areas in multiple locations across the conterminous United States. The simulated concentrations were compared with measured concentrations of the compounds detected in shallow groundwater (that is, groundwater drawn from within a depth of 6.3 ± 0.5 meters [mean ± 95 percent confidence interval] below the water table) in more than 1,400 locations across the United States. The results from these comparisons were used to select the simulation approaches that led to the closest agreement between the simulated and the measured concentrations.The P-GWAVA system uses computer simulations that account for a broader range of the hydrologic, physical, biological and chemical phenomena known to control the transport and fate of solutes in the subsurface than has been accounted for by any other vulnerability assessment over regional to national scales. Such phenomena include preferential transport and the influences of temperature, soil properties, and depth on the partitioning, transport, and transformation of pesticides in the subsurface. Published methods and detailed soil property data are used to estimate a wide range of model input parameters for each site, including surface

  13. Development of a GIS-Based Decision Support System for Diagnosis of River System Health and Restoration

    Directory of Open Access Journals (Sweden)

    Jihong Xia

    2014-10-01

    Full Text Available The development of a decision support system (DSS to inform policy making has been progressing rapidly. This paper presents a generic framework and the development steps of a decision tool prototype of geographic information systems (GIS-based decision support system of river health diagnosis (RHD-DSS. This system integrates data, calculation models, and human knowledge of river health status assessment, causal factors diagnosis, and restoration decision making to assist decision makers during river restoration and management in Zhejiang Province, China. Our RHD-DSS is composed of four main elements: the graphical user interface (GUI, the database, the model base, and the knowledge base. It has five functional components: the input module, the database management, the diagnostic indicators management, the assessment and diagnosis, and the visual result module. The system design is illustrated with particular emphasis on the development of the database, model schemas, diagnosis and analytical processing techniques, and map management design. Finally, the application of the prototype RHD-DSS is presented and implemented for Xinjiangtang River of Haining County in Zhejiang Province, China. This case study is used to demonstrate the advantages gained by the application of this system. We conclude that there is great potential for using the RHD-DSS to systematically manage river basins in order to effectively mitigate environmental issues. The proposed approach will provide river managers and designers with improved insight into river degradation conditions, thereby strengthening the assessment process and the administration of human activities in river management.

  14. Advanced Monitoring Systems Initiative Project Achievements for Environmental Restoration and Waste Management

    International Nuclear Information System (INIS)

    Hohman, E.H.; Lohrstorfer, C.L.; Venedam, R.J.; Weeks, S.J.; Fannin, C.R.

    2006-01-01

    The Advanced Monitoring Systems Initiative (AMSI) project has been in existence since 2002. In this short time period, AMSI has successfully developed, tested and/or demonstrated over 30 advanced sensors and monitoring systems for applications in environmental restoration, waste management and other areas of national interest. This presentation summarizes the AMSI project, and gives examples of recent successes. The purpose of the presentation is to make Symposium attendees aware of AMSI's capabilities and experience, for possible use in the future. Example successes include the following: - Automated hexavalent chromium (Cr(VI)) monitoring in wells alongside the Columbia River; - Atmospheric chemical sensor array for remote, real-time plume tracking; - Wireless sensor platform for long-term monitoring of subsurface moisture; - Embedded piezo-resistive micro-cantilever (EPM) units for carbon tetrachloride (CCl 4 ) and hydrogen cyanide (HCN) detection; - 'iHistorian' for efficient, real-time data management of chemical releases. (authors)

  15. Ground-water pumpage in the Willamette lowland regional aquifer system, Oregon and Washington, 1990

    Science.gov (United States)

    Collins, Charles A.; Broad, Tyson M.

    1996-01-01

    Ground-water pumpage for 1990 was estimated for an area of about 5,700 square miles in northwestern Oregon and southwestern Washington as part of the Puget-Willamette Lowland Regional Aquifer System Analysis study. The estimated total ground-water pumpage in 1990 was about 340,000 acre-feet. Ground water in the study area is pumped mainly from Quaternary sediment; lesser amounts are withdrawn from Tertiary volcanic materials. Large parts of the area are used for agriculture, and about two and one-half times as much ground water was pumped for irrigation as for either public- supply or industrial needs. Estimates of ground- water pumpage for irrigation in the central part of the Willamette Valley were generated by using image-processing techniques and Landsat Thematic Mapper data. Field data and published reports were used to estimate pumpage for irrigation in other parts of the study area. Information on public- supply and industrial pumpage was collected from Federal, State, and private organizations and individuals.

  16. Shear Bond Strength of Three Orthodontic Bonding Systems on Enamel and Restorative Materials

    Directory of Open Access Journals (Sweden)

    Andreas Hellak

    2016-01-01

    Full Text Available Objective. The aim of this in vitro study was to determine the shear bond strength (SBS and adhesive remnant index (ARI score of two self-etching no-mix adhesives (iBond™ and Scotchbond™ on different prosthetic surfaces and enamel, in comparison with the commonly used total etch system Transbond XT™. Materials and Methods. A total of 270 surfaces (1 enamel and 8 restorative surfaces, n=30 were randomly divided into three adhesive groups. In group 1 (control brackets were bonded with Transbond XT primer. In the experimental groups iBond adhesive (group 2 and Scotchbond Universal adhesive (group 3 were used. The SBS was measured using a Zwicki 1120™ testing machine. The ARI and SBS were compared statistically using the Kruskal–Wallis test (P≤0.05. Results. Significant differences in SBS and ARI were found between the control group and experimental groups. Conclusions. Transbond XT showed the highest SBS on human enamel. Scotchbond Universal on average provides the best bonding on all other types of surface (metal, composite, and porcelain, with no need for additional primers. It might therefore be helpful for simplifying bonding in orthodontic procedures on restorative materials in patients. If metal brackets have to be bonded to a metal surface, the use of a dual-curing resin is recommended.

  17. Shear Bond Strength of Three Orthodontic Bonding Systems on Enamel and Restorative Materials.

    Science.gov (United States)

    Hellak, Andreas; Ebeling, Jennifer; Schauseil, Michael; Stein, Steffen; Roggendorf, Matthias; Korbmacher-Steiner, Heike

    2016-01-01

    Objective. The aim of this in vitro study was to determine the shear bond strength (SBS) and adhesive remnant index (ARI) score of two self-etching no-mix adhesives (iBond ™ and Scotchbond ™ ) on different prosthetic surfaces and enamel, in comparison with the commonly used total etch system Transbond XT ™ . Materials and Methods . A total of 270 surfaces (1 enamel and 8 restorative surfaces, n = 30) were randomly divided into three adhesive groups. In group 1 (control) brackets were bonded with Transbond XT primer. In the experimental groups iBond adhesive (group 2) and Scotchbond Universal adhesive (group 3) were used. The SBS was measured using a Zwicki 1120 ™ testing machine. The ARI and SBS were compared statistically using the Kruskal-Wallis test ( P ≤ 0.05). Results . Significant differences in SBS and ARI were found between the control group and experimental groups. Conclusions . Transbond XT showed the highest SBS on human enamel. Scotchbond Universal on average provides the best bonding on all other types of surface (metal, composite, and porcelain), with no need for additional primers. It might therefore be helpful for simplifying bonding in orthodontic procedures on restorative materials in patients. If metal brackets have to be bonded to a metal surface, the use of a dual-curing resin is recommended.

  18. Development of a groundwater monitoring system at Horonobe Underground Research Center

    International Nuclear Information System (INIS)

    Nanjo, Isao; Amano, Yuki; Iwatsuki, Teruki; Murakami, Hiroaki; Kunimaru, Takanori; Morikawa, Keita; Hosoya, Shinichi

    2012-03-01

    Japan Atomic Energy Agency (JAEA) develops basic investigation techniques for deep geological environment around Underground Research Laboratory (URL) at Horonobe area, Japan. The observation technique of hydrochemical condition in low permeable sedimentary rock around the facility is one of R and D subjects. We report, 1) development of hydrochemical monitoring system to observe water pressure, pH, electric conductivity, dissolved oxygen, redox potential and temperature, 2) hydrochemical observation results around URL under construction. The applicability of the hydrochemical monitoring system is evaluated for low permeable sedimentary rock bearing abundant dissolved gases. The hydrochemical observation during facility construction demonstrates that pH and redox potential of groundwater almost did not changed even at hydraulic disturbed zone (water pressure decreased zone). A CD-ROM is attached as an appendix. (J.P.N.)

  19. Assessment of Effectiveness of Geologic Isolation Systems. Variable thickness transient ground-water flow model. Volume 2. Users' manual

    International Nuclear Information System (INIS)

    Reisenauer, A.E.

    1979-12-01

    A system of computer codes to aid in the preparation and evaluation of ground-water model input, as well as in the computer codes and auxillary programs developed and adapted for use in modeling major ground-water aquifers is described. The ground-water model is interactive, rather than a batch-type model. Interactive models have been demonstrated to be superior to batch in the ground-water field. For example, looking through reams of numerical lists can be avoided with the much superior graphical output forms or summary type numerical output. The system of computer codes permits the flexibility to develop rapidly the model-required data files from engineering data and geologic maps, as well as efficiently manipulating the voluminous data generated. Central to these codes is the Ground-water Model, which given the boundary value problem, produces either the steady-state or transient time plane solutions. A sizeable part of the codes available provide rapid evaluation of the results. Besides contouring the new water potentials, the model allows graphical review of streamlines of flow, travel times, and detailed comparisons of surfaces or points at designated wells. Use of the graphics scopes provide immediate, but temporary displays which can be used for evaluation of input and output and which can be reproduced easily on hard copy devices, such as a line printer, Calcomp plotter and image photographs

  20. What Drives Saline Circulation Cells in Coastal Aquifers? An Energy Balance for Density-Driven Groundwater Systems

    Science.gov (United States)

    Harvey, C. F.; Michael, H. A.

    2017-12-01

    We formulate the energy balance for coastal groundwater systems and apply it to: (1) Explain the energy driving offshore saline circulation cells, and; (2) Assess the accuracy of numerical simulations of coastal groundwater systems. The flow of fresh groundwater to the ocean is driven by the loss of potential energy as groundwater drops from the elevation of the inland watertable, where recharge occurs, to discharge at sea level. This freshwater flow creates an underlying circulation cell of seawater, drawn into coastal aquifers offshore and discharging near shore, that adds to total submarine groundwater discharge. The saline water in the circulation cell enters and exits the aquifer through the sea floor at the same hydraulic potential. Existing theory explains that the saline circulation cell is driven by mixing of fresh and saline without any additional source of potential or mechanical power. This explanation raises a basic thermodynamic question: what is the source of energy that drives the saline circulation cell? Here, we resolve this question by building upon Hubbert's conception of hydraulic potential to formulate an energy balance for density-dependent flow and salt transport through an aquifer. We show that, because local energy dissipation within the aquifer is proportional to the square of the groundwater velocity, more groundwater flow may be driven through an aquifer for a given energy input if local variations in velocity are smoothed. Our numerical simulations of coastal groundwater systems show that dispersion of salt across the fresh-saline interface spreads flow over larger volumes of the aquifer, smoothing the velocity field, and increasing total flow and submarine groundwater discharge without consuming more power. The energy balance also provides a criterion, in addition to conventional mass balances, for judging the accuracy of numerical solutions of non-linear density-dependent flow problems. Our results show that some numerical

  1. Quantifying Third-Party Impacts and Environmental Externalities from a Cap-And-Trade System for Groundwater Management

    Science.gov (United States)

    Khan, H. F.; Yang, Y. C. E.; Brown, C.

    2016-12-01

    Economic decision models, such as the cap-and-trade system, have been shown to be useful in the context of groundwater management. A uniformly applied cap-and-trade system can however result in significant spatially and temporally varying hydrogeologic impacts that reduce public welfare. Hydrological challenges associated with the cap-and-trade system for groundwater management include establishing appropriate system boundaries, setting system-wide sustainable yield and limiting third party impacts from extractions. Given these challenges, these economic models need to be supplemented with physically based hydrogeologic models that are able to represent the spatial and temporal heterogeneity in conditions across a region. This investigation assesses third-party impacts and environmental externalities resulting from a cap-and-trade system in a sub-basin of the Republican River Basin, overlying the Ogallala aquifer in the High Plains of the United States. The economic model is coupled with a calibrated physically based groundwater model. The cap-and-trade system is developed using a multi-agent system model where individual benefits of each self-interested agent are maximized subject to bounds on irrigation requirements and water use permits. We then compare the performance of the cap-and-trade system with a smart groundwater market which, in addition to a cap on total groundwater extraction, also incorporates streamflow constraints. The results quantify third-party impacts and environmental externalities resulting from uncontrolled trading. This analysis demonstrates the value added by a well-designed cap-and-trade system able to account for basin-wide heterogeneity in hydrogeologic and ecological conditions by establishing trading limits, managing inter-area transfers and setting exchange rates for permit trading.

  2. Key Challenges and Opportunities for Conjunctive Management of Surface and Groundwater in Mega-Irrigation Systems: Lower Indus, Pakistan

    Directory of Open Access Journals (Sweden)

    Frank van Steenbergen

    2015-11-01

    Full Text Available This paper focuses on the scope of conjunctive management in the Lower Indus part of the Indus Basin Irrigation System (IBIS, and the contribution this could make towards food security and socio-economic development. The total Gross Command Area (GCA of the Lower Indus is 5.92 Mha, with a cultivable command area (CCA of 5.43 Mha, most of which is in Sindh Province. There is a limited use of groundwater in Sindh (about 4.3 Billion Cubic Meter (BCM for two reasons: first, there is a large area where groundwater is saline; and second, there is a high surface irrigation supply to most of the canal commands, e.g., average annual supply to rice command is 1723 mm, close to the annual reference crop evapotranspiration for the area, while there is an additional annual rainfall of about 200 mm. These high irrigation allocations, even in areas where groundwater is fresh, create strong disincentives for farmers to use groundwater. Consequently, areas are waterlogged to the extent of 50% and 70% before and after the monsoon, respectively, which contributes to surface salinity through capillary rise. In Sindh, about 74%–80% of the available groundwater recharge is lost in the form of non-beneficial evaporation. This gives rise to low cropping intensities and yields compared to fresh groundwater areas elsewhere in the IBIS. The drought of 1999–2002 has demonstrated a reduction in waterlogging without any corresponding reduction in crop yields. Therefore, in order to efficiently meet current water requirements of all the sectors, i.e., agriculture, domestic and industrial, an ab initio level of water reallocation and efficient water management, with consideration to groundwater quality and its safe yield, in various areas are recommended. This might systematically reduce the waterlogged areas, support greater cropping intensity than is currently being practiced, and free up water for horizontal expansion, such as in the Thar Desert.

  3. Functional bacteria and process metabolism of the Denitrifying Sulfur conversion-associated Enhanced Biological Phosphorus Removal (DS-EBPR) system: An investigation by operating the system from deterioration to restoration.

    Science.gov (United States)

    Guo, Gang; Wu, Di; Hao, Tianwei; Mackey, Hamish Robert; Wei, Li; Wang, Haiguang; Chen, Guanghao

    2016-05-15

    A sulfur conversion-associated Enhanced Biological Phosphorus (P) Removal (EBPR) system is being developed to cater for the increasing needs to treat saline/brackish wastewater resulting from seawater intrusion into groundwater and sewers and frequent use of sulfate coagulants during drinking water treatment, as well as to meet the demand for eutrophication control in warm climate regions. However, the major functional bacteria and metabolism in this emerging biological nutrient removal system are still poorly understood. This study was thus designed to explore the functional microbes and metabolism in this new EBPR system by manipulating the deterioration, failure and restoration of a lab-scale system. This was achieved by changing the mixed liquor suspended solids (MLSS) concentration to monitor and evaluate the relationships among sulfur conversion (including sulfate reduction and sulfate production), P removal, variation in microbial community structures, and stoichiometric parameters. The results show that the stable Denitrifying Sulfur conversion-associated EBPR (DS-EBPR) system was enriched by sulfate-reducing bacteria (SRB) and sulfide-oxidizing bacteria (SOB). These bacteria synergistically participated in this new EBPR process, thereby inducing an appropriate level of sulfur conversion crucial for achieving a stable DS-EBPR performance, i.e. maintaining sulfur conversion intensity at 15-40 mg S/L, corresponding to an optimal sludge concentration of 6.5 g/L. This range of sulfur conversion favors microbial community competition and various energy flows from internal polymers (i.e. polysulfide or elemental sulfur (poly-S(2-)/S(0)) and poly-β-hydroxyalkanoates (PHA)) for P removal. If this range was exceeded, the system might deteriorate or even fail due to enrichment of glycogen-accumulating organisms (GAOs). Four methods of restoring the failed system were investigated: increasing the sludge concentration, lowering the salinity or doubling the COD

  4. Hydrogeologic setting, conceptual groundwater flow system, and hydrologic conditions 1995–2010 in Florida and parts of Georgia, Alabama, and South Carolina

    Science.gov (United States)

    Bellino, Jason C.; Kuniansky, Eve L.; O'Reilly, Andrew M.; Dixon, Joann F.

    2018-05-04

    The hydrogeologic setting and groundwater flow system in Florida and parts of Georgia, Alabama, and South Carolina is dominated by the highly transmissive Floridan aquifer system. This principal aquifer is a vital source of freshwater for public and domestic supply, as well as for industrial and agricultural uses throughout the southeastern United States. Population growth, increased tourism, and increased agricultural production have led to increased demand on groundwater from the Floridan aquifer system, particularly since 1950. The response of the Floridan aquifer system to these stresses often poses regional challenges for water-resource management that commonly transcend political or jurisdictional boundaries. To help water-resource managers address these regional challenges, the U.S. Geological Survey (USGS) Water Availability and Use Science Program began assessing groundwater availability of the Floridan aquifer system in 2009.The current conceptual groundwater flow system was developed for the Floridan aquifer system and adjacent systems partly on the basis of previously published USGS Regional Aquifer-System Analysis (RASA) studies, specifically many of the potentiometric maps and the modeling efforts in these studies. The Floridan aquifer system extent was divided into eight hydrogeologically distinct subregional groundwater basins delineated on the basis of the estimated predevelopment (circa 1880s) potentiometric surface: (1) Panhandle, (2) Dougherty Plain-Apalachicola, (3) Thomasville-Tallahassee, (4) Southeast Georgia-Northeast Florida-South South Carolina, (5) Suwannee, (6) West-central Florida, (7) East-central Florida, and (8) South Florida. The use of these subregions allows for a more detailed analysis of the individual basins and the groundwater flow system as a whole.The hydrologic conditions and associated groundwater budget were updated relative to previous RASA studies to include additional data collected since the 1980s and to reflect the

  5. Spatial variability of the response to climate change in regional groundwater systems -- examples from simulations in the Deschutes Basin, Oregon

    Science.gov (United States)

    Waibel, Michael S.; Gannett, Marshall W.; Chang, Heejun; Hulbe, Christina L.

    2013-01-01

    We examine the spatial variability of the response of aquifer systems to climate change in and adjacent to the Cascade Range volcanic arc in the Deschutes Basin, Oregon using downscaled global climate model projections to drive surface hydrologic process and groundwater flow models. Projected warming over the 21st century is anticipated to shift the phase of precipitation toward more rain and less snow in mountainous areas in the Pacific Northwest, resulting in smaller winter snowpack and in a shift in the timing of runoff to earlier in the year. This will be accompanied by spatially variable changes in the timing of groundwater recharge. Analysis of historic climate and hydrologic data and modeling studies show that groundwater plays a key role in determining the response of stream systems to climate change. The spatial variability in the response of groundwater systems to climate change, particularly with regard to flow-system scale, however, has generally not been addressed in the literature. Here we simulate the hydrologic response to projected future climate to show that the response of groundwater systems can vary depending on the location and spatial scale of the flow systems and their aquifer characteristics. Mean annual recharge averaged over the basin does not change significantly between the 1980s and 2080s climate periods given the ensemble of global climate models and emission scenarios evaluated. There are, however, changes in the seasonality of groundwater recharge within the basin. Simulation results show that short-flow-path groundwater systems, such as those providing baseflow to many headwater streams, will likely have substantial changes in the timing of discharge in response changes in seasonality of recharge. Regional-scale aquifer systems with flow paths on the order of many tens of kilometers, in contrast, are much less affected by changes in seasonality of recharge. Flow systems at all spatial scales, however, are likely to reflect

  6. Sustainability of groundwater supplies in the Northern Atlantic Coastal Plain aquifer system

    Science.gov (United States)

    Masterson, John P.; Pope, Jason P.

    2016-08-31

    Groundwater is the Nation’s principal reserve of freshwater. It provides about half our drinking water, is essential to food production, and facilitates business and industry in developing economic well-being. Groundwater is also an important source of water for sustaining the ecosystem health of rivers, wetlands, and estuaries throughout the country. The decreases in groundwater levels and other effects of pumping that result from large-scale development of groundwater resources have led to concerns about the future availability of groundwater to meet all our Nation’s needs. Assessments of groundwater availability provide the science and information needed by the public and decision makers to manage water resources and use them responsibly.

  7. Assessment on seasonal variation of groundwater quality of phreatic aquifers - A river basin system

    Digital Repository Service at National Institute of Oceanography (India)

    Laluraj, C.M.; Gopinath, G.

    suspended solids (TDS), fluoride and total iron content will help to identify the quality of ground water. Groundwater contamination can often have serious ill ef- fects on human health. Groundwater with low pH values can cause gastrointestinal disorders... is considered as an important parameter for irrigation and industrial purposes. Total dissolved solids help to identify the potability of groundwater. Total iron content may not have direct effects on human health but is of importance due to aesthetic reasons...

  8. Ground-water flow in the surficial aquifer system and potential movement of contaminants from selected waste-disposal sites at Cecil Field Naval Air Station, Jacksonville, Florida

    Science.gov (United States)

    Halford, K.J.

    1998-01-01

    As part of the Installation Restoration Program, Cecil Field Naval Air Station, Jacksonville, Florida, is considering remedialaction alternatives to control the possible movement of contaminants from sites that may discharge to the surface. This requires a quantifiable understanding of ground-water flow through the surficial aquifer system and how the system will respond to any future stresses. The geologic units of interest in the study area consist of sediments of Holocene to Miocene age that extend from land surface to the base of the Hawthorn Group. The hydrogeology within the study area was determined from gamma-ray and geologists? logs. Ground-water flow through the surficial aquifer system was simulated with a seven-layer, finite-difference model that extended vertically from the water table to the top of the Upper Floridan aquifer. Results from the calibrated model were based on a long-term recharge rate of 6 inches per year, which fell in the range of 4 to 10 inches per year, estimated using stream hydrograph separation methods. More than 80 percent of ground-water flow circulates within the surficial-sand aquifer, which indicates that most contaminant movement also can be expected to move through the surficial-sand aquifer alone. The surficial-sand aquifer is the uppermost unit of the surficial aquifer system. Particle-tracking results showed that the distances of most flow paths were 1,500 feet or less from a given site to its discharge point. For an assumed effective porosity of 20 percent, typical traveltimes are 40 years or less. At all of the sites investigated, particles released 10 feet below the water table had shorter traveltimes than those released 40 feet below the water table. Traveltimes from contaminated sites to their point of discharge ranged from 2 to 300 years. The contributing areas of the domestic supply wells are not very extensive. The shortest traveltimes for particles to reach the domestic supply wells from their respective

  9. Effects of 1992 farming systems on ground-water quality at the management systems evaluation area near Princeton, Minnesota

    Science.gov (United States)

    Delin, G.N.; Landon, M.K.; Lamb, J.A.; Dowdy, R.H.

    1995-01-01

    The Management Systems Evaluation Area (MSEA) program was a multiscale, interagency initiative to evaluate the effects of agricultural systems on water quality in the midwest corn belt. The primary objective of the Minnesota MSEA was to evaluate the effects of ridge-tillage practices in a corn and soybean farming system on ground-water quality. The 65-hectare Minnesota MSEA was located in the Anoka Sand Plain near the town of Princeton, Minnesota. Three fanning systems were evaluated: corn-soybean rotation with ridge-tillage (areas B and D), sweet corn-potato rotation (areas A and C), and field corn in consecutive years (continuous corn; area E). Water samples were collected four different times per year from a network of 22 multiport wells and 29 observation wells installed in the saturated zone beneath and adjacent to the cropped areas.

  10. Pathways of sulfate and hydrogen sulfide transformations in a BTEX- contaminated groundwater system

    DEFF Research Database (Denmark)

    Einsiedl, Florian; Anneser, B.; Griebler, C.

    2010-01-01

    in complex environmental systems. As a result, compound specific stable isotope signatures in various sulfur species were determined in a tar-oil contaminated site and were linked to the microbial community distribution in the aquifer. The goal of the study was to reach an integrated understanding of sulfur...... intermediate during abiotic oxidation of hydrogen sulphide, with the latter formed during bacterial sulfate reduction. The formed elemental sulfur may be used by the specific microbial community found in this aquifer for the oxidation of organic contaminants such as toluene. In contrast, reoxidation...... of hydrogen sulfide to sulfate by molecular oxygen may affect sulfur cycling within the transition between the unsaturated and the saturated zones and therefore attenuate concentrations of contaminants in groundwater as well....

  11. Evaluation of the groundwater Hydric resources of the Guarani Aquifer System from Municipality of Araguari, Minas Gerais Brasil

    International Nuclear Information System (INIS)

    Menegasse Velasquez, L. . E- mail: menegasse@dedalus.lcc.ufmg.br; De Carvalho Filho, C.; Costa Camargos, C. .E- mail: cacf@cdtn.br; E- mail: rena@cpd.ufmt.br

    2007-01-01

    The municipality of Araguari, with a total territorial area of 2.745.85 km2, is located in the western border of the State of Minas Gerais, Brazil, and is situated at the northeastern limit of the Guarani Aquifer System-GAS. This work intends to increase the knowledge of the quantitative potencial and of the dynamics of the GAS in the Municipality bythe development of the following technical activities: elaboration of a conceptual hydrogeologic model of the GAS in the municipality; evaluation of the groundwater recharge; evaluation of groundwater reserves and resources; hydrochemical characterization; investigacion of the provenance and dynamics of groundwater by means of the stable isotopes analysis; elaboration of a hydrogeologic mathematical model of Bauru Aquifer; and evaluation of the natural vulnerability of Bauru Aquifer to anthropic pollution

  12. TINDAK PIDANA KEKERASAN DALAM RUMAH TANGGA MENURUT SISTEM PERADILAN PIDANA DALAM PERSPEKTIF RESTORATIVE JUSTICE / The Act Of Domestic Violence In Criminal Justice System In Restorative Justice Perspective

    Directory of Open Access Journals (Sweden)

    Ridwan Mansyur

    2016-11-01

    Full Text Available Banyak penyelesaian perkara kekerasan dalam rumah tangga yang tidak memenuhi rasa keadilan, terutama bagi korban dan subordinat dalam rumah tangga. Dalam disertasi ini disampaikan hasil yaitu pertama, penyelesaian perkara kekerasan dalam rumah tangga pada kenyataannya diselesaikan melalui Undang-Undang No. 23 Tahun 2004 sebagai lex specialis. Penyelesaian kasus kekerasan dalam rumah tangga berdasarkan aturan tersebut, secara empiris lebih menekankan pada pemidanaannya, sehingga terlihat tujuan preventif, protektif, dan konsolidatif tidak terpenuhi. Kedua, penelitian ini menyimpulkan bahwa kekerasan dalam rumah tangga merupakan perkara dengan multi dimensi penyelesaian karena terdapat sisi lingkup perdata dan di sisi lain lingkup pidana. Oleh karena itu dibutuhkan suatu media di dalam sistem yang dapat mengakomodasi penyelesaian perkara tersebut, yang salah satunya adalah dengan menggunakan pendekatan restorative justice.   There are many domestic violence settlements that do not satisfy the sense of justice, especially for the victims and subordinate in the household. The dissertation results: first, the settlement of domestic violence in fact settled by Act No. 23 of 2004 as lex special. The settlements of domestic violence cases based on that rule, empirically emphasis on the criminal sanction, so that the purpose of preventive, protective and consolidative was not rise. Second, the research concluded that domestic violence is a case with the multi-dimensional settlement because there is the scope of the civil and criminal sphere on the other side. Therefore, it needs a medium in the system that can accommodate the completion of the case, which one of them is restorative justice approach.

  13. The backend design of an environmental monitoring system upon real-time prediction of groundwater level fluctuation under the hillslope.

    Science.gov (United States)

    Lin, Hsueh-Chun; Hong, Yao-Ming; Kan, Yao-Chiang

    2012-01-01

    The groundwater level represents a critical factor to evaluate hillside landslides. A monitoring system upon the real-time prediction platform with online analytical functions is important to forecast the groundwater level due to instantaneously monitored data when the heavy precipitation raises the groundwater level under the hillslope and causes instability. This study is to design the backend of an environmental monitoring system with efficient algorithms for machine learning and knowledge bank for the groundwater level fluctuation prediction. A Web-based platform upon the model-view controller-based architecture is established with technology of Web services and engineering data warehouse to support online analytical process and feedback risk assessment parameters for real-time prediction. The proposed system incorporates models of hydrological computation, machine learning, Web services, and online prediction to satisfy varieties of risk assessment requirements and approaches of hazard prevention. The rainfall data monitored from the potential landslide area at Lu-Shan, Nantou and Li-Shan, Taichung, in Taiwan, are applied to examine the system design.

  14. Current bonding systems for resin-bonded restorations and fixed partial dentures made of silver–palladium–copper–gold alloy

    Directory of Open Access Journals (Sweden)

    Hideo Matsumura

    2011-02-01

    Full Text Available This review article describes about the bonding systems for noble metal alloys, bonding techniques of restorations and fixed partial dentures (FPDs made of Ag–Pd–Cu–Au alloys, and their clinical performance. Thione monomers, 6-(4-vinylbenzyl-n-propyl amino-1,3,5-triazine-2,4-dithione (VTD, 6-methacryloyloxyhexyl-2-thiouracil-5-carboxylate (MTU-6, and 10-methacryloxydecyl 6,8-dithiooctanoate (MDDT, has been proved effective for bonding noble metal alloys. An acrylic adhesive consists of the tri-n-butylborane (TBB initiator, methyl methacrylate (MMA monomer liquid with 5% 4-methacryloyloxyethyl trimellitate anhydride (4-META, and poly(methyl methacrylate (PMMA, is being used for bonding metallic restorations to abutment surfaces. Clinical performance of restorations and FPDs made of Ag–Pd–Cu–Au alloys is overall excellent when they are seated with the currently available noble metal bonding systems.

  15. Investigation of geochemical indicators to evaluate the connection between inland and coastal groundwater systems near Kaloko-Honokōhau National Historical Park, Hawai‘i

    International Nuclear Information System (INIS)

    Tillman, Fred D; Oki, Delwyn S.; Johnson, Adam G.; Barber, Larry B.; Beisner, Kimberly R.

    2014-01-01

    Highlights: • The connection between inland and coastal aquifers near Kona, Hawai‘i is uncertain. • If connected, increased inland groundwater pumping may threaten coastal ecosystems. • Connection of inland and coastal aquifers was investigated using geochemical data. • Stable isotope results provide strong evidence of a connection between the systems. • Other geochemical data suggest a connection but are not conclusive. - Abstract: Kaloko-Honokōhau National Historical Park (KAHO) is a coastal sanctuary on the western side of the Island of Hawai‘i that was established in 1978 to preserve, interpret, and perpetuate traditional Native Hawaiian culture and activities. KAHO contains a variety of culturally and ecologically significant water resources and water-related habitat for species that have been declared as threatened or endangered by the U.S. Fish and Wildlife Service, or are candidate threatened or endangered species. These habitats are dependent on coastal unconfined groundwater in a freshwater-lens system. The coastal unconfined-groundwater system is recharged by local infiltration of rainfall but also may receive recharge from an inland groundwater system containing groundwater impounded to high altitudes. The area inland of and near KAHO is being rapidly urbanized and increased groundwater withdrawals from the inland impounded-groundwater system may affect habitat and water quality in KAHO, depending on the extent of connection between the coastal unconfined groundwater and inland impounded-groundwater. An investigation of the geochemistry of surface-water and groundwater samples in and near KAHO was performed to evaluate the presence or absence of a connection between the inland impounded- and coastal unconfined-groundwater systems in the area. Analyses of major ions, selected trace elements, rare-earth elements, and strontium-isotope ratio results from ocean, fishpond, anchialine pool, and groundwater samples were consistent with a linear

  16. Groundwater age determination using 85Kr and multiple age tracers (SF6, CFCs, and 3H to elucidate regional groundwater flow systems

    Directory of Open Access Journals (Sweden)

    Makoto Kagabu

    2017-08-01

    New hydrological insights for the region: The groundwater ages could not be estimated using CFCs or SF6, particularly in the urban areas because of artificial additions to the concentration over almost the entire study area. However, even in these regional circumstances, apparent ages of approximately 16, 36, and not less than 55 years were obtained for three locations on the A–A’ line (recharge area, discharge area, and stagnant zone of groundwater, respectively from 85Kr measurements. This trend was also supported by lumped parameter model analysis using a time series of 3H observations. In contrast, along the B–B’ line, the groundwater age of not less than 55 years at three locations, including the recharge to discharge area, where CFCs and SF6 were not detected, implies old groundwater: this is also the area in which denitrification occurs. In the C area, very young groundwater was obtained from shallow water and older groundwater was detected at greater depths, as supported by the long-term fluctuations of the NO3−–N concentration in the groundwater. The results of this study can be effectively used as a “time axis” for sustainable groundwater use and protection of groundwater quality in the study area, where groundwater accounts for almost 100% of the drinking water resources.

  17. Environmental isotope study of groundwater systems in the Republic of Djibouti

    International Nuclear Information System (INIS)

    Fontes, J.Ch.; Saliege, J.F.; Zuppi, G.M.; Pouchan, P.

    1980-01-01

    Environmental isotopes and hydrogeochemistry are being used to shed new light on the occurrence of present-day recharge and on the origin of groundwater systems in the Republic of Djibouti. Furthermore, an attempt is also being made to evaluate palaeohydrological conditions during the past 6000 years. From stable isotope data which lie along a correlation line at a slope of 8 in the diagram delta 2 H-delta 18 O, it can be concluded that recharge occurs by rapid seepage in fractured rocks without evaporation. Some waters from hot springs show an oxygen shift, indicating the occurrence of an exchange process with rocks at high temperatures. The following conclusions can be reached from tritium and 14 C content of waters. Groundwaters can be divided into two groups: one deriving from recent recharge (last five or six years) corresponding to water with rather fast circulations in fractured media; and a second group, pre-bomb recharged corresponding to water with low flow rates in porous media. Only one sample (Yoboki) seems to derive from about 10-year-old recharge. In the case of Abhe hot spring, a 14 C age of about 1200 years may be evaluated. The calcite concretions of the Abhe Lake Basin are believed to have formed as a result of the mixing of lake water (sodium-carbonate type) with groundwater (sodium-chloride, calcium-sulphate type). From the 13 C and 14 C content it appears that the dissolved carbon of present-day lake water is in, or close to, equilibrium with the atmosphere. Consequently, it is assumed that such was also the case during the whole Holocene. The 18 O content of palaeolake water, evaluated from the calcite isotopic composition with the palaeo-temperature equation, was originally more negative than the present one. This is interpreted as due to the fact that the Holocene lake was fed by large floods and that significant seepage occurred through the lake bottom with a consequent reduction of the evaporation effects. (author)

  18. 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.

  19. Anti-saturation system for surface nuclear magnetic resonance in efficient groundwater detection

    Science.gov (United States)

    Lin, Jun; Zhang, Yang; Yang, Yujing; Sun, Yong; Lin, Tingting

    2017-06-01

    Compared to other geophysical techniques, the surface nuclear magnetic resonance (SNMR) method could provide unique insights into the hydrologic properties of groundwater in the subsurface. However, the SNMR signal is in the order of nanovolts (10-9 V), and the complex environmental noise, i.e., the spike and the harmony noise (10-4 V), can reach up to 105 times the signal amplitude. Saturation of the amplifier is therefore a serious problem in current SNMR systems. In this study, we propose an anti-saturation method based on an instantaneous floating-point amplifier. The gain of a programmable amplifier is controlled by the value of the input signal. A regulating speed of 50 kS/s is thus achieved to satisfy the self-adaptive adjustment of the real-time SNMR system, which replaces the original man-made setting gain. A large dynamic range of 192.65 dB with a 24-bit high speed analog-digital converter module is then implemented. Compared to traditional SNMR instruments, whose magnification factor is fixed during the experiment, our system can effectively inhibit the distortion of the SNMR signal in both laboratory and field settings. Furthermore, an improved SNR, which is realized by the real-time SNMR system, enables the accurate inversion of the aquifer. Our study broadens the applicability of SNMR systems to use in and around developed areas.

  20. Assessment of groundwater availability in the Northern Atlantic Coastal Plain aquifer system From Long Island, New York, to North Carolina

    Science.gov (United States)

    Masterson, John P.; Pope, Jason P.; Fienen, Michael N.; Monti, Jr., Jack; Nardi, Mark R.; Finkelstein, Jason S.

    2016-08-31

    Executive SummaryThe U.S. Geological Survey began a multiyear regional assessment of groundwater availability in the Northern Atlantic Coastal Plain (NACP) aquifer system in 2010 as part of its ongoing regional assessments of groundwater availability of the principal aquifers of the Nation. The goals of this national assessment are to document effects of human activities on water levels and groundwater storage, explore climate variability effects on the regional water budget, and provide consistent and integrated information that is useful to those who use and manage the groundwater resource. As part of this nationwide assessment, the USGS evaluated available groundwater resources within the NACP aquifer system from Long Island, New York, to northeastern North Carolina.The northern Atlantic Coastal Plain physiographic province depends heavily on groundwater to meet agricultural, industrial, and municipal needs. The groundwater assessment of the NACP aquifer system included an evaluation of how water use has changed over time; this evaluation primarily used groundwater budgets and development of a numerical modeling tool to assess system responses to stresses from future human uses and climate trends.This assessment focused on multiple spatial and temporal scales to examine changes in groundwater pumping, storage, and water levels. The regional scale provides a broad view of the sources and demands on the system with time. The sub-regional scale provides an evaluation of the differing response of the aquifer system across geographic areas allowing for closer examination of the interaction between different aquifers and confining units and the changes in these interactions under pumping and recharge conditions in 2013 and hydrologic stresses as much as 45 years in the future. By focusing on multiple scales, water-resource managers may utilize this study to understand system response to changes as they affect the system as a whole.The NACP aquifer system extends from

  1. Risk mapping of NO/sub 3/-N contamination on groundwater under intensive rice-based cropping systems in the Philippines

    International Nuclear Information System (INIS)

    Pascual, C.M.; Baga, M.C.S.; Valencia, D.P.

    2005-01-01

    The groundwater resources in a 265 ha watershed of highly diversified and intensive rice-based environment was endangered to NO/sub 3/-N contamination with spatial degree of influence and temporal vulnerability risks as affected by intensive cropping systems with application of high N-fertilizer and judicious use of groundwater for irrigation. Such nitrate contamination levels are above the World Health Organization's maximum contamination level of 10 ppm for drinking water. Tree-joining, complete cluster analysis of monthly groundwater depths on observation wells revealed three distinct groups of wells differentiated by groundwater depths. Planting of nitrate catch crops such as legumes to reduce groundwater contamination and vigorous information dissemination on ill-effects of high NO/sub 3/-N, as well as groundwater recharging were considered to reduce contamination. However, the groundwater extraction for irrigation is still sustainable due to natural recharging of rainfall and hydraulic connections from surface water along rivers and creeks. The combined-use of GIS and GPS proved useful for spatial and temporal risk mapping assessment on groundwater NO/sub 3/-N vulnerability among other geo-referenced attributes of groundwater and other environmental considerations at the study site. Such systems analysis tools can be used by planners, researchers, extension workers, students and farmers for other sustainable development and environmental risk mapping, assessment, extrapolation analysis and strategic planning of sustainable development of the environment. (author)

  2. Optimizing the design of large-scale ground-coupled heat pump systems using groundwater and heat transport modeling

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, H.; Itoi, R.; Fujii, J. [Kyushu University, Fukuoka (Japan). Faculty of Engineering, Department of Earth Resources Engineering; Uchida, Y. [Geological Survey of Japan, Tsukuba (Japan)

    2005-06-01

    In order to predict the long-term performance of large-scale ground-coupled heat pump (GCHP) systems, it is necessary to take into consideration well-to-well interference, especially in the presence of groundwater flow. A mass and heat transport model was developed to simulate the behavior of this type of system in the Akita Plain, northern Japan. The model was used to investigate different operational schemes and to maximize the heat extraction rate from the GCHP system. (author)

  3. Image restoration for civil engineering structure monitoring using imaging system embedded on UAV

    Science.gov (United States)

    Vozel, Benoit; Dumoulin, Jean; Chehdi, Kacem

    2013-04-01

    Nowadays, civil engineering structures are periodically surveyed by qualified technicians (i.e. alpinist) operating visual inspection using heavy mechanical pods. This method is far to be safe, not only for civil engineering structures monitoring staff, but also for users. Due to the unceasing traffic increase, making diversions or closing lanes on bridge becomes more and more difficult. New inspection methods have to be found. One of the most promising technique is to develop inspection method using images acquired by a dedicated monitoring system operating around the civil engineering structures, without disturbing the traffic. In that context, the use of images acquired with an UAV, which fly around the structures is of particular interest. The UAV can be equipped with different vision system (digital camera, infrared sensor, video, etc.). Nonetheless, detection of small distresses on images (like cracks of 1 mm or less) depends on image quality, which is sensitive to internal parameters of the UAV (vibration modes, video exposure times, etc.) and to external parameters (turbulence, bad illumination of the scene, etc.). Though progresses were made at UAV level and at sensor level (i.e. optics), image deterioration is still an open problem. These deteriorations are mainly represented by motion blur that can be coupled with out-of-focus blur and observation noise on acquired images. In practice, deteriorations are unknown if no a priori information is available or dedicated additional instrumentation is set-up at UAV level. Image restoration processing is therefore required. This is a difficult problem [1-3] which has been intensively studied over last decades [4-12]. Image restoration can be addressed by following a blind approach or a myopic one. In both cases, it includes two processing steps that can be implemented in sequential or alternate mode. The first step carries out the identification of the blur impulse response and the second one makes use of this

  4. Towards groundwater neutral cropping systems in the Alluvial Fans of the North China Plain

    NARCIS (Netherlands)

    Oort, van P.A.J.; Wang, G.; Vos, J.; Meinke, H.; Li, B.G.; Huang, J.K.; Werf, van der W.

    2016-01-01

    Groundwater levels in the North China Plain (NCP), the bread basket of China, have dropped more than one meter per year over the last 40 years, putting at risk the long term productivity of this region. Groundwater decline is most severe in the Alluvial Fans where our study site is located.

  5. Oxygen, hydrogen, and helium isotopes for investigating groundwater systems of the Cape Verde Islands, West Africa

    Science.gov (United States)

    Heilweil, V.M.; Solomon, K.D.; Gingerich, S.B.; Verstraeten, Ingrid M.

    2009-01-01

    Stable isotopes (??18O, ??2H), tritium (3H), and helium isotopes (3He, 4He) were used for evaluating groundwater recharge sources, flow paths, and residence times of three watersheds in the Cape Verde Islands (West Africa). Stable isotopes indicate the predominance of high-elevation precipitation that undergoes little evaporation prior to groundwater recharge. In contrast to other active oceanic hotspots, environmental tracers show that deep geothermal circulation does not strongly affect groundwater. Low tritium concentrations at seven groundwater sites indicate groundwater residence times of more than 50 years. Higher tritium values at other sites suggest some recent recharge. High 4He and 3He/4He ratios precluded 3H/3He dating at six sites. These high 3He/4He ratios (R/Ra values of up to 8.3) are consistent with reported mantle derived helium of oceanic island basalts in Cape Verde and provided end-member constraints for improved dating at seven other locations. Tritium and 3H/3He dating shows that S??o Nicolau Island's Ribeira Faj?? Basin has groundwater residence times of more than 50 years, whereas Fogo Island's Mosteiros Basin and Santo Ant??o Island's Ribeira Paul Basin contain a mixture of young and old groundwater. Young ages at selected sites within these two basins indicate local recharge and potential groundwater susceptibility to surface contamination and/or salt-water intrusion. ?? Springer-Verlag 2009.

  6. Appraising options to reduce shallow groundwater tables and enhance flow conditions over regional scales in an irrigated alluvial aquifer system

    Science.gov (United States)

    Morway, Eric D.; Gates, Timothy K.; Niswonger, Richard G.

    2013-01-01

    Some of the world’s key agricultural production systems face big challenges to both water quantity and quality due to shallow groundwater that results from long-term intensive irrigation, namely waterlogging and salinity, water losses, and environmental problems. This paper focuses on water quantity issues, presenting finite-difference groundwater models developed to describe shallow water table levels, non-beneficial groundwater consumptive use, and return flows to streams across two regions within an irrigated alluvial river valley in southeastern Colorado, USA. The models are calibrated and applied to simulate current baseline conditions in the alluvial aquifer system and to examine actions for potentially improving these conditions. The models provide a detailed description of regional-scale subsurface unsaturated and saturated flow processes, thereby enabling detailed spatiotemporal description of groundwater levels, recharge to infiltration ratios, partitioning of ET originating from the unsaturated and saturated zones, and groundwater flows, among other variables. Hybrid automated and manual calibration of the models is achieved using extensive observations of groundwater hydraulic head, groundwater return flow to streams, aquifer stratigraphy, canal seepage, total evapotranspiration, the portion of evapotranspiration supplied by upflux from the shallow water table, and irrigation flows. Baseline results from the two regional-scale models are compared to model predictions under variations of four alternative management schemes: (1) reduced seepage from earthen canals, (2) reduced irrigation applications, (3) rotational lease fallowing (irrigation water leased to municipalities, resulting in temporary dry-up of fields), and (4) combinations of these. The potential for increasing the average water table depth by up to 1.1 and 0.7 m in the two respective modeled regions, thereby reducing the threat of waterlogging and lowering non-beneficial consumptive use

  7. Restoring oak ecosystems on national forest system lands in the eastern region: an adaptive management approach

    Science.gov (United States)

    Gregory Nowacki; Michael Ablutz; Dan Yaussy; Thomas Schuler; Dan Dey

    2009-01-01

    The U.S. Forest Service has recently completed an ecosystem restoration framework and enacted accompanying policy to help guide its nationwide efforts. The Eastern Region is in the midst of translating the general guidance set forth in these documents to actual on-the-ground restoration. We envision a set of coordinated field demonstrations that will initially focus on...

  8. Concentrations of hormones, pharmaceuticals and other micropollutants in groundwater affected by septic systems in New England and New York

    Science.gov (United States)

    Phillips, Patrick J.; Schubert, Christopher E.; Argue, Denise M.; Fisher, Irene J.; Furlong, Edward T.; Foreman, William T.; Gray, James L.; Chalmers, Ann T.

    2015-01-01

    Septic-system discharges can be an important source of micropollutants (including pharmaceuticals and endocrine active compounds) to adjacent groundwater and surface water systems. Groundwater samples were collected from well networks tapping glacial till in New England (NE) and sandy surficial aquifer New York (NY) during one sampling round in 2011. The NE network assesses the effect of a single large septic system that receives discharge from an extended health care facility for the elderly. The NY network assesses the effect of many small septic systems used seasonally on a densely populated portion of Fire Island. The data collected from these two networks indicate that hydrogeologic and demographic factors affect micropollutant concentrations in these systems.

  9. Effects of past and future groundwater development on the hydrologic system of Verde Valley, Arizona

    Science.gov (United States)

    Garner, Bradley D.; Pool, D.R.

    2013-01-01

    Communities in central Arizona’s Verde Valley must manage limited water supplies in the face of rapidly growing populations. Developing groundwater resources to meet human needs has raised questions about the effects of groundwater withdrawals by pumping on the area’s rivers and streams, particularly the Verde River. U.S. Geological Survey hydrologists used a regional groundwater flow model to simulate the effects of groundwater pumping on streamflow in the Verde River. The study found that streamflow in the Verde River between 1910 and 2005 had been reduced as the result of streamflow depletion by groundwater pumping, also known as capture. Additionally, using three hypothetical scenarios for a period from 2005 to 2110, the study’s findings suggest that streamflow reductions will continue and may increase in the future.

  10. Heterogeneous redox reactions in groundwater flow systems - Investigation and application of two different coupled codes

    Energy Technology Data Exchange (ETDEWEB)

    Pfingsten, W.; Carnahan, C.L. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1995-05-01

    Two simulators of reactive chemical transport are applied to a set of problems involving heterogeneous reactions of uranium species. The simulators use similar algorithms to compute the heterogeneous chemical equilibria, but they use different approaches to the computation of solute transport and to the coupling of transport with chemical reactions. One simulator (MCOTAC) sequentially couples calculations of static chemical equilibria to a random-walk simulation of solute advection and dispersion. The other simulator (THCC) directly couples mass action relations for chemical equilibria to finite-difference representations of the solute transport equations. The aim of the comparison was to demonstrate the applicability of the newly developed code MCOTAC to redox problems, and to identify and investigate general differences between the two types of codes within these applications. The chosen heterogeneous redox systems are hypothetically generate systems which provide numerical difficulties within the coupled code calculation. Uranium, an important component of heterogeneous redox systems consisting of uraniferous solids and natural groundwaters, was chosen as a main component in the example redox systems because of practical interest for performance assessment of geological repositories for nuclear wastes. The calculations show reasonable agreement, in general, between the two computational approaches. Specific areas of disagreement arise from numerical difficulties to each approach. Such `benchmarking` can enhance confidence in the overall performance of individual simulators while identifying aspects that may require further investigations and possible modifications. (author) figs., tabs., 7 refs.

  11. Comparative evaluation of microleakage of composite restorations using fifth and seventh generations of adhesive systems

    Directory of Open Access Journals (Sweden)

    Mitra Tabari

    2014-09-01

    Full Text Available Introduction: Simultaneous etching of enamel and dentin using the novel generation of adhesive systems with contracted operational steps, has shown a good clinical efficacy. The aim of this study was to evaluate the microleakage of composite restorations using the V and VII generations of adhesive systems on primary teeth. Methods: This study was performed on 45 human intact extracted primary teeth. Following class V cavity preparation, the samples were randomly divided into three groups included 15 teeth based on the type of bonding agent Single Bond 2, Clearfil S3 Bond or G Bond. After applying the bonding agents, the teeth filled with composite Z250. The microleakage values of incisal and gingival margins were separately scored by 2% basic fuchsine staining based on a 0-3 ordinal ranking system. The data were analyzed by using Kruskal Wallis and Mann_whitney U tests. Results: In overall, the score of microleakage at incisal (0.58±0.94 and gingival (1.06±0.19 edges did not have significant difference. Also, there was no significant difference between incisal and gingival microleakage considering the different types of bonding. Conclusion: Regarding to less operational steps and lower risk of salivary contamination, the VII generation of dentin bonding agents can be applied for filling the class V cavities of primary teeth.

  12. Simulating the reactive transport of nitrogen species in a regional irrigated agricultural groundwater system

    Science.gov (United States)

    Bailey, R. T.; Gates, T. K.

    2011-12-01

    The fate and transport of nitrogen (N) species in irrigated agricultural groundwater systems is governed by irrigation patterns, cultivation practices, aquifer-surface water exchanges, and chemical reactions such as oxidation-reduction, volatilization, and sorption, as well as the presence of dissolved oxygen (O2). We present results of applying the newly-developed numerical model RT3D-AG to a 50,400-ha regional study site within the Lower Arkansas River Valley in southeastern Colorado, where elevated concentrations of NO3 have been observed in both groundwater and surface water during the recent decade. Furthermore, NO3 has a strong influence on the fate and transport of other contaminants in the aquifer system such as selenium (Se) through inhibition of reduction of dissolved Se as well as oxidation of precipitate Se from outcropped and bedrock shale. RT3D-AG, developed by appending the multi-species reactive transport finite-difference model RT3D with modular packages that account for variably-saturated transport, the cycling of carbon (C) and N, and the fate and transport of O2 within the soil and aquifer system, simulates organic C and organic N decomposition and mineralization, oxidation-reduction reactions, and sorption. System sources/sinks consist of applied fertilizer and manure; crop uptake of ammonium (NH4) and NO3 during the growing season; mass of O2, NO3, and NH4 associated with irrigation water and canal seepage; mass of O2, NO3, and NH4 transferred to canals and the Arkansas River from the aquifer; and dead root mass and after-harvest stover mass incorporated into the soil organic matter at the end of the growing season. Chemical reactions are simulated using first-order Monod kinetics, wherein the rate of reaction is dependent on the concentration of the reactants as well as temperature and water content of the soil. Fertilizer and manure application timing and loading, mass of seasonal crop uptake, and end-of-season root mass and stover mass are

  13. Environmental isotope study related to groundwater age, flow system and saline water origin in Quaternary aquifers of North China Plain

    International Nuclear Information System (INIS)

    Zhang Zhigan; Payne, B.R.

    1988-01-01

    An isotopic hydrology section across the North China Plain has been studied to investigate problems of groundwater age, flow system and saline water origin in a semi-arid pre-mountain artesian basin. Two local and one regional flow system along the section have been recognized. Turnover time of water for alluvial fan, shallow and regional systems are estimated to be the order of 10 2 , 10 3 , and 10 4 years respectively. Specific flow rates for the three systems have been calculated. Only less than 5 percent of flow from alluvial fan is drained by the regional flow system and the rest, in natural conditions, discharges at surface in the front edge of an alluvial fan and forms a groundwater discharge belt at a good distance away from the mountain foot. Developed in the alluvial plain and coastal plain areas the shallow flow system embraces a series of small local systems. Groundwater in these systems appears to be the salt carrier during continental salinization. It washes salt out of the recharge area and deep-occurred strata by circulating and carries it up to the surface in lowland areas. Consequently, in parallel with salinization at surface a desalinization process occurs at depth, which provides an additional explanation for the existing thick deep fresh water zone in most arid and semi-arid regions, where continental salting process is in progress. (author). 6 refs, 8 figs, 4 tabs

  14. Kansas City plant ultraviolet/ozone/hydrogen peroxide groundwater treatment system overview

    International Nuclear Information System (INIS)

    Stites, M.E.; Hughes, R.F.

    1992-01-01

    The Kansas City Plant (KCP) has committed to the utilization of a groundwater treatment system, for removal of volatile organic compounds (VOCs), that discharges a minimal amount of pollutants to the environment. An advanced oxidation process (AOP) system utilizing ozone, ultraviolet radiation, and hydrogen peroxide serves in this capacity. Packed tower aeration and activated carbon filtration are listed as best available technologies (BATs) by the Environmental Protection Agency (EPA) for the removal of VOCs in water. The disadvantage to these BATs is that they transfer the VOCs from the water medium to the air or carbon media respectively. Operation of the system began in May 1988 at a flow rate of 22.7 liters per minute (lpm) (6 gallons per minute (gpm)). An additional 102.2 lpm (27 gpm) of flow were added in October 1990. Various efforts to optimize and track the treatment unites efficiency have been carried out. A maximum influent reading of 26,590 parts per billion (ppb) of total VOCs has been recorded. Following the addition of flows, removal efficiency has averaged approximately 95%. Both air and water effluents are factored into this calculation. (author)

  15. Evaluation of the Hanford 200 West Groundwater Treatment System: Fluidized Bed Bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Looney, Brian B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jackson, Dennis G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dickson, John O. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Eddy-Dilek, Carol A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-05-12

    A fluidized bed reactor (FBR) in the 200W water treatment facility at Hanford is removing nitrate from groundwater as part of the overall pump-treat-reinject process. Control of the FBR bed solids has proven challenging, impacting equipment, increasing operations and maintenance (O&M), and limiting the throughput of the facility. In response to the operational challenges, the Department of Energy Richland Office (DOE-RL) commissioned a technical assistance team to facilitate a system engineering evaluation and provide focused support recommendations to the Hanford Team. The DOE Environmental Management (EM) technical assistance process is structured to identify and triage technologies and strategies that address the target problem(s). The process encourages brainstorming and dialog and allows rapid identification and prioritization of possible options. Recognizing that continuous operation of a large-scale FBR is complex, requiring careful attention to system monitoring data and changing conditions, the technical assistance process focused on explicit identification of the available control parameters (“knobs”), how these parameters interact and impact the FBR system, and how these can be adjusted under different scenarios to achieve operational goals. The technical assistance triage process was performed in collaboration with the Hanford team.

  16. Fungi from a Groundwater-Fed Drinking Water Supply System in Brazil.

    Science.gov (United States)

    Oliveira, Helena M B; Santos, Cledir; Paterson, R Russell M; Gusmão, Norma B; Lima, Nelson

    2016-03-09

    Filamentous fungi in drinking water distribution systems are known to (a) block water pipes; (b) cause organoleptic biodeterioration; (c) act as pathogens or allergens and (d) cause mycotoxin contamination. Yeasts might also cause problems. This study describes the occurrence of several fungal species in a water distribution system supplied by groundwater in Recife-Pernambuco, Brazil. Water samples were collected from four sampling sites from which fungi were recovered by membrane filtration. The numbers in all sampling sites ranged from 5 to 207 colony forming units (CFU)/100 mL with a mean value of 53 CFU/100 mL. In total, 859 isolates were identified morphologically, with Aspergillus and Penicillium the most representative genera (37% and 25% respectively), followed by Trichoderma and Fusarium (9% each), Curvularia (5%) and finally the species Pestalotiopsis karstenii (2%). Ramichloridium and Leptodontium were isolated and are black yeasts, a group that include emergent pathogens. The drinking water system in Recife may play a role in fungal dissemination, including opportunistic pathogens.

  17. Fungi from a Groundwater-Fed Drinking Water Supply System in Brazil

    Directory of Open Access Journals (Sweden)

    Helena M.B. Oliveira

    2016-03-01

    Full Text Available Filamentous fungi in drinking water distribution systems are known to (a block water pipes; (b cause organoleptic biodeterioration; (c act as pathogens or allergens and (d cause mycotoxin contamination. Yeasts might also cause problems. This study describes the occurrence of several fungal species in a water distribution system supplied by groundwater in Recife—Pernambuco, Brazil. Water samples were collected from four sampling sites from which fungi were recovered by membrane filtration. The numbers in all sampling sites ranged from 5 to 207 colony forming units (CFU/100 mL with a mean value of 53 CFU/100 mL. In total, 859 isolates were identified morphologically, with Aspergillus and Penicillium the most representative genera (37% and 25% respectively, followed by Trichoderma and Fusarium (9% each, Curvularia (5% and finally the species Pestalotiopsis karstenii (2%. Ramichloridium and Leptodontium were isolated and are black yeasts, a group that include emergent pathogens. The drinking water system in Recife may play a role in fungal dissemination, including opportunistic pathogens.

  18. Groundwater circulation and utilisation in an unconfined carbonate system - revealing the potential effect of climate change and humankind activities

    Science.gov (United States)

    Tóth, Ádám; Mádl-Szönyi, Judit

    2016-04-01

    Characteristics of gravitational groundwater flow systems in carbonate regions were presented by Mádl-Szönyi & Tóth (2015) based on theoretical considerations, identification and classification of groundwater flow-related field phenomena and numerical simulation. It was revealed that the changes of flow pattern in carbonate framework attributed to groundwater utilization and/or climate change are more apparent due to the effective hydraulic conductivity of carbonates. Consequently, natural or artificial disturbances of water level propagate farther, deeper and faster in carbonates than in siliciclastic basins. These changes could result in degradation and reorganization of hierarchical flow systems, modification of recharge and discharge areas and even alteration of physicochemical parameters (Mádl-Szönyi & Tóth, 2015). This paper presents the application of the gravity-driven regional groundwater flow concept to the hydrogeologically complex thick carbonate system of the Transdanubian Range, Hungary, depicting the flow pattern of the area and to a practical problem of a local study area, conflicts of interest of water supply and water use of a golf course. The question is how will the natural discharge on the golf course be influenced by the planned karst drinking water production well. In addition, the effects of climate change on this conflict were evaluated. We demonstrate the importance of the understanding the appropriate scale in karst studies and illustrate how the gravity-driven regional groundwater flow concept can help to determine it. For this purpose, the hydrogeological conditions of the study site were examined at different scales. The goals were to define the appropriate scale and reveal the effects of tectonic structures; and give prognoses for the possible impact of a planned drinking water well and climate change on the golf course based on numerical simulation. The study also showed the low geothermal potential of the area.

  19. The role of social learning for social-ecological systems in Korean village groves restoration

    Directory of Open Access Journals (Sweden)

    Eunju Lee

    2015-03-01

    Full Text Available Recently, social learning has been recognized as a means to foster adaptation to changing conditions, and more broadly, social-ecological systems resilience. However, the discussion of social learning and social-ecological resilience in different cultural contexts is limited. In this study we introduce the Korean Village Groves Restoration Project (VGRP through the lens of social learning, and discuss implications of the VGRP for resilience in villages impacted by industrialization and decline of traditional forest resources. We conducted open-ended interviews with VGRP leaders, government and NGO officials, and residents in four villages in South Korea, and found that villages responded to ecosystem change in ways that could be explained by the characteristics of social learning including interaction, integration, systems orientation, and reflection. However, the processes of learning varied among the four villages, and were associated with different levels of learning and different learning outcomes related to changes in village grove management and governance. The cultural and historical context can be used to help understand social learning processes and their outcomes in the Korean cases.

  20. Modeling of water transfer to aquifers: application to the determination of groundwater recharge by inversion in a complex hydrogeological system

    International Nuclear Information System (INIS)

    Hassane-Mamadou-Maina, Fadji-Zaouna

    2016-01-01

    Groundwater is the main available water resource for many countries; they are mainly replenished by water from precipitation, called groundwater recharge. Due to its great importance, management of groundwater resources is more essential than ever, and is achieved through mathematical models which offer us a better understanding of physical phenomena as well as their prediction. Hydrogeological Systems are generally complex thus characterized by a highly variable dynamic over time and space. These complexities have attracted the attention of many hydro geologists and many sophisticated models that can handle these issues and describe these Systems accurately were developed. Unfortunately, modeling groundwater recharge is still a challenge in groundwater resource management. Generally, groundwater models are used to simulate aquifers flow without a good estimation of recharge and its spatial-temporal distribution. as groundwater recharge rates show spatial-temporal variability due to climatic conditions, land use, and hydrogeological heterogeneity, these methods have limitations in dealing with these characteristics. To overcome these limitations, a coupled model which simulates flow in the unsaturated zone and recharge as well as groundwater flow was developed. The flow in the unsaturated zone is solved either with resolution of Richards equation or with empirical models while the diffusivity equation governs flow in the saturated zone. Robust numerical methods were used to solve these equations: we apply nonconforming finite element to solve the diffusivity equation and we used an accurate and efficient method for solving the Richards equation. In the natural environments, parameters that control these hydrological mechanisms aren't accurately known or even unknowns, only variations of piezometric heads are commonly available. Hence, ail parameters related to unsaturated and saturated flows will be identified by using only these piezometric data

  1. Fracture resistance of structurally compromised and normal endodontically treated teeth restored with different post systems: An in vitro study

    Directory of Open Access Journals (Sweden)

    Vajihesadat Mortazavi

    2012-01-01

    Full Text Available Background: With the aim of developing methods that could increase the fracture resistance of structurally compromised endodontically treated teeth, this study was conducted to compare the effect of three esthetic post systems on the fracture resistance and failure modes of structurally compromised and normal roots. Materials and Methods: Forty five extracted and endodontically treated maxillary central teeth were assigned to 5 experimental groups (n=9. In two groups, the post spaces were prepared with the corresponding drills of the post systems to be restored with double taper light posts (DT.Light-Post (group DT.N and zirconia posts (Cosmopost (group Zr.N. In other 3 groups thin wall canals were simulated to be restored with Double taper Light posts (DT.W, double taper Light posts and Ribbond fibers (DT+R.W and Zirconia posts (Zr.W. After access cavity restoration and thermocycling, compressive load was applied and the fracture strength values and failure modes were evaluated. Data were analyzed using two-way ANOVA, Tukey and Fisher exact tests (P<0.05. Results: The mean failure loads (N were 678.56, 638.22, 732.44, 603.44 and 573.67 for groups DT.N, Zr.N, DT.W, DT+R.W and Zr.w respectively. Group DT+R.W exhibited significantly higher resistance to fracture compared to groups Zr.N, DT.W and Zr.w (P<0.05. A significant difference was detected between groups DT.N and Zr.W (P=0.027. Zirconia posts showed significantly higher root fracture compared to fiber posts (P=0.004. Conclusion: The structurally compromised teeth restored with double taper light posts and Ribbond fibers showed the most fracture resistance and their strengths were comparable to those of normal roots restored with double taper light posts. More desirable fracture patterns were observed in teeth restored with fiber posts.

  2. Simulation of groundwater flow and hydrologic effects of groundwater withdrawals from the Kirkwood-Cohansey aquifer system in the Pinelands of southern New Jersey

    Science.gov (United States)

    Charles, Emmanuel; Nicholson, Robert S.

    2012-01-01

    The Kirkwood-Cohansey aquifer system is an important source of present and future water supply in southern New Jersey. Because this unconfined aquifer system also supports sensitive wetland and aquatic habitats within the New Jersey Pinelands (Pinelands), water managers and policy makers need up-to-date information, data, and projections that show the effects of potential increases in groundwater withdrawals on these habitats. Finite-difference groundwater flow models (MODFLOW) were constructed for three drainage basins (McDonalds Branch Basin, 14.3 square kilometers (km2); Morses Mill Stream Basin, 21.63 km2; and Albertson Brook Basin, 52.27 km2) to estimate the effects of potential increases in groundwater withdrawals on water levels and the base-flow portion of streamflow, in wetland and aquatic habitats. Three models were constructed for each drainage basin: a transient model consisting of twenty-four 1-month stress periods (October 2004 through September 2006); a transient model to simulate the 5- to 10-day aquifer tests that were performed as part of the study; and a high-resolution, steady-state model used to assess long-term effects of increased groundwater withdrawals on water levels in wetlands and on base flow. All models were constructed with the same eight-layer structure. The smallest horizontal cell dimensions among the three model areas were 150 meters (m) for the 24-month transient models, 10 m for the steady-state models, and 3 m for the transient aquifer-test models. Boundary flows of particular interest to this study and represented separately are those for wetlands, streams, and evapotranspiration. The final variables calibrated from both transient models were then used in steady-state models to assess the long-term effects of increased groundwater withdrawals on water levels in wetlands and on base flow. Results of aquifer tests conducted in the three study areas illustrate the effects of withdrawals on water levels in wetlands and on base

  3. Arsenic mobility in groundwater/surface water systems in carbonate-rich Pleistocene glacial drift aquifers (Michigan)

    International Nuclear Information System (INIS)

    Szramek, Kathryn; Walter, Lynn M.; McCall, Patti

    2004-01-01

    Within the Lower Peninsula of Michigan, groundwaters from the Marshall Formation (Mississippian) contain As derived from As-rich pyrites, often exceeding the World Heath Organization drinking water limit of 10 μg/L. Many Michigan watersheds, established on top of Pleistocene glacial drift derived from erosion of the underlying Marshall Formation, also have waters with elevated As. The Huron River watershed in southeastern Lower Michigan is a well characterized hydrogeochemical system of glacial drift deposits, proximate to the Marshall Fm. subcrop, which hosts carbonate-rich groundwaters, streams, and wetlands (fens), and well-developed soil profiles. Aqueous and solid phase geochemistry was determined for soils, soil waters, surface waters (streams and fens) and groundwaters from glacial drift aquifers to better understand the hydrogeologic and chemical controls on As mobility. Soil profiles established on the glacial drift exhibit enrichment in both Fe and As in the oxyhydroxide-rich zone of accumulation. The amounts of Fe and As present as oxyhydroxides are comparable to those reported from bulk Marshall Fm. core samples by previous workers. However, the As host in core samples is largely unaltered pyrite and arsenopyrite. This suggests that the transformation of Fe sulfides to Fe oxyhydroxides largely retains As and Fe at the oxidative weathering site. Groundwaters have the highest As values of all the waters sampled, and many were at or above the World Health limit. Most groundwaters are anaerobic, within the zones of Fe 3+ and As(V) reduction. Although reduction of Fe(III) oxyhydroxides is the probable source of As, there is no correlation between As and Fe concentrations. The As/Fe mole ratios in drift groundwaters are about an order of magnitude greater than those in soil profiles, suggesting that As is more mobile than Fe. This is consistent with the dominance of As(III) in these groundwaters and with the partitioning of Fe 2+ into carbonate cements. Soil

  4. Vulnerability of deep groundwater in the Bengal Aquifer System to contamination by arsenic

    Science.gov (United States)

    Burgess, W.G.; Hoque, M.A.; Michael, H.A.; Voss, C.I.; Breit, G.N.; Ahmed, K.M.

    2010-01-01

    Shallow groundwater, the primary water source in the Bengal Basin, contains up to 100 times the World Health Organization (WHO) drinking-water guideline of 10g l 1 arsenic (As), threatening the health of 70 million people. Groundwater from a depth greater than 150m, which almost uniformly meets the WHO guideline, has become the preferred alternative source. The vulnerability of deep wells to contamination by As is governed by the geometry of induced groundwater flow paths and the geochemical conditions encountered between the shallow and deep regions of the aquifer. Stratification of flow separates deep groundwater from shallow sources of As in some areas. Oxidized sediments also protect deep groundwater through the ability of ferric oxyhydroxides to adsorb As. Basin-scale groundwater flow modelling suggests that, over large regions, deep hand-pumped wells for domestic supply may be secure against As invasion for hundreds of years. By contrast, widespread deep irrigation pumping might effectively eliminate deep groundwater as an As-free resource within decades. Finer-scale models, incorporating spatial heterogeneity, are needed to investigate the security of deep municipal abstraction at specific urban locations. ?? 2010 Macmillan Publishers Limited. All rights reserved.

  5. Rationales behind irrationality of decision making in groundwater quality management.

    Science.gov (United States)

    Ronen, Daniel; Sorek, Shaul; Gilron, Jack

    2012-01-01

    This issue paper presents how certain policies regarding management of groundwater quality lead to unexpected and undesirable results, despite being backed by seemingly reasonable assumptions. This happened in part because the so-called reasonable decisions were not based on an integrative and quantitative methodology. The policies surveyed here are: (1) implementation of a program for aquifer restoration to pristine conditions followed, after failure, by leaving it to natural attenuation; (2) the "Forget About The Aquifer" (FATA) approach, while ignoring possible damage that contaminated groundwater can inflict on the other environmental systems; (3) groundwater recharge in municipal areas while neglecting the presence of contaminants in the unsaturated zone and conditions exerted by upper impervious surfaces; (4) the Soil Aquifer Treatment (SAT) practice considering aquifers to be "filters of infinite capacity"; and (5) focusing on well contamination vs. aquifer contamination to conveniently defer grappling with the problem of the aquifer as a whole. Possible reasons for the failure of these seemingly rational policies are: (1) the characteristic times of processes associated with groundwater that are usually orders of magnitude greater than the residence times of decision makers in their managerial position; (2) proliferation of improperly trained "groundwater experts" or policymakers with sectoral agendas alongside legitimate differences of opinion among groundwater scientists; (3) the neglect of the cyclic nature of natural phenomena; and (4) ignoring future long-term costs because of immediate costs. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

  6. Biogeochemistry of Arsenic in Groundwater Flow Systems: The Case of Southern Louisiana

    Science.gov (United States)

    Johannesson, K. H.; Yang, N.; Datta, S.

    2017-12-01

    Arsenic (As) is a highly toxic and carcinogenic metalloid that can cause serious health effects, including increased risk of cancers, infant mortality, and reduced intellectual and motor function in children to populations chronically exposed to As. Recent estimates suggest that more than 140 million people worldwide are drinking As-contaminated groundwater (i.e., As ≥ 10 µg kg-1), and the most severely affected region is the Ganges-Brahmaputra-Meghna delta in Bangladesh and India (i.e., Bengal Basin). Arsenic appears to be mobilized to Bengal Basin groundwaters by reductive dissolution of Fe oxides in aquifer sediments with the source of the labile organic matter occurring in the aquifer sediments. Studies within the lower Mississippi River delta of southern Louisiana (USA) also reveal high As concentrations (up to 640 µg kg-1) in shallow groundwaters. It is not known what affects, if any, the elevated groundwater As has had on local communities. The regional extent of high As shallow groundwaters is controlled, in part, by the distribution of Holocene sediments, deltaic deposits, and organic-rich sediments, similar to the Bengal Basin. Field and laboratory studies suggest that As is largely of geogenic origin, and further that microbial reduction of Fe(III)/Mn(IV) oxides/oxyhydroxides within the sediments contributes the bulk of the As to the groundwaters. Incubation studies are supported by biogeochemical reactive transport modeling, which also indicates reductive dissolution of metal oxides/oxyhydroxides as the likely source of As to these groundwaters. Finally, reactive transport modeling of As in shallow groundwaters suggests that sorption to aquifer mineral surfaces limits the transport of As after mobilization, which may explain, in part, the heterogeneous distribution of As in groundwaters of southern Louisiana and, perhaps, the Bengal Basin.

  7. Nitrogen removal in shallow groundwater below three arable land systems in a high nitrogen loading region

    Science.gov (United States)

    Yan, X.; Zhou, W.

    2017-12-01

    The Taihu Lake region (TLR) is one of the most intensive agricultural regions with high nitrogen (N) loading in eastern China. Large inputs of synthetic N fertilizer have led to a series of environmental problems including eutrophication of surface waters, nitrate (NO3-) pollution of groundwater. To fully evaluate the risk of NO3- on groundwater environments, it is necessary to know the natural NO3- removal ability. In this study, denitrification capacity was assessed for two years through measuring the concentration of different N species (NO3-, NH4+, TN, excess N2 and dissolved N2O) in groundwater below three typical agricultural land-use types in the TLR. The results suggested that the conversion of paddy field (PF) to vineyard (VY) and vegetable (VF) significantly increased the groundwater NO3-N concentration, but denitrification consumed 76%, 83% and 65% of the groundwater NO3-N in VY, VF and PF, respectively. Because of the low O2 and high DOC concentrations in groundwater, denitrification activity was high in the study sites, resulting in high excess N2 accumulation in groundwater, and the concentration even exceeded the total active N in the deep layer. The large amounts of excess N2 observed in the VY and VF over all the sample times indicated that considerable N was stored as gaseous N2 in groundwater and should not be ignored in balancing N budgets in aquifers where denitrification is high. Our results also demonstrated that the indirect N2O emission factor (EF5-g) in VY (0.0052)and VF (0.0057)was significantly higher than PF (0.0011)as well as higher than the IPCC default values (0.0025. In view of the increasing trend of paddy fields being converted to uplands combined with the low GWT in the TLR, we thus concluded that the risk of NO3- contamination in groundwater and indirect N2O emission will intensify below arable land.

  8. Emergy assessment of ecological compensation of groundwater overexploitation in Xuchang city

    Science.gov (United States)

    Lv, C.; Ling, M.; Cao, Q.; Guo, X.

    2017-12-01

    In recent 30 years, the amount of groundwater extraction in China is increasing at a rate of 2.5 billion m3 per year. And the growing amount led to form a predatory exploitation in many parts, and caused serious exploitation problems, such as land subsidence, sea water intrusion, surface runoff reduction, vegetation decline, groundwater pollution, and so on. Ecological compensation of overexploitation has become an important mean to adjust the environmental benefits distribution relationship related to the groundwater system and to alleviate the problem of groundwater overexploitation. Based on the ecological economics emergy value theory and analysis method, the emergy loss value calculation method of eco-environmental problems caused by groundwater overexploitation, such as environmental land subsidence (collapse), salt (sea) water intrusion, surface runoff reduction, vegetation deterioration and groundwater pollution, is established, and the assessment method, which takes emergy loss value as the quantity of ecological compensation of groundwater overexploitation, is put forward. This method can reflect the disaster loss degree of groundwater overexploitation more intuitively, and it helps to improve, manage and restore a series of problems caused by groundwater overexploitation, construct a scientific and reasonable groundwater ecological compensation mechanism, and provide good ecological security for the sustainable and healthy development of national economy in our country. Taking Xuchang city as an application example, the results showed that the ecological economic loss of groundwater overexploitation was 109 million in 2015, accounting for 0.3% of the total GDP. Among them, the ecological economic loss of land subsidence is the largest, which was 77 million, accounting for 70.3% of the total loss, the second one is surface runoff reducing loss, which was 27 million, accounting for 24.7% of the total loss, and underground water pollution loss is the

  9. Investigation by multivariate analysis of groundwater composition in a multilayer aquifer system from North Africa: A multi-tracer approach

    Energy Technol